Biomineralization and formulation of endosulfan degrading bacterial and fungal consortiums

•Biodegradation of endosulfan and its metabolites are reported.•Degradation processes were studied by HPLC and FTIR analyses.•Endosulfan sulfate was converted to non-recoverable acidic forms.•Low cost solid materials were used for the formulation of microbial consortium. Microbial degradation offers an effective approach to remove toxicants and in this study, a microbial consortium consisting of bacterial strains and fungal strains were originally obtained from endosulfan contaminated agricultural soils. Identification of the bacterial isolates by 16S rRNA sequences revealed the isolates to be Halophilic bacterium JAS4, Klebsiella pneumoniae JAS8, Enterobacter asburiae JAS5, and Enterobacter cloacae JAS7, whereas the fungal isolates were identified by 18S rRNA sequences and the isolates were Botryosphaeria laricina JAS6, Aspergillus tamarii JAS9 and Lasiodiplodia sp. JAS12. The biodegradation of endosulfan was monitored by using HPLC and FTIR analysis. The bacterial and fungal consortium could degrade 1000 mg l−1 of endosulfan efficiently in aqueous medium and in soil. The infrared spectrum of endosulfan degraded samples in the aqueous medium by bacterial and fungal consortium showed bands at 1400 and 950 cm−1 which are the characteristics of COOH group and acid dimer band respectively. In the present investigation, low cost solid materials such as sawdust, soil, fly ash, molasses and nutrients were used for the formulation of microbial consortium and to achieve greater multiplication and survival of the microbial strains.