Efficient hydrolysis of holocellulose depends on a proper balance between cellulase (endoglucanase, exoglucanase, β-glucosidase) and xylanase activities. The present study aimed to induce the production of cellulases and xylanases using liquid cultures (one, two, three, and four fungal strains on the same bioreactor) of wild strains of Trichoderma harzianum, Aspergillus niger, and Fusarium oxysporum. The strains were identified by amplification and analysis of the ITS rDNA region and the obtained sequences were deposited in Genbank. Enzymes (endoglucanase, exoglucansae, β-glucosidase, and xylanase activities) and the profile of extracellular protein isoforms (SDS-PAGE) produced by different fungal combinations (N = 14) were analyzed by Pearson's correlation matrix and principal component analysis (PCA). According to our results, induction of endoglucanase (19.02%) and β-glucosidase (6.35%) were obtained after 4 days when A. niger and F. oxysporum were cocultured. The combination of A. niger-T. harzianum produced higher endoglucanase in a shorter time than monocultures. On the contrary, when more than two strains were cultured in the same reactor, the relationships of competition were established, trending to diminish the amount of enzymes and the extracellular protein isoforms produced. The xylanase production was sensible to stress produced by mixed cultures, decreasing their activity. This is important when the aim is to produce cellulase-free xylanase. In addition, exoglucanase activity did not change in the combinations tested.
- MeSH
- Ascomycota enzymologie růst a vývoj izolace a purifikace metabolismus MeSH
- Aspergillus niger enzymologie růst a vývoj izolace a purifikace metabolismus MeSH
- biomasa MeSH
- bioreaktory mikrobiologie MeSH
- celulasy biosyntéza metabolismus MeSH
- celulosa metabolismus MeSH
- fermentace MeSH
- fungální proteiny biosyntéza metabolismus MeSH
- Fusarium enzymologie růst a vývoj izolace a purifikace metabolismus MeSH
- kokultivační techniky * MeSH
- mikrobiální interakce fyziologie MeSH
- průmyslová mikrobiologie metody MeSH
- Trichoderma enzymologie růst a vývoj izolace a purifikace metabolismus MeSH
- xylosidasy biosyntéza metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
A metagenomic fosmid library was constructed from compost microbial communities that were collected from various farms throughout the Khon Kaen province, Thailand. The library was enriched in carboxymethylcellulose (CM-cellulose)--containing media prior to the screening of clones capable of degrading cellulosic materials. Two clones were selected for further subcloning and sequencing based on different patterns from restriction analysis. Deduced amino acid analysis of possible ORFs revealed one novel gene encoding an enzyme belonging to glycosyl hydrolase family 43 (GH43), which is a GH family rarely found in metagenomic studies. The most notable finding is that this enzyme, designated as Biof1_09, shows dual activities, namely endocellulase and endoxylanase activities. Biof1_09 showed greater than 50% of its activity under acidic conditions ranging from pH 3.5 to 5.5 with a pH optimum of 4.5. The optimum temperature of this enzyme was between 45 and 55 °C with an optimum of 50 °C. The properties of Biof1_09 make this enzyme an attractive candidate for large-scale expression for use in lignocellulose degradation for various bioprocess applications, including bioethanol fermentation.
- MeSH
- celulasa genetika metabolismus MeSH
- genová knihovna MeSH
- koncentrace vodíkových iontů MeSH
- metagenom * MeSH
- molekulární sekvence - údaje MeSH
- otevřené čtecí rámce MeSH
- půda * MeSH
- půdní mikrobiologie * MeSH
- sekvenční analýza DNA MeSH
- sekvenční homologie aminokyselin MeSH
- stabilita enzymů MeSH
- teplota MeSH
- xylosidasy genetika metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Thajsko MeSH
Production of the lignocellulose-degrading enzymes endo-1,4-β-glucanase, 1,4-β-glucosidase, cellobiohydrolase, endo-1,4-β-xylanase, 1,4-β-xylosidase, Mn peroxidase, and laccase was characterized in a common wood-rotting fungus Fomes fomentarius, a species able to efficiently decompose dead wood, and compared to the production in eight other fungal species. The main aim of this study was to characterize the 1,4-β-glucosidase produced by F. fomentarius that was produced in high quantities in liquid stationary culture (25.9 U ml(-1)), at least threefold compared to other saprotrophic basidiomycetes, such as Rhodocollybia butyracea, Hypholoma fasciculare, Irpex lacteus, Fomitopsis pinicola, Pleurotus ostreatus, Piptoporus betulinus, and Gymnopus sp. (between 0.7 and 7.9 U ml(-1)). The 1,4-β-glucosidase enzyme was purified to electrophoretic homogeneity by both anion-exchange and size-exclusion chromatography. A single 1,4-β-glucosidase was found to have an apparent molecular mass of 58 kDa and a pI of 6.7. The enzyme exhibited high thermotolerance with an optimum temperature of 60 °C. Maximal activity was found in the pH range of 4.5-5.0, and K (M) and V (max) values were 62 μM and 15.8 μmol min(-1) l(-1), respectively, when p-nitrophenylglucoside was used as a substrate. The enzyme was competitively inhibited by glucose with a K (i) of 3.37 mM. The enzyme also acted on p-nitrophenylxyloside, p-nitrophenylcellobioside, p-nitrophenylgalactoside, and p-nitrophenylmannoside with optimal pH values of 6.0, 3.5, 5.0, and 4.0-6.0, respectively. The combination of relatively low molecular mass and low K (M) value make the 1,4-β-glucosidase a promising enzyme for biotechnological applications.
