Direct estimation of the oxygen requirements of Achromobacter xylosoxidans for aerobic degradation of monoaromatic hydrocarbons (BTEX) in a bioscrubber

The O₂ requirements for biomass production and supplying maintenance energy demands during the degradation of both benzene and ethylbenzene by Achromobacter xylosoxidans Y234 were measured using a newly proposed technique involving a bioscrubber. Using this approach, relevant microbial parameter estimates were directly and simultaneously obtained via linear regression of pseudo steady-state data. For benzene and ethylbenzene, the biomass yield on O₂, Y_X/O2, was estimated on a cell dry weight (CDW) basis as 1.96 ±.25 mg CDW mgO₂ and 0.98 ±.17 mg CDW mgO₂, while the specific rate of O₂ consumption for maintenance, m_O2, was estimated as 0.041 ±.008 mgO₂ mg CDW^h and 0.053 ±.022 mgO₂ mg CDW^h, respectively.