SUMMARY: Glucose utilization by a strain of Streptomyces griseus was studied. Under highly aerobic conditions, glucose was converted mainly to structural material and CO,, but under restricted aeration, lactic acid was formed. Pyruvic acid was also formed during the stages of most rapid growth. The metabolism of glucose was dependent upon the presence of phosphate, and the optimal hydrogenion concentration for both glucose oxidation and the rate of disappearance of inorganic phosphate was about pH 7. Phosphate esters, tentatively identified as glucose-1-phosphate and glucose-6-phosphate, were obtained in fluoride-inhibited systems. Glucose oxidation was depressed by M-sodium iodoacetate and Msodium arsenite but was stimulated by 10-2M-sodium arsenate ; 1 0 -3~-2 : 4-dinitrophenol and 10-sM-sodium azide had no effect. Streptomycin production was decreased by 3 x lO-*M-sodium arsenate but not by 10-2M-sodium fluoride or ~O-*Msodium iodoacetate. S. griseus metabolized members of the tricarboxylic acid cycle, although citrate and a-ketoglutarate gave much lower values of Qo, a t pH 7.3 than pyruvate, acetate, succinate, fumarate or malate. Ketoacids were produced in presence of arsenite from fumarate, malate, glucose, lactate, acetate, succinate, glutamate and citrate in descending order of yield. Except from fumarate, which yielded some material behaving like a-ketoglutarate, the product was chiefly p p v a t e .

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.

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