Cryophilic Organisms in Water and Butter

The Effect of Cold on Micro‐organisms in Relation to Dairying

“…It has been reported from America, however, that 6 out of 41 psychrophiles isolated from dairy products survived 30 min. at 66" (Jezeski & Macy, 1946), a result which differs from the findings of other workers, even in America (Sherman, Stark & Gunsalus, 1938;Sherman, Cameron & White, 1941). In this country it was observed about 1935 that some psychrophiles, including spore-formers, could survive pasteurization (Ashton, 1951) and quite recently Canadian workers have reported that 4 out of 733 strains of psychrophilic organisms isolated from milk and cream were capable of surviving laboratory pasteurization.…”

Some Observations on the Bacterial Flora of Farm Water Supplies

“…The incidence of the types of organisms producing colonies at 3-5" C. agreed very closely with that obtained by Taylor (1942) a t 20" C. In this connexion Thomas and Chandra Sekhar (1946) found that psychrophilic cultures isolated from milk produced well developed colonies on yeastrel milk agar in 2 days at 22" C. and were more active biochemically at this temperature. Jezeski and Macy (1946) studied 41 cultures of psychrophilic organisms (7 days at 8" C.) isolated from creamery water supplies and butter samples. All were Gram-negative rods and 28 were classified as Pseudomonas, 5 as Flavobacterium, 6 as Alcaligenes, 1 as Achromobacter and 1 was a non-lactose-fermenting yeast.…”

LIPOLYTIC ACTIVITY OF MICROORGANISMS AT LOW AND INTERMEDIATE TEMPERATURES. I. ACTION OF PSEUDOMONAS FLUORESCENS ON LARDa

“…The importance of lipolytic activity of microorganisms in meats, meat products, and dairy products held at low temperatures has been recognized for many years (5,6,7,9). Although there have been numerous investigations on various factors affecting the production of lipase by microorganisms, only a few have been concerned with the effects of temperature, Nashif and Nelson (10) found that Pseudomonas frag; had an optimum temperature around 15" C for lipase production and that several other Gram-negative bacteria produced maximum quantities of lipase around 20" C even though the optimum temperature for activity of the lipases was near 40" C (12).…”