Monitoring non-carbonated (‘still’) mineral waters for aerobic colonization

Fifty samples each of two leading brands of French, non-carbonated (‘still’) mineral waters, packed in plastic bottles, were stored in the dark for one month at approximately 20°C to allow marked proliferation of their autotrophic microbial flora. Upon completion of this challenge test 1250 ml per bottle were filtered through five membranes, which were subsequently cultured on 1/10 strength nutrient agar for 48 h at a temperature favouring the growth of thermotrophic organisms only, i.e. 42 ± 0.5°C. The numbers of colonies per one litre were below 10³ in all samples and did not exceed 200 in 56–80%, depending on the brand. Identification of the isolates demonstrated strong inhibition of the psychrotrophic. Gram-negative types, predominating in the association flora of stored still waters and preponderance of Gram-positive, catalase-positive, facultatively anaerobic cocci. Consequently, a Reference Value for the thermotrophic autotrophic colony count per 1 ml in still, commercial mineral waters of the order m = 1 and M = 5 seems justified. It is emphasized that, besides examining for these trivial organism, the usual tests for marker bacteria (Escherichia coli and Lancefield group D streptococci) and Pseudomonas aeruginosa should always be carried out.     

基于细菌觅食机理改进粒子群算法的研究

粒子群算法与细菌觅食算法在优化问题中均体现了较好的性能,但由于各自特定的进化机制,也都存在缺点。粒子群优化（PSO）算法在优化过程中过快陷入局部极值,为了避免这个缺陷,提出了一种新的混合算法。通过PSO算法完成整个空间的全局搜索,通过细菌觅食算法（BFOA）中的趋向性运动算子完成局部搜索的功能,再通过典型函数进行测试,结果表明新算法可以有效弥补细菌觅食算法速度不快和粒子群算法精度不高的缺陷,同时部分地避免了局部收敛的问题,从而适用于解决复杂函数的优化问题。     

硫酸盐还原菌腐蚀的微生物防治研究进展

综述了硫酸盐还原菌腐蚀领域的微生物防治措施的研 究进展，并对微生物菌种的选择、防治机理以及应用等方面进行了探讨.     

一株秸秆纤维素降解菌株的筛选及其降解特性

纤维素是自然界一种最重要的可再生资源,本文从玉米地土壤中分离出 1 株产纤维素酶能力较强的菌株J-N3。以羧甲基纤维素为唯一碳源的分离培养基和刚果红染色法进行初筛,再将筛选到的菌株进行液体发酵培养并测定酶活。结合形态学特征与分子生物学鉴定结果得知,菌株J-N3为芽孢杆菌属( Bacillus)。并对其酶学性质进行初步研究,得到酶最适pH为6.0时,最适反应温度为50 ℃。玉米秸秆经菌株 J-N3处理20 d 时,秸秆失重率及纤维素分解率分别达到26.22%、31.01%。     

The Inflammatory Profile of Obesity and the Role on Pulmonary Bacterial and Viral Infections

Obesity is a globally increasing health problem, entailing diverse comorbidities such as infectious diseases. An obese weight status has marked effects on lung function that can be attributed to mechanical dysfunctions. Moreover, the alterations of adipocyte-derived signal mediators strongly influence the regulation of inflammation, resulting in chronic low-grade inflammation. Our review summarizes the known effects regarding pulmonary bacterial and viral infections. For this, we discuss model systems that allow mechanistic investigation of the interplay between obesity and lung infections. Overall, obesity gives rise to a higher susceptibility to infectious pathogens, but the pathogenetic process is not clearly defined. Whereas, viral infections often show a more severe course in obese patients, the same patients seem to have a survival benefit during bacterial infections. In particular, we summarize the main mechanical impairments in the pulmonary tract caused by obesity. Moreover, we outline the main secretory changes within the expanded adipose tissue mass, resulting in chronic low-grade inflammation. Finally, we connect these altered host factors to the influence of obesity on the development of lung infection by summarizing observations from clinical and experimental data.     

