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1.
Acta sci., Anim. sci ; 41: e45100, jul. 2019. tab, graf
Artigo em Inglês | VETINDEX | ID: vti-21616

RESUMO

The aim of this study was to evaluate the action of commercial and non-commercial cellulase and pectinase on rice husk and Tifton 85 hay hydrolyses. The hydrolysis kinetics of the substrates with commercial cellulase and pectinase were evaluated and the hydrolysis at different temperature and agitation conditions was maximized using experimental design. The combined use of commercial and non-commercial enzymes under optimized conditions was evaluated. The pre-treatment of the residues was also investigated by milling and different concentrations of NaOH. Finally, the effect of the hydrolysis on the bromatological composition of the residues was evaluated. The best hydrolysis times of rice husk and Tifton 85 hay were 10 and 12h for commercial cellulase, 12 and 14h for noncommercial cellulase, 10 and 14h for commercial pectinase and 16 and 20h for non-commercial pectinase, respectively. The highest hydrolysis values were obtained using commercial cellulase with 1:50 (w:v enzyme:water) dilution rate, at 45ºC and 300 rpm agitation for both substrates, reaching 20.6% maximum percentage for Tifton 85 hay and 11.6% for rice husk. The combined use of commercial enzymes did not increase hydrolysis percentage. The pre-treatment using 7.5% NaOH and 0.5 mm grain size significantly increased the rice husk and Tifton 85 hay hydrolyses (60-80%), either using commercial cellulase or pectinase enzymes. The use of non-commercial enzymes provided 18-30% hydrolysis obtained from commercial ones. Bromatological analyzes indicated a reduction in neutral detergent fiber and acid detergent fiber content for rice husk and Tifton 85 hay when using pectinases and commercial cellulases.(AU)


Assuntos
Poligalacturonase/efeitos adversos , Poligalacturonase/análise , Celulase/efeitos adversos , Celulase/análise , Cynodon/enzimologia , Hidrólise
2.
Rev. Bras. Zootec. (Online) ; 48: e20180273, 2019. tab, graf
Artigo em Inglês | VETINDEX | ID: biblio-1510696

RESUMO

This study investigated the effect of transformed Lactobacillys reuteri on intestinal pH and morphology, carcass characteristics, meat quality, and serum biochemical indexes of broiler chickens. A total of 480 broilers were assigned to six treatment groups and fed a phosphorus-adequate diet, a phosphorus-deficient diet, or a phosphorus-deficient diet containing different L. reuteri recombinants. The results showed that transformed L. reuteri decreased the pH in the duodenum and jejunum of chickens at day 21, decreased drip loss and cooking loss of muscles, and improved muscle tenderness of chickens at days 21 and 42, but did not affect carcass characteristics and only slightly decreased abdominal fat. Transformed L. reuteri also significantly increased calcium, phosphorus, and glucose levels, decreased the uric acid level of serum at day 21, and significantly increased the glucose level and decreased the triglycerides of serum on day 42. L. reuteri pLEM4159-cel/phy increased the villi height in the duodenum of chickens at days 21 and 42. The transformed L. reuteri decreased the crypt depth in the duodenum and jejunum of chickens at day 21 and also decreased the crypt depth in the ileum and increased the villi height in the duodenum at day 42. L. reuteri pLEM4158 (phy) and L. reuteri pLEM4159-cel/phy improved the villi height in the ileum at day 42. Taken together, transformed L. reuteri can improve blood calcium, phosphorus, and glucose metabolism and intestinal development in broilers, but does not affect carcass characteristics.(AU)


Assuntos
Animais , Galinhas/microbiologia , Probióticos/efeitos adversos , Limosilactobacillus reuteri , Carne/análise , Biomarcadores , Celulase/análise
3.
Acta sci., Anim. sci ; 41: e45100, 2019. tab, graf
Artigo em Inglês | VETINDEX | ID: biblio-1459855

