ISOLATION AND CHARACTERISTICS OF A YEAST FROM PRESERVED FISH HYDROLYSATE NOTABLY RESISTANT TO PROPIONIC-ACID

A fermentative him-forming yeast, designated PR1, notably resistant to propionic acid, was isolated from hydrolysed fish gurry that had been initially adjusted to a pH of 3.5 with phosphoric acid and preserved with 0.2% propionic acid. Growth on a variety of culture media yielded only budding cells. Bipolar budding with multiple buds at each pole w as commonly encountered. Neither ascospores nor pseudomycelium were pr oduced. Colonies on orange serum agar were 3-5 mm in diameter whereas, on tryptic soy agar containing 0.5% glucose, giant colonies were form ed that filled most of the area of the plates within 48 h. Off-odours were not produced nor were disaccharides utilized. The isolate exhibit ed poor growth in 0.4% propionic acid at pH 4.0 and was completely inh ibited by 0.5% propionic acid.