变性梯度凝胶电泳(DGGE)技术在食品微生物研究中的应用

变性梯度凝胶电泳(DGGE)是一种分析微生物区系的分子指纹技术.概述DGGE的基本原理、发展和应用现状,着重阐述该技术在评价发酵食品的细菌群落组成和动态变化、区分发酵食品、控制食品质量、检测食源性致病微生物等食品微生物研究领域中的应用,进一步展望了DGGE技术在食品研究领域的应用前景.     

传统发酵食品中的微生物及其代谢作用

传统发酵食品体系是功能性食品微生物的重要来源。多样的微生物构成了发酵食品的复杂微生态环境,其代谢作用与发酵制品的品质和风味密切相关,许多功能性微生物也赋予了发酵制品特殊的活性。但与此同时,微生物代谢的过程中也伴随有害物质的产生,传统发酵食品的安全问题也成了人们的关注焦点。因此,探究发酵食品中微生物的群落组成和代谢作用对发酵食品的质量控制和新功能的发掘都具有重要意义。随着分子生物学技术的发展,传统发酵食品微生物的群落组成逐步得到解析,微生物在发酵环境中的作用也越来越多地被研究。本文对大豆发酵食品、食醋、发酵酒类、普洱茶、红曲等传统发酵食品中的微生物及其代谢作用进行了综述,并对发酵食品中功能性微生物的研究方向进行了展望。     

元基因组学在传统发酵食品微生态中的应用

元基因组学是分子生物学技术应用于微生物生态学研究形成的一个概念,通过直接从环境样品中提取全部微生物的DNA,并利用基因组学策略研究环境样品所包含的全部微生物的遗传组成及其群落功能。目前,该技术已经广泛应用于传统发酵食品发酵过程中微生物的多样性以及功能研究。我国传统发酵食品历史悠久,且各自具有独特的生产工艺,发酵过程涉及的微生物种类较多,赋予了传统发酵食品特有的风味与功能。随着传统发酵食品生产的产业化以及对食品安全的高度重视,传统发酵食品发酵过程中微生物的多样性和功能成为研究的热点,综述了元基因组分析技术在传统发酵食品微生态研究中的应用进展,并对今后传统发酵食品微生物的研究趋势进行展望。     

微生物分子生态学技术在传统发酵食品行业中的应用研究进展

微生物分子生态学作为分子生物学与微生物生态学交叉而形成的学科,在传统发酵食品行业中的应用还处于起步阶段。本文从分子生态学实验技术角度,综述了目前一些传统发酵食品行业生产过程中微生物群落结构、多样性及其功能相关性的研究进展,并探讨了分子微生态学技术在传统发酵行业的应用前景。     

传统发酵食品中微生物多样性和群落结构动态变化研究进展

传统发酵食品制作和食用历史悠久,其中蕴藏了丰富的微生物资源。随着分子生物学技术的不断发展,可从基因水平上全面揭示传统发酵食品中微生物的多样性和群落结构的动态变化,阐明其发酵机理,对今后传统发酵食品的工业化、标准化生产和益生菌的开发利用具有极其重要的意义。     

传统发酵过程微生物互作研究进展

在传统发酵过程中,丰富的营养物质、开放的发酵环境和历史传承的发酵工艺促成丰富多样且相对稳定的微生物群落发酵体系。这些微生物的生长繁殖和相互作用控制发酵过程,同时产生丰富的营养成分和独特的风味物质,是传统发酵精髓所在。这些微生物相互作用类型丰富,包括真菌与真菌、真菌与细菌、细菌与细菌之间的互利共生、偏利共生和相互竞争等。近些年来,随着高通量DNA测序技术和组学分析技术的广泛应用,对传统发酵过程的微生物相互作用的认识得到进一步加强。本文从不同传统发酵食品入手,总结了传统发酵过程中的微生物群落结构及其相互作用,着重阐述典型性微生物相互作用中的分子机制,有助于研究和认识发酵过程中微生物相互作用方式及其机理。     

发酵食品中微生物多样性研究方法进展

发酵食品中的微生物是食品发酵体系中与发酵食品的品质和风味有着密切联系的组成成分.对发酵食品中微生物的多样性及其所扮演角色进行调查,能为改进传统食品发酵工艺、探究发酵食品风味形成机理等方面提供技术支持.文中介绍了目前研究发酵食品中微生物多样性的多种方法,并分析比较了各种技术方法的优缺点.     

