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1.
Environ Monit Assess ; 192(8): 539, 2020 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-32705349

RESUMO

Microbial communities occur in almost every habitat. To evaluate the homeostasis disruption of in situ microbiomes, dredged sediments from Guanabara Bay-Brazil (GB) were mixed with sediments from outside of the bay (D) in three different proportions (25%, 50%, and 75%) which we called GBD25, GBD50, and GBD75. Grain size, TOC, and metals-as indicators of complex contamination-dehydrogenase (DHA) and esterase enzymes (EST)-as indicators of microbial community availability-were determined. Microbial community composition was addressed by amplifying the 16S rRNA gene for DGGE analysis and sequencing using MiSeq platform (Illumina).We applied the quality ratio index (QR) to the GB, D, and every GBD mixture to integrate geochemical parameters with our microbiome data. QR indicated high environmental risk for GB and every GBD mixture, and low risk for D. The community shifted from aerobic to anaerobic profile, consistent with the characteristics of GB. Sample D was dominated by JTB255 marine benthic group, related to low impacted areas. Milano-WF1B-44 was the most representative of GB, often found in anaerobic and sulfur enriched environments. In GBD, the denitrifying sulfur-oxidizing bacteria, Sulfurovum, was the most representative, typically found in suboxic or anoxic niches. The canonical correspondence analysis was able to explain 60% of the community composition variation and exhibit the decrease of environmental quality as the contamination increases. Physiological and taxonomic shifts of the microbial assemblage in sediments were inferred by QR, which was suitable to determine sediment risk. The study produced sufficient information to improve the dredging plan and management.


Assuntos
Sedimentos Geológicos , Microbiota , Baías , Brasil , Monitoramento Ambiental , RNA Ribossômico 16S
2.
J Environ Manage ; 270: 110912, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32721346

RESUMO

Using agricultural biomasses as solid carbon substrates in constructed wetlands (CWs) could be an effective way to achieve sustainable nitrogen removal for carbon-limited wastewater treatments. This study investigated the response of bacteria community in CWs to the addition of agricultural biomasses (wheat straw, walnut shell and apricot pit). Results indicated that the addition of different agricultural biomasses had distinct influence on bacterial communities in CWs. Both wheat straw and walnut shell increased the diversity of microbial communities and optimized the structure of microorganisms. The effect of apricot pit on the richness and evenness of microbial communities was not significant, but the composition of microorganisms was significantly affected at the phylum level, especially the relative abundance of phylum Saccharibacteria. Moreover, the addition of agricultural biomasses in CWs acclimatized more functional bacteria including nitrifier and denitrifier, which were proved to be positively correlated with the high-rate denitrification performance. The obtained results would be beneficial to understand the underlying microbial mechanism of nitrogen removal in CWs with agricultural biomass and provide some guidance on the practical application of CWs.


Assuntos
Microbiota , Águas Residuárias , Biomassa , Carbono , Desnitrificação , Nitrogênio , Eliminação de Resíduos Líquidos , Áreas Alagadas
3.
Huan Jing Ke Xue ; 41(2): 839-848, 2020 Feb 08.
Artigo em Chinês | MEDLINE | ID: mdl-32608745

RESUMO

To solve the problems of a slow start, easy loss, and easily inhibited activity of the Anammox bacteria suspension culture, polyvinyl alcohol-polypropylene (PVA-PP) was used to prepare the Anammox immobilized filler. To improve the activity of Anammox bacteria and ensure stable operation of the reaction system, the effects of COD interference, change in pH value, and rotating speed on the nitrogen removal characteristics of the immobilized filler were determined in batch tests. Changes in the structure and diversity of the bacteria in the filler were analyzed by a high-throughput sequencing technique. The results showed that the activity of Anammox bacteria could recover to 100% on the 30th day, and the total nitrogen removal rate was 87.7% when the total nitrogen volume load (NLR) was 0.69 kg·(m3·d)-1 at the stage of 99 days. After 140 days of long-term operation, the total nitrogen removal rate (NRR) reached 1.83 kg·(m3·d)-1, which was 9.4 times the suspended sludge before immobilization. The diversity of the population was maintained in the inclusion carrier, and the effective enrichment of Candidatus Kuenenia (AF375995.1), which performs anaerobic ammonia-oxidization, increased from 11.06% to 32.55%. The influence of COD interference and changes in the pH value of Anammox bacteria was significantly weakened, and the PVA-PP entrapped carrier could achieve the coupling removal of nitrogen by Anammox and denitrification. Appropriate external hydraulic disturbance would promote the Anammox reaction in immobilized systems.


