蒸发冷却水质问题的分析研究

蒸发冷却空调是以水作为制冷剂,通过在西北地区的实际工程应用,发现存在着蒸发冷却器表面结水垢以及细菌滋生等水质问题.本文针对这两大问题,从产生的原因、条件以及环境等方面进行了分析;阐述了导致上述两大问题的关键原因,提出从补水、流失水比例、水系统的软化以及抗菌剂的填加等几个环节加强水质管理的措施;通过全面的分析和研究,认为蒸发冷却器不会产生军团病.     

永平铜矿酸性矿坑水中的浸矿细菌培养试验研究

通过分离、驯化、组合菌种并制作生长曲线等系列试验过程，详细研究了浸矿细菌转化铁、硫的能力随不同试验进程的变化情况，在此基础上探讨了细菌的生理习性及培养过程中的影响因素。     

利用基因工程菌修复富营养化水体

以徐州市黄河故道应用基因工程菌修复富营养化水体为研究对象，对水体中富营养化指标进行了测定，并对水体中生物生长变化情况进行了观察，试验和分析了基因工程菌中的消氮细菌及沉淀细菌对水体进行生物修复的作用及其效果，指出了存在的问题，为利用生物修复技术处理天然湖泊的富营养化提供了参考数据．     

难选金矿细菌预处理技术理论与实践

论述了预处理难选金矿细菌的种类、来源，浸出机理，浸出工艺及工业应用实践．归纳介绍了强化难选金矿细菌浸出的措施．     

Mapping of continuous floristic gradients in grasslands using hyperspectral imagery

Transitions between plant species assemblages are often continuous with the form of the transition dependent on the ‘slope’ of environmental gradients and on the style of self-organization in vegetation. Image segmentation can present misleading or even erroneous results if applied to continuous spatial changes in vegetation. Even methods that allow for multiple-class memberships of pixels presuppose the existence of ideal types of species assemblages that constitute mixtures—an assumption that does not fit the case of continua where any section of a gradient is as ‘pure’ as any other section like in modulations of grassland species composition.Thus, we attempted to spatially model floristic gradients in Bavarian meadows by extrapolating axes of an unconstrained ordination of species data. The models were based on high-resolution hyperspectral airborne imagery. We further modelled the distribution of plant functional response types (Ellenberg indicator values) and the cover values of selected species. The models were made with partial least squares (PLS) regression analyses. The realistic utility of the regression models was evaluated by full leave-one-out cross-validation.The modelled floristic gradients showed a considerable agreement with ground-based observations of floristic gradients (R²=0.71 and 0.66 for the first two axes of ordination). Apart from mapping the most important continuous floristic differences, we mapped gradients in the appearance of plant functional response groups as represented by averaged Ellenberg indicator values for soil pH (R²=0.76), water supply (R²=0.66) and nutrient supply (R²=0.75), while models for the cover of single species were weak.Compared to many other vegetation attributes, plant species composition is difficult to detect with remote sensing techniques. This is partly caused by a lack of compatibility between methods of vegetation ecology and remote sensing. We believe that the present study has the potential to increase compatibility as neither spectral nor vegetation information gets lost by a classifying step.     

番茄灰霉病拮抗细菌 R26抗菌物质产生条件的研究

拮抗细菌R26菌株的代谢产物对番茄灰霉病菌等多种植物病原真菌有较好的抑制作用。本试验研究结果表明，在含麦芽糖20g，牛肉浸膏8g，酵母浸膏5g的1000mL液体培养基中，最有利于其抗菌物质的产生；当温度为32℃，pH值为7，在250mL三角瓶中装20mL液体培养基，接种量为30％(v／v)时，R26菌株产生的抗菌物质抑菌活性最高。培养液中抗菌物质活性随着培养时间的延长而增加。培养36h达到最高。     

Whole soybean as probiotic lactic acid bacteria carrier food in solid-state fermentation

For the purpose of preparing lactic acid bacteria (LAB) carrier food, the solid-state fermentation of whole soybean was performed using Bifidobacterium animalis 937, Lactobacillus casei Zhang and Lactobacillus plantarum P-8 mixed with Bacillus subtilis natto, respectively. The physicochemical properties, the amino nitrogen content and peptide molecular weight distribution of the fermented whole soybean products were examined during this process. After 48 h of fermentation, the viable counts of the three samples were 1.41 × 10⁸ CFU/g (B. animalis 937), 1.74 × 10¹⁰ CFU/g (L. casei Zhang) and 2.19 × 10¹⁰ CFU/g (L. plantarum P-8), with the pH declined rapidly from 6.32 to 5.78, 5.60 and 5.44 at the early stage of the fermentation and increased to 6.71, 6.47 and 6.60 at the later stage of the fermentation. The fermentation caused a sharply increase in the content of the free amino nitrogen from 99.7 μmol/g to 301.9 μmol/g, 390.1 μmol/g and 529.1 μmol/g in the solid fermented soybean products, due to the multiplication of microorganism and the effect of enzyme system. Furthermore, the levels of soybean peptide with molecular weight less than 1000 Da increased 30.7%, 71.2% and 81.3% relative to that of the control group at 48 h. The result of the present work implied that whole soybean fermented by LAB can provide the different probiotics for the host, and there is potential to develope nutritious fermented soybean products.     

Cereal‐based fermented foods in developing countries: ancient foods for modern research

Cereal‐based fermented foods are major contributors to energy intake in developing countries (DC). Their microbiota is dominated by lactic acid bacteria and has been extensively investigated. Diversity studies have been facilitated by molecular methods enabling genotyping of isolates; the rapid development of ‘omics’ approaches should facilitate more comprehensive studies to describe the relation between microbial diversity, cell physiology and product characteristics. Also, the link between the food microbiota and health benefits, in particular in nutrition, should be investigated. There is a need to encourage researches in the field of DC cereal‐based foods in direction of more mechanistic approaches.     

Characterization and Technological Properties of Lactic Acid Bacteria Isolated from Traditional Argentinean Goat’s Milk Products

A total of 286 lactic acid bacteria isolated from goat’s dairy products in northwest of Argentina were characterized. Lactobacilli (38%) and cocci (62%) were identified according to morphological, physiological, and relevant technological properties. L. plantarum (14%) and Enterococcus (34%) were the predominant species. S. thermophilus, Pediococcus and L. plantarum were the highest acid producers. Eight strains of L. fermentum produced bacteriocins or metabolites similar to bacteriocins. The API-ZYM test was applied to 39 isolates. Eight strains were selected from their both technological properties and enzymatic activities for use as starter or adjunct culture in the manufacture of artisanal goat cheeses.     

Identification and antibiotic resistance of Lactobacilli isolated from raw cow’s milk of Oujda City (Morocco)

In this study, a Lactobacillus strain was isolated from raw cow milk. It was tentatively identified at the species level according to its carbohydrate fermentation profile and phenotype characteristics as Lactobacillus paracasei KSNM. The susceptibility of the identified Lactobacillus to 23 antibiotics was performed using the disc diffusion testing method. Inhibition zone diameters were measured and expressed in terms of sensitive, intermediate or resistant. KSNM strain was sensitive toward; amoxicillin, ampicillin, amoxyclav (amoxicillin + clavulanic acid), tetracycline, macrolides, sulfamides/trimethoprim, and rifampicin. But, it expressed intermediate sensitivity toward; cefamandole, cefaclor, and cephalothin. However, it was resistant to penicillin G, aminoglycosides, quinolones, ciprofloxacin, lincomycin, nitroxolin, and a large number of cephalosporins, which included cefoxitin, cefotaxime, and ceftriaxone.