The extracellular enzymes of Coniophora cerebella

1. The extracellular enzymes present in the culture filtrates of Coniophora cerebella grown on various carbohydrate carbon sources were investigated. Enzymes that degraded cellulose derivatives, hemicellulose fractions, starch, laminarin, pectin and several oligosaccharides were detected. 2. All the polysaccharide-degrading activities were adaptive except for that acting on laminarin. 3. The culture filtrates degraded native cellulose to only a very limited extent. 4. The hemicellulase activity included enzymes acting on all the major components of wood hemicellulose. 5. The main starch-degrading enzyme was a glucoamylase. 6. Laminarin-degrading activity was produced when cellulose, hemicellulose or starch was used as carbon source for the fungus and it may be involved in the re-utilization of hyphal carbon or of a reserve polysaccharide synthesized during active growth of the organism.     

The metabolism of [2-14C]indole in the rat

1. [2-¹⁴C]Indole has been synthesized from [¹⁴C]formate and o-toluidine via N[¹⁴C]-formyltoluidine. 2. When fed to rats, the ¹⁴C of [¹⁴C]indole (dose 70–80mg./kg. body wt.) is fairly rapidly excreted, and in 2 days an average of 81% appears in the urine, 11% in the faeces and 2·4% as carbon dioxide in the expired air. 3. Radioactivity is excreted in the urine as indoxyl sulphate (50% of the dose), indoxyl glucuronide (11%), oxindole (1·4%), isatin (5·8%), 5-hydroxyoxindole conjugates (3·1%), N-formylanthranilic acid (0·5%) and unchanged indole (0·07%). The faeces contain indoxyl sulphate (0·4% of the dose) and indole (0·2%), but the major metabolites have not been identified. 4. Fed to rats with biliary cannulae an average of 5·6% of a dose of [¹⁴C]indole (20–60mg./kg. body wt.) is excreted in the bile in 2 days. Radioactivity is present as indoxyl sulphate (0·8% dose) and 5-hydroxyoxindole conjugates (0·6%). 5. Rats further metabolize indoxyl into N-formylanthranilic acid and anthranilic acid, and oxindole into 5-hydroxyoxindole. 6. With rat-liver microsomes plus supernatant under aerobic conditions, indole gives indoxyl, oxindole, possibly isatin, N-formylanthranilic acid and anthranilic acid, but under anaerobic conditions gives only oxindole. Similarly, under aerobic conditions, oxindole gives 5-hydroxyoxindole, anthranilic acid and o-aminophenylacetic acid. 7. Indole is metabolized by two pathways, one via indoxyl to isatin, N-formylanthranilic acid and anthranilic acid, and the other via oxindole to 5-hydroxyoxindole and possibly to o-aminophenylacetic and anthranilic acid. 8. The following new compounds are described: 4-hydroxy-2-nitrophenylacetic acid, 3-, 4- and 5-benzyloxy-2-nitrophenylacetic acid, 5- and 7-hydroxyoxindole and 5-aminoacridine indoxyl sulphate.     

Factors Controlling the Production of Lysogenic Cultures of B. megatherium

(1) The proportion of infected B. megatherium cells which develop lysogenic colonies depends on the number and kind of infecting virus particles and on the culture medium in which the cells are growing. (2) Cells infected with 100 or more T virus particles (from megatherium 899) in yeast extract peptone disintegrate, produce very few virus particles, and less than one lysogenic colony per 10⁷ infected cells. Cells infected with one or a few particles produce 500 to 1000 virus particles each and about 30 lysogenic colonies per 10⁷ infected colonies. (3) T phage obtained from lysogenic magatherium KM cultures produces many more lysogenic cells than does the original megatherium 899 virus. (4) Cells infected with megatherium 899 T virus in peptone medium and then transferred to asparagine medium give rise to 10⁶ lysogenic colonies per 10⁷ infected cells and this transformation will occur even after the infected cells have been in peptone for 60 to 90 minutes and are beginning to produce virus particles. (5) Continued growth of KM strain with either C or T virus from megatherium 899 for several hundred generations in the steady state apparatus results in a lysogenic strain which produces several different types of virus.