Assuntos
Compostos de Amônio/metabolismo , Bactérias/metabolismo , Microbiota , Nitrogênio/metabolismo , Anaerobiose , Bactérias/classificação , Reatores Biológicos , Células Imobilizadas/microbiologia , Desnitrificação , Oxirredução , Esgotos
4.
Huan Jing Ke Xue ; 41(2): 997-1004, 2020 Feb 08.
Artigo em Chinês | MEDLINE | ID: mdl-32608762

RESUMO

This study sets out to understand the evolution of the microbial community structure in industrial composting with livestock manure and peach branches. Pig manure, peach branches, and decomposed organic fertilizer were used as materials for composting. Changes in physical and chemical indicators and the evolution in the structure of the compost microbial community, determined by high-throughput sequencing, were analyzed. The results of physical and chemical parameters show that the pile reached the high-temperature stage on day 2, and the thermophilic period lasted for 30 days. The changes in total carbon were volatile, and there was an overall decline in the amount of TOC in the whole process of composting; The final content of TN was 20.58 g·kg-1, which was 5.90% lower compared to the initial compost. Alpha analysis indicated that a different microbial community diversity existed at different times during aerobic composting periods. At the bacterial phyla level, Firmicutes and Actinobacteria were the dominant phyla, and the proportion of relative abundance were 79.31%-95.09% and 2.98%-19.70%, respectively, in the entire compost. The relative abundance of Firmicutes and Actinobacteria were 87.36% and 9.66%, respectively, and their respective relative abundances were 79.38% and 19.70% at the end of composting. At the bacterial genus level, the dominant group changed from Clostridium_sensu_stricto_1, Terrisporobacter, and Bacillus to norank_f_Bacillaceae, Bacillus, Oceanbacillus, and Pseudogracilibacillus; Regarding the fungus phyla, the Ascomycota was the dominant phylum. For the fungus genus, the relative abundance of norank_c_Sordariomycetes gradually increased during composting, and finally was predominant group. The redundancy analysis (RDA) showed that the correlation rank between environmental factors and microbial community structure was:pH > NH4+-N > T > TOC > TN, where pH had the greatest impact on the microbial community composition. norank_c_Sordariomycetes, norank_o_Sordariales, and norank_c_Agaricomycetes may be related to the volatilization of ammonium nitrogen.


Assuntos
Compostagem , Esterco , Microbiota , Prunus persica , Animais , Gado , Solo , Suínos
6.
Ying Yong Sheng Tai Xue Bao ; 31(7): 2464-2472, 2020 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-32715714

RESUMO

Drought and nitrogen input are profoundly influencing most life on Earth and the substance cycling in forest ecosystems in the Anthropocene, with consequences on global carbon balance and feedback on climate changes. Soil microorganisms drive biogeochemical cycling and key ecological processes, with central role and global importance in climate change biology. Here, we reviewed the research in the area of the effects of drought and nitrogen deposition on soil bacteria and mycorrhizal fungi in forest ecosystems. We proposed that future studies should focus on how microbial diversity, activity, and ecological functioning respond to multiple global change factors and their interactions; how subtropical forest ecosystems respond to global changes on the basis of establishment of the long-term field experimental station; the interaction of different soil biological guilds; utilizing microbial big data to construct the relevant mechanistic models. Taken together, based on improved understanding of the responses of soil microbial diversity and community composition to global changes, further research may subsequently focus on manipulating the microbial communities to enhance forest management, ecological resources protection, and environmental sustainability. This review would provide some critical theoretical basis for the microbial strategy in mitigating climate change in future.


