Fate of β-hexachlorocyclohexane in the mixed microbial cultures (MMCs) three-stage polyhydroxyalkanoates (PHA) production process from cheese whey

This work aimed to study the fate and effect of beta-hexachlorocyclohexane (beta-HCH) during several steps of PHA production and purification, by using an artificially contaminated cheese whey (CW) as the feedstock. Most of beta-HCH (around 90%) was adsorbed on CW solids and it was removed after the acidogenic fermentation step, when residual CW solids are separated along with anaerobic biomass from the liquid-phase. Purification steps also contributed strongly to the removal of residual beta-HCH; overall, the PHA production process removed about 99.9% of initial beta-HCH content. Moreover, it has been shown that beta-HCH has neither detrimental effect on acidogenic fermentation nor on PHA accumulation, that were performed by using unacclimated mixed microbial cultures. (C) 2015 Elsevier Ltd. All rights reserved.