Study On Characteristics Of The Magnetic Field Strengthening Biohydrogen By Two Kinds Of Bacillus

Anaerobic fermentation biohydrogen production has been widely utilized because of its availability on raw materials and strong applicability,however it remains some disadvantages such as complicated pretreatment and high cost.This research group has early discovered that with application of static magnetic field,both microbial activity and hydrogen production by pure bacteria and sludge could be improved,while the whole process is still expected further analysis on its mechanism.Therefore,this paper takes pure Bacillus sp.BH01,pure Bacillus sp.BH03 and mixed bacteria(Bacilus sp.BH01:Bacilus sp.BH03 = 1:1)as research target,to determine suitable hydrogen production condition,and effects of magnetic field on bacterial hydrogen production with different carbon source has been researched.Moreover,the machanism of this method has been further resolved by analysis on bacterial growth,process dehydrogenase activity and electron transport chain activity,and conclusion listed as follows:(1)Suitable hydrogen production conditions of bacteria BH01,bacteria BH03 and mixed bacteria are 8 of initial pH value,8%of the amout of bacteria,10 g/L of initial glucose concentration.(2)Enhancement on hydrogen production by magnetic field has been obtained both on bacteria BH01,BH03 and mixed bacteria.Hydrogen production rate is obtained at the maximum with application of 54 mT magnetic field,when the carbon source of which are xylose,glucose and maltose.Comparing to non-magnetic condition,the effect of enhancement which bacteria BH01 and BH03 produce hydrogen by different carbon source is xylose>glucose>maltose.Higher hydrogen production rate of mixed bacteria has been found by using glucose and maltose as carbon source,which is 0.83 molH2/molglucose and 0.83 molH2/molmaltose,and it increases by 50.9%and 62.8%compared to that of non-magnetic condition,repectively.(3)Different ratios of acetic acid and ethanol has been obtained in the liquid phase fermentation product in hydrogen production of three systems using different carbon source under 54 mT of magnetic field.Ratio of acetic acid and ethanol of bacteria BH01 is 0,67 ± 0.1,while that of BH03 is 0.33 ±0.3.Moreover,competitive relationship happens between bacteria BH01 and bacteria BH03 when mixed bacteria is producing hydrogen.When mixed bacteria uses xylose as substrate to produce hygrogen,bacteria BH03 takes advantage.However,when mixed bacteria uses glucose and maltose as substrate to produce hygrogen,bacteria BH01 takes advantage.(4)Application of magnetic field would not change fermentation type and growth of these bacterium.Instead,dehydrogenase activity and electron transport chain activity of them are increased.Dehydrogenase activity under 54 mT of magnetic field strength improves 40.5%,60.9%and 99.2%compared to non-magnetic field condition,and electron transport chain activity under 54 mT of magnetic field strength improves 30.8%,22.5%and49%compared to non-magnetic field condition,respectively.