Biomass production and detoxification of wastewaters from the olive oil industry by strains of Penicillium isolated from wastewater disposal ponds

Olive mill wastewater (OMW) usually has to be diluted before biological tre atment. In the present work seven strains of Penicillium isolated from OMW disposal ponds were tested for biomass production and biodegradation of und iluted OMW. Best results were obtained by using strain P4, which formed 21. 50 g (dry weight) of biomass per litre of undiluted wastewater after 20 day s of cultivation. This and other strains also carried out an outstanding re duction of the chemical oxygen demand (COD) and the phenolic content of OMW , as well as a pH raise. The process could be accelerated by agitation. OMW fermented with Penicillium P4 was devoid of its initial antibacterial acti vity against Bacillus megaterium ATCC 25848. (C) 2000 Elsevier Science Ltd. All rights reserved.