盐度,一个关键因素,直接或间接地影响微生物群落结构和多样性。盐度水平的变化充当影响关键微生物物种转化的环境过滤器。本研究调查了高盐度胁迫下地下水中土著微生物区系与外部有机污染物的适应性特征。以西北地区高矿化度的浅层地下水为研究区,并选取6个有代表性的采样点,探讨地下水水化学参数和微生物区系的响应,以及确定土著微生物区系对联合污染的耐受机制。结果表明,在受有机污染物污染的高盐度地下水中发现的优势属即使在具有挑战性的高盐度条件下也具有降解此类污染物的显着能力。包括Halomonas,假单胞菌,硫杆菌,鞘氨醇单胞菌,Lutibacter,水细菌,硫微螺旋体,Aequorivita,等。水化学因素,包括总溶解固体(TDS),硫化物,亚硝酸盐,硝酸盐,氧化还原电位(ORP),NH3-N,Na,Fe,苯系物,酚类物质,和卤代烃,对微生物区系有显著影响。地下水中高浓度的硫酸盐和硫化物会对微生物区系产生双重影响。一方面,这些化合物可以抑制微生物的生长和代谢。另一方面,它们还可以在有机污染物的微生物降解过程中用作有效的电子供体/受体。微生物通过一系列耐受机制对高盐度和有机污染物的抑制作用表现出韧性。例如加强细胞外膜屏障,增强相关酶的合成,启动新的生化反应,提高细胞自我修复能力,通过迁移来应对不利的环境条件,并增强有机污染物微生物代谢的S循环。
Salinity, a critical factor, could directly or indirectly affect the microbial community structure and diversity. Changes in salinity levels act as environmental filters that influence the transformation of key microbial species. This study investigates the adaptive characteristics of indigenous microflora in groundwater in relation to external organic pollutants under high salinity stress. A highly mineralized shallow groundwater in Northwest China was conducted as the study area, and six representative sampling points were chosen to explore the response of groundwater hydrochemical parameters and microflora, as well as to identify the tolerance mechanisms of indigenous microflora to combined pollution. The results revealed that the dominant genera found in high salinity groundwater contaminated with organic pollutants possess the remarkable ability to degrade such pollutants even under challenging high salinity conditions, including Halomonas, Pseudomonas, Halothiobacillus, Sphingomonas, Lutibacter, Aquabacterium, Thiomicrospira, Aequorivita, etc. The hydrochemical factors, including total dissolved solids (TDS), sulfide, nitrite, nitrate, oxidation reduction potential (ORP), NH3-N, Na, Fe, benzene series, phenols, and halogenated hydrocarbons, demonstrated a significant influence on microflora. High levels of sulphate and sulfide in groundwater can exhibit dual effects on microflora. On one hand, these compounds can inhibit the growth and metabolism of microorganisms. On the other hand, they can also serve as effective electron donors/receptors during the microbial degradation of organic pollutants. Microorganisms exhibit resilience to the inhibitory effects of high salinity and organic pollutants via a series of tolerance mechanisms, such as strengthening the extracellular membrane barrier, enhancing the synthesis of relevant enzymes, initiating novel biochemical reactions, improving cellular self-healing capabilities, responding to unfavorable environmental conditions by migration, and enhancing the S cycle for the microbial metabolism of organic pollutants.