PRODUCTION OF CITRIC-ACID BY CANDIDA-LIPOLYTICA-Y1095 - EFFECT OF GLUCOSE-CONCENTRATION ON YIELD AND PRODUCTIVITY

The effects of temperature and initial pH on growth of Candida guillie rmondii Y 488, Candida lipolytica Y 1095, Yarrowia lipolytica Y 7576, and Saccharomycopsis lipolytica DRL 99 were evaluated. All four yeasts exhibited maximum biomass production at 27-degrees-C. Except for S. l ipolytica DRL 99, increased agitation nearly doubled the amount of bio mass produced at 27-degrees-C. The growth of S. lipolytica DRL 99 was also affected by initial medium pH. Based on the results of these expe riments, C. lipolytica Y 1095 was selected for citric acid production studies in a 2-l batch fermentor. At a glucose concentration of 3% w/v , the maximum specific growth rate of C. lipolytica Y 1095 was 0.38 h- 1. During the production phase, citric acid yields ranged from 0.50 to 0.79 g citric acid produced per gram glucose consumed and the volumet ric productivity ranged from 0.27 to 0.60 g citric acid per liter per hour. Final citric acid concentrations ranged from 13.6 to 78.5 g citr ic acid per liter and were dependent on the initial glucose concentrat ion in the production medium.