假丝酵母脂肪酶Lipase AY 30G催化红花油水解研究

在无溶剂体系中,对假丝酵母脂肪酶Lipase AY 30G水解油脂的性能进行了研究,确定了这种脂肪酶的最适反应条件：温度35℃,缓冲溶液为0.05mol/L K2HPO4/KH2PO4,pH6.0,加酶量为m（酶）：m（油）=0.2%-1%,添加剂CaCl2加入量为0.1%;在优化条件下反应4h的水解率可达96.8%。     

脂肪酶水解油脂

本文介绍了脂肪酶水解油脂制脂肪酸和甘油的新技术，评述解脂用脂肪酶的酶种选择、工艺要点及特色以及脂肪酶水解油脂的国内外进展，并对这项生物酶工程技术在我国应用的前景提出见解。     

固定化脂肪酶催化天然油脂水解和甘油解

概述了国外用于工业化生产的效水解、甘油解油脂的微生物脂肪酶和固定化酶的各种载体，讨论了固定化脂肪酸论油脂水解和甘油解的影响因素，介绍了三种固定脂肪酶生物反应器。     

微乳液体系中脂肪酶催化油脂水解合成单甘酯

在微乳液体系中脂肪酶催化棕榈油水解可合成单甘酯,最佳条件下,单甘酯的含量为１２．９１％,此时单甘酯的得率为８１．７％。     

蚕丝固定化脂肪酶催化性能研究

研究了蚕丝固定化脂肪酶对橄榄油的催化水解特性，发现在５５℃，ｐＨ＝８．２的条件下，固定化脂肪酶活性最高。底物浓度高达５７％（Ｖ／Ｖ）时，仍无抑制，适宜的搅拌速度是４００～４５０ｒｐｍ。在上述条件下，固定化脂肪酶间歇水解橄榄油，重复使用１０次水解率从９６．５％降至５３．０％，间歇水解猪油的半衰期约为２６０ｈ。     

微乳液体系中脂肪酶催化合成酯反应的动力学研究

不同的微乳液体系中,脂肪酶催化合成酯的反应受脂肪酶浓度、正己酸浓度、正丁醇浓度的影响。结果表明:反应初始速率V0随正己酸的初始浓度的增大而增大,随正丁醇的初始浓度的增大而减小;当十二烷基聚葡糖苷(C12G1.50)量较小,C12G1.5的浓度对反应初始速率V0影响不大;C12G1.5量较大时,反应初始速率V0随C12G1.50浓度增大而增大。固定C12G1.50的浓度不变,当正己酸浓度较低时,反应初始速率V0随正丁醇浓度增大而减小;当正己酸浓度较高时,反应初始速率V0随正丁醇浓度增大而增大。     

脂肪酶水解植物油及动力学参数测定

以酯解理论为基础,通过均匀设计法研究游离酶水解植物油的最佳工艺条件。试验结果表明:游离酶最佳催化条件为pH9.6、33℃、底物浓度25％,其动力学参数Vm和Km值分别为5.56(μmol/ml·min)和6.2×10~(-2)(V/V)。     

Lipase Catalyzed Transesterification of Unsaturated Lipids in a Microemulsion

A series of triglycerides having varying degrees of unsaturation of the acyl groups has been transesterified with stearic acid. It is shown that the position of the double bonds, not the degree of unsaturation, is the decisive factor in the rate of reaction. A A-6 double bond, which is present in petroselinic acid and ylinolenic acid, prevents reaction. Unsymmetrical triglycerides containing only one acyl group with δ-6 unsaturation reacts regiospecifically with the A-6 acyl group facing away from the enzyme. γ-Linolenic acid can be incorporated into an unhindered triglyceride through lipase catalyzed transesterification, indicating that the active site can in fact accommodate a δ-6 fatty acid, although not the corresponding triglyceride.     

Hydrolysis of Olive Oil with Immobilized Lipase in a Tapered Column Reactor

Lipase was immobilized in ion exchange resin and then used in the hydrolysis of olive oil to produce fatty acids and glycerol. The time course of hydrolysis of olive oil was investigated in a stirred tank reactor using both of the free and immobilized lipases to find the yield of activity of immobilized enzyme. Continuous hydrolysis of olive oil was also carried out in a tapered column reactor and a cylindrical column reactor with a bottom ID of 10 mm at different upward flow rates. It can be known from experimental results that the degree of hydrolysis of olive oil in the tapered column reactor is moderately better than that in the cylindrical column reactor, the pressure drop in the tapered column reactor is much smaller than that in the cylindrical column reactor.     

