Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 20
Filter
1.
Electron. j. biotechnol ; 48: 29-35, nov. 2020. ilus, tab, graf
Article in English | LILACS | ID: biblio-1254696

ABSTRACT

BACKGROUND: Cellulose as a potential feed resource hinders its utilization because of its complex structure, and cellulase is the key to its biological effective utilization. Animal endogenous probiotics are more susceptible to colonization in the intestinal tract, and their digestive enzymes are more conducive to the digestion and absorption of feed in young animals. Min pigs are potential sources of cellulase probiotics because of the high proportion of dietary fiber in their feed. In this study, the cellulolytic bacteria in the feces of Min pigs were isolated and screened. The characteristics of enzymes and cellulase production were studied, which provided a theoretical basis for the rational utilization of cellulase and high-fiber food in animal production. RESULTS: In our study, 10 strains of cellulase producing strains were isolated from Min pig manure, among which the M2 strain had the best enzyme producing ability and was identified as Bacillus velezensis. The optimum production conditions of cellulase from strain M2 were: 2% inoculum, the temperature of 35°C, the pH of 5.0, and the liquid loading volume of 50 mL. The optimum temperature, pH and time for the reaction of cellulase produced by strain M2 were 55°C, 4.5 and 5 min, respectively. CONCLUSIONS: Min pigs can be used as a source of cellulase producing strains. The M2 strain isolated from feces was identified as Bacillus velezensis. The cellulase from M2 strain had a good activity and the potential to be used as feed additive for piglets.


Subject(s)
Animals , Swine, Miniature , Bacteria/enzymology , Cellulase/biosynthesis , Bacillus , Dietary Fiber , Probiotics , Digestion , Feces , Animal Feed
2.
Braz. arch. biol. technol ; 63: e20190185, 2020. tab, graf
Article in English | LILACS | ID: biblio-1132193

ABSTRACT

Abstract The second-generation bioethanol employs lignocellulosic materials degraded by microbial cellulases in their production. The fungus Trichoderma reesei is one of the main microorganisms producing cellulases, and its genetic modification can lead to the optimization in obtaining hydrolytic enzymes. This work carried out the deletion of the sequence that encodes the zinc finger motif of the transcription factor ACE1 (cellulase expression repressor I) of the fungus T. reesei RUT-C30. The transformation of the RUT-C30 lineage was confirmed by amplification of the 989 bp fragment relative to the selection marker, and by the absence of the zinc finger region amplification in mutants, named T. reesei RUT-C30Δzface1. The production of cellulases by mutants was compared to RUT-C30 and measured with substrates carboxymethylcellulose (CMC), microcrystalline cellulose (Avicel®) and Whatman filter paper (PF). The results demonstrated that RUT-C30Δzface1 has cellulolytic activity increased 3.2-fold in Avicel and 2.1-fold in CMC and PF. The mutants presented 1.4-fold higher sugar released in the hydrolysis of the biomass assays. These results suggest that the partial deletion of ace1 gene is an important strategy in achieving bioethanol production on an industrial scale at a competitive price in the fuel market.


Subject(s)
Trichoderma/enzymology , Cellulase/biosynthesis , Zinc Fingers , Biomass , Ethanol , Biofuels
3.
Electron. j. biotechnol ; 31: 84-92, Jan. 2018. graf, tab, ilus
Article in English | LILACS | ID: biblio-1022139

ABSTRACT

Background: Cellulolytic enzymes of microbial origin have great industrial importance because of their wide application in various industrial sectors. Fungi are considered the most efficient producers of these enzymes. Bioprospecting survey to identify fungal sources of biomass-hydrolyzing enzymes from a high-diversity environment is an important approach to discover interesting strains for bioprocess uses. In this study, we evaluated the production of endoglucanase (CMCase) and ß-glucosidase, enzymes from the lignocellulolytic complex, produced by a native fungus. Penicillium sp. LMI01 was isolated from decaying plant material in the Amazon region, and its performance was compared with that of the standard isolate Trichoderma reesei QM9414 under submerged fermentation conditions. Results: The effectiveness of LMI01 was similar to that of QM9414 in volumetric enzyme activity (U/mL); however, the specific enzyme activity (U/mg) of the former was higher, corresponding to 24.170 U/mg of CMCase and 1.345 U/mg of ß-glucosidase. The enzymes produced by LMI01 had the following physicochemical properties: CMCase activity was optimal at pH 4.2 and the ß-glucosidase activity was optimal at pH 6.0. Both CMCase and ß-glucosidase had an optimum temperature at 60°C and were thermostable between 50 and 60°C. The electrophoretic profile of the proteins secreted by LMI01 indicated that this isolate produced at least two enzymes with CMCase activity, with approximate molecular masses of 50 and 35 kDa, and ß-glucosidases with molecular masses between 70 and 100 kDa. Conclusions: The effectiveness and characteristics of these enzymes indicate that LMI01 can be an alternative for the hydrolysis of lignocellulosic materials and should be tested in commercial formulations.


