TRANSGENIC TOBACCO PLANTS EXPRESSING A FUNGAL LACCASE ARE ABLE TO REDUCE PHENOL CONTENT FROM OLIVE MILL WASTEWATERS

Abstract

A biotechnological approach was applied to reduce phenol content in olive mill wastewaters by transgenic tobacco plants. The cDNA laccase of poxC gene from Pleurotus ostreatus, carrying its own signal peptide for extracellular secretion, was transferred into the Nicotiana tabacum genome. Transgenic tobacco plants were obtained and the recombinant enzyme was secreted into the rhizosphere by the plant root apparatus, confirming the ability of the plant machinery to recognize the fungal POXC peptide signal leader appropriately as secretory tag. Total laccase activity assayed by ABTS in transgenic lines increased sharply compared to control plants. Moreover, plants cultivated in a hydroponic solution with the addition of olive mill wastewaters were able to reduce the total phenol content up to 70%.

^†equal contribution of these authors

KEY WORDS::

• phytoremediation
• Pleurotus ostreatus
• laccase
• Nicotiana tabacum
• metabolic engineering
• olive oil mill wastewaters

ACKNOWLEDGMENTS

The authors wish to thank Sara Siervo for her valuable help in plant tissue culture, Rosario Nocerino for his technical assistance and Prof. Giovanni Sannia for providing the poxC cDNA and the antibodies.

Notes

^†equal contribution of these authors