Isolation of bacteria that catabolize abiotically synthesized tetroses via the formose reaction

Abstract

Sugars synthesized through abiotic processes, specifically the formose reaction, are promising candidates for next-generation feedstocks for biomanufacturing due to their significantly higher productivity compared to cultivated crops. One of the significant challenges associated with the utilization of abiotically synthesized sugars via the formose reaction is the presence of unusual sugars, which are not metabolized by typical microorganisms. This study aimed to identify microorganisms capable of catabolizing tetroses, which are among the unusual sugars present in the abiotically synthesized sugars. Four model bacteria commonly used in biomanufacturing, including Escherichia coli, were unable to catabolize tetroses and their growth was completely inhibited by 2 to 4 g/L of D-erythrose or 0.5 to 1 g/L of L-erythrulose. We successfully isolated eight phylogenetically diverse bacterial strains from river sediments, capable of utilizing D-erythrose and L-erythrulose as the sole carbon sources. These isolates exhibited higher tolerances to tetroses compared to the model bacteria. The isolates exhibited the ability to grow in high concentrations of the abiotically synthesized sugars, which inhibit the growth of typical microorganisms, and to consume tetroses contained therein. Further investigation into the molecular mechanisms of tetrose metabolisms in the isolates will facilitate the development of biomanufacturing processes utilizing the abiotically synthesized sugars.