培养基某些生长因子对 ZL9601 菌株产赖氨酸的影响注

以谷氨酸棒杆菌诱变株 Ｚ Ｌ９６０１ 为赖氨酸生产菌,通过摇瓶发酵培养,分析了人工培养基中３ 种必需生长因子（ 生物素、蛋氨酸、苏氨酸） 对该菌产赖氨酸的影响,并通过正交试验设计确定了３ 种生长因子的最佳配比,结果表明,３ 种生长因子可明显增高赖氨酸的产量;在人工培养基中,３ 种生长因子的最佳配比为：生物素４００μｇ／ Ｌ、蛋氨酸２５０ｍｇ／ Ｌ、苏氨酸３００ｍｇ／ Ｌ。     

培养基某些生长因子对ZL9601菌株产赖氨酸的影响

以谷氨酸棒杆菌诱变株ＺＬ９６０１为赖氨酸生产菌，通过摇瓶发酵培养，分析了人工培养基中３种必需生长因子（生物素，蛋氨酸，苏氨酸）对该菌产赖氨酸的影响并，并通过正交试验设计确定了３种生长因子的最佳配比，结果表明，３种生长因子可明显增高赖氨酸的产量，在人工培养基中，３种生长因子的最佳配比为，生物素４００μｇ／Ｌ，蛋氨酸２５０ｍｇ／Ｌ，苏氨酸３００ｍｇ／Ｌ。     

L-赖氨酸发酵生产研究进展

系统介绍了我国赖氨酸工业生产技术的发展、赖氨酸生产菌种最新研究进展：L-赖氨酸生产菌FH128菌株和L-赖氨酸高产基因工程菌的介绍和比较;对赖氨酸的几种生产技术进行了评价;分析并预测了L-赖氨酸的市场前景;对我国赖氨酸生产提出了一些建议。     

浅谈赖氨酸行业现状和发展趋势

本文概述了赖氨酸的发展、生产、品种以及应用情况，重点阐述国内外赖氨酸发展现状和发展趋势。     

乳酸发酵短杆菌中的赖氨酸代谢控制发酵

以本室选育的赖氨酸产生菌AL 0 39为出发菌株 ,以亚硝基胍诱变 ,筛选到一株氟丙酮酸敏感型突变株FP 0 94,其赖氨酸产量比出发菌株提高 37.5 %。进而研究了生物素、醋酸钙对该菌产赖氨酸的影响。     

利用酒糟固态发酵多维多酶高赖氨酸饲料的研究

赖氨酸是一种动物自身不能合成的,第一限制性氨基酸,在食品、医药及饲料等应用方面,都有相当重要的实用意义,含有赖氨酸的强化饲料,可加速畜禽的生长,而且提高肉质、缩短育令期,提高产肉、产蛋及产奶率,因此在饲料中,赖氨酸的含量至关重要,我们选用赖氨酸产生菌...     

陶瓷膜在赖氨酸提取中的应用

介绍了陶瓷膜的分离设备与技术,以及在赖氨酸分离提取中的应用,分析研究了陶瓷膜在生产运行中出现的问题与解决措施。     

赖氨酸发酵过程监控系统的设计

针对赖氨酸生产厂家的设备现状和对赖氨酸发酵的生产要求,结合新仪器仪表,采用组态王开发设计了赖氨酸发酵过程监控系统,包括赖氨酸发酵数据显示系统和赖氨酸发酵过程上位机监控系统。实际应用表明:该监控系统能够对赖氨酸发酵过程重要参数实现实时监控和集中管理,且监控界面直观、形象,准确迅速地反映生产现场的真实情况,对于降低劳动强度,实现赖氨酸产量和质量的提高等都奠定了基础。     

