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。     

食窦魏斯氏菌NCU034005与柠檬明串珠菌NCU027003对泡菜代谢物及风味的影响

在灭菌后的泡菜原材料中分别接种食窦魏斯氏菌NCU034005与柠檬明串珠菌NCU027003,室温纯种发酵7d,期间检测泡菜液中挥发性物质与非挥发性物质(葡萄糖、有机酸、氨基酸等)、pH、风味物质香气活度值。结果表明:食窦魏斯氏菌NCU034005与柠檬明串珠菌NCU027003纯种发酵泡菜中pH不同程度下降,两株乳酸菌对碳水化合物、有机酸与氨基酸的代谢能力不同;主成分分析表明食窦魏斯氏菌NCU034005与柠檬明串珠菌NCU027003纯种发酵泡菜中的代谢物与风味存在显著差异,且有自身的代表性标志代谢物与风味因子。食窦魏斯氏菌NCU034005与柠檬明串珠菌NCU027003对泡菜代谢物与风味有显著影响。     

传统四川泡菜发酵过程中明串珠菌的分离鉴定

分别以红皮萝卜、卷心菜、豇豆为原料,用自然发酵法制作了三种四川泡菜。对三种泡菜发酵过程中的明串珠菌进行分离,主要得到四种不同形态的菌株,将其分别命名为:MC-1、MC-2、MC-13、J-5,其中J-5为豇豆泡菜特有,其余为三种泡菜共有。采用生理生化结合16SrDNA序列鉴定对分离的菌株进行鉴定,依次鉴定为:乳明串珠菌(L.lactis)、肠膜明串株菌葡聚糖亚种(L.mesenteroides subsp.dextranicum)、柠檬明串珠菌(L.citreum)、假肠膜明串珠菌(L.pseudomesenteroide)。对发酵过程中明串珠菌动态分析表明:L.lactis、L.mesenteroides subsp.dextranicum为三种泡菜中的主要优势明串珠菌;L.citreum在发酵第2~4d出现后很快又消失;L.pseudomesenteroide在豇豆发酵的第3~9d比较活跃;泡菜发酵到第11d,泡菜水中所有的L.lactis都消失。     

肠膜明串珠菌发酵对四川泡菜中有机酸生成的影响

四川泡菜是我国具有代表性的传统发酵食品。有机酸是衡量四川泡菜发酵程度和品质的重要指标。为研究肠膜明串珠菌发酵对四川泡菜中有机酸生成的影响,在传统四川泡菜制作工艺的基础上,以自然和接种肠膜明串珠菌2种方式发酵四川泡菜,对发酵过程中微生物数量、总酸及有机酸含量进行了测定。结果表明,接种肠膜明串珠菌发酵的四川泡菜与自然发酵相比,其菌落优势大于自然发酵组,总酸优先达到平衡,柠檬酸、酒石酸含量高于自然发酵组;接种发酵组中苹果酸、柠檬酸、抗坏血酸、酒石酸、乳酸含量在发酵20 d后的含量分别为2.76、0.94、0.07、0.17、49.22 mg/mL;接种肠膜明串珠菌发酵提高了四川泡菜中有机酸的含量,缩短了发酵周期,为四川泡菜新型乳酸菌发酵剂的研发提供理论依据,为四川泡菜工业化生产奠定基础。     

酸泡菜发酵过程中乳酸菌区系的研究

在几种酸泡菜的发酵过程中,分离、鉴定出肠膜明串珠菌,葡聚糖明串珠菌、小片球菌、植物乳杆菌、短乳杆菌、发酵乳杆菌、棒状乳杆菌等乳酸菌种类。明串珠菌、片球菌一般在发酵前期出现.乳杆菌则在发酵的中后期占优势,其中以植物乳杆菌最常见。     

香辛料对传统发酵泡菜中细菌群落结构及理化特性的影响研究

该研究基于高通量测序技术研究香辛料对传统发酵泡菜细菌群落结构的影响，并监测发酵过程中pH、总酸和亚硝酸盐含量的变化。结果表明，未添加香辛料的泡菜（P组）中主要优势菌属为肠杆菌（46.34%）、明串珠菌（18.25%）、乳球菌（9.76%）、假单胞菌（4.22%）等，添加香辛料的泡菜（PS组）中明串珠菌（70.26%）成为绝对优势菌；主坐标分析（PCoA）结果表明，两组泡菜的菌群结构差异极显著（P<0.01）,PS组中各样本聚集程度高；与P组相比，PS组泡菜有更快的产酸速率，且显著降低了亚硝酸盐的含量（P<0.05）;Spearman相关性分析结果表明，P组中Lactobacillus KR107058.1.1463、Vibrio KF799889.1.1509、Pseudomonas EU539857.1.1397、Pseudomonas AF534216.1.1462和Enterobacteriaceae KC555526.1.1442均与亚硝酸盐含量呈极显著正相关（P<0.01）,PS组中来自明串珠菌属的三个特征序列与亚硝酸盐含量呈极显著负相关（P<0.01...     

