干芥菜接种发酵发酵剂优化

分别研究乳酸菌发酵剂菌株肠膜明串珠菌、植物乳杆菌和戊糖片球菌的发酵特性,并对各菌株的生长情况、产酸能力、耐盐性、耐温性及pH值适应性进行测定。结果表明,3种乳酸菌组合发酵的干芥菜总酸、氨基酸态氮、挥发酯含量和感官评分最高,此时肠膜明串珠菌∶植物乳杆菌∶戊糖片球菌=2∶3∶2,发酵产品总酸含量为1.07%,氨基酸态氮含量为0.16%,挥发酯含量为2.48 g/kg,感官评分为91.0分,品质较好,为接种发酵干芥菜的最优发酵剂。     

西梅发酵乳酸菌的筛选、鉴定及其抗氧化特性研究

采用传统平板划线的方式分离纯化西梅原浆中的乳酸菌。通过溴甲酚紫MRS固体培养基和西梅汁固体培养初步筛选出5株产酸性能较好,适合西梅发酵的乳酸菌种,经生理、生化鉴定和16S rDNA分子生物学鉴定,最终确定4株菌为屎肠球菌,1株菌为肠膜明串珠菌。测定5株乳酸菌在MRS肉汤中的生长性能、产酸性能以及菌种自身抗氧化性能,结果肠膜明串珠菌E2在MRS肉汤中生长迅速且产酸性能较好,肠膜明串珠菌E2和屎肠球菌C2的完整乳酸菌细胞悬液具有较好的抗氧化能力。以总酚含量、DPPH自由基清除率、ABTS自由基清除率为指标,对比5种乳酸菌在西梅浆中的发酵性能,结果肠膜明串珠菌E2更适合西梅浆的发酵,屎肠球菌C2次之。     

玉米酸汤面自然发酵过程中乳酸菌的分离鉴定及特性研究

对玉米酸汤面自然发酵过程中不同时期的乳酸菌进行分离鉴定及特性研究,从中分离出5株乳酸细菌,利用现代分析技术与经典分类法对其进行了系统的细菌学鉴定.鉴定结果表明,这5株乳酸菌分别为:戊糖片球菌、乳酸乳球菌、植物乳球菌、肠膜明串珠菌、德氏乳杆菌.并测定了发酵过程中乳酸菌的数量变化及各发酵阶段的主导菌相,最后得出适宜的发酵条件.     

赤峰地区酸菜中乳酸菌的筛选与初步鉴定

从传统发酵的酸菜汁中分离筛选到10株产酸能力较高的乳酸菌.通过形态特征、菌落特征和生理生化特征进行分析可知,其中3株为肠膜明串珠菌葡聚糖亚种,3株为植物乳杆菌,3株为短乳杆菌,l株为乳酸片球菌.并对其中4株代表菌株做了生长曲线和产酸量分析.     

渝黔地区传统酸肉发酵过程中微生物区系研究

目的:对渝黔地区传统酸肉微生物种群进行研究。方法:采用不同的选择培养基对微生物进行分离鉴定和计数。结果:从中分离出乳酸菌、酵母菌、葡萄球菌和微球菌,未发现霉菌。乳酸菌优势菌群主要是片球菌属和乳杆菌属,鉴定12株乳酸菌分别为乳酸链球菌、肠膜明串珠菌、类肠膜明串珠菌、植物乳杆菌、米酒乳杆菌、乳酸片球菌、戊糖片球菌、约氏乳杆菌、嗜盐片球菌和啤酒片球菌;优势菌株戊糖片球菌、植物乳杆菌贯穿整个发酵过程。葡萄球菌主要是表皮葡萄球菌、腐生葡萄球菌、木糖葡萄球菌和肉葡萄球菌,其中木糖葡萄球菌为主要发酵菌株。酵母菌主要为汉逊酵母属、接合酵母属、毕赤氏酵母和德巴利酵母属等,鲁氏接合酵母为优势发酵菌株。结论:优势微生物是酸肉风味品质形成的基础,本研究可为高效天然肉制品发酵剂的研究提供生物资源。     

