无花果高活性内生真菌菌株的筛选

从无花果(Ficusc arice)的根、茎、叶中分离出64株内生真菌,以金黄色葡萄球菌(Staphylococcus aureus)、大肠杆菌(Escherichia coli)、白假丝酵母菌(Saccharomyces albicans)、粘红酵母(Rhodotorula glutinis)和青霉菌(Penicillium sp.)为指示菌种,对这些内生真菌进行抗菌活性实验。结果表明,高活性菌株隶属于链格孢属(Alternaria sp.)、瓶梗青霉属(Paecilomyces sp.)、青霉属(Penicillium sp.)和镰孢霉属(Fusrium sp.)等属。综合分析认为,编号为FL28内生真菌的抑菌作用值得进一步研究。     

基于高通量测序和可培养方法的勐海发酵普洱茶真菌多样性分析

通过高通量测序技术和传统可培养方法跟踪分析了勐海百中堂茶厂普洱茶发酵过程不同阶段的真菌多样性,采用多相鉴定方法准确鉴定了可培养真菌的分类学地位。可培养方法共分离到真菌107株,包括11个属,16个种,优势种为琉球曲霉(Aspergillus luchuensis)、新黑曲霉(Aspergillus neoniger)、烟曲霉(Aspergillus fumigatus)、青霉(Penicillium sp.)、枝孢菌(Cladosporium sp.)、微小根毛霉(Rhizomucor pusillus)、伞枝横梗霉(Lichtheimia corymbifera)、食腺嘌呤芽生葡萄孢酵母(Blastobotrys adeninivorans)、法布里德巴利酵母(Debaryomyces fabryi)、布兰克假丝酵母(Candida blankii)。高通量测序共分析到真菌69个属,189个OTU,优势属包括枝孢菌属(Cladosporium)、芽生葡萄孢酵母属(Blastobotrys)、假丝酵母属(Candida)。结果显示,普洱茶发酵过程中前期真菌多样性较后期高,研究结果为发酵普洱茶微生物安全性评价及功能性分析奠定了基础。     

浓香型白酒酒醅可培养真菌的分离、鉴定及系统发育分析

对四川浓香型白酒酒醅可培养真菌进行分离、鉴定,并做系统发育分析。运用ITS1-5.8S rRNA-ITS2序列可将部分菌株鉴定到种的水平,可培养丝状真菌优势菌为曲霉属(Aspergillus sp.)、红曲霉属(Monascus sp.)、根霉(Rhizopus sp.)。26S rRNA D1/D2序列可将所有分离酵母鉴定到种的水平,可培养酵母优势菌为假丝酵母属(Candida sp.)和毕赤酵母属(Pichia sp.)。     

西沙野生诺尼种子内生真菌的群落多样性

采用种子表面灭菌、菌种分离与纯化、ITS rDNA和26S rDNA D1/D2区序列测定和系统发育分析方法,对西沙野生诺尼种子内生真菌群落多样性进行了初步研究。从诺尼种子中共分离到内生真菌48株,其中酵母菌39株,霉菌9株;39株酵母菌分属于4个属内的5个种,其中榛针孢酵母(Eremothecium coryli)、Pseudozyma aphidis和浅黄隐球酵母(Cryptococcus flavescens)为优势种,分别占总菌株数的31.25%、27.08%和16.67%;9株霉菌分属于4个属内的4个种,其中Phaeoacremonium sp.和赤霉属(Gibberella sp.)是霉菌中相对优势的种,分别占总菌株数的8.33%和6.25%。研究结果表明,西沙野生诺尼种子中存在大量内生真菌,且种类丰富,其中酵母菌占绝对优势,部分优势种具有潜在的药用价值。     

