食品微生物2017
宁波大学942食品微生物学2009--2017,2019年考研初试真题
1、产甲烷细菌和甲烷氧化菌在生态学上的相互关系称
关系；泡菜制作过程中乳酸菌与
腐败菌相互竞争，乳酸菌产生乳酸抑制其它腐败菌生长，其生态学上称
关系。
2、葡萄糖在生物氧化的脱氢阶段中，可通过 4 条代谢途径完成其脱氢反应，它们分别是
途
径、
途径、 ED 途径和
循环。从代谢产物类型来说，色素维生素等属
于
。
3、细胞质中的异染颗粒为
贮藏物，聚 Beta-羟丁酸为
贮藏物。
4、黄酒酿造中制曲的目的有
和
；啤酒酿造中麦芽的作用
酒酿造主发酵温度
； 罐藏食品其微生物检验常用的培养温度有
和
两种。
5、酱油酿造所用典型菌株为
，生理上应具有较强的
酶活性。
6、下列菌名的中文名称：Aspergillus niger
，
Saccharomyces cerevisiae
。
12. 果蔬的腐败常由
等菌引起，是因为
。
13. 梭状芽孢杆菌的分离用
法， 因为
，
14. 配制固体培养基常用的凝固剂为
，其特点为
。
四、问答题（共 8 题，共 60 分）
1．试述烈性噬菌体繁殖的裂解性周期。（7 分）
2．举例说明抗代谢药物的特点及作用机制。（6 分）
3．试比较细胞膜运输营养物质的四种方式及其特点。（6 分）
扩散性运送。
()
4．异型乳酸发酵是乳酸菌通过 HMP 途径且代谢产物不只是乳酸的发酵类型。 ( )
5．分批培养时，细菌经历一个适应期，此期间细胞处于代谢活动的低潮，
细胞数目并不增加。
()
6．Ts 突变株是一类条件致死突变株。
食品微生物基础知识1
特殊结构：鞭毛、荚膜、芽孢和菌毛等。
22
革兰氏阴性和阳性菌
细胞壁区别
G＋（紫色) 胞壁厚度 机械强度 厚，20-80nm 强，较坚韧 G－（红色） 薄，10-15nm 差，较疏松 聚糖骨架，四肽侧链
肽聚糖组 成
肽聚糖层 数 肽聚糖含 量 磷壁酸 外膜层
聚糖骨架，四肽侧 链五肽交联桥 多，可达50层
15
细胞形态
细菌的大小 通常用微米（μm）作测量单位，细菌细 胞的重量约为1×10-9-1×10-10mg，即每g细 菌约含10~100亿个细菌菌体。 细菌的各种形态见下页
16
单球
双球
四联
八叠
葡萄球菌
链球
单杆
双杆
链杆
17
细菌的菌落形态
菌落（colony）：由单个或少量细 胞在固体培养基表面繁殖形成的、肉眼 可见的子细胞群体。 菌落形态包括菌落的大小、形状、 边缘、光泽、质地、颜色、透明程度等。 同一种细菌在一定条件下形成固定的菌 落特征；不同种或同种在不同的培养条 件下，菌落特征是不同的。
46
机器设备卫生控制
CIP清洗终极目的:实现设备商业无菌，首要目标： 实现表面清洁度 。 充填机的外部清洁同样重要： 刷子要求清洁 洗涤剂要求清洁 难洗的小地方要求有专用的小刷子 刷子的形状要合适 全部地方要清洗到位 用后的刷子和桶要干燥保存：刷子可挂起，桶可 倒臵。
26
酵母菌
-酵母菌是一群以单细胞为主的、以出芽为主要繁殖 方式的真菌。 -细胞形态：圆形、卵圆形或柱形，有的可形成象藕 节状的假菌丝。 -菌落形态：菌落表面润湿、粘稠，颜色单调，多呈 乳白色，少数为红色、黑色，易被接种环挑起， 与细菌菌落特征相似，通常比细菌菌落大 -繁殖方式：无性繁殖（分芽殖和裂殖）、有性繁殖 -食品中常见的酵母菌：酒香酵母属、假丝酵母属、 红酵母属、酵母属等等。
(整理)食品微生物习题库
《食品微生物学》习题台州科技职业学院编写者：陈江萍绪论微生物与食品安全1．什么是微生物？什么是微生物学？2．什么是食品微生物学？它与微生物学有何异同？3．你认为微生物学发展中什么是最重要的发现？为什么？4．你认为食品微生物学研究的重点任务包括哪些方面？阐明你的理由。
5．请举例说出微生物在人类生活中的作用。
6．食品微生物学的研究对象是什么？第一章原核微生物第二章真核微生物第三章非细胞生物一、填空：1.细菌的形态十分简单，基本上只有-------、---------、----------三大类。
2.细菌是以----------方式繁殖，并是一种---------性较强的------核微生物。
3.鞭毛是微生物的--------器官。
4.细胞的特殊结构有--------------，----------，----------，---------------。
5.真菌一般包括-----------，-----------------，-------------三种。
6.噬菌体的繁殖一般包括---------，--------，---------，----------，-----------五个阶段。
7.原生质体和球状体有几个共同特点，主要是-------，细胞呈-----状，对-------十分敏感。
8.异染粒功能是---------和----------，并可---------。
9.放线菌是一类呈----------，以----------繁殖的革兰氏-----性细胞。
10.微生物胞内酶作用的最适PH多接近_，而细胞质膜上的酶及胞外膜作用的最适PH则接近--------。
11.平板菌落计数法的原理是在-------或-------中吸有合适的培养基，其中还加有--------。
12.微生物生长曲线包括、、和几个阶段。
13.根据微生物对温度的要求可分为、和三个群体。
14.同步培养技术是指设法使群体中的所有细胞尽可能的都处在-------中，然后分析此群体的各种--------特征，从而了解单个细胞所发生的变化。
食品微生物外文文献2017.1.19
食品微生物外文文献2017.1.19脉冲强光对诺如病毒和沙门及o157的灭活作用Pulsed light (PL) inactivation of two human norovirus (HuNoV) surrogates, murine norovirus (MNV-1) and Tulane virus (TV), and two bacterial pathogens, Escherichia coli O157:H7 and Salmonella, were evaluated. The viruses and bacteria were suspended in phosphate buffered saline (PBS) to final populations of ～6 log PFU/mL and ～6 log CFU/mL, respectively. Both viral and bacterial suspensions were then irradiated by PL for different durations and the reductions of each microorganisms were determined. MNV-1 and TV were significantly (P < 0.05) more resistant to PL treatment than Salmonella and E. coli O157:H7 in PBS suspension. MNV-1, Salmonella and E. coli O157:H7 were also inoculated on strawberries and blueberries and the PL inactivation of each microorganism was determined. Lower inactivation of each microorganism was achieved on berry surfaces than in PBS suspension. This study shows that PL can induce rapid inactivation of MNV-1, TV, Salmonella and E. coli O157:H7 in clear suspension with viruses more resistant to PL treatment than bacteria. The efficacy of PL treatment is substantially influenced by food surface structure.