纯种强化发酵细菌型水豆豉细菌菌群动态研究

采用聚合酶链式反应-变性梯度凝胶电泳（PCR-DGGE）技术对利用枯草芽孢杆菌（Bacillus subtilis）BJ3-2强化发酵的细菌型水豆豉前发酵及后发酵过程中的细菌菌群种类及数量进行动态研究。结果表明,前发酵42 h后,细菌种类及数量丰富并趋于稳定,后发酵第5天,细菌种类达到最大。整个发酵期间共鉴定出6个属15个种,包括芽孢杆菌属（Bacillus）、沙雷菌属（Serratia）、产碱菌属（Alcaligenes）、肠球菌属（Enterococcus）、不动杆菌属（Acinetobacter）及变形杆菌属（Proteus）。共检测到6种条件致病菌,分别为粘质沙雷菌（Serratia marcescens）、粪产碱菌（Alcaligenes faecalis）、蜡样芽孢杆菌（Bacillus cereus）、奇异变形杆菌（Proteus mirabilis）、鲍氏不动杆菌（Acinetobacter baumannii）、屎肠球菌（Enterococcus faecium）,其中,奇异变形杆菌首次报道存在于贵州纯种发酵细菌型水豆豉中。     

烧鸡中产芽孢菌的分离鉴定及耐受性比较研究

从烧鸡中筛选出产芽孢菌,探究高温巴氏杀菌后烧鸡腐败的主要原因。利用划线纯化法、革兰氏染色法结合芽孢染色法从烧鸡及其卤汤中筛选出产芽孢菌,然后对菌株进行16S rRNA分析及生理生化鉴定,确定菌株的种属,并对菌株的生长曲线及耐盐、耐酸和耐热性进行研究。结果表明：从烧鸡及其卤汤中共筛选分离出4 株革兰氏阳性芽孢杆菌,分别为海水芽孢杆菌（Bacillus aquimaris）、黄海芽孢杆菌（Bacillus marisflavi）、甲基营养型芽孢杆菌（Bacillus methylotrophicus）和地衣芽孢杆菌（Bacillus licheniformis）,其中,地衣芽孢杆菌的生长繁殖速度最快,至6 h就基本进入生长稳定期;海水芽孢杆菌和黄海芽孢杆菌的耐盐性最强,在NaCl质量浓度达到12 g/100 mL时仍然有部分存活;甲基营养型芽孢杆菌的耐酸性最强,在pH值4.5条件下培养6 h后菌落数能够达到约8（lg（CFU/mL））;在4 株产芽孢菌中,地衣芽孢杆菌的耐热性最强,且不受处理温度和时间的影响。     

高温大曲曲房空气中可培养细菌的分离鉴定及产酶特性

以高温大曲曲房空气中可培养细菌为研究对象,对其进行分离鉴定及产酶特性研究;将得到的优势功能细菌进行高粱汁液态发酵,利用气相色谱—质谱联用法分析其代谢产物。结果表明：从高温大曲曲房空气中共分离出8种菌株,分别为解淀粉芽孢杆菌（Bacillus amyloliquefaciens）、枯草芽孢杆菌（Bacillus subtilis）、蜡样芽孢杆菌（Bacillus cereus）、Pedobacter suwonensis、血红鞘氨醇单孢菌（Sphingomonas sanguinis）、Massilia sp.、Delftia sp.和 Sphingobacterium sp.;经产酶试验筛选得到3株优势功能菌：枯草芽孢杆菌（Bacillus subtilis）、解淀粉芽孢杆菌（Bacillus amyloliquefaciens）和蜡样芽孢杆菌（Bacillus cereus）,均具有纤维素分解能力、淀粉和蛋白水解能力;3株菌的生长曲线表明液体培养4 h达到对数生长期,在高粱汁液态发酵48 h后,优势代谢产物为3-羟基-2-丁酮,且四甲基吡嗪含量也较高,并代谢产生少量高级醇、酚类、酯类等芳香物质。     

