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Characterization of chitinase‐producing S erratia and B acillus strains isolated from insects
Author(s) -
Han KookIl,
Patnaik Bharat Bhusan,
Cho Ahra,
Lim Ho Kab,
Lee Jae Min,
Jang Young Geun,
Jeong Yun Seon,
Yoo Tae Kyeong,
Lee Gyeong Seok,
Han ManDeuk
Publication year - 2014
Publication title -
entomological research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.421
H-Index - 20
eISSN - 1748-5967
pISSN - 1738-2297
DOI - 10.1111/1748-5967.12056
Subject(s) - chitinase , serratia marcescens , biology , microbiology and biotechnology , serratia , hydrolysis , bacteria , strain (injury) , incubation , enzyme , chitin , biochemistry , escherichia coli , gene , pseudomonas , genetics , anatomy , chitosan
Chitinases ( EC 3.2.1.14) are enzymes that hydrolyze chitin by cleaving β‐1,4 N ‐glycosidic bonds. These enzymes have been used for multiple applications in biotechnology, especially for controlling insect pests and phytopathogenic fungi. In the present study, we isolated two chitinase‐producing bacteria strains from insects (strain SCH ‐1 from M oechotypa diphysis and strain SCH ‐2 from S phedanolestes impressicollis ). Serratia sp. SCH ‐1 was a short, rod‐shaped facultative anaerobe, while B acillus strain SCH ‐2 was a rod‐shaped endospore‐forming anaerobe. Strains SCH ‐1 and SCH ‐2 were identified as S erratia sp. and B acillus sp., respectively based on 16 S r RNA gene sequencing. Strain SCH ‐1 shared maximum homology (99.44%) with S erratia nematodiphila DZ 0503 SBS 1 and S erratia marcescens subsp. sakuensis KRED . Strain SCH ‐2 had a maximum homology of 99.24% with B acillus thuringiensis ATCC 10792 and B acillus toyonensis BCT ‐7112. Serratia sp. SCH ‐1 contained greater levels of saturated fatty acids, but the concentration of branched acids, especially iso‐ C 15:0 , was highest in B acillus sp. SCH ‐2. Serratia sp. SCH ‐1 possessed chitinase activity of 1.59 unit/mg protein after 5 days of incubation in culture medium. In contrast, B acillus sp. SCH ‐2 had a maximum activity of 0.84 unit/mg protein after 4 days of incubation. Chitinase isozymes produced by S erratia sp. SCH ‐1 appeared as five bands with sizes of 20, 26, 36, 45 and 54 k D a. Bacillus sp. SCH ‐2 showed a chitinase isozyme profile with three bands having sizes of 36, 45 and 50 k D a on SDS‐PAGE gels.