酸奶鼓盖的微生物学研究

本文对酸奶中主要微生物进行了研究，发现４种酸奶中都一定程度地污染有细菌、霉菌和酵母。经初步鉴定种类，这些微生物多数在每种酸奶中都存在。说明酸奶环境适合这些微生物生长繁殖。酸奶由于污染微生物而发生鼓盖，引起鼓盖的是酵母菌，细菌、霉菌不能引起酸奶鼓盖。     

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%）。     

PetrifilmTM快速霉菌酵母测试片法与GB 4789.15—2016在酸奶检测中的比较

目的比较Petrifilm~(TM)快速霉菌酵母测试片(RYM)法和GB 4789.15—2016《食品安全国家标准食品微生物学检验霉菌和酵母计数》测定质控样品、标准菌株及野生菌株、酸奶样品和人工污染酸奶样品中霉菌和酵母计数的一致性,研究Petrifilm~(TM)RYM法的特异性。方法选取2份霉菌和酵母计数质控样品、78株霉菌和酵母标准菌株及野生菌株、50份酸奶样品和50份人工污染酸奶样品,利用两种方法进行霉菌和酵母计数的测定,检测结果通过配对资料t检验以及对数值差值绝对值(|dlog|)汇总分析进行统计;同时利用Petrifilm~(TM)RYM法检测15株非霉菌和酵母菌株,考察Petrifilm~(TM)RYM的特异性。结果两种方法对质控样品、标准菌株及野生菌株、酸奶样品和人工污染酸奶样品检测结果的配对t检验均P0.05,差异无统计学意义;|dlog|≤0.50占比均为100.0%,表明两种方法的检测结果一致性较好。Petrifilm~(TM)RYM法检测非霉菌和酵母菌株,结果显示没有菌落出现,表明Petrifilm~(TM)RYM具有良好的特异性。结论 Petrifilm~(TM)RYM法和GB 4789.15—2016对质控样品、标准菌株及野生菌株、酸奶样品和人工污染酸奶样品中霉菌和酵母计数的检测结果一致性较好,且Petrifilm~(TM)RYM具有良好的特异性。     

不同甜酒曲中可培养真菌的多样性分析

用可培养的方法对6种甜酒曲中的真菌进行分离筛选,共分离得到25株酵母菌和13株霉菌,利用26S rDNA序列分析对酵母菌进行鉴定,结果表明,其分属于酿酒酵母（Saccharomyces cerevisiae）、扣囊复膜酵母（Saccharomycopsis fibuligera）、东方伊萨酵母（Issatchenkia orientalis）和克鲁维毕赤酵母（Pichia kluyveri）。利用ITS rDNA序列分析对霉菌菌株进行鉴定,结果表明,13株霉菌分别为米根霉（Rhizopus oryzae）、小孢根霉（Rhizopus microsporus）、小孢根霉华变种（Rhizopus microsporus var. chinesis）、小孢根霉须状变种（Rhizopus microsporus var. rhizopodiformis）、印度毛霉（Mucor indicus）和卷枝毛霉（Mucor circinelloides）。     

民间传统酒曲主要微生物的分离及鉴定

酿造酒的独特风味、质量与酒曲中的微生物密切相关.从选取的民间传统酒曲中主要分离得到酵母茵和根霉菌,还有少量曲霉茵等.通过对其微生物进行茵落特征、茵体形态观察和生理生化特征检测,鉴定出酵母茵有3类,分别为酒香酵母属(Brettanomyces)、假丝酵母属(Candida)、毕赤氏酵母属(Pichia);根霉菌有2类,分别为米根霉(Rhizopus chinensis)和华根霉(Rhizopus oryzae).     

中国东部啤酒厂腐败细菌和野生酵母的检测

本文根据分离的100株啤酒腐败细菌和22株野生酵母,研究了中国东部7家啤酒厂的污染程度评价和质量控制工艺。从每家啤酒厂的五个主要点取样：酿造水和麦汁;发酵液：种酵母;设备、空气和周围环境以及成品啤酒。通过比较分离微生物菌株的16S rDNA,把菌株鉴定到属或种水平,野生酵母鉴定到非酵母属（non-Saccharomyces）和酵母属（Saccharomyces）。在市售脱气lager啤酒中测定微生物生长,表明80％的细菌可引起啤酒污染。中国东部啤酒厂污染情况的研究表明,有害微生物检测对提高这些啤酒厂的卫生质量控制十分重要。     

