明串珠菌的基因研究进展

明串珠菌是韩国泡菜、德国泡菜和腌菜等发酵蔬菜中的优势细菌,保持产品的质量中起着重要作用,在各种乳制品中也有其的应用,因此近年来在内地对它的研究开始活跃。该文论述明串珠菌的有用蛋白质基因的克隆与异源表达、对明串珠菌的遗传转化和染色体改造、基因组等方面的研究进展,为今后的明串珠菌基因研究提供借鉴。     

明串珠菌的碳代谢调控研究进展

明串珠菌是韩国泡菜、德国泡菜和腌菜等发酵蔬菜中的优势细菌,保持产品的质量中起着重要作用,在各种乳制品中也有它的应用,因此近年来在内地对其的研究开始活跃.为明串珠菌的碳代谢调控研究提供第一手资料,该文综述了明串珠菌的碳代谢途径、发酵调控和基因表达调控.     

明串珠菌发酵产甘露醇的研究进展

明串珠菌是韩国泡菜、德国泡菜和腌菜等发酵蔬菜中的优势细菌,保持产品的质量中起着重要作用,在各种乳制品中也有其的应用,因此近年来在内地对其的研究开始活跃。明串珠菌的发酵产甘露醇实现大规模工业化的潜力非常大,因此丰要论述了明串珠菌的甘露醇转化及相关代谢、发酵产甘露醇的研究。     

明串珠菌在食品行业的研究进展

基于明串珠菌的一般特性,对明串珠菌在发酵制品等传统食品和功能食品中的研究进展情况进行介绍,概述了其做为有益菌的应用价值,同时从来源、危害、检测和控制方面综述了制糖工业中明串珠菌的防控研究情况。     

明串珠菌在食品行业的研究进展

基于明串珠菌的一般特性,对明串珠菌在发酵制品等传统食品和功能食品中的研究进展情况进行介绍,概述了其做为有益菌的应用价值。同时从来源、危害、检测和控制方面综述了制糖工业中明串珠菌的防控研究情况。     

肠膜明串珠菌的研究和应用进展

肠膜明串珠菌是乳酸菌中的明串珠菌属的重要菌种。研究证实,肠膜明串珠菌能发酵糖类产生多种酸和醇,具有高产酸能力、抗氧化能力和拮抗致病菌等能力。目前肠膜明串珠菌已被广泛应用于风味剂、血浆代用品,还有望成为新型微生态制剂。     

乳制品中明串珠菌的分离鉴定及其生物学特性研究

对内蒙古自治区呼伦贝尔市牧区98个乳样中的明串珠菌进行了分离及生物学特性研究。共分离到明串珠菌3株，分别属于乳明串珠菌(EW21)，肠膜明串珠菌葡聚糖亚种(EW24—2)和肠膜明串珠菌肠膜亚种(CB8—1)。它们均可在pH=4．8的环境中生长，且菌株EW24—2和CB8—1可利用蔗糖生成葡聚糖。     

发酵香肠中分离纯化的三株乳酸菌产酸特性研究

为了研究从发酵香肠中分离纯化的3株乳酸菌粪肠球菌(Enterococcus faecalis)、戊糖片球菌(Pediococcus pentosaceus)和肠膜明串珠菌(Leuconostoc mesenteroides)的产酸性能,对这3株菌在不同pH、温度、NaCl、NaNO2条件下的生长情况及产酸情况进行了测定。研究结果显示:这3株菌中,肠膜明串珠菌和戊糖片球菌的生长特性较好;粪肠球菌的生长特性虽不如肠膜明串珠菌和戊糖片球菌,但产酸能力最好,戊糖片球菌耐盐性最好、肠膜明串珠菌耐亚硝酸盐的特性最好;在不同温度和pH条件的测试中,肠膜明串珠菌的生长能力最好,粪肠球菌次之。这3株乳酸菌在发酵肉制品中均产生乳酸。总之,这3株菌均具有用于发酵制备乳酸的能力。     

碳酸饮料絮凝物的微生物分离及其耐酸性研究

从碳酸饮料的絮凝物中分离出的微生物,经过形态学特征及生理生化特性分析,获得了3株明串珠菌属菌株,鉴定为:假肠膜明串珠菌1株,肠膜明串珠菌葡聚糖亚种2株。对3株菌株进行了pH3.0的耐酸性研究,其中3#呈现出最强的耐酸性和碳酸饮料的适应性。     

低温生产高活性右旋糖苷蔗糖酶的明串珠菌的筛选

明串珠菌是异型发酵乳酸菌的一种,主要作用于蔬菜发酵食品的发酵初期,能够代谢生成CO2和多种风味化合物,是占有重要地位的发酵剂菌种之一。明串珠菌在蔗糖诱导下分泌右旋糖酐蔗糖酶,此酶分解蔗糖生成的葡萄糖基,转移到异麦芽糖等受体中生成低聚糖。为了提高蔬菜发酵食品中低聚糖生成量,实验从蔬菜发酵食品中筛选了低温生产高活性右旋糖酐蔗糖酶的明串珠菌,随后对分离菌株进行了鉴定及发酵特性研究。结果所筛选4个菌株均为肠膜明串珠菌,在低温下显示了很高的右旋糖酐蔗糖酶活性。这些明串珠菌菌株应用到发酵食品将会有助于提高发酵食品的感官质量和功能性。     

Classification of ropy slime-producing lactic acid bacteria based on DNA-DNA homology, and identification of Lactobacillus sake and Leuconostoc amelibiosum as dominant spoilage organisms in meat products.

