The Screening,identification And Technology Optimization Of The Strains With The Biotransformation Ability From Baccatin ? To 10-DAB

Docetaxel is a typical semi-synthesis and structure-modified antitumor drug of taxanes,10-DAB is an important raw material which can be used to synthesize docetaxel.In recent years,the researchers found that microorganisms can produce 10-DAB by the conversion reactions of baccatin III,Microbial transformation reaction has selectivity,mild conditions,less environmental pollution,fast reaction rate,it makes biotransformation good prospects,however it is critical that the strains with the biotransformation of Baccatin III to 10-DAB are screened.In our previous work,42 strains have been isolated from the sludge of TEDA Sewage Treatment Plant.In this topic,we screen strains which have the ability of transforming baccatin III to 10-DAB from 42 strains.After screening,we choose the strains which can produce 10-DAB from baccatin III to identify and preliminary technology optimization.This study will lay the foundation for the new materials and methods of taxanes' biosynthesis.The results are as follows:(1)13 strains all have the ability of transforming bakatin III to 10-DAB.The product yield was in the range of 0.40%to 5.01%,the strain P2-A-8 was the highest,reaching 5.01%.(2)Based on physiological and biochemical features,16S rDNA sequence analysis and morphological characteristics,the strains which can transform baccatin III to 10-DAB.Final results of the strains were identified as:P2-A-1 was identified as Tolumonas osonensisa,P2-A-2 was identified as Acinetobacter baumannii,P2-A-3 was identified as Escherichia coli,P2-A-4 was identified as Pantoea sp.,P2-A-5 was identified as Kocuria rhizophila,P2-A-6 was identified as Aeromonas media,P2-A-7 was identified as Aeromonas hydrophila,P2-A-8 was identified as Pantoea agglomerans,P2-A-9 was identified as Aeromonas hydrophila,P2-A-10?P2-A-11?P2-A-12?P2-A-13 were identified as Pseudomonas aeruginosa.Among of them,Pantoea agglomerans is known microorganisms which can biotransform baccatin III to 10-DAB.Pseudomonas aeruginosa is known microorganisms which can biotransform taxol to 10-DAB.(3)The strain P2-A-8 which produce most 10-DAB was the research object,with Box-Behnken experimental design,conversion process for Baccatin III were studied.Optimized reaction conditions were cell incubation time 12 h,cell concentration OD600 3.0,substrate concentration 1.75 mg/mL,transition temperature 32 C,conversion time 4 d,the yield of 10-DAB reached to 24.5%,it was 446.8%more than the previous optimization.