title: Detoxification of Jatropha curcas kernel cake by a novel Streptomyces fimicarius strain.
abstract: A huge amount of kernel cake, which contains a variety of toxins including phorbol esters (tumor promoters), is projected to be generated yearly in the near future by the Jatropha biodiesel industry. We showed that the kernel cake strongly inhibited plant seed germination and root growth and was highly toxic to carp fingerlings, even though phorbol esters were undetectable by HPLC. Therefore it must be detoxified before disposal to the environment. A mathematic model was established to estimate the general toxicity of the kernel cake by determining the survival time of carp fingerling. A new strain (Streptomyces fimicarius YUCM 310038) capable of degrading the total toxicity by more than 97% in a 9-day solid state fermentation was screened out from 578 strains including 198 known strains and 380 strains isolated from air and soil. The kernel cake fermented by YUCM 310038 was nontoxic to plants and carp fingerlings and significantly promoted tobacco plant growth, indicating its potential to transform the toxic kernel cake to bio-safe animal feed or organic fertilizer to remove the environmental concern and to reduce the cost of the Jatropha biodiesel industry. Microbial strain profile essential for the kernel cake detoxification was discussed.
authors.affiliation: Yunnan Institute of Microbiology, Yunnan University, Kunming 650091, China.
authors.forename: Xing-Hong
authors.initials: XH
authors.lastname: Wang
authors.forename: Lingcheng
authors.initials: L
authors.lastname: Ou
authors.forename: Liang-Liang
authors.initials: LL
authors.lastname: Fu
authors.forename: Shui
authors.initials: S
authors.lastname: Zheng
authors.forename: Ji-Dong
authors.initials: JD
authors.lastname: Lou
authors.forename: José
authors.initials: J
authors.lastname: Gomes-Laranjo
authors.forename: Jiao
authors.initials: J
authors.lastname: Li
authors.forename: Changhe
authors.initials: C
authors.lastname: Zhang
mesh_terms: D000818:Animals; D001673:Biodegradation, Environmental; D056804:Biofuels; D002347:Carps; D005285:Fermentation; D018525:Germination / Q000187:drug effects; D007220:Industrial Waste; D031286:Jatropha / Q000633:toxicity*; D007814:Larva / Q000187:drug effects; D008962:Models, Theoretical; D010703:Phorbol Esters; D018517:Plant Roots / Q000187:drug effects; D012037:Refuse Disposal / Q000379:methods*; D012639:Seeds / Q000187:drug effects; D013302:Streptomyces / Q000378:metabolism*; D013997:Time Factors
chemical_list: D056804:Biofuels; D007220:Industrial Waste; D010703:Phorbol Esters
keywords: Biodiesel; Jatropha curcas; Kernel cake detoxification; Solid state fermentation; Streptomyces fimicarius YUCM 310038