西沙野生诺尼果内生菌的分离与鉴定

采用传统微生物学分离培养方法对我国海南西沙野生诺尼果内生菌进行分离与鉴定研究。计数结果显示,成熟野生诺尼果内生菌菌落总数达1.0×105CFU/g,其中真菌总数为8.0×103CFU/g。进一步在25²8℃下分离得到22株细菌、14株酵母菌和9株霉菌,分别采用16S rDNA、26S rDNA D1/D2区和ITS rDNA序列进行扩增和系统发育分析。结果表明,(1)22株内生细菌分属于α变形菌纲(α-Proteobacteria)、β变形菌纲(β-Proteobacteria)、γ变形菌纲(γ-Proteobacteria)、厚壁菌门(Firmicutes)和放线菌门(Actinobacteria)5个类群,包括亚西亚菌属(Asaia sp.)、黄杆菌属(Flavobacterium sp.)、伯克霍尔德氏菌属(Burkholderia sp.)、泛菌属(Pantoea sp.)、根瘤菌属(Rhizobium sp.)、类芽孢杆菌属(Paenibacillus sp.)、短小杆菌属(Curtobacterium sp.)、藤黄色杆菌属(Luteibacter sp.)8个属的10个已知种;(2)14株酵母分属于担子菌门(Basidiomycota)和子囊菌门(Ascomycota),包括隐球酵母菌属(Cryptococcus sp.)、Pseudozyma sp.、Sympodiomycopsis sp.和假囊酵母属(Eremothecium sp.)4个属的5个种;(3)9株霉菌均属于子囊菌门(Ascomycota),包括枝孢属(Cladosporium sp.)、轮层炭菌属(Daldinia sp.)、赤霉菌属(Gibberella sp.)、Nemania sp.和青霉属(Penicillium sp.)5个属的5个种。     

赊店老酒大曲中可培养真菌的分离和鉴定

该研究采用传统分离培养方法,对赊店老酒大曲中的真菌进行分离纯化并通过形态学观察及分子生物学鉴定确定所获菌株的分类地位。结果表明,老酒大曲样品中共计分离得到45株酵母菌和103株霉菌。共鉴定出6株酵母菌,分别为酿酒酵母（Saccharomyces cerevisiae）、异常威克汉姆酵母（Wickerhamomyces anomalus）、扣囊复膜酵母（Saccharomycopsis fibuligera）、发酵毕赤酵母（Pichia fermentans）、胶红酵母（Rhodotorula mucilaginosa）及光滑假丝酵母（Candida glabrata）;酵母的优势菌属为酿酒酵母（Saccharomyces cerevisiae）（相对含量71%）、光滑假丝酵母属（Candida glabrata）（相对含量11%）。共鉴定出4个霉菌属,分别为根霉属（Rhizopus）、横梗霉属（Lichtheimia）、曲霉属（Aspergillus）和毛霉属（Mucor）;霉菌的优势菌属为根霉属（Rhizopus）（相对含量37%）、横梗霉属（Lichtheimia）（相对含量33%）。     

不同厂家永丰辣酱麦曲中真菌群落结构及其理化性质

该研究采用传统培养法及高通量测序技术探究不同永丰辣酱生产厂家麦曲中的真菌多样性，并通过冗余分析对真菌群落与理化性质之间的相关性进行了研究。结果显示，根霉属(Rhizopus)、石座菌属(Petromyces)、脉孢菌属(Neurospora)为不同厂家麦曲样品中的优势菌属。而通过传统分离方法分离得到了根霉属(Rhizopus sp.)、曲霉属(Aspergillus sp.)、脉孢菌属(Neurospora sp.)、横梗霉属(Lichtheimia sp.)的菌株，与高通量测序的结果相似，表明分离得到的菌株可能为各麦曲样品中的主要功能菌株。相关性分析表明，根霉属(Rhizopus)与总酸含量呈正相关，Meyerozyma和威克汉姆酵母(Wickerhamomyces)与总酸和氨基酸态氮含量正相关。该研究为探究麦曲中的优势功能真菌、揭示永丰辣酱风味物质形成原因以及提高永丰辣酱产品的品质奠定了基础。     

