Touloupakis Eleftherios, Poloniataki Eleni G, Ghanotakis Demetrios F, Carlozzi Pietro
Research Institute on Terrestrial Ecosystems, National Research Council, Via Madonna del Piano 10, 50019, Sesto Fiorentino, FI, Italy.
Department of Chemistry, University of Crete, Voutes Campus, 70013, Heraklion, Greece.
Appl Biochem Biotechnol. 2021 Jan;193(1):307-318. doi: 10.1007/s12010-020-03428-1. Epub 2020 Sep 21.
The polyhydroxyalkanoates (PHA) are family of biopolyesters synthesized by numerous bacteria which are attracting a great attention due to their thermoplastic properties. Polyhydroxybutyrate (PHB) is the most common type of PHA which presents thermoplastic and biodegradable properties. It is synthesized under stressful conditions by heterotrophic bacteria and many photosynthetic microorganisms such as purple non-sulfur bacteria and cyanobacteria. Biological hydrogen (H) production is being evaluated for use as a fuel since it is a promising substitute for carbonaceous fuels owing to its high conversion efficiency and high specific content. In the present work, the purple non-sulfur photosynthetic bacterium Rhodopseudomonas sp. for the simultaneous H photo-evolution and poly-β-hydroxybutyrate (PHB) production has been investigated. Three different types of carbon sources were tested in the presence of glutamate as a nitrogen source in a batch cultivation system, under continuous irradiance. The results indicated the fact that the type of carbon source in the culture broth affects in various ways the metabolic activity of the bacterial biomass, as evidenced by the production of PHB and/or H and biomass. The best carbon source for PHB accumulation and H production by Rhodopseudomonas sp. turned out to be the acetate, having the highest H production (2286 mL/L) and PHB accumulation (68.99 mg/L, 18.28% of cell dry weight).
聚羟基脂肪酸酯(PHA)是一类由多种细菌合成的生物聚酯,因其热塑性特性而备受关注。聚羟基丁酸酯(PHB)是PHA中最常见的类型,具有热塑性和可生物降解性。它是在应激条件下由异养细菌以及许多光合微生物(如紫色非硫细菌和蓝细菌)合成的。生物制氢作为一种燃料正在被评估,因为它具有高转化效率和高比含量,有望成为含碳燃料的替代品。在本研究中,对紫色非硫光合细菌红假单胞菌同时进行光驱动产氢和聚-β-羟基丁酸酯(PHB)生产进行了研究。在分批培养系统中,以谷氨酸作为氮源,在连续光照下测试了三种不同类型的碳源。结果表明,培养液中碳源的类型以多种方式影响细菌生物质的代谢活性,这通过PHB和/或氢气的产生以及生物质的情况得到证明。红假单胞菌积累PHB和产氢的最佳碳源是乙酸盐,其产氢量最高(2286 mL/L),PHB积累量为(68.99 mg/L,占细胞干重的18.28%)。