Lignin bioconversion into polyhydroxybutyrate (PHB) has emerged as a promising valorization, however, it is suffering from inadequate conversion efficiency. Herein, an efficient strategy for addressing this challenge by employing an alkali-halophilic strain Halomonas alkalicola M2 is developed. Up to 58.5% of lignin is degraded when incubates in the non-sterilized lignin (NSL) medium under a glucose concentration of 1.055 g/L, peptone concentration of 0.596 g/L, and incubation time of 6.89 d, demonstrating enhanced proficiency compared to thermally sterilized lignin (TSL) method due to the improved cell growth, lignin-degrading enzyme activities, and secreted protein contents. Consequently, PHB production demonstrates a 50% increase using NSL method compared to TSL method. A separate route of enzymatic hydrolysis and fermentation (SHF) is proposed to further improve the PHB production, resulting in a record yield of PHB which is 1.89 g/L. This work creatively develops a non-sterilization strategy to improve PHB production from lignin, showing great potential for promoting biological lignin valorization.

木质素生物转化为聚羟基丁酸酯 (PHB) 已成为一种很有前途的增值方式，但它的转化效率不足。在此，通过使用嗜碱嗜盐菌株Halomonas alkalicola来应对这一挑战的有效策略M2开发。在葡萄糖浓度为 1.055 g/L、蛋白胨浓度为 0.596 g/L、孵育时间为 6.89 天的情况下，在未灭菌木质素 (NSL) 培养基中孵育时，高达 58.5% 的木质素被降解，与热灭菌木质素 (TSL) 方法由于改善了细胞生长、木质素降解酶活性和分泌的蛋白质含量。因此，与 TSL 方法相比，使用 NSL 方法的 PHB 产量增加了 50%。提出了一种单独的酶水解和发酵 (SHF) 路线，以进一步提高 PHB 的产量，从而使 PHB 的产量达到创纪录的 1.89 g/L。这项工作创造性地开发了一种非灭菌策略来提高木质素的 PHB 产量，显示出促进生物木质素增值的巨大潜力。