乳酸菌基因组学和代谢组学的研究进展The Lactobacillus genus represents the largest and most diverse genera of all the lactic acid bacteria (LAB), encompassing species with applications in industrial, biotechnological and medical fields. The increasing number of available Lactobacillus genome sequences has allowed understanding of genetic and metabolic potential of this LAB group. Pangenome and coregenome studies are available for numerous species, demonstrating the plasticity of the Lactobacillus genomes and providing the evidence of niche adaptability. Advancements in the application of lactobacilli in the dairy industry lie in exploring the genetic background of their commercially important characteristics, such as flavour development potential or resistance to the phage attack. The integration of available genomic and metabolomic data through the generation of genome scale metabolic models has enabled the development of computational models that predict the behaviour of organisms under specific conditions and present a route to metabolic engineering. Lactobacilli are recognised as potential cell factories, confirmed by the successful production of many compounds. In this review, we discuss the current knowledge of genomics, metabolomics and metabolic engineering of the prevalent Lactobacillus species associated with the production of fermented dairy foods. In-depth understanding of their characteristics opens the possibilities for their future knowledge-based applications.牛肉冷冻状态下的微生物The primary objective of this study was to characterise (microbiology and physical parameters) beef carcasses and primals during chilled storage. A minor aim was to compare observed growth of key spoilage bacteria on carcasses with that predicted by ComBase and the Food Safety Spoilage Predictor (FSSP). Total viable count (TVC), total Enterobacteriacae count (TEC), Pseudomonas spp., lactic acid bacteria (LAB), Brochothrixthermosphacta and Clostridium spp. were monitored on beef carcasses (n = 30) and primals (n = 105) during chilled storage using EC Decision 2001/471/EC and ISOsampling/laboratory procedures. The surface and/or core temperature, pH and water activity (aw) were also recorded. Clostridium (1.89 log10 cfu/cm2) and Pseudomonas spp. (2.12 log10 cfu/cm2) were initially the most prevalent bacteria on carcasses and primals, respectively. The shortest mean generation time (G) was observed on carcasses with Br. thermosphacta (20.3 h) and on primals with LAB (G = 68.8 h) and Clostridium spp. (G = 67 h). Over the course of the experiment the surface temperature dec reased from 37 °Cto 0 °C, pH from 7.07 to 5.65 and aw from 0.97 to 0.93 The observed Pseudomonas spp. and Br. thermosphacta growth was more or less within the range of predictions of Combase. In contrast, the FSSP completely overestimated the growth of LAB. This study contributes to the very limited microbiological data on beef carcasses and primals during chilling.冰箱中牡蛎气调包装的微生物组分变化As filter-feeding bivalves, oysters can accumulate microorganisms into their gills, causing spoilage and potential safety issues. This study aims to investigate the changes in the gill microbiota of oysters packed under air and modified atmospheres (MAs, 50% CO2: 50% N2, 70% CO2: 30% O2, and 50% CO2: 50% O2) during storage at 4 °C. The diversity of bacterial microbiota in oyster gills was profiled through polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis on the 16S rRNA gene V3 region to describe the variation during the entire storage period. The DGGE profile revealed high bacterial diversity in the air- and MA-packaged oyster gills, and the spoilage bacterial microbiota varied in the MA-packaged oyster gills. Results indicated that CO2:O2 (70%:30%) was suitable for oyster MA packaging andthat high bacterial loads in oyster gills need to be considered during storage. In addition, Lactobacillus and Lactococcus species were found to grow dominantly in fresh oyster gills under MA packaging, which supports the potential application of MA packaging for oyster storage.