Construction And Study Of Sustained Hydrogen Production From Chlorella Pyrenoidosa

Biohydrogen production has attracted extensive attention from researchers due to its cleanliness and low cost.Some biological cells have hydrogenases capable of reduce proton hydrogen to produce hydrogen.However,hydrogenase is very easy to inactivate,and with the apoptosis of the cell,they cannot continue to provide necessary matter for hydrogen generating,such as photosynthetic electrons,cell can no longer continue to produce hydrogen.so that the hydrogenase inside the ca n not be used.Therefore,based on the cell surface engineering theory,we propose a method for sustained hydrogen production that is independent from the activity of green algae cells.This method of constructing a material transmission bridge inside and outside the cell provide new ideas and methods for the in-depth and extensive use of biological cells and functional development in the future.The specific research contents of this thesis are as follows:Firstly,we build a electron transfer bridge inside and outside the cell.Taking Chlorella protothecoides as the basic organism,modified ferric ions were modified on cellular surface through electrostatic interaction.Based on its oxidation action,pyrrole could be in situ oxidized on the surface of the organism to form polypyrrole.Meanwhile,with the added laccase,we construct polypyrrole-laccase hybrid layer that can transfer external electrons to the inside of the organism.Secondly,we construct an external electron supply system to realize the continuous supply of external electrons to the internal.By adding water-soluble eosin as a photosensitizer to the external medium,it can be changed from the ground state to the excited state under light conditions,and it is easy to transfer electrons to t he conductive medium and change to the oxidized state.As an electron donor,triethanolamine can transfer electrons to the oxidized state photosensitizer,that can make it return to the ground state,complete the electron transfer cycle,to ensure the continuous supply of external electrons.Finally,we create an anaerobic environment.Chlorella protothecoides contains biological hydrogenase,that is easily inactivated under aerobic conditions.Under the effect of continuous internal electron transportation,by adding oxygendepleting substance catechol which can be aerobically catalyzed by laccase,an anaerobic environment was constructed to continuously activate hydrogenase.Thereby,a complete artificial hydrogen production system was constructed to realize continuous hydrogen production independent of the activity of green algae cells.This system maximizes the utilization of the active substance biological enzymes in cells,and the sustainable hydrogen production peroid was about two months,and the average hydrogen production rate in the previous month reached as high as 0.27 ?mol H₂?mg chlorophy II?^-1h^-1.