Open AccessBioremoval of Acephate by biofilm-forming Enterobacter cloacae – VITDAJ8 in a vertical packed bed biofilm bioreactor
Author(s) -
Dipti Mayee Dash,
Ankita Itusha,
Jabez W. Osborne
Publication year - 2020
Publication title -
asia-pacific journal of molecular biology and biotechnology/asia pacific journal of molecular biology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.137
H-Index - 19
eISSN - 2521-9839
pISSN - 0128-7451
DOI - 10.35118/apjmbb.2020.028.4.06
Subject(s) - biosorption , enterobacter cloacae , biofilm , chemistry , chromatography , aqueous solution , bioreactor , effluent , adsorption , microbiology and biotechnology , bacteria , biology , environmental engineering , organic chemistry , biochemistry , environmental science , enterobacteriaceae , sorption , genetics , escherichia coli , gene
Organophosphorus (OP) pesticides are widely used due to their specific chemical properties and broad spectrum insecticidal activity. Accumulation of OP residues in various targeted and non-targeted environmental sites have increased the risk of biomagnifications thereby rendering serious threat to human health and the environment. Hence, the present study is primarily focused on the effective removal of Acephate (ACP) from aqueous solution. Bacteria isolated from the agricultural field and tannery effluent were screened based on their tolerance against two OP pesticides. The pesticide-resistant strains were further screened for biofilm formation and EPS production under ACP stress. Isolate VITDAJ8 exhibited highest pesticide tolerance against ACP, excellent biofilm formation and EPS production ability. Molecular characterization of VITDAJ8 by 16S rRNA gene sequencing revealed the isolate to be the closest neighbor of Enterobacter cloacae (Accession no. KP305912). A bench-scale vertical packed bed biofilm bioreactor was designed for the bioremoval of OP pesticides. Groundnut shells with a bed height of 10 cm were used as substrate with biofilm formed by VITDAJ8. The biosorption of ACP from the aqueous solution was monitored using UV-Vis spectrophotometer and HPLC and maximum ACP bioremoval up to 86% was achieved within 90 minutes of reaction time. Removal of ACP using groundnut shells without biofilm support was comparatively less efficient. The equilibrium adsorption study revealed the process to be the best fit for Langmuir isotherm modeling with maximum adsorption up to 235 mg L-1 and the kinetics of biosorption was found to be fitting well with the second-order kinetic model.