Hydrogen Production By Bacterium Ethanoligenens Harbinense R3 Using Different Substrate

Fossil fuels is the main energy being used at present,but as a result of the continued socio-economic development and human's increasing demand of energy,we are facing enormous energy challenges for the reduction of limited fossil fuels in the 21 st century.Hydrogen as a clean,renewable energy,has been gradually accepted by people,and its combustion does not produce harmful gases,so that it will not cause the greenhouse effect and other air pollution.Hydrogen is one of the most potential energy.Hydrogen has become to a hot issue as its efficiency,clean,safety,and sustainable and may replace fossil fuels step by step.Biological fermentative hydrogen production is different from that the traditional chemical method for it hasn't high cost of energy consumption.The best means of enhancing hydrogen production can be realized by genetically modified bacteria,using different culture medium,at different pH or temperature as well as the substrate concentration and fermentitive time.Bacterium Ethanoligenens harbinense R3 belongs to Gram-positive.It has no spores and is a kind of strictly anaerobic bacteria.The colony's colour is white or milky white,after 20 30 days,it can grow up to a diameter of 1.0～2.5 mm,with the colony edge of neat,round, smooth and opaque.Self-curing ability is markedness when it was cultured using liquid medium.In this paper,biological hydrogen production by bacterium Ethanoligenens Harbinese R3 was discussed using different subftrate.Using batch culture experiment,when the temperature is 30℃,hydrogen production metabolic enzymes is active,and acquired the highest hydrogen yield of 1862 ml/L.The average hydrogen production rate and hydrogen production rate is 1.11 mol H₂/mol glucose 6.91 mmol H₂/ g CDW.h,respectively.Galactose is much more suitable for hydrogen production as a substrate than glucose,fructose and mannose.Effect of degree of starch hydrolysis was discussed by using different concentration of hydrochloric acid and different heating time.The maximum hydrogen yield of 235ml was acquired under the condition of highest reducing sugar content.The end pH of fermentative liquid product is about3.5-4.5.In addition,when the temperature was 35℃,the hydrogen production is better than that of 28℃.Hydrogen production using wheat straw pretreated by different methods is discussed as well as the effect of the liquid end product concentration.Alkali pretreatment method showed to be more suitable for hydrogen production compared with acid pretreatrnent method,it may mostly because of the lignin has been dissolved.In addition,the accumulated hydrogen production increased by 9.2%when adding FeSO₄·7H₂O concentration of 60mg/L into the substrate instead of 10mg/L.