scholarly journals Spatial Variations of Bacterial Communities of an Anaerobic Lagoon-Type Biodigester Fed with Dairy Manure

Processes ◽  
2019 ◽  
Vol 7 (7) ◽  
pp. 408 ◽  
Author(s):  
Marleny García-Lozano ◽  
Inty Omar Hernández-De Lira ◽  
David H. Huber ◽  
Nagamani Balagurusamy

Anaerobic digestion technology is being widely employed for sustainable management of organic wastes generated in animal farms, industries, etc. Nevertheless, biodigester microbiome is still considered a “black box” because it is regulated by different physico-chemical and operational factors. In this study, the bacterial diversity and composition in different sites of a full-scale lagoon type biodigester (23,000 m3) fed with dairy manure, viz., the influent, beginning, middle, final and effluent were analyzed. The biodigester registered a total of 1445 OTUs, which demonstrated the complex microbial ecosystem in it. Of them, only six OTUs were shared among all the different sampling points. The most abundant phyla belonged to Firmicutes, Proteobacteria, Latescibacteria and Thermotogae. The Simpson and Shannon index showed that the highest microbial diversity was observed in the beginning point of the biodigester, meanwhile, the lowest diversity was recorded in the middle. Based on the UniFrac distances, microbial communities with high similarity were recorded in the middle and final of the biodigester. It can be clearly observed that bacterial communities varied at the different points of the biodigester. However, based on metagenome predictions using PICRUSt, it was found that independent of the differences in taxonomy and location, bacterial communities maintained similar metabolic functions.

2021 ◽  
Vol 97 (3) ◽  
Author(s):  
Constantinos Xenophontos ◽  
Martin Taubert ◽  
W Stanley Harpole ◽  
Kirsten Küsel

ABSTRACT Quantifying the relative contributions of microbial species to ecosystem functioning is challenging, because of the distinct mechanisms associated with microbial phylogenetic and metabolic diversity. We constructed bacterial communities with different diversity traits and employed exoenzyme activities (EEAs) and carbon acquisition potential (CAP) from substrates as proxies of bacterial functioning to test the independent effects of these two aspects of biodiversity. We expected that metabolic diversity, but not phylogenetic diversity would be associated with greater ecological function. Phylogenetically relatedness should intensify species interactions and coexistence, therefore amplifying the influence of metabolic diversity. We examined the effects of each diversity treatment using linear models, while controlling for the other, and found that phylogenetic diversity strongly influenced community functioning, positively and negatively. Metabolic diversity, however, exhibited negative or non-significant relationships with community functioning. When controlling for different substrates, EEAs increased along with phylogenetic diversity but decreased with metabolic diversity. The strength of diversity effects was related to substrate chemistry and the molecular mechanisms associated with each substrate's degradation. EEAs of phylogenetically similar groups were strongly affected by within-genus interactions. These results highlight the unique flexibility of microbial metabolic functions that must be considered in further ecological theory development.


2020 ◽  
Author(s):  
Pedro E. Romero ◽  
Erika Calla-Quispe ◽  
Camila Castillo-Vilcahuaman ◽  
Mateo Yokoo ◽  
Hammerly Lino Fuentes-Rivera ◽  
...  

AbstractBackgroundThe Rimac river is the main source of water for Lima, Peru’s capital megacity. The river is constantly affected by different types of contamination including mine tailings in the Andes and urban sewage in the metropolitan area. We aim to produce the first characterization of bacterial communities in the Rimac river using a 16S rRNA amplicon sequencing approach which would be useful to identify bacterial diversity and potential understudied pathogens.ResultsWe report a higher diversity in bacterial communities from the Upper and, especially, Middle Rimac compared to the Lower Rimac (Metropolitan zone). Samples were generally grouped according to their geographical location. Bacterial classes Alphaproteobacteria, Bacteroidia, Campylobacteria, Fusobacteriia, and Gammaproteobacteria were the most frequent along the river. Arcobacter cryaerophilus (Campylobacteria) was the most frequent species in the Lower Rimac while Flavobacterium succinicans (Bacteroidia) and Hypnocyclicus (Fusobacteriia) were the most predominant in the Upper Rimac. Predicted metabolic functions in the microbiota include bacterial motility, quorum sensing and xenobiotics metabolism. Additional metabolomic analyses showed the presence natural flavonoids and antibiotics in the Upper Rimac, and herbicides in the Lower Rimac.ConclusionsThe dominance in the Metropolitan area of Arcobacter cryaerophilus, an emergent pathogen associated with fecal contamination and antibiotic multiresistance, but that is not usually reported in traditional microbiological quality assessments, highlights the necessity to apply next-generation sequencing tools to improve pathogen surveillance. We believe that our study will encourage the integration of omics sciences in Peru and its application on current environmental and public health issues.


