RESUMO
Com este trabalho, avaliou-se a produção de biopolímero sintetizado por Sphingomonas capsulata ATCC 14666, utilizando-se os meios industriais melaço bruto e pré-tratado e resíduo de proteína texturizada de soja (PTS). Foram testadas diferentes concentrações de meios industriais (2,66, 4, 6 e 8 por cento), cujas condições de fermentação utilizadas foram 28° ± 2°C, 208 rpm, 72 h. Os ensaios foram realizados em triplicata e os resultados foram avaliados estatisticamente mediante o teste de Tukey. As melhores produtividades foram obtidas para melaço pré-tratado 8 por cento (0,290 gL-1h-1), seguida de extrato aquoso de resíduo de PTS 6 por cento (0,240 gL-1h-1) e melaço bruto 8 por cento (0,190 gL-1h-1). A qualidade reológica das gomas foi demonstrada através da leitura de viscosidade aparente de soluções aquosas e salinas a 25 e 60°C.
This work studied the biopolymer production by Sphingomonas capsulata ATCC 14666 using industrial raw material and pretreated molasses and aqueous extract of textured soy protein (TSP). Different concentrations of industrial media (2.66, 4, 6 and 8 w/t percent) were evaluated at 28° ± 2°C, 208rpm, 72h, were the fermentation conditions utilized. Triplicate assays were conducted and Tukey's test was used. The highest productivity were obtained for 8 percent of pretreated molasses (0,290 gL-1h-1), 6 percent of aqueous extract of TSP (0,240 gL-1h-1) and 8 percent raw molasses (0,190 gL-1h-1), respectively. The rheological behavior of aqueous and saline (NaCl and CaCl2 3 percent wt/v) solutions of biopolymers were investigated by apparent viscosity analysis at 25 and 60°C.
RESUMO
This work was aimed at the production and rheological characterization of biopolymer by Sphingomonas capsulata ATCC 14666, using conventional and industrial media. The productivity reached the maximum of 0.038 g/L x h, at 208 rpm and 4% (w/v) of sucrose. For this condition, different concentrations of industrial medium were tested (2.66, 4, 6, and 8%). The best productivity was obtained using pretreated molasses 8% (w/v) (0.296 g/L x h), residue of textured soybean protein 6% (wt/v) (0.244 g/L x h) and crude molasses 8% (w/v) (0.192 g/L x h), respectively. Apparent viscosity presented similar results when compared with those in the literature for other biopolymers.