2.7. Metabolite preparation
Suspension bacterial cell cultures at stationary phase (18 h incubation
at 37 C) were centrifuged at 10,000 g for 7 min. The pH
adjusted (7.4) supernatant was then sterilized using 0.22 mm filter
(Milipore, USA) [36]. Filtrates were applied to anti-proliferative or
cytotoxicity assessments.