Department of Biology, University of Padua, via U. Bassi 58/b, 35131 Padova, Italy.
CALAGUA - Unidad Mixta UV-UPV, Departament d'Enginyeria Química, Universitat de València, Avinguda de la Universitat s/n, 46100 Burjassot, Valencia, Spain.
Biotechnol Adv. 2023 Dec;69:108264. doi: 10.1016/j.biotechadv.2023.108264. Epub 2023 Sep 27.
Cupriavidus necator is a bacterium with a high phenotypic diversity and versatile metabolic capabilities. It has been extensively studied as a model hydrogen oxidizer, as well as a producer of polyhydroxyalkanoates (PHA), plastic-like biopolymers with a high potential to substitute petroleum-based materials. Thanks to its adaptability to diverse metabolic lifestyles and to the ability to accumulate large amounts of PHA, C. necator is employed in many biotechnological processes, with particular focus on PHA production from waste carbon sources. The large availability of genomic information has enabled a characterization of C. necator's metabolism, leading to the establishment of metabolic models which are used to devise and optimize culture conditions and genetic engineering approaches. In this work, the characteristics of available C. necator strains and genomes are reviewed, underlining how a thorough comprehension of the genetic variability of C. necator is lacking and it could be instrumental for wider application of this microorganism. The metabolic paradigms of C. necator and how they are connected to PHA production and accumulation are described, also recapitulating the variety of carbon substrates used for PHA accumulation, highlighting the most promising strategies to increase the yield. Finally, the review describes and critically analyzes currently available genome-scale metabolic models and reduced metabolic network applications commonly employed in the optimization of PHA production. Overall, it appears that the capacity of C. necator of performing CO bioconversion to PHA is still underexplored, both in biotechnological applications and in metabolic modeling. However, the accurate characterization of this organism and the efforts in using it for gas fermentation can help tackle this challenging perspective in the future.
铜绿假单胞菌是一种表型多样性高、代谢能力多样的细菌。它作为一种模型氢氧化剂以及聚羟基烷酸酯（PHA）的生产者得到了广泛研究，PHA 是一种具有高潜力替代石油基材料的塑料状生物聚合物。由于其对多种代谢方式的适应性以及积累大量 PHA 的能力，铜绿假单胞菌被应用于许多生物技术过程中，特别是在利用废碳源生产 PHA 方面。大量基因组信息的可用性使铜绿假单胞菌的代谢特性得以描述，从而建立了代谢模型，用于设计和优化培养条件和遗传工程方法。在这项工作中，综述了现有铜绿假单胞菌菌株和基因组的特性，强调了对铜绿假单胞菌遗传变异的深入理解缺乏，这对于更广泛地应用这种微生物是至关重要的。描述了铜绿假单胞菌的代谢范例以及它们与 PHA 生产和积累的关系，同时回顾了用于 PHA 积累的各种碳底物，强调了提高产量的最有前途的策略。最后，综述描述并批判性地分析了目前可用于优化 PHA 生产的基因组规模代谢模型和简化代谢网络应用。总的来说，铜绿假单胞菌将 CO 生物转化为 PHA 的能力在生物技术应用和代谢建模方面似乎仍未得到充分探索。然而，对该生物体的精确描述以及将其用于气体发酵的努力，有望帮助未来解决这一具有挑战性的问题。
