Abstract
Eight genes encoding cellulolytic enzymes
were obtained by direct PCR amplification of genomic
DNA recovered from woodland soil samples. The direct
amplifications were carried out by using primers designed
from available online cellulase nucleotide sequences. The
isolated genes were all different from each other and
homologous to endo-b-1,4-glucanases of Bacillus subtilis.
The cellulases were functionally expressed in Escherichia
coli and tested on soluble substrate at 37 and 60 C,
showing different cellulolytic activities. Among these, the
enzyme renamed CelWS6 exhibited good activity at higher
temperatures. Further analysis of CelWS6 showed a high
performance in acid environments (between pH 4.0 and
6.0) and at elevated temperatures with its maximum
activity at pH 5.0 and 50 C. At the optimum pH, it was
very stable since more than 80 % of its original activity
was maintained after an incubation of 120 min at 60 C.
Because the cellulases had different cellulolytic activities,
but similar amino acid sequences, it was possible to assess
the relationship between sequence and protein function.
Lingua originale | Inglese |
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pagine (da-a) | 4317-4325 |
Numero di pagine | 9 |
Rivista | Molecular Biology Reports |
DOI | |
Stato di pubblicazione | Pubblicato - 2013 |
Keywords
- Bacillus subtilis
- Cellulases
- Soil recovered DNA
- Thermostability
- pH profile