Production, purification, and characterization of a thermo-alkali stable and metal-tolerant carboxymethylcellulase from newly isolated Bacillus methylotrophicus Y37

Duman Y., Yüzügüllü Karakuş Y., Sertel A., Polat F.

TURKISH JOURNAL OF CHEMISTRY, vol.40, pp.802-815, 2016 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 40
  • Publication Date: 2016
  • Doi Number: 10.3906/kim-1602-55
  • Journal Name: TURKISH JOURNAL OF CHEMISTRY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, TR DİZİN (ULAKBİM)
  • Page Numbers: pp.802-815
  • Keywords: Bacillus methylotrophicus, carboxymethylcellulase, isolation, purification, characterization, metal, thermostability, CELLULASE-PRODUCING BACTERIA, SUBTILIS, ENDOGLUCANASE, STRAIN, GROWTH, NOV.
  • Kocaeli University Affiliated: Yes

Abstract

A carboxymethylcellulose (CMC)-degrading bacterium was isolated from soil, identified as Bacillus methylotrophicus according to the physiological properties and analyses of 16S rRNA and a partial sequence of the gyrase A (gyrA) gene, and named as B. methylotrophicus Y37. The CMCase enzyme was purified to homogeneity by 20.4-fold with 21.73% recovery using single-step hydrophobic interaction chromatography and biochemically characterized. CMCase showed a molecular weight of approximately 50 kDa as determined by SDS-PAGE. The activity profile of the CMCase enzyme exhibited optimum activity at 45 degrees C and pH 5.0. The activity was highly stable at alkaline pH levels. More than 90% of the original CMCase activity was maintained at relatively high temperatures ranging from 55 to 65 degrees C. The enzyme activity was induced by Ca2+, Cd2+, CO2+, K+, Mg2+, and Na1+, whereas it was strongly inhibited by phenylmethanesulfonyl fluoride and iodoacetic acid. The enzyme tolerated Hg2+ up to 10 mM and presented hydrolytic activity towards glucan, filter paper, laminarin, and CMC but not o-nitrophenyl beta-D-galactopyranoside. Kinetic analysis of the purified enzyme showed K-m and V-max values of 0.19 mg mL(-1) and 7.46 U mL(-1), respectively. The biochemical properties of this CMCase make the enzyme a good candidate for many industrial applications.