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Lentinus edodes CCB-42 was immobilized in loofa sponges and applied to the biosorption of the synthetic dyes congo red, bordeaux red and methyl violet. Live immobilized microorganisms achieved average decolorations of congo red, bordeaux red and methyl violet of 97.8, 99.7 and 90.6 %, respectively. The loofa sponge was the support and the coadjuvant promoting dye adsorption. The biosorption conditions were optimized for each dye, yielding 30 °C, pH 5.0 and a 12 h reaction time for congo red; 25 °C, pH 3.0 and 36 h for bordeaux red; and 25 °C, pH 8.0 and 24 h for methyl violet. Operational stability was evaluated over five consecutive cycles, with both bordeaux red and congo red exhibiting decolorations above 90 %, while the decoloration of methyl violet decreased after the third cycle. In the sixth month of storage, congo red, bordeaux red and methyl violet had decolorations of 93.1, 79.4 and 73.8 %, respectively. Biosorption process best fit the pseudo-second-order kinetic and Freundlich isotherm models. Maximum biosorption capacity of heat-treated L. edodes immobilized in loofa sponge was determined as 143.678, 500.00 and 381.679 mg/g for congo red, bordeaux red and methyl violet, respectively. Treatment with immobilized L. edodes reduced the phytotoxicity of the medium containing dyes. FT-Raman experiments suggested the occurrence of interactions between loofa sponge fibers, L. edodes and dye. L. edodes CCB-42 immobilized in loofa sponges represents a promising new mode of treatment of industrial effluents.

ResumoIt is difficult to treat wastewater containing dyes and a wide variety of synthetic dyes have been applied in many industries. Bordeaux red is a synthetic dye used in food. In this study heat-inactivated Lentinus edodes CCB-42 was immobilized in loofa sponges and applied to the biosorption of bordeaux red, and toxicity bioassay of the dye-containing medium was taken before and after treatment. The biosorption conditions were optimized and it was possible to remove 80.8% of bordeaux red using heatinactivated L. edodes. Toxicity tests were performed to determine whether treatment with heat inactivated L. edodes reduced the toxicity of the dye solutions. Buffer solutions with 200 mg/l dye, called raw effluent, were tested along with the solution treated with inactivated and immobilized microorganism under ideal conditions, called treated effluent. Phytotoxicity tests were conducted using Lactuca sativa Aurelia seeds and raw and treated effluent samples were diluted to 1, 3, 10, 30 and 100% using hard reconstituted water. Acute ecotoxicity tests were performed according to the methodology of solution cultivation for hatching Artemia salina cysts and samples of raw and treated effluents were diluted to yield solutions with 20, 40, 60, 80 and 100% effluent. The percentage of germination was higher in more dilute samples, and no germination occurred in samples containing 100% wastewater. In all cases, the germination percentage of L. sativa seeds was higher in the treated effluent after biosorption by heat-

ResumoSuccinoglycan is a soluble exopolysaccharide synthesized by bacteria, composed of glucose monomers, galactose and succinic acid, connected by β-linkages. It is a thickening agent with broad potential application in the food, pharmaceutical and chemical industries. The objective of this research was to evaluate the production operational cycles of succinoglycan obtained from Agrobacterium radiobacter NBRC 12665 free and immobilized in loofa sponge (Luffa cylindrica), using the substrates lactose and sugar cane molasses. To produce succinoglycan, the microorganism was inoculated onto pre inoculum (g/L): sucrose (20), yeast extract (5) and peptone (5). After 72 h incubation, cells were transferred to production medium in erlenmeyer flasks containing 100 ml of medium varying the carbon source (g/L): lactose or sugar cane molasses (7.5) KH2PO4 (1), MgSO4 (0.25), (NH4) 2HPO4 (1), trace elements solution (10 mL), pH 7.0. The solution of trace elements in 100 mL of 0.1N HCl contained: FeSO4.7H2O (0.5 g), MnSO4.H20 (0.2), ZnCl2 (0.1), CoCl2.6H2O (0.1). The incubation in the production medium occurred for 8 days at 30 °C and 180 rpm. The operational cycles were evaluated based on 8-day cycles. At the end of each cycle, the free cells and loofa sponge containing immobilized cells were transferred to a new production medium. The