Determination of the archaeal and bacterial communities in two-phase and single-stage anaerobic systems by 454 pyrosequencing

2-Phase anaerobic digestion (AD), where the acidogenic phase was operated at 2 day hydraulic retention time (HRT) and the methanogenic phase at 10 days HRT, had been evaluated to determine if it could provide higher organic reduction and methane production than the conventional single-stage AD (also operated at 12 days HRT). 454 pyrosequencing was performed to determine and compare the microbial communities. The acidogenic reactor of the 2-phase system yielded a unique bacterial community of the lowest richness and diversity, while bacterial profiles of the methanogenic reactor closely followed the single-stage reactor. All reactors were predominated by hydrogenotrophic methanogens, mainly Methanolinea. Unusually, the acidogenic reactor contributed up to 24% of total methane production in the 2-phase system. This could be explained by the presence of Methanosarcina and Methanobrevibacter, and their activities could also help regulate reactor alkalinity during high loading conditions through carbon dioxide production. The enrichment of hydrolytic and acidogenic Porphyromonadaceae, Prevotellaceae, Ruminococcaceae and unclassified Bacteroidetes in the acidogenic reactor would have contributed to the improved sludge volatile solids degradation, and ultimately the overall 2-phase system''s performance. Syntrophic acetogenic microorganisms were absent in the acidogenic reactor but present in the downstream methanogenic reactor, indicating the retention of various metabolic pathways also found in a single-stage system. The determination of key microorganisms further expands our understanding of the complex biological functions in AD process.     

Molecular approaches for the detection and monitoring of microbial communities in bioaerosols: A review

Bioaerosols significantly affect atmospheric processes while they undergo long-range vertical and horizontal transport and influence atmospheric chemistry and physics and climate change. Accumulating evidence suggests that exposure to bioaerosols may cause adverse health effects, including severe disease. Studies of bioaerosols have primarily focused on their chemical composition and largely neglected their biological composition and the negative effects of biological composition on ecosystems and human health. Here, current molecular methods for the identification, quantification, and distribution of bioaerosol agents are reviewed. Modern developments in environmental microbiology technology would be favorable in elucidation of microbial temporal and spatial distribution in the atmosphere at high resolution. In addition, these provide additional supports for growing evidence that microbial diversity or composition in the bioaerosol is an indispensable environmental aspect linking with public health.     

Molecular characterization of methanogenic microbial communities for degrading various types of polycyclic aromatic hydrocarbon

Knowledge on methanogenic microbial communities associated with the degradation of polycyclic aromatic hydrocarbons (PAHs) is crucial to developing strategies for PAHs bioremediation. In this study, the linkage between the type of PAHs and microbial community structure was fully investigated through 16S rRNA gene sequencing on four PAH-degrading cultures. Putative degradation products were also detected. Our results indicated that naphthalene (Nap)/2-methylnaphthalene (2-Nap), phenanthrene (Phe) and anthracene (Ant) sculpted different microbial communities. Among them, Nap and 2-Nap selected for similar degrading bacteria (i.e., Alicycliphilus and Thauera) and methanogens (Methanomethylovorans and Methanobacterium). Nap and 2-Nap were probably activated via carboxylation, producing 2-naphthoic acid. In contrast, Phe and Ant shaped different bacterial and archaeal communities, with Arcobacter and Acinetobacter being Phe-degraders and Thiobacillus Ant-degrader. Methanogenic archaea Methanobacterium and Methanomethylovorans predominated Phe-degrading and Ant-degrading culture, respectively. These findings can improve our understanding of natural PAHs attenuation and provide some guidance for PAHs bioremediation in methanogenic environment.     

Reduction and characterization of bioaerosols in a wastewater treatment station via ventilation

Bioaerosols from wastewater treatment processes are a significant subgroup of atmospheric aerosols. In the present study,airborne microorganisms generated from a wastewater treatment station(WWTS) that uses an oxidation ditch process were diminished by ventilation.Conventional sampling and detection methods combined with cloning/sequencing techniques were applied to determine the groups,concentrations,size distributions,and species diversity of airborne microorganisms before and after ventilation. There were 3021 ± 537 CFU/m3 of airborne bacteria and 926 ± 132 CFU/m3 of airborne fungi present in the WWTS bioaerosol.Results showed that the ventilation reduced airborne microorganisms significantly compared to the air in the WWTS. Over 60% of airborne bacteria and airborne fungi could be reduced after4 hr of air exchange. The highest removal(92.1% for airborne bacteria and 89.1% for fungi) was achieved for 0.65–1.1 μm sized particles. The bioaerosol particles over 4.7 μm were also reduced effectively. Large particles tended to be lost by gravitational settling and small particles were generally carried away,which led to the relatively easy reduction of bioaerosol particles0.65–1.1 μm and over 4.7 μm in size. An obvious variation occurred in the structure of the bacterial communities when ventilation was applied to control the airborne microorganisms in enclosed spaces.     

