scholarly journals Metagenomic Study of Bacterial and Archaeal Populations during Anaerobic Digestion of Lignocellulosic Waste in Lab-scale Biogas Reactors

2020 ◽  
Vol 1 (5) ◽  
Author(s):  
Uduak U. Ndubuisi-Nnaji ◽  
Ata O. Inyang-Enin ◽  
Utibe A. Ofon ◽  
Osagie Ibhadode
Keyword(s):  
Bacterial Community ◽  
Archaeal Community ◽  
Taxonomic Composition ◽  
Untreated Sample ◽  
Volatile Solids ◽  
Biogas Reactors ◽  
Vs Removal ◽  
Removal Efficiencies ◽  
Microbial Groups ◽  
Banana Stem

This study evaluated using 16S rDNA gene-based metagenomics technique the populations of bacteria and archaea in digestate samples from lab-scale anaerobic bioreactors digesting pretreated and untreated coconut husk fiber, pineapple floret and banana stem. Result of biodegradability experiment indicated high microbial activity in digestate (biogas slurry), with untreated banana stem having the highest total solids (TS) and volatile solids (VS) removal efficiencies of 78.3 % and 92.9 % respectively. Similarly, all pretreated substrates exhibited higher TS and VS losses with corresponding TS (77.8 %) and VS (87.2 %) removal efficiencies. This TS and VS removal rates signaled increased rate of organic matter decomposition with concomitant biogas productivity. Diversity comparisons performed between samples showed rich microbial diversity in untreated sample than the pretreated sample. Taxonomic composition revealed that, for untreated samples at the phylum level, the bacterial community was predominantly Firmicutes (relative abundance 97.0 %), with 0.30 % Actinobacteria and 0.10 % Proteobacteria. The genus Oxobacter (35.0 %), Clostridium (12.0 %) and Ethanoligenens (10.0 %) were ubiquitous and abundant in the untreated sample. The archaeal community was however dominated by the Euryarchaeota with one methanogenic order Methanomicrobiales, and a high abundance of the genera Thermacetogenium. For pretreated samples, at the phylum level, bacterial community was also dominated by Firmicutes (95.0 %), followed by Proteobacteria (1.02 %), Actinobacteria (0.18 %) and Tenericutes (0.06 %). The genus Clostridium (41.0 %), Ethanoligenens (29.0 %) and Lactobacillus (15.0 %) were also ubiquitous and abundant in the pretreated sample. Archaeal community was also dominated by Euryarchaeota with the two methanogenic orders Methanomicrobiales and Methanosarcinales dominating. The major microbial groups were hydrolyzing and fermenting populations. These findings revealed rich microbial assemblage and diversity among microbial communities in biogas digestate.

Effects on anaerobic digestion of sewage sludge pretreatment

1997 ◽  
Vol 35 (10) ◽  
pp. 207-211 ◽  
Author(s):  
H. B. Choi ◽  
K. Y. Hwang ◽  
E. B. Shin
Keyword(s):  
Anaerobic Digestion ◽  
Protein Concentration ◽  
Operating Conditions ◽  
Waste Activated Sludge ◽  
Batch Experiments ◽  
Mechanical Pretreatment ◽  
Sludge Pretreatment ◽  
Volatile Solids ◽  
Vs Removal ◽  
Removal Efficiencies

This research investigates the effect of sludge pretreatment on the anaerobic digestion of waste-activated sludge (WAS). In the key of this sludge pretreatment process, bacteria in the WAS were ruptured by mechanical jet and smashed under pressurized conditions. The protein concentrations in the sludge varied significantly after pretreatment. Protein concentration increased according to jet times and pressure. In batch experiments, volatile solids (VS) removal efficiencies were 13∼50% when the WAS pretreated once under 30 bar was fed into an anaerobic digester with 2∼26 day retention time. In the same operating conditions, when intact WAS was fed into the digester, VS removal efficiencies were 2∼35%. Therefore, it is recognized that higher digestion efficiencies of the WAS were obtained through a mechanical pretreatment of sludge.