2014—2019年岳阳市食源性蜡样芽胞杆菌溶血素hblA与磷脂酶C plc基因特征分析

目的 了解湖南省岳阳市2014－2019年食源性蜡样芽胞杆菌菌株病原学特征,并为蜡样芽胞杆菌引起的食物中毒事件的科学防控提供依据。方法 对2014—2019年分离自湖南省岳阳市城区餐饮门店的26株蜡样芽胞杆菌菌株的致病毒力因子溶血素BL的hblA基因和磷脂酶C的plc基因进行序列扩增和测序,并使用Seqman和MEGA X软件对蜡样芽胞杆菌的hblA和plc基因进行遗传进化分析。结果 从岳阳市分离到的蜡样芽胞杆菌hblA、plc毒力基因的同源性与GenBank中的蜡样芽胞杆菌群相比均大于93.0%。结论 岳阳市分离的蜡样芽胞杆菌的hblA和plc基因与GenBank中的蜡样芽胞杆菌群的同源性高,具有一定的亲缘关系。本研究为进一步了解和科学防控蜡样芽胞杆菌引起的食物中毒事件奠定了研究基础。     

16S与gyrB基因联合建树快速鉴定一株蜡样芽孢杆菌

开发一种可用于保守序列相似度较高的菌群快速鉴定的方法,并用其鉴定一株从土壤采集的芽孢杆菌。从厦门市同安国家农业科技园区施用动物肥的种植区采集土壤,稀释涂布平板,分离纯化菌株后,扩增16S与gyrB基因序列并测序,在Genbank选择序列相似的ATCC菌株进行比对,将16S序列与gyrB序列线性拼接后,利用Paup* 4.0构建进化树,通过生理生化实验对鉴定结果进行验证。在16S序列与gyrB基因序列单独建树均无法鉴定到种的情况下,通过16S与gyrB碱基线性拼接序列联合建树,将土壤中分离得到的芽孢杆菌HX2016002鉴定为蜡样芽孢杆菌,该方法所构建的进化树自展值高,鉴定结果与生理生化实验一致。对Genbank中已知的蜡样芽孢杆菌序列建树分析表明,该方法在蜡样芽孢杆菌中具有普适性。利用16S与gyrB基因拼接序列联合建树,在保守序列相似度高的属内菌种鉴定中具有进一步研究的价值。     

中温酱牛肉中腐败菌的分离鉴定与防腐剂对其抑制作用

将真空包装中温酱牛肉置于25 ℃条件下贮藏,对其中的腐败细菌进行分离和鉴定,并通过管碟法分析肉制品中常用的7种防腐剂对这些菌株的抑菌作用。结果表明,从细菌总数平板上共分离出9株菌落形态不同的微生物菌株,根据形态学、生理生化特征和16S rRNA基因序列分析,发现其由5株枯草芽孢杆菌（Bacillus subtilis）、3株解淀粉芽孢杆菌（Bacillus amyloliquefaciens）和1株蜡样芽孢杆菌（Bacillus cereus）组成。乳酸钠、葡萄糖酸-δ-内酯、双乙酸钠和乳酸链球菌素（Nisin）对9株腐败菌普遍具有较明显的抑菌活性,而山梨酸钾、亚硝酸钠和脱氢乙酸钠抑菌效果相对较差。     

电子束辐照抑制几种常见食源性致病菌生长的研究

为提高电子束辐照对食源性致病菌控制效果,以大肠埃希氏菌、鼠伤寒沙门氏菌、单核细胞增生李斯特氏菌、蜡样芽孢杆菌等4种常见致病菌为对象,通过分析D₁₀值、生长曲线、生物被膜和混菌培养中优势菌,研究了电子束辐照对致病菌生长的影响。结果表明,电子束辐照对4种致病菌具有很强的杀灭作用,D₁₀值范围为0.330~0.648 kGy,多次辐照可导致D₁₀值变小,致病菌对辐照耐受性降低。亚致死剂量电子束辐照可抑制致病菌生长,表现为延迟期延长,且稳定期菌落数量级水平低于对照,在较低温度15 ℃下表现更明显。不同致病菌间进行比较发现,大肠埃希氏菌对辐照最敏感,D₁₀值最低,延迟期滞后程度大于其他致病菌,而蜡样芽孢杆菌的辐照敏感度最低。4种致病菌辐照后共同培养时,蜡样芽孢杆菌在混合菌液中生长受到抑制,由33.49%下降至25.06%,其他3种致病菌百分比都较培养前有所增加。亚致死剂量电子束辐照可影响致病菌生物被膜形成,大肠埃希氏菌、蜡样芽孢杆菌辐照后成膜能力增强,而鼠伤寒沙门氏菌、单核细胞增生李斯特氏菌成膜能力减弱。     

