Biological Synthesis and Materials Properties of Bacterial Polyesters

拟议的研究计划将阐明分子和 参与细胞内合成的超分子过程 通过细菌和它们的细胞内和细胞外 通过酶进行细胞外解聚。 的具体目标 程序包括：（1）了解细胞运输 涉及利用以下物质的过程和生物化学反应： (a)良好生长的生产良好聚合物的基质，（B）良好生长的 非生产基质，和（c）非生长基质，特别是 在（a）+（B）和（a）+（c）的混合物的混合物中， 来自非生产性底物（B）和（c）的共聚物是 生产;（2）对所涉及的酶促过程的理解 在颗粒内的聚合物形成中，特别是数量， 聚合酶的活性和位置，以及 分离的颗粒参与胞外聚合 （3）理解相互作用; 解聚酶和单个聚合物分子，特别是 在固体表面上。 该计划的其他目标包括 （i）制备全新的非天然聚酯， 评估其材料特性（包括生物降解性）， （二）促进基本的 用聚合物了解彗星的生物化学 生产作为一个模型系统;和（iii）隔离和表征 分泌的细胞内聚合酶和解聚酶 细菌和真菌可以利用这些聚酯作为生长 基质在自然环境中的生物降解。 %%% 聚酯已被证明是极其通用的热塑性塑料， 广泛用于许多工业产品。 它们可以被制造成 薄膜、纤维和模制产品。 聚酯也可用于 包装以及纯形式，或与羊毛混合时， 棉花等，服装材料。 这些产品生产 从石油中提取的化学物质提供了许多有用的和必要的 用于工业和医疗用途的物品。 然而，因为他们是 从石油馏分中合成有机化学品，它们是 在任何已知的现有工艺和废物处理中不可生物降解 这些产品的质量问题在世界范围内日益严重。 可以制造具有相同化学组成和性能的聚酯， 大量的细菌。 因为它们是由 与化学合成相反，它们产生有规立构的 可完全生物降解的聚合物。 基本上，这些 细菌利用生物合成聚酯作为食物。 理论上，这些 聚酯可以像任何有机废物一样处理以进行处置。 我们 将进行一项酶机制的研究， 这些新生物材料的降解。 此外，我们还展示了 这些细菌或“天然”聚酯具有许多新的 化学品无法复制的潜在特性 合成. 例如我们发现了一种细菌 合成作为弹性体的聚酯，即其表现为 橡胶. 在许多产品的生产中使用这种产品-- 例如可生物降解的外科手套或尿布， 可生物降解的塑料衬里将是解决这一问题的一大进步。 塑料垃圾处理问题。

The proposed research program would elucidate the molecular and supermolecular processes involved in the intracellular synthesis of reserve polyesters by bacteria and their intracellular and exocellular depolymerization by enzymes. Specific goals of the program include: (1) an understanding of the cellular transport processes and biochemical reactions involved in the utilization of: (a) good-growth good-polymer producing substrates, (b) good-growth non-producing substrates, and (c) non-growth substrates, especially in the cometabolism of mixtures of (a)+(b) and of (a)+(c) by which the coploymers from the non-productive substrates, (b) and (c), are produced; (2) an understanding of the enzymatic processes involved in polymer formation within the granule, especially the number, activity and location of the polymerase enzymes and the ability of isolated granules to participate in extracellular polymerization reactions; (3) an understanding of the interaction between depolymerase enzymes and individual polymer molecules, especially on solid surfaces. Additional goals of the program include the following: (i) to prepare entirely new, non-natural polyesters and evaluate their materials properties (including biodegradability) as plastics or elastomers; (ii) to contribute to the basic understanding of the biochemistry of cometabolism by using polymer production as a model system; and (iii) to isolate and characterize the intracellular polymerase and depolymerase enzymes excreted by bacteria and fungi that can utilize these polyesters as growth substrates in their biodegradation in natural environments. %%% Polyesters have proven to be extremely versatile thermoplastics in wide use in many industrial products. They can be fabricated into films, fibers and molded products. Polyester can also be used for packaging as well as in pure form, or when blended with wool, cotton, etc., for clothing material. These products produced chemically from petroleum provide many useful and indeed necessary items for industrial and medical uses. However, because they are synthetic organic chemicals from petroleum distallates, they are not biodegradable in any known current process and waste disposal of these products is an increasing problem world wide. Polyesters of identical chemical makeup and properties can be made by a large number of bacteria. Because they are made by enzymes in cells as opposed to chemical synthesis, they produce stereoregular polymers which are fully biodegradable. Essentially, these bacteria use biosynthetic polyesters as food. Theoretically these polyesters can be treated for disposal like any organic waste. We will be undertaking a study of the enzymatic mechanisms of degradation of these new biomaterials. In addition we have shown that these bacterial or "natural" polyesters have many new and potential properties that cannot be duplicated by chemical synthesis. For instance we have discovered a bacterium that can synthesize a polyester that is an elastomer, i.e. it behaves like rubber. The use of such a product in the production of many items-- surgical gloves for example that are biodegradable or diapers with biodegradable plastics liners would be a big advance in solving the plastic waste disposal problem.