MICROORGANISMS ASSOCIATED WITH POSTHARVEST GREEN OLIVES DETERIORATIONS IN MOROCCO

Altered green olive fruits harvested by the pole slender method were studied for the microorganisms involved in post-harvest alterations of the fruits before the fermentation process. The determinations included: standard plate count, Gram-negative bacteria (coliforms and pseudomonads), Bacillus, and yeasts. Results showed that the alterations are due first to yeasts and their interactions with pseudomonads and coliforms. The most frequent yeasts were represented by the species: Debaryomyces hansenii, Rodothorula glutinis, Pichia membranefaciens, P. anomala and Candida bacarum. Gram-negative fermenting bacteria were represented by the species: Erwinia carotovora, Hafnia alvei, Enterobacter agglomerans, E. aerogenes and Serratia marcescens, S. liquefaciens and Shigella flexneri. The oxidase-positive bacteria were most abundant and mainly dominated by Pseudomonas species including P. aeruginosa, P. alcaligenes and P. syringae. Most of the isolates of these microorganisms were cellulolytic and lipolytic. Bacillus especies were also isolated and identified. The main species were Bacillus megaterium, B. pumilus, B. cereus and B. olei. Bacillus species seem not involved in olive deteriorations.