Study on Melanized Shrimp Reveals Bacillus sp and Acinetobacter sp as Potential Sources for Bacterial Tyrosinase

Abstract

Melanin is a biopolymer produced by phenol oxidases group of enzymes and plays an important role in radiational, thermal and biochemical stress tolerance. This pharmacologically active pigment has been reported to be produced by bacteria. However, there is a paucity of data for bacteria associated with melanisation in shrimp. In this context the present study was undertaken. The presence of bacteria with the extracellular phenol oxidase production from the melanized appendages of Penaeus vannamei is studied. Market drawn samples of white leg shrimp with melanization were checked for possible intervention of bacteria with phenol oxidase production. Out of 24 isolated checked, three bacterial isolates viz, TMA7, TMA9 and TMA10 shown potential phenol oxidase production by positive and negative screening with tyrosine. The sequencing analysis of 16S rRNA fragment confirmed that the TMA7, TMA9, TMA10 bacterial isolates were Bacillus sp, Acinetobacter sp, and Bacillus megaterium respectively. The study also suggests that Bacillus sp and Acinetobacter sp could be a potential source for tyrosinase which can be used in the fish processing industry.