Special Section : Development of Biotechnological Process


Maximization of Glucose Production Using Hydrogen Peroxide as an Alkaline Pretreatment of Sweet Sorghum Bagasse

P. Viveros Reyes, L. López Zamora, G. Partida Sedas, M. G. Aguilar Uscanga

  • Abstract

    Sweet sorghum bagasse represents an alternative source of fermentable sugar production due to its high fiber content. Its main advantages over other raw materials are related to the fact that are drought tolerant crops, able to be easily harvested twice a year, and namely, most of sweet sorghum genotypes serve as a source of fermentable sugars for the production of biofuls such as ethanol. The conversion of sweet sorghum bagasse allows to obtain juice and lignocellulosic material with excellent yields. The lignocellulosic material (bagasse) is mainly composed of cellulose, hemicellulose and lignin besides small amounts of pectin, proteins, chlorophyll, fats and ashes. Basically cellulose forms a skeleton that is surrounded by hemicellulose and lignin, being the main obstacle in glucose production during enzymatic hydrolysis of bagasse from sweet sorghum the lignin associated with this agroindustrial residue, since adsorbed the cellulase preventing its action on the cellulose glycosidic bonds. To hydrolyze cellulose, and then perform the fermentation of sugars, it is necessary to pretreat the lignocellulosic material, to modify its structure. For this, the aim of this work was to carry out the lignocellulosic material pretreatment via alkaline hydrolysis, considering an experimental design Box-Behnken, considering as independent variables the concentration of H2O2 (3.5, 4.5 and 5.5 % v/v), pretreatment time (15, 25 and 35 h) and liquid-solid ratio (RLS) (10, 17 and 24 mL/g) and as a response variable xylose concentration (g/L), reaching a maximum conversion of 46.713 g/L using the variables: H2O2 concentration of 4.5 %, time of 25 hours and liquid-solid ratio 17:1. Statistically was determined that the most appropriate values are RLS = 18.13:1, time = 26.98 hours and H2O2 concentration = 4.65 %, whichwhen considered in the proposed model adjustment reflects a conversion<


Changes in the Quantity of Phenolic Compounds in Peppers (Capsicum Annuum L.) Sprinkled with Elicitors Under Cold Stress

Sandra Neli Jimenez-Garcia, Moises Alejandro Vazquez-Cruz, Lina Garcia-Mier, Ramon Gerardo Guevara-Gonzalez, Irineo Torres-Pacheco, Rosalía Virginia Ocampo-Velazquez, Andres Cruz-Hernandez, Ana Angelica Feregrino-Perez

  • Abstract

    Pepper is one important cultivated peppers in Mexico to commercial and industrialized profiles, however, grow and development are affected by environmental changing, especially low temperatures that cause important culture damage. In these words, it was developed a defensive mechanism against abiotic stress activated by inductor agents. The peppers seedling defensive response was evaluated by spectroscopy quantitative analysis using phenolic compounds. There was a relationship between elicitor’s concentration and chilling tolerance, and the best protection was obtained from plants treated with 6.7 mM salicylic acid after 24 hours. Our finding that salicylic acid could be used as a seed treatment to prevent crop losses in pepper due to chilling stress may have significant practical applications.


Use of Myoelectric Signals in Hand Prosthesis

Armando Josué Piña Díaz, Marco Antonio Hernández Rodríguez, Christopher René Torres San Miguel, Beatriz Romero Ángeles, Guillermo Urriolagoitia Sosa, Guillermo Manuel Urriolagoitia Calderón

  • Abstract

    The electromyographic signals (EMG) or also known as myoelectric signals are electrical signals produced by movement of contraction and relaxation of muscles. Since they can be generated voluntarily, are widely used for their functionality to control human - machine interfaces. Investigations relating to the acquisition of these myoelectric signals have been used mainly for the purpose of operating various prosthetic devices for different type of limbs. Obtained as a result, this kind of prosthesis can be handled through the response generated by these signals to emulate the natural motion of the limb replaced. A human being is primarily a functional entity and his body and intelligence are the essence of what it does. The main organs for the physical manipulation of the environment are the hands1. The hand has been the key partner of the brain to turn thought into an action; in it, the ideas are mechanically translated into an action, creating hierarchical representations to configure the necessary processes in the control of movement.


Characterization of Lignocellulosic Biomass Using Five Simple Steps

Hector Toribio-Cuaya, Lorena Pedraza-Segura, Samuel Macías-Bravo, Ixel Gonzalez-García, Ruben Vasquez-Medrano and Ernesto Favela-Torres

  • Abstract

    The pretreatment of the lignocellulosic biomass is the most important step in the biorefinery processes, because it has a high influence on the yield and efficiency of the subsequent treatments. In order to choose the most suitable pretreatment is necessary to characterize the cellulosic feedstock adequately. TAPPI and NREL methods have been used widely in recent years. The first one is useful to characterize the pulp and paper feedstock, and the second one is used in the biofuels production. However these methods are not fully accurate for determining lignocellulosic materials composition, such as corncob. Therefore in this work, we improved the characterization method modifying some steps. The stages  fextraction and quantification of lignin and hemicellulose were enhanced by implementing separate procedures for each component. This methodology has been used successfully for different types of corncob, municipal solid waste and water hyacinth. 