Effects of experimental parameters on methane production and volatile solids removal from tomato and pepper plant wastes

BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 4763-4780
Author(s):  
Saraí Camarena-Martínez ◽  
Juan H. Martínez-Martínez ◽  
Adriana Saldaña-Robles ◽  
Hector G. Nuñez-Palenius ◽  
Rogelio Costilla-Salazar ◽  
...  
Keyword(s):  
Methane Production ◽  
Methane Yield ◽  
Pepper Plant ◽  
Limited Information ◽  
Total Solids ◽  
Volatile Solids ◽  
Vs Removal ◽  
Solids Content ◽  
Solids Removal ◽  
Positive Effect

In Mexico, protected agriculture generates large amounts of tomato and pepper plants residues (TPW and PPW, respectively). Given the limited information on methane production from anaerobic digestion of these wastes, this study aimed to determine the effects of the substrate/inoculum (S/I) ratio, temperature, and total solids content on methane production and volatile solids (VS) removal by two subsequent batch experiments (Experiments A and B). Experiment A was performed to evaluate the substrate/inoculum ratios of 0.5, 1.0, and 2.0 at room temperature (22 ± 4.5 °C). Based on the best methane yield from experiment A, a new experiment was established (Experiment B) using only tomato wastes, where temperature was kept at 29 °C and 39 °C. The total solids content was analyzed depending on the S/I ratio used. For both substrates, an S/I ratio of 0.5 was the most appropriate for methane production. The temperature had a positive effect on volatile solids removal and methane yield. In contrast, the total solids content (% TS) only had a positive effect on methane production. To the authors’ knowledge, this is the first study evaluating the effect of the S/I ratio on methane production from tomato and pepper plant wastes.

Manganese removal efficiencies and bacterial community profiles in non-bioaugmented and in bioaugmented sand filters exposed to different temperatures

2020 ◽  
Vol 36 ◽  
pp. 101261 ◽  
Author(s):  
Lucila Ciancio Casalini ◽  
Ainelén Piazza ◽  
Fiorella Masotti ◽  
Virginia A. Pacini ◽  
Graciela Sanguinetti ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Sand Filters ◽  
Manganese Removal ◽  
Different Temperatures ◽  
Removal Efficiencies

scholarly journals Propionate Converting Anaerobic Microbial Communities Enriched from Distinct Biogeochemical Zones of Aarhus Bay, Denmark under Sulfidogenic and Methanogenic Conditions

2020 ◽  
Vol 8 (3) ◽  
pp. 394 ◽  
Author(s):  
Derya Ozuolmez ◽  
Alfons J. M. Stams ◽  
Caroline M. Plugge
Keyword(s):  
Bacterial Community ◽  
Sulfate Reduction ◽  
Marine Sediments ◽  
Archaeal Community ◽  
Community Analysis ◽  
Different Temperatures ◽  
Propionate Degradation ◽  
Whole Sediment ◽  
The Relationship ◽  
Sediment Bacterial Community

The relationship between predominant physiological types of prokaryotes in marine sediments and propionate degradation through sulfate reduction, fermentation, and methanogenesis was studied in marine sediments. Propionate conversion was assessed in slurries containing sediment from three different biogeochemical zones of Aarhus Bay, Denmark. Sediment slurries were amended with 0, 3, or 20 mM sulfate and incubated at 25 °C and 10 °C for 514–571 days. Methanogenesis in the sulfate zone and sulfate reduction in the methane zone slurries was observed. Both processes occurred simultaneously in enrichments originating from samples along the whole sediment. Bacterial community analysis revealed the dominance of Desulfobacteraceae and Desulfobulbaceae members in sulfate-amended slurries incubated at 25°C and 10°C. Cryptanaerobacter belonging to the Peptococcaceae family dominated sulfate-free methanogenic slurries at 25°C, whereas bacteria related to Desulfobacteraceae were dominant at 10°C. Archaeal community analysis revealed the prevalence of different genera belonging to Methanomicrobiales in slurries incubated at different temperatures and amended with different sulfate concentrations. Methanosarcinaceae were only detected in the absence of sulfate. In summary, Aarhus Bay sediment zones contain sulfate reducers, syntrophs, and methanogens interacting with each other in the conversion of propionate. Our results indicate that in Aarhus Bay sediments, Cryptanaerobacter degraded propionate in syntrophic association with methanogens.

Growth of faecal coliforms and Salmonella spp. in physicochemical sludge treated with acetic acid

2001 ◽  
Vol 44 (10) ◽  
pp. 85-90 ◽  
Author(s):  
J.A. Barrios ◽  
B. Jiménez ◽  
S. Salgado ◽  
A. Garibay ◽  
A. Castrejon
Keyword(s):  
Acetic Acid ◽  
Bacterial Growth ◽  
Primary Treatment ◽  
Faecal Coliforms ◽  
Initial Value ◽  
Salmonella Spp ◽  
Untreated Sample ◽  
Volatile Solids ◽  
Growth Ph ◽  
Different Doses