干腌制猪腰猪腿的猪链球菌的生存Dry-cured hams, shoulders and loins of Iberian pigs are highly appreciated in national and international markets. Salting, additive addition and dehydration are the main strategies to produce these ready-to-eat products. Although the dry curing process is known to reduce the load of well-known food borne pathogens, studies evaluating the viability of other microorganisms in contaminated pork have not been performed. In this work, the efficacy of the dry curing process to eliminate three swine pathogens associated with pork carcass condemnation, Streptococcus suis, Streptococcus dysgalactiae and Trueperellapyogenes, was evaluated. Results of this study highlight that the dry curing process is a suitable method to obtain safe ready-to-eat products free of these microorganisms. Although salting of dry-cured shoulders had a moderate bactericidal effect, results of this study suggest that drying and ripening were the most important stages to obtain dry-cured products free of these microorganisms.使用噬菌体提高贝壳类中大肠杆菌的去除率The present study investigated the potential application of the bacteriophage (or phage) phT4A, ECA2 and the phage cocktail phT4A/ECA2 to decrease the concentration of Escherichia coli during the depuration of natural and artificially contaminated cockles. Depuration in static seawater at multiplicity of infection (MOI) of 1 with single phage suspensionsof phT4A and ECA2 was the best condition, as it decreased by ～2.0 log CFU/g the concentration of E. coli in artificially contaminated cockles after a 4 h of treatment. When naturally contaminated cockles were treated in static seawater with single phage suspensions and the phage cocktail, similar decreases in the concentration of E. coli (～0.7 log CFU/g) were achieved. However, when employing the phage cocktail, a longer treatment time was required to obtain comparable results to those achieved when using single phage suspensions. When naturally contaminated cockles were depurated with phage phT4A in a recirculated seawater system (mimicking industrial depuration conditions), a 0.6 log CFU/g reduction of E. coli was achieved after a 2 h of treatment. When the depuration process was performed without phage addition, a 4 h treatment was necessary toobtain a similar decrease. By combining phage therapy and depuration procedures, a reduction in bivalves depuration period can be achieved for, thus decreasing the cost associated with this procedure and even enhance the quality and safety of depurated bivalves destined for human consumption.乳制品中诺如病毒的三种提取方法比较Noroviruses (NoV) are currently the most common cause of viral foodborne diseases and RT-qPCR is widely used for their detection in food because of its sensitivity, specificity and rapidity. The ISO/TS (15216-1, 15216-2) procedures for detecting NoV and HAV in high-risk food categories such as shellfish, bottled water and vegetables were published in 2013. Milk products are less implicated in foodborne viral outbreaks but they can be contaminated with fruit added to these products or by the food handler. Thus, the development of sensitive and reliabletechniques for the detection of NoV in dairy products is needed to ensure the safety of these products. The aim of this study was to develop a RT-qPCR based method for the detection of NoV in milk products. Three methods were tested to recover NoV from artificially contaminated milk and cottage cheese. The selected method was based on the use of proteinase K and the recovery efficiencies ranged from 54.87% to 98.87% for NoV GI, 61.16%–96.50% for NoV GII. Murine norovirus and mengovirus were used as process controls and their recovery efficiencies were respectively 60.59% and 79.23%. The described method could be applied for detecting NoV in milk products for routine diagnosis needs.