浅谈微生物菌种保藏方法

简要介绍常用微生物菌种的保藏方法及优缺点比较,同时结合多年微生物检验工作经验,以期为微生物菌种的保藏提供参考.     

厌氧管斜面法保藏菌种初探

对用厌氧管斜面法保藏工业菌种，进行了培养存活、形态及其活性的检测。在厌氧管斜面培养斜面培养基中保藏５年的供试菌种，经活化后均能生长，且存活率高，具有原种的典型菌种形态和生理特征，不发生污染。     

酿酒小曲菌种的保藏及复壮

小曲是生产小曲酒的糖化发酵剂.菌种保藏不当会引起其性能的衰退,以致变异.介绍了酿酒小曲菌种根霉、酵母常用的保藏方法.短期保藏可采用低温斜面试管保藏法或液体试管保藏法等,且以橡胶塞斜面试管保藏法较好;长期保藏可采用液体石蜡保藏法、真空冷冻干燥保藏法、液氮罐超低温保藏法等,以真空冷冻干燥保藏法较好.茵种分离复壮中应注意活化液的选择、分离操作方法及有效茵种的选择等.     

食品检验中的菌种保藏方法

综述了食品检验中常用的菌种保藏方法,包括定期移植保藏法、液体石蜡保藏法、载体保藏法、低温保藏法和冷冻干燥保藏法,旨在为食源性致病菌菌种的保藏提供参考。     

介绍一种简便的菌种保藏方法

介绍一种简便的菌种保藏方法江西海泉生物工程公司（336000）钟启平随着饲料工业的发展，固态发酵技术在活性酵母饲料和其它一些饲料产品的生产中得到了迅速的推广和发展，菌种退化则是一些介业经常发生的事。这里介绍一种菌种维护与保藏方法，经多年的实践，证明它非常简...     

微生物菌种保藏的进展

微生物菌种是从事微生物学教学、科研和生产的基础。近年来,随着人们对微生物学研究的深入,微生物正为人类创造了日益增多的福利,微生物菌种已成为国家的一项宝贵的生物资源。微生物菌种保藏也引起人们极大的重视。     

云南葡萄酒产区酵母多样性及特色菌种酿酒应用研究进展

酵母菌的分布与地理位置和气候条件等密切相关,我国葡萄酒产区主要位于35~40 ° N,仅在云南有很小一部处于28~30 ° N。该产区具有复杂的地形地貌和丰富的气候类型,这为优质酵母种质资源的研究和开发提供了优越条件。本文主要对云南葡萄酒产区酵母多样性以及特色菌种酿酒应用研究进行综述,以期对本土葡萄酒酵母资源的开发及特色葡萄酒的生产提供参考。     

苹果酒酿造中的苹果酸-乳酸发酵

在苹果酒酿造中进行苹果酸-乳酸发酵,乳酸菌通过分解苹果酸,产生乳酸,引起其他有机酸的变化,使苹果酒的口感、质量得以改善。pH、温度、SO_2、酒度通过影响乳酸菌的活动而影响苹果酸-乳酸发酵的进行。保证苹果酒苹果酸-乳酸发酵进行的条件为:温度16～18℃,总SO_2含量<70mg/L,pH<3.70,酒精体积分数低于13％。     

Differential synthesis of fermentative aroma compounds of two related commercial wine yeast strains

The specific impact of the yeast strain on the wine flavour and aroma has not been well characterised yet because this effect is usually combined with other variables during the winemaking. In this study, the contribution to wine flavour of two Saccharomyces cerevisiae strains widely used in wine production, VIN13 and EC1118, was evaluated after fermentation at 15 °C. Chemical defined grape juice media fermented with the EC1118 strain showed higher solvent, fatty and pineapple aroma attributes, while that fermented with the VIN13 strain exhibited higher banana, fruity, yeasty and green attributes. Sensorial and chemical analyses evidenced that the production of flavour-active compounds is significantly affected by the yeast strain, as well as by the temperature of fermentation, as shown by comparing the former data with those from fermentations carried out at 28 °C under identical culture conditions.     

Genetic screening of lactic acid bacteria of oenological origin for bacteriocin-encoding genes

A total of 330 lactic acid bacteria isolated from South African red wines during alcoholic and malolactic fermentations and 9 commercial malolactic bacteria starter cultures were screened for antimicrobial activity. Of the entire screened isolates, 26 strains, belonging to the species Lactobacillus plantarum, Lactobacillus paracasei, Lactobacillus hilgardii and Oenococcus oeni, showed activity towards various wine-related and non-wine-related indicator strains. A PCR-based screening revealed the presence of the plantaricin encoding genes plnA, plnEF, plnJ and plnK in five selected Lb. plantarum strains. Furthermore, a co-culture experiment with Lb. plantarum and Enterococcus faecalis was performed. A complete inhibition of cell growth of Ent. faecalis was observed within 72 h. Four putative bacteriocin-encoding genes in the genome of O. oeni were identified and sequenced.     

