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The waste materials from the carob processing industry are a potential resource for second-generation bioethanol production. These by-products are small carob kibbles with a high content of soluble sugars (45-50%). Batch and fed-batch Saccharomyces cerevisiae fermentations of high density sugar from carob pods were analyzed in terms of the kinetics of sugars consumption and ethanol inhibition. In all the batch runs, 90-95% of the total sugar was consumed and transformed into ethanol with a yield close to the theoretical maximum (0.47-0.50 g/g), and a final ethanol concentration of 100-110 g/l. In fed-batch runs, fresh carob extract was added when glucose had been consumed. This addition and the subsequent decrease of ethanol concentrations by dilution increased the final ethanol production up to 130 g/l. It seems that invertase activity and yeast tolerance to ethanol are the main factors to be controlled in carob fermentations. The efficiency of highly concentrated carob fermentation makes it a very promising process for use in a second-generation ethanol biorefinery. [ABSTRACT FROM AUTHOR]

Large-scale production has been the major obstacle to the success of many biopesticides. The spreading of microbial biocontrol agents against postharvest disease, as a safe and environmentally friendly alternative to synthetic fungicides, is quite dependent on their industrial mass production from low-cost raw materials. Considerable interest has been shown in using agricultural waste products and by-products from food industry as nitrogen and carbon sources. In this work, carob pulp aqueous extracts were used as carbon source in the production of the biocontrol agent Pantoea agglomerans PBC-1. Optimal sugar extraction was achieved at a solid/liquid ratio of 1:10 (w/v), at 25°C, for 1 h. Batch experiments were performed in shake flasks, at different concentrations and in stirred reactors at two initial inoculums concentrations, 10 and 10 cfu ml. The initial sugar concentration of 5 g l allowed rapid growth (0.16 h) and high biomass productivity (0.28 g l h) and was chosen as the value for use in stirred reactor experiments. After 22 and 32 h of fermentation the viable population reached was 3.2 × 10 and 6.2 × 10 cfu ml in the fermenter inoculated at 10 cfu ml and 2.7 × 10 and 6.7 × 10 cfu ml in the bioreactor inoculated at 10 cfu ml. A 78% reduction of the pathogen incidence was achieved with PBC-1 at 1 × 10 cfu ml, grown in medium with carob extracts, on artificially wounded apples stored after 7 days at 25°C against P. expansum. [ABSTRACT FROM AUTHOR]