Abstract

Methylomicrobium alcaliphilum, a halotolerant obligate methanotroph bacterium with novel biotechnology potential, was evaluated for use in biological reactors purposed for oxidizing anthropogenic methane emissions from municipal landfills. Design parameters included growth rate (μ=0.13 h-1), biomass yield on methane substrate (Yx/s=1.19gDCW/gCH₄±0.02), apparent yield on substrate (Yx/s=0.49gDCW/gCH₄±0.03), and specific methane degradation rate (qCH₄=0.13-0.26gCH₄/gDCW-h). Using these biokinetic constants for the marine bacterium and the U.S. EPA LandGEM tool to generate emission predictions for applications to the new North Valley Landfill in Utah, U.S.A., an engineered biological reactor for treatment of methane emissions was designed. A total of 250kg of M. alcaliphilum was required for treatment of 800,000 cubic meters of methane emitted from 280,000Mg of municipal landfill waste within stirred reactors at a continuous flow of 6,500L/hr sized at a total liquid phase volume of 50,000L. The applied research and testing demonstrated the potential to utilize M. alcaliphilum for mitigation of greenhouse gas emissions of methane from municipal landfills, which has been demonstrated in the literature to produce the high value bioproduct ectoine.

Keywords:Methanotrophs; Methane; Landfills; M. alcaliphilum