Antimicrobial and anti-lipase activity of quercetin and its C2-C16 3-O-acyl-esters.

A total of 123 isolates of 14 species of dermatophytes and yeasts were screened for the activity of five extracellular enzymes including elastase, keratinase, protease (gelatinase), lipase and phospholipase, by using solid media. The optimal production and activity of each enzyme was determined with regard to different pH and temperatures. Keratinase activity was high with all the tested fungi with exception of Malassezia furfur. Protease (gelatinase) was produced only by dermatophytes. Elastase was secreted by three dermatophytes viz. Microsporum gypseum, Trichophyton mentagrophytes var. mentagrophytes and T. verrucosum, whereas lipase and phospholipase were detected in all the species except T. violaceum.

Extracellular enzyme activities of dermatophytes and yeast isolates on solid media

Physiology of keratinophilic fungi.

An exocellular proteinase produced by Trichophyton rubrum in a glucose-peptone broth was purified from lyophilized and dialysed culture filtrate of the dermatophyte by Sephadex G-100 gel filtration and preparative polyacrylamide gel electrophoresis. The purified enzyme was a homogeneous protein of molecular weight 34 700 and it could hydrolyse azoalbumin, casein, bovine serum albumin, α-N-benzoyl-L-arginine ethyl ester and p-toluenesulfonyl-L-arginine methyl ester but not N-benzoyl-L-tyrosine ethyl ester, α-N-benzoyl-DL-arginine-p-nitroanilide and keratin. The enzyme showed an alkaline pH optimum and was not activated by divalent metal ions but inhibited strongly by phenylmethylsulfonylfluoride. Thus the enzyme was identified as an alkaline serine proteinase.

Purification and partial characterization of an exocellular proteinase from Trichophyton rubrum

Barrier Function, Epidermal Differentiation, and Human β-Defensin 2 Expression in Tinea Corporis

Trichophyton rubrum cells contain lipase, phospholipases A and B and acyl CoA lysolecithin acyl transferase activities. This dermatophyte excretes lipase and phospholipase A into the growth medium when cultivated in Sabouraud's broth. Extracellular lipase has optimum activity at pH 8.0 whereas the intracellular lipase is maximally active at pH 8.0 whereas the intracellular lipase is maximally active at pH 7.0. The optimum pH of phospholipase A and B activities which are localized in 15000 g sedimentable cell fragments are 7.0 and 6.0 respectively. Supernatant obtained after removal of 1,005,000 g sedimentable fragments from cell extract contains acyl CoA lysolecithin acyl transferase which requires ATP, CoA, Mg2+ and an unsaturated fatty acid for its activity.

Lipolytic enzymes of Trichophyton rubrum

Trichophyton rubrum grown in Sabouraud's liquid medium contains phosphatidyl inositol, polyphosphatidyl inositol, phosphatidyl choline, phosphatidyl serine, phosphatidyl ethanolamine phosphatidyl glycerol and phosphatidic acid in the polar lipid fraction of its mycelia. The relative proportion of these components in total phospholipid fraction remains almost constant throughout the culture life of this fungus.

Phospholipids of Trichophyton rubrum.

Phospholipid synthesis, interconversion and breakdown in T. rubrum were followed by radioactive tracer. Synthesis and catabolism of phosphatidyl ethanolamine and phosphatidyl serine are most rapid; phosphatidyl choline and phosphatidyl inositol are metabolised rather slowly. Catabolism of phosphatidyl ethanolamine and phosphatidyl serine are uniform and their conversions to phosphatidyl choline and phosphatidyl inositol are suspected.

A.B. Banerjee

Papers

Lipolytic enzymes of Trichophyton rubrum

Phospholipids of Trichophyton rubrum.

Phospholipid turnover in Trichophyton rubrum