Biotechnology Bulletin ›› 2015, Vol. 31 ›› Issue (1): 144-150.doi: 10.13560/j.cnki.biotech.bull.1985.2015.01.022

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Screening and Identification of High-yield Thermostable Lipase Producing Microorganisms

Li Yang, Cai Haiying, Zhao Minjie, Zhang Hui, Feng Fengqin   

  1. Zhejiang University,College of Biosystems Engineering and Food Science,Fuli Institute of Food Science,Zhejiang Key Laboratory for Agro-Food ProcessingZhejiang R & D Center for Food Technology and EquipmentHangzhou 310058)
  • Received:2014-06-25 Online:2015-01-09 Published:2015-01-10

Abstract: Two strains of microorganisms(J2 and J3)with a high-yield lipase producing ability had been screened from dumplings’ steamer cushions, and identified as two variants of Aureobasidium sp. according to morphological observation and 26S rRNA gene(26S rDNA)sequencing. After being incubated at 30℃, 200 r/min for 3-5 d, the lipase activities of their fermentation supernatant were 10.61 U/mL and 14.43 U/mL, respectively, measured by spectrophotometry with p-nitrophenol palmitate(p-NPP)as a substrate. The investigation of physicochemical properties of the produced lipases(Lip2 and Lip3)showed that the optimum catalyzing temperature of Lip2 is 50℃ and there is no significant activity loss after being incubated at 50℃ for 5 h, while the optimum catalyzing temperature of Lip3 is 60℃ and there is no activity loss after being incubated at 40℃ for 5 h, but only 42.19% of lipase activity remained when incubated at 50℃ for 5 h. The results indicated that the lipases produced by strain J2 and J3 have good thermal stability and high optimal reaction temperature.

Key words: lipase, thermostability, Aureobasidium sp., 26S rDNA, growth curve