Lim Mi-Hyeon, Lee Ok-Hee, Chin Jong-Eon, Ko Hyun-Mi, Kim Il-Chul, Lee Hwanghee Blaise, Im Suhn-Young, Bai Suk
Department of Biological Sciences, College of Natural Sciences, Chonnam National University, Gwangju 500-757, South Korea.
Biotechnol Lett. 2008 Dec;30(12):2125-30. doi: 10.1007/s10529-008-9799-x. Epub 2008 Jul 16.
Phytase liberates inorganic phosphate from phytic acid (myo-inositol hexakisphosphate) which is the major phosphate reserve in plant-derived foods and feeds. An industrial strain of Saccharomyces cerevisiae expressing the Debaryomyces castellii phytase gene (phytDc) and D. occidentalis alpha-amylase gene (AMY) was developed. The phytDc and AMY genes were constitutively expressed under the ADC1 promoter in S. cerevisiae by using the delta-integration system, which contains DNA derived exclusively from yeast. The recombinant industrial strain secreted both phytase and alpha-amylase for the efficient degradation of phytic acid and starch as main components of plant seeds. This new strain hydrolyzed 90% of 0.5% (w/v) sodium phytate within 5 days of growth and utilized 100% of 2% (w/v) starch within 48 h simultaneously.
植酸酶可从植酸（肌醇六磷酸）中释放出无机磷酸盐，植酸是植物性食品和饲料中主要的磷储备形式。构建了一株表达德巴利酵母植酸酶基因（phytDc）和西方酵母α-淀粉酶基因（AMY）的工业酿酒酵母菌株。通过使用仅包含酵母来源DNA的δ整合系统，phytDc和AMY基因在酿酒酵母的ADC1启动子下组成型表达。该重组工业菌株分泌植酸酶和α-淀粉酶，可有效降解作为植物种子主要成分的植酸和淀粉。该新菌株在生长5天内可水解90%的0.5%（w/v）植酸钠，同时在48小时内可利用100%的2%（w/v）淀粉。