2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 163-164
Author(s):  
Caleb P Weiss ◽  
Paul A Beck ◽  
John T Richeson ◽  
Dexter J Tomczak ◽  
Jianmin Chai ◽  
...  

Abstract Three monensin levels during a stocker phase (0, 800, 1600 g/ton fed in a free choice mineral) and two levels during finishing [0 (U) or 37.5 mg/kg diet DM (M)] were used to determine the effects of monensin supplementation during a stocker and subsequent finishing phase on rumen bacterial communities of beef steers. Thirty calves were fed pearl millet (Pennisetum glaucum) hay with soybean hull and corn gluten feed supplement (0.5% BW daily, AF basis) or grazed fall wheat pasture (Triticum aestivum) during a stocker phase and then transported 1,067 km to Canyon, TX, for finishing. Rumen fluid was collected on d 0, 28, and the end of the stocker phase (d 85). Samples were also obtained at feedlot d 0, 14, 28, 56, and immediately prior to a diet change to include a beta-adrenergic agonist and before shipping for harvest. Rumen microbiota were characterized by next generation sequencing the 16S v4 hypervariable region with the Illumina MiSeq platform. During the stocker phase, Prevotella and Bacteroidetes were the most dominant genus regardless of diet or treatment. Monensin decreased (P ≤ 0.01) alpha diversity (Shannon Index) for cattle consuming hay on d 28 of the stocker phase. In the feedlot, Prevotella, Lachnospiraceae, and Bacteroidetes were the most abundant genus. Steers that were previously on the 0 and 1600 treatments during the stocker phase and were fed monensin at the feedlot had decreased alpha diversity (P = 0.04) on feedlot d 14 compared to those that did not. Monensin at the feedlot tended to increase alpha diversity on d 28 for cattle previously on the 1600 treatment (P = 0.06), and on d 56 for cattle previously on the 0 treatment (P = 0.06). This experiment provides a better understanding of the effect of monensin on rumen bacterial communities throughout production.


Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3077 ◽  
Author(s):  
Katerin Almendras ◽  
Jaime García ◽  
Margarita Carú ◽  
Julieta Orlando

Lichens have been extensively studied and described; however, recent evidence suggests that members of the bacterial community associated with them could contribute new functions to the symbiotic interaction. In this work, we compare the nitrogen-fixing guild associated with bipartite terricolous lichens with different types of photobiont: Peltigera cyanolichens and Cladonia chlorolichens. Since cyanobacteria contribute nitrogen to the symbiosis, we propose that chlorolichens have more diverse bacteria with the ability to fix nitrogen compared to cyanolichens. In addition, since part of these bacteria could be recruited from the substrate where lichens grow, we propose that thalli and substrates share some bacteria in common. The structure of the nitrogen-fixing guild in the lichen and substrate bacterial communities of both lichens was determined by terminal restriction fragment length polymorphism (TRFLP) of the nifH gene. Multivariate analyses showed that the nitrogen-fixing bacteria associated with both types of lichen were distinguishable from those present in their substrates. Likewise, the structure of the nitrogen-fixing bacteria present in the cyanolichens was different from that of chlorolichens. Finally, the diversity of this bacterial guild calculated using the Shannon index confirms the hypothesis that chlorolichens have a higher diversity of nitrogen-fixing bacteria than cyanolichens.


2018 ◽  
Vol 37 ◽  
pp. 01008 ◽  
Author(s):  
Karim Arifi ◽  
Latifa Tahri ◽  
Abdallah El Abid ◽  
Fatima Zahra Hefiane ◽  
Souad Elblidi ◽  
...  

