PT95菌株和6株标准青霉菌株的亲缘关系分析

目的 分析PT95菌株和6株标准菌株的亲缘关系.方法 用RAPD技术分析PT95菌株、4株PT95的突变株和6株标准菌株,并应用SPSS软件构建聚类图.结果 PT95菌株均与汤姆青霉系的3种已知标准菌有一定的差异,根据聚类图可清楚地将PT95菌株与其它菌株分开.结论 PT95菌株不同于任一汤姆青霉系的已知菌,可能是一新种.     

2株酸梅汤饮料污染霉菌的分离与鉴定研究

目的:对酸梅汤饮料中的污染霉菌进行分离与鉴定.方法:采用涂布分离法分离污染霉菌,经形态学观察和ITS区rDNA序列分析对菌株进行鉴定.结果:从产生絮状沉淀的酸梅汤饮料中分离到2株霉菌,经鉴定这两株污染菌分别为黄暗青霉(Penicillium citreonigrum)和光孢青霉(Penicillium glabrum).结论:根据两种污染菌的常见生境,酸梅汤饮料中的污染菌可能来自生产果汁的水果原料.     

一株抗白色念珠菌的海洋真菌分离鉴定

从广东湛江海域采集到的海泥中分离真菌并通过抗白色念珠菌活性筛选获得强活性菌株GW08072。通过培养特征、形态特征、显微结构分析及ITS rDNA序列比对等方法对菌株GW08072进行分析鉴定,筛选分离到89株真菌,经复筛重复实验得到抗白色念珠菌活性的菌株6株,经复筛得到的GW08072具有较强的抗白色念珠菌活性,经过遗传稳定性跟踪研究发现该菌抗性能够稳定遗传,经鉴定为草酸青霉(Penicillium oxalicum)。     

李果实贮藏期间4 株病原真菌的分离、鉴定及 碳源代谢指纹图谱分析

从采后贮藏过程中发病的“安哥诺”(Prunus angeleno)和“黑琥珀”(Prunus salicina cv. Black amber) 李果实中分离到4株丝状病原真菌。通过对病原菌株形态学特征观察以及核糖体rDNA ITS序列系统分析,确定菌株059#为串珠状赤霉(Gibberella moniliformis)、菌株067#为链格孢菌(Alternaria alternata)、菌株087#为草酸青霉(Penicillium oxalicum)以及菌株088#为塔宾曲霉(Aspergillus tubingensis)。进一步利用Biolog FF MicroPlate分析病原菌对95种碳源的利用能力,结果表明这4种病原菌的最适碳源皆在77种以上,且共同的最适碳源包括D-果糖、D-葡萄糖、蔗糖、山梨糖醇、苹果酸和柠檬酸等45种。     

人源性嗜酸乳杆菌的分离及分子鉴定

从健康婴儿的新鲜粪便中分离纯化的10株乳杆菌,用嗜酸乳杆菌l6S rDNA的特异性引物和建立的PCR方法对乳杆菌分离株进行分子水平上的鉴定。结果表明,有3株菌和嗜酸乳杆菌参考菌株扩增出大小一致的目的片段,证明此3株菌为嗜酸乳杆菌。测序结果显示,3株分离菌株与标准菌株的同源性达到95%以上,进一步说明了3株菌为嗜酸乳杆菌。     

尖孢镰刀菌胡麻专化型（Fusarium oxysporum f.sp.lini）ISSR标记聚类分析

结合形态学特征和分子生物学方法对我国尖孢镰刀菌胡麻专化型菌株进行鉴定、聚类分析和遗传变异分析。结合传统分类方法和ITS序列分析,确定6省区96株菌株为尖孢镰刀菌。采用ISSR（简单重复序列区间）分子标记技术对这96株菌株进行分析,12条引物共扩增出800个条带,多态率条带数为797条,多态率为99.62%;在相似性系数为0.88处,96株供试菌株被分为5个类群。聚类结果表明,胡麻枯萎病菌种内存在明显的多态性,且ISSR类群与地理来源存在相关性。     

