Extractive fermentation of clavulanic acid by Streptomyces DAUFPE 3060 using aqueous two-phase system

The influence of four variables, specifically polyethylene glycol (PEG) molar mass (400, 1,000, and 8,000 g/mol), concentrations of PEG and phosphate salts (15, 20, and 25% for both), and agitation intensity (110, 150, and 200 rpm), on clavulanic acid extraction by extractive fermentation with PEG/phosphate salts aqueous two-phase system was investigated in shaken flasks using a 2^4-1-fractional factorial design