BioChem - DOS

Comparative kinetic modeling of growth and molecular hydrogen overproduction by engineered strains of Thermotoga maritima

International journal of hydrogen energy

Singh, Raghuveer; Tevatia, Rahul; White, Derrick; Demirel, Yaş ar; Blum, Paul

<P><B>Abstract</B></P> <P> <I>Thermotoga maritima</I> is an anaerobic hyperthermophilic bacterium known for its high amounts of hydrogen (H<SUB>2</SUB>) production. In the current study, the kinetic modeling was applied on the engineered strains of <I>T. maritima</I> that surpassed the natural H<SUB>2</SUB> production limit. The study generated a kinetic model explaining H<SUB>2</SUB> overproduction and predicted a continuous fermentation system. A Leudking-Piret equation-based model predicted that H<SUB>2</SUB> production by Tma200 (0.217 mol-H<SUB>2</SUB> g<SUP>&minus;1</SUP>-biomass) and Tma100 (0.147 mol-H<SUB>2</SUB> g<SUP>&minus;1</SUP>-biomass) were higher than wild type (0.096 mol-H<SUB>2</SUB> g<SUP>&minus;1</SUP> -biomass) with reduced rates of maltose utilization. Sensitivity analysis confirmed satisfactory fitting of the experimental data. The slow growth rates of Tma200 (0.550 h<SUP>&minus;1</SUP>) and Tma100 (0.495 h<SUP>&minus;1</SUP>) are compared with the wild type (0.663 h<SUP>&minus;1</SUP>). A higher maintenance energy along with growth and non-growth H<SUB>2</SUB> coefficients corroborate the higher H<SUB>2</SUB> productivity of the engineered strains. The modeled data established a continuous fermentation system for the sustainable H<SUB>2</SUB> production.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Hydrogen (H<SUB>2</SUB>) synthesis was studied in engineered strains (ES) of <I>Thermotoga maritima.</I> </LI> <LI> Kinetic modeling determined the correlation between metabolites and growth. </LI> <LI> The p-type metabolism in ES produced more H<SUB>2</SUB> than the q-type metabolism in wild type. </LI> <LI> Carbon rerouting increased maintenance energy to yield H<SUB>2</SUB> beyond 4 mol mol<SUP>&minus;1</SUP>hexose. </LI> <LI> Continuous hydrogen production was simulated for sustainable hydrogen production. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

2019

Elsevier

publisher-specific-oa

0360-3199

1879-3487

44

14

pp.7125-7136

10.1016/j.ijhydene.2019.01.124

http://click.ndsl.kr/servlet/OpenAPIDetailView?keyValue=05787966&target=NART&cn=NART95413551

http://manuscript.elsevier.com/S0360319919302563/pdf/S0360319919302563.pdf

Bio hydrogen beyond Thauer limit; Biofuel; Dark fermentation; Kinetic modeling; Continuous stirred tank reactor; Natural gas phase out