Acta Pharm. 48 (1998) 139-144

Short communication  
 

Aflatoxigenicity of Rhizopus nigricans strains isolated from drug plants

STJEPAN PEPELJNJAK*   and   ZDENKA CVETNIC

Department of Microbiology, Faculty of Pharmacy and Biochemistry, University of Zagreb, 10000 Zagreb  
Received March 24,      1998 Accepted May 29, 1998

Mycological analyses of 64 samples of drug plants stored and collected from drugstores showed 50.0% of samples to be contaminated with Rhizopus nigricans.
Aflatoxigenicity of Rhizopus nigricans strains was assessed by specific fluorescence test in aflatoxin-producing ability medium (APA) (detection in UV at 365 nm) and by extraction after biosyntheses on yeast extract sucrose (YES) broth.
Aflatoxins were produced by 40% of strains. All of the aflatoxins-producing strains in YES showed intensive blue fluorescence in the APA-medium.
The strains of Rhizopus nigricans were producers of two aflatoxins: AFB1 and AFB2. The concentrations of aflatoxin B1 and aflatoxin B2 ranged from 1.22 to 1.33 and from 0.10 to 0.20 mg L-1 culture filtrate, respectively.
The results warn of the risk of improper storing and using drug plants with no previous evaluation of their quality in terms of mycotoxicological parameters.


Keywords: mycological contamination, drug plants, Rhizopus nigricans, aflatoxin B1, aflatoxin B2

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