新疆野生羊肚菌物种多样性研究

根据子实体形态特征并结合r DNA ITS(Internal Transcribed Spacer)序列分析技术分析了根据形态特征挑选的、采自新疆伊犁、塔城、石河子、乌鲁木齐、阿勒泰五地区的31株野生羊肚菌子实体。r DNA ITS序列分析表明,采自新疆兵团185团且形态学分类为半开羊肚菌(Morchella semilibera)的2株菌株实为羊肚菌科常见属钟菌属的皱盖钟菌(Verpa bohemica)。以2株皱盖钟菌作为外类群,29株样品与来自Gen Bank的羊肚菌属各物种进行ITS序列聚类,可以分为四大聚类群,其中25株菌株与Morchella sp.Mel-17/19/20/34、Morchella sp.Mel-23/24/31/32、Morchella sp.Mel-13/26聚为第I类群;半开羊肚菌单独聚为第II类群;1株菌株与Morchella frustrata聚为第III类群;3株菌株与Morchella sp.Mes-6、Morchella sp.Mes-7、Morchella sp.Mes-17共同聚为第四类群。结合形态学特征,初步认为,上述五地区羊肚菌属至少由7个物种构成。根据国内最新研究资料,其中2种为中国新纪录种,分别为Morchella sp.Mes-17和Morchella frustrata(中立羊肚菌)。     

酶制剂抗菌活性检测标准菌株的药敏性分析

即将正式颁布的国家标准《食品加工用酶制剂通用卫生标准》首次将酶制剂的抗菌活性列入检验指标,并采用了国际标准检验方法。研究针对国际标准方法中规定的6株酶制剂抗菌活性检验标准菌,选择了9大类40种常用抗生素,采用Kirby-Bauer法进行药敏性测定与分析。结果显示,6株标准菌对不同类的抗生素表现为不同的敏感性,但这一菌株组合对全部40种抗生素均为敏感。因此,此菌株组合具有较为广谱的药物敏感性,能较为全面的检测酶制剂中的抗菌物质;且标准菌株的药敏性图谱可为今后进一步分析酶制剂中抗菌活性物质的种类提供参考。     

五株有机高分子化合物降解菌的生物安全性分析

以分离自环洞庭湖水系的3个淡水湖渔场表层底泥样品中的2株产几丁质酶菌株及3株产胶原蛋白酶菌株为研究对象,对其进行酶活分析及分子生物学鉴定,并通过药敏性、溶血性、氨基酸脱羧酶活性及硝酸还原酶活性实验对其安全性进行评价。结果表明,2株产几丁质酶菌株AL1、BM1分别被鉴定为芽孢杆菌（Bacillus sp.）和假单胞菌（Pseudomonas sp.）;3株产胶原蛋白酶菌株ALJ1、BMJ1及DJ2分别被鉴定为Pseudomonas sp.、Pseudomonas sp.和微小杆菌（Exiguobacterium sp.）。安全性试验结果表明,菌株DJ2、BMJ1分别对6种和4种抗生素高度敏感,其余菌株仅对1种抗生素高度敏感;除菌株AL1外,其余4株菌均无溶血性;除菌株DJ2外,其余4株菌均有氨基酸脱羧酶活性;5株菌均无硝酸还原酶活性。综上,菌株BM1和DJ2是降解有机高分子化合物的较安全菌株,可将其应用于有机高分子化合物的降解。     

2015年分离自中国大陆食品的1 070株沙门菌耐药性分析

目的 了解我国2015年食源性沙门菌的耐药状况及mcr-1基因在硫酸粘菌素(conlistin,CT)耐药菌株中的分布情况。方法 采用微量肉汤稀释法测定1 070株食源性沙门菌对10类16种抗生素的药物敏感性,采用荧光定量聚合酶链式反应(PCR)方法检测196株CT耐药菌株中是否存在mcr-1基因。结果 71.9%(769/1 070)的沙门菌对受试的16种抗生素呈现不同程度的耐药性,其中萘啶酸(NAL)、四环素(TET)、氨苄西林(AMP)、氨苄西林/舒巴坦(SAM)4种抗生素的耐药率较高,均在40%以上,未见碳青霉烯类耐药菌株,47.5%(508/1 070)的沙门菌同时耐受3类或3类以上抗生素,表现为多重耐药,同时耐受抗生素种类最高为9类。共存在141种耐药谱,优势耐药谱型为NAL、AMP-SAM-NAL-CT和TET。196株CT耐药沙门菌检出1株携带mcr-1基因且超广谱β-内酰胺酶(ESBLs)阳性的菌株,该菌株为伦敦血清型,是所有测试菌株中唯一1株九重耐药株。部分省份沙门菌耐药率较高。生禽肉和生畜肉来源沙门菌耐药率较高,分别为80.6%(349/433)和73.5%(283/385)。结论 我国2015年食源性沙门菌整体耐药水平较高,且多重耐药情况严重,生禽畜肉是耐药沙门菌的主要来源,我国食源性沙门菌中存在携带mcr-1基因的严重耐药菌株,应引起关注。     

