再生水灌溉对草坪根际可培养细菌组成影响

【目的】为了了解再生水灌溉对草坪根际可培养细菌群落组成的影响,【方法】采用稀释平板法,对北京市陶然亭公园内再生水灌区及其对照自来水灌区草坪根际细菌进行了分离,并对其16S rDNA序列进行了分析。【结果】16S rDNA序列分析表明自来水样品分离得到的菌落分属于15个属的20个种,而再生水样品分离得到的菌落分属于18个属的24个种。自来水和再生水灌区草坪根际细菌主要包括变形菌门α亚群(Alphaproteobacteria,分别为9.7%和13.4%)、变形菌门β亚群(Betaproteobacteria,分别为8.1%和12.3%)、变形菌门γ亚群(Gammaproteobacteria,分别为17.9%和42.0%)、拟杆菌门(Bacteroidetes,分别为13.0%和2.9%)、厚壁菌门(Firmicutes,分别为23.6%和10.1%)和放线菌门(Actinobacteria,分别为27.6%和19.6%)其中,芽孢杆菌属(Bacillus sp.)是自来水灌区草坪根际优势菌属(23.6%),而不动杆菌属(Acinetobacter sp.)是再生水灌区根际优势菌属(17.4%)。从不同类群优势菌属看,除变形菌门γ亚群受再生水影响优势菌属在两灌区表现出一定的差异外,其余各亚群优势菌属均未受再生水影响,其中,不动杆菌属是再生水灌区变形菌门γ亚群的优势菌属(41.3%),肠杆菌属(Enterobacter sp.)是自来水灌区变形菌门γ亚群的优势菌属(45.4%)。【结论】这表明,再生水灌溉未改变细菌群落组成类型,但改变了不同类型多度分布状况。具体表现为优势种多度值增加及部分非优势种有无。再生水灌区特有机会性致病菌、植物致病菌和重金属耐性细菌的出现表明再生水灌溉中病原微生物及重金属的控制工作还有待于进一步严格。

Effects of recycled water irrigation on bacterial community compositions in lawn soil

Abstract: Objective] In order to obtain the information about how irrigations with recycled water affecting the cultivable microbial population of the rhizosphere of turfgrasses, Methods] We isolated strains from two irrigated areas with recycled water (RW) and drinking water (DW) in Taoranting Park in Beijing, China, by using diluting plate and counting method, and analyzing the 16S rDNA sequence of the isolates. Results] We obtained 20 and 25 strains with different morphological character of colonies from the area irrigated with DW and area irrigated with RW, respectively. The sequence analysis of 16SrDNA showed that RW-irrigated system supported more complex communities of 18 genus and 24 species, whereas the DW-irrigated system only supported 15 genus and 20 species. Both samples had similar microbial population. There were 9.7% or 13.4% alphaproteobacteria, 8.1% or 12.3% betaproteobacteria, 17.9% or 42.0% gammaproteobacteria, 13.0% or 2.9% bacteroidetes, 23.6% or 10.1% firmicutes, and 27.6% or 19.6% actinobacteria at the rhizosphere of turfgrasses irrigated with DW or RW respectively. The dominant bacteria in DW area were the genera Bacillus whereas that of RW area was the genera Acinetobacter. Other than the gammaproteobacteria, the dominant genera in other groups of two areas were similar. Conclusion] The result showed that the bacterial community composition of rhizosphere samples did not change, but the distribution of different types of bacteria does change after irrigation by reclaimed water, which were determined by the abundance increasing of the dominant species and the appearance or disappearance of non-dominant species. Finally, it is important that the control of the pathogen and metal should be enforced when using RW for irrigation.