Effect of Carbon: Nitrogen Ratio on the Bacillus thuringiensis Spore Production

Stephanie Talia Méndez-Morales, Lourdes Andrea García-Rodríguez, María de Lourdes Moreno-Rivera, Sergio García-Salas

  • Abstract

    The production of Cry protein and spore by Bacillus thuringiensis is related to the formulation of the culture medium and operating conditions of the bioreactor, such as agitation and aeration. Cry proteins are responsible for the bioinsecticide activity of B. thuringiensis. In this work the effects of carbon to nitrogen (C:N) ratio and carbon concentration on spore production of B. thuringiensis HD23 are reported. The spore production was determined at C:N ratios from 4 to 10, and at carbon source concentrations of 10 g/L, 20 g/L and 30 g/L for each C:N ratio. The nitrogen source was soybean meal (hydrolyzed and non-hydrolyzed); while carbon source was glucose. Experiments were carried out in shake flasks. The results shown that with the non-hydrolyzed soybean meal, the highest spore concentration (3.7 x 1012 espores/L) and the highest spore productivity (1.54 x 1011 spores/L h) were achieved at a C:N ratio of 10 and at a glucose concentration of 20 g/L; whereas with the hydrolyzed soybean meal, the spore concentration (4.3 x 1012 spores/L) and spore productivity (1.79 x 1011 spores/L h) were higher than with the nonhydrolyzed soybean meal, and these were also achieved at a C:N ratio of 10 and at a glucose concentration of 20 g/L. At these conditions the count of crystals produced was 3.0 x 1012 crystals/L. Also, the maximum specific growth rate was 0.6 h-1 at the better conditions of C:N ratio and glucose concentration. The inoculums growing in log phase and cultured on the complex medium allow reducing considerably the lag phase. Finally, when B. thuringiensis HD23 is grown using the best formulation of the culture medium obtained inthis work and a bioreactor with a high oxygen transfer, may be possible that the productivity can be even higher.


Yield And Quality of Alginate from Brown Seaweed Halidrys dioica.

Miguel Ángel Villa Arce, Gustavo Hernández Carmona, Araceli Rodríguez Cuautle & Ana Laura González Castro

  • Abstract

    Alginates demand has increased considerably worldwide due to its various industrial applications, mainly associated with their rheological properties. This study aimed to analyze the yield and quality parameters (viscosity and gel strength) of the alginate obtained from Halidrys dioica seaweed, in order to determine the feasibility of using this species as an alternative resource for the production of this important phycocolloid. Alginate extraction was performed by ion exchange reactions, beginning with an acidic pre-extraction (HCl 1N), followed by alkaline extraction (Na2CO3 10%) and subsequently filtered. The clarified solution was precipitated in alcohol (96%) to being obtained alginate fibers, which are being dried to finally determine yield. Determining the quality of the alginate was performed using a Brookfield viscometer (Model LTV) and gel strength was measured with a texture analyzer (Model TA.TXPlus). Based on our results, the brown alga H. dioica has great potential to be considered as an alternative resource for extraction of alginates. It had a yield of 20% (comparable with the genera Macrocystis and Eisenia). Their quality parameters were acceptable, the viscosity of 80 mPa.s thus may have application as a thickener in food industries, while its gel strength which is 939g cm-2 has potential for biotechnological application type, pharmaceutical and food industries.


Amaranth (Amaranthus Hypochondriacus L.): Use of Lignocellulosic Biomass to Obtain Antioxidant extracts Through Acid Hydrolysis

Maria Belem Arce-Vazquez, Ezequiel Delgado Fornué, María Esther Esquivel Rosales and Jorge Soriano-Santos

  • Abstract

    Amaranth is cultivated in Mexico and other countries because of its nutritional protein value. After its grain is harvested, roughly 550,000 tons per year of lignocellulosic biomass (LB) is generated. Amaranth LB (ALB) can be used as forage but its use is limited; mainly it is burned and consequently pollutes the air. Therefore, the objective of this work was to utilize the ALB, for extracting polyphenols, and processing ALB in order to obtain added value extracts with antioxidant activity (AOxA). ALB was oven dried and its fiber content was 21.0±1.3 g/100 g dry weight (dw). Total polyphenols content of an aqueous extraction obtained at 85°C for 5 min of dried ALB polyphenols was 7.6±0.56 mg gallic acid equivalent (GAE)/g dw. These extracts were called extractable polyphenols (EPP). The best conditions to obtain the called non EPP (NEPP) of ALB were obtained using the surface response method. The treatment using 5% (w/v) H2SO4 at 111°C for 90 min yielded 41, 2 mg GAE/g dw of TP. AOxA of EPP and NEPP expressed as their IC50 values assessed by the reduction of DPPH• method were 1.56 and 1.66 mg GAE/g dw, respectivaely. These extracts were also concentration dependent of Fe2+ at 0-1.4(GAE)/g dw and 0-0.009(GAE)/g dw, respectively. ALB may be processed to afford EPP and NEPP which may be an important natural commodity with AOxA for food industry. 


Tree Microalgae Strains Culture Using Human Urine and Light

Luis G. Torres, Marcos Martínez, J. Diego García, Luis C. Fernández

  • Abstract

    The use of microalgae lipids or the whole biomass for generation of biodiesel, methane, hydrogen and other valuable fuels is very attractive. Among the many requirements for microalgae growth is a specific culture media, which provides the cells of macro and micronutrients. These are specific for every strain and represent a cost for the biomass and/or the specific target production. Human urine has a potential for different activities, such as greenhouse culturing of microalgae, zooplankton and vegetables. The aim of this work was to demonstrate that three strains of microalgae are capable of growing in human urine dilutions, and they can produce lipids in amounts similar to those produced when growing in a commercial media (BBM). The three evaluated strains can be cultured in mediacontaining 1:50 to 1:200 dilutions, giving biomass concentration higher than those found when using BBM media. Regarding the lipids production, values were quite near than those obtained when growing the microalgae in BBM media. Nevertheless, the product of themaximum absorbency x lipid concentration values are very similar for Chlorella vulgaris and Scenedemus sp growing in urine to those observed when growing in BBM media. This finding has tremendous implications over the biodiesel based on microalgae process. Culture media could be formulated almost exclusively with urine. Next step of this project will be the optimization of media containing human urine and small amounts of some essential metals such as Cu, Fe, Mg, Zn etc. 


