A strain isolated from seawater samples in the Chuckchi Sea and exhibiting extracellular lipolytic activity was identified using 16S rRNA gene sequence analysis as Psychrobacter sp. ArcL13. The lipolytic enzyme exhibited cold-active properties and high hydrolytic activity toward p-nitrophenyl caprylate (C8), p-nitrophenyl decanoate (C10), and sunflower oil. Statistical optimization of the medium components was performed to enhance the production of cold-active extracellular lipolytic activity. Glucose, yeast extract (YE), and NaCl were selected as the main efficient nutrient sources. Fed-batch fermentation using optimized medium with concentrated YE as the main feeding material showed a maximum lipolytic activity of 10.7 U/mL, which was a 21-fold increase in production over unoptimized flask culture conditions. The information obtained in the present study could prove applicable to the production of cold-active lipase on a large scale.
Keywords: arctic bacterium; fed-batch fermentation; lipolytic activity; psychrophile; statistical optimization.