Actinomycete metabolism: origin of the guanidine groups in streptomycin

Abstract

32p INTO LIPIDS AND PNA OF DEGENERATING NERVE 249 3. In nerves degenerating after section and incubated under the same conditions, there was a large increase in the specific activity of the lipid P. During the early stages of the degeneration (8 and 16 days after nerve section) there was a decrease in the specific activity of the PNA and ROP. At 8, 16 and 32 days after nerve section the activity of the lipid P and PNA/100 mg. nerve was greater than the corresponding figure for control nerves. 4. In regenerating nerves 32 days after nerve crush, the specific activity of each of the four Pcontaining fractions did not differ significantly from that of the corresponding fraction 32 days after nerve section. By 96 days after the operation the specific activity of the lipid P was significantly less than that of the lipid P of nerves at the same time interval after section. The activity/100 mg. nerve was considerably greater.

Studies on the Biosynthesis of Streptomycin

“…This was not expected a priori, because the bulk of the antibiotic was produced only after 48 hr. The results, however, are in agreement with the observation of Hunter et al (1954), who concluded from experiments concerned with the rate of the incorporation of labeled compounds that some precursors are elaborated sometime before streptomycin actually appears.…”

“…TABLE 1. Composition of three synthetic media utsed in this study Ingredients Temple Lumb (1949) Carvajal (1948) degradation to streptidine and streptobiosamine were carried out by the method of Hunter et al (1954). All radioactivity measurements were made with a G.MI.…”

Actinomycete metabolism. Incorporation of 14C-labelled compounds into streptomycin

“…The organism, Streptomyces grisews, albus mutant (Dulaney Z. 38), was grown on a soybean medium as described previously (Hockenhull, Fantes, Herbert & Whitehead, 1954;Hunter et al 1954). Unless otherwise stated, cultures were harvested 7 days after inoculation.…”

“…The radioactive labels of added [14C]glycine and acetate were significantly incorporated only in the guanidine side chains. As these carbon atoms arise largely, if not entirely, from carbon dioxide (Hunter, Herbert & Hockenhull, 1954), atoms from the substrate are presumably incorporated only after these have been completely metabolized by the organism. Karow, Peck, Rosenblum & Woodbury (1952) have demonstrated the incorporation of the labelled carbon of [14C]glucose into streptomycin.…”

Variations in Strains of Streptomyces griseus Isolated from a Degenerating Streptomycin-Producing Culture

“…If it were true, then streptidine should have a stimulatory effect on streptomycin production. Streptidine sulfate was prepared from dihydrostreptomycin sulfate by the method of Hunter, Herbert, and Hockenhull (1954), and used to supplement the basal medium (Table 5). Streptidine had a distinct stimulatory effect on all groups employed, although the total production by the low potency group was still low.…”