东北泡菜中抑菌微生物的分离筛选及鉴定

实验的目的是分离延边泡菜中具有抑制金黄色葡萄球菌和大肠杆菌的微生物。采用稀释涂布的方法分离泡菜中微生物,挑选110株拟似乳酸菌的菌落,采用管碟法筛选具有抑菌能力的乳酸菌,通过菌落的培养特征、革兰氏染色实验和过氧化氢酶反应实验、生理生化(糖发酵实验)及16S rRNA基因鉴定,结果为62株抑制金黄色葡萄球菌的乳酸菌中11株为植物乳杆菌Lactobacillus plantarum;51株为Lactobacillus acidophilus。91株抑制大肠杆菌的乳酸菌中72株为植物乳杆菌Lactobacillus plantarum;19株为Lactobacillus brevis。表明东北泡菜中乳酸菌具有抑制金黄色葡萄球菌和大肠杆菌的作用。     

醉鱼中菌种的分离筛选与鉴定研究

为优化醉鱼的加工工艺,从传统发酵方法制作的醉鱼中分离纯化获得14株乳酸菌和9株葡萄球菌。通过形态学鉴定、生化鉴定以及糖醇发酵试验,筛选出2株戊糖乳杆菌、2株米酒乳杆菌、1株干酪乳杆菌及2株木糖葡萄球菌。5株乳酸菌和2株葡萄球菌都可作为水产制品的发酵剂。     

盐干带鱼中乳酸菌的分离鉴定及其生物学特性研究

研究了盐干带鱼加工过程中微生物的消长规律,并对产品中乳酸菌进行了分离鉴定和生物学特性研究.研究结果表明,盐干带鱼加工过程中细菌总数、酵母、乳酸菌、葡萄球菌和微球菌均呈现逐步增加趋势,其中乳酸菌为优势菌群.从产品中分离得到G+、H2O2-乳酸菌疑似菌株19株,经生理生化鉴定初步确定为食品乳酸菌(6株)、短乳杆菌(5株)和戊糖乳杆菌(2株),其它未能鉴定种属.食品乳杆菌、戊糖乳杆菌和短乳杆菌均表现出良好的生长性能和耐盐性,未检测到其脂肪酶活性,且仅戊糖乳杆菌表现出弱蛋白酶活性.     

低盐发酵香肠用优良菌株的分离筛选及鉴定

从10 种我国自然发酵制品中分离纯化得到52 株乳酸菌及56 株过氧化氢酶阳性球菌,首先通过菌株耐受性、发酵特性等指标对菌株进行初步筛选,然后利用抑菌特性和风味特性对菌株进行复筛,选择可能改善低盐发酵香肠安全性和风味的优良菌株,最终筛选得到3 株葡萄球菌Z9、L2和R2,以及4 株乳酸菌P6、P12、X和SN1-3。经由形态学特征、生理生化特征及16S rDNA序列分析对筛选得到的菌株进行鉴定,结果表明,葡萄球菌菌株Z9、L2为腐生葡萄球菌,R2为肉葡萄球菌;乳酸菌菌株P6、P12均为植物乳杆菌,X为干酪乳杆菌,SN1-3为戊糖片球菌。最后测定菌株的生长特性及产酸能力,研究菌株间的拮抗特性,最终筛选得到戊糖片球菌SN1-3与肉葡萄球菌R2作为制作发酵香肠的复配菌株。     

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。     

朝鲜族传统大酱中乳酸菌的分离及其抑菌特性分析

为了分析朝鲜族传统酱类中乳酸菌分布及其功能特性,对不同地区家庭制作的朝鲜族大酱进行乳酸菌的筛选和分离纯化,并进行抑菌性能的研究。结果,从26种样品中共分离出86株乳酸菌,其中48株菌株对蜡样芽孢杆菌有抑制作用,47株菌株对鼠伤寒沙门氏菌有抑制作用,55株菌株对大肠杆菌有抑制作用,12株菌株对金黄色葡萄球菌有抑制作用。通过16SrRNA基因序列分析对代表菌株进行鉴定,鉴定出3种乳酸菌种类,分别为戊糖片球菌、乳酸片球菌、植物乳杆菌。     

