Utilization of vegetable oil in the production of clavulanic acid by Streptomyces clavuligerus ATCC 27064

Production of clavulanic acid (CA) by Streptomyces clavuligerus ATCC 27064 in shake-flask culture ( 28 degrees C, 250 rev min(-1)) was evaluated, with media containing different types and concentrations of edible vegetable oil. Firstly, four media based on those reported in the literature were examined. The medium containing soybean oil and starch as carbon and energy source gave the best production results. This medium, with the starch replaced by glycerol, and with various soybean oil concentrations ( 16, 23 and 30 g l(-1)) was utilized to further investigate CA production. Medium containing 23 g l(-1) led to the highest CA productivity ( 722 mg l(-1) in 120 h) and that one containing 30 g l(-1) gave the highest CA titre ( 753 mg l(-1) in 130 h). Also, substitution of corn and sunflower edible oils furnished similarly good results in terms of CA titre and productivity. It can be concluded that easily available vegetable oil is a very promising substrate for CA production, since it is converted slowly to glycerol and fatty acids, which are the main carbon and energy source for the microorganism.