This study was aimed at evaluating the microbiological quality of mangrove oysters (Crassostrea rhizophorae), collected at a natural oyster bed in the estuary of Cocó river (Fortaleza, Ceará, Brazil). MPN values were used for estimating the total (TC) and fecal (FC) coliforms and Enterococcus spp. TC and FC MPN values in the whole muscle and intervalve liquid ranged from <1.8 to >1,600/g and from <1.8 to 920/g, respectively. The MPN estimates for Enterococcus spp. were between <3.0 and >1,100/g. No correlation was found between the physico-chemical parameters (temperature, salinity and pH) of the surrounding water and the bacteriological contamination levels found in the tested oysters. The only correlation found was between TC and FC values. Enterococcus spp. strains were isolated and subjected to biochemical tests for species identification. The capacity of those strains for production of a bacteriocin-like inhibitory substance was tested using the Escherichia coli strain ATCC 25922 as a testing organism. Only one, E. faecalis, out of 121 Enterococcus strains tested, presented the inhibitory activity.

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SUMMARYBetween April and October 2002, thirty fortnightly collections of oysters (Crassostrea rhizophorea) from a natural oyster bed at the Cocó River estuary in the Sabiaguaba region (Fortaleza, Ceará, Brazil) were carried out, aiming to isolate Aeromonas spp. strains. Oyster samples were submitted to the direct plating (DP) and the presence/absence (P/A) methods. Aeromonas were identified in 15 (50%) samples analyzed by the DP method and in 13 (43%) analyzed by the P/A method. A. caviae, A. eucrenophila, A. media, A. sobria, A. trota, A. veronii bv. sobria, A. veronii bv. veronii and Aeromonas sp. were isolated. The predominant species was A. veronii (both biovars), which was identified in 13 (43%) samples, followed by A. media in 11 (37%) and A. caviae in seven (23%). From the 59 strains identified, 28 (48%) presented resistance to at least one of the eight antibiotics tested.

Desalination concentrate (DC) is a potential medium for microalgal cultivation since it contains an abundance of mineral salts. In this study, the feasibility of growing Chlorella vulgaris with DC was evaluated and the influence of DC concentration on the growth, biomass productivity, and biochemical composition was assessed. Media comprised of DC mixed with bold basal medium (BBM) in different concentrations were prepared for microalga cultivation. A sequential statistical methodology, comprising fractional factorial design and response surface methodology (RSM) was applied to enhance the biomass production. The growth of C. vulgaris was promoted with 75 % BBM+25 % DC compared with the BBM control. C. vulgaris biomass production (0.59 g L −1 ) was observed with 75 % BBM+25 % DC with optimal concentrations of sodium nitrate (0.09 g L −1 ), monobasic potassium phosphate (0.014 g L −1 ), and micronutrient solution (0.20 mL L −1 ). The gradual increase of DC had a strong effect on the biochemical composition of C. vulgaris. Carbohydrate fiber and protein contents were estimated to be 14.4 and 51.3 %, respectively, when the microalgae were cultivated in 75 % BBM +25 % DC. The lipid content (12.5 %) of C. vulgaris cells was highest at the optimized BBM DC concentrations. When grown in the BBM control and optimized BBM+DC media, C. vulgaris produced lipids rich in polyunsaturated fatty acids (C18:3 ω3) and monounsaturated fatty acids (C18:1). These results indicated that DC is a feasible alternative for the mass cultivation of C. vulgaris.

Utilizou-se mel de abelhas (Apis melifera) para a obtenção de vinagre, com a perspectiva de diversificação dos produtos derivados do mel. O mosto foi preparado com mel diluído em água destilada, resultando numa solução com 21 Brix, enriquecida com sulfato de amônio e fosfato de amônio e inoculada com fermento comercial desidratado (Saccharomyces cerevisiae) numa proporção de 4 g/L. A fermentação alcoólica ocorreu em temperatura ambiente, durante 24 horas. Um kilograma de mel rendeu cinco litros de hidromel com teor alcoólico em torno de 8% (v/v), a partir de mosto com 17,11% (p/v) de açúcares totais. A eficiência da fermentação alcoólica foi de 81,34%. A fermentação acética foi realizada pelo método rápido, em fermentador vertical com capacidade de 15 litros. O vinagre obtido apresentou acidez em torno de 9% e teor alcoólico residual em torno de 1% (v/v). O rendimento da fermentação acética ficou entre 91,24 e 97,21%. A avaliação sensorial revelou índices de aceitação acima de 70%, ou seja, 95,37% para a aparência; 94,81% para cor; 79,07% para odor e 75,56% para sabor. Abstract It was utilized bee honey (Apis mellifera) for vinegar obtention, with the perspective of honey derived products diversification. The wort was prepared by diluting honey in distilled water to 21% total solids and by adding ammonium sulfate and ammonium phosphate. Saccharomyces cerevisiae was inoculated to the wort (4 g/L). Alcoholic fermentation was carried out at room temperature during 24 hours. In this study, 1 Kg of honey yielded about 5 L of wine, containing about 8% alcohol (v/v), from a wort with 17.11% total sugars (w/v). The efficiency of the alcoholic fermentation was 81.34%. The acetic fermentation was performed by quick process in a 15 L vertical fermenter. This resulted in a vinegar containing up to 9% of acetic acid (w/v) and about 1% of alcohol (v/v). The acetic fermentation yielded between 91.24 and 97.21%. Approximately 5 L of honey vinegar with 9% acetic acid (w/v) were obtained from 1 Kg of bee honey. All attributes of honey vinegar showed acceptability index over 70%: 95.37% for appearence, 94.81% for colour, 79.07% for odour and 75.56% for flavour, indicating it would show good consumer acceptability.