Characterization of chitinase‐producing Serratia and Bacillus strains isolated from insects. Issue 3 (23rd May 2014)

• Record Type: Journal Article
• Authors: Han, Kook‐Il; Patnaik, Bharat Bhusan; Cho, Ah‐ra; Lim, Ho Kab; Lee, Jae Min; Jang, Young Geun; Jeong, Yun Seon; Yoo, Tae Kyeong; Lee, Gyeong Seok; Han, Man‐Deuk
• Is Part Of: Entomological research. Volume 44:Issue 3(2014:May)
• Page Start: 109
• Page End: 120
• Publication Date: 2014-05-23
• Subjects: Insects -- Korea -- Periodicals; Entomology -- Periodicals; 595.709519
• DOI: 10.1111/1748-5967.12056
• Languages: English
• ISSNs: 1738-2297

Abstract

<abstract abstract-type="main"> <title>Abstract</title> <p>Chitinases (EC 3.2.1.14) are enzymes that hydrolyze chitin by cleaving β‐1, 4 <italic>N</italic>‐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 <italic>Moechotypa diphysis</italic> and strain SCH‐2 from <italic>Sphedanolestes impressicollis</italic>). <italic>Serratia</italic> sp. SCH‐1 was a short, rod‐shaped facultative anaerobe, while <italic>Bacillus</italic> strain SCH‐2 was a rod‐shaped endospore‐forming anaerobe. Strains SCH‐1 and SCH‐2 were identified as <italic>Serratia</italic> sp. and <italic>Bacillus</italic> sp., respectively based on <italic>16S</italic> rRNA gene sequencing. Strain SCH‐1 shared maximum homology (99.44%) with <italic>Serratia nematodiphila</italic> DZ0503SBS1 and <italic>Serratia marcescens</italic> subsp. <italic>sakuensis</italic> KRED. Strain SCH‐2 had a maximum homology of 99.24% with <italic>Bacillus thuringiensis</italic> ATCC 10792 and <italic>Bacillus toyonensis</italic> BCT‐7112. <italic>Serratia</italic> sp. SCH‐1 contained greater levels of saturated fatty acids, but the concentration of branched acids, especially iso‐C<sub>15:0</sub>, was highest in <italic>Bacillus</italic> sp. SCH‐2. <italic>Serratia</italic> sp. SCH‐1 possessed chitinase activity of 1.59 unit/mg protein after 5 days of incubation in culture medium. In contrast, <italic>Bacillus</italic> sp. SCH‐2 had a maximum activity of 0.84 unit/mg protein after 4 days of incubation. Chitinase isozymes produced by <italic>Serratia</italic> sp. SCH‐1 appeared as five bands with sizes of 20, 26, 36, 45 and 54 kDa. <italic>Bacillus</italic> sp. SCH‐2 showed a chitinase isozyme profile with three bands having sizes of 36, 45 and 50 kDa on SDS‐PAGE gels.</p> </abstract>