Species Identification of Industry Spoilage Microorganism and the Resistance Analysis

Abstract:

In the aim of preventive microorganism resistance to industrial biocides, a collection of microorganism which isolated from industry production and raw material were gathered. To characterize bacteria species according to Manual of Systematic and Determinative Bacteriology, API Identification System, 16S rDNA genes analysis, and fungus according to Manual for the Identificati of Fungi, 18S rDNA genes analysis, respectively. The minimum inhibitory concentrations for biocides were determined to estimate the microorganisms resistance. It was found that the majority of isolates in the collection were Gram-negative bacteria (46.91%) including genera Pseudomonas, Enterobacter, Aeromonas, Klebsiella and Burkholderia. The dominant strains of Gram-positive bacteria (32.71%) were genera Bacillus, Microbacterium, Arthrobacter, Listeria along with several coccus. And fungi (12%) were Aspergillus, Trichoderma and Penicillium. The value of MICs showed that main resistant species is Pseudomonas (33.78%), its average level of resistance was up to 36 mg/L and the resistance of stability was weak with subculture. The result indicated that one of the considerable reasons of biological pollution in industry was the microorganism tolerance and the nature of the membrane structure and the biofilm formation of bacteria probably played a important role in the formation of microorganism resistance.