Enhancing the effect of soybean oil refinery byproducts on erythromycin production by Saccharopolyspora erythraea

Erythromycin production is clearly enhanced by the addition of vegetable oils. However,whether this positive effect is brought about by the triglyceride or non-triglyceride fraction, isnot clear. The non-triglyceride portions of the oils accumulate in the waste during the refiningprocess leaving mainly triglycerides in the refined oil. In this research, sub-fractions of soybeanoil, including lecithin, soap stock, free fatty acid, deodorizer distillate and unsaponifiable matterwere supplemented by batch and fed-batch to chemically defined and complex fermentationmedia. The fermentation flasks were incubated at 30°C for 8 days at 220 rpm. It resulted in theproduction of low concentrations of oil by-products (1-5 g/l) at the beginning of fermentation,increased antibiotic production and had a greater enhancing effect than using crude oil.However, some fractions of oil such as free fatty acids considerably reduced antibioticproduction. The results of this study highlight the advantages of substitution of vegetable oilwith its refining by-products in the fermentation media.