Search

Contextualization: Hydrolases are some of the most used enzymes in different industrial processes and can be obtained from microorganisms such as bacteria and fungi. Filamentous bacteria are a group of microorganisms present in various environments, and many of these species produce extracellular hydrolases catalyzing the decomposition of compounds such as proteins and polysaccharides. The most representative genus is Streptomyces, a bacterial group found in most soils. It synthesizes enzymes of interest and main antibiotics of microbial origin. Knowledge gap: The high soil diversity in the country is an opportunity for the bioprospecting of native microorganisms with enzymatic potential, which can be found in different understudied agroecosystems and their biochemical capacities could be associated with the environmental and nutritional conditions of the sites where they are found. Objective: To verify the presence of filamentous bacteria producers of hydrolytic enzymes with potential industrial application in different soil types and a composting system. Methodology: Samples were taken from a composting system, from the floor of a path in a native forest, from the rhizospheres of a live fence, and hydrangeas, avocado, blackberry, and Cole crops. Filamentous bacteria were isolated based on the colonies with the corresponding morphology. Enzyme activities were determined using the disk diffusion method to quantify the halos of hydrolysis in starch, carboxymethyl cellulose, gelatin, and olive oil mediums. Results and conclusions: 43 isolates of filamentous bacteria were obtained, of which 36, 42, 39, and 30 had amylase, cellulase, gelatinase, and lipase activity, respectively. At least one isolated with some hydrolytic activity was found in all samples. The composting system and the rhizosphere of the live fence were the sites from which more bacterial isolates were obtained with higher activity. It is likely related to characteristics such as humidity and organic matter from the soils from which they were recovered. [ABSTRACT FROM AUTHOR]

Background: The ever-growing awareness of environmental problems has led to the implementing of ecological alternatives in industrial production. Cellulases and hemicellulases are the most widely used enzymes in industry, guaranteeing the efficiency of production, with a reduction in chemicals that pollute the environment. Aim. To select Bacillus spp. strains that produce cellulases, β-mannanases, and xylanases for use in animal feed. Materials and methods: Overall, ten strains were studied in plates with minimum medium supplemented with Beech Xylan, locust vean gum, and carboxymethylcellulose for the production of xylanases, β-mannanases, and endo cellulases, respectively. The plates were incubated at 37 ºC for 24 hours and were coated with 0.5% Congo red solution. The diameter of the hydrolysis area, and that of the colony, were determined to calculate the potency index. Results: All the strains showed the capacity to produce the studied enzymes. As a result, 23.3% of enzymatic activity was considered good. Bacillus subtilis E-44 was the strain with the best enzymatic activity on the three evaluated substrates (3.01 ± 1.18; 3.82 ± 0.31, and 4.22 ± 0.23) for cellulases, β-mannanases, and xylanases, respectively. Conclusions: Bacillus subtilis E-44 was selected as the best cellulase and hemicellulase-producing strain, increasing their possibilities in animal nutrition and the food industry. [ABSTRACT FROM AUTHOR]

The necessity of reducing enzyme production costs and their wide use in several industrial sectors, have increased the interest on agro-industrial wastes valorization as substrates for the obtention of these bioproducts. Given that agricultural wastes are both a source of cellulose and cellulolytic microorganisms, the purpose of this study was the selection of previously isolated cellulolytic bacteria from wastes generated in marketplaces and, the evaluation of media formulated from this waste. 11 bacterial strains were grown in Mandel’s broth for 72 hours evaluating their cellulolytic activity at 30 and 50 ºC. To formulate the culture media, the cellulose, nitrogen and total organic carbon content in corn cob leaves and legume seed pods collected in a marketplace was determined. Three types of media were made using cellulose, sourced from waste, supplemented with peptone, ammonium sulfate and urea: the last three added as Nitrogen source. Medium A was formulated with chopped and dehydrated wastes. Medium B had the same treatment than medium A plus a liquefy step. Medium C was made with un-dehydrated and liquefied waste. From the 5 selected cellulolytic strains, C6M2 was cultured at 37 ºC on each of the three media and the enzyme activity was monitored for 96 hours of fermentation. Cellulase production was achieved in media A and B. Medium A presented higher production (19,82 ± 3,0 U/mL). On the other hand, no cellulolytic activity was evidenced in medium C. The corn cob leaves and legume seed pods, chopped and dehydrated, allow the cellulase production using the bacterium strain C6M2. [ABSTRACT FROM AUTHOR]