Dynamics of Bacterial Community Structure in the Rhizosphere and Root Nodule of Soybean: Impacts of Growth Stages and Varieties

Bacterial communities in rhizosphere and root nodules have significant contributions to the growth and productivity of the soybean (Glycine max (L.) Merr.). In this report, we analyzed the physiological properties and dynamics of bacterial community structure in rhizosphere and root nodules at different growth stages using BioLog EcoPlate and high-throughput sequencing technology, respectively. The BioLog assay found that the metabolic capability of rhizosphere is in increasing trend in the growth of soybeans as compared to the bulk soil. As a result of the Illumina sequencing analysis, the microbial community structure of rhizosphere and root nodules was found to be influenced by the variety and growth stage of the soybean. At the phylum level, Actinobacteria were the most abundant in rhizosphere at all growth stages, followed by Alphaproteobacteria and Acidobacteria, and the phylum Bacteroidetes showed the greatest change. But, in the root nodules Alphaproteobacteria were dominant. The results of the OTU analysis exhibited the dominance of Bradyrhizobium during the entire stage of growth, but the ratio of non-rhizobial bacteria showed an increasing trend as the soybean growth progressed. These findings revealed that bacterial community in the rhizosphere and root nodules changed according to both the variety and growth stages of soybean in the field.     

Effects of sulfate-reducing bacteria on the corrosion behavior of carbon steel

The influences of the growing process of sulfate-reducing bacteria (SRB) in seawater system on the medium state and corrosion behavior of carbon steel were studied by detecting solution state parameters and using corrosion electrochemical methods. The growing process of SRB in the seawater shows the three stages of growing, death and residual phases. The solution state parameters of the concentration of sulfide, the pH value and the redox potential changed during the three stages of the SRB growing process. And the corrosion rate of D36 carbon steel was accelerated during the growing phase and stable during the death and residual phases. The results indicate that the medium state and the corrosion rate of the steel do not depend on the number of active SRB, but depend on the accumulation of the metabolism products of SRB.     

高分子金属配合物发光材料的制备技术进展

高分子金属配合物发光材料是一类很有价值的功能材料,评述了有关它的各种合成方法。以金属离子与含配位基团的聚合物进行反应,容易在高聚物之间形成交联,难以获得发光强度高的高分子配合物;使金属离子与高分子配体和小分子配体同时作用,可以得到荧光强度比较理想的产物,但反应难以定量控制;以小分子金属配合物单体与某些单体之间进行共聚合反应,也可获得荧光强度较高的高分子配合物,但聚合反应的空间位阻较大;通过两端都含有配位基团的刚性链的有机小分子配体直接与金属离子配合形成高分子金属配合物;以小分子金属配合物单体进行均聚或者将小分子金属配合物接枝到高聚物上也可以形成高分子金属配合物。     

免水型生态卫生设施用降解菌的分离筛选

本文对免水型生态卫生设施中的生物填料及施有机肥农田的土壤进行了人类粪便降解菌的分离。筛选得到的各菌种在实验条件下，降解粪便效果较好，除臭除味，COD下降率在30％左右。其中在土壤中分离出来的9号菌，COD下降率达41％，全部菌种复合培养处理的下降率高达59％。结果表明，实验采用的分离筛选方法是比较有效的，筛选得到了具有较好降解效果的菌种，为降解菌的进一步试验打下了基础。     

离散型细菌觅食算法求解TSP

旅行商问题(TSP)是组合优化问题的典型代表,针对TSP的求解提出一种离散型细菌觅食(DBFO)算法.该算法通过结合2-opt算法设计了一种适合处理离散型变量的趋化算子,将细菌觅食算法推广到了离散情形.同时,结合TSP的特点,在迁徙算子中引入基因库的思想来指导新个体的生成,提高了算法的搜索效率.通过对TSPLIB标准库中22个实例进行仿真实验.实验结果表明,该算法能够有效求解城市规模500以下的TSP,与混合蚁群算法和离散型萤火虫群算法相比,具有更好的全局收敛性和稳定性.