土壤生态系统越来越受到多卤化咔唑(PHCZs)的污染,这引起了人们对它们对土壤微生物的影响的极大关注。3-溴咔唑(3-BCZ)和1,3,6,8-四溴咔唑(1,3,6,8-TBCZ)是两种典型的PHCZ,在土壤环境中具有较高的检出率。然而,对这两种PHCZs在土壤中的生态风险研究尚缺乏。在本研究中,暴露80天后,基于16SrDNA测序研究了3-BCZ和1,3,6,8-TBCZ的生态影响,ITS排序,基因(16SrDNA,ITS,amoA,nifH,narG和cbbL)丰度和土壤酶活性。结果表明,在3-BCZ和1,3,6,8-TBCZ暴露后,细菌16SrDNA基因丰度显着降低。在1,3,6,8-TBCZ(10mg/kg)暴露下,真菌ITS基因丰度显着降低。PHCZ促进了细菌和真菌群落丰度的改变。细菌鞘氨醇单胞菌,RB41和真菌被孢霉,黄参被确定为最主要的属。这两个PHCZ一致降低了鞘氨醇单胞菌的相对丰度,溶菌杆菌,Dokdonella,第80天的被孢霉和黄参等。这些梯形分类群与有机化合物的降解有关,碳代谢,和氮代谢,从而可能对土壤生态功能产生影响。使用原核分类群(FAPROTAX)和真菌功能协会(FUNGuild)的功能注释来估计细菌和真菌功能,分别。氮和碳代谢途径受3-BCZ和1,3,6,8-TBCZ的影响。好氧氨氧化的土壤氮相关功能降低,但甲醇氧化的土壤碳相关功能降低,发酵,在第80天,碳氢化合物的降解增加。3-BCZ和1,3,6,8-TBCZ对amoA丰度的影响,nifH,narg,cbbL基因呈阴性趋势。这些结果阐明了PHCZ的生态效应,并扩展了我们对PHCZ污染的生态系统中土壤微生物的结构和功能的了解。
Soil ecosystems are being more contaminated with polyhalogenated carbazoles (PHCZs), which raising much attention about their impact on soil microorganisms. 3-Bromocarbazole (3-BCZ) and 1,3,6,8-tetrabromocarbazole (1,3,6,8-TBCZ) are two typical PHCZs with high detection rates in the soil environment. However, ecological risk research on these two PHCZs in soil is still lacking. In the present study, after 80 days of exposure, the ecological influence of 3-BCZ and 1,3,6,8-TBCZ was investigated based on 16S rDNA sequencing, ITS sequencing, gene (16S rDNA, ITS, amoA, nifH, narG and cbbL) abundance and soil enzyme activity. The results showed that the bacterial 16S rDNA gene abundance significantly decreased under 3-BCZ and 1,3,6,8-TBCZ exposure after 80 days of incubation. The fungal ITS gene abundance significantly decreased under 1,3,6,8-TBCZ (10 mg/kg) exposure. PHCZs contributed to the alteration of bacteria and fungi community abundance. Bacteria Sphingomonas, RB41 and fungus Mortierella, Cercophora were identified as the most dominant genera. The two PHCZs consistently decreased the relative abundance of Sphingomonas, Lysobacter, Dokdonella, Mortierella and Cercophora etc at 80th day. These keystone taxa are related to the degradation of organic compounds, carbon metabolism, and nitrogen metabolism and may thus have influence on soil ecological functions. Bacterial and fungal functions were estimated using functional annotation of prokaryotic taxa (
FAPROTAX) and fungi functional guild (FUNGuild), respectively. The nitrogen and carbon metabolism pathway were affected by 3-BCZ and 1,3,6,8-TBCZ. The soil nitrogen-related functions of aerobic ammonia oxidation were decreased but the soil carbon-related functions of methanol oxidation, fermentation, and hydrocarbon degradation were increased at 80th day. The effects of 3-BCZ and 1,3,6,8-TBCZ on the abundances of the amoA, nifH, narG, and cbbL genes showed a negative trend. These results elucidate the ecological effects of PHCZs and extend our knowledge on the structure and function of soil microorganisms in PHCZ-contaminated ecosystems.