Three strains of Aspergihs versicolor were isolated from soil, obtained in pure culture, and grown with atropine sulfate as the sole source of carbon and nitrogen.
Optimum growth was obtained at 2 5 O , when cultures were aerated by continual shaking, and were buffered to pH 5.5 with 0.2 to 0.4 M phosphate. Optimal media contained 1.25 per cent atropine sulfate and were supplemented with vitamins and minerals. Growth rate was inhibited by higher substrate levels. Peak growth was attained in 5 days, following a &day lag period.
LTHOUGH atropine is toxic for many micro-A organisms, microbial growth often is observed in aqueous solutions of the alkaloid.
Little is known of the contaminating organisms, of other organisms capable of utilizing this alkaloid, or of the degradative pathways that are involved.
An organism that utilized atropine, hyoscyamine, scopolamine, tropine, or tropionone as sole carbon and nitrogen sources was first reported by Bucherer (l), who classified i t as Corynebacterium belladonnae (Nov. spec.).
Eighteen years later, phenylacetic acid and tropic acid were isolated from the growth medium, and the presence of atropinesterase was reported (2). In the intcrim, Kaczkowski ( 3 ) had reported that Arthrobacter terregens produced tropine, nortropine, tropic acid, and atropic acid, when grown with atropine as the sole source of carbon and nitrogen. Niemer (2) also isolated atropic acid during his studies with C. belladonnae, but only traces were obtained. He reasoned that atropic acid arose b y dehydration during isolation and was an artifact rather than a metabolite of atropine.
IJsing complete disappearance from the growth medium as the criterion for degradation, Kedzia and co-workers (4) surveyed 744 strains for ability to degrade atropine. Fifty-four strains, one of which was a n Aspergillus, degraded the alkaloid. In all instances, ability to degrade
atropine was an unstable property that was reacquired when the organism was subcultured 7 tu 15 times in a meat broth rncdium that contained atropinc.
From a soil sample, the authors have isolated pure cultures of three strains of Aspergillus that utilize atropine as a sole source of carbon and nitrogen. The authors intend to use these strains in studies of atropine metabolism and as a source of atropine-degrading enzymes. This