【作者】 毛涛；

【导师】 喻子牛；

【作者基本信息】 华中农业大学 ， 微生物学， 2009， 硕士

【摘要】 本论文包括两个方面的内容:1.链霉菌高产磷脂酶A₂的发酵及磷脂酶A₂在油脂脱胶和浓缩磷脂改性中的应用;2.一种新的测定他汀类物质的液相萃取方法的建立。1.在50 L发酵罐中,优化了链霉菌发酵生产磷脂酶A₂的条件。研究结果表明,通气量0.28 vvm,前16h转速300 r/min,16 h后调整转速为50 r/min,发酵周期36h,酶活达到最高,且与摇瓶发酵相比,周期缩短12 h。利用单因素和正交实验研究了磷脂酶进行菜籽油脱胶的最佳工艺,结果表明:0.065%的柠檬酸加入含磷量为145 mg/kg的菜籽油中,80℃500 r/min处理0.5 h,再按90μL/kg加入磷脂酶,在pH6.0,含水量2%,反应温度40℃的条件下反应时间3h,最终菜籽油中的磷含量小于10mg/kg,达到理想的脱胶效果。在此基础上进行中试,菜籽油通过酶处理、脱色和脱臭,达到一级食用油标准。用大豆浓缩磷脂为底物进行了酶法改性研究,结果显示:大豆浓缩磷脂的最佳水解工艺条件为:底物浓度为10%,反应温度40℃,起始pH值7.0,Ca²⁺浓度5 mM,反应时间20 h。在最佳反应条件下,释放的脂肪酸为134.7μmol/g磷脂。酶解后溶血磷脂乳化能力,乳化稳定性显著强于未改性浓缩磷脂。2.本文建立了高效液相色谱-超声波辅助的离子液体分散液相微萃取测定环境水体中微生物次级代谢药物洛伐他汀和半合成药物辛伐他汀的含量。离子液体:1-己基-3-甲基咪唑基六氟磷酸盐（[C₆MIM][PF₆]）作为萃取剂,优化了影响萃取的因素例如:起始温度,pH,盐度和冷却时间。通过液相色谱-紫外检测器测定,洛伐他汀和辛伐他汀的线性范围1-100 ng/ml,检测线分别为0.17,0.29ng/ml,精确度（RSDs,n=9）分别为:4.12%,4.52%。该方法成功的应用在测定环境水体中,在洛伐他汀和辛伐他汀在实际水样中的加标回收率分别为90.0-102.2%,80.5-112.0%。结果显示超声波辅助的离子液体分散液相微萃取在样品前处理方面提供了一种新的极具潜力的思路。更多还原

【Abstract】 This paper including two aspects:1.High-yield fermentation of phospholipase A₂ by Streptomyces and its application in the oil degumming and phospholipid modification;2.a novel dispersive liquid-phase extraction for the determination of statins.1.The fermentation conditions of Streptomyces phospholipase A₂ was optimized in the 50 L fermentor.The results showed that ventilation 0.28 vvm, rotation speed 300 rpm before the 16h,and adjusted speed to 50 r/min after 16 h,the fermentation cycle was 36 h,the highest activity was obtained,and the fermentation period was shorter.The experiments of vegetable oil degumming by phospholipase A₂ throw the design of single factor and orthogonal experimental.And the results showed that added 0.065%of citric acid in 80℃,500r/min handle 0.5 h in the early period.Then enzyme was added 90 uL/kg,pH6.0,the water content of 2%,reaction temperature 40℃,reaction time 3 h,the final phosphorus content was less than 10 mg/kg.In the pilot study,the vegetable oil through the enzyme treatment,decolorization and deodorization to reach the standard level of edible oil.Enzymatic degumming was more environmentally friendly and economic.The best hydrolysis of soybean phospholipid conditions were as follows: substrate concentration at 10%,reaction temperature 40℃,initial pH value of 7.0, Ca²⁺ concentration of 5 mM,reaction time 20 h.At the best reaction conditions,the release of fatty acids was 134.7μmol/g phospholipid.After that,lysophospholipids emulsifying capacity,emulsion stability significantly stronger than phospholipid.2.A fast and novel sample preparation procedure:ultrasound assisted ionic liquid dispersive liquid microextraction for concentration of lovastatin and simvastatin in aqueous samples was developed.An ionic liquid（[C₆MIM][PF₆]） was used as the extraction solvent,and the factors influencing the extraction efficiency such as initial temperature,the volume of ionic liquid,pH of water samples,cooling time and salt concentration were optimized.In combination with HPLC-UVD,both lovastatin and simvastatin exhibited good linear range of 1-100 ng mL^-1.The limits of detection were 0.17ng mL^-1 and 0.29ng mL^-1,respectively.Precisions of proposed method（RSDs,n=9） were 4.12%and 4.52%,respectively.This method was successfully applied in the determination of three real water samples,and good spiked recoveries were obtained at the range of 90.0-102.2%for lovastatin and 80.5-112.0%for simvastatin.These results indicated that ultrasound assisted ionic liquid dispersive liquid phase microextraction would have good application prospect in pretreatment of environmental samples.更多还原