Cloning and Characterizing the Thermophilic and Detergent Stable Cellulase CelMytB from Saccharophagus sp. Myt-1

Abstract

We previously isolated and reported a second species of the Saccharophagus genus, Saccharophagus sp. strain Myt-1. In the present study, a cellulase gene (celMytB) from the genomic DNA of Myt-1 was cloned and characterized. The DNA sequence fragment contained an open reading frame of 1,893 bp that encoded a protein of 631 amino acids with an estimated molecular mass of 66.8 kDa. The deduced protein, CelMytB, had a catalytic domain that contained a conserved signature sequence (VIYEIYNEPL) of glycosyl hydrolase family 5 and a CBM6 cellulose binding module. CelMytB showed optimal activity at 55°C and pH 6.5, which is similar to the optimal temperature and pH profile of cel5H, an endoglucanase from the closely related S. degradans 2-40. However, the cellulase (degradation of soluble cellulose) and avicelase (degradation of crystalline cellulose) activities of CelMytB were about 3-fold and 100-fold higher, respectively, than the equivalent activities of cel5H. Moreover, CelMytB could degrade xylan. From the zymogram results, we speculated that the catalytic domain of CelMytB had high activity even without the cellulose binding module. The presence of some detergents stimulated the cellulase activity of CelMytB.

Inhibition of extracellular proteases improves the production of a xylanase in Parageobacillus thermoglucosidasius

“…The reason for this is not clear, but it is possible that the detergent used to solubilise the membrane fraction (Triton X-100) enhances the activity of XynA1, either directly or by increasing accessibility of the substrate to enzymatic degradation. Stimulating effects of detergents on the activity of enzymes degrading lignocellulosic substrates have been observed before [ 17 , 18 ], and we will investigate this for XynA1 in more detail in a future study.…”

Isolation of cellulase-producing <i>Microbulbifer</i> sp. from marine teleost blackfish (<i>Girella melanichthys</i>) intestine and the enzyme characterization

“…Marine sediment-derived Saccharophagas sp. Myt-1 produced cellulase CelMytB, which had an optimum temperature at 55°C and activity at 25°C of 30% (Sakatoku et al, 2014). Our GL-2 cellulase was similar, suggesting that adaptation to the marine condition occurred at the enzyme level.…”

“…Cellulase has been isolated from bacteria, fungus, protists and arthropoda (Wheeler et al, 2007;Carvalho et al, 2014;Sakatoku et al, 2014;Bui and Lee, 2015). Bacteria isolates have various known origins: soil (Hu et al, 2006), algae (Trivedi et al, 2013;Wakabayashi et al, 2012), marine sediment (Sakatoku et al, 2014) and freshwater fish (Saha et al, 2006;Ray et al, 2010).…”

Characterization of a novel manganese dependent endoglucanase belongs in GH family 5 from Phanerochaete chrysosporium

“…Ca 2þ is reported to enhance the activity of endoglucanase GH5 from Hahella chejuensis (21) and Saccharophagus sp. Myt-1 (22), but this ion did not increase the rPcEg5A activity. The 3D crystal structure of cel5A from H. jecorina indicated cel5A contains magnesium ion ligand.…”