酸性矿山废水对稻田土壤微生物菌群结构的影响

为探究酸性矿山废水(AMD)对稻田土壤微生物群落结构的影响,通过取自矿区受AMD污染和未受污染的稻田土壤进行微宇宙灌溉模拟实验,研究了AMD污染过程中土壤理化性质和微生物群落的变化,同时建立环境条件变化引起土壤微生物群落结构改变的相关性关系.结果表明,受AMD污染的土壤中SO_4~(2-)、Cd、Zn含量显著上升,土壤酸化且土壤中细菌群落的多样性下降;而恢复清洁水灌溉可提高土壤细菌群落的多样性,有利于修复AMD的污染.采用高通量测序技术分析了不同处理稻田土壤中微生物群落在门和属分类水平上的相对丰度分布变化,冗余分析(RDA)表明,土壤pH和重金属(Pb、Cu)含量是影响稻田土壤微生物群落结构的主要环境因子.研究结果不仅有助于进一步揭示AMD污染、土壤因子与土壤微生物群落的相互关系,同时可为恢复AMD污染农业土壤提供理论依据.     

Quantification of multi-antibiotic resistant opportunistic pathogenic bacteria in bioaerosols in and around a pharmaceutical wastewater treatment plant

Pharmaceutical wastewater treatment plants(WWTPs) are thought to be a "seedbed" and reservoirs for multi-antibiotic resistant pathogenic bacteria which can be transmitted to the air environment through aeration. We quantified airborne multi-antibiotic resistance in a full-scale plant to treat antibiotics-producing wastewater by collecting bioaerosol samples from December2014 to July 2015. Gram-negative opportunistic pathogenic bacteria(GNOPB) were isolated, and antibiotic susceptibility tests against 18 commonly used antibiotics, including 11 β-lactam antibiotics, 3 aminoglycosides, 2 fluoroquinolones, 1 furan and 1 sulfonamide, were conducted.More than 45% of airborne bacteria isolated from the pharmaceutical WWTP were resistant to three or more antibiotics, and some opportunistic pathogenic strains were resistant to 16 antibiotics, whereas 45.3% and 50.3% of the strains isolated from residential community and municipal WWTP showed resistance to three or more antibiotics. The calculation of the multiple antibiotic resistance(MAR) index demonstrated that the air environment in the pharmaceutical WWTP was highly impacted by antibiotic resistance, while the residential community and municipal WWTP was less impacted by antibiotic resistance. In addition, we determined that the dominant genera of opportunistic pathogenic bacteria isolated from all bioaerosol samples were Acinetobacter, Alcaligenes, Citrobacter, Enterobacter, Escherichia, Klebsiella, Pantoea, Pseudomonas and Sphingomonas. Collectively, these results indicate the proliferations and spread of antibiotic resistance through bioaerosols in WWTP treating cephalosporin-producing wastewater, which imposed a potential health risk for the staff and residents in the neighborhood, calling for administrative measures to minimize the air-transmission hazard.     

Identification of potential electrotrophic microbial community in paddy soils by enrichment of microbial electrolysis cell biocathodes

Electrotrophs are microbes that can receive electrons directly from cathode in a microbial electrolysis cell(MEC).They not only participate in organic biosynthesis,but also be crucial in cathode-based bioremediation.However,little is known about the electrotrophic community in paddy soils.Here,the putative electrotrophs were enriched by cathodes of MECs constructed from five paddy soils with various properties using bicarbonate as an electron acceptor,and identified by 16 S rRNA-gene based Illum...     