Assuntos
Microbiota , Solo , Secas , Ecossistema , Florestas , Nitrogênio/análise , Microbiologia do Solo
7.
Cell Host Microbe ; 28(1): 3-5, 2020 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-32645352

RESUMO

Ketogenic diets (KDs) are popularly used to aid a myriad of conditions. KDs induce metabolic changes, but how microbiome alterations contribute to these changes remains unexplored. In a recent Cell paper, Ang et al. identify KD-specific changes to the gut microbiota linked to a reduction in pro-inflammatory Th17 cells.


Assuntos
Dieta Cetogênica , Microbioma Gastrointestinal , Microbiota , Bifidobacterium , Células Th17
9.
Water Sci Technol ; 81(9): 1870-1881, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32666942

RESUMO

The effect of change of hydraulic characteristic and microbial community on pollution removal efficiency of the infiltration systems in the bioclogging development process remain poorly understood. In this study, therefore, the pollutant removal as a response to hydraulic conductivity reduction and the change of diversity and structure of microbial communities in vertical flow constructed wetlands (VFCWs) was investigated. The results indicated that the richness and diversity of the bacterial communities in the columns at different depths were decreased, and the microbial communities of the genus level were changed in the process of bioclogging. However, the variation of microbial communities has a low impact on the purification performance of VFCWs because the abundance of function groups, respiratory activity, and degradation potentiality of microorganisms remain steady or even get improved in the columns after bioclogging. On the contrary, the hydraulic efficiency of VFCWs decreased greatly by 16.9%, 9.9%, and 57.1% for VFCWs filled with zeolite (Column I), gravel (Column II), and ceramsite (Column III), respectively. The existence of short-circuiting and dead zones in the filter media cause the poor pollution removal efficiency of VFCWs due to the short contact time and decrease of oxygenation renewal, as well as low activity in the dead zone.


Assuntos
Microbiota , Áreas Alagadas , Bactérias , Nitrogênio
10.
Science ; 369(6499)2020 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-32631870

RESUMO

Microbial communities are essential to fundamental processes on Earth. Underlying the compositions and functions of these communities are nutritional interdependencies among individual species. One class of nutrients, cobamides (the family of enzyme cofactors that includes vitamin B12), is widely used for a variety of microbial metabolic functions, but these structurally diverse cofactors are synthesized by only a subset of bacteria and archaea. Advances at different scales of study-from individual isolates, to synthetic consortia, to complex communities-have led to an improved understanding of cobamide sharing. Here, we discuss how cobamides affect microbes at each of these three scales and how integrating different approaches leads to a more complete understanding of microbial interactions.


Assuntos
Cobamidas/metabolismo , Meio Ambiente , Interações Microbianas , Microbiota , Complexo Vitamínico B/metabolismo , Animais , Archaea/metabolismo , Bactérias/metabolismo , Cobamidas/química , Planeta Terra , Eucariotos/metabolismo , Modelos Biológicos , Complexo Vitamínico B/química
11.
Science ; 369(6499): 20-25, 2020 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-32631878
13.
Environ Monit Assess ; 192(8): 512, 2020 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-32661589

