Application of detergent as carbon sources for polyhydroxyalkanoate accumulation by Bacillus spp.

This study investigated the potential of various detergents as carbon substrates for polyhydroxyalkanoate (PHA) production under nitrogen-limited conditions. We determined that Tween 80 promoted PHA accumulation by ZD-F1, a Bacillus sp. strain isolated from field sludge. When cultured with Tween 80, ZD-F1 achieved a peak dry cell weight (DCW) of 3.28 g/L, along with a PHA content of 18.96% and PHA yield of 0.48 g/L. Tween 80 at various concentrations resulted in a PHA theoretical yield of 0–10.6%. Experiments assessing the PHA species indicated that the PHA species under both Tween 80 and glucose was 3HB. Moreover, through chemical and biochemical stoichiometric calculations, we determined that the theoretical yields of 3HB from Tween 80 were 1.228 and 0.558 g/g, respectively, and those of 3HB from glucose were 0.716 and 0.318–0.477 g/g, respectively, across various catabolic pathways. To our knowledge, this is the first study to analyze PHA accumulation by a Bacillus sp. strain—isolated from wastewater treatment plant sludge—under various detergents as carbon sources.