A CAPS test allowing a rapid distinction of Penicillium expansum among fungal species collected on grape berries, inferred from the sequence and secondary structure of the mitochondrial SSU-rRNA

Penicillium expansum is a fungal species highly damageable for the postharvest conservation of numerous fruits. In vineyards, this fungus is sometimes isolated from grape berries where its presence may lead to the production of geosmin, a powerful earthy odorant, which can impair grapes and wines aromas. However, the discrimination of P. expansum from related fungi is difficult because it is based on ambiguous phenotypic characters and/or expensive and time-consuming molecular tests. In this context, the complete sequences and secondary structures of Penicillium expansum and Penicillium thomii mitochondrial SSU-rRNAs were achieved and compared with those of two other phylogenetically related Ascomycota: Penicillium chrysogenum and Emericella nidulans. The comparison has shown a high conservation in size and sequence of the core and of the variable domains (more than 80% of nt identity) of the four SSU-rRNAs, arguing for a close phylogenetic relationship between these four species of the Trichocomaceae family. Large (from 10 to 18 nt) inserted/deleted (indel) sequences were evidenced in the V1, V5 and V6 variable domains. The size variations (10 to 18 nt) of the V1 indel sequence allowed the distinction of the four species; the V5 indel (15 nt) was specifically recovered in E. nidulans; the V6 indel (16 nt), shared by the three Penicillium species, was lacking in E. nidulans. A couple of conserved primers (UI/R2) were defined to generate a PCR product containing the V1 to V5 variable domains. This product contained the two regions of the four SSU-rRNAs showing the highest rates of nt substitutions, namely the V2 variable domain and, surprisingly, a helix (H17) of the core. The H17 sequence was shown to specifically possess in P. expansum a recognition site for the ClaI restriction endonuclease. Hence, this enzyme generates a digestion pattern of the PCR product with two bands (350 bp+500 bp), specific to P. expansum and easily separable by agarose gel electrophoresis. This leads to a CAPS test usable for P. expansum discrimination among grape berries isolated filamentous fungi. The CAPS test was validated by a comparative analysis involving 29 strains belonging to 17 species currently isolated from grape berries in the Bordeaux vineyards.     

成品卷烟霉变微生物的分离纯化与鉴定

从霉变成品卷烟中分离、纯化得到5种菌株,并采用真菌形态学和显微镜检的方法进行鉴定。结果表明,引起卷烟霉变的微生物主要为曲霉菌、青霉菌、链格孢菌和枝孢菌;通过18SrDNA-ITS序列分析及构建系统进化树,鉴定为5个种,分别为聚多曲霉、黄曲霉、极细枝孢霉、指状青霉和链格孢属霉菌;通过致霉性试验得出黄曲霉菌为导致卷烟霉变的主要菌株。     

杨梅贮藏期真菌的分离鉴定及基于ITS序列的聚类分析

目的 分离并鉴定杨梅贮藏期真菌。方法 通过稀释涂布平板分离法以及划线纯化, 从贮藏期杨梅果实中分离、纯化真菌菌种, 并结合传统形态学与ITS (internal transcribed spacer)全序列分析对其进行准确鉴定。结果 最终鉴定出共14株真菌, 其中1株毛霉(Mucor racemosus)、1株白地霉(Geotrichum candidum)、 1株腐皮壳属霉菌(Diaporthe sp.)、1株好食链孢霉(Neurospora sitophila)、3株出芽短梗霉(Aureobasidium pullulans)、4株酵母菌(Pichia kudriavzevii, Pichia terricola, Hanseniaspora opuntiae, Saccharomycopsis crataegensis)以及3株青霉(Penicillium sp., Penicillium expansum, Penicillium herquei)。从进化关系上看有3类显示较近的亲缘关系, 第1类为青霉属, 第2类为出芽短梗霉, 第3类为毕赤酵母。结论 结合传统形态学与ITS全序列分析可对杨梅贮藏期真菌进行更为准确的鉴定。     

