Inoue Toyohisa, Iefuji Haruyuki, Katsumata Haruo
Nihonsakari Co., Ltd., Nishinomiya, Hyogo, Japan.
Biosci Biotechnol Biochem. 2012;76(1):60-6. doi: 10.1271/bbb.110470. Epub 2012 Jan 7.
Hygromycin B is an aminoglycoside antibiotic that inhibits protein synthesis in prokaryotes and eukaryotes. Twenty-four hygromycin B-resistants mutants were isolated from sake yeast, and were divided into three different degrees of strength according to hygromycin B resistance. Three of four hygromycin B strongly resistant mutants produced increased amounts of isoamyl acetate in sake brewing test, although isoamyl alcohol levels remained unchanged. Many hygromycin B-resistants mutants showed higher E/A ratios than K-701 in culture with koji extract medium. Strain HMR-18 produced the largest amount of isoamyl acetate, and its alcohol acetyltransferase (AATFase) activity was 1.3-fold that of K-701. DNA microarray analysis showed that many genes overexpressed in HMR-18 were involved in stress responses (heat shock, low pH, and so on) but HMR-18 showed thermo- and acid-sensitivity. It was strongly resistant to hygromycin B and another aminoglycoside antibiotic, G418.
潮霉素B是一种氨基糖苷类抗生素，可抑制原核生物和真核生物中的蛋白质合成。从清酒酵母中分离出24个潮霉素B抗性突变体，并根据潮霉素B抗性分为三种不同强度等级。在清酒酿造试验中，四个潮霉素B强抗性突变体中的三个产生了更多的乙酸异戊酯，尽管异戊醇水平保持不变。在使用曲提取物培养基培养时，许多潮霉素B抗性突变体的E/A比值高于K-701。菌株HMR-18产生的乙酸异戊酯量最大，其醇乙酰转移酶（AATFase）活性是K-701的1.3倍。DNA微阵列分析表明，在HMR-18中过表达的许多基因参与应激反应（热休克、低pH等），但HMR-18表现出热敏感性和酸敏感性。它对潮霉素B和另一种氨基糖苷类抗生素G418具有强抗性。
