Nutrient agar

Abstract: A rapid procedure was devised for detecting on solid media bacteria able to degrade water-insoluble, solid hydrocarbons such as the polycyclic aromatic hydrocarbons phenanthrene, anthracene, and biphenyl After Alcaligenes faecalis AFK2 was inoculated on a plate containing mineral salts agar, an ethereal solution of phenanthrene (about 10%, wt/vol) was sprayed on the surface of the plate, and the plate was incubated at 30 degrees C for 2 to 3 days Colonies showing degradation were surrounded with clear zones on the opaque plate A similar clear zone also was formed around colonies which had been grown on a succinate-mineral salts agar or nutrient agar, followed by spraying of the ethereal solution of phenanthrene and further incubating for 1 day Other phenanthrene-assimilating bacteria, including Beijerinckia Bwt and Pseudomonas SPM64, also formed clear zones on phenanthrene-covered agar plates This method was applicable to detection of bacteria able to assimilate anthracene, naphthalene, and biphenyl

Abstract: Seventy-four of 110 strains of Pseudomonas aeruginosa tested produced detectable amounts of HCN from growth in 2% peptone or nutrient agar. Of the 25 species of 12 bacterial and fungal genera teste...

Abstract: 1. The inclusion of formic and propionic acids in the form of Bio-Add to the food of hens made no difference to the pH of the intestinal tract, but resulted in higher concentrations of these acids in the contents of the crop and gizzard. 2. Organic acids in the crop contents were bactericidal for Salmonella serotype Enteritidis PT4 in vitro, and also caused sub-lethal damage because fewer cells were recovered on selective salmonella media (brilliant green phenol red agar) than on non-selective media (nutrient agar). 3. Inclusion of Bio-Add in the food at 12g/kg may reduce the number of lactic acid-producing bacteria in the crop, and hence the amount of naturally produced organic acids.

Abstract: Vineyard, winery, barrel, and controlled temperature fermentation samples from a single commercial winery (Luna Vineyards) conducting fermentations with indigenous organisms were plated onto Wallerstein Laboratory Nutrient Agar (WL) to evaluate colony diversity. Seventeen unique colony morphologies were identified. Sequence analysis of the DNA encoding a portion of the large ribosomal 26S rRNA indicated that the colony types defined members of six genera: Hanseniaspora uvarum (Kloeckera apiculata), Saccharomyces cerevisiae, Issatchenkia orientalis, Pichia kluyveri, Candida olephelia, and Metschnikowia. Distinct colony subtypes were identified within the pulcherrimin producers traditionally classified as a single species, Metschnikowia pulcherrima. Sequence analysis of the D1/D2 region of the 26S rDNA of these biotypes showed a high degree of divergence, suggesting that these organisms might define separate species. Analysis of fermentations revealed that colony type as indicated on this medium could be used to monitor the yeast population dynamics.