Microbiological Aspects of Penicillin

Open Access
Publisher Website
Google Scholar
Abstract
Antibacterial substances present in culture filtrates of Aspergillus niger YW, A. nidulans, A. oryzae TP, A. flavipes and Penicillium citreoroseum are either identical with, or closely related to, authentic penicillin produced by P. notatum. This was shown by solubility properties, thermostability, pH stability, antibacterial spectra against 18 bacteria, destruction by the enzyme penicillinase, and (in one instance) by efficacy in protecting animals against a lethal bacterial infection. Substrains superior in penicillin-producing ability to the parent culture of A. oryzae TP were isolated. A. oryzae TP grew and produced penicillin best at 37[degree]C; with the other fungi the optimum was 25[degree]C. A. nidulans grew at 37[degree]C. but produced no penicillin. P. notatum, A. niger, and P. citreoroseum did not grow at 37[degree]C. Kojic acid was more effective in inhibiting the gram-negative bacteria tested than the gram-positive ones.