四川传统发酵香肠中几株优势乳酸菌的分离鉴定

为了获得产乳酸菌种,以制备用于制作聚乳酸的乳酸分子,以四川传统发酵香肠为原料,对其中的优势乳酸菌进行分离、纯化,并利用Biolog微生物鉴定系统的生理生化鉴定,结合16SrDNA分子生物学鉴定,对所得乳酸菌的种属进行了鉴定。结果显示,从发酵香肠中分离得到3株优势乳酸菌,经生理生化及分子生物学鉴定发现,所得3株乳酸菌分别为粪肠球菌(Enterococcus faecalis)、戊糖片球菌(Pediococcus pentosaceus)和肠膜明串珠菌(Leuconostoc mesenteroides)。该结果为制备生物源乳酸单体提供了菌种,并为开发肉制品发酵剂及传统肉制品加工提供了参考。     

酸白菜腌制过程中优势乳酸菌及菌群演替规律研究

以陕西杨凌地区大白菜为原料,切碎,添加2.5%食盐,在22 ℃进行半厌氧自然发酵酸泡菜。发酵过程中在不同时间取泡菜液,测定泡菜pH值、乳酸菌落和菌落总数变化,分离鉴定优势乳酸菌株,检测酸白菜微生物多样性,探究酸白菜腌制过程中菌群的演替变化规律。结果表明:泡菜自然发酵,从第0天到第7天,pH值从初始的6.0降到4.2,乳酸菌数由4.65 lg(CFU/mL)增至7.86 lg(CFU/mL),菌落总数由9.11 lg(CFU/mL)减至8.65 lg(CFU/mL)。在不同发酵阶段共分离鉴定出27株乳酸菌,分别为10株明串珠菌,7株魏斯氏菌,4株乳酸乳球菌,4株弯曲乳杆菌和2株戊糖片球菌。泡菜发酵起始优势乳酸菌种属为魏斯氏菌,发酵中期优势乳酸菌逐渐变成乳酸乳球菌,肠膜明串珠菌演替成优势乳酸菌。整个泡菜发酵阶段异型乳酸发酵菌种占据主导地位,发酵中、后期(5 d后)同型乳酸发酵菌种参与泡菜发酵。     

开菲尔(Kefir)酸牛乳酒中乳酸菌分离及发酵性能测定

对自制的开菲尔酸牛乳酒进行分离得到16株乳酸菌,通过显微镜观察及生理生化特性研究,结果为肠膜明串珠菌乳脂亚种两株,乳酸乳球菌乳酸亚种2株,乳酸乳球菌乳脂亚种2株,粪肠球菌1株,瑞士乳杆菌3株,德氏乳杆菌保加利亚亚种2株,嗜酸乳杆菌4株;经发酵性能测定,筛选出2株乳酸球菌LC2、LC6和3株乳酸杆菌LB3、LB4、LB8发酵活力较高、发酵乳组织状态及风味较好,可作为Kefir酸牛乳酒纯培养发酵剂乳酸菌的备选菌株.     

湘西传统酸鱼中乳酸菌的分离及特性研究

对从湘西传统酸鱼4个不同发酵阶段分离的196株乳酸菌种类进行了研究,分离出的乳酸菌主要包括植物乳杆菌、戊糖片球菌、食品乳杆菌、明串珠菌、肠球菌及干酪乳杆菌等,并且这些乳酸菌在发酵过程中呈现出一种动态的变化进程。同时对分离到的乳酸菌进行了一系列的生理生化试验;产酸速率实验,耐食盐、耐亚硝盐实验,耐酸及耐胆盐实验,氨基酸脱羧酶实验以及抑菌实验,选育出具有较好的发酵剂潜力的3株植物乳杆菌和1株戊糖片球菌。     