RESUMO

The aim of this study was to evaluate the action of commercial and non-commercial cellulase and pectinase on rice husk and Tifton 85 hay hydrolyses. The hydrolysis kinetics of the substrates with commercial cellulase and pectinase were evaluated and the hydrolysis at different temperature and agitation conditions was maximized using experimental design. The combined use of commercial and non-commercial enzymes under optimized conditions was evaluated. The pre-treatment of the residues was also investigated by milling and different concentrations of NaOH. Finally, the effect of the hydrolysis on the bromatological composition of the residues was evaluated. The best hydrolysis times of rice husk and Tifton 85 hay were 10 and 12h for commercial cellulase, 12 and 14h for noncommercial cellulase, 10 and 14h for commercial pectinase and 16 and 20h for non-commercial pectinase, respectively. The highest hydrolysis values were obtained using commercial cellulase with 1:50 (w:v enzyme:water) dilution rate, at 45ºC and 300 rpm agitation for both substrates, reaching 20.6% maximum percentage for Tifton 85 hay and 11.6% for rice husk. The combined use of commercial enzymes did not increase hydrolysis percentage. The pre-treatment using 7.5% NaOH and 0.5 mm grain size significantly increased the rice husk and Tifton 85 hay hydrolyses (60-80%), either using commercial cellulase or pectinase enzymes. The use of non-commercial enzymes provided 18-30% hydrolysis obtained from commercial ones. Bromatological analyzes indicated a reduction in neutral detergent fiber and acid detergent fiber content for rice husk and Tifton 85 hay when using pectinases and commercial cellulases.


Assuntos
Celulase/análise , Celulase/efeitos adversos , Cynodon/enzimologia , Poligalacturonase/análise , Poligalacturonase/efeitos adversos , Hidrólise
4.
Rev Argent Microbiol ; 48(4): 274-278, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27916329

RESUMO

Knowledge regarding the enzymatic machinery of fungi is decisive to understand their ecological role. The species of the genus Geastrum are known to grow extremely slowly in pure culture, which makes it difficult to evaluate physiological parameters such as enzyme activity. Qualitative assays were performed on isolates of four species of this genus, showing evidence of laccase, cellulase, pectinase, amylase and lipase activity and suggesting that a wide range of carbon sources can be exploited by these species. For the first time in this genus, quantitative assays verified manganese peroxidase activity (up to 0.6mU/g) in 30-day old cultures, as well as laccase, ß-glycosidase and ß-xylosidase activities.


Assuntos
Basidiomycota/enzimologia , Proteínas Fúngicas/análise , Peroxidases/análise , Amilases/análise , Basidiomycota/crescimento & desenvolvimento , Carbono/metabolismo , Celulase/análise , Meios de Cultura , Lacase/análise , Lipase/análise , Poligalacturonase/análise , Especificidade da Espécie
5.
Braz. j. microbiol ; Braz. j. microbiol;45(4): 1211-1220, Oct.-Dec. 2014. graf, mapas, tab
Artigo em Inglês | LILACS | ID: lil-741270

RESUMO

A systematized survey was conducted to find soil-borne microbes that degrade cellulose in soils from unique ecosystems, such as the Superpáramo, Páramo, and the High Andean Forest in the Nevados National Natural Park (NNNP), Colombia. These high mountain ecosystems represent extreme environments, such as high levels of solar radiation, low atmospheric pressure, and extreme daily changes in temperature. Cellulolytic activity of the microorganisms was evaluated using qualitative tests, such as growth in selective media followed by staining with congo red and iodine, and quantitative tests to determine the activity of endoglucanase, β-glucosidase, exoglucanase, and total cellulase. Microorganisms were identified using molecular markers, such as the 16S rRNA gene for bacteria and the internal transcribed spacer region (ITS) of ribosomal DNA for fungi. Multivariate statistical analysis (MVA) was used to select microorganisms with high cellulolytic capacity. A total of 108 microorganisms were isolated from the soils and, in general, the enzymatic activities of fungi were higher than those of bacteria. Our results also found that none of the organisms studied were able to degrade all the components of the cellulose and it is therefore suggested that a combination of bacteria and/or fungi with various enzymatic activities be used to obtain high total cellulolytic activity. This study gives an overview of the potential microorganism that could be used for cellulose degradation in various biotechnological applications and for sustainable agricultural waste treatment.


