Effect of fermentation conditions on the production of hyaluronic acid by Streptococcus zooepidemicus ATCC 39920/Efeito das condicoes de fermentacao na producao de acido hialuronico por Streptococcus zooepidemicus ATCC 39920

The production of hyaluronic acid by Streptococcus zooepidemicus ATCC 39920 with varying rates of pH (6.0, 7.0, 8.0), temperature (34; 37; 40°C), agitation (100, 150, 200 rpm), glucose (10, 20, 30 g [L.sup.-1]) and yeast extract concentration (10, 20, 30 g [L.sup.-1]) was evaluated by statistical approaches. The best conditions for the production of hyaluronic acid was pH 8.0, 37°C and 100 rpm in a medium containing 30 g [L.sup.-1] glucose and yeast extract, for a production of 0.787 g [L.sup.-1]. Temperature, pH and yeast extract were significant variables (p < 0.05). Yeast extract and pH had a positive effect on the production of the polymer. Lactate, formate and acetate synthesis were also analyzed. Current assay showed the feasibility of statistical tools to optimize the physical and nutritional parameters for the production of hyaluronic acid and the improvement of the fermentation process. Keywords: physical factors, nutritional factors, glycosaminoglycans, factorial design, microbial production. A producao de acido hialuronico por Streptococcus zooepidemicus ATCC 39920 foi avaliada variando pH (6,0; 7,0, 8,0), temperatura (34; 37; 40°C), agitacao (100, 150, 200 rpm) e concentracao de glicose (10, 20, 30 g [L.sup.-1]) e extrato de levedura (10, 20, 30 g [L.sup.-1]) por metodologias estatisticas. A condicao otimizada foi pH 8,0, 37°C e 100 rpm, em meio contendo 30 g [L.sup.-1] de glicose e extrato de levedura atingindo a producao de 0,787 g [L.sup.-1]. O pH, temperatura e extrato de levedura foram as variaveis significativas (p < 0,05). Extrato de levedura e pH apresentaram efeito positivo para a producao do polimero. A sintese de acido latico, formico e acetico tambem foi analisada. Este estudo demonstra a viabilidade de utilizacao de ferramentas estatisticas para otimizar os parametros fisicos e nutricionais para a producao de acido hialuronico, permitindo a melhoria do processo fermentativo. Palavras-chave: fatores fisicos, fatores nutricionais, glicosaminoglicanos, delineamento fatorial, producao microbiana.