|Whole-cell biocatalysis using the Acidovorax sp. CHX100 Δ6HX for the production of ω-hydroxycarboxylic acids from cycloalkanes
|Salamanca, D.; Bühler, K.; Engesser, K.-H.; Schmid, A.; Karande, R.
|Whole-cell biocatalysis; Acidovorax strain; ω-hydroxycarboxylic acids; cyclohexane oxidation
|Omega hydroxycarboxylic acids (ω-HAs) possess two functional groups, a hydroxyl group and a carboxyl group, and are essential precursors for the production of biodegradable polyester polymers. In this work, an Acidovorax mutant was investigated as a whole-cell biocatalyst for the conversion of cycloalkanes to their respective ω-hydroxycarboxylic acids. This Acidovorax sp. strain CHX100 originated from a wastewater treatment plant and uses cyclohexane as the sole source of carbon and energy with excellent growth rates (0.199 h-1). The metabolic efficiency of Acidovorax CHX100 is based on a highly efficient enzyme cascade used for the mineralization of cyclohexane. A deletion of 6-hydroxyhexanoate dehydrogenase in the native cycloalkane pathway resulted in the Acidovorax sp. strain CHX100 Δ6HX mutant, which accumulated short ω-hydroxycarboxylic acids (C5 to C10) from cycloalkanes. This mutant transformed cyclopentane and cyclohexane (5 mM) to 5-hydroxypentanoic acid and 6-hydroxyhexanoic acid, respectively, with a molar conversion above 98% in 6 h. An elementary environmental and economical assessment based on E-factor and biocatalyst yield suggests the use of inexpensive electron donor and carbon sources, with subsequent efforts to minimize waste generation. Such an early-stage analysis highlights the main bottlenecks that need to be solved in developing a sustainable bioprocess.
|Persistent UFZ Identifier
|Salamanca, D., Bühler, K., Engesser, K.-H., Schmid, A., Karande, R. (2021):
Whole-cell biocatalysis using the Acidovorax sp. CHX100 Δ6HX for the production of ω-hydroxycarboxylic acids from cycloalkanes
New Biotech. 60 , 200 - 206