Breeding Of Anaerobic Fermentative Hydrogen Production Strains And Primary Study On Their Fermentation Conditions

As an ideal, clean and sustainable energy source, hydrogen has a bright future inthe 21st century. It has many other uses as well as energy, such as a reactant inhydrogenation process, an O₂ scavenger, a fuel in rocket engines and a coolant inelectrical generators to take advantage of its unique physical properties. Biologicalproduction of hydrogen, using organisms, is an exciting new area of technologydevelopment that offers the potential production of usable hydrogen from a variety ofrenewable resources.Two strains with the high ability to produce hydrogen, HB-5, bacteria, andHY-35, yeast, were isolated from the activated sludge. Then the two strains wereidentified as Enterobacter aerogenes and Candida maltosa respectively after beinginvestigated the morphologic and taxonomic properties. Further study showed thatunder the optimum fermentation conditions, the hydrogen producing ability of E.aerogenes HB-5 improved by 19.9% (Qmax) and 15.8% (Y), respectively.He-Ne laser was employed to irradiate the cells of the strain E. aerogenes HB-5to obtain the mutant with the higher hydrogen producing ability. A steady-goingpositive mutant strain, E. aerogenes HB-5M, with Qmax=242.0 ml H₂/(L media ·h), Y=1483 ml H₂/(L media) which were 32.2% and 23.3% higher than those of the wildstrain, was acquired. Moreover, the dynamics study on the cell growth, productionand substrate degradation indicated that the simulated values agreed well with theexperimental data under the selected model.Furthermore, hydrogen production by the mixed culture of E. aerogenes HB-5Mand C. maltosa HY-35 and their optimization of the mixed culture fermentativecondition were also investigated. The results showed that the mixed culture has ahigher ability.