Subject(s)
Penicillium/enzymology , Cellulase/biosynthesis , beta-Glucosidase/biosynthesis , Oligosaccharides , Temperature , Trichoderma/enzymology , Enzyme Stability , Cellulase/metabolism , beta-Glucosidase/metabolism , Amazonian Ecosystem , Biocatalysis , Fermentation , Hydrogen-Ion Concentration , Hydrolysis , Lignin/metabolism
4.
An. acad. bras. ciênc ; 89(3,supl): 2359-2370, 2017. tab, graf
Article in English | LILACS | ID: biblio-886801

ABSTRACT

ABSTRACT During composting processes, the degradation of organic waste is accomplished and driven by a succession of microbial populations exhibiting a broad range of functional competencies. A total of 183 bacteria, isolated from a composting process, were evaluated for cellulase activity at different temperatures (37, 50, 60, and 70°C) and pH values. Out of the 22 isolates that showed activity, isolate 380 showed the highest cellulase activity. Its ability to produce cellulase was evaluated in culture medium supplemented with carboxymethyl cellulose, microcrystalline cellulose, wheat straw, and rice husk. The culture medium supplemented with carboxymethyl cellulose induced higher enzyme activity after 6 hours of incubation (0.12 UEA mL-1 min-1). For wheat straw and rice husk, the results were 0.08 UEA mL-1 min-1 for both, while for microcrystalline cellulose, 0.04 UEA mL-1 min-1 were observed. The highest carboxymethyl cellulase activity was observed at 60°C (0.14 UEA mL-1 min-1) for both crude and partially purified enzyme after 30 and 120 min of incubation, respectively. Alkalinization of the medium was observed during cultivation in all substrates. The cellulase had a molecular mass of 20 kDa determined by SDS-Page. Isolate 380 was identified as Bacillus licheniformis. This work provides a basis for further studies on composting optimization.


Subject(s)
Carboxymethylcellulose Sodium/pharmacology , Cellulase/isolation & purification , Cellulase/biosynthesis , Culture Media/pharmacology , Bacillus licheniformis/enzymology , Substrate Specificity , Electrophoresis, Polyacrylamide Gel , Bacillus licheniformis/drug effects , Hot Temperature
5.
Electron. j. biotechnol ; 19(1): 23-28, Jan. 2016. ilus
Article in English | LILACS | ID: lil-781166

ABSTRACT

Background: Lignocellulosic biomass is a renewable, abundant, and inexpensive resource for biorefining process to produce biofuel and valuable chemicals. To make the process become feasible, it requires the use of both efficient pretreatment and hydrolysis enzymes to generate fermentable sugars. Ionic liquid (IL) pretreatment has been demonstrated to be a promising method to enhance the saccharification of biomass by cellulase enzyme; however, the remaining IL in the hydrolysis buffer strongly inhibits the function of cellulase. This study aimed to isolate a potential IL-tolerant cellulase producing bacterium to be applied in biorefining process. Result: One Bacillus sp., MSL2 strain, obtained from rice paddy field soil was isolated based on screening of cellulase assay. Its cellulase enzyme was purified and fractionated using a size exclusion chromatography. The molecular weight of purified cellulose was 48 kDa as revealed by SDS-PAGE and zymogram analysis. In the presence of the IL, 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]) concentration of 1 M, the cellulase activity retained 77.7% of non-IL condition. In addition, the optimum temperature and pH of the enzyme is 50°C and pH 6.0, respectively. However, this cellulase retained its activity more than 90% at 55°C, and pH 4.0. Kinetic analysis of purified enzyme showed that the Km and Vmax were 0.8 mg/mL and 1000 μM/min, respectively. Conclusion: The characterization of cellulase produced from MSL2 strain was described here. These properties of cellulase made this bacterial strain become potential to be used in the biorefining process.