Assuntos
Bactérias/isolamento & purificação , Bactérias/metabolismo , Celulose/metabolismo , Fungos/isolamento & purificação , Fungos/metabolismo , Microbiologia do Solo , Bactérias/classificação , Bactérias/genética , Colômbia , Celulase/análise , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Fúngico/química , DNA Fúngico/genética , DNA de Helmintos/química , DNA de Helmintos/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Fungos/classificação , Fungos/genética , Hidrólise , /genética , Análise de Sequência de DNA
6.
Braz. J. Microbiol. ; 45(4): 1211-1220, Oct.-Dec. 2014. graf, mapas, tab
Artigo em Inglês | VETINDEX | ID: vti-29096

RESUMO

A systematized survey was conducted to find soil-borne microbes that degrade cellulose in soils from unique ecosystems, such as the Superpáramo, Páramo, and the High Andean Forest in the Nevados National Natural Park (NNNP), Colombia. These high mountain ecosystems represent extreme environments, such as high levels of solar radiation, low atmospheric pressure, and extreme daily changes in temperature. Cellulolytic activity of the microorganisms was evaluated using qualitative tests, such as growth in selective media followed by staining with congo red and iodine, and quantitative tests to determine the activity of endoglucanase, β-glucosidase, exoglucanase, and total cellulase. Microorganisms were identified using molecular markers, such as the 16S rRNA gene for bacteria and the internal transcribed spacer region (ITS) of ribosomal DNA for fungi. Multivariate statistical analysis (MVA) was used to select microorganisms with high cellulolytic capacity. A total of 108 microorganisms were isolated from the soils and, in general, the enzymatic activities of fungi were higher than those of bacteria. Our results also found that none of the organisms studied were able to degrade all the components of the cellulose and it is therefore suggested that a combination of bacteria and/or fungi with various enzymatic activities be used to obtain high total cellulolytic activity. This study gives an overview of the potential microorganism that could be used for cellulose degradation in various biotechnological applications and for sustainable agricultural waste treatment.


Assuntos
Bactérias/isolamento & purificação , Bactérias/metabolismo , Celulose/metabolismo , Fungos/isolamento & purificação , Fungos/metabolismo , Microbiologia do Solo , Bactérias/classificação , Colômbia , Celulase/análise , DNA Bacteriano/química , DNA Fúngico/química , DNA de Helmintos/química , DNA Espaçador Ribossômico/química , DNA Ribossômico/química , Fungos/classificação , Hidrólise
8.
Braz J Microbiol ; 45(4): 1211-20, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25763024

RESUMO

A systematized survey was conducted to find soil-borne microbes that degrade cellulose in soils from unique ecosystems, such as the Superpáramo, Páramo, and the High Andean Forest in the Nevados National Natural Park (NNNP), Colombia. These high mountain ecosystems represent extreme environments, such as high levels of solar radiation, low atmospheric pressure, and extreme daily changes in temperature. Cellulolytic activity of the microorganisms was evaluated using qualitative tests, such as growth in selective media followed by staining with congo red and iodine, and quantitative tests to determine the activity of endoglucanase, ß-glucosidase, exoglucanase, and total cellulase. Microorganisms were identified using molecular markers, such as the 16S rRNA gene for bacteria and the internal transcribed spacer region (ITS) of ribosomal DNA for fungi. Multivariate statistical analysis (MVA) was used to select microorganisms with high cellulolytic capacity. A total of 108 microorganisms were isolated from the soils and, in general, the enzymatic activities of fungi were higher than those of bacteria. Our results also found that none of the organisms studied were able to degrade all the components of the cellulose and it is therefore suggested that a combination of bacteria and/or fungi with various enzymatic activities be used to obtain high total cellulolytic activity. This study gives an overview of the potential microorganism that could be used for cellulose degradation in various biotechnological applications and for sustainable agricultural waste treatment.


Assuntos
Bactérias/isolamento & purificação , Bactérias/metabolismo , Celulose/metabolismo , Fungos/isolamento & purificação , Fungos/metabolismo , Microbiologia do Solo , Bactérias/classificação , Bactérias/genética , Celulase/análise , Colômbia , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Fúngico/química , DNA Fúngico/genética , DNA de Helmintos/química , DNA de Helmintos/genética , DNA Ribossômico/química , DNA Ribossômico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Fungos/classificação , Fungos/genética , Hidrólise , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
9.
Braz. j. microbiol ; Braz. j. microbiol;44(1): 225-234, 2013. ilus, tab
Artigo em Inglês | LILACS | ID: lil-676918

