Biodegradation of Bisphenol A by a Newly Isolated Bacillus megaterium Strain ISO-2 from a Polycarbonate Industrial Wastewater

A novel bacterium, Bacillus megaterium strain ISO-2, capable of the degradation of bisphenol A (BPA), was isolated from wastewater collected from a polycarbonate industry. The bacterium, which was grown on mineral salts medium supplemented with yeast extract, exhibited complete BPA removal from 5mgL(-1) BPA within 72h. BPA-degrading ability and bacterial growth, however, were inhibited at higher BPA concentrations. Gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) analysis revealed several intermediates during the BPA degradation process by B. megaterium strain ISO-2. These intermediates were identified as 4-(2-hydroxypropan-2-yl)phenol, 4-isopropylphenol, 4-isopropenylphenol, benzoic acid, butanoic acid, propanoic acid, benzeneacetic acid, phenylethyl alcohol, 4-hydroxy-3-methoxybenzaldehyde, and phenolic compounds. The possible degradation pathway of BPA was proposed. In addition, strain ISO-2 effectively removed BPA present in the wastewater and could also tolerate high total dissolved solids (TDS) and an alkaline environment. The results indicate that B. megaterium strain ISO-2 is a very effective bacterium for BPA removal from industrial or contaminated wastewaters.