Abstract: A strain of red pigment fungi RJL03 (Monascus sanguineus) was isolated from the medicinal plant Rehmannia glutinosa Libosch by tissue block separation methd.Monascus sanguineus was identified according to morphological characteristics and rDNA ITS1-5.8S-ITS2 sequence analysis.Response Surface Methodology (RSM) was used to further improve the red pigment yield of RJL03 strain.On the basic of single factor tests,the strain was fermentation process of the liquid shake flask by using the Box-Behnken design (BBD),with the optical density of the fermentation broth as an index.The experiment manifests that the fermentation broth of pigment has its maximal absorption wavelength at 474 nm.The optimum fermentation conditions were as follows:temperature 30 ℃,bottling volume 67 %,initial pH natural (7).After the fermentation of the strain,optimization by RSM significantly increased the yield of the target strain.

Key words: Rehmannia glutinosa, endophytic fungi, red pigment, flask fermentation, Monascus, Monascus sanguineus