EFFECT OF FERMENTATION PERFORMANCE ON THE ECONOMICS OF POLY(3-HYDROXYBUTYRATE) PRODUCTION BY ALCALIGENES LATUS

The effects of fermentation performance on the final production cost o f poly(3-hydroxybutyrate) [P(3HB)] were examined. Two processes for th e production of P(3HB) by Alcaligenes latus from sucrose with the reco very method of surfactant-hypochlorite digestion were designed and sub sequently analysed. The actual fermentation results that were differen t in the final P(3HB) content, P(3HB) yield and P(3HB) productivity we re used in the simulations. The production cost of P(3HB) was signific antly lower with higher P(3HB) content due to the reduction in polymer recovery cost. The cost of raw materials (mainly sucrose) was also lo wer with higher P(3HB) content since the process yielding higher P(3HB ) content also resulted in higher P(3HB) yield on carbon source. The d irect fixed capital-dependent costs decreased with increasing producti vity. By employing the fermentation process that resulted in high P(3H B) concentration, P(3HB) content and P(3HB) productivity of 98.7 g/l, 88.3% and 4.94 g P(3HB)/l/h, respectively, the final production cost o f P(3HB) was as low as US $2.6/kg P(3HB). (C) 1998 Elsevier Science Li mited. All rights reserved.