[Composition and Environmental Adaptation of Microbial Community in Shibahe Copper Tailing in Zhongtiao Mountain in Shanxi].

In order to reveal the effects of heavy metal pollution on microbial community compositions and microbial community diversity in tailing area,we conducted an experiment by examining the microbial community in tailing water,sediments and tailing sand in Shibahe copper tailing in Zhongtiao Mountain.Differences in microbial community compositions in different habitats and their relationships with environmental parameters were analyzed.The results showed that the richness and diversity of microbial community were the largest in tailing sand,but the lowest in tailing water.Microbial community compositions were similar between tailing water and sediments.There were significant positive correlations between the relative abundance of the dominant family (Sphingomonadaceae) and contents of heavy metals (Cd,Cu,Mn,Ni,Pb,Zn),while there were significant negative correlations between relative abundances of aulobacteraceae, Methylobacteriaceae, Nocardioidaceae, Microbacteriaceae, Micrococcaceae, Streptococcaceae and Paenibacillaceae and heavy metal contents.It showed that most of the bacteria were inhibited by heavy metals,but Sphingomonadaceae had a higher tolerance to heavy metals which may indicate that it has a potential for remediation of heavy metal contamination.

Clinical comparison of Fuji VII and a resin sealant in children at high and low risk of caries.

The purpose was to compare the retention and caries preventive effect of Fuji VII and a resin-based sealant in children at high risk (HR) and low risk (LR) of caries. Fifty-seven schoolchildren (150 teeth) with completely erupted bilateral permanent first molars were included. The study was a split-mouth, randomized trial. Sealant retention and caries were evaluated after 6 months, 1 year and 2 years. After 2 years, there was no statistically significant difference in the incidence of caries between Fuji VII and Concise in the HR and LR groups. With Concise, LR children were less likely to have dental caries than HR. With Fuji VII, there was no difference in caries incidence between LR and HR. Retention of Concise was superior to that of Fuji VII. Our results suggest that Fuji VII and Concise sealants had similar caries preventive effects in children at high and low risk of caries.

2,4-Dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA) and 6-methoxy-benzoxazolin-2-one (MBOA) levels in the wheat rhizosphere and their effect on the soil microbial community structure.

Despite increasing knowledge of 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA) and 6-methoxy-benzoxazolin-2-one (MBOA) as allelochemicals involved in the defense of wheat against pests, relatively little is known about their levels in the rhizosphere and interactions with the soil microbial community. This study quantified DIMBOA and MBOA in the wheat rhizosphere and analyzed the soil microbial community structure. MBOA rather than DIMBAO was found in the wheat rhizosphere, and its concentration varied with cultivars, plant densities, and growth conditions. Wheat could detect the presence of competing weeds and respond by increased MBOA in the rhizosphere. There was a linear positive relationship between the MBOA level in the wheat rhizosphere and soil fungi/bacteria. When DIMBOA was applied to soil, yielding MBOA increased soil fungi. There were different phospholipid fatty acid (PLFA) patterns in soil incubated with DIMBOA and MBOA. These results suggested that DIMBOA and MBOA could affect the soil microbial community structure to their advantage through the change in fungi populations.