广东客家黄酒酒曲中微生物的初步鉴定及其产γ-氨基丁酸能力的研究

本文以广东客家黄酒酒曲为对象,对黄酒发酵用红曲、麦曲和酒药中的微生物进行分离,探讨了酒曲中微生物产γ-氨基丁酸(GABA)的能力。研究结果表明,从红曲中分离出2株真菌分离物,其中红曲霉1株和酵母1株;从麦曲中分离出7株真菌分离物,其中毛霉1株,曲霉4株,根霉1株和酵母1株;从酒药中分离出6株真菌分离物,其中根霉1株,曲霉4株和酵母1株。通过生化特性研究及序列分析,鉴定出麦曲的曲霉中有1株为米曲霉,酵母为酿酒酵母。将所分离出的菌株分别进行液态发酵,并采用高效液相色谱检测了发酵液中GABA的含量。研究结果显示,从红曲、麦曲和酒药中分离出来的真菌分离物都具有产GABA的能力,不同真菌分离物产GABA的能力不同。其中,根霉和几株曲霉发酵液中GABA含量较高,特别米曲霉,达到40 mg/L以上,毛霉产GABA含量次之,为34.22 mg/L,而酵母产GABA含量最少,为10 mg/L左右。     

草莓酸奶霉菌酵母污染现状及工艺分析

对北京和南京市售草莓酸奶中霉菌及酵母污染状态进行调查的结果表明，产品中霉菌酵母的污染相当严重，从对生产工艺点的调查结果显示半成品的贮存容器和草莓浆消毒不彻底是导致成品污染的重要因素，因此应加强生产环节的污染控制。并应尽快制定相应的霉菌酵母控制标准。     

啤酒生产中腐败微生物鉴定新技术

啤酒生产过程中的污染微生物主要有野生酵母，细菌，放线菌和霉菌四大类。新的快速检测技术有聚合酶链式反应（PCR）技术，伏安型生物传感器，自动微生物检测系统（AMS），改良MRS培养基和三磷酸腺苷（ATP）法等，较传统方法迅速，准确。     

传统发酵食品-浆水中微生物的分离与初步鉴定

通过对浆水中的微生物进行分离培养及数量测定，查明了浆水中的优势菌为乳酸菌及酵母菌，其次尚有少量放线菌，霉菌为污染菌。从不同样品中分离得到了2株乳酸菌、3株酵母菌，1株放线菌及2株霉菌，通过对其形态、培养特征及生物学特性的研究，初步鉴定2株乳酸菌分属于乳杆菌属（Lactobacillus）和明串珠菌属（Leaconostoc）；3株酵母菌分属于酒香酵母属（Brettanomyces）、隐球酵母属（Cryptococcus）及裂殖酵母属（Schizosaccharomyces）；放线菌属于诺卡氏菌属（Nocardia）；2株霉菌分属于青霉属（Penicillium）和曲霉属（Aspergillus）。     

桃采后病原菌种类及侵染规律研究

本试验以大久保、京玉等北方地区桃主栽品种为试材，研究采后病原菌种类、侵染和发病规律。结果表明：引起桃采后贮藏过程中腐烂的病原菌有8种。不同菌种在不同温度条件下的回接试验表明8种病原真菌的致病性有较大差异，其中灰霉菌（Botrytis cinerea）致病力最强；芽枝霉（Cladosporium sp.）最弱；根霉和黑曲霉多在常温中致病，且病程一般很短：灰霉、交链孢霉在桃低温和高温中均致腐。     

应用PCR-DGGE方法研究甜酒曲中真菌多样性

提取6种甜酒酒曲的总DNA,利用真菌18S rRNA基因片段的通用引物NS1、Fung-GC,采用变性梯度凝胶电泳（PCR-DGGE）方法,进行不同甜酒酒曲中真菌多样性的分析。结果表明,6种甜酒酒曲中共分离出3属真菌和不可培养真菌,湖南韶山的甜酒曲中主要是扣囊复膜酵母属和根霉属的菌株;湖南湘潭甜酒曲中的真菌为酿酒酵母属、扣囊复膜酵母属和根霉属;湖南祁东、福建福州和浙江丽水甜酒曲中的真菌均为酿酒酵母属、扣囊复膜酵母属、根霉属和不可培养真菌;浙江兰溪甜酒曲中的真菌为根霉属和不可培养真菌。在传统的酒曲中的真菌主要是酿酒酵母属和扣囊复膜酵母属,此外不可培养真菌在甜酒酒曲中也起到非常重要的作用。     

Antifungal activity of peppermint and sweet basil essential oils and their major aroma constituents on some plant pathogenic fungi from the vapor phase

The vapors of peppermint oil and two of its major constituents (menthol and menthone), and sweet basil oil and two of its major constituents (linalool and eugenol), were tested against Sclerotinia sclerotiorum (Lib.), Rhizopus stolonifer (Ehrenb. exFr.) Vuill and Mucor sp. (Fisher) in a closed system. These fungi cause deterioration and heavy decay of peach fruit during marketing, shipping and storage. The essential oils, their major individual aroma constituents and blends of the major individual constituents at different ratios inhibited the growth of the fungi in a dose-dependent manner. Menthol was found to be the individual aroma constituent responsible for the antifungal properties of peppermint essential oil, while menthone alone did not show any effect at all doses. In the case of basil oil, linalool alone showed a moderate antifungal activity while eugenol showed no activity at all. Mixing the two components in a ratio similar to their concentrations in the original oil was found to enhance the antifungal properties of basil oil indicating a synergistic effect.     