Evaluation of several culture media for production of patulin by Penicillium species

The aim of this study was to evaluate different species of Penicillium to identify those which have the potential to produce the greatest amount of the mycotoxin, patulin. Additionally, six different culture media were compared to determine maximum patulin production. Eleven different strains of Penicillium species were selected because they had previously been reported to be producers of patulin. The strains included Penicillium expansum, Penicillium griseofulvum (formerly Penicillium urticae), Penicillium clavigerum, and Penicillium coprobium and a recent Penicillium sp. isolated from an apple. Cultures were grown in duplicate in three different liquid media: potato dextrose, malt extract, and glucose/yeast extract/peptone, both with and without manganese supplementation. Patulin production was compared at 24, 48, 72, and 96 h. Variability in patulin production occurred among the different species, growth media used, and time of incubation. All three of the P. griseofulvum isolates were the highest producers of patulin at 96 h. For most of the strains, potato dextrose broth supplemented with manganese was optimal for maximum production of patulin. Although P. expansum is frequently cited as the most likely source of patulin in apple juice, certain other Penicillium species are capable of producing more patulin than strains of P. expansum. The apple juice industry should be alert to the possibility that Penicillium species other than P. expansum can be responsible for the occurrence of patulin.     

冬季甜瓜腐烂病原菌的分离与鉴定

从冬季贮存甜瓜的腐烂组织中分离病原菌,并对其类型进行检测分析。利用马铃薯葡萄糖琼脂(PDA)培养基和溶菌肉汤(LB)培养基培养,依据微生物形态特性,真菌的26S rRNA 序列和细菌的16S rRNA 序列比对以及系统发育进化分析等分子生物学方法,共分离到22 株菌种,其中真菌13 株：包括青霉2 株、链格孢4 株、白地霉4 株、酵母3 株(梅奇氏酵母2 株、毕赤酵母1 株);细菌9 株：包括沙雷氏菌5 株,丁香菌1 株,克雷伯菌、肠杆菌和芽孢杆菌各1 株。根据26S rRNA D1/D2 区序列比对和系统进化树结果显示,两株酵母菌121 和122 可能是梅奇氏酵母属潜在的新种。青霉和链铬孢是甜瓜腐烂致病菌,白地霉和沙雷氏菌是人体致病菌,表明目前甜瓜贮存方法需要进一步改进和完善。     

氨基酸液生产过程中污染茵的鉴定

从氨基酸液中分离出8株菌,命名为ZH．1—zH一8。7株属十细菌,1株属于霉菌。利用16SrDNA区序列分析并结合彤念学、生邪学特征对细菌菌株进行鉴定。其中,ZH-4为Psychrobacter,ZH-5为Lysinibacilus,ZH-6为Acrococcusviridians,ZH-7为Bacilluspumilus;ZH．3与Planococcus citrcus,ZH-2与Kocuriapalustris,ZH-1与Bacilluspumflus可能为近缘种,有待进一步鉴定。牛弹牛化鉴定结粜与模式菌株相吻合的菌株为ZH-2～ZH-7。18SrDNA区序列分析结合形态学特征鉴定ZH一8为Pcnicillium。ZH-1-ZH-8存GcnBank的登录号依次为JQ819720-JQ819726,JX192597。     

