The Impact of Exogenous Aerobic Bacteria on Sustainable Methane Production Associated with Municipal Solid Waste Biodegradation: Revealed by High-Throughput Sequencing

Abstract

In this work, the impact of exogenous aerobic bacteria mixture (EABM) on municipal solid waste (MSW) is well evaluated in the following aspects: biogas production, leachate analysis, organic waste degradation, EABM population, and the composition of microbial communities. The study was designed and performed as follows: the control bioreactor (R1) was filled up with MSW and the culture medium of EABM and the experimental bioreactor (R2) was filled up with MSW and EABM. The data suggests that the composition of microbial communities (bacterial and methanogenic) in R1 and R2 were similar at day 0, while the addition of EABM in R2 led to a differential abundance of Bacillus cereus, Bacillus subtilis, Staphylococcus saprophyticus, Staphlyoccus xylosus, and Pantoea agglomerans in two bioreactors. The population of exogenous aerobic bacteria in R2 greatly increased during hydrolysis and acidogenesis stages, and subsequently increased the degradation of volatile solid (VS), protein, lipid, and lignin by 59.25%, 25.68%, 60.47%, and 197.62%, respectively, compared to R1. The duration of hydrolysis and acidogenesis in R2 was 33.33% shorter than that in R1. At the end of the study, the accumulative methane yield in R2 (494.4 L) was almost three times more than that in R1 (187.4 L). In addition, the abundance of acetoclasic methanogens increased at acetogenesis and methanogenesis stages in both bioreactors, which indicates that acetoclasic methanogens (especially Methanoseata) could contribute to methane production. This study demonstrates that EABM can accelerate organic waste degradation to promote MSW biodegradation and methane production. Moreover, the operational parameters helped EABM to generate 20.85% more in accumulative methane yield. With a better understanding of how EABM affects MSW and the composition of bacterial community, this study offers a potential practical approach to MSW disposal and cleaner energy generation worldwide.

Mining the Microbiome of Key Species from African Savanna Woodlands: Potential for Soil Health Improvement and Plant Growth Promotion

“…Additionally, P. agglomerans is a promising multifunctional microorganism in biorefineries, namely in converting the hemicellulose fraction of plant biomass into valued-added products [ 108 ] and in producing plant-based food ingredients [ 109 ]. It is also a source of antibiotics against multidrug-resistant bacteria [ 110 ] and able to degrade waste [ 111 ]. Finally, S. maltophilia seems to be promising in medical therapy [ 112 , 113 ].…”

Effect of the C/N Ratio on Biodegradation of Ciprofloxacin and Denitrification from Low C/N Wastewater as Assessed by a Novel 3D-BER System

“…It was evident that the distribution of the main classes in these seven samples was significantly different. Nevertheless, the amount of Gammaproteobacteria present in sample S4 was more significant than that of any other samples compared to the distribution of Alphaproteobacteria, Bacteroidia, Deltaproteobacteria, Bacillus, Actinobacteria, and Clostridia [1,3,44]. The equivalent distributions of anaerobic sludge in the S1, S2, S3 and S5 samples were relatively low compared to for the samples S4, S6 and S7 from the 3D-BER system.…”

“…As shown in Figure 4 [19,20,40,44]. Under those conditions, the maximum removal efficiencies of NO 3 − -N, TN and CIP were found to be 35.66% to 95.55%, 13.93% to 80.27% and 12.59% to 94.20%, while the C/N ratio was between 0 to 1.5 and 2.5 to 3.5 at a electric current intensity of 60 mA, respectively [19,48,52].…”

“…When the ratio of C/N increased from 0 to 1. Figure 3h, TN average removal efficiency of 3D-BERS was 35.60% to 63.90%, 70.59% to 79.58%, 96.81% to 90.83% and 90.83% to 97.82% when the C/N went from 0 to 0.5, 1 to 1.5, 2.5 to 3.0 and 3.0 to 3.5, respectively (p < 0.05) [43,44]. In 3D-BERS, the average removal efficiency was respectively 96.81% and 97.82% when the C/N ratio was 1.5 and 3.5.…”

Bacterial Community Structure and Predicted Metabolic Function of Landfilled Municipal Solid Waste in China

“…For the slow degradation stage, the remaining organic matter from the previous stage is difficult to degrade [5]. Acceleration of the degradation process contributes to reducing the stock of waste as well as the pollution load [7][8][9]. Several methods, such as leachate recirculation, aeration, and the addition of exogenous microorganisms, have been proved to be effective in the acceleration of MSW degradation [7][8][9].…”