Metagenomics Study of the Microbes in Constructed Wetland System Treating Sewage

Abstract

Constructed wetlands are ecofriendly, cost effective technology involved in treatment of wastewaters. The goal of this study is focused on characterization of microbial community existing in constructed wetland system planted withCyperusalternifoliustreating sewage contaminated with heavy metals. The characteristics of effluent met the standards of discharge for inland use and irrigation. Microbes in constructed wetland apparently play a pivotal role in the efficiency of system for removal of organics, nutrients, suspended solids and heavy metal. To expose the active players in the lime light, a representative soil sample from the reed bed was collected and characterized for microbial community analysis. Metagenomic studies of the bacterial and fungal flora were identified. Results revealed that the phylum Proteobacteria (38.27%) and Ascomycota (77.47%) dominated in the bacterial and fungal kingdom respectively. However, in the bacterial kingdom at species level major portion remain unclassified exceptPseudomonasalcaligenesbut in the fungal kingdom at species level only 3.1% remain unclassified. The role of bacteria in wastewater treatment is exemplified in previous reports but the role of fungi in wastewater system needs exploration. However, the findings reveal that the identified microbes might have definitely played a vital role in wastewater treatment. The database available for the identification of bacterial species remain undiscovered for a major portion and requires up gradation. Next generation sequence being a high end technology in microbial ecology decodes the entire community in environmental samples but lack of database limits the identification. Implementation of improvements in the paucity of data bases is essential.

Global Trends of Benthic Bacterial Diversity and Community Composition Along Organic Enrichment Gradients of Salmon Farms

“…Rhodospirillaceae as characteristic family of low impact sites under study are inhibited by high sulfide concentrations ( van Niel, 1944 ; Pfennig, 1967 ). Pirellulaceae react sensitively to lower pH values, as are typical of near-field sites ( Usharani, 2019 ), and Planctomycetaceae dislike eutrophic conditions that can be found in closer vicinity to salmon cages ( Li et al, 2017 ). Accordingly, these bacterial taxon groups are common members of natural benthic bacterial communities ( Lanzen et al, 2020 ).…”

Table_2.XLSX

“…Comamonadaceae (member of the Burkholderiales order in Betaproteobacteria) was the most dominant group in pond and treated effluent samples from Pond Inlet and was in the dbRDA related to removal of nutrients (CBOD 5 ). This family of bacteria has previously been reported to be involved in the biological nutrient removal processes, especially carbon and nitrogen containing compounds when the oxygen supply was limited (Sato et al, 2016;Usharani, 2019) as was the case in the present study. At the genus-level, Rhodoferax spp.…”

Characterization of the Spatial Variation of Microbial Communities in a Decentralized Subtropical Wastewater Treatment Plant Using Passive Methods

“…The phyla Gemmatimonadetes and Nitrospirae were only found in the HFCW, where higher levels of nitrogen and phosphate removal occurs. In consequence, previous studies have linked Gemmatimonadetes to nitrogen [54] and phosphate removal [50]. In this study, the phylum Gemmatimonadetes was only present at a depth of 10 cm in the HFCW and was completely absent in the first units (ST and UAF).…”

“…Proteobacteria was the most abundant phylum in all the system stages and gradually increased in abundance from one treatment stage to the next (ST < UAF < HFCW), with abundances of 34% in the ST, 38% in the UAF, and 60% in the HFCW (Figure 4a; Table S2). The members of this phylum are involved in a variety of metabolic pathways related to the carbon and nitrogen cycles [48][49][50], which explains their dominance in the whole WWTP. Additionally, Proteobacteria are known to be enhanced by the presence of macrophytes in CWS [51], which explains why their highest relative abundance was in the HFCW and which may also be associated with the high nitrogen mass reduction accomplished in this unit (Figure 3).…”

“…The family Rhodospirillaceae displayed an increasing trend from the inlet to the outlet of the HFCW (Table S9) and was more abundant at a depth of 10 cm than at 50 cm (Figures 5c and 6c). This sulfur oxidizing bacteria is capable of degrading organic compounds under anaerobic conditions and can act as a chemotroph under aerobic conditions [50]. However, Meyer et al [68] reported a higher abundance of the family Rhodospirillaceae (16%) in environments with higher oxygen concentrations during wastewater treatment.…”