赖氨酸脱羧酶分子改造及其催化合成戊二胺

1,5-戊二胺(戊二胺)具有良好的生物活性,广泛应用在农业、医药以及工业等领域。赖氨酸脱羧酶可以催化L-赖氨酸生产戊二胺,为了提高赖氨酸脱羧酶催化合成戊二胺的效率,首先在大肠杆菌中克隆表达了粘质沙雷氏菌来源的赖氨酸脱羧酶(SmcadA)。生化特征表明,SmcadA最适催化pH为6.0,最适催化温度约为40℃。随后对SmcadA的第348位氨基酸进行了突变研究,筛选获得了催化效率显著提高的突变体Gly348Ala,主要原因是该突变导致蛋白中氨基酸残基和底物之间相互作用的氢键数增加,从而影响其催化效率。最后,对重组菌株细胞进行了戊二胺合成研究,催化反应25 h,含有突变体Gly348Ala的重组菌细胞可以催化合成218.2 g/L戊二胺,野生型SmcadA重组菌仅能催化合成159.2 g/L戊二胺。该研究结果为工业化酶催化合成戊二胺提供了借鉴。     

赖氨酸硫酸盐结块问题探析

论述了赖氨酸硫酸盐生产及存储过程中结块产生的原因及其影响因素,并简述了缓解赖氨酸硫酸盐结块的有效方法.     

微生物碱性蛋白酶研究进展

本文主要综述了微生物碱性蛋白酶在国内外的应用研究和现状,对微生物碱性蛋白酶的产生菌,碱性蛋白酶的应用、基因结构及性质,高产工程茵的选育技术等方面的研究进展进行了概述,并根据当前应用研究状况对微生物碱性蛋白酶在今后的发展进行了展望.     

糖化酶及糖化酶基因在酿酒酵母中表达的研究进展

介绍了糖化酶的性质和结构,同时介绍了糖化酶基因引入酿酒酵母中构建酿酒酵母工程菌和糖化酶高效分泌到酿酒酵母胞外的研究进展;展望了糖化酶今后的研究方向以及应用前景.     

Gene expression in wheat beer yeast strains and the synthesis of acetate esters

The synthesis of aroma compounds represents one of the most important parameters in beer production. Although it has been a historical topic of research, exactly how aroma components are formed has yet to be fully explained. Moreover, all of the research that has been published on yeast strains is focused on lagers and ales. Wheat beer yeast strains have not been the focus of aroma and flavour research. In this study, five different wheat beer yeasts were analysed to determine their capacity for producing acetate esters. In this study, the most commonly used wheat beer yeast strains for the production of German‐style wheat beer were analysed. This involved measuring the level of expression of the alcohol acetyl transferase genes ATF1, ATF2 and IAH1 over a period of 4 days (during primary fermentation) and plotting the data to observe the development of expression of the genes over time. Results confirmed their capacity to form acetate esters and showed a distinct correlation with increasing expression of the gene ATF1. However, the findings also indicated that gene expression in different yeast strains can vary considerably during fermentation. Copyright © 2016 The Institute of Brewing & Distilling     

丝状真菌基因敲除技术研究进展

丝状真菌在自然界分布广泛，与人类的生产、生活密切相关。近年来，对于其基因功能的研究取得了较大的进展，一系列转化和基因操作技术已在不同的丝状真菌中得到运用。许多对于工业、农业和医药卫生具有重要意义的丝状真菌已经完成或正在进行全基因组序列测定。作者简述了丝状真菌基因敲除的历史，重点介绍了近年来基因敲除技术在丝状真菌研究中的进展，并对冀在丝状真菌基因功能研究、工业菌株改良等方面进行了展望。     

食品级乳酸工程菌的研究进展

简要概述了乳酸菌控制表达体系的研究现状,总结了食品级乳酸工程菌的研究进展,提出了今后的研究方向及其应用前景。     

Efficient PCR-based gene disruption in Saccharomyces strains using intergenic primers

Gene disruptions are a vital tool for understanding Saccharomyces cerevisiae gene function. An arrayed library of gene disruption strains has been produced by a consortium of yeast laboratories; however their use is limited to a single genetic background. Since the yeast research community works with several different strain backgrounds, disruption libraries in other common laboratory strains are desirable. We have developed simple PCR-based methods that allow transfer of gene disruptions from the S288C-derived strain library into any Saccharomyces strain. One method transfers the unique sequence tags that flank each of the disrupted genes and replaces the kanamycin resistance marker with a recyclable URA3 gene from Kluyveromyces lactis. All gene-specific PCR amplifications for this method are performed using a pre-existing set of primers that are commercially available. We have also extended this PCR technique to develop a second general gene disruption method suitable for any transformable strain of Saccharomyces.     