Subject(s)
Bacillus/enzymology , Cellulase/isolation & purification , Cellulase/biosynthesis , Oryza , Soil Microbiology , Temperature , Bacillus/metabolism , Biomass , Ionic Liquids , Biofuels , Hydrogen-Ion Concentration , Hydrolysis , Lignin
6.
Article in English | IMSEAR | ID: sea-163028

ABSTRACT

Aim: To isolate and identify the potential extremophilic cellulase producing strain viz., psychrophiles, halophiles, thermophiles and to compare the Cellulase activity from samples collected from different geographical regions of India. Place and Duration of Study: Bharathiar University, Department of Biotechnology, Molecular Microbiology Lab, Coimbatore, Tamilnadu, India, between January to April 2011. Methodology: Cellulase-producing extremophilic bacteria viz., psychrophiles, halophiles, and thermophiles have been isolated from soil samples. According to morphology and pigmentation, 138 distinct bacteria were isolated and screened for cellulase activity by Gram’s iodine–carboxymethylcellulose plate (CMC) assay. On the basis of the cellulase activity, six potent cellulase-producing isolates from each cluster viz., P14, P36, H6, H13, T2 and T3 were selected for 16S rRNA gene based identification. The strains were optimized for maximum cellulase activity at various temperature and pH range. Results: The phylogenetic relationship revealed that P14 and P36 psychrophilic isolates possessed maximum identity with Bacillus simplex (100%) and Arthrobactercitreus (99%), with a cellulase activity of 14.10± 1.73 and 18.27± 0.71 UmL-1 respectively. Likewise, among halophiles, H6 and H13 were identified as Bacillus subtilis and Bacillus endophyticus (99%), with a cellulase activity of 14.87 ± 0.55 and 16.83 ± 0.44 U mL-1, correspondingly. In thermophiles, T2 and T3 showed close proximity with Bacillus amyloliquefaciens and Bacillus megaterium (99%), with a cellulase activity of 21.53 ± 1.30 and 19.93 ± 0.38 U mL-1 respectively. Conclusion: In the present study, the thermophilic isolates showed promising Cellulase activity compared to psychrophiles and halophiles.


Subject(s)
Bacteria/isolation & purification , Bacteria/metabolism , Biological Assay/methods , Cellulase/analysis , Cellulase/biosynthesis , India , RNA, Ribosomal, 16S , Soil/microbiology , Soil Microbiology
7.
Rev. colomb. biotecnol ; 12(2): 139-150, dic. 2010. ilus, graf, tab
Article in Spanish | LILACS | ID: lil-590780

ABSTRACT

Existe un gran interés por el uso de enzimas lignocelulolíticas en varias industrias, y en la biodegradación de biomasa para la producción de biocombustibles y otras aplicaciones. Entre las fuentes microbianas de enzimas, Aspergillus niger es uno de los microorganismos más utilizados en la producción de enzimas industriales, debido a sus niveles altos de secreción de proteína y a su condición GRAS (generally regarded as safe). El objetivo del presente estudio fue evaluar la influencia de la concentración de inóculo en la morfología y producción de celulasas y xilanasas con A. niger en cultivo sumergido. Para ello, fueron inoculados matraces de 250 mL con 40 mL de medio con 3% (v/v) de una suspensión de 104 o 108 esporas por mililitro e incubados a 28 ºC y 175 rpm durante 120 horas. Se utilizaron 10 g*L-1 de lactosa como fuente de carbono. En cada caso se determinó la cantidad de biomasa, la proteína extracelular soluble, lactosa residual, actividad celulasa total y xilanasa cada 24 horas. Aunque no hubo un efecto notorio en la morfología de crecimiento, salvo en el color y el diámetro de pellets obtenidos, sí se afectó la µmax (0,06 y 0,03 h-1 para 104 y 108 esporas*mL-1, respectivamente) y la concentración máxima de biomasa. Además, mientras que las productividades volumétricas de celulasa (ΓFPA) (8,2 y 8,0 UI.*L-1*h-1 para 104 y 108 esporas*mL-1, respectivamente) fueron similares para ambos inóculos, la productividad de xilanasa (ΓXIL) fue mayor para el inóculo más concentrado (29,7 y 33,4 UI¨*L-1*h-1 para 104 y 108 esporas*mL-1, respectivamente). Los resultados indican que la productividad de celulasas y xilanasas está estrechamente relacionada con la concentración de inóculo.