溶解氧和培养基对空肠弯曲菌形成生物膜的影响Campylobacter jejuni survival in aerobic environments has been suggested to be mediated by biofilm formation. Biofilm formation by eight C. jejuni strains under both aerobic and microaerobic conditions in different broths (Mueller-Hinton (MH), Bolton and Brucella) was quantified. The dissolved oxygen (DO) content of the broths under both incubation atmospheres was determined. Biofilm formation for all strains was highest in MH broth under both incubation atmospheres. Four strains had lower biofilm formation in MH under aerobic as compared to microaerobic incubation, while biofilm formation by the other four strains did not differ under the 2 atm. Two strains had higher biofilm formation under aerobic as compared to microaerobic atmospheres in Bolton broth. Biofilm formation by all other strains in Bolton, and all strains in Brucella broth, did not differ under the 2 atm. Under aerobic incubation DO levels in MH >Brucella> Bolton broth. Under microaerobic conditions levels in MH = Brucella> Bolton broth. Levels of DO in MH andBrucella broth were lower under microaerobic conditions but those of Bolton did not differ under the 2 atm. Experimental conditions and especially the DO of broth media confound previous conclusions drawn about aerobic biofilm formation by C. jejuni. 热-紫外处理对液体食品的灭菌效果优化The combination of ultraviolet radiation and heat (UV-H treatment) has been demonstrated as a promising strategy to overcome the limited UV germicidal effect in fruit juices. Nonetheless, there are so far no data regarding the efficacy of the combined process for the inactivation of bacterial foodborne pathogens in other liquid foods with different pH and composition. In this investigation, the optimum UV-H processing conditions for the inactivation of Escherichia coli, Salmonella Typhimurium, Listeria monocytogenes, and S. aureus in chicken and vegetable broth, in addition to juices, were determined. From these data models that accurately predict the most advantageous UV-H treatment temperature and the expected synergistic lethal effect from UV and heat resistance data separately were constructed. Equations demonstrated that the optimumUV-H treatment temperature mostly depended on heat resistance, whereas the maximum synergistic lethal effect also was affected by the UV resistance of the microorganism of concern in a particular food.肠炎沙门鞭毛对侵袭的作用Nontyphoidal Salmonella strains are the main source of pathogenic bacterial contamination in the poultry industry. Recently, Salmonella entericaserovar Kentucky has been recognized as the most prominent serovar on carcasses in poultry-processing plants. Previous studies showed that flagellaare one of the main factors that contribute to bacterial attachment to broiler skin. However, the precise role of flagella and the mechanism of attachment are unknown. There are two different flagellar subunits (fliC and fljB) expressed alternatively in Salmonella entericaserovars using phase variation. Here, by making deletions in genes encoding flagellar structural subunits (flgK, fliC, and fljB), and flagellar motor (motA), we were able to differentiate the role of flagella and their rotary motion in the colonization of broiler skin and cellular attachment. Utilizing a broiler skin assay, we demonstrated that the presence of FliC is necessary for attachment to broiler skin. Expression of the alternative flagellar subunit FljB enables Salmonella motility, but