RESUMO

A rice straw -cellulose utilizing mold was isolated from rotted rice straw residues. The efficient rice straw degrading microorganism was identified as Trichoderma reesei. The results showed that different carbon sources in liquid culture such as rice straw, carboxymethyl cellulose, filter paper, sugar cane bagasse, cotton stalk and banana stalk induced T. reesei cellulase production whereas glucose or Potato Dextrose repressed the synthesis of cellulase. T. reesei cellulase was produced by the solid state culture on rice straw medium. The optimal pH and temperature for T. reesei cellulase production were 6 and 25 ºC, respectively. Rice straw exhibited different susceptibilities towards cellulase to their conversion to reducing sugars. The present study showed also that, the general trend of rice straw bioconversion with cellulase was more than the general trend by T. reesei. This enzyme effectively led to enzymatic conversion of acid, alkali and ultrasonic pretreated cellulose from rice straw into glucose, followed by fermentation into ethanol. The combined method of acid pretreatment with ultrasound and subsequent enzyme treatment resulted the highest conversion of lignocellulose in rice straw to sugar and consequently, highest ethanol concentration after 7 days fermentation with S. cerevisae yeast. The ethanol yield in this study was about 10 and 11 g.L-¹.


Assuntos
Biomassa , Carbono , Celulase/análise , Celulase/isolamento & purificação , Etanol/análise , Microbiologia Industrial , Resíduos de Alimentos , Oryza/enzimologia , Trichoderma/enzimologia , Trichoderma/isolamento & purificação , Hidrólise , Métodos , Métodos
10.
Braz. j. microbiol ; Braz. j. microbiol;43(3): 1103-1111, July-Sept. 2012. ilus, graf, tab
Artigo em Inglês | LILACS | ID: lil-656680

RESUMO

In the current study, one thermostable endoglucanase was purified from Penicillium notatum NCIM NO-923 through mixed solid state fermentation of waste cabbage and bagasse. The molecular weight of the purified enzyme was 55kDa as determined by SDS polyacrylamide gel electrophoresis (SDS-PAGE). The enzyme had low activation energy (Ea) of 36.39KJ mol-1 for carboxymethyl cellulose hydrolysis and the enthalpy and entropy for irreversible inactivation was 87 kJ mol −1 and 59.3 J mol −1 K−1 respectively. The enzyme was quite thermostable with a Tm value of 62.2˚C. The pKa1 and pKa2 of ionizable groups of the active sites were 2.5 and 5.3 respectively. Apparent Km, Vmax and Kcat of the enzyme were found to be 5.2 mg mL-1, 80 U/gds and 322.4 sec-1 respectively. The enzyme showed about 1.4 fold increased activity in presence of 10mM MgSO4. Adsorption of endoglucanase on Avicel at wide pH range was studied at different temperatures. Langmuir type adsorption isotherm at 10˚C showed maximum adsorption strength of enzyme at pH 3.0, which was in a range of optimum pH of the enzyme.


Assuntos
Humanos , Brassica , Celulase/análise , Entropia , Ativação Enzimática , Fermentação , Isoterma , Penicillium chrysogenum/isolamento & purificação , Eletroforese Descontínua , Amostras de Alimentos , Hidrólise , Microbiologia Industrial
11.
World J Microbiol Biotechnol ; 28(5): 1989-95, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22806020

RESUMO

Opuntia ficus-indica Mill. (forage cactus) is farmed with relative success in the semi-arid region of the Brazilian northeast for commercial purposes, particularly as forage and food. Endophytic microorganisms are those that can be isolated inside plant tissues and can be a new source to production of enzymes with different potentialities. The objective of this study was to describe the richness of endophytic fungi from O. ficus-indica and to detect the capacity of these species to produce extracellular hydrolytic enzymes. Forty-four endophytic fungi species were isolated. Among them, the most commonly found were Cladosporium cladosporioides (20.43%) and C. sphaerospermum (15.99%). Acremonium terricola, Monodictys castaneae, Penicillium glandicola, Phoma tropica and Tetraploa aristata are being reported for the first time as endophytic fungi for Brazil. The majority of isolated fungi exhibited enzymatic potential. Aspergillus japonicus and P. glandicola presented pectinolytic activity. Xylaria sp. was the most important among the other 14 species with positive cellulase activity. All 24 isolates analysed were xylanase-positive. Protease was best produced by isolate PF103. The results indicate that there is a significant richness of endophytic fungi in O. ficus-indica, and that these isolates indicate promising potential for deployment in biotechnological processes involving production of pectinases, cellulases, xylanases and proteases.


