[2S04m] 18. Biorefinery and Bioproduction - Part 1

11:15 AM - 11:30 AM JST(2:15 AM - 2:30 AM UTC)

[2BRBP-04] A metabolically versatile bacterium for biomanufacturing using chemically synthesized atypical sugars

○Natsu Iwama¹, Hiroaki Nishijima¹, Hiro Tabata^1,2, Kensuke Igarashi³, Souichiro Kato^1,3,4, Shuji Nakanishi¹ (1. Research Center for Solar Energy Chemistry, Graduate School of Engineering Science, The University of Osaka (Japan), 2. Presidential Endowed Chair for "Platinum Society", The University of Tokyo (Japan), 3. Biomanufacturing Process Research Center, National Institute of Advanced Industrial Science and Technology (Japan), 4. Graduate School of Agricultural and Life Sciences, The University of Tokyo (Japan))

Keywords:

Chemically synthesized sugars,Bioproduction technology,Environmental microbial biotechnology,Metabolic pathways,Microbial Ecology,Transcriptome analysis

Toward the realization of a sustainable society, bioproduction of valuable compounds from biomass-derived sugars has attracted considerable attention. However, biomass-derived sugars are generally obtained from crops such as corn, and their utilization relies on production in suitable agricultural regions followed by transportation to consumption sites. Furthermore, their supply faces challenges, including climate-induced yield fluctuations and geopolitical instability. To address these issues, our research group aims to establish a bioproduction technology utilizing chemically synthesized sugars, which can be supplied more rapidly and stably than biomass-derived sugars¹⁾. Chemically synthesized sugars are racemic mixtures containing sugars rare or absent in nature (atypical sugars). Conventional industrial microbial hosts utilize only the naturally abundant sugars (typical sugars) present in such mixtures. In this study, we isolated an environmental microbial strain capable of efficiently utilizing chemically synthesized sugars. Analysis of the culture supernatant after growth on these sugars revealed that both D- and L-enantiomers of multiple sugars were consumed. While the metabolic pathways for typical sugars have been well characterized, atypical sugars include compounds for which assimilability has not previously been reported, and their metabolic pathways remain largely unknown. Here, we conducted cultivation experiments using various D- and L-sugars as the sole carbon source, together with gene expression analyses, to elucidate previously uncharacterized metabolic pathways. We observed high expression levels of substrate-specific transporters and metabolic enzymes. These findings suggest that specific enzymes mediate the metabolism of each sugar, rather than promiscuous ones.
1) Tabata, et al., ChemBioChem 2024, 25, e202300760