Production, separation, and antimicrobial activity assessment of pristinamycin produced using date fruit extract as substrate

Date fruits extract was assessed as substrate for pristinamycin production in shake flasks using Streptomyces pristinaespiralis DSMZ 40338 as production organism. A process of microfiltration, concentration, and solvent extraction was used to recover the antibiotic from the fermentation broth and its antimicrobial activity was tested using a well assay method. During a fermentation period of 120 h, the bacterium consumed approximately 28.4 g/l sugars, grew from 0.4 g/l to 4.0 g/l dry weight, and produced 51.0 mg/L pristinamycin. The microfiltration, concentration, and ethyl acetate solvent extraction applied resulted in 71% pristinamycin recovery. The antibiotic showed inhibition capacity comparable to that of the pristinamycins IA and IIA standards. The inhibited bacteria were Staphylococcus aureus, Escherichia coli, and Enterococcus faecium. Clear inhibition zones of 13.3–19.6 mm diameter were formed.