Accumulation of non-degradable plastic waste in the environment might be prevented by the use of biodegradable polyhydroxyalkanoate (PHA). In this study, the thermophile Schlegelella thermodepolymerans produced up to 80 wt% PHA based on dry cell mass. The largest PHA granules were found in the cells within 48 h using 20 g/L xylose, a C/N ratio of 100, an initial pH of 7, at 50 °C. The substrate consumption, pH changes, and cell growth were monitored, revealing the time dependency of PHA production in S. thermodepolymerans. The metabolic pathways from xylose to PHA were identified based on proteomic analysis, revealing involvement of classic phaCAB, de novo fatty acid biosynthesis, and fatty acid β-oxidation. In addition, it was shown that S. thermodepolymerans degraded extracellular PHA with a high efficiency at 50 °C.

使用可生物降解的聚羟基链烷酸酯 (PHA) 可以防止环境中不可降解塑料废物的积累。在这项研究中，嗜热菌Schlegelella thermodepolymerans产生了高达 80 wt% 的 PHA（基于干细胞质量）。使用 20 g/L 木糖、C/N 比为 100、初始 pH 值为 7、在 50 °C 下，48 小时内在细胞中发现了最大的 PHA 颗粒。监测了底物消耗、pH 变化和细胞生长，揭示了S. thermodepolymerans中 PHA 生产的时间依赖性。基于蛋白质组学分析确定了从木糖到 PHA 的代谢途径，揭示了经典的 phaCAB、从头脂肪酸生物合成和脂肪酸 β-氧化的参与。此外，还表明S. thermodepolymerans在 50 °C 下高效降解细胞外 PHA。