There is a great interest for the use of lignocellulolytic enzymes in several industries and in biomass degradation for production of biofuels and other applications. Among the microbial sources of enzymes, Aspergillus niger is one of the most used microorganisms in the production of industrial enzymes due to its high levels of protein secretion and its GRAS (generally regarded as safe) condition. The aim of the present study was to evaluate the influence of A. niger inoculum concentration in the morphology and production of cellulases and xylanases in submerged cultures. For this, 250 mL flasks containing 40 mL culture medium were inoculated with a 3% (v/v) of either 104 or 108 spores per milliliter suspension and incubated at 28 º C and 175 rpm during 120 hours. Lactose (10 g*L-1) was used as the carbon source. In each case, the amount of biomass, the extracellular soluble protein, residual lactose, total celullase activity and xylanase activity were determined every 24 hours. Even thought there was not a notorious effect on the growth morphology, except in color and diameter of pellets; µmax was affected (0.06 and 0.03 h-1 for 104 and 108 spores*mL-1, respectively) as well as maximum biomass concentration. In addition, while the volumetric productivity of cellulase (8.2 and 8.0 UI*L-1*h-1 for 104 and 108 spores*mL-1, respectively) were similar for both inocula, the productivity of xylanase was greater for the more concentrated inoculum (29.7 and 33.4 UI*L-1*h-1 for 104 and 108 spores*mL-1, respectively).The results show that cellulase and xylanase productivities are closely related to the inoculum concentration.


Subject(s)
Cellulase/analysis , Cellulase/biosynthesis , Cellulase/genetics , Cellulase/immunology , Cellulase/chemistry , Cellulase/chemical synthesis , Aspergillus niger/enzymology , Aspergillus niger/physiology , Aspergillus niger/genetics , Aspergillus niger/immunology , Aspergillus niger/chemistry
8.
Electron. j. biotechnol ; 9(1)Jan. 2006.
Article in English | LILACS | ID: lil-432459

ABSTRACT

Mutant strains from Aspergillus niger UAM-GS1 were produced by UV radiation to increase their hemicellulolytic and cellulolytic activity production. The mutant strains showing more enzymatic activity were those labelled GS1-S059 and GS1-S067. These strains also showed the largest relationship between diameter of hydrolysis zone and colony diameter. The mutant GS1-S067 showed a colony radial extension rate and a biomass growth rate g biomass/(cm² h), 1.17 times higher than that achieved by strain UAM-GS1. The high invasive capacity makes this mutant strain a promising alternative for its use in solid substrate fermentation (SSF). The morphological properties of the two mutant strains were evaluated by using scanning electron microscopy. The diameter of the sporangium of the mutant strains GS1-S059 and GS1-S067 was significantly larger (P < 0.05) than that found for the parental strain. The hypha length and diameter of the mutant strains significantly changed (P < 0.05) compared to the parental strain. A Pearson correlation analysis on hypha length, sporangium diameter, and cellulase and xylanase activities indicated that there was a strong relationship among these variables in relation to mannanase activity. Mutant strains GS1-S059 and GS1-S067 significantly increased their level of mannanase, xylanase and cellulase production, compared to the parental strain, improving their potential industrial applications.


Subject(s)
Aspergillus niger/enzymology , Aspergillus niger/genetics , beta-Mannosidase/biosynthesis , Aspergillus niger/growth & development , Aspergillus niger/radiation effects , Aspergillus niger/ultrastructure , Cellulase/biosynthesis , /biosynthesis , Microscopy, Electron, Scanning , Mutation , Ultraviolet Rays , beta-Mannosidase/metabolism
9.
J Environ Biol ; 2003 Apr; 24(2): 173-6
Article in English | IMSEAR | ID: sea-113251

ABSTRACT

Banana a major cash crop of Maharashtra is cultivated over 46900 hectares generating large amount of agro waste after the harvest. Attempts were made to utilize these agro wastes for production of cellulases. Of the 127 fungi isolated from the soil of banana field, 12 fungi were found to utilize cellulose as source of carbon. Trichoderma lignorum showed appreciable cellulolytic activity. It produced Cl, Cx and beta glucosidase in Carboxymethyl Cellulose Peptone medium as well as on agro waste based medium containing leaves, stem and rhizome powders. T. lignorum (0. 45 U/ml) produced maximum enzymes on leaf based medium.


