浓香型白酒窖池微生物分离培养基的选择研究

选择了多种分别针对细菌、酵母菌、霉菌和放线菌等微生物的培养基,对中国浓香型白酒发酵过程中窖池微生物区系的消长情况进行了探讨。实验结果表明,牛肉膏蛋白胨培养基、YPD培养基、淀粉培养基和高氏培养基分别对糟醅和窖泥中细菌、酵母菌、霉菌和放线菌具有较好的分离培养效果。     

白酒曲药微生物分离培养基的选择研究

选择了多种分别针对细菌、霉菌、酵母菌等微生物的培养基和抗生素,对白酒曲药微生物区系进行了研究。实验结果表明,含有50μg/mL制霉菌素的牛肉膏蛋白胨培养基、40μg/mL链霉菌素的YPD培养基、40μg/mL链霉菌素的PDA培养基分别对曲药中细菌、酵母菌和霉菌具有较好的分离培养效果。     

酸乳在加工贮藏过程中微生物菌相演变与卫生标准研究

应用选择性培养基对凝固型酸乳加工过程中细菌菌相演变情况进行分析,同时应用国家标准方法对酸乳加工储藏过程中的微生物卫生指标菌落总数、大肠菌群、霉菌和酵母菌的消长状况进行研究。结果表明假单胞菌、肠杆菌科和乳酸菌是原料乳中的优势菌群,经过杀菌、接种和发酵后,乳酸菌为优势菌群。贮藏一周后霉菌和酵母菌逐渐增加并成为次要优势菌群,三周后细菌菌落总数增加。霉菌、酵母菌和细菌是引起酸乳腐败的主要微生物类群。     

贵州不同地区“生花”糟辣椒中微生物多样性研究

采用Miseq高通量测序技术、传统培养分离法对贵州不同地区的“生花”糟辣椒中微生物进行多样性分析和菌种分离，获得引起糟辣椒“生花”现象的主要微生物。结果表明，4个样品微生物菌相丰度和多样性及传统分离的菌种差异较大，获得细菌和真菌的有效序列分别为97 306条、288 570条。在门水平上，共检测出4个主要细菌门和1个真菌门；在属水平上，共检测出13个主要细菌属及3个主要真菌属。通过基于16S rDNA、ITS测序鉴定并结合菌株发酵特性试验和回接验证试验，获得可引起糟辣椒出现“生花”现象的4株酵母菌分别为库德里阿兹威氏毕赤酵母（Pichia kudriavzevi）、膜璞毕赤酵母（Pichia membranifaciens）、汉逊德巴利酵母（Debaryomyces hansenii）、异常威克汉姆酵母（Wickerhamomyces anomalus）。该研究结果为糟辣椒的保质技术奠定了基础。     

新型白酒糖化发酵剂的制作工艺研究

针对传统浓香型白酒制曲的时间长、工艺复杂、不易控制等问题进行了新型制曲工艺的研究。结果显示，采用窖池糟醅中分离的微生物制成菌悬液，DHA2．4％细菌类培养物，5％酵母菌类培养物，4％霉菌类培养物，37℃培养4d制作糖化发酵剂，测其糖化力、液化力、发酵力均与传统优质曲接近且制作方法简便、快速，为理想的糖化发酵剂制作工艺。     

浓香型白酒主要发酵产物生成与微生物类群的动态变化

为了探索浓香型白酒发酵过程中物质变化趋势,采用气相色谱分析和常规分析的方法,跟踪测定不同层次粮糟在不同发酵时间的主要代谢产物含量。研究表明:糟醅中乙醇、总酸、总酯含量与微量香味成分随着发酵时间的延长呈现一定的规律性;下层糟醅中的产物相应高于上层糟醅中产物;微生物类群数量的相对变化幅度为:酵母菌>细菌>霉菌;上层糟醅的霉菌、酵母菌与细菌的数量分别略高于其下层糟醅的霉菌、酵母菌与细菌数量。本研究初步揭示了浓香型白酒的发酵机理。     

啤酒厌氧菌培养基的选择

啤酒中污染的常见菌有细菌、霉菌、野生酵母菌，但主要存在危害性较大的菌是细菌中的大部分厌氧菌，会使啤酒产生浑浊、变味，变酸等。因此，笔者通过一些实验，有效寻找培养有害厌氧菌的最适培养基。     

窖泥和黄泥微生物分离分析的培养基选择及评价

对黔型浓香型白酒习酒的发酵窖泥及环境土样中微生物区系构成情况进行调查分析,选择多种分别针对细菌、放线菌,酵母菌、丝状真菌等微生物茵群的分离培养基进行了调查探讨.实验结果显示:添加1600 u/mL青霉素钠的培养基可完全抑制原核类微生物菌落的长出.添加0.067%孟加拉红的培养基可抑制部分真菌的扩散生长;选择葡萄糖胰胨琼脂培养基、高氏一号培养基、YEPD培养基或卡尔氏培养基、孟加拉红培养基或淀粉培养基或查氏培养基等,分别用于分离培养细菌、放线茵、酵母菌,丝状真菌等微生物茵群,可获得较好的分离效果和获得更多种群的菌落.在方法学上,采用适合的分离培养基探讨窖泥和黄泥中微生物区系的基本构成是可行的.     

