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The present study sought to explore the bioremediation of oil-based paint from aqueous media using indigenous bacterial isolate Brevibacillus parabrevis strain NAP3 and its toxicity assessment against prokaryotic and eukaryotic biological models. The bacterial isolate was initially screened for bioremediation potential in mineral salts medium containing oil-based paint (conc. 300 ppm, w/v) under shake flask settings. Moreover, the percentage removal of oil-based paint from aqueous media was investigated using a spectrophotometer at 285 nm under two different experimental conditions, i.e., with and without glucose. Evidently, the bacterial isolate displayed maximum oil-based paint removal of 83% in flasks containing glucose as an additional carbon source after 14 days of the treatment, whereas without glucose supplementation it reached up to 78%. The Fourier transform infrared (FTIR) spectra showed noticeable biodegradative changes of the oil-based paint relevant to peaks in the wave number frequency range of 800-600 cm , and 3,200 to 3,400 cm -1 (corresponding to C-H, C-O-N, C-O-C, and CH 2 aliphatic stretch and terminal CH 3 bonds, and N-H bonds, respectively, in treated samples as compared to controls; non-inoculated samples). After treatment, the cellfree supernatants containing oil-based paints displayed reduced cytotoxicity against brine shrimp larvae, phytotoxicity against wild reddish seeds, and antimicrobial activity against selected pathogenic bacteria and fungi, which indicated the possible use of B. parabrevis as potential oil-based paint-degrading bacterium in order to restore paint-polluted environments.

Environmental pollution by oil-based paint effluents is of great concern nowadays due to widespread applications of oil-based paints that cause discharge and accidental spillages into the environment. The present study sought to explore the potential use of indigenous bacterial isolates for biodegradation of oil-based paints. The oil-based-paint-biodegrading potential of three Bacillus species isolated from paint-polluted soil samples of different paint warehouses was investigated by the enumeration, screening and taxonomic characterization of oilbased-paint-degrading bacteria using soil enrichment technique in mineral salt medium (MSM). The screened isolates were identified based on morphological, biochemical and 16S rRNA gene sequence homology methods. The bioremediation potential of each bacterial isolate was determined for a period of 14 days at 37°C and 160 rpm in 250-ml shake flask containing 100 ml MSM plus oil paint (final conc. 300 ppm, w/v). The percent removal of oil-based paint was determined against a standard curve of oil-based paint prepared by using UV-Vis spectrophotometer at 285 nm (k Max.). Three bacterial isolates, Bacillus subtilis strain NAP1 (GenBank: KJ872852), B. subtilis strain NAP2 (GenBank: KJ872853) and B. subtilis strain NAP4 (GenBank: KJ872855) were isolated and identified. All the isolated strains were characterized as potential oil-based paint degraders. Maximum oil-based paint removal was recorded with strains NAP1 (66.5 %), followed by NAP2 (61.4 %) and NAP4 (55.9 %). The oil-based-paint-polluted environments are a promising source of oil-based-paint-degrading bacteria. The bacterial isolates of present study offer substantial potential for future environmental applications.