剑南春大曲曲药真菌群落结构的分析

以剑南春大曲曲药为研究对象,采用聚合酶链式反应-变性梯度凝胶电泳(PCR-DGGE)技术研究中温大曲真菌群落结构及其多样性分析。研究结果表明,大曲霉菌优势种群主要分布在透孢犁头霉、总状毛霉、黑曲霉、米根霉等。大曲酵母菌优势种群主要分布在酿酒酵母、东方伊萨酵母、汉逊酵母、假丝酵母和毕赤酵母等。     

汾酒大曲可培养真菌多样性的初步分析

从汾酒大曲中分离出81株真菌,并对这81株菌进行了基于rDNA序列的分子生物学鉴定.结果表明,在汾酒大曲中分布有6个属的霉菌和4个属的酵母菌,其中扣囊腹膜孢酵母是优势酵母菌种,伞枝犁头霉和匍枝根霉是优势霉菌菌种.     

山西老陈醋大曲真菌群落结构及多样性分析

为分析山西老陈醋大曲真菌群落结构及多样性,提取山西老陈醋成熟大曲样品总DNA,应用Illumina MiSeq高通量测序技术结合真菌ITS序列分析大曲真菌群落结构和多样性。结果表明:大曲中的真菌种类丰富,包括:子囊菌门、担子菌门和接合菌门,其中子囊菌门为优势菌门,占大曲总真菌的94.74%,担子菌门和接合菌门仅2.70%和2.51%。山西老陈醋成熟大曲在属水平上共检测到26种真菌,主要真菌为假丝酵母菌属(35.24%)、威克汉姆酵母属(11.11%)、曲霉属(27.57%)、链格孢霉属(9.34%)、酿酒酵母菌属(2.11%)、隐球酵母属(1.13%)、横梗霉属(1.14%)和根霉属(1.04%)。本研究结果反映山西老陈醋大曲真菌群落多样性,对揭示山西老陈醋的发酵机理具有一定的参考价值。     

Identification of fungal contamination and determination of mycotoxigenic molds by micellar electrokinetic capillary chromatography in smoked paprika

The purpose of this work was to analyze the fungal contamination in smoked and unsmoked paprika processed from different cultivars of pepper and to investigate the ability of these and other mycotoxigenic molds to grow and synthesize mycotoxins in smoked paprika. Eighteen mycotoxins were evaluated using micellar electrokinetic capillary chromatography. No relevant differences were found in fungal contamination between smoked and unsmoked paprika. The number of yeasts obtained was low, ranging from 0.4 to 3.29 log CFU g(-1); most of the yeast strains were identified as Cryptococcus spp. followed by Candida spp. All mold counts were <4 log CFU g(-1). Aspergillus, Cladosporium, Penicillium, and Fusarium were the predominant hyphomycete genera. Six mycotoxins were identified in the extracts of several strains isolated from paprika and incubated on malt extract agar. Penicillium expansum followed by Penicillium citrinum and Penicillium raistrickii were the dominant mycotoxigenic fungi isolated. Most of themycotoxin-producing fungi produced detectable amounts of mycotoxins when grown on paprika agar.     

Moulds and yeasts in fruit salads and fruit juices

Thirty-eight fruit salad samples including cantaloupe, citrus fruits, honeydew, pineapple, cut strawberries and mixed fruit salads, and 65 pasteurized fruit juice samples (apple, carrot, grapefruit, grape and orange juices, apple cider, and soy milk) were purchased from local supermarkets in the Washington, DC area and tested for fungal contamination. The majority of fruit salad samples (97%) were contaminated with yeasts at levels ranging from <2.0 to 9.72 log10 of colony forming units per gram (cfu/g). Frequently encountered yeasts were Pichia spp., Candida pulcherrima, C. lambica, C. sake, Rhodotorula spp., and Debaryomyces polymorphus. Low numbers of Penicillium spp. were found in pineapple salads, whereas Cladosporium spp. were present in mixed fruit and cut strawberry salads. Twenty-two per cent of the fruit juice samples tested showed fungal contamination. Yeasts were the predominant contaminants ranging from <1.0 to 6.83 log10 cfu/ml. Yeasts commonly found in fruit juices were C. lambica, C. sake, and Rhodotorula rubra. Geotrichum spp. and low numbers of Penicillium and Fusarium spp. (1.70 and 1.60 log10 cfu/ml, respectively) were present in grapefruit juice.     

