Robot-assisted phenotyping of a Corynebacterium strain library towards valorization of next-generation feedstocks

The identification of microorganisms capable of efficiently using the different carbon sources (sugars, sugar acids, and sugar alcohols) and tolerating inhibitory by-products in hydrolysates is a challenge for the development of efficient bioproduction from lignocellulosic biomass (LCB). In this study, a robot-assisted screening approach was developed to characterize a collection of 32 Actinomycetes type strains, mainly belonging to the genus Corynebacterium. Using robot-assisted replica plating, the use of 12 different carbon-sources as well as the level of tolerance against prominent inhibitors derived from LCB was assessed. Based on a combined analysis of substrate utilization profiles and inhibitor tolerance five strains were chosen for further characterization in a miniaturised cultivation system using ultrafiltrated spent sulfite liquor (SSL) as the sole substrate. Noteworthy, in these experiments Corynebacterium sp. ATCC 14747 showed fast growth and biomass accumulation even in presence of high SSL concentrations.