污水中具有絮凝作用丝状菌的分离鉴定及性能研究

目的:为了阐明污泥中丝状菌的种类和特性,利用常规培养技术从山东省临淄区金岭回族镇的污水水渠中分离絮凝菌。方法:利用马铃薯葡萄糖培养基、麦芽汁琼脂培养基和查氏培养基分离出的丝状菌经絮凝率测定和多次富集筛选得到3株絮凝性能稳定且活性良好的菌株,对各菌株进行形态学鉴定,通过单因素实验和正交试验分析各因素对菌株絮凝能力的影响情况。并对其中一株絮凝率高的菌株SP进行了分子生物学鉴定及絮凝率特性分析。结果:经形态学鉴定SQ为青霉属真菌,SR为丛梗孢科某丝状菌,SP经分子生物学鉴定为草酸青霉菌(Penicillium oxalicum)。SP在麦芽汁培养基,pH 6.0,150 r/min,培养温度28 ℃,摇床培养72 h后对5 g/L高岭土悬浮液的絮凝率可达67.7%。结论:分离出的草酸青霉菌等菌株在微生物絮凝剂研究及水体治理方面具有一定的理论和实际意义。     

市售生鲜湿面中腐败菌的分离与鉴定

采用涂布平板法从生鲜湿面中分离腐败菌,通过形态观察及分子生物学技术对分离腐败菌进行菌种鉴定。结果表明,从生鲜湿面中分离得到8株典型菌株,包括3株霉菌和5株细菌。经鉴定,3株霉菌（A1,B1,C1）分别为草酸靑霉（Penicillium oxalicum）、黄曲霉（Aspergillus flavus）、黑曲霉（Aspergillus niger）;5株细菌（S1～S5）分别为3株蜡状芽孢杆菌（Bacillus cereus）、1株肠炎沙门氏菌（Salmonella enterica）、1株副芽孢杆菌（Bacillus paramycoides）。     

Characterization of filamentous fungi isolated from Moroccan olive and olive cake: toxinogenic potential of Aspergillus strains

During the 2003 and 2004 olive oil production campaigns in Morocco, 136 samples from spoiled olive and olive cake were analyzed and 285 strains were isolated in pure culture. Strains included 167 mesophilic strains belonging to ten genera: Penicillium, Aspergillus, Geotrichum, Mucor, Rhizopus, Trichoderma, Alternaria, Acremonium, Humicola, Ulocladium as well as 118 thermophilic strains isolated in 2003 and 2004, mainly belonging to six species: Aspergillus fumigatus, Paecilomyces variotii, Mucor pusillus, Thermomyces lanuginosus, Humicola grisea, and Thermoascus aurantiacus. Penicillium and Aspergillus, respectively, 32.3 and 26.9% of total isolates represented the majority of mesophilic fungi isolated. When considering total strains (including thermotolerant strains) Aspergillus were the predominant strains isolated; follow-up studies on mycotoxins therefore focused primarily on aflatoxins (AFs) and ochratoxin A (OTA) from the latter strains. All isolated Aspergillus flavus strains (9) and Aspergillus niger strains (36) were studied in order to evaluate their capacity to produce AFs and OTA, respectively, when grown on starch-based culture media. Seven of the nine tested A. flavus strains isolated from olive and olive cake produced AF B1 at concentrations between 48 and 95 microg/kg of dry rice weight. As for the A. niger strains, 27 of the 36 strains produced OTA.     

利用谷物进行类胡萝卜素固态发酵

研究了 7种谷物培养基及相关因素对青霉PT95菌株进行类胡萝卜素固态发酵的影响作用。结果表明 ,谷物培养基的组成对PT95菌株在固态发酵条件下的菌核生物量和菌核中的类胡萝卜素含量都有明显的影响 ;接种方式和接种量能明显影响谷物培养基上的菌核生物量 ,但对菌核中的类胡萝卜素含量没有明显的影响 ;在谷物培养基里添加麸皮有利于菌核的形成。在选择最佳接种方式、接种量 ,并在培养基里添加 2 0 %麸皮 (干重 )的固态发酵条件下 ,大米培养基上得到的菌核生物量最高 ,达到 1 5 0 0 g/1 0 0 g(干料 ) ;荞麦培养基上 ,菌核中的类胡萝卜素含量最高 ,达到82 6μg/g(干菌核 ) ;而在谷子培养基上 ,类胡萝卜素产率最高 ,达到 1 1 45 7μg/1 0 0 g(干料 )。