A metagenomic approach for the identification and cloning of an endoglucanase from rice straw compost.
Gene
; 519(2): 360-6, 2013 May 01.
Article
em En
| MEDLINE
| ID: mdl-22903031
ABSTRACT
Over the years, culturable cellulase-producing microorganisms have been isolated from a variety of sources and genes of cellulolytic enzymes have been cloned. Then again, the "great plate count anomaly" phenomenon necessitates a culture-independent metagenomic approach for the isolation of cellulolytic genes from microorganisms in their natural environment. We have constructed a metagenomic library derived from rice straw composts. Of 2739 clones screened, a lambda clone carrying a 12kb genomic fragment was able to yield a clear zone on an agar plate containing carboxymethyl cellulose (CMC). A 4.7kb subclone, generated by restriction enzyme digestion, was found to harbor a GH12 cellulase gene, RSC-EG1, encoding 464 amino acids along with two other ORFs. The identified cellulolytic gene showed more than 70% similarity on the amino acid level with cellulase from Micromonospora aurantiaca and Thermobispora sp. Interestingly, RSC-EG1 contains a stretch of approximately 86 amino acids not present in either of these close relatives. Our results demonstrated that RSC-EG1, stable over a wide temperature and pH range, is a novel endoglucanase, and provided the first example of metagenomics approach to isolate cellulolytic gene from rice straw composts.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Oryza
/
Celulase
/
Metagenômica
Tipo de estudo:
Diagnostic_studies
Idioma:
En
Revista:
Gene
Ano de publicação:
2013
Tipo de documento:
Article