Laverne Dwaine Boeck

A83543A-D, unique fermentation-derived tetracyclic macrolides

Abstract A multi-factored complex of structurally-unique macrolides was isolated from culture broths of a new species of Saccharopolyspora. The core structure consists of a 5,6,5-cis-anti-trans-tricyclic ring system fused to a 12-membered macrocyclic lactone, which is further substituted by an amino- and a neutral sugar.

On the biosynthesis of the antibiotic vancomycin

In the biosynthesis of vancomycin by Streptomyces orientalis it has been shown that di-m-hydroxyphenylglycine can be derived from acetic acid, whereas p-hydroxyphenylglycine and m-chloro-β-hydroxytyrosine are derived from tyrosine.

Sterilization of bioreactor media on the basis of computer calculated thermal input designated asF0

SummaryIndustrial fermentation media are normally sterilized with steam to destroy the indigenous microbial population prior to inoculation with a specific microorganism. Because biological validation of each sterilization cycle is impractical, an ‘overkill’ approach is commonly employed on the basis that alteration of heat-sensitive nutrients is less detrimental than survival of indigenous microbes. However, the heat destruction of microbes is known to be a probability function amenable to calculation. A computer has been programmed to calculate the on-line heat input asF0 values during sterilization of media in stirred bioreactors. The accumulation ofF0 values is then announced verbally to bioreactor operators by a communications controller with voice synthesizer.

Interaction of media components during bioreactor sterilization: definition and importance of R0

SummarySterilization of bioreactor media, to destroy viability of the indigenous microbial population, is normally accomplished by autoclaving, or heating with pressurized steam. However, simultaneous chemical changes in media can also be expected to result from the high temperatures. A kinetic procedure involving on-line computer calculation of heat input, designated asF0 values, was previously developed to estimate sterility achievement. A similar kinetic procedure, based on a general purpose Arrhenius ‘pseudo’ rate equation and designated asR0 values, has now been designed to evaluate, and control the effects of temperature and heating time on chemical reactions occurring in the media. Data are presented indicating thatR0 may be a useful parameter for reducing variability in culture metabolism and ‘scale-up’ when these variations result from different nutrient concentrations produced by non-standard heating during media sterilization in stirred bioreactors.

Deacetoxycephalosporin C from Streptomyces and fungi

A new metabolite produced by two species of Streptomyces and twenty two strains of fungi, is identified as deacetoxycephalosporin C.