The Grou River is one of the main rivers that feed the reservoir of the Sidi Mohammed Ben Abdellah (SMBA) dam in Morocco. However, this river is particularly threatened by the pollution problem. It is in this context that this study aims to study the effect of wastewater from the rural commune of Jmaa Moulblad on the physicochemical quality of the waters of this river. We analyzed 11 physicochemical parameters (T° of area, T° of water, pH, EC, mV, Sal, TDS, BOD, COD, SS and TOC), with a monthly frequency since the month of December 2014 until November 2015. The results obtained show a worrying situation of the state of this watercourse. To remedy this problem, we recommend pre-treatment of wastewater before discharge and the implementation of a management plan and sustainable management of the Grou River watershed.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jianguo Guo ◽  
Yi Xiong ◽  
Taisheng Kang ◽  
Hua Zhu ◽  
Qiwen Yang ◽  
...  

AbstractIndoor formaldehyde (CH2O) exceeding the recommended level is a severe threat to human health. Few studies have investigated its effect on indoor surface bacterial communities, affecting habitants' health. This study used 20-L glass containers to mimic the indoor environment with bacterial inputs from human oral respiration. The behavior of bacterial communities responding to CH2O varied among the different CH2O levels. The bacterial community structure significantly changed over time in the 0.054 mg·m−3 CH2O group, which varied from the 0.1 mg·m−3 and 0.25 mg·m−3 CH2O groups. The Chao1 and Shannon index significantly increased in the 0.054 mg·m−3 CH2O group at 6 week, while they remained unchanged in the 0.25 mg·m−3 CH2O group. At 12 week, the Chao1 significantly increased in the 0.25 mg·m−3 CH2O group, while it remained unchanged in the 0.054 mg·m−3 CH2O group. Only a few Operational Taxonomic Units (OTUs) significantly correlated with the CH2O concentration. CH2O-induced OTUs mainly belong to the Proteobacteria and Firmicutes. Furthermore, bacterial communities formed at 6 or 12 weeks differed significantly among different CH2O levels. Functional analysis of bacterial communities showed that inferred genes related to chemical degradation and diseases were the highest in the 0.25 mg·m−3 CH2O group at 12 weeks. The development of nematodes fed with bacteria collected at 12 weeks was applied to evaluate the bacterial community's hazards. This showed significantly impaired growth in the 0.1 mg·m−3 and 0.25 mg·m−3 CH2O groups. These findings confirmed that CH2O concentration and exposure time could affect the indoor bacterial community and formed bacterial communities with a possibly more significant hazard to human health after long-term exposure to high CH2O levels.


2020 ◽  
Author(s):  
Juntao Zhang ◽  
Xiying Huang ◽  
Menggen Ma ◽  
Quanju Xiang ◽  
Ke Zhao ◽  
...  

Abstract Background:Silage fermentation, a sustainable way to use vegetable waste resources, is a complex process driven by a variety of microorganisms. We used lettuce waste as the raw material for silage, analyzed changes in the physico-chemical characteristics and bacterial community composition of silage during a 60 day fermentation, identified differentially abundant taxa, predicted the functional profiles of bacterial communities, and determined the associated effects on the quality of silage. Results: The biggest changes occurred in the early stage of silage fermentation. Changes in the physico-chemical characteristics included a decrease in pH and increases in ammonia nitrogen to total nitrogen ratio and lactic acid content. The numbers of lactic acid bacteria increased and those of molds, yeasts and aerobic bacteria decreased. The bacterial communities and their predicted functions on day 0 were clearly different from those on day 7 to day 60. The relative abundances of phylum Firmicutes and genus Lactobacillus increased. Nitrite ammonification and nitrate ammonification were more prevalent after day 0. The differences in the predicted functions were associated with differences in pH and amino acid, protein, carbohydrate, NH3-N, ether extract and crude ash contents. Conclusion: Firmicutes and Lactobacillus were the dominant taxa during vegetable waste silage fermentation. The microbial communities and the predicted functions changed in different stages of silage fermentation, and the changes were accompanied with changes in the physico-chemical characteristics, especially with a decrease in pH and increases in ammonia nitrogen to total nitrogen ratio and lactic acid content.