Biodegradation of 2-ethylhexyl-4-methoxycinnamate in river sediments and its impact on microbial communities

Numerous studies have evaluated the toxicity and endocrine disrupting properties of organic UV filters for aquatic organisms, but little is known about their biodegradation in river sediments and their impact on microorganisms. We have set up the sterile and microbiological systems in the laboratory, adding 2-ethylhexyl-4-methoxycinnamate (EHMC), one of organic UV filters included in the list of high yield chemicals, at concentrations of 2, 20 and 200 μg/L, and characterized the microbial community composition and diversity in sediments. Monitoring of EHMC degradation within 30 days revealed that the half-life in the microbial system (3.49 days) was much shorter than that in the sterile system (7.55 days). Two potential degradation products, 4-mercaptobenzoic acid and 3-methoxyphenol were identified in the microbial system. Furthermore, high-throughput 16s and 18s rRNA gene sequencing showed that Proteobacteria dominated the sediment bacterial assemblages followed by Chloroflexi, Acidobacteria, Bacteroidetes and Nitrospirae; Eukaryota_uncultured fungus dominated the sediment fungal assemblages. Correlation analysis demonstrated that two bacterium genera (Anaerolineaceae_uncultured and Burkholderiaceae_uncultured) were significantly correlated with the biodegradation of EHMC. These results illustrate the biodegradability of EHMC in river sediments and its potential impact on microbial communities, which can provide useful information for eliminating the pollution of organic UV filters in natural river systems and assessing their potential ecological risks.     

安徽某铁矿酸性矿山废水夏季和秋季微生物群落结构特征

分别采集了夏秋两季安徽某铁矿的酸性矿山废水样品,分析其物理化学参数,并利用分子生物学方法研究了该酸性矿山废水中微生物群落结构随时间和空间的变化规律.结果表明:该矿山废水酸性极强,夏季所采样品pH在2.80左右,且阴阳离子含量很高,Al~(3+)为1108~1138mg·L~(-1),SO_4~(2-)则高达19.80~23.79 g·L~(-1).秋季样品p H没有明显变化,但由于两次采样期间的大量降水,样品中各离子含量明显低于夏季.值得注意的是,该极端酸性的矿山废水中叶绿素a含量较高,夏季达63.8~94.2μg·L~(-1),秋季则降至16.6~32.7μg·L~(-1).无论是在夏季还是秋季,Alphaproteobacteria在绝大多数位点的细菌群落中占据着优势地位.化能异养菌Acidiphilium是最主要的细菌菌属,它在夏季和秋季各位点群落中所占比例都达20%左右,这应该与其丰富的代谢方式有关.对于真核微生物群落,夏季主要为尖毛虫和小球藻,秋季主要为棕鞭藻和小球藻.小球藻是该酸性生态系统主要的生产者,尖毛虫和棕鞭藻则扮演着顶级消费者的角色.该酸性废水应处于酸水形成末期,所以细菌群落中化能异养菌占据着优势地位,化能自养菌比例较少.由于温度等理化性质的不同,微生物群落结构随时间和空间发生了一定变化,其中以真核微生物群落结构变化最为显著.     

基于454和Illumina高通量测序平台对长江口邻近海域沉积物微生物群落的比较分析

作为第二代测序技术的主要平台, 454和Illumina测序方法在微生物核酸分析方面有着广泛应用。本研究以16S rRNA基因为标靶, 分别采用454和Illumina测序技术对长江口邻近海域表层沉积物中的微生物DNA进行分析, 通过对序列长度、微生物群落多样性及组成进行比较, 分析两种方法在沉积物微生物群落结构研究方面的适用性。结果表明, Illumina测序获得的序列数和OTU数要多于454, 其中获得的OTUs中以非优势菌群为主。Illumina与454相比能够检出更多微生物菌群, 且检测到的稀有菌群占有较大比例。综上可知, Illumina测序技术在分析微生物群落多样性及物种组成方面要优于454测序技术, 454的长序列优势并未能体现出来, 且454测序技术可能低估了微生物组成及其多样性。     

焦作煤矿区矿坑排水对地下水环境的影响

焦作矿区随着煤矿资源的开发,矿坑排水造成的环境地质问题日益突出,主要表现为区域地下水位下降及矿区水环境污染问题,已严重制约着焦作煤炭工业的发展。本文就煤矿开采引发的环境地质问题进行了剖析并提出了相应的防治对策。     

Alterations in microbial community during the remediation of a black-odorous stream by acclimated composite microorganisms