慢咽灵微生物限度检查法验证

建立慢咽灵微生物限度检查法。采用培养基稀释法对慢咽灵微生物限度进行检查,结果表明,慢咽灵可用稀释法检查细菌、霉菌和酵母菌,用常规法检查大肠埃希菌和大肠菌群,用培养基稀释法检查沙门氏菌。     

白云边酒入池发酵过程酒醅中的微生物分析

以白云边酒厂第4轮次入池酒醅正常生产窖池为研究对象,研究酒酷在窖池内不同空间位置的微生物动态变化.结果表明,酒醅在窖池内发酵过程中的微生物主要是酵母菌、细菌、芽孢杆菌及少量霉菌.窖池内上、中、下层不同层面糟的微生物区系在数量上存在一定的差别,总的分布趋势是上层高于中、下层,原酒中微量成分的含量也是上层大于中、下层.     

Survey of yeasts for antagonistic activity against Salmonella Poona in cantaloupe juice and wounds in rinds coinfected with phytopathogenic molds

Application of yeasts as biocontrol agents to prevent mold decay of fruits and vegetables has been described. We examined 10 yeasts for potential antagonistic activity against survival and growth of Salmonella Poona in cantaloupe juice and decay by Cladosporium cladosporioides and Geotrichum candidum in wounds on cantaloupe rind. Cantaloupe juice was inoculated using five schemes: Salmonella Poona only (1.10 log CFU/ml), high (3.93 to 5.21 log CFU/ml) or low populations (1.79 to 3.26 log CFU/ml) of yeasts only, and Salmonella Poona combined with high or low populations of yeasts. High initial populations of Debaryomyces hansenii, Pichia guilliermondii, and Pseudozyma sp. were antagonistic to Salmonella Poona in cantaloupe juice stored at 20 degrees C for 48 h. Wounds in cantaloupe rinds were inoculated with yeast and mold or yeast, mold, and Salmonella Poona, and cantaloupes were stored at 4 degrees C for 14 days or 20 degrees C for 7 days. The pH of rind tissue inoculated with C. cladosporioides and yeasts increased significantly (P < or = 0.05) at 20 degrees C. Wounds that were inoculated with P. guilliermondii, together with C. cladosporioides or G. candidum, did not show mold growth at 4 and 20 degrees C. Populations of Salmonella Poona (6.40, 7.26, and 7.98 log CFU per sample) were lower in wounds coinoculated with G. candidum and three of the test yeasts (D. hansenii, P. guilliermondii, and Cryptococcus albidus, respectively) compared to coinoculation with G. candidum or the other seven yeasts. Candida oleophila and Rhodotorula glutinis showed the most promise in reducing the population of Salmonella Poona in wounds in rinds of cantaloupes coinoculated with G. candidum and stored at 4 degrees C.     

新老制曲车间空气中微生物差异初探

以泸州老窑酒厂新制曲车间和老制曲车间的空气中微生物为研究对象,探讨了新老制曲车间不同环境微生物数量。结果表明,老制曲车间多年富集的微生物数量明显高于新制曲车间,其中曲药库房空气和远离制曲车间50m 左右大环境空气中的霉菌、细菌和酵母菌数量差异均达到显著水平;空发酵房空气中细菌和酵母菌数量差异达到显著水平,而霉菌数量差异不显著;制曲场空气中霉菌、细菌和酵母菌数量差异均不显著。     