JCM和NBRC益生菌资源保藏状况概述

详细分析了日本两个权威菌种保藏管理中心JCM(Japan collection of microorganisms)和NBRC(NITE biological resource center)的益生菌资源保存状况,所介绍益生菌资源符合我国益生菌相关法规规定的乳杆菌、双歧杆菌和嗜热链球菌3类共11个种或亚种的益生菌菌种名单,重点介绍了菌种资源的多样性和相关分类学和应用信息。同时还介绍了这两个权威菌种保藏机构的便捷的数据库检索系统、完善的菌种质量控制体系以及先进的数据库和菌种库管理方法,以期对我国益生菌资源的保藏管理以及研究和开发提供借鉴。     

‘Marker Swap’ Plasmids: Convenient Tools for Budding Yeast Molecular Genetics

One-step gene disruption constructs for disruption of HIS3, LEU2, TRP1 or URA3 with each of the other three markers have been constructed. All of these constructs have been tested and found to effectively convert markers either in gene disruptions or on plasmids. The ‘swapped’ strains allow the unambiguous genetic analysis of synthetic phenotypes with multiple genes, even if the original gene disruptions were made with the same marker. They also allow introduction of multiple plasmids in a single transformant, even if the original plasmids had the same marker, and allow transformation of plasmids into strains containing gene disruptions made with the same marker that is on the plasmids. These ‘marker-swap’ plasmids therefore eliminate the need for much subcloning to change markers. Marker-swapped alleles are acceptably stable mitotically and meiotically for most applications.© 1997 John Wiley & Sons, Ltd.     

野生菌株特征功能基因过表达在食品领域中的研究进展

微生物菌种影响着发酵工业的发展,菌种的质量优劣从根本上决定了发酵食品质量的好坏。近年来,科学家已经从自然环境筛选到很多具有特征功能的野生菌株,并以基因工程方法过表达其功能基因,加强功能特性,以期获得工业化生产的工程菌。该综述阐述了基因过表达技术在食品领域的研究进展,重点概述了该技术在增加物质产量和增强微生物适应环境能力等方面的突出作用,讨论了工程菌的安全性及转基因食品检测技术,展望该技术在改造野生菌株能力方面的美好发展前景,旨在为今后基因工程菌的构建研究提供思路,为深入探究工程菌与发酵食品改善之间的关系奠定基础。     

Physiology of mutants with reduced expression of plasma membrane H+-ATPase

Two mutations containing insertions and deletions in the promoter in the plasma membrane H+-ATPase gene (PMA1) of Saccharomyces cerevisiae have been introduced into the genome by homologous recombination, replacing the wild-type gene. The resulting strains have 15 and 23% of the wild-type ATPase content. Decreased levels of ATPase correlate with decreased rates of proton efflux and decreased uptake rates of amino acids, methylamine, hygromycin B and tetraphenylphosphonium. This supports a central role of the enzyme in yeast bioenergetics. However, the final accumulation gradient of tetraphenylphosphonium is not affected by the mutations and that of methylamine and 2-aminoisobutyric acid is only decreased in the most extreme mutant. Apparently, kinetic constraints seem to prevent the equilibration of yeast active transports with the electrochemical proton gradient. As expected from their transport defects, the ATPase-deficient mutants are more resistant to hygromycin B and more sensitive to acidification than wild-type yeast. Mutant cells are very elongated, suggesting a structural role of the ATPase in the yeast surface.