Development of a Powder Formulation Based on Bacillus cereus Spores for Biological Control of Fusarium verticillioides in Maize Plants

JC Martínez-Álvarez, KI Medellín-Bool, C Castro-Martínez, R Gutiérrez-Dorado, P Sánchez-Peña, IE Maldonado-Mendoza

  • Abstract

    Fusarium verticillioides is an important fungal pathogen of maize plants. The use of biological agents against plant pathogens is a very promising control strategy and includes treatment of seeds, plants and soil with antagonistic organisms. Inadequate large scale production and inappropriate formulation technology are factors that limit success in the use of biocontrol agents. We have used different statistical tools to determine the most influential culture medium variables for Bacillus cereus spores production. With spore’s production reaching 1.36 × 109 UFC/mL, a talc based powder formulation was prepared and evaluated. Powder formulation showed no negative effects on evaluated parameters. Viability of spores ranged between 80% and 53% after six months and one year storage at room temperature respectively. Moreover, this formulation was capable of controlling other eight maize phytopathogenic fungi besides F. verticillioides in vitro. Results suggest that talc-based formulation of B. cereus spores may be a good method for industrial scale production.


Molecular Identification and Production of Phytohormones of Bacteria Isolated from Rhizosphere of Prosopis glandulosa in Mexicali Valley

Lizbeth Moreno-Ramírez and Daniel González-Mendoza

  • Abstract

    The Mexicali Valley (semi-arid area) is an important agricultural region in the northwest of Mexico. One of the main problems in intensive crop production in Mexicali Valley is the dependence on the use of phosphate fertilizer and water rich in salts used in irrigation of crops. Therefore, in the present study the objective was isolation from rhizosphere of mesquite (Prosopis glandulosa) in Mexicali valley of phosphate solubilization bacteria (PSB) that were able to produce phytohormones. The strains were identified by 16S ribosomal DNA the analysis revealed that ICA01, ICA02Ba, ICA03Bs and ICA04Ma strains belonged to the genus Acinetobacter spp., all strains were able to solubilize phosphate, decrease pH medium and phytohormones producing. The presence of clearing zone in the media with respect to time suggested an increase in acid secretion and thus conversion of insoluble phosphate to soluble form. The phosphate solubilization potential observed may be attributed to the ability to reduce pH of the surroundings, either by releasing organic acids or protons. Our studies suggested that this Acinetobacter strains decreased medium pH are efficient phosphate solubilizing strains.


Develop of 3D Pixeled Phantom Brain to Simulate There Interaction with Electromagnetic Fields

Rafael Rojas and José Antonio Calderón

  • Abstract

    Matter-radiation appears in situations like: medical radiology or electric high tension systems. Make a prediction about the effects of radiation over the organic tissue require the Maxwell’s equations solution. Many investigators works in numerical solutions in 2D with organic pixeled phantoms, but there are designed with simple geometrical structures, and when somebody proposed a 3D model, just take a 2D slice, because they spend less memory. Our objective is solve the Maxwell’s equation using Finite Element, to obtain the electric and magnetic fields, over a realistic pixeled phantom human’s brain, this model was developed for us, and after we calculate the induced current density produced on the brain. To design a pixeled anatomical phantom from Magnetic Resonance Imaging, we take a stack of image slices from organ, and using a computational packet we obtain a rendering 3D image. This anatomical model, have electric and magnetic properties in function of frequency. The 3D pixeled imaging generated was used to apply this methodology to a subway or any electric transport with catenary line, there transport 600A of electrical current with 750V of electric tension. We propose a distance between catenary and driver just of 50cm.


Evaluating the Effectiveness of A Biological Filter Through Physical and Chemical Methods.

Germán Melo

  • Abstract

    In the savannah of Bogotá agriculture is the main economic activity of the human population, the water used for this activity by 73% comes from the Bogotá River, its tributaries and deep wells that threaten human health. The research evaluated the action of a wetland type filter for irrigation water through a physical system, chemical and biological component. The methodology used was adjusted to international protocols, the results show that the artificial system is a viable option for improving the quality of irrigation water that allows a high percentage reduction of pathogenic microorganisms proposal. The joint work of the physical system and biological filtration system shows positive results between pre and post measurements of hydraulic retention. The performance of the subsystems, aquatic macrophytes and microbial action jointly in the rhizosphere and its outskirts biodepurante generated rapid action. The treated water was used in cultured Spinacia oleracea and a control group where growth and crop development was favored obtaining an increase in leaf area, wet weight and significant improvement in morphology.


Automation of pH in a UASB bioreactor applying fuzzy techniques, using the LabVIEW platform and ATmega controllers.

I.O. Rico-Asención, C. Guerrero-Barajas, M.G. Ramírez-Soteloand A.I. Cabrera-Llanos 

  • Abstract

    This abstract presents a prototype for automation and control of pH, applied to a recirculation bioreactor bottom-up, implementing the use of Lab VIEW and ATMEGA328P platform for online monitoring. The prototype is constructed of 5mm thick acrylic, which is divided into four separate tanks, three for the supply of different substances to be used in the process of measuring the pH and one for the waste. The substances are pumped with a pump for submersible distilled water and a peristaltic pump to the reactor for nutrients; controlling the flow of the sample is performed by solenoid valves, the control components is performed by a control circuit, with two stages: one part for conditioning the signal transmitted from the computer via the ATMEGA328P, and the other for the change from low to high power, which allows controlling the above elements. The pH measurement is performed by using a commercial electrode. The fuzzy control algorithm was programmed in LabVIEW. A set of rules, which are awarded label of belonging associated with a pH level, which, in the comparison of acquired tagged value generated corresponding to the associated event for pH control action was programmed.


