Bioremediation of Phenol and Hexavalent Chromium by using Acinetobacter baumannii B9

Abstract

The present thesis work explores the potential of isolated microbial strain(s) newlinefor bioremediation of co-contaminated system. In this study, phenol and Cr newline(VI) were chosen as model organic compound and heavy metal, respectively. Studies on newlinea newly isolated bacterial strain harboring novel properties of tolerating and removing newlinephenol and Cr (VI) individually as well as simultaneously from the wastewater makes the newlinecore of the thesis. newlineFor removal of organic compound and heavy metals from co-contaminated newlinesystem, there is a prerequisite of those microbial strain(s) that possess toxicants tolerance newlineabilities. Thus, the work was started with isolation of such novel microorganisms and newlineanalyzing their tolerance properties towards individual as well as simultaneous presence newlineof phenol and heavy metals. newlineA total of eleven phenol-tolerant bacterial strains (B1, B2, B3, B4, B5, B6, B7, newlineB8, B9, C1, and C2) could successfully be isolated from wastewater and contaminated newlinesoil. These isolates were further screened for their higher phenol and heavy metals [Cr newline(VI), Cu (II), and Ni (II)] tolerance and co-tolerance using plate assay methods. All the newlineeleven strains were able to grow in concurrent presence of lower phenol and heavy metals newlineconcentrations. Though growth of each of the microbial strains inhibited with increase in newlineconcentration of both phenol and heavy metals; strain B9 showed better visible growth in newlineco-presence of higher concentrations of phenol and heavy metals compared to other newlinestrains. newlineOverall, the entire work leads to isolation and identification of naturally occurring newlinephenol and heavy metal tolerant microbe(s) especially Acinetobacter baumannii B9, newlinewhich is able to decontaminate both phenol and hexavalent chromium in their single as newlinewell as simultaneous presence. Significant removal of three sets of contaminants viz. newlinephenol, Cr (VI), and phenol+Cr (VI) from complex effluent systems by Acinetobacter sp. newlineB9 strengthens the potentiality of the strain in industrial pollution control.