Abstract:To obtain mutants with high threonine productivity, atmospheric and room temperature plasmas (ARTP) mutation technique was used and combined with high throughput screening based on 48 well plates. Mutant 1905# was screened with high threoine productivity. Compared with original strain under the same fermentation conditions, the mutant 1905# showed better robustness and faster growth rate. The mutant showed similar optimum temperature (37 ℃) and pH (7.2) to the original strain, but it can tolerate lower pH. In the preliminary plate screening, the threonine concentration increased by 133.59%. For the flask fermentation process, the mutant 1905# showed higher glucose consumption and enhanced threonine productivity The threonine concentration by the mutant was increased by 99.6% compared with that by the original. The 1905# mutant showed high genetic stability after 50 subcultures, offering theoretical reference for further increasing threonine industrialization level
