發(fā)布時(shí)間：2018-05-25 02:43

  本文選題：蓖麻油 + γ-癸內(nèi)酯　； 參考：《天津科技大學(xué)》2010年碩士論文

【摘要】：γ-癸內(nèi)酯是香精香料行業(yè)廣泛應(yīng)用的一種調(diào)香原料,利用生物法生產(chǎn)的Y-癸內(nèi)酯產(chǎn)品更為天然、安全,是目前的發(fā)展趨勢(shì)。本文以從自然界篩選可轉(zhuǎn)化蓖麻油生成Y-癸內(nèi)酯的酵母菌株J1為出發(fā)菌株,利用原生質(zhì)體紫外誘變技術(shù)提高γ-癸內(nèi)酯的轉(zhuǎn)化率,,研究了微生物二次轉(zhuǎn)化法制備β-癸內(nèi)酯的新工藝以及γ-癸內(nèi)酯的提取及檢測(cè)方法,主要結(jié)論如下。 1.從桃樹(shù)林土壤及桃子表面篩選能夠利用蓖麻油生成γ-癸內(nèi)酯的菌種,經(jīng)初篩、復(fù)篩確定酵母菌J1和J2具有分解蓖麻油的能力,與保藏的釀酒酵母、解脂假絲酵母、耐酒精酵母進(jìn)行比較,酵母菌J1對(duì)蓖麻油的轉(zhuǎn)化率最高,經(jīng)初步鑒定,J1為子囊菌綱、酵母目、酵母科、畢赤酵母屬。 2.以J1為出發(fā)菌株進(jìn)行原生質(zhì)體紫外誘變,確定了原生質(zhì)體形成和誘變的最佳條件：菌齡16h,酶解濃度1%,酶解時(shí)間50min,酶解溫度28℃,15W紫外燈,30cm處照射25min。經(jīng)初篩和復(fù)篩,得到γ-癸內(nèi)酯高產(chǎn)菌株M6,該菌株遺傳穩(wěn)定性良好,最適生長(zhǎng)溫度為30℃,最適生長(zhǎng)pH為5-6。利用該菌株進(jìn)行發(fā)酵,以蓖麻油為底物,Y-癸內(nèi)酯產(chǎn)量達(dá)到1.25g/L,比出發(fā)菌株提高了28.8%。 3.確定了一次轉(zhuǎn)化菌株M6的發(fā)酵培養(yǎng)基為：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,表面活性劑0.4%；培養(yǎng)條件為：培養(yǎng)溫度30℃,接種量10%,裝液量50mL/250mL,搖床轉(zhuǎn)速200r/min,起始pH6.0。二次轉(zhuǎn)化中,按8%接種量,接種一次轉(zhuǎn)化12h的轉(zhuǎn)化液進(jìn)行二次轉(zhuǎn)化試驗(yàn)。 4.分別以丙酮、乙酸乙酯、四氯化碳、正己烷及乙醚等不同有機(jī)溶劑對(duì)γ-癸內(nèi)酯進(jìn)行提取,結(jié)果表明,正己烷的萃取效果最好,含量達(dá)到1.58g/L。超臨界萃取的最佳條件為：溫度30℃,壓力10MPa,時(shí)間1.5h,此時(shí)γ-癸內(nèi)酯產(chǎn)量達(dá)到2.98g/L比有機(jī)溶劑萃取法提高了88.6%,轉(zhuǎn)化率達(dá)到30.5%,該方法更為安全高效,利于實(shí)現(xiàn)天然香料的綠色生產(chǎn)。
[Abstract]:緯 -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 緯 -decolactone, a new process for the preparation of 尾 -decolactone by microbial secondary transformation and a method for extraction and detection of 緯 -decolactone were studied. The main conclusions are as follows. 1. The strains of producing 緯 -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，

本文編號(hào)：1931749