Isolation and identification of bacteria from rotary drum compost of water hyacinth

Purpose The present work aims to isolate and identifybacterial community from the rotary drum compost ofgreen waste such as the water hyacinth. Compost qualitywas also investigated with the physicochemical parametersand the heavy metal analysis.Methods For rotary drum composting, a waste mixture of150 kg with water hyacinth, cow dung and sawdust wereprepared in the proportion of 6:3:1, respectively. Thephysicochemical parameters such as pH, temperature,volatile solids and the electrical conductivity were analyzedto detect the compost quality. Pb, Ni, Zn, and Cdwere investigated for total heavy metals, toxicity characteristicleaching procedure (TCLP), diethylenetriaminepentaaceticacid (DTPA) and water solubility tests.Consistent and active bacterial community were isolatedfrom the rotary drum compost of water hyacinth. Culturedependentand culture-independent techniques wereapproached for the isolation process.Results Twelve bacteria were isolated and identified by16S rDNA sequencing and phylogenetic analysis; theymajorly belonged to the Bacillus and Enterobacter family.The analysis of temperature, pH, EC, VS and heavy metalsdepicted the good quality of compost. Heavy metals concentrationwas in Pb[Ni[Zn[Cd; however, for Pb,Cd and Ni water solubility remained non-detectable, DTPAconcentration for Pb and Cd was also found to be nondetectable.Conclusions The microbes in water hyacinth compost aremetabolically active degrading the organic matter, survivingin the heavy metal-loaded compost environment. Thus,green waste (water hyacinth) can be utilized to isolatebacterial species in anticipation of their application inheavy metal removal in liquid and solid waste sources formicro-bioremediation.