Assuntos
Biodiversidade , Endófitos/enzimologia , Endófitos/isolamento & purificação , Fungos/enzimologia , Fungos/isolamento & purificação , Opuntia/microbiologia , Brasil , Celulase/análise , Endófitos/classificação , Fungos/classificação , Programas de Rastreamento/métodos , Peptídeo Hidrolases/análise , Poligalacturonase/análise , Xilosidases/análise
12.
World J Microbiol Biotechnol ; 28(5): 2249-56, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22806048

RESUMO

Antarctic environments can sustain a great diversity of well-adapted microorganisms known as psychrophiles or psychrotrophs. The potential of these microorganisms as a resource of enzymes able to maintain their activity and stability at low temperature for technological applications has stimulated interest in exploration and isolation of microbes from this extreme environment. Enzymes produced by these organisms have a considerable potential for technological applications because they are known to have higher enzymatic activities at lower temperatures than their mesophilic and thermophilic counterparts. A total of 518 Antarctic microorganisms, were isolated during Antarctic expeditions organized by the Instituto Antártico Uruguayo. Samples of particules suspended in air, ice, sea and freshwater, soil, sediment, bird and marine animal faeces, dead animals, algae, plants, rocks and microbial mats were collected from different sites in maritime Antarctica. We report enzymatic activities present in 161 microorganisms (120 bacteria, 31 yeasts and 10 filamentous fungi) isolated from these locations. Enzymatic performance was evaluated at 4 and 20°C. Most of yeasts and bacteria grew better at 20°C than at 4°C, however the opposite was observed with the fungi. Amylase, lipase and protease activities were frequently found in bacterial strains. Yeasts and fungal isolates typically exhibited lipase, celullase and gelatinase activities. Bacterial isolates with highest enzymatic activities were identified by 16S rDNA sequence analysis as Pseudomonas spp., Psychrobacter sp., Arthrobacter spp., Bacillus sp. and Carnobacterium sp. Yeasts and fungal strains, with multiple enzymatic activities, belonged to Cryptococcus victoriae, Trichosporon pullulans and Geomyces pannorum.


Assuntos
Bactérias/enzimologia , Bactérias/isolamento & purificação , Microbiologia Ambiental , Fungos/enzimologia , Fungos/isolamento & purificação , Amilases/análise , Regiões Antárticas , Bactérias/classificação , Bactérias/genética , Celulase/análise , Análise por Conglomerados , Temperatura Baixa , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Fúngico/química , DNA Fúngico/genética , Fungos/classificação , Fungos/genética , Gelatinases/análise , Lipase/análise , Filogenia , Análise de Sequência de DNA
13.
Curr Microbiol ; 63(6): 581-7, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21964940

RESUMO

The natural biodiversity that is found in tropical areas offers countless biotechnological opportunities; especially if we take in account that many biomolecules from several microorganisms have supported for many years, different industrial applications in areas such as pharmacology, agro-industry, bioprocess, environmental technology, and bioconversion. In order to find new lignocellulolytic enzymes and evaluate bamboo fibers as substrate, Schizophyllum commune a fungus with broad distribution was isolated and grown during 15 days in liquid culture medium containing 1% lignocellulosic fibers from bamboo, banana stem, and sugarcane bagasse. The enzymatic activity of xylanase, mannanase, polygalacturonase, CMCase, FPase, and avicelase were evaluated. Sugarcane bagasse and banana stem showed to induce higher hollocellulase activity when compared with bamboo as the main carbon source. The physical mechanism that the fungus uses to degrade bamboo was observed not only in fibers naturally infected but also in healthy fibers that were treated and untreated with enzyme solution. SEM analysis showed the structural disruption and invasion of the vascular bundles, parenchyma cells, and parenchymatous tissues as a consequence of the presence of this fungus and the catalytic action of its enzymes into the plant tissue.