Analysis Of the Temperature and Aeration Effect in the Growth of the Bacterium Bacillus Spp. IBT42 And its Yield of PHB

César Galicia Beltrán, Leticia López Zamora, Daniel Segura González and ibertad A. Adaya García

  • Abstract

    This abstract presents a prototype for automation and control of pH, applied to a recirculation bioreactor bottom-up, implementing the use of Lab VIEW and ATMEGA328P platform for online monitoring. The prototype is constructed of 5mm thick acrylic, which is divided into four separate tanks, three for the supply of different substances to be used in the process of measuring the pH and one for the waste. The substances are pumped with a pump for submersible distilled water and a peristaltic pump to the reactor for nutrients; controlling the flow of the sample is performed by solenoid valves, the control components is performed by a control circuit, with two stages: one part for conditioning the signal transmitted from the computer via the ATMEGA328P, and the other for the change from low to high power, which allows controlling the above elements. The pH measurement is performed by using a commercial electrode. The fuzzy control algorithm was programmed in LabVIEW. A set of rules, which are awarded label of belonging associated with a pH level, which, in the comparison of acquired tagged value generated corresponding to the associated event for pH control action was programmed.


Study Of The Efeect Of Stirring Speed Of Glucose Fermentation Using Bacteria Zymomonas mobilis

Leticia López-Zamora, Ángel Evangelista, 1Ricardo Castellanos

  • Abstract

    The aim of this research is to study the effect on the stirring speed at the potato starch fermentation process using Zymomonas mobilis bacteria. Eight stirring speed were tested in a range of 80 to 150 rpm, all experiments were performed by duplicate in a 72 g period to maintain a constant pH. The increased conversion of sugars and the highest concentrations of ethanol were obtained at a stirring speed of 150 rpm, agitation favored mixing wort allowing greater contact Zymomonas mobilis bacteria. During fermentation process, pH, °Brix and CFU were monitored to ensure the adequate performance of the process. pH was stable in the range of 4 – 5. The °Brix was reduced 15.4 % at a stirring speed of 150 rpm, indicating greater consumption of sugars. When performing the fermentation process employing potato starch and Zymomonas mobilis at different stirring speeds, we found that agitation at 150 rpm showed a 9.3 % yield greater than 80 rpm. 20.4% higher bioethanol was obtained at 150 rpm. Stable conditions favored the process. A gas chromatographic analysis showed that the major impurities was obtained at slow stirring speed.


Fructanase Activity in Yeasts Isolated from Mezcal Must

Erika A. De la Cruz-Arguijo, Patricia Vital, Sergio A. Huerta, Claudia Patricia Larralde-Corona, José A. Narváez-Zapata

  • Abstract

    The main sugar in agave musts for mezcal production is fructose.. However, also a huge amount of agave residues are produced, generally known as agave bagasse, which could potentially be reused in the elaboration of high fructose syrups. We analyzed the fructanase activity of 32 yeast naturally present in Tamaulipas´ agave musts. A preliminary analysis with all strains using sucrose as substratum (invertase activity) was conducted and 5 strains were chosen, which included species of Kluyveromyces, Saccharomyces and Pichia genera, and for those, a broader enzymatic activity was characterized over fructans of A. tequilana (FAT), inulin and levan. All strains showed an increased enzyme activity in the FAT substrate, whether in some cases they had no activity with sucrose and inulin. The specificity of the yeasts towards fructans of A. tequilana was higher than the one obtained using pure inulin. The Kluyveromyces strains showed the highest activity for the sucrose (invertase activity), however all strains tested showed a better activity when the substrate used was FAT. This demonstrates the potential of these strains to be used for the production of high efficiency fructanases for recycling of residues of the mezcal and tequila industries.


Flocculation of Yeasts from Mezcal and Its Implication Under Heat Stress Conditions

Israel Vergara, Amanda Oliva, Francisco Quiroz, Claudia Patricia Larralde-Corona, José A. Narváez-Zapata

  • Abstract

    Flocculation is the asexual aggregation of cells mediated by lectine-like proteins on presence of Ca2+ and as a response mechanism to stress is a desired trait due to the ease of biomass separation at the end of the fermentation. In this work a total of 19 Saccharomyces and non-Saccharomyces yeasts chosen from CBG-IPN mezcal strain collection were screened to select those resistant to 40 ºC on 2% YPD o YPF agar (glucose or fructose respectively). Fermentative performance was determined on 10% YPG or YPU. Flocculation was evaluated in an 8 mM citrate/CaCl2 buffer, and observed under confocal microscopy by staining cells with 0.4 % Solophenyl Flavine 7GFE-500. On agar plates there were two distinct groups; the first one represented for the most tolerant strain Saccharomyces cerevisiae (Sc3Y8), and the second one represented by strain Kluyveromyces marxianus (Km1D5). Strains selected showed an efficient fermentative performance at 30 ºC and 40 ºC in contrast to the control strain Fermichamp, which performed badly on fructose consumption at 40ºC and showed a diminished cell viability. We propose that changes on the cell wall can contribute to the high viability and heat-stress tolerance. Kluyveromyces strain showed the highest tolerance to heat-stress but did not flocculate.


