title: Nematicidal Activity of Kojic Acid Produced by Aspergillus oryzae against Meloidogyne incognita.
abstract: The fungal strain EML-DML3PNa1 isolated from leaf of white dogwood (Cornus alba L.) showed strong nematicidal activity with juvenile mortality of 87.6% at a concentration of 20% fermentation broth filtrate at 3 days after treatment. The active fungal strain was identified as Aspergillus oryzae, which belongs to section Flavi, based on the morphological characteristics and sequence analysis of the ITS rDNA, calmodulin (CaM), and β-tubulin (BenA) genes. The strain reduced the pH value to 5.62 after 7 days of incubation. Organic acid analysis revealed the presence of citric acid (515.0 mg/kg), malic acid (506.6 mg/kg), and fumaric acid (21.7 mg/kg). The three organic acids showed moderate nematicidal activities, but the mixture of citric acid, malic acid, and fumaric acid did not exhibit the full nematicidal activity of the culture filtrate of EML- DML3PNa1. Bioassay-guided fractionation coupled with (1)H- and (13)C-NMR and EI-MS analyses led to identification of kojic acid as the major nematicidal metabolite. Kojic acid exhibited dose-dependent mortality and inhibited the hatchability of M. incognita, showing EC50 values of 195.2 µg/ml and 238.3 µg/ml, respectively, at 72 h postexposure. These results suggest that A. oryzae EML-DML3PNa1 and kojic acid have potential as a biological control agent against M. incognita.
authors.affiliation: Department of Agricultural Chemistry, Institute of Environmentally Friendly Agriculture, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Republic of Korea.
authors.forename: Tae Yoon
authors.initials: TY
authors.lastname: Kim
authors.affiliation: Department of Agricultural Chemistry, Institute of Environmentally Friendly Agriculture, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Republic of Korea.
authors.forename: Ja Yeong
authors.initials: JY
authors.lastname: Jang
authors.affiliation: Department of Agricultural Chemistry, Institute of Environmentally Friendly Agriculture, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Republic of Korea.
authors.forename: Sun Jeong
authors.initials: SJ
authors.lastname: Jeon
authors.affiliation: Department of Agricultural Chemistry, Institute of Environmentally Friendly Agriculture, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Republic of Korea.
authors.forename: Hye Won
authors.initials: HW
authors.lastname: Lee
authors.affiliation: Biological and Genetic Resources Assessment Division, National Institute of Biological Resources, Incheon 22689, Republic of Korea.
authors.forename: Chang-Hwan
authors.initials: CH
authors.lastname: Bae
authors.affiliation: Biological and Genetic Resources Assessment Division, National Institute of Biological Resources, Incheon 22689, Republic of Korea.
authors.forename: Joo Hong
authors.initials: JH
authors.lastname: Yeo
authors.affiliation: Department of Agricultural Chemistry, Institute of Environmentally Friendly Agriculture, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Republic of Korea.
authors.forename: Hyang Burm
authors.initials: HB
authors.lastname: Lee
authors.affiliation: Department of Agricultural Chemistry, Institute of Environmentally Friendly Agriculture, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Republic of Korea.
authors.forename: In Seon
authors.initials: IS
authors.lastname: Kim
authors.affiliation: World Institute of Kimchi, an Annex of Korea Food Research Institute, Gwangju 61755, Republic of Korea.
authors.forename: Hae Woong
authors.initials: HW
authors.lastname: Park
authors.affiliation: Department of Agricultural Chemistry, Institute of Environmentally Friendly Agriculture, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Republic of Korea.
authors.forename: Jin-Cheol
authors.initials: JC
authors.lastname: Kim
mesh_terms: D000818:Animals; D000969:Antinematodal Agents / Q000302:isolation & purification / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology*; D001236:Aspergillus oryzae / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D002147:Calmodulin / Q000235:genetics; D019343:Citric Acid / Q000032:analysis / Q000494:pharmacology; D029768:Cornus / Q000382:microbiology; D003470:Culture Media / Q000737:chemistry; D005285:Fermentation; D005650:Fumarates / Q000032:analysis / Q000494:pharmacology; D008293:Malates / Q000032:analysis / Q000494:pharmacology; D016133:Polymerase Chain Reaction; D011753:Pyrones / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D017422:Sequence Analysis, DNA; D014404:Tubulin / Q000235:genetics; D014431:Tylenchoidea / Q000187:drug effects*
chemical_list: D000969:Antinematodal Agents; D000975:Antioxidants; D002147:Calmodulin; D003470:Culture Media; D005650:Fumarates; D008293:Malates; D011753:Pyrones; D014404:Tubulin; D019343:Citric Acid; C011890:kojic acid; C030298:malic acid; C032005:fumaric acid
keywords: Aspergillus oryzae; Meloidogyne incognita; kojic acid; nematicidal activity