Assuntos
Bambusa/microbiologia , Celulase/metabolismo , Schizophyllum/enzimologia , Bambusa/ultraestrutura , Carboidratos/análise , Celulase/análise , Microscopia Eletrônica de Varredura , Schizophyllum/crescimento & desenvolvimento
14.
Braz. j. microbiol ; Braz. j. microbiol;42(3): 909-918, July-Sept. 2011. ilus, tab
Artigo em Inglês | LILACS | ID: lil-607519

RESUMO

Due to the connection between enzymatic activity and degradation of different fractions of organic matter, enzyme assays can be used to estimate degradation rates of particulate and dissolved organic carbon in freshwater systems. The aim of this study was to quantify and model the enzymatic degradation involving the decomposition of macrophytes, describing temporal activity of cellulases (EC 3.2.1.4 and EC 3.2.1.91) and xylanase (EC 3.2.1.8) during in situ decomposition of three aquatic macrophytes (Salvinia sp., Eichhornia azurea and Cyperus giganteus) on the surface and water-sediment interface (w-s interface) of an oxbow lagoon (Óleo lagoon) within a natural Brazilian Savanna Reserve. Overall, the enzymatic degradation of aquatic macrophytes in Óleo lagoon occurred during the whole year and was initiated together with leaching. Xylanase production was ca. 5 times higher than cellulase values due to easy access to this compound by cellulolytic microorganisms. Enzymatic production and detritus mass decay were similar on the surface and w-s interface. Salvinia sp. was the most recalcitrant detritus, with low mass decay and enzymatic activity. E. azurea and C. giganteus decomposition rates and enzymatic production were high and similar. Due to the physicochemical homogeneity observed in the Óleo lagoon, the differences between the decay rates of each species are mostly related with detritus chemical quality.


Assuntos
Água Doce/análise , Ambiente Aquático/análise , Carbono , Ensaios Enzimáticos Clínicos , Celulase/análise , Ativação Enzimática , Macrófitas , Laguna Costeira , Métodos , Métodos , Amostras de Água
15.
Braz. j. microbiol ; Braz. j. microbiol;42(1): 75-83, Jan.-Mar. 2011. ilus, tab
Artigo em Inglês | LILACS | ID: lil-571377

RESUMO

Enzymatic activity during decomposition is extremely important to hydrolyze molecules that are assimilated by microorganisms. During aquatic macrophytes decomposition, enzymes act mainly in the breakdown of lignocellulolytic matrix fibers (i.e. cellulose, hemicellulose and lignin) that encompass the refractory fraction from organic matter. Considering the importance of enzymatic activities role in decomposition processes, this study aimed to describe the temporal changes of xylanase and cellulose activities during anaerobic decomposition of Ricciocarpus natans (freely-floating), Oxycaryum cubense (emergent) and Cabomba furcata (submersed). The aquatic macrophytes were collected in Óleo Lagoon, Luiz Antonio, São Paulo, Brazil and bioassays were accomplished. Decomposition chambers from each species (n = 10) were set up with dried macrophyte fragments and filtered Óleo Lagoon water. The chambers were incubated at 22.5ºC, in the dark and under anaerobic conditions. Enzymatic activities and remaining organic matter were measured periodically during 90 days. The temporal variation of enzymes showed that C. furcata presented the highest decay and the highest maximum enzyme production. Xylanase production was higher than cellulase production for the decomposition of the three aquatic macrophytes species.


Assuntos
Microrganismos Aquáticos , Bioensaio , Celulase/análise , Microbiologia Ambiental , Reativadores Enzimáticos , Macrófitas , Peptídeo Hidrolases , Xilanos/análise , Ativação Enzimática , Laguna Costeira , Métodos , Métodos
16.
FEMS Microbiol Ecol ; 76(1): 1-13, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21223324

RESUMO

Nahuel Huapi (NH) Lake is an oligotrophic temperate lake of glacial origin with high transparency, surrounded by well-developed forests and located at San Carlos de Bariloche, Nahuel Huapi National Park, in Patagonia, Argentina. In this lake, we characterized yeast distribution and diversity along a south-to-north transect and established a relationship between the ability to produce photoprotective compounds (PPCs) (carotenoid pigments and mycosporines) and the occurrence of yeast at different collection points. Subsurface water samples were filtered for yeast isolation. Total yeast counts ranged between 22 and 141 CFU L(-1) , and the highest values corresponded to the most impacted sites. Littoral sites had a low proportion of yeast-producing PPCs and this group prevailed in pelagic sites. This is probably a result of the high transparency of the water and the increased UV exposure. The yeast community from NH Lake showed a high species richness and a uniform distribution of taxa between pelagic and border collection points. Yeasts were identified as belonging to 14 genera and 34 species. Rhodotorula mucilaginosa and Cryptococcus victoriae were the most frequently found species, representing 14.4% and 13.6% of the total yeast isolates, respectively. Most of the yeast isolates demonstrated at least one extracellular enzymatic activity (mainly cellulase and lipase activities), which suggested that these microorganisms are metabolically active in the lake.