Potential Use of Mezcal Yeasts Isolates for Wine Fermentation

Francisco J. De la Torre-González, José A. Narváez-Zapata, Patricia Taillandier, Claudia Patricia Larralde-Corona

  • Abstract

    The fermentation performance was assessed for three mezcal S. cerevisiae strains in mixed cultures with three mezcal non-Saccharomyces strains (belonging to Kluyveromyces marxianus, Torulaspora delbrueckii or Zygosaccharomyces bailii species) and the commercial strain Fermichamp was used as a control. Experiments were carried out in 30 mL of pasteurized red grape juice in 50 mL mini-bioreactors tubes (Corning Science, México) at 30°C and 75 rpm inoculated an initial level of 3x106 cells/mL and the mixed fermentations at a ratio of 9:1 of non-Saccharomyces: S. cerevisiae. Fermentations were monitored by CO2 release. Primary metabolites production was measured by HPLC and volatiles by GC. Cell populations were determined by OD600nm and yeast viability was determined by plate counting in nutrient and differential WL agar. The fermentation rate varied markedly depending on the yeast combination used. The evolution of biomass in pure and mixed cultures of non-Saccharomyces and S. cerevisiae revealed that cell populations and fermentation metabolites were similar in all cases except with acetic acid. The diverse metabolic capabilities of the different yeasts analyzed allowed us to select and classify our strains as potential wine producers due to their desirable technological features for its high production of ethanol and low acetic acid concentration.


Alcohol Production in Synthetic Medium Added with Different Sugars

Tania González-Flores; María de los Ángeles Sánchez-Contreras; Neith Aracely Pacheco-López, Ingrid Rodríguez-Buenfil

  • Abstract

    The aim of this research was to obtain a preliminary sugar assimilation profile and to determine the alcohol production of two wild yeasts on different sugars. The wild yeasts identified as C. glabrata N1 and W. anomalus API-1 were isolated from fermented orange juice and fistulated bovine rumen, respectively, both from Yucatan, Mexico. Growth, alcohol production and their kinetic parameters were determined for both yeasts in minimal salt broth added with different carbon sources. Carbohydrate assimilation profile indicated that both strains assimilate preferentially, fructose, glucose and mannose. The alcoholic fermentation was carried out in static culture at 40°C and pH 4.5; where the N1 strain had a better performance than API-1 strain. The best substrate for N1 strain growth and alcohol production was fructose, while for API-1 strain it was glucose. Although both strains presented the ability to ferment glucose, fructose and sucrose, it was not possible to detect alcohol production on galactose or xylose as a carbon source. In conclusion, the strain and the carbon source showed a statistical effect over the kinetic parameters of growth and alcohol production, being more suitable for ethanol production C. glabrata N1 strain, reaching 12.53 g/L on fructose, 11.08 g/L on glucose and 6.87 g/L on sucrose as substrates.


Production and Purification of N-acetylglucosaminidases and Endochitinases of Lecanicillium lecanii in Submerged Culture

Jesús Rojas-Osnaya, Ulises Carrasco, Angélica Ramos-Puebla, Guadalupe Villa-Lerma, Zaizy Rocha-Pino, Humberto González-Márquez, Keiko Shirai

  • Abstract

    Poly[1,4-(N-acetyl--D-glucosaminide)] glycanohydrolase (Endo), EC, depolymerized chitin to release N-acetyl--D-glucosamine (GlcNAc), chitobiose, and chitooligosaccharides. These compounds are degraded by chitodextrinases (also EC and -N-acetyl-D-hexosaminidase (Nhase), EC, to produce GlcNAc and chitobiose. Despite of reports on chitinases production by Lecanicillium lecanii in submerged (SmC) and solid state cultures, there is scarce information related to the specificity of chitinases of L. lecanii, therefore, this study focus on production and purification of chitinases for further studies. Nhases and Endo were produced from L. lecanii in submerged culture with the addition of coloidal chitin as inducer. Enzyme purification was conducted by salting out with ammonium sulphate, followed by gel filtration and anionic exchange chromatographies. Nhase and Endo activities were determined for each purification step and molecular weights corroborated by electrophoresis. Several purified proteins were attained with 50 kDa and 39 kDa for Nhase and Endo, respectively. Ongoing work is directed toward determination of enzymatic specificities.


Effects of Wet Pre-Treatment on the Pasting Properties of Extruded Corn Flours

Contreras-Jiménez Brenda, Gaytán-Martínez Marcela, Morales-Sánchez Eduardo, Pless Reynaldo C.1, Velázquez Gonzalo, González-Jasso Eva

  • Abstract

    Extrusion is an efficient technology which can be used to obtain corn flour; however, the viscosity of extruded flour is lower than that of nixtamalized corn flour. Based on previous investigations it is believed that a wet treatment of the corn before extrusion can improve the viscosity of the masa. The aim of this investigation was to study the effect of a wet pre-treatment of the cornmeal on the viscosity of extruded corn flours. The wet pre-treatment consisted in stepping the milled corn in 0, 1 or 2% w/w Ca(OH)2 for 0.016, 5, and 10 h at 4°C; then the stepped material was drained and extruded at 80°C at 20 rpm. The extruded samples were dried at 45°C/24 h and evaluated for water absorption capacity (WAC) and viscosity. The results were evaluated by ANOVA and the Tukey test. Results show that the viscosity increased with the wet pre-treatment time and the Ca(OH)2 concentration. A correlation was found between the WAC and the viscosity. We conclude that the corn flours extruded after pre-treatment with Ca(OH)2 have less damage and therefore these samples have high viscosity. The wet pre-treatment can be used to improve the properties of corn flours obtained by alternative technologies, extrusion or others.