this subunit is unable to mediate tight attachment. Deletion of the flgK gene prevents proper flagellar assembly, making Salmonella significantly less adherent to broiler skin than the wild type. S. Kentucky with deletions in all three structural genes, fliC, fljB, and flgK, as well as a flagellar motor mutant (motA), exhibited less adhesion and invasion of Caco-2 cells, while an fljB mutant was as adherent and invasive as the wild-type strain.IMPORTANCE In this work, we answered clearly the role of flagella in S. Kentucky attachment to the chicken skin and Caco-2 cells. We demonstrated that the presence of FliC is necessary for attachment to broiler skin. Expression of the alternative flagellar subunit FljB enables Salmonella motility, but this subunit is unable to mediate strong attachment. Deletion of the flgK gene prevents proper flagellar assembly, making Salmonella significantly less adherent to broiler skin than the wild type. S. Kentucky with deletions in all three structural genes, fliC, fljB, and flgK, as well as a flagellar motor mutant (motA), exhibited less adhesion and invasion of Caco-2 cells, while an fljB mutant wasas adherent and invasive as the wild-type strain. We expect these results will contribute to the understanding of the mechanisms of Salmonella attachment to food products.单增李斯特菌可能是通过胃液和体外细胞侵染的主要细菌Various Listeria monocytogenes strains may contaminate a single food product, potentially resulting in simultaneous exposure of consumers to multiple strains. However, due to bias in strain recovery, L. monocytogenes strains isolated from foods by selective enrichment (SE) might not always represent those that can better survive the immune system of a patient. We investigated the effect of cocultivation in tryptic soy broth with 0.6% yeast extract (TSB-Y) at 10°C for 8 days on (i) the detection of L. monocytogenes strains during SE with the ISO 11290-1:1996/Amd 1:2004 protocol and (ii) the in vitro virulence of strains toward the Caco-2 human colon epithelial cancer cell line following exposure to simulated gastric fluid (SGF; pH 2.0)-HCl (37°C). We determined whether the strains which were favored by SE would be effective competitors under the conditions of challenges related to gastrointestinal passage of the pathogen. Interstrain competition of L. monocytogenes in TSB-Y determined the relative population of each strain at the beginning of SE. This in turn impacted the outcome of SE (i.e., favoring survival of competitors with better fitness) and the levels exposed subsequently to SGF.However, strong growth competitors could be outcompeted after SGF exposure and infection of Caco-2 cells by strains outgrown in TSB-Y and underdetected (or even missed) during enrichment. Our data demonstrate a preferential selection of certain L. monocytogenes strains during enrichments, often not reflecting a selective advantage of strains during infection. Thesefindings highlight a noteworthy scenario associated with the difficulty of matching the source of infection (food) with the L. monocytogenes isolate appearing to be the causative agent during listeriosis outbreak investigations.系统模型的建立来描述动物粪便是果蔬感染致病菌的主要途径The majority of foodborne outbreaks in the United States associated with the consumption of leafy greens contaminated with Escherichia coli O157:H7 have been reported during the period of July to November. A dynamic system model consisting of subsystems and inputs to the system (soil, irrigation, cattle, wild pig, and rainfall) simulating a hypothetical farm was developed. The model assumed two crops of lettuce in a year and simulated planting, irrigation, harvesting, ground preparation for the new crop, contamination of soil and