Isolation and Characterization of Chitinase‐Producing Bacillus and Paenibacillus Strains from Salted and Fermented Shrimp, Acetes japonicus

Abstract

Chitinases catalyze the conversion of chitin and are produced by a wide range of bacteria. The biological applications of these enzymes have been exploited in food and pharmaceutical industries. We isolated 2 halophilic chitinase-producing novel strains of bacteria-SCH-1 and SCH-2 from Saeu-jeot, a traditional Korean salted and fermented food made with shrimp (Acetes japonicus). The isolated strains- SCH-1 and SCH-2 were Gram-positive, rod-shaped, endospore-forming facultative anaerobes, with strain SCH-2 showing peritrichous flagella. Molecular characterization of the 16S rRNA gene identified the strains SCH-1 and SCH-2 as Bacillus sp. and Paenibacillus sp. respectively. Basic Local Alignment Search Tool and subsequent phylogenetic analysis of strain SCH-1 showed an identity of 97.83% with Bacillus cereus ATCC 14579 (NR_074540), whereas strain SCH-2 showed an identity of 99.16% with Paenibacillus lautus JCM 9073 (NR_040882). Furthermore, the SCH-1 strain could use glucose, N-acetyl glucosamine, esculin, and maltose as carbon source substrates. Cellular fatty acid analysis showed that iso-C15:0 and anteiso-C15:0 are the major acids in strain SCH-1 and SCH-2, respectively. The SCH-1 strain showed a higher chitinase activity at 15.71 unit/mg protein compared with SCH-2 strain. Chitinase isozymes of Bacillus sp. SCH-1was expressed as 2 bands having sizes of 41 and 50 kDa, and as 4 bands with sizes of 30, 37, 45.7, and 50 kDa in Paenibacillus sp. SCH-2. The rich chitinase activity with the isozyme profiles of the isolated Bacillus and Paenibacillus strains provide advancement in the study of fermentation and may play putative functions in the chitin bioconversion of sea crustacean foods.

Characterization of chitinase‐producing Serratia and Bacillus strains isolated from insects

“…obtained from salted and fermented shrimp (Han et al . ). It appears that the fatty acid composition of Bacillus sp.…”

“…from salted and fermented shrimp that showed the highest level of chitinase activity at a pH just beyond 7.0 and when cell growth was in a stationary phase (Han et al . ). Other researchers have suggested that B. laterosporus (Shanmugaiah et al .…”

Hydrolytic Enzymes in Halophilic Bacteria, Properties and Biotechnological Potential

“…After culturing and appropriate incubation time, chitinolytic activity is visualized by a clear zones of chitin hydrolysis around colonies, as shown in Fig. 13.1f (Han et al 2014 ). Two chitinolytic bacteria, HCh1 and HCh2 strains identifi ed as genera Saccharospirillum and Arhodomonas , respectively were ( 2009b ) isolated from hypersaline lakes in Russia.…”

“…strain SCH-1 and Paenibacillus sp. strain SCH-2 isolated from a salted and fermented food (Han et al 2014 ) and Haloanaerobacter chitinovorans isolated from a solar saltern (Liaw and Mah 1992 ) exhibited chitinolytic activity. A moderately halophilic bacterium, Virgibacillus marismortui strain M3-23 that isolated from a Tunisian shallow salt lake produced a chitinase in the absence or presence of salt.…”

Bacterial Community Dynamics of Salted and Fermented Shrimp based on Denaturing Gradient Gel Electrophoresis

“…We previously reported isolation of chitinolytic Bacillus and Paenibacillus sp. from SFS using biochemical, phenotypic, and 16S rRNA‐based molecular phylogenetics study (Han and others ). Another study documented the bacterial communities of traditional and fermented seafoods from Jeju island of Korea using 16S rRNA gene‐clone library analyses and culture isolation (Kim and Park ).…”