Study on adaptive evolution of Thermococcus onnurineus NA1 using various substances to develop a superior H2 producer

Abstract

Thermococcus onnurineus NA1 is a hyperthermophilic archaeon, growing optimally at 80 degrees and exhibits a fermentative metabolism with H2 production using diverse substances such as carbon monoxide (CO) and formate as well as sugars. Numerous efforts, including genetic manipulation and adaptive evolution studies, have been conducted to enhance H2 production using various substrates, based on the potential for H2 production of T. onnurineus NA1, which harbors seven [NiFe]-hydrogenases capable of producing H2. Adaptive evolution is a common strategy employed to gain insights on the basic mechanisms of molecular evolution and adaptive changes that accumulate in populations of microorganisms during long term selection under specific growth condition. It is also considered one of the engineering approaches to produce new and fit phenotypes by long-term selection under a defined condition. Recently, we have successfully obtained a superior H2 producer not only in the medium containing each formate, CO and sugar but also when utilizing organic waste material through the adaptive evolution approach. In addition, we performed phenotype confirmation and conducted multi-omics studies on adapted strains obtained under various culture conditions to understand mechanisms associated with enhanced H2 production. Further details on strain development will be introduced in this presentation.