Sucrose-Based Screening of a Novel Strain, Limimaricola sp. YI8, and Its Application to Polyhydroxybutyrate Production from Molasses

Poly(3-hydroxybutyrate) is a biodegradable plastic produced by various microbes. Considering the emerging environmental problems caused by plastics, P(3HB) has gained attention as a substitute for conventional plastics. In this study, we isolated a novel P(3HB)-producing microbe, <i>Limimaricola</i> sp. YI8, which utilized sucrose as a cost-effective carbon source for P(3HB) production. Under optimized conditions, <i>Limimaricola</i> sp. YI8 produced 6.2 g/L P(3HB) using sucrose as the sole carbon source. P(3HB) extracted from YI8 exhibited a pinkish color derived from a dye produced naturally by YI8. Films fabricated from extracted P(3HB) polymer were subjected to analyses, including gel permeation chromatography, universal test machine, and differential scanning calorimetry, to determine their physical properties. The obtained values were almost identical to those of P(3HB) films extracted from <i>Escherichia coli</i> and <i>Cupriavidus necator</i> H16. Overall, this study presents the potential of <i>Limimaricola</i> spp. YI8 as a P(3HB)-producing strain and the P(3HB) films extracted from this strain.