High-throughput Screening For High Salinomycin Yield Strain And Oil Feeding Strategy For Salinomycin Production

Salinomycin is a kind of polyether antibiotics used in poultry,which has several advantages like anti-coccidiosis,promoting growth and killing tumor cells.At the same time,salinomycin as one of anti-cancer drugs has attracted many attentions with huge potential market in the future.Although salinomycin fermentation industry has been developed,high-yield strains and high efficient fermentation process development are still needed.1.Strain improvement using an integrated method of ARTP,genome shuffling and high through-put screening.In this study,high-throughput screening technology and mutagenesis technology including ARTP and Genome Shuffling are used to improve strains for salinomycin production.Firstly,5 high-yield mutants were obtained after ARTP mutagenesis.Then they was used as original strains for genome shuffling,3 mutants were screened after three rounds of protoplast fusion.Compared to genome shuffling,the ARTP is more suitable for use in factory due to its simple and convenient operation.However,genome shuffling is more suitable for research laboratory with strict operation.2.In order to develop a more convenient,rapid and unpretreated method to measure the oil content in the culture medium,a quantitative determination of oil content in fermentation broth using LF-NMR instrument has been developedThe results were showed as follows:the relaxation time of oil is about 100 ms after all components of the medium were detected-using low field-NMR(LF-NMR)technology.No ingredients except for soybean flour and wheat germ flour can affect oil peak area in the single factor experiments.The oil content determined by LF-NMR teste showed that it has a good stability(CV=4.4%)and accuracy of about 1.0%.In addition,the oil contents obtained using both N-hexane extraction and LF-NMR technology presented a linear relationship with a correlation of R2=0.9581.Therfore,LF-NMR method could be applied in the industrial process to monitor oil content in the broth.3.The established LF-NMR method was successfully applied to control oil content in salinomycin fermentation process.Spectrometric method could not detect different oil concentration samples.n-hexane extraction can roughly determine the oil samples with difference from the theoretical values.However,LF-NMR has advantages such as high accuracy and easy sample treatment over spectrometric method and n-hexane extraction.Based on LF-NMR technology,constant feeding mode and fed-batch mode were applied to oil monitoring and control process.Using the fed-batch strategy,growth promotion of salinomycin-producing strains cells was observed to maintain salinomycin formation rate,resulting in high sailinomycin yield.