Mutation Of A Gordonia Strain And Study Of Its Carotenoids Production

Carotenoid are a kind of industrial products that are widespread used in naturalfood,cosmetics and so on.Because of its good physical properties as well as excellent dyeingeffect,more and more people pay a attention on the growing importance of the health of thehuman,and take it into food market. In previous work, the reascher of our lab has screened out astrain that produce carotenoid, and identified it as Gordonia.The bacteria has good performanceand has great potential of industrial, so we are prepared to do the following work.1) The starting strain was taked mutation breeding to increase their carotenoid production.Determine the conditions of ultraviolet and nitrosoguanidine composite mutagenesis as UVirradiation6min,1.0g/L NTG.And determined simultaneously of diphenylamine filter plateconcentration of500ug/L. Four the strains HBUY-102HBUY-107the HBUY-110HBUY-112were selected. Their pigment production has increased by22%-25%, and has a good geneticstability.It shows that mutagens is effective.2) Lysing process and extraction solvent of Gordonia were selected, and take L9（34）orthogonal design to optimize pigment extraction.The results show that best lsing method isutrasonic wave and best oganic solvents is DMSO. The best optimization scheme was1h,25oC,and solid to liquid ratio is1:20. The eluent of the column chromatography are petroleum ether,acetone, and ethanol. ComponentⅠandⅡwere obtained,and componentⅡcontained purposedpigment. Further separation and purification of component II through the efficient preparationof chromatography, detect the pigment by HPLC.Its purity reach to95%.3) Purified pigment of Gordonia was analysised and identified.The method contained UVspectra, chemical functional groups to test the IR spectra, liquid mass spectrometric analysis.The results showed that this carotenoid neither contain carotennoids5,6or5,8-Epoxides norcarbonyl group, its molecular weight is552and molecular formula is C40H520,and it has13conjugated carbon-carbon double bonds, and one hydroxyl, preliminary identification of thiscarotenoid is lycoxanthin.4) The stability of the pigment qualitative was studied.The results showed that temperaturehas a greater impact on the stability of the pigment,and it was suitable saved in4℃.Underacidic conditions has damaging effects on the stability of the carotenoid, and appropriate pH is4. The oxidant and reductant are carotenoids have some role in the destruction, on the stabilityof the pigment some protection to do with K⁺、Na⁺、Ca²⁺、Mg²⁺、Gu²⁺、Zn²⁺、Fe³⁺. Fe²⁺enables a large number of oxidized pigment, the pigment should avoid it.