A novel mono- and diacylglycerol lipase highly expressed in Pichia pastoris and its application for food emulsifier preparation

• A novel mono-and diacylglycerol lipase (MDL) gene was highly expressed in Pichia pastoris and named as Lipase GH1.
• Lipase GH1 is a glycosylated protein and stable under alkaline conditions.
• Lipase GH1 exhibited the potential application for preparation food emulsifiers.

A mono- and diacylglycerol lipase (MDL) was cloned from Penicillium cyclopium and expressed in Pichia pastoris strain GS115. The recombinant enzyme was named Lipase GH1. High cell density fermentation was performed by culture in a 7.5-L fermenter using BSMG medium, in which the phosphate in basal salt medium was replaced by sodium glycerophosphate (Na2GP). The maximal lipase activity detected was 18,000 U per mL, and total protein content in the fermentation supernatant was 3.94 g per L. The activity of the liquid enzyme remained stable under alkaline conditions at 4 °C for 6 months and was 50% after one year. Lipase GH1 was used for the synthesis of mono- and diacylglycerols (MAGs and DAGs), which are commonly used emulsifiers for industrial applications. A conversion rate of 84% after 24 h of reaction was obtained using glycerol/oleic acid molar ratio 11:1, water content 1.5 wt%, enzyme dosage 80 U per g, and reaction temperature 35 °C. Lipase GH1 was more efficient for the synthesis of MAGs and DAGs than was Lipase G50 (a similar, commercially available lipase derived from Penicillium camemberti) when oleic acid was used as an acyl donor. Lipase GH1 has potential for food emulsifier preparation.