酱香型高温大曲中功能菌B3-1菌株的分离、选育及其分类学鉴定

以酱香型白酒生产所使用的高温大曲为含菌样品，经分离获多株耐高温细菌，对它们进行生化及香气特征测定，确认B3—l菌株为主要功能菌。经形态特征、生理生化特征的测定，B3—l菌株归属于地衣芽孢杆菌。     

纳豆菌的研究和应用

主要介绍了近年来对纳豆菌、纳豆以及纳豆激酶的一些研究进展,并论述了研究和应用开发纳豆菌产品的前景和存在的问题.     

Inactivation of spores of Bacillus cereus in cheese by high hydrostatic pressure with the addition of nisin or lysozyme

The objective of this work was to study high hydrostatic pressure (HHP) inactivation of spores of Bacillus cereus ATCC 9139 inoculated in model cheeses made of raw milk, together with the effects of the addition of nisin or lysozyme. The concentration of spores in model cheeses was approximately 6-log10 cfu/g of cheese. Cheeses were vacuum packed and stored at 8 degrees C. All samples except controls were submitted to a germination cycle of 60 MPa at 30 degrees C for 210 min, to a vegetative cells destruction cycle of 300 or 400 MPa at 30 degrees C for 15 min, or to both treatments. Bacillus cereus counts were measured 24 h and 15 d after HHP treatment. The combination of both cycles improved the efficiency of the whole treatment. When the second pressure-cycle was of 400 MPa, the highest inactivation (2.4 +/- 0.1 log10 cfu/g) was obtained with the presence of nisin (1.56 mg/L of milk), whereas lysozyme (22.4 mg/L of milk) did not increase sensitivity of the spores to HHP. For nisin (0.05 and 1.56 mg/L of milk), no significant differences were found between counts at 24 h and 15 d after treatment. Considering that mesophilic spore counts usually range from 2.6 to 3.0 log10 cfu/ml in raw milk, HHP at mild temperatures with the addition of nisin may be useful for improving safety and preservation of soft curd cheeses made from raw milk.     

枯草杆菌中性蛋白酶基因的表达

本文研究了中性蛋白酶基因在不同宿主菌及各种培养条件下的蛋白酶表达水平。用含有中性蛋白酶基因的重组质粒ＰＭＰＲ４，ＰＭＰＲ８和ＰＭＰＲ１６转化ＢａｃｉｌｌｕｓｓｕｂｔｉｌｉｓＢＧ２０３６，ＢａｃｉｌｌｕｓｓｕｂｔｉｌｉｓＡＳ１．３９８和ＢａｃｉｌｌｕｓｓｕｂｔｉｌｉｓＭＬ，对转化菌产生的蛋白酶活性分析表明：三个重组质粒的导入，均使主菌的酶活性有大幅度的提高。其规律是：宿主菌的蛋白酶活性越低，提高的幅     

Bacillus cereus and Bacillus stearothermophilus Spore Inactivation in Batch and Continuous Flow Systems

Thermal inactivation kinetics were evaluated in batch and continuous flow systems using phosphate buffer between 99 and 107°C for Bacillus cereus T and 128.5 and 139°C for Bacillus stearothermoohilus ATCC 12980 spores. z_D-Values for B. cereus spores in batch aid continuous flow systems were not significantly different; the continuous flow system was more lethal than the batch system. z_D-Values obtained using B. stearothermophilus spores in batch and continuous flow systems were different; the batch system was more lethal than the continuous flow system. Thus, use of batch generated data to predict or design continuous flow processes may not be accurate.     

中性蛋白酶B．S．HD401生产菌激光选育

本文报道了从花生地土壤分离到一株分泌中性蛋白酶的枯草芽孢杆菌，经纯铜蒸汽激光诱变，选育到一株高产菌株ＨＤ４０１，产酶提高幅度高达７２．７％。诱变过程说明，菌体存活率和正变率以及激光波长、孢子体生理状态有一定的相关性。Ｂ．Ｓ．ＨＤ４０１经多次传代，产酶性状稳定，通过正交试验对培养基进行优化，在２升罐中酶活达８５２０ｕ／ｍｌ。     

尼生素协同超高压处理对枯草芽孢杆菌存活率的影响

目的:本实验研究了尼生素协同超高压处理对枯草芽孢杆菌存活率的影响.方法:采用响应曲面方法中的Pentagonal模式,对超高压处理枯草芽孢杆菌进行了实验优化设计,并进行了实验分析.结果:(1)压力、尼生素是超高压灭活枯草芽孢杆菌显著影响因子;(2)在本实验条件范围内建立的超高压杀灭枯草芽孢杆菌的回归模型有效,并可用于预测本实验条件范围内以及附近取值的枯草芽孢杆菌超高压杀菌结果;(3)添加尼生素比增加温度能更有效地协同超高压杀灭枯草芽孢杆菌;(4)在添加0.05mg/ml的尼生素基础上继续增加尼生素浓度,杀灭枯草芽孢杆菌效果不断提高,但增加速度不明显.     

产碱性蛋白酶的嗜热菌株筛选及发酵条件研究

在河南商丘盐碱地堆肥土壤样中分离到1株产碱性蛋白酶的嗜热菌株SR-15,经鉴定为枯草芽孢杆菌(Bacillus subtilis)。摇瓶发酵研究表明,其适宜培养条件为:玉米粉40g/L,黄豆粉40g/L,MgSO40.5g/L,NaCl10g/L,K2HPO41.0g/L,起始pH10.0,培养温度45℃,摇瓶转速190r/min,250mL三角瓶的装液量100mL,48h后发酵液酶活为1180U/mL。     

纳豆菌蛋白酶水解玉米醇溶蛋白制备血管紧张素转化酶抑制肽

利用纳豆菌固态发酵产酶酶解玉米醇溶蛋白,酶解物经SephadexG-25分离纯化,对产物及其组分血管紧张素转化酶(ACE)抑制活性进行检测。结果表明,酶解血管紧张素转化酶的抑制活性为77.83%,经分离后组分3的抑制效果最好,可达89.4%。     

一株石油烃降解菌纺锤芽孢杆菌的分离鉴定及其降解率环境影响因素研究

A hydrocarbon degrading bacterium KL2-13 was isolated from ten sites of oil contaminated soil in the Karamay oilfield. It was identified as the Bacillus fusiformis sp. bacterium based on its morphological and physiological characteristics and the 16S rDNA sequence analysis. The factors influencing the hydrocarbon degradation by the bacterium KL2-13 were determined. The test results have showed that the hydrocarbon degrading bacterium KL2-13 requires an optimum pH range of 6-8, and the optimum inoculation quantity is 3%. The low-concentration metal ions Fe2+, Mg2+ and Ca2+ can improve the degradation ability of the bacteria KL2-13.Atoo low concentration of Tween-80 does not show obvious promotion to the de- grading bacterium KL2-13, and an excessively high concentration can decrease the degradation ability of the bacterium, the best dosage of which is 2%. The hydrocarbon degrading rate reached 59.07%±0.37% under the optimum culture conditions.