RESUMO

The objectives of this study were to analyze the difference in ways in which metals polluting Brazilian port areas influence bacterial communities and the selection of resistant strains. The hypothesis tested was that port areas would have microbial communities significantly different from a pristine area, mainly due to a greater load of metals found in these areas. Sediment samples were collected in two port areas (Santos and São Sebastião) and one pristine area (Ubatuba). Total DNA was extracted and MiSeq sequencing was performed. A hundred strains were isolated from the same samples and were tested for metal resistance. The community composition was similar in the two port regions, but differed from the pristine area. Microbial diversity was significantly lower in the port areas. The phyla Proteobacteria, Cyanobacteria, and Thermodesulfobacteria exhibited positive correlations with copper and zinc concentrations. Chloroflex, Nitrospirae, Planctomycetes, and Chlorobi exhibited negative correlations with copper, chromium, and zinc. Cr and Zn had higher concentrations at port areas and were responsible to select more metal-resistant strains. Some genera were found to be able to easily develop metal resistance. The most isolated genera were Bacillus, Vibrio, and Pseudomonas. This type of study can illustrate, even in very complex natural environments, the influence of pollution on the community as a whole and the consequences of these changes.


Assuntos
Metais Pesados/análise , Microbiota , Brasil , Monitoramento Ambiental , Poluição Ambiental/análise , Microbiologia do Solo
14.
Sci Total Environ ; 729: 138956, 2020 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-32498169

RESUMO

To handle the impact of habitat transformations, the microbial cells developed mechanisms aimed at adjustment of their biological processes in response to signals indicating environmental changes. One of the first changes in their properties is observed on their surface, which has direct contact with the dynamically varying surroundings. In this study, we present results of changes in the cell surface properties which may have a decisive impact on the xenobiotics' bioavailability and microbial cell survival. These changes influence their ability to remove xenobiotics by accelerating and empowering this process. Moreover, the application of microorganisms exposed for long-term to hydrocarbons in bioremediation processes might have positive impact on biodegradation of the latter in the natural environment as well as natural microbial community diversity. This study demonstrates a variety of microbial cell mechanisms of adaptation to long-term exposure to hydrocarbons and their potential as the bioremediation tools.


Assuntos
Bactérias , Biodegradação Ambiental , Água Doce , Hidrocarbonetos , Microbiota , RNA Ribossômico 16S
15.
J Environ Manage ; 268: 110708, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32510442

RESUMO

The formation of fat, oil, and grease (FOG) deposits in sewers is a global challenge for the maintenance of sewer collection systems. Tons of FOG deposits (FDs) are removed from sewer systems every year and present an opportunity for increased methane production via anaerobic co-digestion with waste activated sludge (WAS) at water resource recovery facilities with existing anaerobic digesters. We hypothesized that FDs have higher biomethane potential than that of FOG (e.g., FOG collected in grease interceptors), because of the reduction of inhibition of long chain fatty acids due to saponification. In this study, substantially enhanced methane production was found in anaerobic co-digestion of WAS with FDs within the substrate to inoculum (S/I) ratio range of 0.25-1.2, and the maximum ultimate methane production (685.7 ± 24.1 mL/gVSadded, at S/I = 0.5) was 4.0 times higher than in the control (with WAS only) after 42 days of incubation. Although the lag phase period was longer in FD co-digestion (S/I = 0.5) than in FOG co-digestion (S/I = 0.5) under the same organic loading (gVS) and two times the COD loading, the daily methane production rate became higher after Day 15 in FD co-digestion. Significantly higher cumulative methane production (10.2%, p < 0.05) was obtained in FD co-digestion than in FOG co-digestion after 42-days. Microbial community analysis revealed higher levels of Geobacter in FD co-digestion, possibly suggesting a role for direct interspecies electron transfer (DIET) between Methanosaeta and Geobacter. This work provides fundamental insights supporting anaerobic co-digestion of FDs with WAS, demonstrating the advantages of FDs compared to FOG as co-substrate for enhanced biomethane recovery.


