Identification of halotolerant Lysinibacillus sphaericus isolated from Indonesian traditional dry-salted fish

Abstract Halotolerant protease-producing bacteria are a potential source of culture starter for the fermentation of fishery products. To find potential culture starter that can be used for fish fermentation, isolation of indigenous halotolerant bacteria is a particularly important step. This study was carried out for the isolation and identification of proteolytic bacteria isolated from traditional dried fish in Indonesia. A total of 32 isolates were obtained from three types of dried salted fish ( ikan kotok, ikan belanak , and ikan kepala batu ). Out of 30 isolates, six showed casein hydrolysis on skim milk agar (SMA), however, only four isolates showed proteolytic activity on saline SMA (10% w/v NaCl) namely isolates UA10, UA11, UA12, and UA13. All strains were identified as Lysinibacillus sphaericus based on morphological and biochemical tests. Before it can be used for fermentation or other purposes, further characterization of Lysinibacillus sphaericus isolated from traditional Indonesian dried salted fish is required.