Aim: To identify the source of bisphenol A (BPA) [2,2'-bis(4-hydroxyphenyl) propane] in cultures of an antibiotic-producing Bacillus sp. strain grown in polycarbonate flasks.
Methods and Results: Although a culture of an antibiotic-producing Bacillus sp. strain grown in a new, rinsed polycarbonate flask yielded BPA, duplicate cultures grown in thoroughly washed polycarbonate flasks did not. Cells of Escherichia coli strain C were grown in new polycarbonate flasks rinsed three-times with 100 ml distilled H(2)O. BPA was only recovered from cultures grown in new polycarbonate flasks, but not from the autoclaved medium incubated in parallel.
Conclusions: BPA was present in either Bacillus or E. coli cultures, probably due to its release from inadequately washed polycarbonate flasks. Standard autoclaving did not result in BPA appearance; microbial growth was required. Polycarbonate vessels for microbial cultures should be thoroughly washed to avoid the appearance of BPA in culture medium.
Significance and Impact of the Study: This study rigorously demonstrates that the presence of BPA in culture medium was a consequence of microbial growth or metabolism in inadequately washed polycarbonate flasks. As BPA exhibits antimicrobial and oestrogenic activity, searches for novel drugs or production of recombinant chemotherapeutic agents could be derailed by the artefactual appearance of BPA