Centre for Advanced Computational Solutions, Department of Molecular Biosciences, Lincoln University, Ellesmere Junction Road, Lincoln, 7647, New Zealand,
J Ind Microbiol Biotechnol. 2013 Oct;40(10):1161-80. doi: 10.1007/s10295-013-1308-0. Epub 2013 Jul 14.
Synechocystis sp. PCC 6803 has been considered as a promising biocatalyst for electricity generation in recent microbial fuel cell research. However, the innate maximum current production potential and underlying metabolic pathways supporting the high current output are still unknown. This is mainly due to the fact that the high-current production cell phenotype results from the interaction among hundreds of reactions in the metabolism and it is impossible for reductionist methods to characterize the pathway selection in such a metabolic state. In this study, we employed computational metabolic techniques, flux balance analysis, and flux variability analysis, to exploit the maximum current outputs of Synechocystis sp. PCC 6803, in five electron transfer cases, namely, ferredoxin- and plastoquinol-dependent electron transfers under photoautotrophic cultivation, and NADH-dependent mediated electron transfer under photoautotrophic, heterotrophic, and mixotrophic conditions. In these five modes, the maximum current outputs were computed as 0.198, 0.7918, 0.198, 0.4652, and 0.4424 A gDW⁻¹, respectively. Comparison of the five operational modes suggests that plastoquinol-/c-type cytochrome-targeted electricity generation had an advantage of liberating the highest current output achievable for Synechocystis sp. PCC 6803. On the other hand, the analysis indicates that the currency metabolite, NADH-, dependent electricity generation can rely on a number of reactions from different pathways, and is thus more robust against environmental perturbations.
集胞藻 PCC 6803 最近在微生物燃料电池研究中被视为一种很有前途的生物催化剂，可用于发电。然而，支持高电流输出的固有最大电流产生潜力和潜在代谢途径仍不清楚。这主要是因为高电流产生细胞表型是由代谢中的数百个反应相互作用产生的，而还原论方法不可能在这种代谢状态下对途径选择进行特征描述。在这项研究中，我们采用计算代谢技术、通量平衡分析和通量可变性分析，以探索集胞藻 PCC 6803 在五种电子传递情况下的最大电流输出，即光自养培养下依赖于铁氧还蛋白和质体醌的电子传递，以及光自养、异养和混合营养条件下依赖于 NADH 的介导电子传递。在这五种模式下，最大电流输出分别计算为 0.198、0.7918、0.198、0.4652 和 0.4424 A gDW⁻¹。对这五种操作模式的比较表明，质体醌/c 型细胞色素靶向发电具有释放集胞藻 PCC 6803 可实现的最高电流输出的优势。另一方面，分析表明，依赖于货币代谢物 NADH 的发电可以依赖于来自不同途径的许多反应，因此对环境扰动更具鲁棒性。