Biocatalytic Reduction of Aromatic Aldehydes Using Seeds as Enzyme Source

Rosa Martínez, Fadia Cervantes, Aida Solís1, Norberto Manjarrez, Ernesto Sánchez, Héctor Luna, Alberto López, Myrna Solís

  • Abstract

    In this work were studied the seeds of bayo bean, chickpea, black bean, lima bean, pinto bean, haricot, alberjon, as reductases sources, to perform the reduction of eleven aromatic aldehydes (benzaldehyde (1a), 2-fluorobenzaldehydo (1b), 4-fluorobenzaldehydo (1c), 2-bromobenzaldehydo (1d), 2-chlorobenzaldehydo (1e), 4-chlorobenzaldehydo (1f), 4-metylbenzaldehydo (1g), 4-methoxybenzaldehydo (1h), 3-bromobenzaldehydo (1i), 3-chlorobenzaldehydo (1j), 2-metylbenzaldehydo (1k)). The best results were obtained with lima beans, pinto beans and alberjon, they reduced eight aldehydes with % of conversion higher than 50%. All the seeds reduced 1b, 1c and 1f in more than 80%. Most of the seeds reduced aldehydes 1i, 1j and 1k in low extent, except in the following cases: the reduction 1i with chickpea was 52% and with haricot was 81%, reduction of 1j with chickpea was 80%, whereas the reduction of 1k with lima beans was 88% and with alberjon was 72%. The different seeds used in this study, showed a very high versatility to reduce different substrates; so we can have different sources of alcohol dehydrogenases that can perform specific transformations.


Growth and Lipids Production with Chlorela vulgaris, Scenedesmus sp. and Chlorococum humicola in 1L Bottles, Baffled and Non-Baffled Flasks

Aldo Pérez, Luis C Fernandez, Luis G. Torres 

  • Abstract

    The growth and lipid production of Chlorella vulgaris, Scenedesmus sp and Chlorococcum humicola in 1L bottles, baffled and non-baffled flasks is presented here to determine the best culture system at laboratory scale. The highest optical densities were observed in baffled flasks in comparison with growth observed in bottles and no-baffled flasks, which were very similar, except in the case of C. humicola growths. Regarding the lipids production, it was noted that the highest production was achieved in C. vulgaris, followed by Scenedesmus sp and at the end by C. humicola. For the first and third cases, these productions were achieved in bottles (0.649 and 0.241 g lipid / L culture respectively). In the case of Scenedesmus sp best production was observed in non-baffled flasks (0.323 g lipid / L culture). We discuss the best growth achieved in baffled flasks in comparison with non-baffled flasks and bottles and we associate it with the increase in the levels of oxygenation and mixing.


Glucoamylase Expression in Aspergillus oryzae in Solid-State and Submerged Fermentation

Melissa Vázquez Hernández, Juan Campos Guillen, Andrés Hernández Cruz, Sergio de Jesús Romero Gómez 

  • Abstract

    Aspergillus oryzae is a mold widely used for hydrolases due its high secretion capacity and its GRAS status. It has been reported that Solid-State Fermentation (SSF) is a good alternative to Submerged Fermentation (SmF) as higher production and differential expression of glucoamylase are obtained. In this work we compared glucoamylase production using two different synthetic media in SmF and SSF in Polyurethane Foam (PUF) as a model substrate in order to develop a model system of SSF. When Czapeck-Dox media was used in SmF and SSF glucoamylase production was very similar with a final production at 72 hours of 56 and 62 IUml-1 respectively, when YPS media was used SSF highest glucoamylase production was 51 IU/ml at 48 hours while SmF production was 54 IUml-1 at 72 hours. While in both cases the use of SSF resulted in higher glucoamylase productivity than Smf, increases are marginal, and glucoamylase production is much lower than reported for SSF on natural substrates, this indicate that both support and culture media have an effect on glucoamylase production by A. oryzae, and even when PUF seems to be a suitable support, different growth conditions need to be assayed in order to get a model system of SSF.


Extraction of Caffeic Acid from Residual Coffee Pulpe

Karla A. Valdés, Roger M. Sales, Gabriel Ríos, Minerva Rosas, Ada M. Ríos

  • Abstract

    Coffee pulp is the main solid waste obtained from the wet processing of coffee, as it constitutes approximately 41% of the wet weight of the coffee cherry. Coffee pulp is highly enriched with carbohydrates, protein, and minerals, as well as measurable amounts of tannins, polyphenols, caffeine, and caffeic acid. The widespread use of caffeic acid ranges from drink additives, cosmetics, and tea products, to medical applications, as a result of its antibacterial, antiviral, antioxidant, and anticancer properties. In addition, caffeic acid is used as a precursor in the synthesis of drugs for the treatment of HIV. In this study, the two methods employed for caffeic acid extraction were leaching (A), and a pre-treatment with ultrasound (B), In (A) this method, the extraction was carried out using dried pulp, which was heated on a stove at 70°C for 24 hours. Afterwards, 10 grams of dried pulp were leached using an ethanol solution (50/50) at 60°C for 1 hour. was filtered and concentrated under vaccum. The presence of caffeic acid was determined via Thin Layer Chromatography (TLC; Similar to the method above, 10 grams of dried pulp were placed in a flask containing an ethanol solution, which was then sonicated for 6 hours in an ultrasonic waterbath. The subsequent steps were carried out as in (A). The use of ultrasound in method (B) helped improve the extraction of caffeic acid via leaching, as this method increased the final yield 3-fold. Finally, it was observed that heating the pulp caused its color to become darker, which may have a negative impact on the extraction procedure


Evaluation of Vinasse Derived From the Ethanol Manufacture as Substrate for Production of Useful Microorganisms

Claudia J. Hernández-Guerrero, Diana R. Barajas-Sandoval, R. Noemí Aguila-Ramírez, Francisco Javier Vergara-Camarena, Sergio F. Martínez-Díaz

  • Abstract

    During the distillation of ethanol, vinasse is the main byproduct reaching about 90% of the volume of fermentation, and their final disposal is a serious environmental problem. The aim of this study was to evaluate the vinasse as a substrate to produce different strains of probiotics for aquaculture and biomass of Bacillus thuringiensis and Spirulina maxima. Culture media formulated with 25, 50, 75 and 100% of vinasse, alone and supplemented with molasses were utilized to cultivate bacteria. Spirulina was cultured in Jourdan medium supplement with 5, 10 and 20% of vinasse. All experiments were carried out by triplicate. The optimal conditions to produce bacteria were at 25% and 50% of vinasse. The yield of B. thuringensis at 24 h was similar in media supplemented with vinasse to commercial medium (TSA). The media supplemented with vinasse allows a better development of Spirulina, than the typical Jourdan medium. The results obtained in this study support the idea that it is feasible to use waste from the alcoholic fermentation for the production of useful microorganisms.


