A Comparative Study on the Biofilm Formation of Enterobacter agglomerans and Serretia rubideae in Different Environmental Parameter under Single Culture Condition

摘要

The biofilm formation by two opportunistic pathogens Enterobacter agglomerans and Serretia rubideae on different environmental parameter under single culture condition was compared. Biofilm clone formation unit (CFU) counting revealed that the number of Enterobacter was larger than Serretia after 24-h incubation. Consistent with this result, measurement of crystal violet staining of bacteria attached on the test tubes showed that the absorbance at 600 nm enhanced 2 times in Enterobacter than Serretia under optimum growth condition. Experiments with different environmental conditions such as incubation period, temperature, pH, NaCl concentration (aw) and medium ingredient contents for both organisms were carried out in Luria Bertani (LB) broth. The results indicated that Enterobacter grew well at 37?C after 24 h but Serretia grew well at 27?C after 48-h and 0.5% NaCl concentration was found optimum for both. On the other hand, 0.5% medium content and pH 5 was found optimum for Enterobacter whereas 2% medium content and pH 7 for Serretia.