ABSTRACT
PCR-DGGE(denaturing gradient gel electrophoresis) and clone library analysis combined with culture dependent isolation methods were used to analyze the population composition and its stability over different production batches of one commercial biofertilizer.DGGE fingerprinting showed that samples from the same production batch had 80%~100% similarity coefficient and those from different batches had 80%~88%,an indication that population composition of the biofertilizer was relative stable within the same batch and from batch to batch.Isolation followed with 16S rRNA clone library analysis showed that the microorganisms contained in the products were not in agreement with the product's label.Only Lactobacillus,one of the 6 microorganisms labeled in the products,was detected in the samples.Other bacteria detected with the two methods were Bacillus,Monascus,Brevibacillus,Psudomonas and Penicillium,which were not listed in the product's label.These results showed that molecular ecological methods may provide a new technology for quality control of biofertilizers.