Emmett W. Bassett

The biosynthesis of patulin. I. Related aromatic substances from Penicillium patulum, strain 2159A.

Abstract A non-pigmented mutant strain of Penicillium patulum excretes a variety of aromatic substances into the fermentation medium. In addition to gentisic acid, gentisaldehyde, 6-methylsalicylic acid, and patulin, already known in this species, this microorganism forms 6-formylsalicylic acid, 3-hydroxyphthalic acid and pyrogallol. Anthranilic acid and p -hydroxybenzoic acid were also detected chromatographically. The properties of several other isolated but as yet uncharacterized materials designated as “pre-patulin”, “292 mμ”, and “322 mμ” compounds have been described.

The biosynthesis of patulin: II. The general physiology of several strains of Penicillium patulum

Abstract The sequence of appearance of aromatic intermediates on the pathway toward patulin biosynthesis in several closely related strains of Penicillium patulum has been examined. Both growing cultures and the replacement method have been used in these experiments. A scheme whereby glucose gives rise to patulin via 6-methylsalicylic acid, 6-formylsalicylic acid, the gentisic series, and “pre-patulin” has been proposed. Based upon the finding of pyrogallol in the growth media, and on the fact that shikimic acid yields p -hydroxybenzoate in replacement cultures, it is suggested that two pathways toward aromatization coexist in these microorganisms.

Purification of Antibody to Galactosyl-Protein Conjugates

A rapid procedure for purification of rabbit antibody to β-D-galacto-sylphenylazo-bovine serum albumin is described. Antibody was precipitated with a heterologous antigen and was then dissociated from the precipitated complex with hapten. The antigen was partially removed by pH adjustment, and antibody was separated from residual antigen and from hapten by partition chromatography on Sephadex G-25. The antibody, obtained in 50 to 55 percent over-all yield, was 96 percent reactive with homologous antigen. It appeared to consist, of 95 percent of a single component, based upon physicochemical measurements.

Environmental factors relating to tropolone formation by Penicillium stipitatum

Abstract The formation of stipitatic acid and other aromatic and troponoid metabolites during growth of Penicillium stipitatum under various conditions has been examined. The chemical and physical properties of several of these presumptive additional tropolone derivatives are described. The efficiency of incorporation of carbohydrates, of aromatic compounds, and of tricarboxylic acid cycle intermediates into stipitatic acid and into a class of substances entitled “acetate replacement” compounds, by the replacement technique, has been ascertained. The results of some preliminary isotopic tracer experiments have also been presented. The relationship of these findings to aromatic ring biosynthesis has been discussed.