The Influence Of Cellulolytic Strains On Solid Carbon Source In Bio-denitrification

Water resource is one of the most precious natural resources which can be an important role for human survival and the development of society. China has huge population and the water resource of per capita is only 1/4 of the world country, which is the extreme lack of water resources country. At the same time, with the development of economic and social, the problem of water pollution is becoming more and more serious, especially the urban sewage of low carbon source sewage processing problem. Due to the nitrogen is too high in the low carbon source sewage, the traditional wastewater treatment methods do bad in denitrification, based on this the development of biological denitrification and phosphorus removal, provide new methods to solve the problem of low carbon source sewage denitrification. For the lake of carbon source in the biological denitrification technology, its need to add solid carbon source in the system, the cellulose solid carbon source has low cost and easy for get and it is reusable. In order to strengthen the solid carbon source's ability of carbon release. This study isolation 2 strains of cellulose degradation bacteria by corn cobs carbon source for the application on the effect of solid carbon source.This study collect humus soil as samples from below fallen leaves by the river and vegetable garden, isolate two efficient cellulolytic bacteria N2 and M8 by enrichment culture, Congo red culture medium, filter paper degradation rate determination, shake-flask culture and determination of the enzyme activity(CMCase). Then make the molecular biology identification and identify the N2 belongs to Lysinibacillus fusiformis, the M8 belongs to Staphylococcus sciuri.Cellulose degrading bacteria react with cellulose degradation by producing cellulase. In this study, the factors affect L. fusiformis, S. sciuri enzyme production conditions were studied after the screening. Results show that under the condition of the culture medium carbon source for the bran, two strains of bacteria produce higher enzyme activity. When medium nitrogen source was peptone and yeast powder, L. fusiformis and S. sciuri will produce more active enzyme. The best optimum temperature for L. fusiformis and S. sciuri's enzyme production is 20 ? and 25 ?, both of the temperature range is wide. When the initial pH of medium is 7.5, L. fusiformis enzyme production value is higher than other condition, for the S. sciuri, the optimal initial pH is 6.5, usually the initial medium pH range in 6 ~ 8 are beneficial to the enzymatic reaction. The study shows that the different metal ions on the enzyme production effects of two strains exists difference. For L. fusiformis, the Zn2+ and Fe2+ both can promote the production of enzyme in appropriate concentration, while the Ca2+ can hardly affect the activity of enzyme production and the Mg2+ has inhibitory effect on enzymatic reaction. For S. sciuri, the Fe2+ and Zn2+ both can be the activator and the effect is obviously, while the Mg2+ and Ca2+ have no significant effect on enzymatic reaction.The L. fusiformis and corncob had been chosen for the carbon release study. The corncob had been scanning electron microscope before and after the reaction and their lixivium had been three-dimensional fluorescence spectrum analysis to verify the cellulose degradation bacteria's influence of releasing carbon, carbon release rate and carbon release time of the corncob. The results show that the optimizing concentration of cellulose degradation bacteria can strengthen the ability of carbon-release of corncob carbon source, at the same time carbon release rate could be regulated and controlled according to the concentration, as well to extend the time of testing. After that, this study designed the CASS test in process system, the research is for the promotion of solid carbon source's ability and the effect of the reactor effluent by the cellulose degradation bacteria in the reactor. The results show that the reactor effluent quality had been improved and it had proof that cellulose degradation bacteria has great potential applications in the biological denitrification technology.