盐干带鱼中葡萄球菌的分离鉴定及其特性研究

研究了盐干带鱼加工过程中各种微生物类群数量的变化,并对产品中葡萄球菌进行了分离鉴定和生物学特性研究。结果表明,整个加工过程中细菌总数、酵母、乳酸菌、葡萄球菌和微球菌均呈现逐步增加趋势,葡萄球菌是盐干带鱼中重要微生物类群之一。从产品中分离得到葡萄球菌疑似菌株20株,经鉴定初步确定为木糖葡萄球菌(7株)、松鼠葡萄球菌(3株)、马胃葡萄球菌(3株)、腐生葡萄球菌(3株)和耳氏葡萄球菌(2株),其余2株未能鉴定种类,其中木糖葡萄球菌为优势葡萄球菌。与耳氏葡萄球菌相比,木糖葡萄球菌和松鼠葡萄球菌具有良好的生长性能和耐盐性;酶活性实验表明,松鼠葡萄球菌具有弱蛋白酶活性,木糖葡萄球菌具有弱脂肪酶活性。     

鲊肉粉中乳酸菌和葡萄球菌的筛选及鉴定

从传统发酵鲊肉粉中分离、筛选发酵性能优良的乳酸菌和葡萄球菌,为鲊肉粉接种发酵提供理论依据。按照肉制品发酵菌株的筛选标准,利用形态学特征和16S rDNA序列分析鉴定菌株,筛选出2株乳酸菌A1、C7和2株葡萄球菌S6、S7。结果表明:乳酸菌菌株A1、C7均为植物乳杆菌(Lactobacillus plantarum),能快速产酸,具有较好抑菌特性;葡萄球菌菌株S6为沃氏葡萄球菌(Staphylococcus warneri),S7为巴氏葡萄球菌(Staphylococcus pasteuri),能产蛋白酶和脂肪酶,具有良好的耐盐性和耐亚硝酸盐性,对不同抗生素有不同的敏感性。筛选得到的4株菌株具有良好的发酵特性,乳酸菌和葡萄球菌之间无拮抗作用,复配后用可于鲊肉粉接种发酵。     

自然发酵风干肠中葡萄球菌的筛选与鉴定

以自然发酵风干肠为研究对象,分析了风干肠中细菌总数、葡萄球菌和乳酸菌的变化情况,结果表明,发酵初期葡萄球菌受到乳酸菌的抑制,增长缓慢;发酵后期乳酸菌生长进入衰退期,葡萄球菌开始快速繁殖。通过对风干肠中葡萄球菌的分离筛选,共鉴定出5株符合生产要求的葡萄球菌,分别为模仿葡萄球菌(Staphylococcus simulans),木糖葡萄球菌(Staphylococcus xylosus),腐生葡萄球菌(Staphylococcus saprophyticus),表皮葡萄球菌(Staphylococcus epidermidis)和克氏葡萄球菌(Staphylococcus kloosii)。     

湖南腊肉中优势菌种的筛选及初步鉴定

为了研究湖南腊肉生产过程中的微生物生长情况,以传统腊肉为原料,用香肠发酵剂筛选的基本原则进行分离筛选.分离出其中的优势菌,并对其进行生化鉴定,结果表面:湖南传统腊肉中的优势菌为乳酸菌和葡萄球菌,该实验分离出的优势菌为:2株乳酸菌,R1为植物乳杆菌,R2为食品乳杆菌;2株葡萄球菌,A1、A2都为肉葡萄球菌.     

学生宿舍和食堂环境中克罗诺杆菌污染状况及分子分型和耐药特征分析

目的 了解徐州市某学校学生宿舍和食堂环境中克罗诺杆菌污染状况、分子分型及耐药特征,为预警食源性克罗诺杆菌病暴发提供参考.方法 采集徐州市某学校学生宿舍和食堂环境样品156份,分离并鉴定克罗诺杆菌,并利用基于O-抗原的血清分型和多位点序列分型(multilocus sequence typing,MLST)技术对分离株进...     

