Open AccessCharacterization of a gene encoding cellulase from uncultured soil bacteria
Author(s) -
Kim SooJin,
Lee ChangMuk,
Han BoRam,
Kim MinYoung,
Yeo YunSoo,
Yoon SangHong,
Koo BonSung,
Jun HongKi
Publication year - 2008
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2008.01097.x
Subject(s) - cellulase , cellobiose , biochemistry , chemistry , hydrolysis , sequence analysis , enzyme , bacteria , peptide sequence , biology , microbiology and biotechnology , gene , genetics
To detect cellulases encoded by uncultured microorganisms, we constructed metagenomic libraries from Korean soil DNAs. Screenings of the libraries revealed a clone pCM2 that uses carboxymethyl cellulose (CMC) as a sole carbon source. Further analysis of the insert showed two consecutive ORFs ( celM2 and xynM2 ) encoding proteins of 226 and 662 amino acids, respectively. A multiple sequence analysis with the deduced amino acid sequences of celM2 showed 36% sequence identity with cellulase from the Synechococcus sp., while xynM2 had 59% identity to endo‐1,4‐β‐xylanase A from Cellulomonas pachnodae . The highest enzymatic CMC hydrolysis was observable at pH 4.0 and 45 °C with recombinant CelM2 protein. Although the enzyme CelM2 additionally hydrolyzed avicel and xylan, no substrate hydrolysis was observed on oligosaccharides such as cellobiose, p NP‐β ‐ cellobioside, p NP‐β‐glucoside, and p NP‐β‐xyloside. These results showed that CelM2 is a novel endo‐type cellulase.