The classification of lactic acid bacteria able to cause ropy slime on vacuum-packed cooked meat products was carried out based on DNA-DNA homology. The ropy slime-producing lactobacilli were identified as strains of Lactobacillus sake and the ropy slime-producing leuconostocs, such as Leuconostoc amelibiosum and Leuconostoc mesenteroides.     

Safety assessment of dairy microorganisms: the Leuconostoc genus

Although Leuconostoc genus is "generally recognized as safe" (GRAS), a few clinically human infections cases by this microorganism have been reported in the literature, leading to their classification as opportunistic pathogens. However, these reported cases concern only severe immunodepressed patients, and none direct relations have yet been proven between Leuconostoc isolation and human diseases. Moreover, no cases of infections have been directly linked to the consumption of fermented food. Considering the long history of use of Leuconostoc in dairy industry, and their poor incidence in human infections cases, this bacterial genus may be reasonably considered as " safe " for its use in fermented dairy products.     

Detection of Leuconostoc strains at a meat processing plant using polymerase chain reaction

To simplify the labor-intensive conventional routine testing of samples to detect Leuconostoc at a meat processing plant, we developed polymerase chain reaction (PCR) primers specific for Leuconostoc from 16S rRNA gene sequences. These primers did not detect other common lactic acid bacteria such as Lactobacillus plantarum, Lact. sake, Lact. fermentum, Lact. acidophilus and Weissella viridescens. PCR with this primer detected all Leuconostoc species tested (Leu. mesenteroides subsp. mesenteroides, Leu. pseudomesenteroides, Leu. carnosum, Leu. lactic, Leu. citreum, Leu. amelibiosum, Leu. gelidum), except for Leu. fallax, and no other lactic acid bacteria on agarose gel electrophoresis. The method could identify areas contaminated with Leuconostoc in a large-scale industrial meat processing plant. Of 69 samples analyzed, 34 were positive for Leuconostoc according to the conventional culture method (isolation of LAB producing dextran) and PCR, whereas 29 were negative according to both. Six samples were culture-negative but positive by PCR. No false negative results were generated by PCR. The method is rapid and simple, is useful for routinely monitoring areas contaminated with Leuconostoc in meat processing plants, and could help to prevent the spoilage of meat products.     

Spoilage of value-added, high-oxygen modified-atmosphere packaged raw beef steaks by Leuconostoc gasicomitatum and Leuconostoc gelidum

Moisture-enhancing and marinating of meats are commonly used by the meat industry to add value to raw, retail products. Recently in Finland, certain value-added beef steak products have proven to be unusually susceptible to microbial spoilage leading to untoward quality deteriorations during producer-defined shelf-life. This study was conducted to evaluate the role of lactic acid bacteria (LAB) in the premature spoilage of value-added beef packaged under high-oxygen modified atmospheres. Spoilage was characterised by green discolouration and a buttery off-odour. The predominant LAB in eight packages of spoiled, marinated or moisture-enhanced beef steaks were identified by reference to a 16 and 23S rRNA gene restriction fragment length polymorphism pattern (ribotype) database. Leuconostoc gasicomitatum, Leuconostoc gelidum, Lactobacillus algidus, Lactobacillus sakei and Carnobacterium divergens were found to predominate in the LAB populations at numbers above 10(8) CFU/g. Inoculation of moisture-enhanced steaks with LAB strains and strain mixtures originating from the spoiled products demonstrated the spoilage potential of L. gasicomitatum and L. gelidum isolates. These two species produced green surface discolouration and buttery off-odours similar to these found in the spoiled, commercial products.     

Evaluation of lactic acid bacteria,isolated from lightly preserved fish products,as starter cultures for new fish-based food products

Lactic acid bacteria suitable for fish fermentation were selected and their capacity as starter cultures in fish raw material was evaluated. Of 23 strains of lactic acid bacteria which were isolated from lightly preserved herring products and identified by the Biolog system mainly as Lactobacillus and Leuconostoc spp., three strains, which grew well at 5–10°C in the presence of food preservatives, were chosen for evaluation. Qualitative changes in minced fish, inoculated with lactic acid bacteria, and stored at 10°C for 7 weeks, were examined by organoleptic, bacteriological and chemical methods, and were found to be strongly strain specific. Inhibition of the competitive flora was more significant in the samples inoculated with Lactobacillus plantarum and Lactobacillus mesenteroides than in others. The best organoleptic and chemical results were obtained with Leuconostoc mesenteroides; this strain looks promising as a starter culture for fish fermentation and for the development of new fish products, which organoleptically resemble meat products.     

发酵剂在乳品中应用的影响因素及协同发酵的研究进展

发酵剂因在乳品工业中扮演着重要角色而被广泛关注。为了更加科学、高效、经济的使用乳品发酵剂,需要对其有更深的认知。因此本文对乳品发酵剂的常见类型（乳杆菌属、链球菌属、双歧杆菌属、明串珠菌属及乳球菌属）及益生作用,影响发酵的因素（菌种的选择、噬菌体及抗生素）及协同发酵（共生、偏利）进行了概述,以期对其在乳品中的应用提供一定的参考。