Microbial Degradation Of Lignite And Study On Its Fulvic Acid

Fulvic acid is a kind of complex compounds extracted from lignite or peat, it has wide range of application in industry, agriculture, animal husbandry, it also has a good development prospects in medicine and health food. FA has a variety of extraction methods, the FA used in medicine and health food research is extracted by chemical. But the chemical characteristics and physiological activity of FA will be destroyed in chemical. The main reason is that in the process of chemical extraction acid or alkali is added which could release heat during the reaction. Thus the temperature exceeds the optimum activity of fulvic acid60℃, FA of large molecular weight is get from chemical extraction which is more harmful substances, not easy to be absorbed by the body and sustainability of the resources.In this paper, isolation and screening of a strain Rhizopus No.7-A-2have better degradation ability of lignite from13strains of hybrid strains, This strain of Eshan, Xundian and Zhaotong microbial fermentation of lignite extraction, the fermentation conditions were optimized through the single factor analysis method, The optimum fermentation condition for Eshan lignite is:4d fermentation,28℃fermentation,6%inoculation,160r/min shaking; the optimum fermentation condition of Xundian lignite is:6d fermentation,28℃fermentation,10%inoculation,170r/min shaking; the optimum fermentation condition of Zhaotong lignite is:4d fermentation,28℃fermentation,10%inoculation,150r/min shaking.According to the above conditions, the different FA which from three producing area were extracted using the method of microbial direct extraction, microbial pretreatment extraction, and the chemical extraction, respectively. The FA yield analysis showed that, microbial direct degradation of Eshan lignite got the highest yield.9kinds of FA carried on the preliminary chemical characteristics and physiological activity (antioxidant and anti-inflammatory) comparative analysis. Chemical properties showed that FA water-soluble became better after the microbial treatment, its pH was closed to the neutral, its molecular weight decreased, the flocculation limit got higher, more conducive to absorb, C elements increased, O elements reduced, phenolic hydroxyl increased, carboxyl decreased, active functional groups increased, and infrared spectrum analysis showed that the three methods for making the FA have similar infrared spectrum. Physiological characteristics showed that9kinds of FA had both the oxidation resistance and the anti-inflammatory. Moreover, the effect of antioxidant and anti-inflammatory effects of FA have improved significantly after microbial treatment.