Microbial application is an efficient, economical, and ecofriendly method for remediating black-odorous rivers. In this study, the field treatment effect and microbial community changes were monitored during remediation by the acclimated complex microorganisms of a typical black-odorous stream. After the treatment, the total phosphorus and ammonia contents decreased by 74.0% and 76.3% and the concentrations of dissolved oxygen increased from 1.65 to 4.90 mg/L, indicating the effectiveness of the acclimated composite microorganisms. The proportion of Bacteroidetes decreased significantly by 48.1% and that of Firmicutes increased by 2.23% on average, and the microbial diversity index first increased and then tended to be uniform. Redundancy analysis demonstrated that the pH, dissolved oxygen, and oxidation-reduction potential together determined the composition of the microbial communities (p < 0.05). These findings showed that the acclimated composite microorganisms can effectively remediate the black odor.     

煤矿社区居民的资源开发态度及其影响因素分析

居民对资源开发的态度是资源开发管理的重要社会与公众基础。基于对煤矿社区居民的调研数据,实证分析了居民资源开发态度的特征及其影响因素差异。结果显示：煤矿社区居民对资源开发总体呈现比较反对的态度。居民社会人口属性方面,受教育水平越高其对资源开发态度的支持程度越高;女性比男性更支持煤矿开采。在社会文化层面,就业机会和社会个人利益正向、显著影响居民资源开发态度;煤矿开采对居民生活和健康的不利影响负向、显著影响居民资源开发态度。在经济交通层面,资源开发的配套设施建设正向、显著影响居民资源开发态度;土地破坏和粮食减产负向、显著影响居民资源开发态度。在生态环境层面,自然灾害和地质灾害发生情况以及水质和水量的下降情况负向、显著影响居民资源开发态度。建议未来应制定针对性政策,改善居民资源开发态度,并着眼于资源开发沟通机制的完善、居民参与资源开发规划的制定和外部管理制度建设能力的提升。     

Mixing regime shapes the community assembly process, microbial interaction and proliferation of cyanobacterial species Planktothrix in a stratified lake

Lake mixing influences aquatic chemical properties and microbial community composition,and thus, we hypothesized that it would alter microbial community assembly and interaction. To clarify this issue, we explored the community assembly processes and cooccurrence networks in four seasons at two depths(epilimnion and hypolimnion) in a mesotrophic and stratified lake(Chenghai Lake), which formed stratification in the summer and turnover in the winter. During the stratification period, the epilimni...     

Co-metabolic and biochar-promoted biodegradation of mixed PAHs by highly efficient microbial consortium QY1

Polycyclic aromatic hydrocarbons (PAHs), typical representatives of the persistent organic pollutants (POPs), have become ubiquitous in the environment. In this study, a novel microbial consortium QY1 that performed outstanding PAHs-degrading capacity has been enriched. The degradation characteristics of single and mixed PAHs treated with QY1 were studied, and the effect of biochar on biodegradation of mixed PAHs and the potential of biochar in PAHs-heavy metal combined pollution bioremediation were also investigated. Results showed that, in single substrate system, QY1 degraded 94.5% of 500 mg/L phenanthrene (PHE) and 17.8% of 10 mg/L pyrene (PYR) after 7 days, while in PHE-PYR mixture system, the biodegradation efficiencies of PHE (500 mg/L) and PYR (10 mg/L) reached 94.0% and 96.2%, respectively, since PHE served as co-metabolic substrate to have significantly improved PYR biodegradation. Notably, with the cooperation of biochar, the biodegradations of PHE and PYR were greatly accelerated. Further, biochar could reduce the adverse impact of heavy metals (Cd²⁺, Cu²⁺, Cr₂O₇^2?) on PYR biodegradation remarkably. The sequencing analysis revealed that Methylobacterium, Burkholderia and Stenotrophomonas were the dominant genera of QY1 in almost all treatments, indicating that these genera might play key roles in PAHs biodegradation. Overall, this study provided new insights into the efficient bioremediation of PAHs-contaminated site.     

