Optimization of mixed fermentation technology of Lactobacillus helveticus andLactobacillus rhamnosus based on high viable count

以瑞士乳杆菌和鼠李糖乳杆菌混合发酵培养,利用两菌株细胞代谢的差异,以静置发酵24 h后得到的活菌数目为指标,通过单因素实验和正交实验,研究了瑞士乳杆菌和鼠李糖乳杆菌高活菌数混合发酵的最适发酵条件。结果表明,瑞士乳杆菌和鼠李糖乳杆菌高活菌数混合发酵的最优条件为:发酵温度37℃,初始pH=6.8,接种量6%,瑞士乳杆菌:鼠李糖乳杆菌=1∶2,瑞士乳杆菌优先接种3 h。最终得到乳酸菌总活菌数为7.2×10~9m L~(-1)。与在相同条件下单独发酵的瑞士乳杆菌和鼠李糖乳杆菌活菌数相比,分别提高了1∶8倍和10.2倍。为乳酸菌的高活菌数发酵奠定了基础

Diversity of bacterial community structure and its driving factors in three bays of Bohai Sea

[Background] Sustainable development of coastal ecosystem has become one of the most important concerns for people nowadays. Riverine output and anthropogenic interrupt have important impacts on the coastal environment. [Objective] In this study, we collected 12 samples from three transects including Bohai Bay, Liaodong Bay and Laizhou Bay to explore the microbial community and diversity in summer of 2015. [Methods] DNA was extracted from water samples by using DNA extraction kit. Samples were analyzed by Illumina HiSeq sequencing technology. We compared the differences among these three transects according to the analysis results. [Results] The diversity index and rarefaction curves showed significant differences among these three transects. The order of diversity value was Laizhou Bay>Bohai Bay>Liaodong Bay. The distribution of the dominant community was as follows: the proportion of Proteobacteria, Bacteroidetes, Cyanobacteria, Actinobacteria and Planctomycetes in the Bohai Bay was 39.8%, 25.7%, 22.4%, 5.85% and 4.38%, respectively. The dominant community proportion in Liaodong bay was Proteobacteria (37.8%), Bacteroidetes (25.7%), Cyanobacteria (17.8%), Actinobacteria (10.4%) and Planctomycetes (5.64%). While in Laizhou Bay there were only four dominant communities as follows: Proteobacteria (59.0%), Bacteroidetes (17.5%), Cyanobacteria (8.2%), Actinobacteria (7.88%). By using the principal component analysis (PCA) and Heatmap correlation analysis, we found that environmental factors were key roles in controlling the microbial diversity in the Bohai Sea. Among them, the concentration of nitrate was particularly significant according to the Mantel test analysis. [Conclusion] The microbial diversity in the three bays of Bohai Sea was very rich and multifarious. The population structure and species in the Laizhou Bay is the most complex and abundant among these three bays, and then it is Bohai Bay and Liaodong Bay. There was a significant correlation among microbial diversity, environmental factors and the spatial distribution. Above all, this study will provide a theoretical basis for further protection and ecological development of Bohai Sea

Microbial Degradation of Petroleum Hydrocarbons by Acinetobacter sp. BZ-15,Isolated from Contaminated Soil

本研究旨在从土壤中筛选高效石油烃降解菌株,并对其系统分类和降解特性进行研究,为石油污染的原位修复奠定基础.该研究从滨州油井溢油污染土壤样品中分离得到一株高效石油烃降解菌株BZ-15,对菌株BZ-15进行形态观察、16S r RNA基因序列分析及系统发育树分析;对该菌株的生长特性进行研究;通过GC-MS分析其对原油组分中不同碳原子饱和烃的降解特性;同时研究吐温-20对其生长及降解特性的影响;对该菌株中的烷烃羟化酶基因alk M进行了克隆.结果表明,菌株BZ-15为不动杆菌属(Acinetobacter sp.)细菌,在LB培养基中其代时为3.25 h,添加吐温-20代时为2.67 h,吐温-20..

海洋芽孢杆菌、海洋右旋糖苷酶及其应用

本发明的提供了一种海洋芽孢杆菌，将其应用于药物开发、日用化妆品、中，拓展了生物医疗微生物的范围。通过在海洋芽孢杆菌(Bacillus?sp.)L-1中提取分离出海洋右旋糖苷酶的基因及其表达翻译的右旋糖苷酶，与其它的右旋糖苷酶相比，本发明所述的海洋右旋糖苷酶来源于海洋低温高盐环境，该酶在25~30℃海水中具有很高的右旋糖苷降解效率，常温下就可以发挥作用，而且40℃以上极不稳定，中温就可以使酶失活，从而确保了其安全性

短小芽孢杆菌、分离方法、糖脂类表面活性剂制备方法

本发明提供了一种短小芽孢杆菌，所述芽孢杆菌的保藏号为CCTCC?M2015438。本发明的提供的短小芽孢杆菌，具有降解石油组分和产生表面活性剂的双功能，拓展了生物医疗微生物的范围。本发明提供的糖脂类表面活性剂的制备方法，采用海水加营养物配置成廉价寡养培养基，进行海洋细菌短小芽孢杆菌L-2菌株的产生物表面活性剂糖脂发酵，有效降低了发酵成本

