Lipolytic Activity of Human Cutaneous Bacteria

Abstract

SUMMARY: Forty-two strains of Corynebacterium acnes were compared with 20 strains of staphylococci and 10 of lipophilic diphtheroids for their lipolytic action on 14 substrates and for Tween 80 hydrolysis. All strains were isolated from normal human skin. One lipophilic diphtheroid and 33 C. acnes strains hydrolysed tributyrin. Forty-nine bacillary strains hydrolysed Tween 80. None of the other substrates was degraded. C. xerosis atcc 373 and Propioni-bacterium acnes atcc 11828 acted on tributyrin. P. acnes also hydrolysed Tween 80. The staphylococci did not act on Tween 80 but attacked tributyrin, triolein, trilinolenin, trilinolein and oil emulsions. Some cocci acted on tricaprylin, tricaprin and trilaurin; no lipolysis by this group was observed of trimyristin, tripalmitin or tristearin. Pancreatic lipase, tested by the penicylinder diffusion method for comparison, was active on the same substrates, as were the cocci. The addition of glucose, lactate and urea to media did not inhibit lipolysis by the cocci. Sodium oleate inhibited pancreatic lipase action on triolein and cottonseed oil but not on the hydrolysis of tributyrin. Coccal lipase action was not inhibited by oleate. All 74 test strains were uniformly inhibited by neomycin 5–10 μg./ml. Gram-positive cocci rather than C. acnes appear primarily responsible for bacterial lipase activity on human skin.