The Micro-cultivation of Natamycin-producing Strains for Rapid Screening

Abstract:

As natamycin-producing strain, Streptomyces gilvosporeus was studied to develop the micro-cultivation system in 96 deep-well microplates for rapid screening from a large number of isolates. Firstly, the stainless steel cover perforated with holes and dressed with eight gauzes was designed to solve water evaporation and cross-contamination in 96 deep-well microplates. The optimal conditions for micro-cultivation were as follows: culture volume 600 μL, shaking speed 300 r/min, shaking diameter 40 mm, and the pattern of microbial growth and natamycin biosynthesis with the above micro-cultivation mode was quite similar with that in shake flasks. It was found that the maximum intra- microplate and inter-microplate difference were 1.93% and 6.62%, respectively. Using the statistic software analysis, the productivity in 96 deep-well microplates were in good linear correlation with those in shake flasks (F = 39.303, P = 0.00 < 0.01) and the rank of production distribution in two different cultivation systems was consistent. Therefore, the micro-cultivation in microplates was proved to be good standardization and parallelization, which was potential to be applied in rapid screening from a large number of strains.

Key words:Rapid screening, Micro-cultivation, Natamycin, Streptomyces gilvosporeus, Deep-well microplate