脂肪酶催化食用废油制备生物柴油

利用脂肪酶为催化剂,食用废油与甲醇反应,制备生物柴油,最佳酯化反应条件为反应温度50℃、脂肪酶催化剂用量为原料量的3%、甲醇与食用废油体积比为3∶1、共溶剂丁酮量为甲醇量的1/6、pH=7,反应时间4h,生物柴油产率可达到78%,对产品的各项指标测定,均达到GB/T20828-2007要求,指标并与0#石化柴油相接近。     

Lipase Catalyzed Synthesis of Medium-chain Biodiesel from Cinnamonum camphora Seed Oil

The non-edible camphor tree seed oil was extracted and catalyzed by immobilized lipase for biodiesel production. The oil yield from camphor tree seeds reached 35.2% of seed weight by twice microwave-assisted extractions. Gas chromatography showed that free fatty acid content in camphor tree seed oil was 1.88%, and the main fatty acids were capric acid (53.4%) and lauric acid (38.7%). With immobilized lipase Candida sp. 99–125 as catalyst, several important factors for reaction conditions were examined through orthogonal experiments. The optimum conditions were obtained: water content and enzyme loading were both 15% with a molar ratio of 1:3.5 (oil/ethanol), and the process of alcoholysis was in nine steps at 40 °C for 24 h, with agitation at 170 r·min^− 1. As a result, the medium-chain biodiesel yield was 93.5%. The immobilized lipase was stable when it was used repeatedly for 210 h.     

酶催化餐饮业废油脂生产生物柴油的研究

研究了利用餐饮业废油脂和甲醇,在无溶剂系统中通过脂肪酶的转酯作用来生产生物柴油.结果表明,醇油摩尔比为3∶1时甲醇转化率只能达到48%左右,醇油摩尔比低于1∶1时甲醇转化率能达到95%以上,采用分批添加法,甲醇总转化率可以明显提高到80%以上.反应体系的最适初始水活度应控制在0.54～0.75之间,随着反应温度的升高,酯交换反应的速度加快,但酶失活率也随之增大.     

表面活性剂包衣Candida rugosa脂肪酶在无溶剂下油水两相体系中催化橄榄油水解

The surfactant-coated Candida rugosa lipase was used as catalyst for hydrolysis of olive oil in two-phase system consisting of olive oil and phosphate buffer without organic solvent. For both the coated and native lipases,the optimal buffer/oil volume ratio of 1.0, aqueous pH 6.8 and reaction temperature 30℃ were determined. The maximum activity of the coated lipase was ca 1.3 times than that of the native lipase. The half-life of the coated lipase in olive oil and the native lipase in phosphate buffer was ca 9 h and 12 h, and the final residual activity was 27% and 20% of their initial values, respectively. The final substrate conversion by the coated lipase was ca 20% higher than that of the native lipase.     

脂肪酶催化碳-碳键形成反应的研究

脂肪酶的多功能性广泛应用于有机合成反应中.本文综述了脂肪酶催化碳-碳键形成反应进展,例如:Michael反应、Mannich反应、Knoevenagel反应、Diels-alder反应、Henry反应等.     

Interesterification of Lard and Soybean Oil Blends Catalyzed by Immobilized Lipase in a Continuous Packed Bed Reactor

Structured lipids (SL), formulated by blends of lard and soybean oil in different ratios, were subjected to continuous enzymatic interesterification catalyzed by an immobilized lipase from Thermomyces lanuginosus (Lipozyme TL IM) in a continuous packed bed reactor. The original and interesterified blends were examined for fatty acid and triacylglycerol composition, regiospecific distribution, and solid fat content. Blends of lard and soybean oil in the proportions 80:20 and 70:30 (w/w), respectively, demonstrated a fatty acid composition, and proportions of polyunsaturated/saturated fatty acids (PUFA/SFA) and monounsaturated/polyunsaturated fatty acids (MUFA/PUFA), that are appropriate for the formulation of pediatric products. These same blends were suited for this purpose after interesterification because their sn-2 positions were occupied by saturated fatty acids (52.5 and 45.4%, respectively), while unsaturated fatty acids predominantly occupied sn-1,3 positions, akin to human milk fat. Interesterification caused rearrangement of triacylglycerol species.     

微乳作为清洗介质的应用(英)

微乳明确地存在于由水、油、表面活性剂和辅助表面活性剂及电解质组成的多元体系的相区中,具有超低界面张力,对亲水物和亲油物有很高增溶力。因此微乳在织物去污中作介质可将有机溶剂增溶作用与传统的湿洗特性结合起来。     

有机相中壳聚糖-海藻酸固定化脂酶的特性

研究了壳聚糖 海藻酸固定化脂酶在有机相反应中的稳定性与活性。考察了凝胶时间、壳聚糖浓度及壳聚糖分子质量对固定化脂酶包埋率与活性的影响 ,确定了适宜 pH值与批反应时间。同时讨论了溶剂极性和操作时间对固定化酶稳定性的影响。测定了固定化脂酶水解橄榄油反应的动力学参数。结果表明 ,壳聚糖 海藻酸聚电解质膜可提高固定化酶的包埋率与稳定性