Assuntos
Biodiversidade , Cryptococcus/isolamento & purificação , Rhodotorula/isolamento & purificação , Microbiologia da Água , Aminoácidos/análise , Argentina , Carotenoides/análise , Celulase/análise , Contagem de Colônia Microbiana , Cryptococcus/classificação , Cryptococcus/enzimologia , Impressões Digitais de DNA , DNA Fúngico/genética , Lipase/análise , Rhodotorula/classificação , Rhodotorula/enzimologia , Análise de Sequência de DNA
17.
Rev. colomb. biotecnol ; 12(2): 139-150, dic. 2010. ilus, graf, tab
Artigo em Espanhol | LILACS | ID: lil-590780

RESUMO

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.


Assuntos
Celulase/análise , Celulase/biossíntese , Celulase/genética , Celulase/imunologia , Celulase/química , Celulase/síntese química , Aspergillus niger/enzimologia , Aspergillus niger/fisiologia , Aspergillus niger/genética , Aspergillus niger/imunologia , Aspergillus niger/química
18.
Rev. colomb. biotecnol ; 12(2): 163-175, dic. 2010. graf, tab
Artigo em Espanhol | LILACS | ID: lil-590782

RESUMO

En el presente trabajo se describe la producción de las enzimas fitasa, celulasa, xilanasa y proteasa con Aspergillus ficuum cepa DSM 932 mediante fermentación en estado sólido (SSF) usando torta de canola y pomaza de cranberry como sustratos. Como medida indirecta de la producción de las enzimas se usó en cada caso la actividad enzimática. la torta de canola resultó ser un mejor sustrato para fitasa, celulasa y xilanasa, en tanto que la pomaza de cranberry resultó ser un sustrato potencial para proteasa. Mediante ultrafiltración escalonada fue posible purificar parcialmente los extractos enzimáticos de fitasa, celulasas y xilanasas, obtenidos a partir de torta de canola. La fitasa resultó tener un tamaño >100 kDa, en tanto que las celulasas y xilanasas presentan actividad en los retenidos de 10, 30 y 50 kDa, lo que indicaría que las isoenzimas de ambos complejos tienen pesos moleculares que oscilan entre 10 y 100 kDa.


In this paper, describes the production of the enzymes phytase, cellulase, xylanase and protease by Aspergillus ficuum DSM 932 strain, in solid state fermentation (SSF) using canola cake and cranberry pomace as substrates. The enzyme activity was used in each case as an indirect measure of the enzymes production. Canola meal turned out to be a better substrate for phytase, cellulase and xylanase, while cranberry pomace was found to be a potential substrate for protease. Various ultrafiltration operations were carried out, decreasing the cut off membranes out in order to purify partially extracts of enzymes phytase, cellulase and xylanase, obtained from canola meal. Phytase was found to have a size >100 kDa, whereas cellulase and xylanase activity present in the retained 10, 30 and 50 kDa, suggesting that isozymes of both complexes have molecular weights ranging between 10 and 100 kDa.


Assuntos
/análise , Agroindústria/análise , Agroindústria/efeitos adversos , Agroindústria/métodos , Celulase/análise , /análise , Fermentação/genética , Fermentação/imunologia
19.
J Appl Microbiol ; 103(6): 2196-204, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18045402

