Detection and molecular characterization of lipase-producing bacteria

Abstract

Background Lipase is a type of hydrolytic enzyme that has several applications and industrial efforts. Lipases are used as biological catalysts to manufacture products such as food ingredients and applied in making fine chemicals. The type of lipase produced from microbes, mainly from bacteria and fungi, represents the most widely used class of enzymes in biotechnological applications and organic chemistry. Microbial enzymes are also more stable than their corresponding plant and animal enzymes, and their production is more convenient and safer, which makes them more important in commercial uses. The oily environment of vegetable oil-processing factories, industrial wastes, soil contaminated with oil, and diesel fuel-polluted soil provides a suitable habitat for lipase-producing microorganisms. Objective This study aims to detect new strains of lipase-producing bacteria from diverse sources and different areas in Jeddah, Saudi Arabia. Furthermore, the detected bacterial strains have been identified based on morphological, biochemical, and molecular characterization. The plasmid profile of some isolated bacterial strains has been detected. Materials and methods A total of 36 soil samples contaminated with fuel and engine oil were collected from different areas in Jeddah, Saudi Arabia. Tween 20 medium was used to detect the lipolytic activity of the bacterial strains. The isolated bacteria in this study were identified by morphological and biochemical tests and 16SrRNA. Results and discussion Results showed that 53 isolates were positive and able to produce lipase, and 15 isolates have been selected as strong lipase-producing bacteria. The sequences were submitted to the NCBI GenBank under accession numbers, accession numbers, ON360988.1 for Acinetobacter sp. (FS5), ON360990.1 for Alcaligenes faecalis (FS8), ON360991.1 for Acinetobacter baumannii (FS9), ON360992.1 for Bacillus tropicus (FS10), ON360993.1 for A. baumannii (FS11), ON360994.1 for Sphingomonas aeria (FS15), and ON360996.1 for A. baumannii (FS17). Plasmids were isolated from selected strains that showed lipase production using a plasmid-isolation miniprep. Results indicated that isolates FS6 and FS15 have no plasmids, whereas FS8 has one plasmid (≈1295.5 bp). Furthermore, isolates FS10 and FS11 have two plasmids (≈1539.3 and 1295.5 bp). In addition, isolate FS9 has three plasmids (≈1539.3, 1295.5, and 417.7 bp). The isolates showed strong lipase activity and could be good sources for the production of lipase.