A. C. Kirpekar

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A mixed microbial culture capable of growing aerobically on tetrahydrofuran (THF) as a sole carbon and energy source was used as the inoculum in a 10 l working volume membrane bioreactor. Following start-up, the reactor was operated in batch mode for 24 h and then switched to continuous feed with 100% biomass recycle. On average, greater than 96% of THF fed(More)
A lovastatin-hyperproducing culture ofAspergillus terreus was shown to produce several co-metabolites extracted from whole broth. The predominant co-metabolite was the benzophenone, sulochrin, reported to arise from a polyketide biosynthetic pathway. This compound was targeted for elimination by classical mutagenesis and screening. A surface culture method(More)
An efrotomycin fermentation was characterized through physical, chemical and biochemical studies. Growth of the actinomycete,Nocardia lactamdurans occurred during the first 50 h of the fermentation cycle at the expense of glucose, protein, and triglycerides. The initiation of efrotomycin biosynthesis was observed when glucose dropped to a low concentration.(More)
A High cephamycin C producing strain of Nocardia lactam-durans was used to study cell growth and antibiotics production in defined media. Batch fermentations in shake flasks and stirred tanks showed that antibiotic production occurred during cell growth and the production rate rapidly decline as the growth slowed. Glutamate served as a primary substrate(More)
Efrotomycin is a modified polyketide antibiotic of the elfamycin family that has use in the area of pig husbandry. Optimization of the fermentation medium for production of efrotomycin byNocardia lactamdurans revealed that the fermentation is sensitive to hard water and certain lots of cottonseed flour used to prepare a complex fermentation medium. A(More)
The reversion of a cephamycin C-producing strain of Nocardia lactamdurans to a non-producing variant under continuous culture conditions was examined at dilution rates between 0.025 and 0.045 hr(-1). A model incorporating the influence of revertants, when present in the culture in significant numbers, was necessary to adequately describe the dynamics of the(More)
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