塔城地区酸马奶中耐乙醇乳酸菌的筛选与鉴定

以新疆塔城地区酸马奶为研究对象,采用传统方法初步筛选出乳酸菌共53株,通过生理生化试验,确定有乳酸杆菌24株,乳酸球菌29株,以不同体积分数乙醇溶液进行胁迫12 h。结果表明,乙醇对菌株的生长有抑制作用,筛选出对乙醇耐受性较强的菌株,其中菌株S7-1、S7-2、SMN3-3、SMN10-1、SNT16可耐受体积分数13%的乙醇胁迫。通过总DNA序列分析,确定菌株SMN3-3为副干酪乳杆菌（Lactobacillus paracasei）,菌株SMN10-1为鼠李糖乳杆菌（Lactobacillus rhamnosus）,菌株S7-1与S7-2为面包乳杆菌（Lactobacillus crustorum）,菌株SNT16为乳酸片球菌（Lactobacillus fermentum）。     

Assessment of potential probiotic properties of Lactobacillus spp., Lactococcus spp., and Pediococcus spp. strains isolated from kefir

In this study, the metabolic activities (in terms of quantities of the produced lactic acid, hydrogen peroxide, and exopolysaccharides) of 8 strains of Lactobacillus spp., Lactococcus spp., and Pediococcus spp., were determined. Lactic acid levels produced by strains were 8.1 to 17.4 mg/L. The L. acidophilus Z1L strain produced the maximum amount (3.18 μg/mL) of hydrogen peroxide. The exopolysaccharides (EPS) production by the strains was ranged between 173 and 378 mg/L. The susceptibility of 7 different antibiotics against these strains was also tested. All strains were found to be sensitive to ampicillin. The tolerance of the strains to low pH, their resistance to bile salts of strains, and their abilities to autoaggregate and coaggregate with Escherichia coli ATCC 11229 were also evaluated. High EPS-producing strains showed significant autoaggregation and coaggregation ability with test bacteria (P < 0.01). A correlation also was determined between EPS production and acid-bile tolerance (P < 0.05). EPS production possibly affects or is involved in acid-bile tolerance and aggregation of Lactobacillus spp., Lactococcus spp., and Pediococcus spp. strains and supports the potential of L. acidophilus Z1L strain as new probiotic.     

高加索酸奶中乳酸菌的分离与鉴定

从自然发酵的5份酸奶样品中,通过平板划线等方法分离筛选乳酸菌。经形态特征,生理生化特性及糖发酵试验等,筛选到12株乳酸菌,分别为:乳杆菌7株,其中:3株德氏乳杆菌保加利亚亚种(Lactobacillus delbrueckii subsp.bulgaricus),3株瑞士乳杆菌(Lactobacillus hel-veticus),1株罗伊氏乳杆菌(Lactobacillus reuteri);乳酸球菌5株,包括3株嗜热链球菌(Streptococcus thermophilus),2株乳酸乳球菌乳脂亚种(Lactococcus lactis subsp.Cremoris)。     

不同品牌酸乳中德氏乳杆菌的分离鉴定及RAPD分析

从不同品牌的10 种酸乳中分离得到10 株德氏乳杆菌(Lactobacillus delbrueckii),经生理生化实验及特异性PCR 鉴定,L.d3、L.d4、L.d5、L.d6、L.d8、L.d10 为德氏乳杆菌保加利亚亚种(Lactobacillus delbrueckii subsp.bulgaricus),L.d1、L.d2、L.d7、L.d9 为德氏乳杆菌乳酸亚种(Lactobacillus delbrueckii subsp. lactis)。利用24 个随机引物对上述10 株德氏乳杆菌进行随机扩增DNA 多态性分析,并使用NTSYSpc-2.10e 软件对扩增图谱数据进行处理,得出10 个菌株之间的遗传相似系数矩阵及聚类分析图。结果表明,10 个菌株相互间的遗传相似系数在0.4167～0.8833 之间,不同菌株间存在一定的亲缘关系及遗传异质性。     

克罗诺杆菌的随机多态性扩增DNA(RAPD)基因分型研究

研究了克罗诺杆菌标准菌株和样品中分离菌株的分子特征,为克罗诺杆菌的种间鉴别和分子溯源提供一种有效手段。采用随机引物扩增多态性DNA分析对38株菌株进行基因分型。筛选出1条随机引物,每一菌株可扩增出1～7条DNA片段,片段在400-3500bp,可将8株标准菌株的种间区分开来。以相似性50%为标准,38株克罗诺杆菌按照其遗传差异可以分为8个基因型类群。所建立的RAPD技术可用于克罗诺杆菌的种间鉴别和分子溯源研究。     