Assuntos
Microbiota , Esgotos , Anaerobiose , Reatores Biológicos , Metano
16.
Sci Total Environ ; 726: 138682, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32481223

RESUMO

Although the ubiquitous presence of microplastics in various environments is increasingly well studied, knowledge of the effects of microplastics on ambient microbial communities is still insufficient. To estimate the response of soil bacterial community succession and temporal turnover to microplastic amendment, a soil microcosm experiment was carried out with polyethylene microplastics. The soil samples under control and microplastic amendment conditions were collected for sequencing analysis using Illumina MiSeq technology. Microplastic amendment was found to significantly alter soil bacterial community structure, and the community differences were increased linearly with the incubation time. Compared with the turnover rate of bacterial community in the control samples (0.0103, p < .05, based on Bray-Curtis similarity), the succession rate was significantly (p < .001) higher in the soil with microplastic amendment (0.0309, p < .001). In addition, the effects of microplastic amendment on the time-decay relationships (TDRs) on taxonomic divisions revealed considerable variations of TDRs values, indicating the effects were lineage dependent. Our results propose that the presence of microbial in soil ecosystem may lead to a faster succession rate of soil bacterial community, which provides new insights into the evolutionary consequences of microplastics in terrestrial environment.


Assuntos
Microbiota , Solo , Ecossistema , Microplásticos , Plásticos , Polietileno
17.
Sci Total Environ ; 735: 139554, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32492563

RESUMO

The drivers of global change, such as increasing drought and nutrient deposition, are affecting soils and their microbial communities in many different habitats, but how these factors interact remains unclear. Quercus ilex and Pinus sylvestris are two important tree species in Mediterranean montane areas that respond differently to drought, which may be associated with the soils in which they grow. We measured soil respiration and physiologically profiled microbial communities to test the impact of drought and subsequent recovery on soil function and diversity for these two species. We also tested whether the addition of nitrogen and phosphorus modified these effects. Drought was the stronger driver of changes to the soil communities, decreasing diversity (Shannon index), and evenness for both species and decreasing soil respiration for Q. ilex when N was added. Soil respiration for P. sylvestris during the drought period was positively affected by N addition but was not affected by water stress. P addition during the drought period did not affect soil respiration for either tree species but did interact with soil-water content to affect community evenness for P. sylvestris. The two species also differed following the recovery from drought. Soil respiration for Q. ilex recovered fully after the drought treatment ended but decreased for P. sylvestris, whereas the soil community was more resilient for P. sylvestris than Q. ilex. Nutrient addition did not affect respiration or community composition or diversity during the recovery period. Soil respiration was generally weakly positively correlated with soil diversity. We demonstrate that short-term water stress and nutrient addition can have variable effects on the soil communities associated with different tree species and that the compositions of the communities can become uncoupled from soil respiration. Overall, we show that drought may be a stronger driver of changes to soil communities than nitrogen or phosphorus deposition.


Assuntos
Microbiota , Quercus , Secas , Nitrogênio , Fósforo , Solo , Microbiologia do Solo , Árvores
18.
Sci Total Environ ; 736: 139588, 2020 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-32497884

RESUMO

Arctic lakes emit methane (CH4) to the atmosphere. The magnitude of this flux could increase with permafrost thaw but might also be mitigated by microbial CH4 oxidation. Methane oxidation in oxic water has been extensively studied, while the contribution of anaerobic oxidation of methane (AOM) to CH4 mitigation is not fully understood. We have investigated four Northern Siberian stratified lakes in an area of discontinuous permafrost nearby Igarka, Russia. Analyses of CH4 concentrations in the water column demonstrated that 60 to 100% of upward diffusing CH4 was oxidized in the anoxic layers of the four lakes. A combination of pmoA and mcrA gene qPCR and 16S rRNA gene metabarcoding showed that the same taxa, all within Methylomonadaceae and including the predominant genus Methylobacter as well as Crenothrix, could be the major methane-oxidizing bacteria (MOB) in the anoxic water of the four lakes. Correlation between Methylomonadaceae and OTUs within Methylotenera, Geothrix and Geobacter genera indicated that AOM might occur in an interaction between MOB, denitrifiers and iron-cycling partners. We conclude that MOB within Methylomonadaceae could have a crucial impact on CH4 cycling in these Siberian Arctic lakes by mitigating the majority of produced CH4 before it leaves the anoxic zone. This finding emphasizes the importance of AOM by Methylomonadaceae and extends our knowledge about CH4 cycle in lakes, a crucial component of the global CH4 cycle.


