绿衣观音土曲中主导糖化菌的分离与鉴定

观音土曲中的主要微生物有霉菌、酵母及少量的细菌.以本公司保存的绿衣观音土曲为出发菌,采用PDA培养基进行分离、纯化得到了1株糖化能力很强的根霉菌G1.通过微生物形态学、分子生物学鉴定,G1为米根霉(Rhizopus oryzae).     

绿衣观音土曲中微生物种群区系分析及其功能研究

不同地区的绿衣观音土曲和母曲中微生物均表现出较高的一致性，酵母菌和霉菌数量的分布情况因曲而异。微生物类群主要为霉菌、棒曲霉、酵母、放线菌和细菌。绿衣观音土曲中根霉是主要的糖化菌；酵母菌主要代谢生产酒精；细菌可增加酒中风味物质，但若含量过大会影响酒风味的协调；棒曲霉在发酵中产风味物质，酯化生成乳酸乙酯。(丹妮)     

高温大曲中的微生物研究

通过对茅台高温大曲制曲发酵过程进行跟踪检测,初步分离出地霉属、汉逊酵母属、假丝酵母属、毕赤酵母属、丝孢酵母属、红酵母属6种酵母;枯草杆菌群、地衣芽孢杆菌、凝结芽孢杆菌、蜡状芽孢杆菌、苏云金芽孢杆菌等41种细菌;曲霉属、毛霉属、根霉属、犁头霉属、红曲霉属、青霉属、拟青霉属等51种霉菌,共98种微生物.研究发现,高温大曲发酵过程中的微生物总数以细菌为主,高达2.118x107cfu/g·曲;霉菌次之,为6.446x106cfu/g·曲;酵母最少,仅有6.6×104cfu/g·曲.种类却以霉菌为最多,高达51种;细菌次之,为41种;酵母最少,仅发现6种.随着发酵过程的进行,微生物呈现出不同的消长规律,前期以细菌为主,中后期霉菌大幅度增多,在前期和后期酵母偶有发现.     

绿衣观音土曲中细菌的研究

通过对湖南和湖北两省8个酒厂提供的7种绿衣观音土曲和3种母曲进行微生物数量的统计，经分析，小曲中细菌数量达108个／g曲。经过鉴定，小曲中优势细菌以葡萄球菌属、微球菌属、酒明串珠菌属和葡萄糖细菌属居多。     

不同温度刺激处理白云边酒大曲细菌研究

研究采用不同温度、不同激活时间激活培养大曲中的微生物,对中温曲和高温曲中的细菌、酵母菌、霉菌和放线菌采用稀释涂平板法进行分离培养。结果表明,不同的温度和热激条件对大曲微生物的培养存在差异;大曲中细菌数量最多,酵母次之,霉菌量少,放线菌基本没有发现;快生型细菌不管是在中温曲还是在高温曲中都普遍存在,数量最多的是中温曲,对白云边酒的风格特征的形成有一定的作用。     

汾酒大曲发酵过程微生物变化的初步分析

基于传统微生物培养方法对汾酒大曲微生物在制曲过程的消长做了初步的统计分析,并利用现代分子生态学的实验方法进行了跟踪尝试.试验表明,酵母菌的数量整体呈先上升后下降趋势；霉菌的数量整体呈先上升后下降趋势；细菌在大曲发酵过程中的数量变化呈先上升后下降,再略有上升,然后逐渐下降的趋势.     

自然制曲的蚕豆曲中优势微生物的分离与初步鉴定

通过各种培养基进行分离培养,对自然制曲蚕豆曲中的细菌总数、芽孢杆菌、酵母菌、霉菌进行计数;对霉菌进行初步鉴定.结果:从自然制曲蚕豆曲中分离出的霉菌,经鉴定为米曲霉和总状毛霉;微生物菌群,以霉菌为主,米曲霉和毛霉数量分别为2.8×107,3.0×106cfu/g;其次为细菌,数量为5.3×104 cfu/g;酵母菌数量为2.6×102 cfu/g;芽孢杆菌:没有检出.     

