疏水吸附分离酵母 S.Cerevisiae 中的 L-天门冬氨酸酶的研究(英文)

研究了疏水柱吸附分离工业酵母（Ｓ．Ｃｅｒｅｖｉｓｉａｅ）中的Ｌ－天门冬氨酸酶．考察了三种疏水吸附剂ＴｓｋｇｅｌＢｕｔｙ＿Ｔｏｙｏｐｅａｒｌ,ＴｓｋｇｅｌＰｈｅｎｙｌ＿Ｔｏｙｏｐｅａｒｌ和ＴｓＫｇｅｌＥｔｈｅｒ＿Ｔｏｙｏｐｅａｒｌ６５０Ｃ的吸附性能．研究表明,通过选择控制流动相的ｐＨ值和离子强度,一次吸附过程中Ｌ－天门冬氨酸酶的分离纯化纯度可提高１４倍并保持较高的活性。实验还考察了吸附等温线类型和温度等因素的影响．结果表明,酵母中分子的电荷和疏水性是疏水柱吸附的重要影响因素．     

从微生物中提取超氧化物歧化酶的研究

超氧化物歧化酶，简称ＳＯＤ（Ｓｕｐｅｒｏｘｉｄｅｄｉｓｍｕｔａｓｅ），是一种应用价值大、广泛存在于生物体细胞内的金属酶．本实验以酿酒酵母和嗜热脂肪芽孢杆菌为出发菌株，进行抗Ｈ_２Ｏ_２性能的筛选，选出耐受性好的菌株经２Ｌ发酵罐发酵后，提取到了热稳定性好的Ｃｕ，Ｚｎ－ＳＯＤ和Ｆｅ－ＳＯＤ，酶活力为３２９２和３５４７ｕ／ｍＬ，其比活力为３４５７和３０８４ｕ／ｍｇ．     

IMMOBILIZATION OF Saccharomyces Cerevisiae USING POLY（ACRYLAMIDE） GEL FOR ASYMMETRIC SYNTHESIS OF R（-）-MANDELIC ACID

In this paper, the poly(acrylamide) hydrogel used to immobilize saccharomyces cerevisiae for asymmetric synthesis of R(-)-mandelic acid was prepared with free radical ploymerization in deionized water at room temperature under nitrogen atmosphere. The influence of the composition of hydrogel, loading amount of cells and culture conditions on the asymmetric synthesis was investigated. Results show that PAAm hydrogel is a feasible carrier for immobilization of cells which is a potential alternative method to prepare enantiomerically pure R(-)-mandelic acid.     

IMMOBILIZATION OF Saccharomyces Cerevisiae USING POLY(ACRYLAMIDE)GEL FOR ASYMMETRIC SYNTHESIS OF R(-)-MANDELIC ACID

1. INTRODUCTIONPoly(acrylamide) hydrogel (PAAm gel), which is able to swell, but cannot be dissolved in the aqueous environment, is a three-dimension network with repeating hydrophilic units -CONH2. Since PAAm gel has a good biocompatibility as well as a high mechanical strength, and can be easily separated from reaction medium, PAAm gel has often been employed to immobilize enzymes and cells so as to catalyze various of chemical and biochemical reactions [1,2]. So far, biosynthesis …     

用酿酒酵母测定直接耐晒宝石蓝的急性毒性

本文的目的是建立直接耐晒宝石蓝的急性毒性微量快速分析方法。通过用基于电阻法细胞计数原理的手持式细胞计数器测定由密度约为1.0×104细胞/ml的酿酒酵母悬液20μl和系列浓度待测染料溶液130μl与2.2倍YPD液体培养基110μl所组成的体系在30℃、150 r/min恒温摇床上震荡培养6 h后的细胞数目,求算出该染料的EC50。结果显示直接耐晒宝石蓝对酿酒酵母的EC50为4995 mg/l,与文献报道的小鼠经口LC50=5 g/kg一致。表明本法可作为传统急性毒性测定的替代方法。     

Investigation of Active and Inactivated Yeast Cells by Scanning Electrochemical Impedance Microscopy

Scanning electrochemical microscopy (SECM), electrochemical impedance spectroscopy (EIS) and scanning electrochemical impedance microscopy (SEIM) were used to investigate electrochemical activity of active and inactivated yeast Saccharomyces cerevisiae cells. SEIM experiment was performed using a unique electrochemical impedance spectrometer with a fast Fourier transform (FFT‐EIS) function, which enabled simultaneously perturb/evaluate electrochemical system at 50 frequencies. This allowed very quick observing the differences between impedance spectra, which were taken every few seconds. Therefore, we were able to apply SEIM for relatively fast determination of electrochemical impedance dependence on the distance between ultramicroelectrode (UME) and surface modified by immobilized yeast cells. It was determined that electrochemical activity and ‘breathing’ (a consumption of dissolved oxygen) of yeast can be electrochemically observed when the distance between UME and surface of yeast cells is in the range from 0 μm to 25 μm. Therefore, 25 μm is the maximum distance suitable for efficient investigation of yeast cell activity when experiments are performed in FFT‐SEIM mode. Charge transfer resistance of active and inactivated yeast cells was determined using EIS. It was calculated that charge transfer resistance of active yeast cells is 1.5 times lower than that of inactivated yeast cells. Lipophilic vitamin K₃ (Vit‐K₃) and hydrophilic vitamin K₁ (Vit‐K₁) were mixtured and used as redox mediators for charge transfer from yeast cells.     

信阳米酒微生物群落组成

对 1 1家信阳市售米酒中的微生物群落组成进行了分离、鉴定 .其中酿酒酵母菌占绝对优势 ,其次是少根根霉菌和少量细菌 ,同时还含有少量有害微生物