Salmela Milla, Lehtinen Tapio, Efimova Elena, Santala Suvi, Mangayil Rahul
Laboratory of Chemistry and Bioengineering, Tampere University of Technology, Korkeakoulunkatu 8, Tampere, Finland.
Biotechnol Biofuels. 2018 Jul 3;11:187. doi: 10.1186/s13068-018-1186-9. eCollection 2018.
The versatility of microbial metabolic pathways enables their utilization in vast number of applications. However, the electron and carbon recovery rates, essentially constrained by limitations of cell energetics, are often too low in terms of process feasibility. Cocultivation of divergent microbial species in a single process broadens the metabolic landscape, and thus, the possibilities for more complete carbon and energy utilization.
In this study, we integrated the metabolisms of two bacteria, an obligate anaerobe and an obligate aerobe ADP1. In the process, a glucose-negative mutant of ADP1 first deoxidized the culture allowing to grow and produce hydrogen from glucose. In the next phase, ADP1 produced long chain alkyl esters (wax esters) utilizing the by-products of , namely acetate and butyrate. The coculture produced 24.5 ± 0.8 mmol/l hydrogen (1.7 ± 0.1 mol/mol glucose) and 28 mg/l wax esters (10.8 mg/g glucose).
The cocultivation of strictly anaerobic and aerobic bacteria allowed the production of both hydrogen gas and long-chain alkyl esters in a simple one-pot batch process. The study demonstrates the potential of 'metabolic pairing' using designed microbial consortia for more optimal electron and carbon recovery.
微生物代谢途径的多功能性使其能应用于大量领域。然而，受细胞能量学限制，电子和碳的回收率在工艺可行性方面往往过低。在单一过程中共培养不同的微生物物种可拓宽代谢范围，从而增加更完全地利用碳和能量的可能性。
在本研究中，我们整合了两种细菌的代谢，一种是专性厌氧菌，另一种是专性需氧菌ADP1。在此过程中，ADP1的一个葡萄糖阴性突变体首先对培养物进行脱氧，使能够生长并利用葡萄糖产生氢气。在下一阶段，ADP1利用的副产物，即乙酸盐和丁酸盐，生产长链烷基酯（蜡酯）。共培养物产生了24.5±0.8 mmol/l氢气（1.7±0.1 mol/mol葡萄糖）和28 mg/l蜡酯（10.8 mg/g葡萄糖）。
严格厌氧和好氧细菌的共培养使得在一个简单的一锅式分批过程中既能产生氢气又能产生长链烷基酯。该研究证明了使用设计的微生物群落进行“代谢配对”以实现更优化的电子和碳回收的潜力。