Moulds, yeasts and aerobic plate counts in ginseng supplements

Forty six ginseng supplement samples including Siberian ginseng root, Chinese ginseng herb and root, and American ginseng root and extract were purchased from retail in the Washington, DC area and from Penn Herb Co. (Philadelphia, PA) and tested for mould and yeast (MY) contamination and the presence of aerobic mesophilic bacteria (APC). Results indicated that 100% of the Siberian ginseng samples were contaminated with fungi and bacteria. MY counts ranged from 8.0 x 10(2) to 1.4 x 10(3) cfu/g whereas the APCs were between 2.3 x 10(4) and 1.0 x 10(6) cfu/g. Most common fungi encountered in this commodity were Penicillium spp., Eurotium rubrum, E. chevalieri and Rhizopus spp. Seventy-eight percent of the Chinese ginseng herb samples were contaminated with fungi and 89% with bacteria at levels ranging between <100 and 6.0 x 10(4) and <100 and 1.2 x 10(6) cfu/g, respectively. Moulds commonly isolated were Alternaria alternata, Aspergillus niger, Aspergillus spp., Cladosporium spp., E. chevalieri, Penicillium spp. and Rhizopus spp. Fifty six percent of the Chinese ginseng root samples tested contained fungi (A. niger, Rhizopus spp. and yeasts), and 100% contained bacteria. Fungal counts ranged between <100 and 1.4 x 10(3) cfu/g and APCs were between 3.0 x 10(2) and 6.8 x 10(5) cfu/g. Forty-eight percent of the American ginseng root samples contained moulds and 30% showed bacterial contamination. MY counts were between <100 and 4.3 x 10(5) cfu/g whereas APCs were between <100 and 4.5 x 10(4) cfu/g. A. flavus was isolated from 9% and Penicillium spp. were recovered from 39% of the tested samples. This is the first report of A. flavus contamination in ginseng supplements. No moulds or yeasts were found in ginseng extract, but 50% of these samples contained bacteria at levels ranging between <100 and 1.0 x 10(3) cfu/g.     

The mycobiota of coffee beans and its influence on the coffee beverage

The quality of coffee beverage is influenced by several factors, including the species or botanical variety of the beans, agricultural practices, harvesting, drying and storage techniques and also the preparation of the beverage. Apart from these, there is the input of microbial contamination during the processing of the beans. Numerous studies have demonstrated that fungi are important contaminants of coffee beans, especially just after harvesting and drying. However, the relationship between fungal contamination and the sensorial characteristics of the beverage has yet to be described. The aim of this research was to analyze the mycobiota of coffee beans collected from different stages of the coffee production chain and to correlate these data with the sensorial characteristics of the final beverage. Fungal infection of 22 coffee bean samples from the southwest of São Paulo state was analyzed. Samples were collected from the tree (mature cherries), from the ground, from the patio (mature, immature and dried floaters or overripe cherries from the tree) and from storage facilities. In general, coffee samples from this region showed high fungal infection and contamination was higher than 70% in about 45% of the samples. A high diversity of fungi was isolated from all the coffee samples analyzed and the most common were Penicillium brevicompactum, Aspergillus section Nigri, Penicillium sp. nov. (closely related to Penicillium crustosum) and Fusarium sp. Both P. brevicompactum and Penicillium sp. nov. were found at all processing stages, including in the cherries, showing that these fungi are naturally found in the coffee beans from this region. Floater coffee and coffee from the ground showed negative sensorial evaluation with attributes such as moldy, dirty and fermented and presented a high contamination by Aspergillus section Nigri and Aspergillus westerdijikiae.     

