FK228 Many BPA degrading bacterial strains have

Many BPA-degrading bacterial strains have been isolated from soils, sludge, river and seawater [25] and [37]. These bacterial strains, capable of growing also on BPA as a sole source of carbon, included either gram-negative (Sphingomonas sp., Pseudomonas sp., Achromobacter sp., Novosphingobium sp., Nitrosomonas sp., Serratia sp., Bordetella sp., Alcaligenes sp., Pandoraea sp., Klebsiella sp.) or gram positive strains (Streptomyces sp., Bacillus sp.). An interesting review on bacterial mediated BPA degradation and on the mechanisms underlying its biochemical transformation has been recently published by Zhang et al. [37]. BPA removal has also been carried out using activated carbon (AC) [38]. AC is known to adsorb [39] FK228 compounds, including BPA, and is extensively used for the removal of contaminants in water or gas treatment systems. However, the major drawback of AC is that regeneration is needed when its adsorption capacity is exhausted. Regeneration results in an increase in the total cost of the system. The removal rate of a pollutant by coupling its biotransformation by bacterial microorganisms and its adsorption on activate carbon is known as biological activated carbon (BAC) process [40]. It has been shown that the mechanism of the BAC process is based on the combination of biodegradation and carbon adsorption. This synergism leads to the biological regeneration (bioregeneration) of the adsorbents and to the protection of microbial biofilm immobilized onto the AC. In this way by combining the adsorption property of AC with the microbial removal of BPA, the lifetime of AC can be extended; thus, the construction of a more efficient treatment system can be achieved. Another technique to remove BPA is that of its sorption and degradation by aerobic activated sludge, i.e. using 'FK228' air and a biological floc composed of bacteria and protozoa [41] and [42].