Kinetics of sugars, organic acids and acetaldehyde during simultaneous yeast-bacterial fermentations of white wine at different pH values

Successfully inducing malolactic fermentation in the production of grape wines can be challenging, especially in wines with multiple inhibitors such as low pH values and high ethanol concentrations. In the present study, the kinetics of several chemicals of enological relevance was studied in Chardonnay vinified by traditional, consecutive alcoholic (AF) and malolactic fermentations (MLF), and simultaneous AF/MLF, where bacteria were co-inoculated with yeast. The Chardonnay must was adjusted to four pH values (3.2, 3.35, 3.5 or 3.65), and the concentrations of sugars, organic acids as well as acetaldehyde were followed throughout the fermentations. The degradation of glucose and fructose was slower at the lowest must pH value (3.2) but independent from the time point of bacterial inoculation. In all cases, malolactic conversion was faster after yeast-bacterial co-inoculation and was completed in simultaneous treatments at pH values of 3.35-3.65, and consecutive treatments at pH 3.5 and 3.65. No statistically significant difference was observed among the final acetic acid concentrations among all inoculation and pH treatments, but there was a trend towards higher acetic acid residues in wines produced by co-inoculation, especially at high pH values. Overall, simultaneous AF/MLF allowed for greatly reduced fermentation times, but the must pH remained a strong factor for fermentation success and determined the final concentration of various wine components. The time point of inoculation influenced formation and degradation kinetics of organic acids and acetaldehyde considerably, and these are of relevance for vinification decisions.     

葡萄酒中的生物胺的生产与工艺控制

生物胺存在于多种发酵食品中,人体吸收过量的生物胺后会引起不良的生理反应,在葡萄酒苹果酸－乳酸发酵（MLF）过程中,有些乳酸菌能够对氨基酸脱羧产生生物胺。利用PCR与DNA探针技术能够快速检测葡萄酒中的组胺产生菌。工艺上采用接种进行MLF,并在MLF完成后对乳酸菌进行有效清除,可以显著降低葡萄酒中生物胺的含量。     

制备冷冻干燥乳酸菌的相关影响因素的研究进展

从技术和经济角度出发,让乳酸菌在干燥及其后续的贮藏过程中,尽可能多的存活是非常重要的。这篇文章主要综述与冷冻干燥乳酸菌制备的几个相关因素。     

ASSESSMENT OF POTENTIAL PROBIOTIC PROPERTIES OF LACTIC ACID BACTERIA AND YEAST STRAINS

ABSTRACT

Four lactic acid bacteria (LAB) and three yeast strains isolated from a traditional Bulgarian cereal-based fermented beverage were assessed for potential probiotic properties. Acid and bile resistance, antipathogenic activity and antibiotic resistance of the strains were evaluated. Tolerance to low pH values (2.0–3.0) and high bile concentrations (0.2–2.0%) of the LAB and yeast strains varied, but all strains kept viable throughout the experiments. Antagonistic activity towards most of the eight test-pathogens was observed for one LAB (Lactobacillus plantarum B28) and two yeast strains (Candida rugosa Y28 and Candida lambica Y30). Antibiotic resistance (39 antibiotics) of the LAB strains was variable, but showed their potential for therapeutic application.     

The inhibitory effects of wine phenolics on lysozyme activity against lactic acid bacteria

The lysozyme of hen's egg white is used in winemaking to control spontaneous lactic acid bacteria (LAB). A total of eight LAB strains, isolated from grape must and wine, were used to assess the inhibitory effects of wine phenolics on lysozyme activity. The presence of phenolics, extracted from grape pomace, in growth medium reduced the mortality rate due to the lysozyme activity. This effect was especially clear in the case of strains belonging to Lactobacillus uvarum, Pediococcus parvulus and Oenococccus oeni, which are more sensitive to lysozyme than L. plantarum and L. hilgardii strains. Cell lysis assays carried out on four strains sensitive to lysozyme and Micrococcus lysodeikticus ATCC 4698, used as a reference strain, confirmed the inhibition of grape pomace phenolics on the muramidase. There was no interference from non-flavonoids, flavanols and flavonol compounds, when they were tested individually, on the lysozyme activity against the strains. Anthocyanins extracted from grape skins slightly inhibited the activity only against M. lysodeikticus. However, proanthocyanidins extracted from seed berries, strongly inhibited the lysozyme. In this extract, dimers were the predominant oligomers of flavan-3-ol. The study demonstrated that the effectiveness of lysozyme against LAB in red winemaking is related to the amount of low molecular weight proanthocyanidins that are released when the grapes are macerating.     

乳清酒的酿制

主要研究利用啤酒酵母进行发酵,生产起泡乳清酒,通过研究确定其发酵条件。     

ASSESSMENT OF POTENTIAL PROBIOTIC PROPERTIES OF LACTIC ACID BACTERIA AND YEAST STRAINS

Four lactic acid bacteria (LAB) and three yeast strains isolated from a traditional Bulgarian cereal-based fermented beverage were assessed for potential probiotic properties. Acid and bile resistance, antipathogenic activity and antibiotic resistance of the strains were evaluated. Tolerance to low pH values (2.0-3.0) and high bile concentrations (0.2-2.0%) of the LAB and yeast strains varied, but all strains kept viable throughout the experiments. Antagonistic activity towards most of the eight test-pathogens was observed for one LAB (Lactobacillus plantarum B28) and two yeast strains (Candida rugosa Y28 and Candida lambica Y30). Antibiotic resistance (39 antibiotics) of the LAB strains was variable, but showed their potential for therapeutic application.