Reprint of “The mycobiota of coffee beans and its influence on the coffee beverage”

The quality of coffee beverage is influenced by several factors, including the species or botanical variety of the beans, agricultural practices, harvesting, drying and storage techniques and also the preparation of the beverage. Apart from these, there is the input of microbial contamination during the processing of the beans. Numerous studies have demonstrated that fungi are important contaminants of coffee beans, especially just after harvesting and drying. However, the relationship between fungal contamination and the sensorial characteristics of the beverage has yet to be described. The aim of this research was to analyze the mycobiota of coffee beans collected from different stages of the coffee production chain and to correlate these data with the sensorial characteristics of the final beverage. Fungal infection of 22 coffee bean samples from the southwest of São Paulo state was analyzed. Samples were collected from the tree (mature cherries), from the ground, from the patio (mature, immature and dried floaters or overripe cherries from the tree) and from storage facilities. In general, coffee samples from this region showed high fungal infection and contamination was higher than 70% in about 45% of the samples. A high diversity of fungi was isolated from all the coffee samples analyzed and the most common were Penicillium brevicompactum, Aspergillus section Nigri, Penicillium sp. nov. (closely related to Penicillium crustosum) and Fusarium sp. Both P. brevicompactum and Penicillium sp. nov. were found at all processing stages, including in the cherries, showing that these fungi are naturally found in the coffee beans from this region. Floater coffee and coffee from the ground showed negative sensorial evaluation with attributes such as moldy, dirty and fermented and presented a high contamination by Aspergillus section Nigri and Aspergillus westerdijikiae.     

Mycobiota of cocoa: from farm to chocolate

The present work was carried out to study the mycobiota of cocoa beans from farm to chocolate. Four hundred and ninety-four samples were analyzed at various stages of cocoa processing: (i) primary stage at the farm (fermentation, drying, and storage), (ii) secondary stage at processing (testa, nibs, liquor, butter, cake and powder) and (iii) the final chocolate product (dark, milk, white and powdered) collected from retail outlets. Direct plating or dilution plating on Dichloran 18% Glycerol agar were used for cocoa beans and processed product analyses, respectively. Fungi were isolated and identified using different keys of identification. The largest numbers and diversity of fungi were observed in the samples collected at the farm, especially during drying and storage. The species with the highest occurrence among samples were: Absidia corymbifera, Aspergillus sp. nov., A. flavus, Penicillium paneum and yeasts. A total of 1132 potentially toxigenic fungi were isolated from the following species or species groups: A. flavus, Aspergillus parasiticus, Aspergillus nomius, Aspergillus niger group, Aspergillus carbonarius and Aspergillus ochraceus group. The highest percentage of toxigenic fungi was found at the drying and storage stages. The industrial processing reduced the fungal contamination in all fractions and no fungi were found in the final chocolate products. The knowledge of which fungi are dominant at each processing stage of cocoa provides important data about their ecology. This understanding leads to a reduction in fungal spoilage and mycotoxin production in this product.     

荔枝干微生物菌落分析及其霉菌的分离鉴定

为了研究荔枝干贮藏销售期内普遍存在的微生物超标及霉变问题,对市场零售的散装荔枝干样品进行了微生物数量的测定,并对散装和真空包装的荔枝干样品中的霉菌进行了分离、纯化、鉴定。结果表明:20%样品菌落总数>750cfu/g,80%样品霉菌总数>50cfu/g,抽样合格率为20%;从荔枝干样品中分离得到5株霉菌,通过形态学观察鉴定为黄曲霉、黑曲霉、烟曲霉、红曲霉和黑绿青霉,并确定曲霉属菌株为荔枝干表面霉菌的优势菌群。     