Cellulolytic enzymes are used in different industries; many of them are obtained from fungi and bacteria that use agro-industrial waste with a high cellulose content as a substrate. Some fungi of the genera Trichoderma and Aspergillus synthesize cellulases with different mechanisms of action and mixed cultures of these fungi have been proposed as a strategy to improve the hydrolysis of cellulosic materials associated with the production of these enzymes. The objective of this study was to verify the production of cellulases from mixed and pure cultures of native isolates of T. reesei and A. fumigatus with cellulolytic activity using rice husks as a substrate. Both fungi produce enzymes that catalyze the release of reducing sugars from carboxymethylcellulose. Solid state fermentation was carried out following a factorial design and the effect of the type of inoculum and incubation time on the cellulolytic activity of the extracts obtained was analyzed. Cellulases production after 15 days of incubation was higher than that obtained with 8 days of culture and it was confirmed through an analysis of variance that the cellulases production for the mixed and pure cultures of T. reesei on day 15 (34.5 and 31.9 U/g, respectively) did not present significant differences. It was shown in this work that rice husks have the potential to be used to obtain fungal enzymes, although the activity of enzymes obtained using this byproduct is lower than that produced with other cellulosic materials. [ABSTRACT FROM AUTHOR]

Copyright of Revista Colombiana de Biotecnología is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Ruminants consume pasture and forages, but occasionally they do not have the necessary capacity for this, affecting digestibility. One of the strategies to improve quality is the utilization of exogenous enzymes that break down the structure of the cell wall, and permit better nutrient intake. Aim. To conduct a comprehensive study on the action mechanisms of exogenous fibrolytic enzymes in ruminant nutrition. Development: Plant cell wall is made of cellulose, hemicellulose, and lignin. The cellulases, hemicellulases, and lignocellulolytic enzymes are engaged in their degradation, being used satisfactorily in the diet to enhance digestibility with positive effects on other species’ production. Conclusions: This practice favors greater nutrient availability for digestion and absorption, and it contributes to the improvement of physiological processes, and on many occasions, it is evidenced through livestock yield increases. [ABSTRACT FROM AUTHOR]

Copyright of Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales is the property of Academia Colombiana de Ciencias Exactas, Fisicas y Naturales and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Colombiana de Investigaciones Agroindustriales is the property of Revista Colombiana de Investigaciones Agroindustriales del Centro Agropecuario Sena Buga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The present study aimed to optimize the enzymatic hydrolysis process to degrade cellulose from corn stubble (Zea mays), using enzymes from Aspergillus niger. During the first phase of the experimentation, the content of dry matter, organic matter, ash, crude protein, ethereal extract, lignin and cellulose content of the stubble was determined, using the reference methods of the U. Florida 1970 for its quantification. Subsequently the pre-drying and grinding of the same was carried out, prior to the alkali and acid-alkali pre-treatment processes applied, being dried at 4 different temperatures (45, 50, 55 and 60 ®C). The pretreated residues were subjected to hydrolysis with Aspergillus Niger cellulases (39,125 EU) at different pHs (4.0, 4.8 and 5.6), for 24, 48 and 72 h. at 45, 50, 55 and 60 ®C temperature; quantifying the concentrations of reducing sugars released during digestion. Finally, it was determined that the hydrolysis of the stubble without pretreatment and drying at 60 ®C, at a pH of 4.8 for 72 h., had high concentrations of reducing sugars, becoming an alternative for its use as food or biofuel, after the application of biotechnological processes. [ABSTRACT FROM AUTHOR]

Plant Growth Promoting Rhizobacteria constitute a promising source of microorganisms, with the capacity to develop new biopesticides that contribute to pest control, with an agroecological and sustainable basis. The objective of this work was to obtain isolates of endospore-forming bacilli with biotechnological potential from the rhizosphere of different cultivars of bean (Phaseolus vulgaris L.) from three types of soil. Rhizospheric soil collections were made from three bean cultivars present in the municipalities of Colón and Unión de Reyes, in the province of Matanzas, Cuba. The soil samples were grown in Nutrient Broth and the vegetative cells were subsequently removed with heat. Serial dilutions were made and the samples were inoculated in Nutrient Agar culture medium. Bacterial colonies with morphological differences and Gram-positive and endospore-producing bacterial cells were selected. The antagonistic potentialities of the isolates were evaluated through the production of lytic enzymes such as proteases, lipases, cellulases, amylases, chitinases and / or ß-glucanases and the synthesis of hydrogen cyanide. A collection of 141 isolates of endospore-forming Gram positive bacilli was made. The 8% of isolates were producers of hydrogen cyanide, 57.7% of proteases, 19.3% of lipases, 56.5% of chitinases and / or ß-glucanases, 28.5% of cellulases and 33.3% of α-amylases. These isolates have biotechnological potential with application in the agricultural and industrial sectors. [ABSTRACT FROM AUTHOR]

