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Prospects for Bio‐Industrial Application of an Extremely Alkaline Mannanase From Bacillus subtilis subsp. inaquosorum CSB31
Author(s) -
Regmi Sudip,
Yoo Hah Y.,
Choi Yun H.,
Choi Yoon S.,
Yoo Jin C.,
Kim Seung W.
Publication year - 2017
Publication title -
biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.144
H-Index - 84
eISSN - 1860-7314
pISSN - 1860-6768
DOI - 10.1002/biot.201700113
Subject(s) - bacillus subtilis , enzyme kinetics , size exclusion chromatography , chemistry , hydrolysis , nuclear chemistry , enzyme , urea , activation energy , chromatography , protease , biochemistry , bacteria , organic chemistry , biology , active site , genetics
Mannan‐degrading enzymes have been growing interest in bio‐industrial applications, such as the pulp and paper, food, and pharmaceutical industries. In this study, an extremely alkaline mannanase (MnB31) is produced by Bacillus subtilis subsp. inaquosorum CSB31. MnB31 is purified to 17.92‐fold with a 21.51% yield and specific activity of 1,796.13 U mg −1 by anion‐exchange and gel filtration column chromatography. The biochemical characterization of MnB31 is performed, and the results are as follows: molecular weight of ≈47 kDa with an optimum temperature of 60 °C and pH of 12.5. The enzyme is strongly activated by Co 2+ , Mn 2+ , Na + , and K + , and inhibited by Zn 2+ , Ni 2+ , and Mg 2+ . Halo‐tolerance (10% NaCl), urea stability (3 M), and protease resistance are also observed. The kinetic parameters of MnB31 are found to be K m of 0.043 mg ml −1 , and V max of 1,046 ± 3.605 U mg −1 , respectively. In addition, the thermodynamical parameters are investigated; the activation energy ( E a ) is found to be 31.36 kJ mol −1 with a K cat value of 156.9 × 10 4 s −1 , ΔH (28.59 kJ mol −1 ), ΔG (42.38 kJ mol −1 ), ΔS (−41.39 J mol −1 K −1 ), Q 10 (1.40), ΔG E–S (−8.697 kJ mol −1 ), and ΔG E‐T (−48.22 kJ mol −1 ). These results suggest that MnB31 has potential bio‐industrial application, due to its greater hydrolytic efficiency and feasibility of enzymatic reaction.