Mycoflora of two types of Portuguese dry-smoked sausages and inhibitory effect of sodium benzoate, potassium sorbate, and methyl p-hydroxybenzoate on mold growth rate

The mycoflora of chouriqo types Alentejano and Ribatejano, two varieties of Portuguese dry-smoked sausages, have been investigated after a producer-defined shelf life period (120 days at 20 +/- 5 degrees C) in modified atmosphere packaging (55% N2 and 45% CO2). On the basis of morphological and physiological characteristics, the isolates were identified as Penicillium, Aspergillus, Fusarium, Rhizopus, Monilia, Absidia, and Cephalosporium. The species identified were as follows: Penicillium terrestres (43.4%), Penicillium sp. (13.3%), Fusarium sp. (10%), Aspergillus glaucus (10%), Aspergillus versicolor (6.8%), Monilia fruticola (3.3%), Absidia sp. (3.3%), Cephalosporium sp. (3.3%), Rhizopus stolonifer (3.3%), and Fusarium tricinctum (3.3%). Additionally, the effects of three preservatives (potassium sorbate [PS], sodium benzoate [SB], and methyl p-hydroxybenzoate [MHB]) were studied on the growth rate of mold representative isolates. MHB showed a greater inhibitory effect than SB and PS in all fungi isolates, except in A. glaucus [Tm30(A)], in which the inhibitory effect of MHB was similar to PS. At 0.05% (wt/vol), all fungi were inhibited with MHB, except for R. stolonifer [Tm25(A)], which started to decrease the growth rate only at a concentration higher than 0.1%. PS was more effective at inhibiting mold growth than SB, except in Absidia sp. [Tm16(R)], in which both showed a similar inhibitory effect. MHB showed great promise as an application to the surface at 0.1% (wt/vol) to improve the stability and safety of the product through the inhibition of potential spoilage and toxigenic molds.     

鱿鱼丝加工中真菌菌相变化规律及优势真菌的分离鉴定

为减少鱿鱼丝加工过程中真菌污染,提高鱿鱼丝产品的质量,将传统的微生物鉴定技术与5.8S r DNA-ITS序列分析法相结合,并通过系统发育树分析,探索鱿鱼丝加工过程中真菌菌相变化规律及优势菌株。结果表明,在鱿鱼丝加工过程中,不同阶段样品中真菌数量差异显著(p0.05),在加工终点(即烘干包装后)时真菌数量高达2.61 log cfu/g,其中调味和烘干包装阶段是真菌污染的主要环节。加工终点的鱿鱼丝中分离出6种酵母菌和4种霉菌,经测序并通过National Center for Biotechnology Information(NCBI)数据库比对,确定它们分别属于假丝酵母属(Candida sp.)、隐球酵母属(Cryptococcus sp.)、座囊菌属(Dothideomycetes sp.)、胶红酵母属(Rhodotorula sp.)、丝孢酵母属(Trichosporon sp.)、茎点霉属(Phoma sp.)、青霉属(Penicillium sp.)、曲霉属(Aspergillus sp.)、枝孢霉属(Cladosporium sp.)。其中,青霉菌(M-03)和假丝酵母菌(Y-04)为鱿鱼丝加工过程中的优势菌,在加工终点时的数量分别为1.85 log cfu/g和2.15 log cfu/g。     

广东陈香茶渥堆发酵过程中优势微生物群系的演变

对具有地方特色的黑茶品种——广东陈香茶渥堆发酵过程中的优势微生物群系演化进行研究,结果发现其优势种群为黑曲霉(A spergillus niger)、灰绿曲霉(A.gloucus)、产黄青霉(Penicillium chrysogenum)、近平滑假丝酵母(Candida parapsilosis)、根霉(Rhizopus sp.)和木霉(Trichoderma sp.).开潮渥堆开始发酵时,以产黄青霉为主,占47.9％～91.9％.黑曲霉繁殖迅速,在发酵中、后期其占绝对优势(83.1％～97.9％).开潮渥堆时茶堆的含水量对微生物种群演化有显著影响,当其含水量30％～35％时,黑曲霉和酵母的生长繁殖较含水量20％～25％时快.通过水分调控微生物群系,可以达到提高陈香茶品质的目的.     