Subject(s)
Agriculture , Cellulase/biosynthesis , Conservation of Natural Resources , Fungi/enzymology , Musa , Refuse Disposal/methods , Soil Microbiology
10.
Medical Journal of Islamic World Academy of Sciences. 1998; 9 (4): 119-124
in English | IMEMR | ID: emr-48786
11.
Bulletin of the Faculty of Science-University of Alexandria. 1996; 36 (1): 139-150
in English | IMEMR | ID: emr-40567

ABSTRACT

The growth and cellulase production by the thermotolerant Aspergillus terreus R-4 grown on filter mud [FM] waste, as the sole carbon source, were optimal when the culture medium was composed of [g/I]: FM, 25; casein, 4; KH[2]PO[4], 2; MgSO[4]. 7H[2]O, 0.5; NaCl, 2. The effect of adding various substrates in presence of FM was examined. The supplementation of glucose [5 g/I] to the fermentation medium stimulated maximal cellulase activity, but higher concentrations of glucose repressed production of cellulases. The optimal conditions for CMCase, FPase and cellobiase were at pH 4.8 and 60°C. The cellulolytic enzymes produced by A-terreus R-4 were stable over a wide range of pH values. Enzyme activity was assayed after exposure to elevated temperatures for 15 min and its thermal stability was determined


Subject(s)
Cellulase/biosynthesis , Aspergillus
12.
Egyptian Journal of Microbiology. 1992; 27 (1): 157-75
in English | IMEMR | ID: emr-23634
13.
Arch. biol. med. exp ; 23(2): 147-9, oct. 1990. ilus
Article in English | LILACS | ID: lil-96786

ABSTRACT

Fed-batch production of cellulases through fermentation of leached sugar beet pulp (LSBP) with Trichoderma aurioviride II, a wild type strain from the south of Chile, is investigated. Cultures run for nine days showing a sustained increase in filter paper, endoglucanase, exoglucanase, and cellobiase activities with maximum values of 0.1, 2.2, 0.35 and 0.74 units/ml, respectively. Fed-batch cultures allow to achieve longer process times as compared to typical batch fermentation


Subject(s)
Cellulase/biosynthesis , Fermentation , Trichoderma/enzymology , Fermentation , Plants
14.
Egyptian Journal of Microbiology. 1990; 25 (3): 389-400
in English | IMEMR | ID: emr-15961

ABSTRACT

Treated corn cobs cellulose [2%] was used as the only carbon source for the growth and production of extracellular cellulases and proteases by four cellulolytic microbes: Penicillium funiculosum, Phanerochaete chrysosporium, Micromonospora calcea and Trichoderma virideTViride and Pfuniculosum showed a great ability for the production of carboxy-methyl cellulase [CMCase], filter paper-ase [FPA], neutral and acid proteasesMaximum neutral protease activity was obtained with MCalcea and TvirideOptimum activities in relation to the incubation periods varied according to the enzyme studied and the organism testedThe effect of different carbon sources on cellulases and proteases production indicates that cellulose and lactose were good inducers for CMCase production by Pfuniculosum and PhChrysosporium respectivelyThe latter inducers were also the best for the production of neutral proteases by Tviride and Mcalcea respectively, while cellobiose and lactose were the best inducers for acid protease production by PFuniculosum and Phchrysosporium, respectively


Subject(s)
Carbon , Cellulase/biosynthesis , Enzyme Induction
15.
Egyptian Journal of Microbiology. 1989; 24 (2): 223-234
in English | IMEMR | ID: emr-12744

ABSTRACT

The present study indicated that maximum production of cellulase was attained on cellobiose and sucrose media either as sole C-sources or mixed with cellulose. Starch and glucose seemed to be inhibitory for enzyme synthesis, although they caused high mycelial growth. Of the different N-sources tested, organic nitrogen [casein and peptone] proved to be stimulatory for enzyme synthesis, although casein caused poor fungal growth. Sodium and potassium ions favoured enzyme synthesis when they were used as nitrate salts, while ammonium nitrate and ammonium chloride were less favourable. Ammonium phosphate in its monobasic and dibasic salts suited cellulase activity and fungal growth than the same salts of sodium and potassium. When microelements were incorporated in culture media cobalt and manganese had stimulatory effects on enzyme synthesis and fungal growth while ferrous ions had inhibitory action. When the fungus was incubated at different temperature levels, the highest concentration of enzyme was observed at 25 degree and maximum cell mass was at 30 degree. Tests for the effect of initial pH proved that at a pH range of 4-5 suitable amounts of the enzyme were formed; optimum growth was reached at pH 6. Experiments on crude enzyme preparations indicated that the best reaction time was 60 min and best reaction temperature was 60 degrees


Subject(s)
Cellulase/biosynthesis
SELECTION OF CITATIONS
SEARCH DETAIL