Screening And Application Of Highly Efficient Hydrogen-Producing Photosynthetic Bacteria

Hydrogen energy,as a new clean energy substitute for fossil energy,is developing rapidly.However,most traditional hydrogen production methods have the disadvantages of resource waste,associated pollutants and high cost.Biological hydrogen production has the advantages of clean and environmental protection,wide range of raw materials,low cost,no pollution and low energy consumption.Among them,the abundant biomass resources which are in urgent need of resource utilization will become the main raw materials.Peanut shell has high research value and practical application value because of its high yield,porosity and high content of cellulose,hemicellulose and other substances.The purpose of this study is to obtain a strain of highly efficient hydrogen-producing photosynthetic bacteria,and at the same time to improve the utilization rate of peanut shell resources,and then combined with the advantages of hydrogen production by fermentation of highly efficient hydrogen-producing photosynthetic bacteria,to improve the theoretical and technical basis for the application research of hydrogen production by photosynthetic bacteria.The research conclusions are as follows:(1)The hydrolysis process of peanut shell was investigated by acid,alkali and enzyme hydrolysis methods,and the content of reducing sugar and average hydrolysis rate were determined.The results showed that the concentration of reducing sugar was 6.3g/L at 135? and 70min.When the acidolysis temperature was 125? and the time was 10min,the reducing sugar concentration was 27.13 g/L.The optimal reducing sugar concentration under enzymatic hydrolysis was 19.2 g/L.The concentration of reducing sugar was higher than 20 g/L and the average hydrolysis rate was more than 30%.(2)29 strains of photosynthetic bacteria were isolated and purified from lake water,poultry feces and soil.One strain was isolated from sheep feces and identified as Rhodobacter sphaeroides by 16S rRNA sequence analysis,and was named Rhodobacter sphaeroides.The optimal hydrogen production conditions of Rhodobacter sphaeroides.LZY01 were determined as follows:carbon source was glucose,glucose concentration was 5.0 g/L,nitrogen source was L-glutamic acid,initial pH of hydrogen production solution was 7.2,salinity was 0.5 g/L,phosphate concentration was 20.0 mL/L,hydrogen production could reach 3154.82 mL H2/L,and the maximum hydrogen production rate was 69.18mL/(L·h).(3)In the treatment of peanut shell hydrolysate by Rhodobacter sphaeroides.LZY01,the key parameters of hydrogen production process were studied by response surface methodology(RSM).Under the conditions of carbon source concentration 5.63 g/L,pH 9 and salinity 0 g/L,the maximum hydrogen production is 2337.93 mL H2/L.Relevant verification experiments were carried out in the later stage,and the results showed that the hydrogen production of Rhodobacter sphaeroides.LZY01 was considerable under these conditions,and the optimized conditions in this experiment were reasonable and feasible.In this study,Rhodobacter sphaeroides.LZY01 was used to test hydrogen production from the hydrolysate of peanut shell treated by enzymatic hydrolysis process.It provides new bacteria resources for hydrogen production by microorganisms,and optimizes the hydrolysis process parameters of peanut shell,which provides theoretical guidance for hydrogen production from the hydrolysate of peanut shell.