Microbiology of wheat and flour milling in Australia

A survey was undertaken to determine the microbiological status of Australian wheat and the distribution of microorganisms in the flour milling fractions and end products. A total of 650 milling process and end product samples was obtained from nine flour mills located in New South Wales (4), Queensland (2), Victoria (2) and Western Australia (1) during the 1997-1998 and 1998-1999 wheat seasons. Most frequent (modal) counts in wheat and flour were, respectively, as follows: aerobic mesophilic plate count, 10(5) and 10(2) colony forming units/gram (cfu/g); coliforms, 10 and 1 most probable number/gram (MPN/g); Bacillus spp., 10(4) and 10(2) cfu/g; B. cereus, 1 and 0.1 MPN/g; mesophilic aerobic spores, 10 and 1 cfu/g; aerobic thermophiles, both 10 cfu/g; yeasts, 10(3) and 10(2) cfu/g, and moulds, 10(3) and 10(2) cfu/g. Bacillus spp., coliforms, yeasts and moulds were the most frequently detected microorganisms throughout the survey. The most common moulds isolated were Aspergillus, Penicillium, Cladosporium and Eurotium spp. Environmental serovars of Salmonella were isolated from two samples. Escherichia coli and B. cereus were present at very low levels, a majority of positive samples being at the minimum level of detection (3 and 0.3 MPN/g, respectively). As wheat grain layers are separated, surface-adhering contaminants are concentrated in end product bran, wheat germ and pollard, which comprise the outer layers of the grain. Consequently, the inner endosperm fraction contains lower microbial counts, and flour is the cleanest end product of the milling process. Higher microbiological counts midstream in the milling process indicate that equipment contamination may contribute to microbiological contamination; however, the microbiological quality of incoming wheat has a strong influence on the ultimate quality of milling end products.     

不同处理方式的大曲真菌群落差异分析

为探究热风干燥工艺对贮存期大曲中真菌群落的影响,采用实时荧光定量聚合酶链式反应和Illumina?MiSeq高通量测序技术分析和比较不同处理方式的大曲真菌群落的差异。结果表明不同处理方式大曲中的真菌18S?rRNA基因拷贝数在1×1011～4.5×1011?copies/g之间,ZR3拷贝数最大为4.5×1011?copies/g。不同处理大曲的优势真菌类群均为嗜热子囊菌属（Thermoascus）、根毛霉属（Rhizomucor）、曲霉菌属（Aspergillus）、假丝酵母属（Candida）。其中嗜热子囊菌属在大曲真菌群落中具有明显的优势,若要保持其优势,需提供曲库的贮存条件;实验室贮存环境相比于曲库更有利于曲霉菌属类的生长;干燥工艺后的环境更利于假丝酵母属类生长。大曲RG3（热风干燥处理的大曲在实验室条件下贮存2 个月）的多样性指数较高,真菌群落有较大的变化,差异性明显;其中耐盐真菌（Wallemia）、丝衣霉菌属（Byssochlamys）、青霉菌属（Penicillium）、曲霉菌属（Aspergillus）是RG3区别于其他大曲的主要真菌群类;同时主成分分析看出大曲RG3落点相对较远,此类大曲有进一步研究的价值,为大曲热风干燥工业化应用提供指导。     

人工发酵剂对湘西腊肠微生物菌群和理化特性的影响

本文从动态角度探讨自然发酵、戊糖片球菌发酵、木糖葡萄球菌发酵和混合菌发酵腊肠在发酵过程中五种菌相(细菌总数、乳酸菌、葡萄球菌、酵母菌和肠细菌)和理化特性的阶段性变化。微生物数据显示,四组腊肠初始肠细菌数量约5.30 logCFU/g,而发酵结束,添加了戊糖片球菌腊肠组的肠细菌数量约1.00 logCFU/g,没有添加该菌腊肠组的肠细菌数量约3.30 logCFU/g,说明戊糖片球菌能有效抑制肠细菌的生长,保证了产品的安全性和稳定性;发酵初期,腊肠p H值迅速降5.30以下,到发酵中期,腊肠p H开始回升;在发酵过程中,戊糖片球菌腊肠组的TBARS(硫代巴比妥酸)值显著(p0.05)高于其他三组腊肠,而其它理化特性无显著差异。从数据分析可知,腊肠的发酵剂能有效改善其卫生质量,而对腊肠的p H值、AW和亚硝酸盐残留量没有显著影响。