Characterization of putative mannoprotein in Kluyveromyces lactis for lactase production  

作　　者：Xiuru Shen Lingtong Liao Guoqiang Zhang Jingwen Zhou Jianghua Li Guocheng Du 

机构地区：[1]Science Center for Future Foods,Jiangnan University,Wuxi,214122,China [2]National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing,Jiangnan University,1800 Lihu Road,Wuxi,Jiangsu,214122,China [3]School of Biotechnology and Key Laboratory of Industrial Biotechnology,Ministry of Education,Jiangnan University,1800 Lihu Road,Wuxi,Jiangsu,214122,China

出　　处：《Synthetic and Systems Biotechnology》2023年第1期168-175,共8页合成和系统生物技术（英文）

基　　金：supported by the National Key Research and Development Program of China [grant number 2019YFA0904900];Natural Science Foundation of Jiangsu Province [grant number BK20202002].

摘　　要：Lactase is a member of theβ-galactosidase family of enzymes that can hydrolyze lactose into galactose and glucose.However,extracellular lactase production was still restricted to the process of cell lysis.In this study,lactase-producing Kluyveromyces lactis JNXR-2101 was obtained using a rapid and sensitive method based on the fluorescent substrate 4-methylumbelliferyl-β-D-galactopyranoside.The purified enzyme was identified as a neutral lactase with an optimum pH of 9.To facilitate extracellular production of lactase,a putative mannoprotein KLLA0_E01057g of K.lactis was knocked out.It could effectively promote cell wall degradation and lactase production after lyticase treatment,which showed potential on other extracellular enzyme preparation.After optimizing the fermentation conditions,the lactase yield from mannoprotein-deficient K.lactis JNXR-2101ΔE01057g reached 159.62 U/mL in a 5-L fed-batch bioreactor.

关 键 词：Kluyveromyces lactis LACTASE SCREENING Enzymatic properties MANNOPROTEIN Fermentation optimization SECRETION 

分 类 号：TS201.3[轻工技术与工程—食品科学]