Revealing the anaerobic acclimation of microbial community in a membrane bioreactor for coking wastewater treatment by Illumina Miseq sequencing

The dynamic change of microbial community during sludge acclimation from aerobic to anaerobic in a MBR for coking wastewater treatment was revealed by Illumina Miseq sequencing in this study. The diversity of both Bacteria and Archaea showed an increase–decrease trajectory during acclimation, and exhibited the highest at the domestication interim. Ignavibacteria changed from a tiny minority(less than 1%) to the dominant bacterial group(54.0%) along with acclimation. The relative abundance of Betaproteobacteria kept relatively steady, as in this class some species increased coupled with some other species decreased during acclimation. The dominant Archaea shifted from Halobacteria in initial aerobic sludge to Methanobacteria in the acclimated anaerobic sludge. The dominant bacterial and archaeal groups in different acclimation stages were indigenous microorganisms in the initial sludge, though some of them were very rare. This study supported that the species in"rare biosphere" might eventually become dominant in response to environmental change.     

Shifts in microbial community structure and diversity in a MBR combined with worm reactors treating synthetic wastewater

The chemical oxygen demand (COD) and NH₃-N removal, membrane fouling, sludge characteristics and microbial community structure in a membrane bioreactor (MBR) coupled with worm reactors (SSBWR) were evaluated for 210 days. The obtained results were compared to those from a conventional MBR (C-MBR) operated in parallel. The results indicated that the combined MBR (S-MBR) achieved higher COD and NH₃-N removal efficiency, slower increase in membrane fouling, better sludge settleability and higher activities of the related enzymes in the activated sludge. Denaturing gradient gel electrophoresis was used to analyze the microbial community structures in the C-MBR and the S-MBR. The microbial community structure in the S-MBR was more diverse than that in the C-MBR. Additionally, the slow-growing microbes such as Saprospiraceae, Actinomyces, Frankia, Clostridium, Comamonas, Pseudomonas, Dechloromonas and Flavobacterium were enriched in the S-MBR, further accounting for the sludge reduction, membrane fouling alleviation and wastewater treatment.     

采煤驱动下复杂井田含水层化学特征与水力联系辨识

通过分析复杂井田不同含水层的常规元素、微量元素、氘氧同位素与氚同位素的水化学特征来判断各含水层的水力联系,并分别建立了Piper识别图版、Durov识别图版、氘氧同位素识别图版,借此可以快速甄别矿井突水的来源.结果表明:研究区地下水主要为大气降水补给,第四系含水层与直罗组含水层存在显著联系,直罗组含水层与延安组存在有限的联系.利用各含水层不同岩性导致的水化学离子特征差异和氘氧同位素、氚同位素的示踪特性建立识别图版,可有助于快速识别补连塔矿区突水水源,并对不同含水层的突水事故提出针对性的解决措施.     

排水管道沉积物微生物群落及环境因子分析

选取北京市某区的排水管道沉积物进行取样,采用高通量测序手段分析,结果表明变形菌门、广古菌门、拟杆菌门、厚壁菌门是排水管道沉积物微生物中的优势门类;在纲水平上,δ-变形菌纲、甲烷微菌纲、梭菌纲、拟杆菌纲占相对优势;在属水平上,功能性微生物硫酸盐还原菌（SRB）和产甲烷古菌（MA）普遍存在于各处管道.在所选的6段管段中,管段S3、S4处MA的相对丰度分别为20.6%、40.8%,高于其他管段,厌氧产甲烷的潜能较大,有发生可燃气积累的风险;管段S5、S6处的SRB相对丰度分别为9.14%、8.19%,高于其他管段,硫酸盐还原为硫化物的潜能较大,存在管道腐蚀的风险.RDA分析表明污水的DO、水温、硫酸根、TN与管道沉积物中微生物群落存在相关性.     

排水管道沉积物微生物群落及环境因子分析

选取北京市某区的排水管道沉积物进行取样,采用高通量测序手段分析,结果表明变形菌门、广古菌门、拟杆菌门、厚壁菌门是排水管道沉积物微生物中的优势门类;在纲水平上,δ-变形菌纲、甲烷微菌纲、梭菌纲、拟杆菌纲占相对优势;在属水平上,功能性微生物硫酸盐还原菌（SRB）和产甲烷古菌（MA）普遍存在于各处管道.在所选的6段管段中,管段S3、S4处MA的相对丰度分别为20.6%、40.8%,高于其他管段,厌氧产甲烷的潜能较大,有发生可燃气积累的风险;管段S5、S6处的SRB相对丰度分别为9.14%、8.19%,高于其他管段,硫酸盐还原为硫化物的潜能较大,存在管道腐蚀的风险.RDA分析表明污水的DO、水温、硫酸根、TN与管道沉积物中微生物群落存在相关性.