Scheel Ryan A, Fusi Alexander D, Min Byeong C, Thomas Christopher M, Ramarao Bandaru V, Nomura Christopher T
Department of Chemistry, State University of New York College of Environmental Science and Forestry, Syracuse, NY, United States.
Department of Paper and Bioprocess Engineering, State University of New York College of Environmental Science and Forestry, Syracuse, NY, United States.
Front Bioeng Biotechnol. 2019 Dec 18;7:409. doi: 10.3389/fbioe.2019.00409. eCollection 2019.
Reject fines, a waste stream of short lignocellulosic fibers produced from paper linerboard recycling, are a cellulose-rich paper mill byproduct that can be hydrolyzed enzymatically into fermentable sugars. In this study, the use of hydrolyzed reject fines as a carbon source for bacterial biosynthesis of poly(-3-hydroxyalkanoate) (PHA) and poly(γ-glutamic acid) (PGA) was investigated. Recombinant harboring PHA biosynthesis genes were cultivated with purified sugars or crude hydrolysate to produce both poly(-3-hydroxybutyrate) (PHB) homopolymer and medium chain length-containing copolymer (PHB--MCL). Wild-type WX-02 were cultivated with crude hydrolysate to produce PGA. Both PHB and short chain-length--medium chain-length (SCL--MCL) PHA yields from crude hydrolysate were a 2-fold improvement over purified sugars, and the MCL monomer fraction was decreased slightly in copolymers produced from crude hydrolysate. PGA yield from crude hydrolysate was similarly increased 2-fold. The results suggest that sugars from hydrolyzed reject fines are a viable carbon source for PHA and PGA biosynthesis. The use of crude hydrolysate is not only possible but beneficial for biopolymer production, eliminating the need for costly separation and purification techniques. This study demonstrates the potential to divert a lignocellulosic waste stream into valuable biomaterials, mitigating the environmental impacts of solid waste disposal.
来自纸挂面纸板回收产生的短木质纤维素纤维废料是一种富含纤维素的造纸厂副产品，可通过酶水解转化为可发酵糖。在本研究中，研究了使用水解后的废料作为细菌生物合成聚（-3-羟基链烷酸酯）（PHA）和聚（γ-谷氨酸）（PGA）的碳源。携带PHA生物合成基因的重组体用纯化糖或粗水解产物培养，以生产聚（-3-羟基丁酸酯）（PHB）均聚物和含中链长度的共聚物（PHB-MCL）。野生型WX-02用粗水解产物培养以生产PGA。与纯化糖相比，粗水解产物中PHB和短链长度-中链长度（SCL-MCL）PHA的产量提高了2倍，并且由粗水解产物生产的共聚物中MCL单体分数略有下降。粗水解产物中PGA产量同样提高了2倍。结果表明，水解废料中的糖是PHA和PGA生物合成的可行碳源。使用粗水解产物不仅可行，而且对生物聚合物生产有益，无需昂贵的分离和纯化技术。本研究证明了将木质纤维素废物流转化为有价值生物材料的潜力，减轻了固体废物处置对环境的影响。