Neem seed (Azadirachta indica) contains triterpenoids with acaricidal and pest repellent activity in the agricultural sector. The concentration of the compounds in neem oil depends on the method of extraction. The hypothesis in this study was that the use of enzymes and solvents increases the release of Azadirachtin A (AzaA) from the neem seed, and its concentration remains stable in the extracts during storage at different temperatures. The objective was to determine the effect of hexane maceration of neem extracts prepared with Crystalzyme® PLMX, Crystalzyme® Cran, Crystalzyme® 100XL, and Cellulase 17600L on the extraction of azadirachtin A (AzaA) and its storage stability. The experimental design was completely randomized with three repetitions. The experimental unit was the neem seed collected from a plantation in Jamapa, Veracruz, Mexico. The loss rate constant (k) of AzaA in storage was determined by a first order equation. Data were analyzed with ANDEVA and the Tukey mean comparison test (p£0.05). The highest concentration of AzaA (2.73 g L-1) was obtained with CPLMX in hydrolysis and 24 h of maceration with hexane, with a greater proportion of the aqueous fraction (2.67 g L-1) than the hexane fraction (0.06 g L-1). The concentrations of AzaA extracted with the use of enzymes and hexane were similar to those obtained by ultrasound, mechanical pressing and methanolic extrusion. The loss of AzaA in the enzyme extracts increased with the increase in storage temperature, since it was not detected in the enzyme extracts after 7 and 28 d of storage at 50 and 30 °C, respectively. The concentration of AzaA (20%) remained constant 28 d after storage at 5 °C and showed the lowest k among the enzyme extracts. [ABSTRACT FROM AUTHOR]

Copyright of Revista de la Sociedad Química del Perú is the property of Sociedad Quimica del Peru and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Determination of optimum temperature in the (PFasa) cellulase production, by a strain of Aspergillus niger in solid fermentationis presented in this paper, using data from a previously proposed kinetic model. Dependence of the 16 kinetic parameters with temperature (in the range of 20 °C to 40 °C), was established. For µmax and xmax parameters, the adjustment was achieved using the Rosso and Ratkowsky models respectively. Cubic interpolation models was needed to adjust the rest of kinetic parameters. The dependence of the kinetic model parameters with temperature allowed the estimation of temperature and optimum fermentation time to maximize the productivity in the production of true protein and the activity of the three studied enzymes. As result, the optimum temperature rangeisbetween 30°C and 32°C. For the production of true protein and CMcasa, the optimum fermentation time is located within the19 and 22 hours respectively, but for the production of PFasa, is 33 hours. The protease activity presented several local maxima in terms of optimal temperatures ranging from 25 to 40 °C. Although the maximum activity levels are 64 UI/gdm, which, according to literature, is an intermediate value, the level of productivity of PFasa is the highest found (3.84 times superior to average activity), when compared with another 20 reports consulted since 2004. [ABSTRACT FROM AUTHOR]

In this work a kinetic model proposal is presented for describing cellulase production in a solid-state fermentation process of an Aspergillus niger strain. The validation of the model was carried out at five temperatures: 20, 25, 30, 35 and 40°C. In the validation the characteristic parameters of the model were identified using a dynamic data generated at constant temperature. The response variables described by the model are: concentration of biomass of fungus measured as true protein, total reducing sugars, crude fiber, FPase activity, CMCase activity and the activity of proteases in the medium. For parameters identification the process model was programmed in MATLAB. The results indicate that the model is perfectly capable describing the cellulase production kinetics under these conditions. The temperatures where cellulase production was higher were 30°C and 35°C. The experimental levels of FPase and CMCase are significant because maxim values of FPase of 60 UI gDW-1 and of CMCase of 50 UI gDW-1 are reached in a fermentation time ranging from 24 to 30 hours. The identified parameters are strongly associated to temperature. [ABSTRACT FROM AUTHOR]

In this work, a kinetic study is presented analyzing the influence of the initial pH on (PFasa) cellulase production by an Aspergillus niger strain, cultured in solid-state fermentation. The results showed that the optimum value of initial pH for PFasa production was 4.5. The PFasa activity reached 25.11 UI/gMS in 18 hours and a productivity of 1.40 UI h-1gMS-1 under these initial pH conditions. [ABSTRACT FROM AUTHOR]

