Endophytic fungi in plant tissues produce a wide range of secondary metabolites and enzymes, which exhibit a variety of biological activities. In the present study, litter endophytic fungi were isolated from a fire-prone forest and screened for thermostable cellulases. Among nine endophytic fungi tested, two isolates, Bartalinia pondoensis and Phoma sp., showed the maximum cellulase activity. Bartalinia pondoensis was further selected for its cellulase production and characterization. Among the carbon and nitrogen sources tested, maximum cellulase production was observed with maltose and yeast extract, and the eucalyptus leaves and rice bran served as the best natural substrates. The cellulase activity increased with increasing temperature, with maximum activity recorded at 100 °C. The maximum CMCase activity was observed between pH 6.0 and 7.0 and retained 80% of its activity in the pH range of 8-10. Partially purified cellulase of B. pondoensis retained 50% of its activity after 2 h of incubation at 60 °C, 80 °C and 100 °C. These results suggest that litter endophytic fungus B. pondoensis is a potential source for the production of thermostable and alkali-tolerant cellulase.
This study aimed to isolate and characterize a novel cellulolytic enzyme from black goat rumen by using a culture-independent approach. A metagenomic fosmid library was constructed from black goat rumen contents and screened for a novel cellulase. The KG37 gene encoding a protein of 858 amino acid residues (92.7 kDa) was isolated. The deduced protein contained a glycosyl hydrolase family 74 (GH74) domain and showed 77% sequence identity to two endo-1,4-β-glucanases from Fibrobacter succinogenes. The novel GH74 cellulase gene was overexpressed in Escherichia coli, and its protein product was functionally characterized. The recombinant GH74 cellulase showed a broad substrate spectrum. The enzyme exhibited its optimum activity at pH 5.0 and temperature range of 20-50 °C. The enzyme was thermally stable at pH 5.0 and at a temperature of 20-40 °C. The novel GH74 cellulase can be practically exploited to convert lignocellulosic biomass to value-added products in various industrial applications in future.
- MeSH
- bachor mikrobiologie MeSH
- celulasa chemie genetika izolace a purifikace MeSH
- Escherichia coli genetika metabolismus MeSH
- exprese genu MeSH
- Fibrobacter enzymologie genetika MeSH
- genetické testování MeSH
- genová knihovna MeSH
- klonování DNA MeSH
- koncentrace vodíkových iontů MeSH
- kozy mikrobiologie MeSH
- metagenom * MeSH
- metagenomika MeSH
- molekulová hmotnost MeSH
- rekombinantní proteiny genetika izolace a purifikace metabolismus MeSH
- sekvenční homologie MeSH
- stabilita enzymů MeSH
- substrátová specifita MeSH
- teplota MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
