ENVIRONMENTAL GEOCHEMISTRY AND HEALTH
·
2017
·Vol. 40
·期 2
·763-776
·
IF 2.616
Wang Lanjun,Wang Jinhua,Zhu Lusheng,Wang Jun
The production of commercial livestock and poultry often involves using with antibiotics and feed additives, such as oxytetracycline (OTC) and copper (Cu). These are often excreted into the soil by animal feces; hence, combined pollutants may contaminate the soil. To evaluate single and combined toxic effects of OTC and Cu on the soil ecology, changes in quantities of bacteria, fungi, and actinomycetes in the soil were studied over a 28-d incubation period by a plate count method, microbes numbers counted on days 7, 14, 21, and 28. Abundances of ammonia monooxygenase ( amoA ) gene expression by ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) in soil samples also were tested by real-time polymerase chain reactions (RT-PCRs) on day 21. The results revealed that the numbers of bacteria, fungi and actinomycetes and amoA genes copies of AOA and AOB were reduced seriously by exposure to Cu (1.60 mmol/kg). Similarly, the combined pollution treatments (mole ratios of OTC: Cu was 1:2, 1:8, and 1:32) also had inhibitory effect on bacteria, fungi, and actinomycetes numbers and amoA gene copies of AOA and AOB; the inhibitory rate was on obvious growth trend with the increasing mole ratios. Effects from single OTC pollution were found on bacteria (days 7 and 14), fungi (days 7, 14, 21, and 28), and AOA- amoA gene copies (day 21), with promotion at a low concentration (0.05 mmol/kg) and suppression at higher concentrations (0.2 and 0.8 mmol/kg). Also, numbers of bacteria, fungi, and actinomycetes decreased with longer culture times. Combining OTC and Cu led to a higher inhibition of soil microbes than when either chemical was used alone. However, there was no significant relationship between single and combined toxic chemicals because of their complicated interactions, either antagonistic or synergistic. The results also indicated the sensitivity of bacteria, fungi, actinomycetes on toxic chemicals existed difference and that the AOA were more tolerant than the AOB to these chemicals.
研究领域:
环境科学
·
微生物学
·
土壤生态学
✓ 已验证
DOI
PubMed
高影响因子
Frontiers in Cellular and Infection Microbiology
·
2016
·
IF 5.218
Dong Yuhao,Liu Jin,Pang Maoda,Du Hechao,Wang Nannan,Awan Furqan,Lu Chengping,Liu Yongjie
The growth-stimulating effects of catecholamine stress hormones have been demonstrated in many pathogens. However, catecholamine-induced growth and its underlying mechanisms remain poorly understood in Aeromonas hydrophila. The present study sought to demonstrate that norepinephrine (NE), epinephrine (Epi), dopamine (Dopa), and L-dopa stimulate the growth of A. hydrophila in iron-restricted media containing serum. NE exhibited the strongest growth stimulation, which could be blocked by adrenergic antagonists. Furthermore, it was demonstrated that NE could sequester iron from transferrin, thereby providing a more accessible iron source for utilization by A. hydrophila. The deletion of the amoA gene associated with amonabactin synthesis revealed that the amonabactin siderophore is not required for NE-stimulated growth. However, the deletion of the TonB2 energy transduction system resulted in the loss of growth promotion by NE, indicating that a specific TonB-dependent outer membrane receptor might be involved in the transport of iron from transferrin. Collectively, our data show that catecholamine sensing promotes the growth of A. hydrophila in a manner that is dependent on the TonB2 energy transduction system.
研究领域:
微生物学
·
分子生物学
·
传染病学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2021
·
IF 6.291
Rui Tao,Hanjie Zhang,Xiuping Gu,Baowei Hu,Jun Li,Guixin Chu
Phthalic acid esters (PAEs) pollution has become an increasing issue worldwide, but little is known about its effects on ammonia-oxidizers and nitrous oxide (N 2 O) in the soil environment. Here, a 50-day soil microcosm experiment was conducted using low and high doses bis (2-Ethylhexyl) phthalate (DEHP) to estimate the effect of DEHP exposure on soil N 2 O emissions and the nitrifying community in calcareous soil. The results showed that DEHP exposure at 10 and 100 mg kg -1 doses significantly reduced N 2 O by 67.5% and 73.6%, respectively, relative to the DEHP absent treatment. The microbial biomass carbon and nitrogen (MBC and MBN) were consistently and significantly decreased with DEHP exposure at 5, 22, and 50 days after incubation, especially with high-dose. The bipartite association networks showed that DEHP exposure changed the compositions of both ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) communities. Moreover, the AOA and AOB amoA gene abundances were significantly decreased by DEHP addition to the soil ( P < 0.05). Random forest modeling showed that the AOB Shannon index and pH were the most important biotic and abiotic factors affecting N 2 O emissions in the soil with DEHP exposure, respectively. Partial least squares path modeling (PLS-PM) demonstrated that the reduction of N 2 O emissions due to DEHP exposure was mainly ascribed to the changes of the AOB community. The results from this study highlight the toxicity of DEHP on the ammonia oxidizers, and its mitigating effect on N 2 O emissions in the soil where ammonia-oxidation is largely driven by AOB.
研究领域:
环境科学
·
土壤微生物学
·
生态毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）