几种乳酸菌的生理特性研究

本文研究了参与酸泡菜发酵生产的几种代表性乳酸菌:植物乳杆菌、肠膜明串珠菌、发酵乳杆菌和小片球菌的发酵产酸曲线和pH 曲线,并探讨了氯化钠与葡萄糖浓度对乳酸菌的生长与心酵产酸量的影响,以及乳酸菌的生长温度范围与耐乙醇的能力。     

Diversity of lactic acid bacteria isolated from AOC Salers cheese

The objective of this work was to describe the diversity of lactic acid bacteria in traditional raw milk Salers cheeses at the species and strain levels. The characterization of 381 strains isolated during ripening and various strain collections was investigated using physiological analysis and molecular techniques: Rep-PCR, species and genus specific amplifications and the sequence analysis of 16S rDNA for strain typing and taxonomic identification. The strains belonged to Lactobacillus plantarum, Lactobacillus paracasei, Lactococcus lactis, Lactococcus garviae, Enterococcus faecalis, Enterococcus faecium, Leuconostoc mesenteroides, Leuconostoc pseudomesenteroides, Streptococcus salivarius, Streptococcus millieri, Streptococcus macedonicus and Pediococcus pentosaceus. A wide phenotypic and genomic heterogeneity was observed within the different species (Lactobacillus plantarum, Lactobacillus paracasei and Leuconostoc mesenteroides) according to the origin and the time of ripening. The natural microflora was different from strain collection and each method must be combined to identify and characterize natural microflora. This study revealed the low selectivity of selective media used for the isolation of different groups of lactic acid bacteria except the Facultatively Heterofermentative lactobacilli medium selecting mesophile lactobacilli and SB medium selective for Enterococcus. The study reveals, for the first time, the microbial lactic acid bacteria community of Salers cheese and its diversity. A better knowledge of microbial flora will be useful to improve understanding of sensory quality of cheeses.     

传统发酵泡菜中乳酸菌种群组成及优良菌株产酸耐酸特性分析

采用传统分离纯化方法从中国北方4 个不同地区的20 份传统自然发酵泡菜样品中,分离得到435 株疑似乳酸菌,通过16S rDNA序列分析对株菌进行种属鉴定,结果显示分离到的所有菌株均为乳酸菌,其中乳杆菌属6 个种共394 株,分别为莫氏乳杆菌（Lactobacillus modestisalitolerans）、清酒乳杆菌（L. sakei）、棒状乳杆菌（L. coryniformis）、植物乳杆菌（L. plantarum）、短乳杆菌（L. brevis）和徳氏保加利亚乳杆菌（L. delbrueckii subsp. bulgaricus）,肠球菌属共38 株以及2 株肠膜明串珠菌（Leuconostoc mesenteroides）和1 株暹罗片球菌（Pediococcus siamensis）。各地区泡菜样品的微生物菌群组成有差异,其中辽宁和河南的泡菜样品中微生物种群最为丰富,共分离到6 个种,吉林的泡菜样品中产酸菌数量最多。进一步通过乳酸菌24 h产酸曲线测定和耐受模拟人工胃液（pH 2.0）实验,从产酸能力较强菌株中分离到9 株菌在pH 2.0条件下处理3 h存活率在70%以上。研究结果为传统泡菜品质改良及优质菌种资源开发提供理论依据与技术支持。     

Phenotypic and genotypic identification of lactic acid bacteria isolated from ethnic fermented bamboo tender shoots of North East India

Mesu, soidon, soibum and soijim are ethnic fermented bamboo tender shoot products prepared by the people in North East India. Microbiological analysis of mesu, soidon, soibum and soijim showed the population dominated by lactic acid bacteria (LAB) ranging up to 10(8) cfu g(-1). The phenotypic characterisation of predominant LAB isolated from the fermented bamboo shoot products was based on general morphology, physiological tests, API and Biolog systems. The genotypic characterisation of LAB was based on RAPD-PCR, rep PCR, species-specific PCR techniques, 16S rRNA gene sequencing and DNA-DNA hybridisation. Predominant functional LAB strains associated with the fermented bamboo shoot products were identified as Lactobacillus brevis, Lb. plantarum, Lb. curvatus, Pediococcus pentosaceus, Leuconostoc mesenteroides subsp. mesenteroides, Leuc. fallax, Leuc. lactis, Leuc. citreum and Enterococcus durans.     

