Detoxification of olive mill wastewaters by Moroccan yeast isolates
A total of 105 yeast strains were isolated from Moroccan olive oil production plants and evaluated for their ability to grow in olive oil mill wastewaters (OMW). The 9 isolates that grew best on OMW were selected for further study to evaluate their effect on removal of organic pollutants and OMW phytotoxicity (barley seed germination test). The results showed that at least four yeast isolates effectively lowered the toxicity of this effluent in addition to providing very useful materials in terms of both yeast biomass (6 g/l DW) and an irrigation fluid. This group of yeast isolates significantly reduced the concentration of total phenols (44% removal) and Chemical Oxygen Demand, COD (63% removal). The best germination rate of 80% for undiluted OMW was obtained for strain Candida holstii that also increased the pH from 4.76 to 6.75. Principal component analysis of the results obtained for the best yeast strains confirmed the importance of COD and total phenol reduction along with increase of organic nitrogen and final pH for the improvement of germination rates and phytotoxic reduction. This study has highlighted the potential of indigenous yeasts in detoxification of olive mill wastewaters.
KeywordsCarbohydrate assimilation COD Detoxification Germination assays Olive oil mill wastewaters Total phenols Yeasts
This project was supported in part by the Moroccan National Programme of Scientific Research: PROTARS II—P21/34.
- Aggelis G, Iconomoub D, Christouc M, Bokasa D, Kotzailiasa S, Christoua G, Tsagoua V, Papanikolaou S (2003) Phenolic removal in a model olive oil mill wastewater using Pleurotus ostreatus in bioreactor cultures and biological evaluation of the process. Water Res 36:4735–4744Google Scholar
- APHA, AWWA, WEF (1998) Standard methods for the examination of water and wastewater. In: Leonor S, Clesceri WEF, Arnold E, Greenburg APHA, Andrew D (eds) Eaton AWWA. 20th Ed. 1998. Washington, DC, USAGoogle Scholar
- Ben Sassi A, Boularbah A, Jaouad A, Walker G, Boussaid A (2005) A comparison of Olive oil Mill Wastewaters (OMW) from three different processes in Morocco. Process Biochemistry. Article in press. Available online 26 September 2005Google Scholar
- Garcia Garcia I, Jiménez Pena P, Bonilla R, Venceslada JL, Martin Martin A, Martin Santos MA, Ramos Gomez E (2000) Removal of phenol compounds from olive mill wastewater using Phanerochaete chrysosporium, Aspergillus niger, Aspergillus terreus and Geotrichum candidum. Process Biochemistry 35:751–758CrossRefGoogle Scholar
- Kim JK, Shoda M (1999) Purification and characterisation of a novel peroxidase from Geotrichum candidum Dec 1 involved in decolorization of dyes. Appl Environ Microbiol 65:1029–1035Google Scholar
- Papadopoulou A, Frazier R (2004) Characterization of protein-polyphenol interactions. Trends Food Sci Technol, vol 15, Issues 3–4, March–April 2004, 186–190Google Scholar
- Perez J, de la Rubia T, Hamman OB, Martinez J (1998) Phanerochaete flavido-alba laccase induction and modification of manganese peroxidase isoenzyme pattern in decolorized olive oil mill wastewaters. Appl Environ Microbiol 64:2726–2729Google Scholar
- Ramos-Cormenzana A, Monteoliva-Sanchez M, Lopez J (1995) Bioremediation of alpechin. Int Biodeterioration Biodegradation 249–268Google Scholar
- Salvemini F (1985) Composizione chemica e valutazione biologica di un mangime ottenuto essiccando tercamente le acque di vegitazione delle olive. Rev. Delle Sostanze grasse 112:559–564Google Scholar
- Shivarova N, Zlateva P, Atanasov B, Christov A, Peneva N, Guerginova M, Alexieva Z (1999) Phenol utilization by filamentous yeast Trichosporon cutaneum. Bioprocess Eng 20:325–328Google Scholar