Incidence and characterization of Listeria spp. from foods available in Korea

A total of 410 domestic Korean food samples were analyzed for the presence of Listeria spp. by the conventional U.S. Department of Agriculture protocol, and presumptive strains were identified by morphological, cultural and biochemical tests according to Bergey's manual and confirmed by API-Listeria kit. Among the total 410 food samples, 46 samples (11.2%) were found to be contaminated with Listeria species. Among the 46 strains of Listeria spp. isolates, 8 strains (17.42%) for Listeria monocytogenes, 3 strains (6.5%) for Listeria seeligeri, 33 strains (71.7%) for Listeria innocua, and 2 strains (4.4%) for Listeria welshimeri were identified, respectively. Also, only beef, chicken, pork, frozen foods, and sausage were contaminated with L. monocytogenes, and the other products were free of L. monocytogenes. Of 46 Listeria spp. isolates, L. innocua (71.7%) was the most predominantly isolated in a variety of foods compared to other Listeria spp. An in vitro virulence assay for Listeria spp. using myeloma and hybridoma cells from murine and human sources was performed. The result showed that only L. monocytogenes killed approximately 95 to 100% hybridoma cells after 6 h and the other Listeria species, such as L. innocua, L. seeligeri, and L. welshimeri strains had about 0 to 10% lethal effect on hybridoma cells. Also, an antibiotic susceptibility test showed that Listeria spp. isolates were very susceptible to the antibiotics tested, except for nalidixic acid. Also, serotyping results showed 75% of L. monocytogenes isolates from beef, chicken, and frozen pizza belonged to serotype 1 and 25% from sausage were type 4.     

Identification of Bacillus spp., Escherichia coli, Salmonella spp., Staphylococcus spp. and Vibrio spp. with 16S ribosomal DNA-based oligonucleotide array hybridization

Rapid identification of the genus and species of bacteria in foods and clinical specimens is important. In this report, DNA sequences of bacterial 16S rDNA were used to develop the oligonucleotide array for the identification of bacterial strains of Bacillus spp., Escherichia coli, Salmonella spp., Staphylococcus spp. and Vibrio spp. Most of these bacterial strains may cause food-borne outbreaks or sporadic cases. A rapid (<4 h) detection method that used universal PCR primers to amplify the variable regions of bacterial 16S rDNA, followed by reverse hybridization of the PCR products, which were biotin labeled, to the oligonucleotides arrayed on the chip was developed. Fifteen oligonucleotide probes were selected and spotted on the nylon strip to determine the array hybridization patterns. It was successful in discriminating Bacillus spp., E. coli, Salmonella spp., Staphylococcus spp. and Vibrio spp. with identification, in general, to the genus level, not species level. As 182 randomly selected strains were assayed, the detection rate was found higher than 98%. Except for 3 strains, the remaining 179 strains were correctly identified and no cross reactions were observed. These 179 strains generated five hybridization patterns. Adding more oligonucleotide probes to the array may allow the detection of more bacterial genera and species without significantly increasing the complexity or cost.     

新疆椒麻鸡中腐败细菌的分离与鉴定

为研究新疆椒麻鸡中腐败细菌的种类和特性,采用平板划线法分离腐败菌。利用生理生化实验和16S rDNA序列分析方法,对从椒麻鸡中分离的31 株腐败菌进行鉴定。结果表明：所筛选的31 株菌中,肠杆菌20 株、葡萄球菌3 株、气单胞菌2 株、乳酸菌4 株、溶酪大球菌2 株;新鲜椒麻鸡中的主要腐败菌为溶酪大球菌、葡萄球菌和肠杆菌;低温5 ℃贮藏条件下腐败样品中的主要腐败菌为乳酸菌、葡萄球菌和肠杆菌;常温25 ℃贮藏条件下腐败椒麻鸡中的腐败菌主要为肠杆菌、气单胞菌、葡萄球菌和乳杆菌。