plants, and survival of E. coli O157:H7. As predicted by the baseline model for crops harvested in different months from conventional fields, an estimated 13 out of 257 (5.05%) first crops harvested in July would have at least one plant with at least 1 CFU of E. coli O157:H7. Predictions indicate that no first crops would be contaminated with at least 1 CFU of E. coli O157:H7 for other months (April to June). The maximum E. coli O157:H7 concentration in a plant was higher in the second crop (27.10 CFU) than in the first crop (9.82 CFU). For the second crop, the probabilities of having at least one plant with at least 1 CFU of E. coli O157:H7 in a crop were predicted as 15/228 (6.6%), 5/333 (1.5%), 14/324 (4.3%), and 6/115 (5.2%) in August, September, October, and November, respectively. For organic fields, the probabilities of having at least one plant with ≥1 CFU of E. coli O157:H7 in a crop (3.45%) were predicted to be higher than those for the conventional fields (2.15%).O157迫于环境压力的嗜热和苏醒加速进化The development of resistance in foodborne pathogens to food preservation techniques is an issue of increasing concern, especially in minimally processed foods where safety relies on hurdle technology. In this context, mild heat can be used in combination with so-called nonthermal processes, such as high hydrostatic pressure (HHP), at lower individual intensities to better retain the quality of the food. However, mild stresses may increase the risk of (cross-)resistance development in the surviving population, which in turn might compromise food safety. In this investigation, we examined the evolution of Escherichia coli O157:H7 strain ATCC 43888 after recurrent exposure to progressively intensifying mild heat shocks (from 54.0°C to 60.0°C in 0.5°C increments) with intermittent resuscitation and growth of survivors. As such, mutant strains were obtained after 10 cycles of selection with ca. 106-fold higher heat resistance than that for the parental strain at 58.0°C, although this resistance did not extend to temperatures exceeding 60.0°C. Moreover, th ese mutant strains typically displayed cross-resistance against HHP shock and displayed signs of enhanced RpoS and RpoH activity. Interestingly, additional cycles of selection maintaining the intensity of the heat shock constant (58.5°C) selected for mutan t strains in which resuscitation speed, rather than resistance, appeared to be increased. Therefore, it seems that resistance and resuscitation speed are rapidly evolvable traits in E. coli ATCC 43888 that can compromise food safety.肉桂油抑制大肠0157噬菌体的入侵和增殖This study evaluated the inhibitory effect of cinnamon oil against Escherichia coli O157:H7 Shiga toxin (Stx) production andfurther explored the underlying mechanisms. The MIC and minimum bactericidal concentration (MBC) of cinnamon oil against E. coli O157:H7 were 0.025% and 0.05% (vol/vol), respectively. Cinnamon oil significantly reduced Stx2 production and the stx2 mRNA expression that is associated with diminished Vero cell cytotoxicity. Consistently, induction of the Stx-converting phage where the stx2 gene is located, along with the total number of phages, decreased proportionally to cinnamon oil concentration. In line with decreased Stx2 phage induction, cinnamon oil at 0.75× and 1.0× MIC eliminated RecA, a key mediator of SOS response, polynucleotide phosphorylase (PNPase), and poly(A) polymerase (PAP I), which positively regulate Stx-converting phages, contributing to reduced Stx-converting phage induction and Stx production. Furthermore, cinnamon oil at 0.75× and 1.0× MIC strongly inhibited the qse BC and luxS expression associated with decreased AI-2 production, a universal quorum sensing signaling molecule. However, the expression of oxidative stress response genes oxyR, soxR, and rpoS was increased in response to cinnamon oil at 0.25× or 0.5× MIC, which may contribute to stunted bacterial growth and reduced Stx2 phage induction and Stx2 production due to the inhibitory effect of OxyR on prophage activation. Collectively, cinnamon oil inhibits Stx2 production and Stx2 phage induction in E. coli O157:H7 in multiple ways.