- MeSH
- Coriolaceae chemie enzymologie genetika MeSH
- extracelulární prostor chemie enzymologie genetika MeSH
- fungální proteiny chemie genetika izolace a purifikace metabolismus MeSH
- kinetika MeSH
- stabilita enzymů MeSH
- substrátová specifita MeSH
- transport proteinů MeSH
- xylosidasy chemie genetika izolace a purifikace metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Saprotrophic wood-inhabiting basidiomycetes are the most important decomposers of lignin and cellulose in dead wood and as such they attracted considerable attention. The aims of this work were to quantify the activity and spatial distribution of extracellular enzymes in coarse wood colonised by the white-rot basidiomycete Fomes fomentarius and in adjacent fruitbodies of the fungus and to analyse the diversity of the fungal and bacterial community in a fungus-colonised wood and its potential effect on enzyme production by F. fomentarius. Fungus-colonised wood and fruitbodies were collected in low management intensity forests in the Czech Republic. There were significant differences in enzyme production by F. fomentarius between Betula pendula and Fagus sylvatica wood, the activity of cellulose and xylan-degrading enzymes was significantly higher in beech wood than in birch wood. Spatial analysis of a sample B. pendula log segment proved that F. fomentarius was the single fungal representative found in the log. There was a high level of spatial variability in the amount of fungal biomass detected, but no effects on enzyme activities were observed. Samples from the fruiting body showed high β-glucosidase and chitinase activities compared to wood samples. Significantly higher levels of xylanase and cellobiohydrolase were found in samples located near the fruitbody (proximal), and higher laccase and Mn-peroxidase activities were found in the distal ones. The microbial community in wood was dominated by the fungus (fungal to bacterial DNA ratio of 62-111). Bacterial abundance composition was lower in proximal than distal parts of wood by a factor of 24. These results show a significant level of spatial heterogeneity in coarse wood. One of the explanations may be the successive colonization of wood by the fungus: due to differential enzyme production, the rates of biodegradation of coarse wood are also spatially inhomogeneous.
- MeSH
- Bacteria enzymologie izolace a purifikace MeSH
- beta-glukosidasa metabolismus MeSH
- biodegradace MeSH
- bříza enzymologie mikrobiologie MeSH
- buk (rod) enzymologie mikrobiologie MeSH
- celulosa-1,4-beta-cellobiosidasa metabolismus MeSH
- chitinasy metabolismus MeSH
- Coriolaceae enzymologie izolace a purifikace MeSH
- DNA bakterií analýza MeSH
- DNA fungální analýza MeSH
- dřevo enzymologie mikrobiologie MeSH
- ekologie MeSH
- lakasa metabolismus MeSH
- lignin metabolismus MeSH
- mikrobiální společenstva MeSH
- peroxidasy metabolismus MeSH
- stromy enzymologie mikrobiologie MeSH
- xylany metabolismus MeSH
- xylosidasy metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
Saprotrophic cord-forming basidiomycetes are important decomposers of lignocellulosic substrates in soil. The production of extracellular hydrolytic enzymes was studied during the growth of two saprotrophic basidiomycetes, Hypholoma fasciculare and Phanerochaete velutina, across the surface of nonsterile soil microcosms, along with the effects of these basidiomycetes on fungi and bacteria within the soil. Higher activities of α-glucosidase, β-glucosidase, cellobiohydrolase, β-xylosidase, phosphomonoesterase and phosphodiesterase, but not of arylsulphatase, were recorded beneath the mycelia. Despite the fact that H. fasciculare, with exploitative hyphal growth, produced much denser hyphal cover on the soil surface than P. velutina, with explorative growth, both fungi produced similar amounts of extracellular enzymes. In the areas where the mycelia of H. fasciculare and P. velutina interacted, the activities of N-acetylglucosaminidase, α-glucosidase and phosphomonoesterase, the enzymes potentially involved in hyphal cell wall damage, and the utilization of compounds released from damaged hyphae of interacting fungi, were particularly increased. No significant differences in fungal biomass were observed between basidiomycete-colonized and noncolonized soil, but bacterial biomass was reduced in soil with H. fasciculare. The increases in the activities of β-xylosidase, β-glucosidase, phosphomonoesterase and cellobiohydrolase with increasing fungal:bacterial biomass ratio indicate the positive effects of fungal enzymes on nutrient release and bacterial abundance, which is reflected in the positive correlation of bacterial and fungal biomass content.
- MeSH
- alfa-glukosidasy analýza metabolismus MeSH
- Bacteria růst a vývoj MeSH
- Basidiomycota růst a vývoj metabolismus fyziologie MeSH
- biomasa MeSH
- celulosa-1,4-beta-cellobiosidasa analýza metabolismus MeSH
- houby růst a vývoj fyziologie MeSH
- hyfy růst a vývoj MeSH
- mycelium fyziologie MeSH
- půda chemie MeSH
- půdní mikrobiologie MeSH
- xylosidasy analýza metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
