title: Isolation and screening of strains producing high amounts of rutin degrading enzymes from Fagopyrum tataricum seeds.
abstract: The rutin degrading enzyme (RDE) was isolated and purified from tartary buckwheat seeds. The RDE was purified about 11.34-fold and its final yield was 3.5%, which was very low, due to our purification strategy of giving priority to purity over yield. The RDE molecular weight was estimated to be about 60 kDa. When rutin was used as substrate, an optimal enzyme activity was seen at around pH 5.0 and 40 °C. Strains isolation strategy characterized by the use of rutin as sole carbon source in enrichment cultures was used to isolate RDE-producing strains. Then the active strains were identified by morphology characterization and 18s rDNA-ITS (Internal Transcribed Spacer) gene sequencing. Three isolates coded as B3, W2, Y2 were successfully isolated from fusty Fagopyrum tataricum flour cultures. Strain B3 possessed the highest unit activity among these three strains, and its total activity reached up to 171.0 Unit. The active isolate (B3) could be assigned to Penicillium farinosum. When the Penicillium farinosum strains were added to tartary buckwheat flour cultures at pH 5.0, 30 °C after 5 days fermentation, the quercetin production raised up to 1.78 mg/l, almost 5.1 times higher than the fermentation without the above active strains. Hence, a new approach was available to utilize microorganism-aided fermentation for effective quercetin extraction from Fagopyrum tataricum seeds.
authors.affiliation: College of Life and Basic Science, Sichuan Agricultural University, Yaan, Sichuan, People's Republic of China.
authors.forename: Ya-Di
authors.initials: YD
authors.lastname: Zheng
authors.forename: Qing-Lin
authors.initials: QL
authors.lastname: Luo
authors.forename: Mei-Liang
authors.initials: ML
authors.lastname: Zhou
authors.forename: De-Zhou
authors.initials: DZ
authors.lastname: Wang
authors.forename: Ye-Dong
authors.initials: YD
authors.lastname: Zhang
authors.forename: Ji-Rong
authors.initials: JR
authors.lastname: Shao
authors.forename: Xue-Mei
authors.initials: XM
authors.lastname: Zhu
authors.forename: Yu
authors.initials: Y
authors.lastname: Tang
mesh_terms: D001711:Biotransformation; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D004798:Enzymes / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D019612:Fagopyrum / Q000201:enzymology*; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D010407:Penicillium / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D012431:Rutin / Q000378:metabolism*; D012639:Seeds / Q000201:enzymology; D017422:Sequence Analysis, DNA; D013696:Temperature
chemical_list: D021903:DNA, Ribosomal Spacer; D004798:Enzymes; D012431:Rutin