a nitrogen-containing polysaccharide. Re- ciprocal cross-reactions occur between this group and type I Streptococcus salivarius, thus indicating a similarity in their capsular antigens. Capsular swelling can be demon- strated in the presence of homologous im- mune serum. Rough variants lacking the capsular antigen can be induced by cultur- ing in the presence of homologous immune sera. Action on blood: Greening (alpha hemo- lytic) or indifferent (gamma hemolj'tic). The reaction is variable depending upon the type of blood employed. No soluble hemolysin is produced. Temperature relations: No growth at 10° or at 45° C. Does not survive 56° C. for 30 minutes. Tolerance tests : No growth in broth con- taining 6.5 per cent NaCl. No growth at pH 9.6. Growth in milk containing 0.005 per cent methylene blue but not in 0.02 per cent methylene blue. Growth on 10 per cent bile blood agar. Maj^ or may not grow on 40 per cent bile blood agar. Litmus milk: Acidified and curdled with reduction of litmus after curdling. No di- gestion. Final pH in glucose broth, between 4.3 and 5.6. Produces small colonies on 5 per cent sucrose agar that are fluorescent under ultraviolet light. Acid from glucose, maltose, lactose, sucrose and salicin. May or may not fer- ment trehalose. No acid from xylose, arabinose, raffinose, inulin, glycerol, man- nitol or sorbitol. Starch, sodium hippurate and gelatin not hydrolyzed. Esculin split. Ammonia produced from arginine. Comments: This group of streptococci is of particular interest because of its associa- tion with primary atypical pneumonia. Pa- tients recuperating from this disease develop precipitins and agglutinins in their blood against this streptococcus, as well as against Streptococcus salivarius type I. In contrast with other viridans strepto- cocci, this group appears to be particularly resistant to the sulfonamides. Source : Saliva, sputum and lung cultures from cases of primary atypical pneumonia. Also found in the respiratory tract of nor- mal individuals. Genus III. Pediococcus Balcke, 1884f emend. Mees, 1934.* (Balcke, Wochnschr. f. Brauerei, 1 , 1884, 257; Mees, Onderzoekingen over de Biersarcina. Thesis, Delft, 1934, 92.) Pe.di.o.coc'cus. Gr. noun pedium a plane; Gr. noun coccus a berry, sphere; M.L. mas.n. Pediococcus plane coccus. Cocci occurring singly, as tetrads, pairs or even short chains. Although these organisms are frequently called sarcinae in the literature, packets of eight cells, if they occur at all, are very rare. Non-motile. Gram-positive. Microaerophilic, showing poor surface growth. Generally catalase-negative in sugar media. Homofermentative, producing optically inac- tive lactic acid from carbohydrates. Nitrites not produced from nitrates. Produce acidifica- tion and more or less clouding of wort and beer. Saprophytes in fermenting vegetable juices. The type species is Pediococcus cerevisiae Balcke. Keij to the species of genus Pediococcus. I. Optimum temperature, between 25° and 32°C. Grows in wort, hopped wort and beer. 1. Pediococcus cerevisiae. II. Optimum temperatxire, about 40°C. Grows in unhopped wort but not in beer. 2. Pediococcus acidilactici .
- Prepared by Prof. Carl S. Pederson, New York State Experiment Station, Geneva, New
York, September, 1954.
