Preliminary molecular identification of proteolytic and lipolytic-enzyme producing bacteria isolated from sediment of Litopenaeus vannamei pond

The enzyme is a catalyst that serves as an accelerator in a biochemical process. A hydrolytic enzyme is among the existing enzymes useful for environmental organic waste degradation. This research aimed to (1) investigate the ability of bacteria isolated from Litopenaeus vannamei pond sediment to produce proteolytic and lipolytic enzymes, (2) identify the isolates with 16S rRNA gene amplification, and (3) construct a phylogenetic tree according to the 16S rRNA genes. The preliminary proteolytic assay consisted of a skim milk agar medium and the lipolytic assay consisted of a Tween 20/80 medium or so-called precipitation test. Among 28 bacterial isolates, 4 of them showed potential for proteolytic activity and 6 of them showed lipolytic activity as well. Further, the amplification of 16S rRNA gene showed that 5 out of the 28 isolates were closely related to Bacillus infantis SA 3.2 (IM8), Marinobacter koreensis SB 1.1 (IM6), Vibrio algynolyticus SA 4.2 (IM6), Streptomyces euryhalinus SB 1.2 (IM6), and Cytobacillus kochii SC 3.4 (IM6). Amongst the most active isolate, one of the was included in Actinobacteria phylum. Many Bacilli strains shows enzymatic activity such as amylase, protease and lypase. The genus Marinobacter also found to be able to produce hydrolytic enzyme such as amylase and protease. Furthermore, the genus Vibrio such as V. algynoliticus produce several enzymes i.e., gelatinase, lecithinase, caseinase, amylase and lipase. In summary, the bacteria from L. vannamei pond sediment exhibit a potential as proteolytic and lipolytic enzyme producers.