The use of advanced primary treatment (APT) to remove helminth ova from wastewater has raised the issue of treating the generated sludge to allow its reuse or disposal. Several studies have been performed in Mexico in order to treat the sludge with the main goal of destroying helminth ova and bacteria, one of them analysing the acid treatment. Previous research has demonstrated the feasibility of applying such a process using acetic acid to disinfect the sludge, but the potential for bacterial growth was still to be proved. The results of a growth study of faecal coliforms and Salmonella spp. in sludge treated with acetic acid are presented in this paper. Physicochemical sludge generated in a semi-rural area of Mexico City was treated using acetic acid in 6 different doses ranging from 3,700 to 22,000 ppm (w/w) and the concentrations of faecal coliforms, Salmonella spp., and total and volatile solids, were monitored after 30 minutes, and 8, 21 and 35 days. Average initial concentrations in sludge were 1.1×108 MPN/g TS and 1.5×105 MPN/g TS for faecal coliforms and Salmonella spp., while pH, total and volatile solids were 5.4, 5.0% and 73% respectively. Apparently, some acidified samples presented anaerobic activity, observed as a change in sludge coloration, as well as bacterial growth. pH of the treated samples with less than 18,400 ppm raised from the initial value of approximately 4.0 up to 5.9 units, while samples with 18,400 and 22,000 ppm maintained the pH close to 4. Total and volatile solids did not present important changes except in the untreated sample where they were reduced by 0.3 and 3.4% respectively. Samples treated with more than 14,700 ppm of acetic acid did not present any increase in bacterial density. Additionally, concentrations of faecal coliforms and Salmonella spp. in untreated sludge were reduced throughout the time, in contrast to samples treated with doses lower than 14,700 ppm that showed some growth, which suggests that the use of acetic acid in doses lower than 15,000 ppm stimulates in some way the growth of these bacteria.

scholarly journals Enhanced biogas production potential of microalgae and swine wastewater using co-digestion and alkaline pretreatment

2018 ◽  
Vol 78 (1) ◽  
pp. 92-102 ◽  
Author(s):  
K. Panyaping ◽  
R. Khiewwijit ◽  
P. Wongpankamol
Keyword(s):  
Biogas Production ◽  
Oxygen Demand ◽  
Electrical Energy ◽  
Pilot Scale ◽  
Major Effect ◽  
Alkaline Pretreatment ◽  
Swine Wastewater ◽  
Biogas Yield ◽  
Volatile Solids ◽  
Vs Removal

Abstract Biogas yield obtained from anaerobic digestion of swine wastewater (SWW) needs to be increased to produce electrical energy. To enhance biogas and prevent pollution, use of mixed culture microalgae grown in wastewater (MWW) with SWW has attracted a lot of interest. This research was focused on the possibility of utilizing MWW. Six experiments using raw SWW and MWW, and their co-digestion were conducted on a laboratory scale in one-litre reactors with the ratio of inoculum and substrate of 70:30 under without and with alkaline pretreatment (using 3% NaOH for pH adjustment every 15 min at pH 11 for 3 h). The results showed that co-digestion had the major effect on increasing biogas and methane yields (0.735 and 0.326 m3/kg of volatile solids (VS) removed), and the highest chemical oxygen demand and VS removal (60.29% and 63.17%). For pretreatment, the effect of ammonia inhibition at a high pH of 11 had more influence on biodegradation than the effect of destruction of MWW's cell walls, resulting in a low biogas production of pretreated MWW and pretreated co-digestion. These findings affirm the potential of co-digestion, and the possibility of using both single and co-substrate MWW. Pretreatment could be improved at a lower alkaline pH condition. A pilot scale of co-digestion should be performed.

scholarly journals The chronic wound virome: phage diversity and associations with wounds and healing outcomes

2022 ◽  
Author(s):  
Samuel Verbanic ◽  
John Deacon ◽  
Irene A. Chen
Keyword(s):  
Bacterial Community ◽  
Chronic Wounds ◽  
Chronic Wound ◽  
Wound Care ◽  
Bacterial Community Composition ◽  
Taxonomic Composition ◽  
Metagenomic Sequencing ◽  
Care Clinic ◽  
Before And After ◽  
And Function

Two leading impediments to chronic wound healing are polymicrobial infection and biofilm formation. Recent studies have characterized the bacterial fraction of these microbiomes and have begun to elucidate compositional correlations to healing outcomes. However, the factors that drive compositional shifts are still being uncovered. The virome may play an important role in shaping bacterial community structure and function. Previous work on the skin virome determined that it was dominated by bacteriophages, viruses that infect bacteria. To characterize the virome, we enrolled 20 chronic wound patients presenting at an outpatient wound care clinic in a microbiome survey, collecting swab samples from healthy skin and chronic wounds before and after a single, sharp debridement procedure. We investigated the virome using a virus-like particle enrichment procedure, shotgun metagenomic sequencing, and a k-mer-based, reference-dependent taxonomic classification method. Taxonomic composition, diversity, and associations to covariates are presented. We find that the wound virome is highly diverse, with many phages targeting known pathogens, and may influence bacterial community composition and functionality in ways that impact healing outcomes.