长时间接触导致增加了产气肠杆菌的食品感染Bacterial cross-contamination from surfaces to food can contribute to foodborne disease. The cross-contamination rate of Enterobacteraerogenes on household surfaces was evaluated by using scenarios that differed by surface type, food type, contact time (<1, 5, 30, and 300 s), and inoculum matrix (trypticsoy broth or peptone buffer). The surfaces used were stainless steel, tile, wood, and carpet. The food types were watermelon, bread, bread with butter, and gummy candy. Surfaces (25 cm2) were spot inoculated with 1 ml of inoculum and allowed to dry for 5 h, yielding an approximate concentration of 107 CFU/surface. Foods (with a 16-cm2 contact area) were dropped onto the surfaces from a height of 12.5 cm and left to rest as appropriate. Posttransfer, surfaces and foods were placed in sterile filter bags and homogenized or massaged, diluted, and plated on tryptic soy agar. The transfer rate was quantified as the log percent transfer from the surface to the food. Contact time, food, and surface type all had highly significant effects (P < 0.000001) on the log percent transfer of bacteria. The inoculum matrix (tryptic soy broth or peptone buffer) also had a significant effect on transfer (P = 0.013), and most interaction terms were significant. More bacteria transferred to watermelon (～0.2 to 97%) than to any other food, while the least bacteria transferred to gummy candy (～0.1 to 62%). Transfer of bacteria to bread (～0.02 to 94%) was similar to transfer of bacteria to bread with butter (～0.02 to 82%), and these transfer rates under a given set of conditions were more variable than with watermelon and gummy candy.。
2017重庆市事业单位食品检验岗位专业考试题库(微生物部分)
2017重庆市事业单位食品检验岗位专业考试题库(微生物部分)重庆市事业单位食品检验岗位专业考试题库（微生物部分）1、答:（1）干热灭菌法将包扎好的玻璃器皿摆入电热烘箱中，相互间要留有一定的空隙，以便空气流通。
关紧箱门，打开排气孔，接上电源。
待箱内空气排出到一定程度时，关闭上排气孔，加热至灭菌温度后，固定温度进行灭菌：160℃—165℃保持2小时。
2小时后切断电源。
待烘箱内温度自然降温冷却到60℃以下后，再开门取出玻璃器皿，避免由于温度突然下降而引起玻璃器皿碎裂。
（2）高压蒸汽灭菌法关好排水阀门，放入纯净水或蒸馏水至标度。
注意水量一定要加足，否则容易造成事故。
将须要灭菌的器材、培养基等装入灭菌锅中，加盖密封。
旋紧螺旋时，先将每个螺旋旋转到一定程度（不要太紧），然后再旋紧相对的两个螺旋，以达到平衡旋紧，否则易造成漏气，达不到彻底灭菌的目的。
通电加温，打开排气活门，排尽锅内的空气。
通常当压力表指针升至5磅或0.05MPa时，打开排气活门放气，待压力表指针降至零点一小段时间后，再关闭活门。
即活门冲出的全部是蒸汽时则表示彻底，此时可关闭排气活门，如果过早关闭活门，排气不彻底，也达不到彻底灭菌的目的。
恒温灭菌:0.1MPa或15磅压力保持20～30分钟。
压力表的指针上升时，锅内温度也逐渐升高，当压力表指针升至0.1MPa时或15磅时，锅内温度相当于120℃～121℃（等于一个大气压），此时开始计算灭菌时间，控制热源，使处于0.1MPa或15磅压力保持20～30分钟，即能达到完全灭菌的目的，然后停止加温。
当达到所需温度时开始计时，并在此温度下保持所需的时间。
降温：自然降温或打开活门排汽降温。
稍微打开一点排气活门，使锅内蒸汽缓慢排除，然后逐渐开大活门，气压徐徐下降，注意勿使排气过快，否则会使锅内的培养基沸腾而冲脱或沾染棉花塞，但排气太慢又使培养基在锅内，受高温处理时间过长，对培养基也是不利的。
一般从排气到打开锅盖以10分钟左右为好。
食品微生物期末考试复习题及答案
绪论一.（1）菌种的分离、培养、接种、染色等研究微生物的技术的发明者是柯赫。
（2）细菌分类鉴定的主要文献是《伯杰氏手册》。
（3）第一个用自制显微镜观察到微生物的学者是列文虎克，被称为微生物学研究的先驱者，而法国学者巴斯德和德国学者柯赫则是微生物生理学和病原菌学研究的开创者。
（4）微生物在现代生物分类系统中分别属于 _真菌界__原核生物界、_原生生物_ 界、__植物界和 _动物__ 界。
二.菌株：又称品系，是指由一个单细胞繁衍而来的克隆或无性繁殖系中的一个微生物或微生物群体。
种：是微生物学分类的基本单位，是一大群表形特征高度相似的、亲缘关系极其接近的，和同属其他种有明显差异的一大群菌株的总称。
双名法：一个物种的学名是由前面一个属名（generic name）和后面一个种名（specific epithet）两部分组成三.1. 微生物的特点有哪些？体积小,面积大;吸收多,转化快; 生长旺盛，繁殖快 ;适应性强，易变异; 种类繁多，分布广3. 食品微生物学是微生物学的一个分支学科，它研究的主要内容是什么？与食品有关的微生物的特性, 食品中微生物与微生物,微生物与食品,微生物、食品和人体之间的相互关系。
微生物以（农副产品）基质为栖息地，快速生长繁殖的同时，又改变栖息地（农副产品）的物理化学性质。
食品原料、食品生产过程、产品包装、贮藏和运输过程中微生物介导的不安全因素及控制.5. 柯赫法则病原微生物来自于患病机体,从患者身上必须能分离到并且可以纯培养;人工接种这种病原微生物的纯培养到正常机体能引起相同的疾病.原核微生物一. 填空题：（1）细菌的繁殖主要靠：二分裂。
（2）放线菌的菌体呈分枝丝状体 , 它是一种丝状原核的微生物。
（3）在细菌细胞中能量代谢场所是细胞膜。