高通量测序技术在传统发酵食品微生物群落中的应用研究

传统发酵食品风味独特,营养丰富,历史悠久,生产方式多采用自然接种,部分食品的生产工艺已有数千年的历史,其最终质量与发酵过程中存在的多种微生物密切相关。研究表明,运用现代分子生物学技术,可从基因水平上揭示微生物的多样性和群落结构的动态变化,系统阐明其发酵机理。该文综述高通量测序技术在传统发酵食品微生物群落中的应用研究,对聚合酶链式反应-变性梯度凝胶电泳（PCR-DGGE）、实时荧光定量聚合酶链式反应（RT-FQPCR）、宏基因组、宏转录组测序等研究方法的原理、操作方法及其研究成果进行了总结,并对各分析技术优缺点进行了比较,旨在为传统发酵食品的微生物群落研究提供参考。     

中国传统发酵食品微生物多样性研究进展

中国传统发酵食品由于微生物的发酵作用改善产品的营养价值并赋予产品独特的风味,成为人们饮食中重要的组成部分.文章主要阐述了我国传统发酵食品常用的微生物检测技术,并对中国传统发酵食品微生物多样性的研究进展进行了综述,旨在为筛选优良发酵菌株,调控中国传统发酵食品的发酵过程提供理论参考.     

传统发酵食品中微生物多样性与风味形成之间关系及机制的研究进展

传统发酵食品在发酵过程中微生物群落结构复杂多变,风味物质代谢途径多样。微生物被誉为发酵食品的“灵魂”,能够通过多种代谢途径影响发酵食品的感官、营养和功能特性,与风味的形成紧密相关。解析微生物与风味化合物间的作用关系,有利于探明潜在风味功能菌群和控制发酵食品风味特性。本文重点综述了白酒、发酵醋、发酵蔬菜和发酵畜产品等传统发酵食品中微生物多样性与风味形成之间的相关性,简要阐述了核心微生物的风味代谢机制,以期为传统发酵食品的品质提升提供参考。     

蛋白质水解度测定方法综述

对目前国内外常用的蛋白质水解度测定方法进行了综述，其中pH—state方法是通过滴定水解过程中释放的质子测定DH；OPA、TNBS及国内常用的水合茚三酮和甲醛等测定方法是利用游离氨基的反应测定DH。     

SEROLOGIC IDENTIFICATION OF SPECIES OF ORIGIN OF SAUSAGE MEATS

SUMMARY: A partially purified immunoglobulin G (lgG) solution prepared from the serum of species to be tested was heated to the specifications for sausages. The resulting supernatant fluid was decanted and the precipitate washed with saline and used to immunize rabbits. The supernatant fluid was used to sensitize tanned sheep red blood cells. The immune serum was rendered monospecific by absorptions with heterologous, heated lgG precipitates. A sample of monospecific immune serum was absorbed with a washed homogenate of sausage. Aliquots of the monospecific immune serum, both untreated and sausage absorbed, were tested with cells sensitized with the homologous heated lgG supematant fluid. A significant reduction of titer by sausage absorption indicated that the sausages contained the meat homologous to the immune serum.     

聚多元羧酸盐的合成及应用

研究了聚多元羧酸盐的合成方法及反应机理,将其应用于洗涤剂和PVC制品中分别代替三聚磷酸钠和邻苯二甲酸二丁酯,证明有良好效果。     

BASIS OF STABILITY OF AMINE SALTS OF LINOLEIC ACID

SUMMARY— The mechanism and generality of the known stabilization against autoxidation conferred on linoleic acid by certain basic amino acids, such as lysine and arginine, was investigated. Basic amino acids were the only class of compounds found to confer the effect. However, the smallest basic amino acid, 2,3-diaminopropionic acid, was not effective, nor was αβω-diaminc acid, 3,6-diaminohexanoic acid, although a simple isomer of lysine. The stabilization was observed only in the solid phase. Inclusion of sodium chloride in the solid matrix was deleterious to the effect. A large number of physical and chemical observations were made and correlated but it has not been possible to draw detailed conclusions about the mechanism of stabilization, nor can a detailed structure of the stabilized complex be suggested. The cause of the phenomenon appears to be closely associated with the physical arrangement of the ions in the crystal lattice.     

STABILITY OF AQUEOUS EMULSIONS OF THE ESSENTIAL OIL OF HOPS

Hop oil emulsions prepared from different varieties of hops have been found to exhibit enhanced physical stability on the addition of blends of the emulsifiers Span 20/Tween 80 or Span 60/Tween 60. Examination of the particle size and volume distributions of an emulsion by use of a Coulter Counter was found to be an excellent method of monitoring its stability. An indication as to the relative efficiency of emulsifiers can be obtained from Coulter Counter measurements on hop oil emulsions after storage for 4 days. The use of an ultracentrifuge provies a rapid means of testing emulsion stability and hence the effectiveness of emulsion stabilizers.     

