[Phylogenetic diversity of airborne microbes in Qingdao downtown in autumn].

To determine the community structure of airborne microbes in Qingdao downtown in autumn, the airborne bacteria and fungi were collected by the KC-6120 air sampler and analyzed using the 16S/18S rDNA gene clone library method. Phylogenetic analysis of airborne bacteria showed that they belonged to six major phylogenetic groups: Proteobacteria (78. 8%), Firmicutes (14.6%), Actinobacteria (4.0%), Planctomycetes (1.3%), Cyanobacteria (0.7%), and Deinococcus-Thermus (0.7%). The dominant genera of airborne bacteria included Acinetobacter (39.7%), Staphylococcus (11.3%), Sphingomonas (8.6%), Paracoccus (6.0%) and Massilia (5.3%). The main types of airborne fungi were Ascomycota (97.5%) and Basidiomycota (2.5%). Dominant genera of airborne fungi included Pyrenophora (76.5%), Xylaria (13.6%) and Exophiala (2.5%). The pathogens or conditioned pathogens, such as Acinetobacter, Staphylococcus, or Sphingomonas were detected in the airborne bacteria, whereas certain kinds of fungi, such as P. graminea, X. hypoxylon and Zasmidium angulare that could cause a variety of crop diseases were also detected.

[Carbon sources metabolic characteristics of airborne microbial communities in constructed wetlands].

Using BIOLOG-GN plates, this article describes the carbon sources metabolic characteristics of airborne microbial communities in a free surface-flow constructed wetland in different seasons and clarify the correlation between airborne microbial metabolic functions and environmental factors. The average well color development (AWCD), carbon metabolic profiles and McIntosh values of airborne microbial communities in different seasons were quite different. Analysis of the variations showed that AWCD in spring and summer differed significantly from that in autumn and winter (P < 0.01). In the same season, the degree of utilization of different types of carbon by airborne microbes was different. Summer had a significant difference from other seasons (P < 0.05). Dominant communities of airborne microbes in four seasons were carboxylic acids metabolic community, carbohydrates metabolic community, polymers metabolic community and carboxylic acids metabolic community respectively. Principal component analysis showed that the carbon metabolic characteristics of airborne microbial community in autumn were similar to those in winter but different from those in spring and summer. The characteristics of carbon metabolism revealed differences between summer and spring, autumn, or winter. These differences were mainly caused by amines or amides while the differences between spring and autumn or winter were mainly caused by carboxylic acids. Environmental factors, including changes in wind speed, temperature, and humidity acted to influence the carbon sources metabolic properties of airborne microbial community. The dominant environmental factors that acted to influence the carbon sources metabolic properties of airborne microbial community varied between different seasons.

[Microbial community of municipal discharges in a sewage treatment plant].

There are numerous microorganisms, especial pathogens, in the discharges. Those microorganisms are discharged into the river and sea through sewage outfalls, which results in possible health risks to coastal populations. And more attention should be paid to municipal discharges in developing countries. This study investigated the microbial community in the discharges by constructing 16S rDNA clones library and using the PCR-RFLP technology. Phylogenetic analysis of bacteria in municipal discharges showed that there were 59 species, which were divided into 11 classes. Proteobacteria accounted for 85% of all the bacteria, of which ß-Proteobacteria and γ- Proteobacteria were the dominant classes. Bacteria in the waste water treating process had important influence on microbial community in municipal discharges, therefore, municipal sewage plant should choose the process according to the characteristics and purifying capacity of the receiving water body. Legionella spp. accounted for approximately 10% , the Legionnaires' disease resulted from which might be of top risk for the residents in the surrounding of the municipal discharges outfall and receiving water. Dechloromonas aromatica could make use of chlorite ( CIO - ) , which led to its survival from chlorine disinfection, and it alerted us that several disinfection methods should be used together to ensure the bacterial safety of municipal discharges. Coliform group and other pathogenic bacteria, such as Salmonella spp. , Shigella spp. , Escherichia coli, Vibrio cholerae, Staphylococcus aureus, Arcobacter spp. were not detected in this study, and it indicated that we should do more work and use more methods to investigate the perniciousness of discharges.

[Effect of different primers on microbial community of activated sludge].

The aim of this study was to investigate the effect of different primers in PCR-DGGE and PCR-RFLP on the analysis of microbial community in activated sludge. 8 pairs of primers were chosen to amplify the variable region of 16S rDNA for PCR-DGGE analysis, while 11 pairs of primers were used to amplify the total length of 16S rDNA for PCR-RFLP analysis. The effect of different primers on the analysis of microbial community in activated sludge was determined by electrophoresis analysis of the PCR products. The microbial community of the activated sludge was different when different primers were used. For PCR-DGGE analysis, the primers B341F/B534R had good amplification results and the bands were excessive; while for PCR-RFLP, the primers 27f/8f and 1500R had good amplification results and the bands digested by the two enzymes had the highest diversity. The primers B341F/B534R and 27f/8f/ 1500R were relatively good for PCR-DGGE and PCR-RFLP, respectively, in the analysis of microbial community in activated sludge.