title: Coexistence of and interaction relationships between an aflatoxin-producing fungus and a bacterium.
abstract: The interactions between aflatoxin-producing fungi and bacteria have opened up a new avenue for identifying biological agents suitable for controlling aflatoxin contamination. In this study, we analysed the interactions between A. flavus and the bacterium Burkholderia gladioli M3 that coexist in rice that is naturally contaminated with A. flavus. Our results showed that a cell-free culture filtrate (CCF) and the metabolite bongkrekic acid of the M3 strain potently suppressed the mycelial growth and spore production, and then affected the production of aflatoxin of A. flavus. Bongkrekic acid secreted by the M3 strain exhibited higher antifungal activity than did analogues. The CCF of the M3 strain and its metabolite bongkrekic acid can inhibit the growth of A. flavus, but the metabolites of A. flavus, aflatoxins, exerted no inhibitory effect on the growth of the M3 strain. Furthermore, we determined that the M3 cells could use the dead mycelia of A. flavus as energy sources for reproduction, while A. flavus could not grow in a solution containing dead M3 cells. In summary, these results indicated that B. gladioli has a competitive advantage in survival when it coexists with its fungal partner A. flavus.
authors.affiliation: Key Laboratory of Aquatic Product Safety (Sun Yat-sen University), Ministry of Education, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China; Guangdong Institute for Food and Drug Control, Guangzhou 510180, China.
authors.forename: Quan-Hong
authors.initials: QH
authors.lastname: Yan
authors.affiliation: Key Laboratory of Aquatic Product Safety (Sun Yat-sen University), Ministry of Education, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.
authors.forename: Jian-Xiang
authors.initials: JX
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Aquatic Product Safety (Sun Yat-sen University), Ministry of Education, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.
authors.forename: Hong-Zhou
authors.initials: HZ
authors.lastname: Li
authors.affiliation: Key Laboratory of Aquatic Product Safety (Sun Yat-sen University), Ministry of Education, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.
authors.forename: Qing-Qing
authors.initials: QQ
authors.lastname: Zhi
authors.affiliation: Department of Oncology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China. Electronic address: xiaodaosui@126.com.
authors.forename: Xiao-Ping
authors.initials: XP
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Aquatic Product Safety (Sun Yat-sen University), Ministry of Education, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China. Electronic address: lsshezm@mail.sysu.edu.cn.
authors.forename: Zhu-Mei
authors.initials: ZM
authors.lastname: He
mesh_terms: D000348:Aflatoxins / Q000378:metabolism*; D001231:Aspergillus flavus / Q000254:growth & development / Q000378:metabolism*; D001865:Bongkrekic Acid / Q000378:metabolism; D042725:Burkholderia gladioli / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism*; D012275:Oryza / Q000382:microbiology*
chemical_list: D000348:Aflatoxins; D001865:Bongkrekic Acid
keywords: Aspergillus flavus; Bongkrekic acid; Burkholderia gladioli; Coexistence; Fungal–bacterial interaction