百年风尚

一场流光溢彩、赏心悦目的展览,一段百年风尚演进的传奇旅程,一次东西方文化艺术的完美对话。2013年9月13日,“博萃臻艺一中西方珍宝艺术展”在辽宁省博物馆举行了隆重的开幕仪式,法兰西共和国驻华大使白林女士、辽宁省文物局局长丁辉先生、辽宁省博物馆馆长马宝杰先生、卡地亚全球总裁兼首席执行官邓阁仕先生、卡地亚区域行政总裁（北亚洲）陆慧全先生、卡地亚中国区首席执行官陆意斯先生、辽宁省文物店总经理张春鹰先生,以及众多文化界与文博界的贵宾齐聚一堂,共同见证了这场文化艺术盛事。     

ANALYTICAL CHARACTERIZATION OF THE PRODUCTS OF NONENZYMATIC GLYCOSYLATION OF LYSOZYME

The quantitative analysis of the reaction products of the water activity dependent nonenzymatic glycosylation of lysozyme was not straightforward. Difficulties arose in the determination of the number of bound glucose molecules because glycosylation leads to glucose mediated protein aggregation, and the likely presence of a mixture of relatively labile Schiff-base intermediates, and the more stable ketoamine products generated by Amadori rearrangement. Polyacrylamide gel electrophoresis was used to monitor protein aggregation; periodate oxidation, nuclear magnetic resonance (NMR), and oxalic acid hydrolysis combined with HPLC, emerged as the most promising methods to quantitate the degree of glycosylation. Possible interpretations are advanced to explain the apparent discrepancies in degree of glycosylation suggested by the different analytical methods evaluated.     

EFFECTS OF TYPES OF FAT AND OF RATES AND TEMPERATURES OF COMMINUTION ON DISPERSION OF LIPIDS IN FRANKFURTERS

ABSTRACT— The effect of time, temperature and rpm of comminution of emulsions was determined on the dispersion of approximately 25% of beef fat, pork fat or cottonseed oil in frankfurters. The numbers of lipid particles 5 μ or less in diameter increased in frankfurters containing either beef or pork fat as comminution was continued to higher temperatures, with pork fat dispersed more thoroughly. Fat tended to separate from frankfurters containing beef fat in particles 200 μ or more in diameter. In contrast, no specific degree of dispersion of particles 5 μ or less in diameter consistently indicated emulsion stability, or its lack. Increased rpm during comminution produced an increased dispersion of beef or pork fat. Under the same conditions pork fat was dispersed more finely than beef fat. Dispersion of cottonseed oil produced finely dispersed particles beyond the resolution of light microscopy, as was confirmed by electron microscopy which showed a substantial number of particles to be less than 1 μ in diameter.     

DEVELOPMENT OF CHAINS OF CELLS OF SACCHAROMYCES CEREVISIAE DURING FERMENTATION

The lengths of chains of cells of Saccharomyces cerevisiae were studied during fermentation. Pitching yeast generally contained about half of the total number of cells as two-celled chains. The chain lengths varied during the subsequent fermentation and the variations were characteristic of the strain. Electronic counting assessments of chain length were unreliable.     

矩阵乘积的行式,列式

给出了ｍ×ｍ矩阵与ｍ×ｎ矩阵的行（列）式的表达式．若Ａ＝ａ１１ａ１２…ａ１ｍａ２１ａ２２…ａ２ｍ……ａｍ１ａｍ２…ａｍｍＢ＝ｂ１１ｂ１２…ｂ１ｎｂ２１ｂ２２…ｂ２ｎ……ｂｍ１ｂｍ２…ｂｍｎ分别是ｍ×ｍ，ｍ×ｎ矩阵，则｜Ａ｜｜Ｂ｜＝｜ＡＢ｜＋∑ｉ１＜ｉ２＜…＜ｉｔｊ１＜ｊ２＜…＜ｊｔ１≤ｔ≤ｍｎ－ｔ≥ｍＮＢｉ１ｉ２…ｉｔｊ１ｊ２…ｊｔＮＡＢ１…ｍ（－１）ｓｔ＋１ｊｔ＋１…（－１）ｓｎｊｎ其中ｉ１，ｉ２，…，ｉｔ是１，２，…，ｍ中ｔ个数码；ｊ１，ｊ２，…，ｊｔ，ｊｔ＋１，…，ｊｎ是１，２，…，ｎ的一个排列；ｓｒ＝π（ｊ１，ｊ２，…，ｊｔ，ｊｒ）（ｒ＝１，２，…，ｎ）是排列ｊ１，ｊ２，…，ｊｔ，ｊｒ的反序数．