Screening and identification of cellulase producing nitrogen-fixing bacillus

In order to screen cellulase producing efficient nitrogen-fixation bacilli as bio-fixing bacteria for industrial manufacture,the soil suspension in the 80℃ water-bath for 10min,was enriched and isolated cultivation by nitrogen-free microcrystalline cellulose culture.DNS method and micro Kjeldahl method were used to determine the cellulose activity and nitrogen fixation efficiency.Inoculation effect was tested with cucumber potted experiment.Strain identification was carried out based on the morphology,physiology,biochemical test and 16SrDNA sequences analysis.The cellulase producing nitrogen-fixation bacillus CX21with growing quickly,relative high cellulase activity and N-fixation efficiency,was isolated.Besides,the strain could reach the equivalent effect of chemical nitrogen fertilizer.The identification results showed that the strain belong Paenibacillus mucilaginosus.