Candida tropicalis (PV544892) を用いたバナナ茎繊維廃棄物のキシリトールへの微生物変換

Banana pseudostem scutcher waste, an abundant yet underutilized lignocellulosic residue from banana fibre extraction, was explored as a renewable substrate for microbial xylitol production. Seventeen yeast isolates obtained from banana residues were screened, and the four isolates, Saccharomycopsis fibuligera (S1), Pichia kudriavzevii (S6), Candida tropicalis (S7) and Cyberlindnera saturnus (S15) were identified through ITS rDNA sequencing. Among these, C. tropicalis S7 exhibited strong tolerance to inhibitory compounds and efficient xylose assimilation. During fermentation, the isolate showed robust growth, reaching peak biomass at 72 h, outperforming all other strains. It also produced the highest xylitol yield (0.81 g/g), followed by S. fibuligera and P. kudriavzevii, which exceeded the control strain. Mass balance confirmed the potential production of xylitol through the microbial conversion of xylose derived from hemicellulose. Structural characterization by XRD and FTIR confirmed that the biosynthesized xylitol possessed comparable crystalline and functional profiles to commercial xylitol. This study demonstrates the technical feasibility of converting banana scutcher into xylitol and identifies C. tropicalis S7 as an effective biocatalyst. The findings provide a foundation for further process optimization studies under controlled fermentation conditions.