Olive mill wastewater triggered changes in physiology and nutritional quality of tomato (Lycopersicon esculentum mill) depending on growth substrate.

We have studied the changes in the physiology and nutritional quality of Lycopersicon esculentum exposed to olive mill wastewater (OMW) with regard to cultivation in sand and soil. Tomato plant performance decreased with increasing concentration of OMW to both substrates. Root was more sensitive to OMW than the upper parts of the plants, grown either in sand or in soil for 10 days and 3 months, respectively, probably due to the direct OMW toxicity on roots as compared to other parts. Significant restriction on uptake and translocation of nutrients (K, Na, Fe, Ca and Mg) under OMW application was found. The decrease in the photochemical efficiency of PSII photochemistry in the light adapted state and the big decrease in photochemical quenching, indicate that OMW resulted in diminished reoxidation of Q(A)(-) and started to inactivate the reaction centers of PSII. The OMW supply on soil and sand, resulted in leaf water stress and lesser water use efficiency. Plants treated with high OMW concentration, produced fewer but bigger tomatoes as compared to plants treated with lower OMW concentration. Generally, fruit yield and nutritional value was inhibited under OMW application.

Characterization of the microbial flora from a traditional Greek fermented sausage.

The microbial flora of naturally fermented sausages was studied. Lactic acid bacteria were the dominant species at the end of fermentation in all 3 batches (ca. 10(8) cfu g(-1)). Enterobacteria, Pseudomonas, yeasts and aerobic spore-formers decreased during fermentation and the ripening process and were below the detection limit in the end product. Enterococci exceeded 10(4)-10(5) cfu g(-1) during fermentation and remained constant at this level during ripening. Gram-positive, catalase-positive cocci exceeded 10(5) cfu g(-1), except for batch 1, during the first days of fermentation and then decreased until the end of ripening (10(2)-10(4) cfu g(-1)). No pathogenic staphylococci, sulfite reducing clostridia or Salmonella spp. were detected. Listeria spp. occurred in the first days of fermentation but were eliminated by the end of whole process in all batches. Identification showed that the majority of lactobacilli isolated from MRS agar strains were assigned to the species of Lactobacillus plantarum and Lb. plantarum/pentosus. All the isolated strains from the mannitol salt agar belonged to the genus of Staphylococcus. The predominant species were Staphylococcus saprophyticus, Staphylococcus xylosus and Staphylococcus simulans. The tests used to characterize the lactic acid bacteria and staphylococci as well as their distribution on the three batches were also discussed.