Study On Fermentation Hydrogen Production By Thermococcus Eurythermalis A501 With Dunaliella Algal Biomass As Substrate

In the face of the intensified crisis of fossil energy and environmental pollution,the use of renewable biomass energy to replace traditional energy has become a new research direction.Microalgae biomass energy,as the source of the third-generation biofuel,has attracted wide attention in the field of biodiesel.However,the process is still not economically feasible,and the high cost is the main reason that restricts the industrialization of microalgae biomass energy.Dark fermentation which combines hydrogen-producing bacteria with microalgal biomass can increase the energy conversion efficiency of microalgae biomass while reducing the total cost.Besides,the development and utilization of deep-sea resources have attracted more attention in recent years,and many previous studies have reported that high-temperature conditions are more conducive to hydrogen production by dark fermentation.Based on this,combined with the comprehensive utilization of microalgae biological resources,the deep-sea archaeon Thermococcus eurythermalis A501 was used to conduct research on dark fermentation using Dunaliella biomass as the substrate.Comparison results of hydrogen production showed that when lipid-extracted Dunaliella residue was used as the fermentation substrate,the hydrogen yields of T.eurythermalis A501 could be greatly promoted,which are more than 4 times higher than with algal cells as substrates.Under the optimal conditions of 2.5 g/L algal residue concentration and a 2:1 initial volume ratio of gas to liquid,the kinetic fitting results showed that T.eurythermalis A501 could efficiently complete the hydrogen production reaction in 19 h using Dunaliella primolecta and Dunaliella tertiolecta as substrates.When the algal residue was not pretreated,the accumulation of hydrogen in this model was still high,and the accumulative hydrogen production of D.primolecta and D.tertiolecta as substrates were 192.35 m L/g VS and 183.02 m L/g VS,respectively.The results verified the superiority of the hydrogen production mode that combine Thermococcus eurythermalis A501 with lipid-extracted Dunaliella biomass,thus providing scientific basis for further reducing the development cost of microalgae bioenergy while exploring the hydrogen production potential of deep-sea thermophiles resources.