Bioautographic Method Research Articles

Comparison of solvents and methods of extracting methylbenzimidazol‐2‐yicarbamate (MBC) from tobacco

AbstractThe bioautographic method of Homans and Fuchs for detecting MBC on thin layer plates, was tested quantitatively. The sum of the vertical and horizontal diameters of the zones of inhibition of Penicillium expansum, and the square root of the mass of an equal area of paper, were directly proportional to the logarithm of the concentration of MBC. Methanol and ethanol extracted significantly more MBC from tobacco tissue than acetone and chloroform. Soxhlet extraction was more effective than cold (22 °C) treatment, but the latter, in which 100 mg aliquots of dried tissue were used, was the least variable, very much quicker and could be used to detect the fungicide in small amounts of individual plant tissues.

<i>Lactobacillus arabinosus</i> 17-5の生産する葉酸様活性物質 (Factor-F) について

The syntrophism has been demonstrated between L. arabinosus 17-5 (ATCC 8014) and Sc. faecalis R (ATCC 8043) in a synthetic medium which lacked phenylalanine and folic acid. The growth mechanism of this syntrophic culture was explained in terms of the presence of two growth factors produced by both microorganisms. In this experiments, the growth factor (Factor-F) having an activity as folic acid for Sc. faecalis was studied. The factor was isolated from the broth of L. arabinosus cultured in a synthetic medium lacking folic acid by adsorption on active carbon followed by elution with ammoniacal ethanol. The resulting product was required for the growth of Sc. faecalis, L. casei ε (ATCC 7469; L. helveticus) and L. leichmannii (ATCC 7830; L. delbruekii) as a replacing factor of folic acid. A usual bioautographic method indicated that the factor was different from folic acid, vitamin B12, thymine and thymidine.

Biosynthesis of thiamine in plants. I. Enzymic formation of thiamine from pyrimidine and thiazole moieties.

To elucidate the biosynthetic pathway of thiamine in plants, the nature of the activation and condensation reactions of pyrimidine (2-methyl-4-amino-5-hydroxymethylpyrimidine) and thiazole (4-methyl-5, β-hydroxyethylthiazole) moieties were studied with cell-free extracts prepared from acetone powders of Japanese Radish and Rape. Investigations of the effects of preliminary incubation and of the early stage of the reactions using phosphorylated substrates suggested that both pyrimidine and thiazole had to be activated by ATP in the presence of Mg2+ before their condensation to form thiamine-P (thiamine monophosphate). The rate of thiamine-P synthesis in the presence of ATP and Mg2+ increased in the order of pyrimidine-PP>pyrimidine-P>pyrimidine in respect of pyrimidine moieties, and thiazole-P was more active substrate than thiazole. The nature of thiamine synthesized was determined as thiamine-P by the bioautographic method using a thiamine-less mutant of Lactobacillus fermenti. From these results it was concluded that thiamine-P in plants is synthesized through the pathway proposed in the cases of microorganisms.It was found that thiaminephosphate pyrophosphorylase (EC 2.5.1.3) activity was inhibited by ATP, ADP, and EDTA, and that the inhibition was reversed almost completely by the addition of Mg2+ of about the equimolar concentration as each of them.

Whole body sagittal technique in mice employing a new bio-autographic method: its utility for the evaluation of the body distribution of antibacterial drugs.

E stato studiato un metodo per lo studio della distribuzione di farmaci antibatterici basato sull'insemenzamento diretto con svariati germi di sottili sezioni longitudinali di topo previamente trattato con antibatterici; la presenza di germe vivo viene rilevata per mezzo di una colorazione vitale con il cloridrato di 2,3,5-trifeniltetrazolio.

A bioautographic method for identification of choline and its derivatives

A sensitive and specific bioautographic method for detecting choline and its derivatives has been developed, utilizing a Neurospora crassa mutant. As little as 0.03 μg of choline chloride is detectable. The applicability of the method for detection of choline derivatives in lipid hydrolyzates is discussed. A method for determining the rate of diffusion of compounds from paper chromatograms into bioautograph agar is described.

A bioautographic method for the identification of inositol and inositol phosphate

A bioautographic method, utilizing Saccharomyces carlsbergensis strain 4228, was shown to be capable of detecting and distinguishing between myoinositol, myoinositol 2-phosphate, and other derivatives of myoinositol. The method was shown to respond to as little as 1 μg inositol and is effective even in the presence of lipid hydrolyzates. A discussion of the applicability of the method to the detection of inositol and its derivatives in lipid hydrolyzates and other natural materials is included.