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Alcaligenes sp. JG3 is a local strain bacterium from Indonesia, isolated from cultivated corn field of Central Java. This bacterium is able to produce lipase with fairly high activity. In order to do lipase gene sequence characterization, two sets of primer pair were used in this study (primer Fjg3 5’- ATGACCGAGCTGACTGTAG-3’, Rjg3 5’-TCAGGAGGGGTAAATCCAC-3’ and internal primer Fi 5’-TGACCCATGACCAGGCGGAA-3’ and Ri 5’-TTCGCCTGGTCATGGGTCA-3’). The complete lipase JG3 gene sequence consists of 1081 bp from start codon ATG to the stop codon of TGA. Lipase JG3 had high similarity to another lipase from genus Alcaligenaceae which was up to 90%. However, the 3D protein visualization analysis indicated that this lipase JG3 also has the characteristic of ABC transporter protein.

Bacterial lipase holds an important role as a new source for many industrial catalysts. The investigation and understanding of the lipase-encoding gene become apparent as the key step for generating high-quality lipase as biocatalyst for many chemical reactions. In this study, bacterial lipase from Alcaligenes sp. JG3 was produced via overexpression gene method. This specific lipase was successfully overexpressed using pQE-30 vector and E. coli M15[pREP4] as host, producing His-tagged protein sized 46 kDa and was able to hydrolyze triacylglycerol from olive oil with the calculated unit activity and specific activity of 0.012 U and 1.175 U/mg respectively. The in silico investigation towards lipase JG3 revealed that it was categorized as ABC transporter protein as opposed to the conventional hydrolase family. Lastly, amino acid sequences SGSGKTT from lipase JG3 was highly conserved sequences and was predicted as the ATP-binding site but the catalytic triad of serine, histidine, and aspartate has not been solved yet.

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