（4）自养细菌中固定 CO2 的场所是 : 羧酶体，蓝细菌中进行光合作用的场所是 : 类囊体，而异形胞是蓝细菌进行固氮的场所。
（5）脂多糖 (LPS) 是革兰氏阴性菌细胞壁外壁层的主要成分，它由特异性多糖，核心多糖 _，类脂A 三部分构成。
宁波大学942食品微生物学2009--2017,2019--2020年初试考研真题
(答案必须写在考点提供的答题纸上)(答案必须写在考点提供的答题纸上)(答案必须写在考点提供的答题纸上)(答案必须写在考点提供的答题纸上)科目代码：942 总分值：150 科目名称：食品微生物学第 1 页共3 页(答案必须写在考点提供的答题纸上)科目代码：942 总分值：150 科目名称：食品微生物学第 2 页共3 页(答案必须写在考点提供的答题纸上)科目代码：942 总分值：150 科目名称：食品微生物学第 3 页共3 页入学考试试题(A卷)(答案必须写在答题纸上)考试科目:食品微生物学科目代码：942 适用专业:食品科学、水产品加工及贮藏工程、食品工程一、概念解释（共30分，每题3分）1、营养缺陷型菌株2、F+菌株3、移码突变4、平酸腐败5、鉴别培养基6、Plasmid7、无氧呼吸8、血清学试验9、朊病毒10、商业无菌二、填空(共26分，每空格1分)1、产甲烷细菌和甲烷氧化菌在生态学上的相互关系称关系；泡菜制作过程中乳酸菌与腐败菌相互竞争，乳酸菌产生乳酸抑制其它腐败菌生长，其生态学上称关系。
2、葡萄糖在生物氧化的脱氢阶段中，可通过4条代谢途径完成其脱氢反应，它们分别是途径、途径、ED途径和循环。
从代谢产物类型来说，色素维生素等属于。
3、细胞质中的异染颗粒为贮藏物，聚Beta-羟丁酸为贮藏物。
4、黄酒酿造中制曲的目的有和；啤酒酿造中麦芽的作用；啤酒酿造主发酵温度；罐藏食品其微生物检验常用的培养温度有和两种。
5、酱油酿造所用典型菌株为，生理上应具有较强的酶活性。
6、下列菌名的中文名称：Aspergillus niger，Saccharomyces cerevisiae，Escherichia coli ，Bacillus subtilius 。
以下每格2分。
7、以淀粉质为主要碳源经发酵形成醋酸时，经过微生物作用的两个阶段分别为和。
8、明胶液化试验的实验原理是：。
三、简述下列概念的区别（共24分，每题4分）1、Complete medium和Minimal medium：2、同型乳酸发酵与异型乳酸发酵：3、微生态平衡与微生态制剂：4、消毒与防腐：5、连续培养和补料分批培养：6、菌相和菌落：第1页，共2 页入学考试试题(A卷)(答案必须写在答题纸上)考试科目:食品微生物学科目代码：942 适用专业:食品科学、水产品加工及贮藏工程、食品工程四、是非题（（对的打“+ ”，错的打“-”；共24分，每题2分）1、嗜酸微生物可以在酸性环境中较好地生长，因细胞内酶系等可以是酸性的。
宁波大学2017年《942食品微生物学》考研专业课真题试卷
科目代码:942科目名称：食品微生物学适用专业:食品科学水产品加工及贮藏工程食品工程一、名词解释（本大题共10题，每小题3分，共30分）1.MM或[—]2.补料培养3.菌落4.孢子囊孢子5.发酵6.选择性培养基7.Anaerobic respiration8.BOD9.微生态制剂10.原生质体二、是非题（本大题共10题，每小题2分，共20分）1．微生物的分离是指从混杂的微生物中得到单一微生物的过程。
()2．某一芽孢细菌其最适生长温度在60℃以上，因此，是一种耐热性细菌。
()3．毒素、色素及维生素等属于微生物次级代谢产物。
()4．营养物质跨膜的主动运送必需依靠载体和能量，而单纯扩散不需要载体和能量。
() 5．梭状芽孢杆菌是一种专性厌氧菌。
()6．细菌的鞭毛和菌毛都是细菌的运动器。
()7．烈性噬菌体侵入细菌并不引起细胞裂解，此现象称溶原性。
()8．抗性突变是通过适应而发生的，即由其所处的环境诱发出来的。
()9．营养缺陷型菌株能在基础培养基和完全培养基上生长，野生型菌株能在完全培养基上生长。
()10．DNA和RNA均可作为遗传信息的载体。
()三、填空题（本大题共10题，每空格1分，共30分）1．革兰氏染色的关键步骤是菌体，G+呈色结果为。
科目代码:942科目名称：食品微生物学适用专业:食品科学水产品加工及贮藏工程食品工程2．高压汽蒸汽灭菌操作的关键是；干热灭菌的操作温度与时间是。
3．同型乳酸发酵主要产物为。
4．生物发酵产能的主要代谢途径有，，，四种。
5．影响微生物生长最重要的因素通常有，，和，其它还有，，等。
6．细胞质中的脂质颗粒是贮藏物；细胞质中的异染颗粒是贮藏物。
7．写出两种以上有机氮源，。
8．原核生物基因重组的方式包括，，，。
9.下列菌名的中文名称：Saccharomyces cerevisiae，Escherichiacoli。
10.微生物与生物环境之间有，，，和捕食五种关系。
四、问答题（本大题共7题，总分70分）1．现有4种菌株，分别是枯草芽孢杆菌，大肠杆菌，金黄色葡萄球菌和产碱杆菌；由于不慎而将标签脱落，请你设计一种完整方法和写出步骤，将这四种微生物加以鉴定。
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沈阳农业大学2017年硕士研究生入学初试试题
考试科目：食品微生物
分值：150分
适用专业：食品加工与安全
注意：答案必须写在答题纸上，写在题签上无效。
一、填空题（共22分，每空2分）
1.细菌的基本结构包括、、、四个部分。
2.革兰氏阴性细菌细胞壁外膜LPS的多糖部分包括和。
3.病毒主要由和两部分构成。
4.微生物产生能量的方式、、。
二、选择题（共18分，每题2分）
1.柠檬酸工业化生产的菌种主要采用（）。
A.米曲霉B古通桥毛霉 C.桔青霉 D.黑曲霉
2.除（）外，下面所有选项都是外源性污染。
A原料 B.包装材料 C.空气 D.机械设备
3.下列微生物中属于兼性厌氧性微生物的是（）。
A酿酒酵母 B.枯草芽孢杆菌 C.链霉菌 D.双歧杆菌
4.不属于食品微生物学研究范畴的是（）。
A.研究与食品有关的微生物的活动规律
B.研究利用有益微生物为人类制造食品
C.研究如何控制有害微生物、防止食品发生腐败变质
D.研究病原微生物造成食物中毒的机理
5.根据GB4789.2-2010中规定的检测方法，稀释100倍的样液中的平板菌落数（cfu/ml）分别为232，244；稀释1000倍的样液中的平板菌落数分别为33，35，请问该样品的菌落总数为（）cfu/ml。
A. 2.4×104
B.3.4×104
C.2.5×104
D.2.3×104
6在紫外诱变中，常常选择处于（）的微生物细胞进行处理。
A.延迟期
B.对数生长期
C.稳定期
D.衰亡期
7. （）是控制菌种退化的主要措施。
A.采用营养丰富的培养基保藏菌种
B.控制传代次数
C.采用营养贫瘩的培养基保藏菌种
8.金黄色葡萄球菌引起的食物中毒主要属于（）。
A.感染型食物中毒
B.毒素型食物中毒
C.混合型食物中毒
9.观察细菌动力常用（）。
A.半固体培养基
B.鉴别培养基
C.液体培养基
D.发酵培养基
三、判断并改错〔共15分，每题3分）
1.氧化磷酸化是微生物体内普遍存在的获得能量的一种方式。
2.大肠菌群检测中如果样品实际稀释倍数是MPN表上稀释倍数的十倍，则检测结果需除以10后进行报告。
3.在菌种分离和筛选过程中，分离纯化是增加目的微生物的关键步骤。
4.罐藏类食品发生由霉菌引起的腐败，则说明罐藏类食品的真空度不够。
5.造成食品腐败变质的微生物主要是以中温型、异养及好氧或兼性厌氧的微生物为主。
四、名词解释（共32分，每题4分）
1.底物水平磷酸化
2.D值
3.基团转位
4.微生物生态
5.食品中微生物的消长
6.大肠菌群
7.染色体缺失
8.营养缺陷型
五、简答题（共48分。
每题8分）
1.浅析污染食品的微生物来源?
2.根据所学基本知识，说明为什么按照GB4789.2—2010中的方法进行检测，所得结果能有效反应食品的卫生质量?
3.温度对微生物生长有什么影响?为什么低温只能保藏食物。
不能作为杀菌的手段?
4.什么是培养基?在发酵工业中发酵培养基配制的基本原则?
5.工业微生物菌种选育后，为什么要进行菌种保藏?方法有哪些?
6.微生物及其代谢产物在食品工业中有哪些应用?
六、论述题（共15分）
浑浊型果汁饮料的生产工艺如下：
原料→清洗→热烫及去皮（95~100℃，1min）→榨汁→过滤→调配→均质→
真空排气→高温瞬时杀菌→装罐密封→冷却、检验、成品入库
（1）请根据生产工艺路线，结合微生物学的基础知识，试分析能有效控制微生物污染的工艺要点? （2）若发生微生物污染，试分析发生污染的原因，及可能污染的微生物类群?。