黑茶菌添加量对包包曲培菌过程品质的影响

以偏高温包包曲制作工艺为基础,在传统小麦制曲原料中,分别按小麦重量的0%,5%,10%,15%,20%添加含冠突散囊菌的黑茶培养物制曲坯,研究培菌管理过程中主要微生物类群、酶活力和常规理化指标的变化。结果表明：在培菌管理的28 d内,与传统大曲对照组相比,各黑茶菌添加组的微生物类群数量（霉菌、酵母、细菌和冠突散囊菌）、常规理化指标（培菌温度、酒曲水分、酸度和淀粉含量）和酶活力（发酵力、液化酶活力和糖化酶活力）均有不同程度的变化,且各黑茶菌添加组之间也呈不同程度的变化。在传统偏高温包包曲中,采用含冠突散囊菌的黑茶菌培养物进行强化,在培菌管理结束的第28天入库时,15%和20%的黑茶菌添加组的霉菌、细菌和酵母数量均与传统大曲对照组之间差异显著（P<0.05）,说明添加黑茶菌能显著促进大曲中霉菌的生长繁殖、抑制大曲中细菌和酵母菌的生长繁殖;同时,15%和20%的黑茶菌添加组的液化酶活力和糖化酶活力均与传统大曲对照组之间差异显著（P<0.05）,说明添加黑茶菌能显著提高大曲的液化酶活力和糖化酶活力。     

FORMULATION AND TESTING OF CUPRIC SULPHATE MEDIUM FOR WILD YEAST DETECTION

A new differential medium, cupric sulphate medium, used for the detection of wild yeasts has been formulated and tested. This medium suppressed the growth of culture yeasts and supported that of most non-Saccharomyces wild yeasts. It is not suitable for the detection of Saccharomyces wild yeasts. The contaminating wild yeasts in yeast samples and swab samples were easily detected by this medium. Since Lin's medium or modified Lin's medium is suitable for the detection of Saccharomyces wild yeasts, it is suggested that they be used in conjunction with cupric sulphate medium for detecting a more complete spectrum of wild yeasts.     

Insertional mutagenesis in yeasts using T-DNA from Agrobacterium tumefaciens

Insertional mutagenesis is a powerful tool for the isolation of novel mutations. The gene delivery system of the bacterium Agrobacterium tumefaciens, which mediates transfer not only to plants but also to yeasts and fungi, could be exploited to generate collections of yeasts containing insertional mutations if there were no bias towards particular integration sites, as is the case in plants. To test this, we have analysed a small collection of Saccharomyces cerevisiae strains with T-DNA copies integrated in the S. cerevisiae genome. The position of 54 of these T-DNAs was determined. The T-DNA showed no clear preference for certain DNA sequences or genomic regions. We have isolated insertions in the coding regions of the genes YGR125w, YDR250c, YGR141w, YGR045c, YPL017c, YGR040w, YDL052c, YJL148w, YCL033c, YFL061w, YJR033c, YDR175c and YLR309c confirming that these genes are non-essential for S. cerevisiae haploid growth on minimal medium. Given the advantages of T-DNA, we propose its use as an ideal mobile DNA element for insertional mutagenesis in yeasts.     

酶法改变甘草苷糖醛酸基提高其甜度的研究(Ⅰ)——能水解甘草苷糖醛酸基酶的微生物的选择与产酶的研究

以酶法改变甘草苷糖醛酸基提高其甜度为目标,研究了９种新菌株能产水解甘草苷糖醛酸基的β－葡萄糖醛酸苷酶产率。结果：细菌甘Ｅ－１、霉菌甘Ｍ－３和甘Ｍ－６等产β－葡萄糖醛酸苷酶较好,产率分别为５６．７３Ｕ／ｍｌ、４２．５２Ｕ／ｍｌ和３１．２６Ｕ／ｍｌ,产酶最佳培养时间分别为细菌１８ｈ和霉菌４８ｈ。酶解甘草苷的最佳反应条件为：ｐＨ６,反应时间为１２ｈ,反应温度为４０℃。     

Importance of curd-neutralising yeasts on the aromatic potential of Brevibacterium linens during cheese ripening

Three cheese-ripening yeasts Kluyveromyces lactis, Geotrichum candidum and Debaryomyces hansenii were grown in a cheese slurry either individually or in association with the cheese-ripening bacterium Brevibacterium linens. Alcohols, aldehydes and esters were produced by the yeasts, and appeared in the early stages of ripening, whereas volatile sulphur compounds (VSCs) were produced late during the ripening process. The production of VSCs was greatly improved when the yeasts D. hansenii and K. lactis were associated with B. linens. In contrast to G. candidum, these yeasts efficiently neutralised the cheese slurry, which promoted the growth of B. linens. Our results gave evidence of metabolic synergies between the yeasts and B. linens. For instance, generation of S-methyl thioacetate was improved when a yeast that was able to produce esters and thus to accumulate acyl CoA was associated with a bacterium that was able to form large amounts of methanethiol.     

焦糖抗菌作用的研究

本文采用扩散法（管碟法）分别测定了不同浓度的焦糖对部分细菌、霉菌和酵母菌的抗菌效应，结果发现焦糖对所试菌株中的绝大部分细菌和少数酵母有明显抗菌作用，对所试霉菌无任何影响。