食品中蜡样芽孢杆菌污染的预测模型及风险评估进展

蜡样芽孢杆菌（Bacillus cereus）是一种食品中常见的食源性条件致病菌，其引发的食源性疾病不仅对食用者健康造成严重损伤，也对社会经济造成严重损失。本文综述了近年来国内外对食品中Bacillus cereus污染预测模型的研究及其在风险评估中的应用进展。将影响因素、食品基质、生产链环节、初级模型和次级模型常用拟合模型等进行总结，发现当前预测模型研究最多的是温度、食品成分、水分活度、pH值等因素对Bacillus cereus增殖影响，而温度是主要影响因素；食品主要集中于动物性食品和大米及其制品。Gompertz模型、Logistic模型、Baranyi模型、Weibull等模型常用于拟合生长或失活曲线，建立初级模型；二次多项式模型和平方根模型常用来拟合生长速率或延滞期的变化，建立次级模型；在此基础上，用软件系统建立三级模型。当前的风险评估研究仅涉及到生产环节或从销售到消费环节，尚未见到某类食品从原料环节到消费环节Bacillus cereus预测模型研究的报道。本文展望了食品中Bacillus cereus污染的风险评估研究，以期为今后的研究提供参考。     

餐厨垃圾原位处理菌株的筛选和鉴定

按照产酶能力强、菌株间无拮抗性的原则,从本实验室27株菌中筛选到2株淀粉酶产生菌;苏云金芽孢杆（Bacillus thuringiensis、TKFW r8）和枯草芽孢杆菌（Bacillus subtilis、TKFW 10004）,2株蛋白酶产生菌;蜡样芽孢杆菌（Bacillus cereu. frankland 、TWKF 11014）和纳豆芽孢杆菌（Bacillus natto、TWKF 11002）。将该4株菌与植物乳酸菌(Lactobacillus plantarum、TWKF 12006)和酿酒酵母菌（Saccharomyces cerevisiae Hansen、TKFW 13024）等比例组合,试验结果表明处理后的餐厨垃圾没有恶味,蚊虫较少,具有淡淡的酒香味,能够抑制病原微生物的生长,具有一定的减量效果。为了保证菌株的生物安全性,对未知菌TKFW r8进行观察和鉴定,通过16S rDNA序列分析,确定为苏云金芽孢杆菌。     

面筋中腐败微生物的分离和鉴定的研究

该实验对变质面筋中腐败微生物进行分离,分离出的18株微生物全部为细菌,并对其进行面筋腐败验证试验,所有菌株均能在24 h内引起面筋变质。对面筋中腐败微生物进行分离纯化以及生理生化试验,初步鉴定引起面筋变质的腐败微生物主要为地衣芽孢杆菌（Bacillus licheniformis）,枯草芽孢杆菌（Bacillus subtilis）,巨大芽孢杆菌（Bacillus megaterium）以及蕈状芽孢杆菌（Bacillus mycoides）。     

Starter culture evaluation for the production of ugba from African oil bean seed Pentaclethra macrophylla

Ugba was prepared in the laboratory by the traditional method from the African oil bean seeds Pentaclethra macrophylla. Microorganisms were isolated from the fermenting slices of the beans at 24 h intervals for 5 days and characterised. The results show that only bacteria were isolated from the bean slices. Fungi and yeasts were not isolated. The bacterial isolates were identified as Bacillus subtilis, Bacillus cereus, Pseudomonas chlororaphis, Micrococcus roseus and Staphylococci saprophyticus. The identified bacterial isolates were evaluated for their ability to ferment the cooked oil bean slices into ugba with its desirable quality characteristics of colour, texture, aroma and overall acceptability. Bacillus subtilis was significantly (P<0·05) more active in fermenting the oil bean than the other isolates. Pseudomonas chlororaphis fermented the oil bean actively but caused greening of the slices probably due to the production of the green chloraphin pigment. Staphylococcus saprophyticus, M roseus and B cereus appeared unimportant in the fermentation and may be contaminants. Bacillus subtilis was therefore selected as the single starter culture for ugba production. © 1998 SCI.     