海洋芽孢杆菌、分离方法、海洋右旋糖苷酶制备方法及应用

本发明提供了一种海洋芽孢杆菌，所述芽孢杆菌的保藏号为CCTCC?M2015437。本发明应用于上述海洋芽孢杆菌制备得到海洋右旋糖苷酶，对变异链球菌具有抑制其生物膜形成的功能，除了可以应用于龋齿防治及在医疗，日化等方面以外，对海洋生物医药等方面也具有巨大的应用潜力

钙离子信号转导及其调控机制

Calcium ions (Ca 2+ ) is an important intracellular second messenger, and regulates many physiological processes. As the second messenger, a gradient of cytoplasmic Ca 2+ and intracellular calcium pool or extracellular Ca 2+ concentration is required. When certain stimuli causes an increase of intracellular Ca 2+ concentration, Ca 2+ will bind to downstream protein receptors and transmit the signal. The function and regulation mechanism of Ca 2+ are well studied in eukaryotes. However, calcium signal regulation in bacte ria is far behind that in eukaryotes. At present, Ca 2+ is also found to be the most important second messenger in bacteria. It is involved in the regulation of temperature sensing mechanism, chemotaxis, cell motility, phototaxis, heterocyst differentiation, spore formation and stress resistance of bacteria. Although calcium signaling has been found in prokaryotes, the specific regulatory mechanism remains unclear. This review summarizes the related studies of calcium signal regulation in order to provide reference for further revealing the biological regulation function and mechanism of calcium signal in bacteria

一种降解石油的复合菌剂及其制备方法与应用

一种降解石油的复合菌剂，其特征在于，包括威尼斯不动杆菌LCL?1与迪茨氏菌CN?3，所述威尼斯不动杆菌与所述迪茨氏菌的活菌数比例为1~50:10~200，所述威尼斯不动杆菌LCL?1的保藏单位名称为中国典型培养物保藏中心(CCTCC)，保藏号为M?2015538；所述迪茨氏菌CN?3的保藏单位名称为中国典型培养物保藏中心，保藏号为M?2015537。上述降解石油的复合菌剂，从石油污染的土壤中分离的不动杆菌属和迪茨氏菌属，具有高效的石油降解能力，且两种菌种之间具有很好的协同作用，可以通过菌株间的共生、互生等关系，从而弥补单一菌剂降解率低的缺点，大大提高了石油降解能力。此外，还提供该复合菌剂的制备方法与该复合菌剂在石油降解方面的应用

高效石油烃降解菌不动杆菌(Acinetobacter sp.BZ-15)的筛选、鉴定及其降解性能研究

本研究旨在从土壤中筛选高效石油烃降解菌株,并对其系统分类和降解特性进行研究,为石油污染的原位修复奠定基础.该研究从滨州油井溢油污染土壤样品中分离得到一株高效石油烃降解菌株BZ-15,对菌株BZ-15进行形态观察、16S r RNA基因序列分析及系统发育树分析;对该菌株的生长特性进行研究;通过GC-MS分析其对原油组分中不同碳原子饱和烃的降解特性;同时研究吐温-20对其生长及降解特性的影响;对该菌株中的烷烃羟化酶基因alk M进行了克隆.结果表明,菌株BZ-15为不动杆菌属(Acinetobacter sp.)细菌,在LB培养基中其代时为3.25 h,添加吐温-20代时为2.67 h,吐温-20可促进菌株BZ-15生长;该菌株可降解C13~C28碳链长度饱和烃,饱和烃降解率为61.0%,添加吐温-20饱和烃降解效率为52.2%,吐温-20可抑制菌株BZ-15降解饱和烃;菌株BZ-15存在烷烃羟化酶基因alk M,通过末端氧化途径对饱和烃进行降解

细菌的群体感应及其对植物的跨界信号调控

Quorum sensing (QS) is a form of signal communication that exists widely between organisms. It depends on the pop ulation density of bacteria and regulates the behavior of bacteria according to the concentration of signal molecules secreted by bacteria. Bacteria use QS system to carry out intracellular and interspecific signal communication, and participate in various biological functions of bacteria, including the regulation of bioluminescence of marine luminescent bacteria, the production of pathogenic factors of animal and plant pathogenic bacteria, and the symbiosis between rhizobium and plants. Recent studies have shown that the communication be tween prokaryotes and eukaryotes can also generate and release small molecular compounds, establish a signal pathway for communica tion and further affect the expression regulation of each other&rsquo;s genes. This process is called transboundary signal communication. The QS signaling molecules secreted by bacteria can be sensed by the host plant, and the plant can induce a systemic defense response, se crete an analog of the bacterial quorum sensing signal molecule, or produce an enzyme that degrades the signal molecule such as the bacterial N-acyl homoserine lactone, which can influence bacterial quorum sensing, thereby mediating bacterial-plant cross-border signal communication. In this paper, the latest research progress of bacterial QS signal molecular regulation system and its mediated bacteria-plant information communication was reviewed, in order to provide reference for the research of microbial intraspecies, inter specific and inter-plant cross-border signal regulation</p