TITLE:
Biodegradation of Toxic Compounds in Olive Mill Wastewater by a Newly Isolated Potent Strain: Aspergillus niger van Tieghem
AUTHORS:
Fatiha Hanafi, Mohammed Mountadar, Samira Etahiri, Mohamed Fekhaoui, Omar Assobhei
KEYWORDS:
Aspergillus niger van Tieghem; Olive Oil Mill Wastewaters; Phenolic Compounds; Tannase; Toxicity
JOURNAL NAME:
Journal of Water Resource and Protection,
Vol.5 No.8,
August
14,
2013
ABSTRACT:
Thirty-two strains isolated from olive oil production plants were screened
for their tolerance to the polyphenols and their ability to grow in olive oil
mill wastewaters (OMW). An Ascomycete isolate that grew best on OMW was
selected for further study to evaluate its effect on removal of organic
pollutants, phenolic compounds and OMW toxicity. This strain was identified by
DSMZ as Aspergillus niger van
Tieghem. The growth of Aspergillus niger van
Tieghem on stored OMW decreased pH and led to the reduction of phenolic
compounds with a resultant discoloration of OMW and significant reduction of
chemical oxygen demand (COD), in proportion to the dilution of OMW. The
reduction of the COD, phenolics and color exceeded 50%. Tannase, the enzyme
detected in the growth medium of Aspergillus
niger van Tieghem was produced during primary metabolic growth. The maximal
enzyme activity attaining 0.68 EU/ml was achieved in 3rd days of cultivation.
The phytotoxicity of the stored OMW was reduced to about 40% after 4 days’ incubation
with Aspergillus niger van Tieghem.