Investigation of the microbial changes during koji‐making process of Douchi by culture‐dependent techniques and PCR‐DGGE

Douchi as a traditional fermentation soyfood with an acquired taste had been appreciated by consumers for thousands of years in China and few Asian countries. Unfortunately, few studies had been conducted on the changes of microbial community during the koji‐making process, and whether the pathogenic microorganisms involving the fermentation process is still unclear. Therefore, the PCR‐denaturing gradient gel electrophoresis (DGGE) targeting the 16S and 18S rRNA genes was applied to characterise the dynamic changes of Bacteria, Bacilli and Fungi during koji‐making process. The results of DGGE showed that eleven species of bacteria, nine species of bacilli and seven species of Fungi had been detected during the koji‐making progress, of which the Bacillus subtilis and Aspergillus oryzae belonged to the dominant microorganisms. Also, eleven strains were isolated from Koji‐making samples and were identified as B. subtilis, Bacillus amyloliquefaciens, A. oryzae, Brachybacterium sp., Aspergillus niger, Staphylococcus saprophyticus, Micrococcus sp., Staphylococcus gallinarum, Absidia corymbifera, Saccharomyces cerevisiae, Malassezia sp.; Our results revealed that pathogenic microorganisms were involved in the koji‐making process, but the probiotic microorganisms occupied the dominant position of community in the koji‐making process.     

AN INVESTIGATION ABOUT ANTIMICROBIAL ACTIVITY OF BLACK CROCUS (STENBERGIA FISCHERIANA)

This study investigated the antimicrobial activity of black crocus (Stenbergia fischeriana), a poisonous herb, on some Gram (+) and Gram (−) microorganisms. Extracts of black crocus were prepared in acetone and tested against Corynebacterium xerosis UC9165, Micrococcus luteus A 2971, Mycobacterium smegmatis CCM 2067, Klebsiella pneumonia FML 5, Bacillus megaterium NRS, Pseudomonas aeruginosa ATCC 27853, Bacillus megaterium DSM 32, Enterococcus faecalis ATCC 15753 and Staphylococcus aureus ATCC 25923 with the disk diffusion method Black crocus had inhibitory activity on Staphylococcus aureus ATCC 25923, Mycobacterium smegmatis CCM 2067, Enterococcus faecalis ATCC 15753 and Klebsiella pneumonia FML 5 but has no inhibitory activity against other bacteria strains.     

Antioxidant and antimicrobial activity of Cynara cardunculus extracts

The whole, fresh involucral bracts of cardoon, Cynara cardunculus L. (Compositae), were extracted with EtOH and an aqueous suspension of the obtained EtOH extract was partitioned successively with CHCl₃, EtOAc and n-BuOH, leaving a residual water extract. All obtained extracts were evaluated for their antioxidant and antimicrobial properties. The antioxidant potential was evaluated using following in vitro methods: FRAP (ferric reducing antioxidant power) assay, and scavenging of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. Antimicrobial activity was estimated using a microdilution technique against food-borne, mycotoxin producers and human pathogenic bacteria and micromycetes. The following bacteria were tested: Salmonella typhimurium, Escherichia coli, Bacillus subtilis, Staphylococcus epidermidis, Staphylococcus aureus, as well as micromycetes: Aspergillus niger, Aspergillus ochraceus, Aspergillus flavus, Penicillium ochrochloron, Penicillium funiculosum, Trichoderma viride, Fusarium tricinctum and Alternaria alternata. Results showed that all extracts possessed concentration-dependent antioxidant activity. In biological assays, C. cardunculus extracts showed antimicrobial activity comparable with standard antibiotics.     

Inactivation Kinetics of Food Poisoning Microorganisms by Carbon Dioxide and High Hydrostatic Pressure

The inactivation kinetics of food poisoning microorganisms using a combined treatment of carbon dioxide (CO₂) with high hydrostatic pressure (HHP) was investigated. Staphylococcus aureus, Fusarium oxysporum, and Fusarium sporotrichioides were totally inactivated by a combined treatment of carbonation and HHP at 500 MP_a. Bacillus subtilis, a spore forming bacteria, were not completely inactivated after the combined treatment. The microorganisms treated by carbonation and HHP were exponentially reduced in a pressure range and the D_p ‐value, the Z^p‐value, and the activation volume were determined. UV absorbing materials leaked from injured cells. Morphological changes of the cells were observed by scanning and transmission electron microscopy.     

