Studies in penicillin production by Penicillium notatum, in surface culture: 1. A preliminary study of the metabolism of carbon, nitrogen, sulphur and phosphorus.

An earlier report from these laboratories described the metabolism of carbon and nitrogen compounds by Penicillium notatum in surface culture (Hockenhull, 1946), and some references were made to the utilization of sulphur by this organism. Further work on the latter aspect seemed desirable, especially as penicillin is a sulphur-containing compound. It is the purpose of the present communication to describe these investigations. Previous work on the sulphur metabolism of moulds is limited and is mainly concerned with A8pergillu8 niger. Rippel & Behr (1936) showed that this fungus, when supplied with sulphates, liberated considerable quantities of organic sulphur compounds into the medium. M6thes (1938) showed that when cystine, cysteine or thioglucose was supplied sulphates appeared in the medium. M6thes also showed that the reduction of sulphate to organic sulphur was greater in presence of ammonia than in presence of nitrate. Steinberg (1941) showed that many inorganic sulphur sources were available for the growth of A. niger (e.g. sulphate, thiosulphate, etc.) and concluded that the mould removed sulphur from organic compounds via sulphoxylic acids. Woolley & Peterson (1937) demonstrated the accumulation of 'cyclic' choline sulphate (,-sulphatoethyltrimethylammonium betaine),