ANYL 171 |
| The agar diffusion bioassay technique for rapidly screening a large number of high-yielding strains from individual mutants was developed in natamycin fermentation. This method used Rhodotorula rubra AS 2.166 as a test organism and analytical conditions were as follows, sample volume: 70 µL, the test organism spore suspension concentration: 108 CFU/mL, the volume ratio between test organism spore suspension and upper medium: 1:10, cultivation time: 12h, temperature: 28°æ. Results showed that the relationship between the logarithm of natamycin content and the square of inhibitory zone diameter was linear in the concentration range of 0.2-1.2 g°¤L-1. The intra- and inter-day coefficient of variation (CV) were 0.42% (n=6) and 0.50% (n=6), respectively. The mean recoveries were 99.67%, 100.24% and 101.81% when the concentrations of spiked sample were 293, 586 and 1172 mg°¤L-1. Based on statistic analysis by ANOVA test, no significant difference was found between bioassay and HPLC methods with P<0.05. The microbiological assay is proved to be suitable for quickly determining the concentration of natamycin in fermentation broth and can be widely applied in selecting high-production isolates from enormous mutants. Compared with HPLC method, this approach is more simple, economical and less labor-intensive.
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General Papers
7:00 PM-9:00 PM, Sunday, 10 September 2006 Moscone Center -- Hall D, Poster
Division of Analytical Chemistry |