Author(s):  
Anneloes E. Groenenboom ◽  
John Shindano ◽  
Nachimuka Cheepa ◽  
Eddy J. Smid ◽  
Sijmen E. Schoustra

AbstractMabisi is a fermented milk product, traditionally produced in a calabash by uncontrolled fermentation. Due to high costs and a reduced availability of calabashes, nowadays plastic containers are also used for Mabisi production. However, the effect of this change in production practice on the properties of the product has not been documented. Therefore, we aimed at determining the effect of fermentation vessels and types of back-slopping on acidification and microbial communities during fermentation. A series of fifteen experiments using two types of fermentation vessels (plastic buckets and calabashes) in combination with different types of back-slopping (no back-slopping, passive back-slopping, and active back-slopping) were set up at a field site in rural Zambia. In each of the fifteen fermentations we analysed acidification rate of traditional Mabisi fermentation and bacterial diversity over time. No significant difference was found in terms of microbial diversity during and at the end of fermentation between fermentations performed in buckets or previously used calabashes. Bacterial communities in general decreased in diversity over time, where the drop in pH correlated with a decrease in Shannon Index. In case of active back-slopping, the pH drop started right after inoculation while in the no back-slopping and passive back-slopping fermentations, there was a clear lag phase before acidification started. All experimental series resulted in a microbial community dominated by Lactococcus lactis and a Shannon Index, as a measure for diversity, between 0.6 and 2.0. The use of plastic buckets for Mabisi fermentation can be a valuable alternative to the use of calabashes as this study showed no biological and physico-chemical differences between Mabisi resulting from both fermentation vessels, although the reason for perceived differences should be further investigated.


2012 ◽  
Vol 21 (2) ◽  
pp. 169-175 ◽  
Author(s):  
Mohammad Zabed Hossain ◽  
Chaman Binta Aziz ◽  
Mihir Lal Saha

Although soil bacterial communities are one of the important biotic components that influence decomposition and nutrient mineralization in the terrestrial ecosystems, factors driving this biotic community in the Sunderban mangrove forests are not well studied. The present study examined the importance of soil physico?chemical properties in driving soil bacterial communities in the Sunderban mangrove forests, Bangladesh. Soils were collected from 12 locations under four sites, namely Koromjal, Kotka, Hironpoint, and Dublarchar of Sunderban forests. Results showed a large range of variation in total bacterial colony counts (7.65 × 104 ? 14.5 × 104 cfu/g soil), soil moisture (9.0 ? 27.0%), total nitrogen (0.057 ? 0.158%), available nitrogen (0.504 ? 2.016 ?g/g soil), soil salinity (20.99 ? 34.99 mg chloride/g soil), and organic carbon (0.460 ? 0.885%). Data of the present study revealed that the number of total viable bacterial count was significantly and positively correlated only with total nitrogen content in soil indicating that total nitrogen content is the major driving factor of bacterial communities in the Sunderban mangrove forest soils.DOI: http://dx.doi.org/10.3329/dujbs.v21i2.11515 Dhaka Univ. J. Biol. Sci. 21(2): 169-175, 2012 (July)


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Edoardo Puglisi ◽  
Francesco Romaniello ◽  
Serena Galletti ◽  
Enrico Boccaleri ◽  
Alberto Frache ◽  
...  

Abstract The microbial colonization of plastic wastes has been extensively studied in marine environments, while studies on aged terrestrial wastes are scarce, and mostly limited to the isolation of plastic-degrading microorganisms. Here we have applied a multidisciplinary approach involving culturomics, next-generation sequencing analyses and fine-scale physico-chemical measurements to characterize plastic wastes retrieved in landfill abandoned for more than 35 years, and to assess the composition of bacterial communities thriving as biofilms on the films’ surfaces. All samples were characterized by different colors but were all of polyethylene; IR and DSC analyses identified different level of degradation, while FT-Raman spectroscopy and X-ray fluorescence further assessed the degradation level and the presence of pigments. Each plastic type harbored distinct bacterial communities from the others, in agreement with the differences highlighted by the physico-chemical analyses. Furthermore, the most degraded polyethylene films were found to host a bacterial community more similar to the surrounding soil as revealed by both α- and β-diversity NGS analyses. This work confirms the novel hypothesis that different polyethylene terrestrial waste samples select for different bacterial communities, and that structure of these communities can be correlated with physico-chemical properties of the plastics, including the degradation degree.


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