Production of Polysaccharide by Rahnella aquatilis with Whey Feedstock

Authors M.E. Pintado, A.I.E. Pintado, and F.X. Malcata are affiliated with Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Rua Dr. António Bernardino de Almeida, P-4200 Porto, Portugal. Address inquiries to Dr. F.X. Malcata. ABSTRACT The rates were monitored on biomass increase, polysaccharide production and viscosity development of whey broth and a control synthetic broth during fermentation by Rahnella aquatilis and organic acids, lactose, peptides and free amino acids were measured. Growth curves were similar and characterized by maximum specific growth rates of 0.61 h21 for whey and 0.63 h21 for synthetic medium. The yields of polysaccharide were 0.59 g/glactose for the synthetic medium and 0.56 for whey. Small peptides (,4,000 Da) and most free amino acids in both fermentation media were consumed within 24h.