Copyright of Revista Colombiana de Investigaciones Agroindustriales is the property of Revista Colombiana de Investigaciones Agroindustriales del Centro Agropecuario Sena Buga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The present study shows the results of obtaining fermentable sugars using elephant grass (Pennisetum purpureum) feedstock. The concentration effect of acetic acid (CH3COOH) and sodium chlorite (NaClO2) was assessed on the removal of lignin hemicellulose complex. A comparison was made about method, using basic pretreatment with sodium hydroxide (NaOH) and hydrogen peroxide (H2O2). The Saccharification step is carried out by enzymatic hydrolysis method that is performed using cellulase and β-glucosidase. The results show in the case of pretreatment with NaClO2 and CH3COOH a percentage of saccharification of 80.87% compared to NaOH pretreatment with a percentage 56.82% and hydrogen peroxide with a percentage of 44.75%. [ABSTRACT FROM AUTHOR]

In soils, the macro invertebrate-microorganism-biomass interaction is a fundamental axis for carbon cycling. Sugarcane is a major biomass-producing, abundant crop residues are left on the field. These crop residues are frequently burned before harvesting in Colombia. This work studied the sugar cane residues transformation by scarab larvae and microorganisms interactions, taking account of the β-glucosidase activity. The crop residues consumption by population assemblages of three Dynastinae scarab species was evaluated. Significative differences in β-glucosidase activity were found between the population assemblages and respecting the control treatment. It was shown that precisely two Oryctini (Coleoptera: Scarabaeoidea) species, historically regarded as pests, are the ones which through their synergic interaction with the edaphic microbiota, led to high β-glucosidase levels in soils. Results indicate that the rhinoceros beetle Podischnus agenor Oliver is the major litter consumer and positively contributes to sugar cane crops, as far as its feeding requirements are not restricted by pre-harvest burning. Strategus aloeus Linné, in association with P. agenor displayed a similar behaving. [ABSTRACT FROM AUTHOR]

Copyright of Revista Colombiana de Biotecnología is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of BIOAGRO is the property of Revista BIOAGRO and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim of this work was to identify lignolytic and cellulolytic fungal strains capable of degrading harvest waste and thereby improving the soil characteristics of the eastern Llanos of Colombia. Sampling was carried out using the transept methodology and integrated samples. A lignolytic strain (005L Verticillium spp.) and 72 cellulolytic strains were obtained. A comparison of soil usages (savanna grazing and secondary forest) showed no correlation between the number of obtained genera and soil characteristics. Selection of the strains to be evaluated in a dry-grass natural substrate (Brachiaria spp.) was carried out by quantification of lignolytic and cellulolytic activity. Two strains with high exoglucanase activity (055C and 061C Penicillium spp.) and a strain with high endoglucanase activity (019C Trichoderma spp.) relative to the Trichoderma viride control were selected and evaluated in the natural substrate in consortia formed by one lignolytic and one cellulolytic. The test showed that the enzymatic activity of the selected strains increased in the substrate grass, surpassing that of the positive controls (Pleurotus ostreatus for lignin and T. viride for cellulose) for both consortia. The use of the consortia is therefore recommended for the development of soil conditioning biofertilizers, especially that formed by the 005L (Verticillium spp.) and 055C (Penicillium spp.) strains with high lignolytic and cellulolytic activity. [ABSTRACT FROM AUTHOR]

Copyright of Revista Colombiana de Biotecnología is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Coffee pulp is one of the polluting solid residuals of the coffee industry, it constitutes 40 % of the weight of the fruit. In the work reported here three sources of inoculum were assayed (bovine manure, supernatant and sedimenting muds coming from humid benefic center), for the anaerobic degradation of pulp of the variety Coffea arabic L. in a bioreactor carrying out a batch fermentation. The influence of each inoculum on methane production and cellulolytic enzymatic activity was tested. The bovine manure without heat treatment showed the biggest value of methane production, relative methanogenic activities and total cellulase activity, this value was 10,29 L; 0,004 mL CH4/ g SV * d and 0,2637 m moles.min-1mL-1 respectively. The results suggested that bovine manure was the most advisable inoculum for the starting of digestors that use the coffee pulp as substrate. [ABSTRACT FROM AUTHOR]

El artículo considera una investigación sobre el uso de celulasa en el tratamiento de fitobezoares, una condición gastrointestinal que consiste en la indigestión de material vegetal. Los autores analizan las causas de la condición, incluyendo masticación insuficiente, hiperclorhidria y antecedentes de cirugía gastrointestinal. Se enfatiza la importancia de más estudios sobre la eficaz de la celulasa en el tratamiento esta enfermedad.