RESUMO

AIM: To evaluate the solid-state fermentation (SSF) production of cellulase and hemicellulases (xylanases), by Penicillium echinulatum 9A02S1, in experiments carried out with different concentrations of the pretreated sugar cane bagasse (PSCB) and wheat bran (WB). METHODS AND RESULTS: This study reports the production of xylanolytic and cellulolytic enzymes by P. echinulatum 9A02S1 using a cheap medium containing PSCB and WB under SSF. The highest amounts of filter paper activity (FPA) could be measured on mixtures of PSCB and WB (32.89 +/- 1.90 U gdm(-1)). The highest beta-glucosidase activity was 58.95 +/- 2.58 U gdm(-1) on the fourth day. The highest activity for endoglucanases was 282.36 +/- 1.23 U gdm(-1) on the fourth day, and for xylanases the activity was around 10 U gdm(-1) from the second to the fourth day. CONCLUSIONS: The present work has established the potential of P. echinulatum for FPA, endoglucanase, beta-glucosidase and xylanase productions in SSF, indicating that WB may be partially substituted by PSCB. SIGNIFICANCE AND IMPACT OF THE STUDY: The incorporation of cheap sources, such as sugar cane bagasse, into media for the production of lignocellulose enzymes should help decrease the production costs of enzymatic complexes that can hydrolyse lignocellulose residues for the formation of fermented syrups, thus contributing to the economic production of bioethanol.


Assuntos
Celulases/metabolismo , Fibras na Dieta , Glicosídeo Hidrolases/metabolismo , Microbiologia Industrial , Penicillium/metabolismo , Saccharum , Reatores Biológicos/microbiologia , Celulase/análise , Celulase/metabolismo , Celulases/análise , Endo-1,4-beta-Xilanases/análise , Endo-1,4-beta-Xilanases/metabolismo , Fermentação , Glicosídeo Hidrolases/análise , beta-Glucosidase/análise , beta-Glucosidase/metabolismo
20.
J Appl Microbiol ; 101(2): 480-6, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16882157

RESUMO

AIMS: Ceriporiopsis subvermispora produces endoglucanase and beta-glucosidase when cultivated on cellulose or wood, but biodegradation of cellulose during biopulping by C. subvermispora is low even after long periods. To resolve this discrepancy, we grew C. subvermispora on Pinus taeda wood chips and purified the major beta-glucosidases it produced. Kinetic parameters were determined to clear if this fungus produces enzymes capable of yielding assimilable glucose from wood. METHODS AND RESULTS: Ceriporiopsis subvermispora was grown on P. taeda wood chips under solid-state fermentation. After 30 days, the crude extract obtained from enzyme extraction with sodium acetate buffer 50 mmol l(-1), pH 5.4, was filtrated in membranes with a molecular mass exclusion limit of 100 kDa. Enzyme purification was carried out using successively Sephacryl S-300 gel filtration. The retained fraction attained 76% of beta-glucosidase activity with 3.7-fold purification. Two beta-glucosidases were detected with molecular mass of 110 and 53 kDa. We have performed a characterization of the enzymatic properties of the beta-glucosidase of 110 kDa. The optimum pH and temperature were 3.5 and 60 degrees C, respectively. The K(m) and V(max) values were respectively 3.29 mmol l(-1) and 0.113 micromol min(-1) for the hydrolysis of p-nitrophenyl-beta-glucopyranoside (pNPG) and 2.63 mmol l(-1) and 0.103 micromol min(-1), towards cellobiose. beta-Glucosidase activity was strongly increased by Mn(2+) and Fe(3+), while Cu(2+) severely inhibited it. CONCLUSIONS: Ceriporiopsis subvermispora produces small amounts of beta-glucosidase when grown on wood. The gel filtration and polyacrylamide gel electrophoresis data revealed the existence of two beta-glucosidases with 110 and 53 kDa. The 110 kDa beta-glucosidase from C. subvermispora can be efficiently purified in a single step by gel filtration chromatography. The enzyme has an acid pH optimum with similar activity on pNPG and cellobiose and is thus typical beta-glucosidase. SIGNIFICANCE AND IMPACT OF THE STUDY: Ceriporiopsis subvermispora produces beta-glucosidase with limited action during wood decay making able its use for the production of biomechanical and biochemical pulps. The results presented in this paper show the importance of studying the behaviour of beta-glucosidases during biopulping.


Assuntos
Basidiomycota/enzimologia , Celulose/metabolismo , Microbiologia Ambiental , Glucose/biossíntese , Madeira , beta-Glucosidase/metabolismo , Biodegradação Ambiental , Reatores Biológicos , Celulase/análise , Celulase/metabolismo , Eletroforese em Gel de Poliacrilamida , Temperatura Alta , Concentração de Íons de Hidrogênio , Pinus taeda , Especificidade por Substrato , beta-Glucosidase/análise
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