微生物转化法制备γ-癸内酯的研究

发布时间：2018-05-25 02:43

  本文选题：蓖麻油 + γ-癸内酯　； 参考：《天津科技大学》2010年硕士论文

【摘要】：γ-癸内酯是香精香料行业广泛应用的一种调香原料,利用生物法生产的Y-癸内酯产品更为天然、安全,是目前的发展趋势。本文以从自然界筛选可转化蓖麻油生成Y-癸内酯的酵母菌株J1为出发菌株,利用原生质体紫外诱变技术提高γ-癸内酯的转化率,,研究了微生物二次转化法制备β-癸内酯的新工艺以及γ-癸内酯的提取及检测方法,主要结论如下。 1.从桃树林土壤及桃子表面筛选能够利用蓖麻油生成γ-癸内酯的菌种,经初筛、复筛确定酵母菌J1和J2具有分解蓖麻油的能力,与保藏的酿酒酵母、解脂假丝酵母、耐酒精酵母进行比较,酵母菌J1对蓖麻油的转化率最高,经初步鉴定,J1为子囊菌纲、酵母目、酵母科、毕赤酵母属。 2.以J1为出发菌株进行原生质体紫外诱变,确定了原生质体形成和诱变的最佳条件：菌龄16h,酶解浓度1%,酶解时间50min,酶解温度28℃,15W紫外灯,30cm处照射25min。经初筛和复筛,得到γ-癸内酯高产菌株M6,该菌株遗传稳定性良好,最适生长温度为30℃,最适生长pH为5-6。利用该菌株进行发酵,以蓖麻油为底物,Y-癸内酯产量达到1.25g/L,比出发菌株提高了28.8%。 3.确定了一次转化菌株M6的发酵培养基为：蓖麻油4%,葡萄糖15g/L,酵母浸出汁2.5g/L,蛋白胨2.5g/L,KH2PO41.2g/L,MgSO40.3g/L,Na2HPO41.0g/L,表面活性剂0.4%；培养条件为：培养温度30℃,接种量10%,装液量50mL/250mL,摇床转速200r/min,起始pH6.0。二次转化中,按8%接种量,接种一次转化12h的转化液进行二次转化试验。 4.分别以丙酮、乙酸乙酯、四氯化碳、正己烷及乙醚等不同有机溶剂对γ-癸内酯进行提取,结果表明,正己烷的萃取效果最好,含量达到1.58g/L。超临界萃取的最佳条件为：温度30℃,压力10MPa,时间1.5h,此时γ-癸内酯产量达到2.98g/L比有机溶剂萃取法提高了88.6%,转化率达到30.5%,该方法更为安全高效,利于实现天然香料的绿色生产。
[Abstract]:纬 -decolactone is a kind of seasoning raw material widely used in flavor industry. Ydecalactone produced by biological method is more natural and safe, which is the development trend at present. In this paper, the yeast strain J1, which can transform castor oil into Ydecanolactone, was selected from nature as the starting strain. By using protoplast UV mutagenesis technique to improve the conversion of 纬 -decolactone, a new process for the preparation of 尾 -decolactone by microbial secondary transformation and a method for extraction and detection of 纬 -decolactone were studied. The main conclusions are as follows. 1. The strains of producing 纬 -decolactone from peach forest soil and peach surface were screened and screened. It was confirmed that yeast J1 and J2 had the ability to decompose castor oil, and the preserved Saccharomyces cerevisiae and Candida cerevisiae were selected. The conversion rate of castor oil was the highest by yeast J1, which was identified as ascomycetes, yeasts, yeasts and Pichia pastoris. 2. The optimum conditions for protoplast formation and mutagenesis were determined by UV mutagenesis with J1 as the starting strain. The optimum conditions were as follows: the age of the protoplast was 16 h, the concentration of enzymatic hydrolysis was 1, the hydrolysis time was 50 min, and the temperature of enzymatic hydrolysis was 28 鈩，

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