Effect of purified killer toxin extracted from Saccharomyces cerevisiae on some pathological microorganisms cause urinary tract infections

Abstract

Ecological killer yeasts have had fewer studies than laboratory killer yeasts. The killer yeasts are known for excreting killer toxins that kill susceptible microorganisms, such as killer toxin excreted by Saccharomyces cerevisiae. The sensitivity of the isolates was studied by bacterial exposure to several antibiotics after being diagnosed by cultural and biochemical methods, as well as by using the Vitek2 system to confirm the diagnosis of Gram-negative and Gram-positive bacteria; the most resistant isolates were selected in subsequent experiments. Purification steps included the use of (NH4)2SO4 78-70% saturated solution and Sephacryl G-150, giving one peak that was collected to give inhibition zones of 31, 28, 8.5, 85, 12, 24 mm diameter for E.coli, P.mirabilis, K.pneumoniae, P.aeruginosa, S.aureus, and C.albicans, respectively, with a 771.77% yield from the total protein 0.090 mg\ml of yeast crude extract. The well diffusion method was used to investigate the inhibitory activity of the purified toxin. The results showed that the inhibitory activity of purified toxin was increased after each purification step and differed in its effect according to the type of microorganisms and that the isolate of E. coli was the most sensitive in all experiments suffix. Keywords: Killer toxins, Yeasts, Thin layer chromatography, Purification, Antimicrobial activity.