大曲培养过程中微生态变化规律的研究

研究了特香型白酒大曲培养过程中微生态的变化规律。结果表明,培养前期细菌数量逐渐增大,两周左右达到最大值;酵母数量逐渐减小,后期略有增大;霉菌数量呈先增加后逐渐降低的趋势。     

仰韶超高温大曲发酵过程中微生物变化的初步分析

通过对仰韶超高温大曲在发酵过程中微生物动态变化的初步试验、分析,结果表明,酵母菌,霉菌和细菌的数量均呈先上升后下降又上升的趋势,并且加入5%超高温细菌曲的试样其细菌数量较加入3%的细菌数量明显增多,其顶火温度较普通高温曲高出2℃。     

热处理辣椒酱贮藏过程中残留微生物分析

四川郫县辣椒酱多采用热处理控制微生物生长以延长货架期,但热处理后残留微生物仍会导致辣椒酱腐败。辣椒酱经80℃、30min热处理后室温贮藏120d期间检测其中菌落总数、大肠菌群、霉菌和酵母数,分别采用16S rDNA和ITS序列鉴定分离的细菌和真菌菌株,并运用PCR-DGGE法分析贮藏终点辣椒酱中细菌群落结构。结果表明：热处理后辣椒酱中微生物减少了90%以上,残留微生物主要为芽孢杆菌(Bacillus sp.),在贮藏期内微生物数量则呈先上升后下降的趋势;PCR-DGGE检测发现贮藏终点辣椒酱中主要残留细菌为乳酸菌(Pediococcus sp.和Lactobacillus sp.)和蜡样芽孢杆菌(Bacillus cereus)。因此,热处理可使辣椒酱中部分微生物致死、亚致死或转为“存活但非可培养” (viable but non-culturable,VBNC)状态,但残留的芽孢杆菌(Bacillus sp.)和乳酸菌可能导致辣椒酱的腐败。有效控制芽孢杆菌将是延长辣椒酱货架期的关键因素。     

绿衣观音土曲中各种微生物种群的相互关系

绿衣观音土曲中主要的微生物为棒曲霉、根霉、酵母和细菌。这些微生物之间存在着相互竞争、相互依存关系。当这些微生物达到某种平衡时，就能有很高的出酒率和良好的酒质。(丹妮)     

绿衣观音土曲中霉菌糖化酶活力的研究

从绿衣观音土曲中分离得到一株棒曲霉,一株黑曲霉,六株根霉。分别采用平板透明圈、比色法测定所有菌株糖化酶活力。透明圈实验中棒曲霉的菌落直径最小,而透明圈直径最大。比色法测得棒曲霉糖化酶活力为1283.9U/g干曲。两种方法的结果都表明棒曲霉是所分离菌株中糖化酶活力最高的。     

绿衣观音土曲中棒曲霉的研究

绿衣观音土曲又叫绿衣小曲，小曲表面绿色真菌是棒曲霉。从酒曲中筛选出1株活性最强菌株HD-11。经分析，棒曲霉HD-11有较强的糖化酶活性，其糖化酶活性高于红曲霉和根霉，仅次于黑曲霉，是一株有开发前景的糖化酶产生茵。(陶然)     

Microbiological evaluation of navy bean flour and its blend with retail ground beef

Sterile water suspensions of navy bean flour (NF) were used as a model medium on which the growth of eight microorganisms important for food hygiene and technology was evaluated. Almost all microorganisms grew better on model mediums with 10 and 15% of NF than on the nutrient broth (control). Retail ground beef with and without 5, 10 and 15% addition of NF was wrapped with plastic film and stored at 4°C. Aerobic plate count, psychrophiles, coliforms and yeasts and molds were assessed after 0, 3 and 6 days. Navy bean flour added to ground beef had a significant effect only on aerobic plate count. Growth of psychrophiles, coliforms, yeasts and molds was not affected by addition of NF. Microflora of retail ground beef-NF blends mainly consisted of Lactobacillus spp., while other genera of bacteria were found in smaller numbers. The pH of blends increased in proportion to the level of NF added and was significantly higher in comparison with retail ground beef alone, but decreased during storage due to the large amount of lactic acid bacteria.     

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。     

The occurrence of fungi, yeasts and bacteria in the air of a Spanish winery during vintage

This research studies the presence of microorganisms of enological interest (yeasts, bacteria and molds) and their evolution in the air of a wine cellar. The samples were taken throughout the winemaking campaign (September-December) in a winery of the D.O.Ca. Rioja, Spain. They were collected using an airIDEAL atmosphere sampler from Biomerieux. For the isolation, specific selective media were used for each group of microorganisms. The results obtained indicate that the presence in the winery air of the various different microorganisms studied is directly related to the winemaking processes that are taking place in the winery. Thus, the number of molds present decreases once grapes have ceased to be brought into the winery. The maximum number of yeasts in the air is found when all the vats in the cellar are fermenting, while the lactic bacteria are not detected until the first malolactic fermentation begins. The species of yeasts and molds identified are also related to the winemaking processes. The coincidence of strains of Saccharomyces cerevisiae among those present in the vats during alcoholic fermentation and those isolated from the air, confirms the role of the latter as a transmitter of microorganisms.     

