高转化大豆异黄酮乳酸菌的筛选及在豆乳中的发酵特性

为提高大豆异黄酮生物活性及利用度,该研究以含七叶苷和柠檬酸铁的特殊培养基,从实验室保藏的人源乳酸菌中筛出产β-葡萄糖苷酶目标菌株,并采用高效液相色谱法测定其发酵豆乳转化大豆异黄酮的能力,分析持水力、产酸速率和发酵末活菌数.结果显示,从140株乳酸菌中筛出的12株目标菌株,菌株58和菌株m91发酵豆乳产大豆异黄酮苷元能力...     

发酵香肠发酵过程中菌落总数数学模型的建立

用SAS9．0中的响应曲面试验设计,研究了盐浓度、水分活度、发酵温度、发酵时间和糖浓度等环境因子对发酵香肠发酵过程中细菌总数变化的影响,建立科学的数学模型,此数学模型能够表达发酵香肠发酵过程中细菌总数的变化趋势。用建立的数学模型对发酵过程中的微生物进行了预测,结果可靠。细菌总数与实验测定数据进行比较,平均误差范围是-10．20％～8．43％。此数学模型为发酵香肠发酵过程的控制,提高发酵肉制品的安全性,缩短生产周期提供了依据,也是微生物预报的重要基础。     

利用发光菌测量汽油发动机润滑油生物毒性的试验研究

利用发光菌作为受试物种,参照美国材料与试验学会ASTMD6081和国标GB/T15441进行汽油机润滑油生物毒性的试验研究。介绍了试验所用器材、润滑油水溶性馏分（WSF）和可容纳水馏分（WAF）的制备过程及生物毒性试验方法,对我国目前使用的3种典型的汽油机水冷润滑油进行了发光菌毒性实际检测,试验研究表明,利用发光菌作为汽油机润滑油急性生物毒性检测具有一定的科学性和先进性。试验中发光菌与毒液的接触时间为15-20s,制备WAF过程中转速为1200r/min搅拌时间6h条件下,分别测得3种润滑油WSF的毒性半致死量LD50,参照我国“急性毒性（LD50）剂量分级”3种润滑油相当于大鼠口服半致死量的无毒级别,相当于人的致死量低毒级别。     

钼掺杂铜硅钙石的制备及其抗菌性能和细胞相容性研究

含铜生物材料在高浓度铜离子释放时对细菌有优异的抑制作用,但同时具有细胞毒性;而在低浓度铜离子释放时虽然具有良好的细胞相容性,但其抗菌性能低.因此,开发一种含铜生物材料,使其能够在高浓度铜离子释放情况下同时具有优异抗菌性能和良好细胞相容性,具有重要意义.本研究利用钼和铜之间的拮抗作用原理,采用溶胶-凝胶法制备了钼掺杂铜硅...     

Cloning and Characterization of a Thermostable Endolysin of Bacteriophage TP-84 as a Potential Disinfectant and Biofilm-Removing Biological Agent

The obligatory step in the life cycle of a lytic bacteriophage is the release of its progeny particles from infected bacterial cells. The main barrier to overcome is the cell wall, composed of crosslinked peptidoglycan, which counteracts the pressure prevailing in the cytoplasm and protects the cell against osmotic lysis and mechanical damage. Bacteriophages have developed two strategies leading to the release of progeny particles: the inhibition of peptidoglycan synthesis and enzymatic cleavage by a bacteriophage-coded endolysin. In this study, we cloned and investigated the TP84_28 endolysin of the bacteriophage TP-84, which infects thermophilic Geobacillus stearothermophilus, determined the enzymatic characteristics, and initially evaluated the endolysin application as a non-invasive agent for disinfecting surfaces, including those exposed to high temperatures. Both the native and recombinant TP84_28 endolysins, obtained through the Escherichia coli T7-lac expression system, are highly thermostable and retain trace activity after incubation at 100 °C for 30 min. The proteins exhibit strong bacterial wall digestion activity up to 77.6 °C, decreasing to marginal activity at ambient temperatures. We assayed the lysis of various types of bacteria using TP84_28 endolysins: Gram-positive, Gram-negative, encapsulated, and pathogenic. Significant lytic activity was observed on the thermophilic and mesophilic Gram-positive bacteria and, to a lesser extent, on the thermophilic and mesophilic Gram-negative bacteria. The thermostable TP84_28 endolysin seems to be a promising mild agent for disinfecting surfaces exposed to high temperatures.     