Characterization and selection of autochthonous lactic acid bacteria isolated from traditional Iberian dry-fermented salchichón and chorizo sausages

ABSTRACT:  A total of 192 lactic acid bacteria were isolated from 2 types of naturally fermented dry sausages at 3 different stages of the ripening process in order to select the most suitable strains as starter cultures in dry-cured sausage manufacture according to their technological characteristics such as glucose fermentation, lactic and acetic acid production, and proteolytic, lipolytic, and antimicrobial activities. Identification of the isolates revealed that 31.2% were Pediococcus pentosaceus , 26.9% Lactococcus lactis , 18.6% Pediococcus acidilactici , 17% Lactobacillus brevis , and sporadic isolates of Leuconostoc mesenteroides , Lactobacillus plantarum , and Lactobacillus curvatus . Most of the strains did not produce gas from glucose and showed the capacity to produce lactic acid rapidly. Some 25% of the strains were able to degrade tributyrin (esterase activity), but none showed lipolytic activity against olive oil and pork fat. Only 3 strains of P. acidilactici showed weak proteolytic activity against myofibrillar or sarcoplasmic proteins. Also, the same strains showed antimicrobial activity against Listeria monocytogenes . Nine strains with the best properties were preselected and tested for biogenic amine production. The results showed that two of the strains, identified as P. acidilactici by polymerase chain reaction, had the potential to be further tested as starter cultures in pilot processing of Iberian sausages.     

几种发酵蔬菜中乳酸菌的分离与筛选

从泡白菜、泡萝卜和泡辣椒中分离出11个乳酸菌株,对各菌株进行了初步鉴定和筛选。结果表明:不同泡菜中的乳酸菌株有明显差异,分离的菌株多以杆状和球状存在,其中泡萝卜中以短乳杆菌为主,泡辣椒中以短乳杆菌和片球菌为主,泡白菜中以短乳杆菌和链球菌为主;供试样品中还含有环丝菌属,丹毒丝菌属,肠球菌属等三个菌属的乳酸菌,乳杆菌属在三种泡菜中存在最广泛。三种泡菜中均含有产亚硝酸盐菌株,其中泡辣椒中的肠球乳酸菌产较多亚硝酸盐,不能作为纯种发酵菌种:各菌种在纯种发酵时所表现出来的适应能力,产酸能力和风味也各不相同。最后采用泡萝卜发酵试验筛选出4个菌株,泡制的萝卜口感和风味好,盐度低,产酸速度快,发酵7d即可基本成熟,pH值可降到4．0以下,保质期长、抑制杂菌能力强。     

乳酸菌对红曲黄酒酿造过程酵母菌生长及风味物质形成的影响

比较了巴氏葡萄球菌、肠膜明串珠菌、戊糖片球菌、乳酸乳球菌、植物乳杆菌和干酪乳杆菌6种乳酸菌对红曲黄酒酿造体系中酵母菌生长及风味物质形成的影响。结果表明:除干酪乳杆菌外,其它乳酸菌均能促进酵母菌的生长;添加乳酸菌虽然对酿造终产物中还原糖与乙醇含量的影响并不显著,但都能显著提高其有机酸含量。利用顶空固相微萃取-气相色谱-质谱联用技术共鉴定出34种挥发性成分,并对发酵终产物进行感官评定,结果发现正丁酸、苯乙醛、2-苯乙醇、乙酸异戊酯、正丙醇和1-壬醇与感官总分呈正相关,乙酸丁酯、辛酸、乳酸乙酯、癸酸乙酯、辛酸乙酯、正丁醇和5-甲基糖醛与感官总分呈负相关。研究结果表明:在酿造体系中添加植物乳杆菌或干酪乳杆菌均会对红曲黄酒品质产生不利影响,而戊糖片球菌对红曲黄酒品质有一定提升,是潜在可应用于酿造红曲黄酒中的优良乳酸菌菌株。     