根霉酯化酶用于酱油增香的优化研究

以豆粕和小麦为主要原料,采用固态低盐原池淋浇发酵法生产基础酱油,对基础酱油使用根霉酯化酶进行增香,通过单因素试验和响应面分析,研究了酯化酶用量、酯化温度和时间对酱油感官和理化质量的影响,结果表明：添加根霉酯化酶能显著提高基础酱油中挥发酯的含量,使酱油滋味醇厚,香气浓郁。优化后的酱油增香工艺条件为：根霉酯化酶1.0%、酯化温度45℃、时间为72h,该条件下酱油总挥发酯的含量为7.512mg/100ml,较基础酱油增加36.3%。     

Antifungal Coatings on Fresh Strawberries (Fragaria × ananassa) to Control Mold Growth During Cold Storage

ABSTRACT: Chitosan (2%) -based or hydroxypropyl methylcellulose (HPMC) (1%) -based coatings were applied on fresh strawberries to evaluate their antifungal efficacies against Cladosporium sp. and Rhizopus sp. Potassium sorbate (PS) was also incorporated into coating formulas to evaluate any additional inhibitory effects on mold inhibition. Strawberries were inoculated with Cladosporium sp. or Rhizopus sp. at a level of approximately 10³ log colony-forming units (CFU) /g, coated with 2% chitosan, 2% chitosan containing 0.3% PS, or 1% HPMC containing 0.3% PS, and stored at about 5°C and about 50% RH up to 23 d for enumeration of mold, yeast, total aerobes, and coli forms. To assess antifungal activity of the coating materials in vitro, coating solutions were embedded into agar plates and the diameters of radial mold growth were measured after inoculation. In addition, weight loss of coated strawberries and water vapor permeability of the coatings were measured. No significant combined inhibitory effects between chitosan and PS on fungal growth on fresh strawberries were detected. However, significant combined inhibition activity was observed in in vitro testing when PS was formulated into chitosan. Antifungal activity of chitosan against Cladosporium sp. and Rhizopus sp. was not affected by the autoclaving process of coating solutions. Coating treatment also reduced total aerobic count, coliforms, and weight loss of strawberries during storage. Hence, chitosan can be used as a natural antimicrobial coating on fresh strawberries to control the growth of fungi, thus extending shelf-life of the fruits.     

Specific fungi as the causative agents of the sporadic disintegration of sulphited strawberries

Summary. Fresh strawberries were inoculated with specific strawberry rotting fungi. When lesions of 1/4 - 1/2 in. diameter had developed on the fruits, they were added to sulphite-preserved strawberries to constitute 25% of the whole contents. Periodically the pulps were examined and breakdown estimated on a four point scale. of the ten species of fungi used only Rhizopus stolonifer, R. sexualis and Mucor sp. induced breakdown of the fruit to a puree-like consistency during storage. Two fungi failed to produce macerating activity and five failed to grow on the fruit before casual contaminants had outgrown them. Botrytis cinerea , the most common strawberry rotting fungus, did not cause breakdown. It is concluded that Rhizopus sp. and Mucor sp. are mainly responsible for the breakdown of sulphite-preserved strawberries and that the prevention of this trouble necessitates the exclusion of infected fruit. Practical recommendations for achieving this object are suggested. It is stressed that a major outbreak of this form of spoilage is still possible.     

Production of soy yogurt enriched with glyceollins

Soy milk was prepared from regular soybean (M1), soybean germinated for 3 days at 25°C (M2), and soybean germinated under fungal infection (M3). Rhizopus microsporus var. oligosporus ATCC 22959 was used as the elicitor for glyceollin production. Each soy milk was fermented with Streptococcus infantarius 12 and Weissella sp. 4 (1:5, v/v) for 12 h at 37°C. Significant induction of glyceollins was confirmed only in M3 soy milk and glyceollins maintained stably during 12 h fermentation period. The concentration of glyceollins in M3 yogurt was 2,400.4±83 and 2,525.2±158 μg/g dry matter (d.m.) at 0 and 12 h, respectively. The amount of daidzein was significantly higher in M3 yogurt (635.1±21) than that of M1 (417±11) and M2 (545±17 μg/g d.m.) yogurt in 12 h (p<0.05). M2 yogurt had the highest amount of genistein (695.3±17) followed by M3 (634.5±26) and M1 (612.5±14 μg/g d.m.) yogurt. M3 soy yogurt also showed the highest content of total phenolic compounds (5.37 mg/g) and antioxidant activity. The results indicated that functional soy yogurt can be prepared from soybean enriched with glyceollins.