Extracellular cold active lipase from the psychrotrophic Halomonas sp. BRI 8 isolated from the Antarctic sea water

Abstract

An extracellular cold active lipase-producing psychrotrophic bacterium (BRI 8) was isolated from the Antarctic sea water sample. The 16s rRNA sequence study revealed that the isolate belongs to the genus Halomonas (929 bp). The present paper reports optimization of fermentation conditions for production of lipase (EC 3.1.1.3) from Halomonas sp. BRI 8. Highest lipase production was observed in the medium containing olive oil and peptone. The optimum pH and temperature for enzyme catalysis were 7.0 and 10°C respectively. The enzyme was relatively more stable in acidic pH range and retained 50% activity when incubated at 30°C for 1 h. The enzyme was stable in various organic solvents and showed more than 100% activity in presence of isoamyl alcohol. Significant enzyme activity was also observed in the presence of metal ions and detergents. The molecular mass of partially purified lipase was found to be around 66 kD.

Keywords

• Halomonas
• Antarctic
• cold active lipase
• optimization
• stability