降亚硝酸盐乳酸菌的鉴定及生长特性的研究

从传统发酵食品中分离乳酸菌,筛选鉴定降解亚硝酸盐能力较强的菌株,并研究其在白菜汁培养基中的生长及产酸情况,为制作泡菜发酵剂储备优良菌株。结果分离了144株乳酸菌,并获得5株亚硝酸盐降解率在99%以上的菌株,经鉴定菌株Mao21.1和Mao6.2为戊糖乳杆菌,Wang3.1和Mao20.1为植物乳杆菌,Lin2.4为戊糖片球菌。5株菌在白菜汁培养基中生长4h后,各菌株培养液的pH均快速下降;培养20h后,除菌株Mao21.1外,其他菌株培养液pH均降到3.5以下;对数生长末期菌株Mao6.2和Lin2.4活菌数达到108cfu/mL,该两株菌可作为制作泡菜发酵剂的储备菌株。     

Phenotypic identification and technological properties of lactic acid bacteria isolated from traditionally processed fish products of the Eastern Himalayas

Sukako maacha, gnuchi, sidra and sukuti are traditional smoked and sun-dried fish products of the Eastern Himalayan regions of Nepal and India. A total of 40 samples of sukako maacha (14), gnuchi (6), sidra (10) and sukuti (10) were collected and were analysed for microbial load. Population of lactic acid bacteria (LAB) as well as aerobic mesophilic counts ranged from 4.7-8.3 to 5.1-8.5 log cfu g(-1), respectively. A total of 189 strains of LAB were isolated from sukako maacha, gnuchi, sidra and sukuti samples, out of which 171 strains were cocci and 15 strains, were heterofermentative lactobacilli. LAB were identified on the basis of phenotypic characters including API system as Lactococcus lactis subsp. cremoris, Lactococcus lactis subsp. lactis, Lactococcus plantarum, Leuconostoc mesenteroides, Enterococcus faecium, Enterococcus faecalis, Pediococcus pentosaceus and Weissella confusa. LAB strains produced a wide spectrum of enzymes. Some strains of LAB showed antagonistic properties against pathogenic strains. None of the strains produced biogenic amines in the method applied. This paper is the first report on the microbial composition, mostly lactic acid bacteria, of traditionally processed fish products of Eastern Himalayas.     

南宁地区米酒曲源乳酸菌在糯米汁中氨基酸和有机酸代谢特征研究

该研究采用纯培养技术对广西省南宁地区米酒曲中乳酸菌多样性进行了解析,旨在揭示其分离株在糯米汁中产氨基酸和有机酸的特征。结果表明,11个样品共分离出20株乳酸菌,分别被鉴定为戊糖片球菌（Pediococcus pentosaceus）、融合魏斯氏菌（Weissella confuse）、类肠膜魏斯氏菌（Weissella paramesenteroides）、屎肠球菌（Enterococcus faecium）、台湾乳球菌（Lactococcus taiwanensis）、植物乳杆菌（Lactobacillus plantarum）和戊糖乳杆菌（Lactobacillus pentosus）,其中戊糖片球菌（P. pentosaceus）占分离株的35%,为南宁地区米酒曲中的优势乳酸菌。选取除屎肠球菌（E. faecium）外的16株乳酸菌分离株进行糯米汁纯种发酵,结果发现所有菌株均不产氨基酸,乳酸为糯米汁中主要有机酸。主成分分析（PCA）结果表明,融合魏斯氏菌（W. confuse）HBUAS53367产有机酸的能力较强,可用于后续进一步研究。