Techno-Economical Analysis of a Lignocellulosic Residue Biorefinery and the Importance of High Value Products

Magdalena Amézquita, M.C. Lorena Pedraza

  • Abstract

    A lignocellulosic residue biorefinery case was studied to determine an economically viable model to produce high and low value products that can satisfy the market need for the low value product (biofuels). By fermentation, the biorefinery will produce omega 3 fatty acids, aromas and bioethanol from glucose, as well as xylitol and bioethanol from xylose. An income simulation of the biorefinery using different assignation of the glucose and xylose produced from corncob allowed to determine the most profitable model. By assigning 15% of the glucose and 20% of the xylose to the production of high valued products, it is possible to increase the income of the biorefinery by 173%. Further work is needed in order to calculate not only the income, but also the profit of the biorefinery.


Pectinase Activity Of Pleurotus ostreatus Grown In Solid-State Fermentation

Morales Huerta E., Cruz Chilado M.M.2, Díaz Godínez G.

  • Abstract

    Pectinases are of great importance in the food industry, mainly in obtaining and clarification of juices, wines and beer. In this work, the pectinase activity produced by Pleurotus ostreatus, grown in solid-state fermentation (SSF) on polyurethane foam (PUF) was studied. SSF was performed in 125 ml Erlenmeyer flasks with 0.5 g cubes of PUF (0.5 cm per side), impregnated with 15 ml of culture medium at pH 6.5. The flasks were inoculated with three mycelium plugs of Pleurotus ostreatus of 4 mm diameter. All flasks were incubated at 25°C and 120 rpm for 24 days. Samples were taken every 24 h. Pectinase activity was evaluated by the method of DNS using polygalacturonic acid as substrate. Zymograms were performed using polyacrylamide gels at 10% and 1% pectin, the gel was incubated in acetate buffer pH 4.5 at room temperature, and stained with a ruthenium red solution (0.03%). The maximum pectinase activity was observed at 168 h (exponential growth phase). Three pectinase isoforms were observed through zymogram. Pleurotus ostreatus could be considered as an excellent candidate for the production of these enzymes for industrial use. These results contribute to physiological and biochemical knowledge of Pleurotus ostreatus and management of pectinase production conditions.


Fermentation Kinetics of Saccharomyces cerevisiae in batch and Fed-batch Cultures

Jonathan Guerrero Reyes, María Leticia Ramírez Castillo, Aldo Hernández Díaz, Lucila

Valdez Castro

  • Abstract

    The research to obtain ethanol has increased with the energy and environmental crisis. Nowadays the bioethanol fuel can be produced by fermentation using sugars obtained by hydrolysis of organic solid waste from urban and agricultural sources. However, to enhance its production by fermentation is not enough to control operation variables or optimize the culture medium also depends of the culture type. In this work were studied the kinetics of Saccharomyces cerevisiae in batch and fed batch cultures. The fermentations were carried out in a 4 L fermenter and in the fedbatch culture the volumetric feed rate of concentrated sucrose solution of 150 g.L-1 was set constant. This culture operation mode increased the bioethanol production, two stages were observed, favouring in the first (batch culture) cell growth and in the second (fed-batch culture) the bioethanol production. In batch culture were obtained a maximum specific growth rate of μmax= 0.509 h-1, maximum biomass of 8 g.L-1 and biomass yield of YXS= 0.3 gX.gS -1, without significant ethanol production. Simulations showed a better fit with the Logistic Model. In fed batch culture the final ethanol  oncentration was 25 g.L-1. This strategy can be used to improve the production of other metabolites with similar behaviour.


Study Comparison of Production Performance Conidia of Metarhizium anisopliae in Bioreactors Bag and Packed Column

Fernando Méndez , Ernesto Favela  and Octavio Loera

  • Abstract

    In this study the production of conidia of the entomopathogenic fungus Metarhizium anisopliae in two types of bioreactors solid fermentation was compared: Bag bioreactor (traditional culture) and column bioreactor. Both bioreactors were packed with rice grains at 30% initial moisture, inoculated with 2x106 conidia per gram of dry rice (gdm) and kept at 27 ° C for 11 days. The column bioreactor was aerated at 0.1 mL / gdm. They were measured at 7, 9 and 11 days of fermentation conidial production, viability, moisture in the soil and water activity. After 7 days of fermentation on conidia production bioreactor column 14.79x108 conidia / gdm with 60.11% viability and bioreactor bag 4.93x108 conidia / gdm with 49.78% viability was obtained. Soil moisture and water activity presents average values of 32.4% and 0.996 in both bioreactors. At 9 and 11 days of  ermentation conidia production and viability were statistically equal. The column bioreactor can be used for high scale conidia production since conidia production yield and viability are higher in this bioreactor than the obtained in plastic bags.


