Solid State Fermentation Based Olive Pomace Using Streptomyces Strains: A Preliminary Study

This study represents a preliminary investigation aimed to assess the possibility to recycle and valorize olive pomace by solid state fermentation (SSF) using Streptomyces strains. The olive pomace was collected from an olive pressing factory (super press system) during the olive fruit pressing season. The study was carried out at IMBE, University Aix Marseille-France, between April 2013 and June 2013, and at LMA, University of Bejaia-Algeria in September 2013. Three Streptomyces strains designated S1M3I, S1M3II and S1M3III were cultured on solid state fermentation based olive pomace at 30°C for 10 days, and subsequently, the lignocellulolytic enzyme activities (xylanase, CMCase and laccase), the viability of the microorganisms and the pH of the resulting substrates, were determined. The fermented substrate pH values remained significantly stable (p ˂ 0.05) throughout the fermentation period for the three strains; they were fluctuated between 6.54 and 6.99. The viability of all Streptomyces strains studied, decreased significantly (p ˂ 0.05) during the first four days of incubation, to reach up 0 cfu/mL of viability and 0 U/g enzymatic activities (xylanase, CMCase and laccase activities) were recorded for the three strains. Streptomyces strains, under the experimental conditions (30°C, pH 7 and 75% of moisture), were unable to grow and produce lignocellulolytic enzymes in solid state fermentation based olive pomace due to the mycelial morphology and Streptomyces developmental cycle, no neglect, the environmental factors. These preliminary results suggest that SSF – Streptomyces system is not suitable for conversion of solid waste from olive processing industry and to produce lignocellulolytic enzymes.