scholarly journals The skin microbiome of elasmobranchs follows phylosymbosis, but in teleost fishes the microbiomes converge

2020 ◽  
Author(s):  
Michael Doane ◽  
Megan M. Morris ◽  
Bhavya Papudeshi ◽  
Lauren Allen ◽  
Dnyanada Pande ◽  
...  
Keyword(s):  
Teleost Fish ◽  
Divergence Time ◽  
Skin Surface ◽  
Taxonomic Composition ◽  
Skin Microbiome ◽  
Functional Composition ◽  
Teleost Fishes ◽  
Shotgun Metagenomics ◽  
Microbial Groups ◽  
Species Specific

Abstract Background: The vertebrate clade diverged into Chondrichthyes (sharks, rays, and chimeras) and Osteichthyes fishes (bony fishes) approximately 420 mya, with each group accumulating vast anatomical and physiological differences, including skin properties. The skin of Chondrichthyes fishes is covered in dermal denticles, whereas Osteichthyes fishes are covered in scales and are mucous rich. The divergence time among these two fish groups is hypothesized to result in predictable variation among symbionts. Here, using shotgun metagenomics, we test if patterns of diversity in the skin surface microbiome across the two fish clades match predictions made by phylosymbiosis theory. We hypothesize, 1) the skin microbiome will be species and clade-specific, 2) evolutionary difference in elasmobranch and teleost fishes corresponds with a concomitant increase in host-microbiome dissimilarity and 3) the skin structure of the two groups will affect the taxonomic and functional composition of the microbiomes. Results: We show that the taxonomic and functional composition of the microbiomes is host species-specific. Teleost fish had lower average microbiome within clade similarity compared to among clade comparison, but their composition is not different among clade in a null based model. Elasmobranch’s average similarity within clade was not different than across clade and not different in a null based model of comparison. In the comparison of host distance with microbiome distance, we found that the taxonomic composition of the microbiome was related to host distance for the elasmobranchs, but not the teleost fishes. In comparison, the gene function composition was not related to the host-organism distance for elasmobranchs but was negatively correlated with host distance for teleost fishes. Conclusion: Our results show the patterns of phylosymbiosis are not consistent across both fish clades, with the elasmobranchs showing phylosymbiosis, while the teleost fish are not. The discrepancy may be linked to alternative processes underpinning microbiome assemblage, including possible historical host-microbiome evolution of the elasmobranchs and convergent evolution in the teleost which filter specific microbial groups. Our comparison of the microbiomes among fishes represents an investigation into the microbial relationships of the oldest divergence extant vertebrate host and reveals that microbial relationships are not consistent across evolutionary timescales.

scholarly journals Effects of Long-term Cotton Continuous Cropping on Soil Microbiome

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Hui Xi ◽  
Jili Shen ◽  
Zheng Qu ◽  
Dingyi Yang ◽  
Shiming Liu ◽  
...  
Keyword(s):  
Severe Disease ◽  
Soil Microbial Communities ◽  
Alpha Diversity ◽  
Taxonomic Composition ◽  
Soil Microbiome ◽  
Continuous Cropping ◽  
Bacterial Phyla ◽  
Soil Microbial ◽  
Microbial Groups

AbstractVerticillium wilt is a severe disease of cotton crops in Xinjiang and affecting yields and quality, due to the continuous cotton cropping in the past decades. The relationship between continuous cropping and the changes induced on soil microbiome remains unclear to date. In this study, the culture types of 15 isolates from Bole (5F), Kuitun (7F), and Shihezi (8F) of north Xinjiang were sclerotium type. Only isolates from field 5F belonged to nondefoliating pathotype, the others belonged to defoliating pathotype. The isolates showed pathogenicity differentiation in cotton. Fungal and bacterial communities in soils had some difference in alpha-diversity, relative abundance, structure and taxonomic composition, but microbial groups showed similarity in the same habitat, despite different sampling sites. The fungal phyla Ascomycota, and the bacterial phyla Proteobacteria, Actinobacteria, Chloroflexi, Acidobacteria and Gemmatimonadetes were strongly enriched. Verticillium abundance was significantly and positively correlated with AN, but negatively correlated with soil OM, AK and pH. Moreover, Verticillium was correlated in abundances with 5 fungal and 6 bacterial genera. Overall, we demonstrate that soil microbiome communities have similar responses to long-term continuous cotton cropping, providing new insights into the effects of continuous cotton cropping on soil microbial communities.

Sign in / Sign up

Export Citation Format

Share Document