Assuntos
Lagos , Microbiota , Anaerobiose , Regiões Árticas , Metano/análise , Oxirredução , RNA Ribossômico 16S , Federação Russa , Água
19.
Sci Total Environ ; 728: 138856, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32570327

RESUMO

Particulate organic matter (POM) in aquatic ecosystem is critical for biogeochemical cycling and host distinct communities of microbes, compared to its surrounding water. In this study, the structures and functional potentials of microbial communities associated with particles or free-living in water samples from the Pearl River Estuary were investigated using 16S rRNA gene sequencing and GeoChip 5.0 analysis. Significant differences in the community structure and genetic functional potentials between particle-associated bacteria and free-living bacteria were observed across all eight sampling sites. In particle-associated bacteria communities, Rhodobacteraceae and Flavobacteriaceae were more abundant, while SAR11 clade and SAR86 clade were the most abundant in free-living bacteria communities. The richness and abundance of functional genes involved in nutrient cycling and stress response, including carbon degradation, nitrogen fixation, DMSP degradation, and polyphosphate degradation, were much higher in particle-associated bacteria compared with free-living bacteria. Thus, the particle-associated bacteria seem to play a much more important role in the biogeochemical cycles than free-living bacteria. In conclusion, the results from this study highlight the central role played by particle-associated bacteria in structuring microbial assemblages, and their importance for mediating biogeochemical cycling in the estuarine ecosystem.


Assuntos
Microbiota , Rios , Bactérias/genética , Estuários , RNA Ribossômico 16S
20.
Chemosphere ; 257: 127076, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32485516

RESUMO

The effect of acetate (HAc) and propionate (HPr) on denitrifying phosphorus removal (DPR) was evaluated in a novel two-sludge A2/O - MBBR (anaerobic/anoxic/oxic - moving bed biofilm reactor) system. Results showed that it was the carbon source transformation and utilization especially the composition of poly-ß-hydroxyalkanoates (PHA) (mainly poly-ß-hydroxybutyrate (PHB) and poly-bhydroxyvalerate (PHV)) decided DPR performance, where the co-exist of HAc and HPr promoted the optimal nitrogen (85.77%) and phosphorus (91.37%) removals. It facilitated the balance of PHB and PHV and removing 1 mg NO3- (PO43-) consumed 3.04-4.25 (6.84-9.82) mgPHA, where approximately 40-45% carbon source was saved. Mass balance revealed the main metabolic pathways of carbon (MAn,C (consumed amount in anaerobic stage) and MA-O,C (consumed amount in anoxic and oxic stages): 66.38-76.19%), nitrogen (MDPR,N (consumed amount in DPR): 57.01-65.75%), and phosphorus (MWS,P (discharged amount in waste sludge): 81.05-85.82%). Furthermore, the relative abundance and microbial distribution were assessed to elucidate DPR mechanism (e.g. Accumulibacter, Acinetobacter, Dechloromonas, Competibacter, and Defluviicoccus) in the A2/O reactor and nitrification performance (e.g. Nitrosomonas, Nitrosomonadaceae and Nitrospira) in the MBBR. Carbon source was demonstrated as the key point to stimulate the biodiversity and bioactivity related to DPR potential, and the operational strategy of carbon source addition was proposed based on the utilizing rules of HAc and HPr.


Assuntos
Eliminação de Resíduos Líquidos/métodos , Acetatos , Bactérias/metabolismo , Biofilmes , Reatores Biológicos , Carbono , Desnitrificação , Microbiota , Nitrificação , Nitrogênio/metabolismo , Nutrientes , Fósforo/metabolismo , Propionatos , Esgotos
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