罗801块微生物驱油菌种代谢产物分析

为了研究罗801块微生物驱油菌种代谢产物,从代谢产物化学性质的角度探索驱油作用机理,依据微生物代谢规律,应用气相色谱、气质联用仪(气相色谱-质谱GC-MS)、傅立叶变换红外光谱仪等化学分析仪器和手段,建立了一套通用的驱油菌种代谢产物定性定量分析方法:短链脂肪酸和生物气气相色谱分析,长链脂肪酸、醇类、酚类以及生物烃的预处理和GC-MS分析,醛类、酮类的衍生化及GC-MS分析,生物表面活性物质的薄层层析和红外光谱定性分析,脂类化合物的GC-MS定量分析等;介绍了罗801块驱油菌种代谢产物分析结果:罗801块驱油菌种代谢产物共检出近百种化合物,不同菌种代谢产物种类和数量差异较大。驱油菌种代谢产物分析说明了驱油菌种代谢的复杂性,该研究对矿场试验效果评价及微生物驱油机理探索有重要意义。     

Bottom-Up法计算油田注入水中三种细菌的不确定度

为保持地下压力,在油田开采过程中需向地下油层中注水,注入水中最为常见的三种细菌是腐生菌、铁细菌和硫酸还原菌,这些细菌的存在会降低注入水水质并腐蚀管道,影响油田开采。为客观评价三种细菌检测的准确度,采用绝迹稀释法检测技术,利用Bottom-Up法,通过21组数据对三种细菌检测方法的不确定度进行计算。结果表明,绝迹稀释法检测油田注水三种细菌的不确定度分别为:硫酸还原菌±4 mL^-1,腐生菌±6 mL^-1,铁细菌±16 mL^-1。通过Bottom-Up法对检测不确定度进行评估,可真实、准确地反应油田注入水中三种细菌的实际含量范围,为油田注水达标提供技术保障。     

Atomic-Resolution Structures and Mode of Action of Clinically Relevant Antimicrobial Peptides

Global rise of infections and deaths caused by drug-resistant bacterial pathogens are among the unmet medical needs. In an age of drying pipeline of novel antibiotics to treat bacterial infections, antimicrobial peptides (AMPs) are proven to be valid therapeutics modalities. Direct in vivo applications of many AMPs could be challenging; however, works are demonstrating encouraging results for some of them. In this review article, we discussed 3-D structures of potent AMPs e.g., polymyxin, thanatin, MSI, protegrin, OMPTA in complex with bacterial targets and their mode of actions. Studies on human peptide LL37 and de novo-designed peptides are also discussed. We have focused on AMPs which are effective against drug-resistant Gram-negative bacteria. Since treatment options for the infections caused by super bugs of Gram-negative bacteria are now extremely limited. We also summarize some of the pertinent challenges in the field of clinical trials of AMPs.     

膳食纤维抗肿瘤作用研究

该文在对近年国内外有关膳食纤维研究文献的研究基础上,总结膳食纤维在抗肿瘤方面机理及对食品中致癌物代谢影响。     

黄铁矿烧渣微生物脱硫

在烧渣生物脱硫的试验.论研究了矿浆浓度、Fe³⁺浓度及pH值对游离T.f菌浓度和脱硫率的影响.证明烧渣脱硫是T.f.菌直接浸出作用和由细菌而产生的Fe³⁺间接浸出作用的联合;脱硫速率和菌种氧化活性受到吸附在固相上和液相中细菌生长情况、矿浆浓度、pH值和Fe³⁺的影响;三价铁离子的添加可影响菌种活性,抑制浸出的进行,且易在矿物表面产生沉淀,降低氧化率.烧渣生物脱硫后,可达到铁精矿标准.