Bioconversion of olive-mill dry residue by Fusarium lateritium and subsequent impact on its phytotoxicity.
The present study investigated the ability of the non-pathogenic fungus Fusarium lateritium to either degrade or modify aromatic substances in olive-mill dry residue (DOR) and to reduce its phytotoxicity. The 80% reduction of ethylacetate extractable phenols in DOR colonized by the fungus for 20 weeks appeared to be due to polymerization reactions of phenol molecules as suggested by mass-balance ultrafiltration and size-exclusion chromatography experiments. Several lignin-modifying oxidases, including laccase, Mn-peroxidase and Mn-inhibited peroxidase were detected in F. lateritium solid-state cultures. Tests performed with tomato seedlings in soils containing 6% (w/w) sterilized non-inoculated DOR showed that the waste was highly phytotoxic. By contract, F. lateritium growth on DOR for 20 weeks led to a complete removal of the waste toxicity and to a higher shoot dry weight of tomato plants than that obtained in the absence of DOR.
Sampedro
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I
Dept. Microbiología, Estación Experimental del Zaidín, CSIC, Prof. Albareda 1, E-18008 Granada, Spain.
D'Annibale
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A
Ocampo
J A
JA
Stazi
S R
SR
García-Romera
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I
D000383:Agriculture; D001673:Biodegradation, Environmental; D019649:Food Industry; D005670:Fusarium / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D007220:Industrial Waste; D018551:Solanum lycopersicum / Q000254:growth & development*; D031658:Olea; D010636:Phenols / Q000032:analysis / Q000378:metabolism; D018517:Plant Roots / Q000254:growth & development; D018520:Plant Shoots / Q000254:growth & development; D014462:Ultrafiltration
D007220:Industrial Waste; D010636:Phenols