title: Improving flavonoid extraction from Ginkgo biloba leaves by prefermentation processing.
abstract: This paper presents a prefermentation treatment method involving fungi to improve flavonoid extraction from the leaves of Ginkgo biloba . The fungi employed for this treatment were screened from the soil present under an ancient ginkgo tree. Seventy-six strains belonging to 23 genera were isolated and identified by a molecular identification method employing 18S rDNA sequences. Thirty-three strains grew well using ginkgo leaves as the growth medium. One strain, Gyx086, with higher extracted yield of flavonoids and more similar to the control, was finally selected for prefermentation processing. The major fermentation factors were optimized by response surface methodology. The optimal conditions for the highest total falvonoid yield were 27.8 °C for temperature, 64.2% for moisture content, and 61 h for fermentation time. Under the optimal condition, a actual total flavonoid yield of 27.59 ± 0.52 mg/g dry weight culture sample was obtained, which was about 70% higher than that of unfermented gingko leaf samples.
authors.affiliation: College of Forest Resources and Environment, ‡College of Light Industry Science and Engineering, and #College of Chemical Engineering, Nanjing Forest University , Nanjing 210037, People's Republic of China.
authors.forename: Jiahong
authors.initials: J
authors.lastname: Wang
authors.forename: Fuliang
authors.initials: F
authors.lastname: Cao
authors.forename: Erzheng
authors.initials: E
authors.lastname: Su
authors.forename: Caie
authors.initials: C
authors.lastname: Wu
authors.forename: Linguo
authors.initials: L
authors.lastname: Zhao
authors.forename: Ruifeng
authors.initials: R
authors.lastname: Ying
mesh_terms: D000975:Antioxidants / Q000032:analysis / Q000302:isolation & purification*; D002681:China; D019587:Dietary Supplements / Q000032:analysis; D005240:Feasibility Studies; D005285:Fermentation; D047309:Flavones / Q000032:analysis / Q000302:isolation & purification*; D005658:Fungi / Q000145:classification / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism*; D020441:Ginkgo biloba / Q000737:chemistry* / Q000254:growth & development / Q000382:microbiology; D006868:Hydrolysis; D008031:Lignin / Q000032:analysis / Q000378:metabolism*; D058889:Molecular Typing; D016533:Mycological Typing Techniques; D018515:Plant Leaves / Q000737:chemistry* / Q000254:growth & development / Q000382:microbiology; D012988:Soil Microbiology; D013045:Species Specificity
chemical_list: D000975:Antioxidants; D047309:Flavones; C036909:lignocellulose; D008031:Lignin