Antimicrobial activities of methanol extracts and essential oils of Rosmarinus officinalis, depending on location and seasonal variations

Rosmarinus officinalis is widely found in the lands of Aegean and Mediterranean regions of Turkey. The goal of this work was to test the antimicrobial activity of the essential oils and methanolic extracts of R. officinalis collected from three different regions at four different time intervals of the year against Staphylococcus aureus, Proteus vulgaris, Pseudomonas aeruginosa, Klebsiella pneumonia, Enterococcus feacalis, Escherichia coli, Staphylococcus epidermidis, Bacillus subtilis and Candida albicans. Essential oils were obtained from the aerial parts of the plant by using a Clevenger apparatus, for 4 h. After distillation, the distillates were filtered, air-dried and then extracted by using a Soxhlet apparatus for 9 h to obtain the methanolic extracts. The antimicrobial activities of the methanolic extracts were tested by the disc diffusion technique. The antimicrobial activities of the essential oils obtained from R. officinalis were determined by minimum inhibitory concentration (MIC).The results indicated that the tested bacteria were sensitive to the essential oils and partially to the methanolic extracts. The antimicrobial activities of the essential oils against the tested bacteria differed, depending on location and seasonal variations.     

2015年内蒙古地区31批保健食品中污染菌的分离与鉴定

目的 对保健食品中的污染菌进行分离和鉴定。方法 按照GB 4789《食品安全国家标准 食品微生物学检验》对31批次保健食品进行检验, 采用全自动细菌鉴定系统对污染菌进行鉴定。结果 从31批次的保健食品中分离、鉴定出64株污染菌, 在沙门氏菌、志贺氏菌、金黄色葡萄球菌和溶血性链球菌的检验中未检出目的菌, 但分离得到致病菌和条件致病菌, 分别是阴沟肠杆菌、肺炎克雷伯菌、气味沙雷菌、温和气单胞菌、赫氏埃希菌、阪崎肠杆菌、非脱羧勒菌、泛菌属、缓慢葡萄球菌、浅绿气球菌、哥伦比亚肠球菌、腐生葡萄球菌、产色葡萄球菌、溶血葡萄球菌、铅黄肠球菌、屎肠球菌、以及枯草/解淀粉/萎缩芽孢杆菌、死谷芽孢杆菌、短小芽孢杆菌、凝结芽孢杆菌以及蜡样/苏云金/蕈状芽孢杆菌。结论 各种致病菌及条件致病菌的检出, 对消费者健康存在潜在的风险。通过分析污染菌的来源及危害, 提出提高保健食品卫生质量的建议, 为保健食品的生产、消毒灭菌、卫生学检验及监督管理等方面提供参考。     

Characterization of traditionally fermented Korean soybean paste, eoyukjang, and isolation of its microorganisms

In this study, traditionally fermented Korean soybean paste, eoyukjang, was characterized and its microorganisms were isolated. The contents of amino-type and ammonia-type nitrogens in the pastes we examined were 89.60 to 98.93 mg/% and 0.32 to 0.30 mM, respectively. Antioxidant activity increased during ripening, with antioxidant activities in 1- and 4-year-old pastes measured at 9.80 and 13.84 μmol of Trolox equivalents/g, respectively. Twenty-two and 19 microorganisms were isolated from soybean pastes under aerobic and anaerobic conditions, respectively. After identification, Bacillus amyloliquefaciens, Bacillus subtilis, and Bacillus vallismortis were dominant. In the enzyme activities, protease and lipoxygenase activities were observed from 0.065 to 0.733 unit/mg protein and 0.016 to 0.19 unit/mg protein, respectively. Amylase activity was, however, broad between 43.1 to 571.8 unit/mg protein.     

Microbiological and Toxicological Aspects of Fermentation of Castor Oil Seeds for Ogiri Production

The microorganisms involved in the fermentation of castor oil bean for ogiri production were isolated and characterized. The most predominant microorganism was Bacillus subtilis. Other species were B. licheniformis, B. megaterium and B. firmus. All the Bacillus species were proteolytic and were capable of fermenting castor oil seeds and producing the characteristic ogiri aroma in pure cultures. The optimum pH for growth of the three major isolates was 7-8 while the optimal temperatures were 30^oC for B. subtilis and B. megaterium and 45^oC for B. firmus. Toxicological evaluation of the fermented product by chicken embryo bioassay showed that the initial toxicity of the beans decreased significantly but was not completely eliminated.     

Determination of Relationship between Heating Value and the Thermal Resistance of Microorganisms in Canned Meat

Meat was sterilized with γ-radiation in an aluminium foil bag and then contaminated with a determined quantity of Bacillus subtilis spores. The bag was then placed in the centre of a can filled with meat. After autoclave sterilization, the whole contents of the aluminium foil bags were examined for the quantity of survived bacteria. This procedure enables the determination of thermal resistance of some bacteria on the condition that appears during typical heating processes. Moreover from all the critical areas all surviving microorganisms can be determined.