Obtaining a Peptide of an Exposed Region of the Tepary BeanLectin (Phaseolus acutifolius) by Molecular Modeling

Emiliano Moreno Salgado, S.M. Ahumada-Solórzano, J.L. Castro-Guillen, I.A. Flores-Ureña, B.P. Martínez-Lugo, A.I. Zapata-Jiménez, E. González-Ortiz, K.G. Rosas-Vega,J.J. Mosqueda-Gualito, A. Blanco-Labra, T. García-Gasca

  • Abstract

    Tepary bean (Phaseolus acutifolius) lectins have showed in vitro and in vivo effects against colon cancer, primarily as an apoptosis inducer. To carry out pharmacokinetic studies is necessary to detect the presence of lectins using immunodetection techniques. The aim of this study was to design a peptide by molecular modeling from an exposed area of the lectin and generate a specific antibody through the synthesized peptide. Bioinformatic programs such as Sequencestructure homology FUGUE Recognition, Comparative JIGSAW- 3D-modeling, CPHmodels 3.2 Server, ESyPred3D Web Server 1.0 and Geno3D were used in order to analyze and identify exposed areas and to discard areas of interaction with other subunits. Subsequently, the exposed site sequences were obtained and aligned using a previous deduced sequence by Mirkov et al. (1994) and the sequence previously obtained by mass spectrometry. Using the program Pymol, the amino acid sequence with low probability of glycosylation was visualized, which consists of a nearby metal binding domain loop. Peptide synthesis will allow the generation of a Tepary bean lectin specific antibody that can be used for biological research. 


Three Carbon Sources for the Production of Polyhydroxyalcanoates (PHAs) by The Native Bacillus cereus

M.E. Alemán, E. Martínez H. , G. Rojas, V. Almaguer, U. López, K Arevalo, L.Galán

  • Abstract

    PHA has properties similar to synthetic plastics and are bio-compatible making it a sustainable and environmental-friendly biomaterial. Bacillus cereus PHA-4 was isolated from garden soil in Mexico, inoculated in nutritive broth supplemented with 0.5% w/v of three differents carbon sources in order to study PHA production. The polymer was extracted from the cells using the sodium hypochlorite and chloroform method. Biomass and PHA content were estimated by gravimetric techniques. The production of PHA ranged between 0.0474 – 0.17 g/L. The higher production was observed with sugar as carbon source. Other materials, such as citric acid, glucose, glycerol, succinic acid, valerate, sucrose have been reported to be used by Bacillus sp for PHA production. To date, there are no studies about a Bacillus cereus strain using methanol and sunflower oil as carbon source for PHA production. The FTIR results showed typical bands and signals of polyhydroxybutyrate (1730, 2960, and 1230–1050 cm–1). The native Bacillus cereus PHA-4, can use sugar and alcohols as unique carbon source for PHA production. The isolation and study of new strains capable of utilizing wide range of carbon source is essential for the biomaterials industries.


Development of Molecular Tools for Genetic Manipulation of Aspergillus sp

Laura J. García-Barrera, Sara M. Uribe-Ochoa, Ángel E. Absalón and Diana Cortés- Espinosa

  • Abstract

    Aspergillus is an important genus among the filamentous fungi. Is widely used for basic genetic research and for the production of a range of valuable products. The second is due its potential as expression host for production of heterologous proteins. Among the molecular tools needed for this aim are the selectable transformation markers and the transformation techniques. For the development of antibiotic selection markers genes, the most widely used inhibitors are hygromycin and bleomycin. Less commonly used selective agents are phosphinothricin (which inhibits glutamine synthase causing a rapid accumulation of ammonia) and carboxin (which prevents mitochondrial respiration by inhibiting the activity of mitochondrial ubiquinone reductase or succinate dehydrogenase). Transformation techniques for Aspergillus are complicated because their multicelular morphology and thick chitinous cell walls. Besides the nucleated protoplast method,  lectroporation and biolistic technique has been studied. Here we constructed and proved two vectors with a strong constitutive promoter, one with the bar gene (phosphinothricin) and the other with the cbx gene (carboxin resistance). We also used two transformation methods (electroporation and biolistic) with two different Aspergillus species for later research  n biopharmaceutical drugs, vaccine development or environmental remediation.


Synthesis of biofuels Via Cross-Metathesis Degradation of Waste Industrial Rubber With Microalgae oils.

Selena Gutiérrez, Bertha Olivia Arredondo-Vega, Mikhail A. Tlenkopatchev, Araceli Martínez

  • Abstract

    Biofuels were synthesize via cross-metathesis degradation of the SBR, using microalgae oils as Chain Transfer Agent (CTA) and green solvent; followed by transesterification reaction. The microalgae strains Neochloris oleoabundans (UTEX LB 1186, was adapted to marine water) and Chlorella sp. (freshwater) were grown with continuous aeration, at 23°C (±1°C), pH= 7.7-8.5, light intensity of 3300 luxes and photoperiod 12h. Biomass was harvested by centrifugation. Microalgae oils were obtained by solvent extraction and used it in cross-metathesis degradation of SBR with Rualkylidene and Ru-vinylidene catalysts. Afterwards, in the same reactor, transesterification was carried out. SBR (molecular weight initial Mn=1.3x105; PDI=1.3) was degraded to oligomers at molecular weight Mn=103, and yield above 90% using Ru-alkylidene  atalyst. However, with Ru-vinylidene catalyst, the yield decreased at 60-70%. After that, the oligomers were transesterified with high yield to biofuels with molecular weight Mn=102. Biofuels obtained are a mixture of biodiesel (methyl esters) and diesel (hydrocarbons of low molecular weight), and molecular weight similar at biodiesel obtained only microalgae oils. Other properties similar between the biofuels obtained and the biodiesel are density (g/mL), kinematic viscosity, 25°C (m2/s), Iodine value and cetane number 0.87, 5.21, 96, 50 and 0.85, 5.01, 97, 46;  espectively.