Dibutyl phthalate, the bioactive compound produced by Streptomyces albidoflavus 321.2.

A quantitative microbiological assay and a bioautography system with Penicillium avellaneum UC-4376 was developed for the antitumor drugs maytansine, and its homologues, maytanprine and maytanbutine. The susceptibility of the assay is 1.5 μg/ml.

Microbiological assays and bioautography of maytansine and its homologues.

SYNOPSIS

Drug sensitivities of a lower trypanosomatid, Leptomonas sp. from the hemipteran Dysdercus, to antitrypanosomatid agents were estimated by growth inhibition and inhibition of polarographically measured O2 uptake of cells and particulate fractions. Several standard trypanocides, antimalarials, and electron-transport inhibitors were used. Acriflavine, quinacrine, primaquine, pentamidine, and ethidium, each at ∼1 mM, inhibited cellular O2 uptake by 50% after 3-hr incubation. Suramin and melarsen were inactive. Crude particulate fractions oxidized L-α-glycerophosphate at 80% the rate of succinate oxidation and L-proline at 55% the succinate rate, leading to choice of succinate as standard respiratory substrate. Concentrations for 50% inhibition of growth were (μg/ml): ethidium bromide 0.009, acriflavine HCl 0.12, Antrycide 0.83, pentamidine diisethionate 1.5, and stilbamidine isethionate 1.1. Possible use of this trypanosomatid as model organism for screening antitrypanosomatid agents, and use of ethidium and acriflavine as initial model compounds are discussed.

Inhibition by several standard antiprotozoal drugs of growth and O2 uptake of cells and particulate preparations of a Leptomonas.

Screening for anti-HIV drugs that can combine virucidal and virustatic activities synergistically.

A new antitumor antibiotic, U-43,120 was discovered. It is produced by fermentation of a new species of Streptomyces, designated Streptomyces paulus DIETZ sp. n. Its antimicrobial activity is limited to bacteria. A microbiological assay with Bacillus subtilis was developed that can be detect concentrations of 1 approximately 2 mug/ml of the drug in fermentation liquors. U-43,120 was active in vivo against P-388 leukemia in mice.

U-43,120; a new antitumor antibiotic. I. Production, biological activity, microbiological assay and taxonomy of the producing microorganism.

Publisher Summary This chapter describes the technique of correlative assays The correlative assays are used quite frequently to monitor the titers of fermentation liquors during culture development and during the isolation process The first step in the development of a correlative assay involves the testing of the compounds of interest against a broad spectrum of different microorganisms If a strong enough activity is found, a correlative microbiological assay can be developed to replace the original assay The chapter presents a list of microorganisms used in the correlative testing program and summarizes the specific cultivation conditions for each of the microorganisms used in the program A specific example is used to demonstrate the method of establishing the correlation between the primary biological activity and the correlative antimicrobial activity The most sensitive among the microorganisms used in this program appears to be Lactobacillus casei It is inhibited by more than 50% of the samples tested The next most sensitive microorganism was Bacillus subtilis, particularly when cultivated in a completely synthetic growth medium The chapter also discusses several advantages of microbiological assays

Hanka Lj

Papers

Correlative microbiological assays.