中药材对清香型白酒主要酿造微生物及风味物质的影响

为筛选可提升清香型白酒酿造质量的中药材,探究了20种中药材对发酵微生物酿酒酵母（Saccharomyces cerevisiae）Y1、异常威克汉姆酵母（Wickerhamomyces anomalus）Y29和米根霉（Rhizopus oryzae）G1生长的影响。于绿衣观音土曲中添加中药材,模拟清香型白酒工艺进行固态发酵小试实验,分析中药材的添加对糖化醅中微生物数量及清香型白酒原酒中主要风味物质的影响。结果表明,添加杏仁和甘草等中药材可促进菌株Y1和Y29的生长,添加桂皮、杏仁等中药材可促进菌株G1生长。添加丁香、红景天对菌株Y1、Y29和G1的抑制作用明显,其最适添加量为0.5 g/L。川芎、辣蓼和人参分别使糖化醅中细菌、酵母和霉菌增殖的效果最佳,其微生物增长率分别为143.03%、47.69%和73.47%。气相色谱表明,茴香使清香型白酒乙酸乙酯含量增加32.44%,茯苓使清香型白酒杂醇油含量降低9.23%。     

Acetic Acid, Formic Acid, and Potassium Sorbate as Preservatives for Short Term Storage of Bovine Hides

Total numbers of aerobic microorganisms, Gram negative bacteria, Clostridium perfringens, coagulase positive staphylococci, and yeasts and molds were monitored during storage of segments of bovine hides. The preservatives tested were acetic acid, formic acid, and potassium sorbate. Potassium sorbate at any concentration tested did not control adequately any group of microorganisms monitored. Acetic and formic acids at all concentrations tested, significantly inhibited growth of all groups of microorganisms. At the highest concentration tested (0.67M) not only did the formic acid inhibit growth of microogramisms, but it had a lethal effect on all groups monitored except yeasts and molds. Formic acid was a better preservative than acetic acid. Neither formic nor acetic acid inhibited growth of yeasts and molds to the same extent as the other groups monitored.     

Microflora of minimally processed frozen vegetables sold in Gaborone, Botswana

Two hundred samples of minimally processed, frozen, and prepacked potato chips, peas, corn, and a variety of combined vegetables from supermarkets in Gaborone, Botswana, were examined microbiologically. Determination of aerobic mesophilic plate count, aerobic psychrotrophic plate count, lactic acid bacteria, yeasts and molds, coliforms, Listeria spp., and Staphylococcus aureus were done. Chips had the lowest mean log values for all of the microorganisms enumerated except yeasts and molds. The mean log values for single vegetables ranged from 3.6 to 9.1, 3.4 to 8.9, 2.9 to 5.6, and 2.1 to 6.5 log CFU/ g aerobic mesophilic plate count, aerobic psychrotrophic plate count, lactic acid bacteria, and yeasts and molds, respectively. The microbial profiles of peas and corn were almost similar (P < 0.001). The mean values for combined vegetables were clustered within 4.6 and 5.4 and 4.2 and 5.2 log CFU/g aerobic mesophilic plate count and aerobic psychrotrophic plate count, respectively. All of the vegetables had a coliform population distribution ranging from 0 to < 10(4) most probable number per g. The predominant gram-negative bacteria isolated included members of Enterobacteriaceae and Pseudomonaceae (86.2%). Escherichia coli was not detected in all of the samples. The organisms isolated included those responsible for spoilage in frozen vegetables, namely Pseudomonas, Klebsiella, Corynebacterium, lactic acid bacteria, and Flavobacterium. The predominant lactic acid bacteria were Lactobacillus spp. (55.9%). Other spoilage organisms were yeasts, and Cryptococcus spp. (55.4%) was predominant. Pathogens, namely Listeria monocytogenes, were also isolated at a rate of 2 to 10%, of which 4% was from corn, 2% each from peas and country crop, and 10% from stir-fry. Bacillus cereus was also isolated and accounted for 7.7% of the microorganisms from corn. S. aureus was isolated from all of the vegetables. Enterotoxigenic strains were from corn, peas, mixed vegetables, and stir-fry, and all of them produced enterotoxin A. In addition, the isolates from stir-fry vegetables also produced enterotoxins B and C. The study reveals the presence of pathogens and emerging opportunistic pathogens in the ready-to-use or ready-to-eat vegetables. If E. coli is the only indicator for safety and acceptability, consumers may be exposed to foodborne diseases. Inclusion of other groups as indicator organisms is suggested. Retailers are urged to invest in standby generators to maintain the cold chain.