Extracellular production of novel halotolerant, thermostable, and alkali-stable carboxymethyl cellulase by marine bacterium Marinimicrobium sp. LS-A18.
Cellulases which are active and stable under extreme conditions have attracted considerable attention because of their potential industrial applications. Marinimicrobium sp. LS-A18 showed high extracellular carboxymethylcellulase (CMCase) activity when grown on mineral salt medium containing carboxymethylcellulose as the sole carbon source. Maximum CMCase activity was obtained at 55°C and pH 7.0 in the absence of NaCl. Under the optimized fermentation conditions, the yield of CMCase was increased up to 2.5 U/ml, which was 3.1-fold higher than that before optimization. The enzyme retained 84 % of residual activity after incubation at 60°C for 1 h and more than 88 % of residual activity after incubation for 72 h in the presence of different pH (5-11) and NaCl concentrations (0-25 %, w/v), indicating it was halotolerant, thermostable and alkali-stable. These characteristics made the CMCase from Marinimicrobium sp. LS-A18 as a potentially novel biocatalyst in biotechnological and industrial applications.
Shandong Provincial Key Laboratory of Applied Mycology, College of Life Sciences, Qingdao Agricultural University, Qingdao 266109, China.
Kun
K
Zhao
Li-Zhong
LZ
Guo
Wei-Dong
WD
Lu
D000468:Alkalies / Q000378:metabolism; D034241:Alteromonadaceae / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism*; D002480:Cellulase / Q000737:chemistry* / Q000378:metabolism*; D002712:Chlorides / Q000378:metabolism; D004795:Enzyme Stability; D005110:Extracellular Space / Q000737:chemistry / Q000201:enzymology*; D007700:Kinetics; D012623:Seawater / Q000382:microbiology*; D013696:Temperature
D000468:Alkalies; D001426:Bacterial Proteins; D002712:Chlorides; D002480:Cellulase; C019826:carboxymethylcellulase; C001599:chlorite