传统中韩泡菜乳酸菌菌相分析与风味物质组成的比较

通过对传统中韩泡菜的发酵原料与工艺,乳酸菌菌相和风味物质组成进行比较,分析了传统中韩泡菜发酵过程中乳酸菌菌相的生态演替和风味物质组成。传统中国泡菜发酵过程中的优势乳酸菌为明串珠菌Leuconostoc、乳杆菌Lactobacillus、片球菌Pediococcus和肠球菌Enterococcus,产品的主体风味物质包括有机酸类、醇类和酯类。传统韩国泡菜发酵过程的优势乳酸菌为明串珠菌Leuconostoc、乳杆菌Lactobacillus、乳球菌Lactococcus和魏斯氏菌Weissella,其主体风味物质为含硫化合物。传统中韩泡菜发酵过程中的乳酸菌菌群演变和主体风味物质组成都存在较大差异。     

自然发酵泡菜中乳酸菌的分离及特性研究(二)

本文将继续研究蔗糖浓度对L1-明串珠菌属 (Leuconostoc)和L2 -乳杆菌属 (Lactobacillus)的影响 ,以及他们在泡菜制作中的应用。若在泡菜制作时接种L1、L2 或L1和L2 的混菌 ,均可缩短泡菜的成熟时间 ,但风味不及自然发酵的泡菜     

肠膜明串珠菌发酵对四川泡菜品质的影响

四川泡菜是我国具有代表性的传统发酵食品。传统泡菜的制作方式多为自然发酵、具有发酵时间长、发酵条件不易控制、产品质量难以保障等弊端。为进一步研究接种发酵对泡菜品质的影响,在传统四川泡菜制作工艺的基础上,以自然和接种肠膜明串珠菌2种方式发酵四川泡菜,对发酵过程中p H、总酸、亚硝酸盐、质构参数进行测定,最后进行成品感官评价。实验结果显示,与自然发酵相比接种发酵的泡菜p H下降速度和总酸含量上升速度快,亚硝酸盐含量较低,质构特性优,感官评价综合得分高。因此,接种肠膜明串珠菌发酵四川泡菜可以缩短发酵周期,加强泡菜食用安全性,改善风味,提高泡菜的品质。     

明串珠菌筛选与分类的研究进展

明串珠菌存在于蔬菜、饲料和多种发酵食品等各种植物材料中,在各种乳制品中有应用,因此近年来国内对它的研究开始活跃。文中论述了明串珠菌的生存环境、筛选方法、鉴定手段和分类,为分类学研究提供参考。     

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.     

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。     

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.     

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.     

假肠膜明串珠菌产细菌素复配抑菌液的筛选及保鲜效果研究

目的 筛选出最优的假肠膜明串珠菌（Leuconostoc mesenteroides, LM）产细菌素复配抑菌液,同时探究抑菌液对冷鲜鸡肉的保鲜效果。方法 以冷鲜鸡肉及其主要腐败菌为研究对象,研究假肠膜明串珠菌产细菌素的最佳生长周期,并利用假肠膜明串珠菌产细菌素抑菌液、乳酸链球菌素抑菌液、假肠膜明串珠菌产细菌素和柚子精油复配抑菌抑菌液以及假肠膜明串珠菌产细菌素和茶多酚复配抑菌液分别浸泡鸡肉,从肉的pH、汁液流失率、色度、菌落总数、挥发性盐基氮（total volatile basic nitrogen, TVB-N）、感官评定等评价其对鸡肉冷藏品质的影响,比较以上几种抑菌液对鸡肉的保鲜效果,筛选出最佳的抑菌液。结果 假肠膜明串珠菌产细菌素的生长周期与其抑菌活性呈一定正相关。实验组的4种抑菌液均能延缓冷鲜鸡肉劣变,但1.5%假肠膜明串珠菌产细菌素抑菌液、40 mg/L乳酸链球菌素抑菌液对冷鲜鸡肉保鲜效果有限。而1.5%假肠膜明串珠菌产细菌素和0.2%茶多酚复配抑菌液、1.5%假肠膜明串珠菌产细菌素和10%柚子精油复配抑菌液的保鲜效果较好,尤其在以1.5%假肠膜明串珠菌产细菌素和10%柚子精油复配抑菌液液处理时,对冷鲜鸡肉的保鲜作用最强。结论 1.5%假肠膜明串珠菌产细菌素和10%柚子精油复配抑菌液对冷鲜鸡肉具有最佳的保鲜效果。     

自然发酵豆酱中明串珠菌的分离鉴定

分离筛选传统发酵豆酱中的明串珠菌,研究其益生特性。以采集自东北6 个地区的56 份自然发酵豆酱为研究对象,用稀释涂布平板方法对明串珠菌进行分离筛选,然后对疑似菌株进行形态学特征、生理生化特征和16S rRNA基因序列进行分析,确定菌株种属序列,然后对鉴定得到的明串菌株进行耐酸耐胆盐性能比较。结果表明：从56?份豆酱样品中共分离到118?株疑似乳酸菌,从中得到6?株明串珠菌,鉴定3?株为乳酸明串珠菌,3?株为肠膜明串珠菌肠膜亚种。综合比较6?株明串珠菌耐酸耐胆盐性,发现菌株FX6益生性最好,在pH?3.0环境培养3?h后存活率可达85.16%,在含0.3 g/100 mL胆盐环境培养6?h后存活率高达96.07%。因此,菌株FX6可用于进一步科研以及工业应用,其在豆酱发酵过程的作用机理仍需深入研究。     

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.