An Improved Agar Medium for the Detection of Proteolytic Organisms in Total Bacterial Counts

Abstract

PLATE 1 . Tdluencc of Calf on the precipitation of para-caseins. On each plate of SMCA, Micrococcus jreuclerweicl~ii is a t tho top with Serratia marcescens lower left, and Pseuclomonas fragi lower right. The medium contained: ( a ) no additional Caa+; (b) 0.015 m; 0.02 N. Incubation, 48 h/30'. YLATW 2. Zones duo t o protoolysis formed on ( a ) SMCA by Staphylococcus aureus (above), Sarcirto Zuten (lowcr left) andP6eudomonas fragi (lower right), and the effect of thew organisms on milk agar (0) before and (c) aftrr flooding with acidified HgCI, solution. Incubation, 60 h a t 30". Bact. f. 1). 3G4. YCATE 8. Prot,eolytic (P) and nonprotrolyt ir (N P ) roloriios clcarly diffrrontiatrrl o n a SMCA plats used to dotormine thc total and proteolytic count of raw milk. Incubation, 48 h a t 30".

Protein Degradation by Human Intestinal Bacteria

“…All manipulations were done in a Gallenkamp anaerobic cabinet containing a 10% Hz, 10% CO,, 80% N, atmosphere. The Wilkins-Chalgren plates had been preincubated for 48 h at 37 "C in the anaerobic cabinet before inoculation and, together with the yeast extract/lactate plates, were incubated in the anaerobic cabinet for up to 7 d. After inoculation, the azide agar and nutrient agar plates were removed from the anaerobic cabinet and incubated under aerobic conditions at 37 "C for up to 3 d. Proteolysis was detected either by zones of clearing around colonies, which were enhanced by addition of acid mercuric chloride solution, or alternatively by precipitation of casein around proteolytic colonies (Martley et al, 1970).…”

Extracellular proteolytic activity of Aeromonas hydrophila complex.

“…The responses of the fish, "other animal" and human groups to elastin were very close and significantly higher than that of the water group (Table 6). usually used to determine the proteolytic activity of bacterial organisms: 1) gelatin liquefaction based upon hydrolysis of gelatin in tubed medium (COWAN and STEEL, 1965); 2) an assay which detects either gelatin, casein , elastin or milk hy drolysis in a plate medium (FRAZIER , 1926;MARTLEY et al, 1970;SCHARMANN , 1972;SCHMMACHER and SCHILL, 1972;SMITH, 1946;SOKOL et al, 1979;VON RIESEN, 1975); 3) an enzymatic assay which detects the proteolytic ac tivity in a cultured broth using casein, azocasein or hemoglobin as a substrate (CHARNEY and TOMARELLI, 1974;DRAPEAU et al, 1972;REIMERDES and KLOSTERMEYER, 1976). The gelatin liquefac tion and plate assay are usually used for qualita tive studies.…”

Corynebacterium Acnes and Other Anaerobic Diphtheroids From Human Skin

“…Gelatin similarly was tested at 0.4% and precipitated with acid mercuric chloride. Casein hydrolysis was sought on standard-methods casein agar (SMCA) (Martley, Jayashankar and Lawrence, 1970) and recorded as " precipitate " or " clearing ". Indole and nitrate reductase were tested in the liquid Trypticase Nitrate Broth (BBL) by standard methods (Cowan and Steel, 1965).…”