The fungistatic properties of p-aminobenzoic acid and related compounds. Part I. Growth curves obtained withaspergillus niger, penicillium roquefortiandbyssochlamys fulva
✍ Scribed by Cavill, G. W. K. ;Vincent, J. M.
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1948
- Weight
- 866 KB
- Volume
- 67
- Category
- Article
- ISSN
- 0368-4075
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✦ Synopsis
A. ,tiger, growing in the presence of p-aminobenzoic acid and its lower alkyl esters, departs significantly from linearity in media of approximate pH 3 to 5, containing nitrate nitrogen. This effect is not observed where media are of p , ~ 6 to 7 or nitrogen is supplied solely as the ammonium ion or the free pora-amino grouping is acetylated or with the corresponding orrlio-or mera-aminobenzoatc. The non-linear growth rates can be interpreted in terms of an initial phase, a phase of secondary inhibition and a pericd of outgrowth. Inhibition in the initial phase is apprccinbly less at higher ~1 % levels. P. rogrrejorri growing in the presence of estcrs of p-aminobenzoic acid in media whcre p,, rises during growth shows an accelerating curve. This effect is associatedwith amarkedloss of inhibitory power at pH greater than about 5.7. A similar acceleration is seen with methyl N-acctyl-p-aminobenzoatc but has not been found with methyl p-hydroxybcnzcate. None of the free aminobenzoic acids departs from the linear growth curve with this organism.
B./ulro give3 an acceleration in the presence of methyl p-aminobenzoate under the same conditions of pH and nitrate nitrogen as cause secondary inhibition of A. niger. In contrast to thc other two organisms the lcss acid media (prt 5 and 7) arc relatively more inhibitory, this being associated with abscncc of acceleration such as is seen unde? the more acid conditions. The three aminobenzoic acids give linear growth curves.