Hi! I know that itís been a long time, but I have some interesting news about certain types of bacteria that you probably have encountered on your farms. I would like to take this opportunity to pass some helpful information to you. In this bulletin, I will be discissing thermoduric, thermophilic, and psychotropic bacteria, the effects on your milk production, and the treatment.

Thermoduric bacteria.
Thermoduric bacteria can survive exposure to temperatures considerably above their maximal temperature for growth. In the dairy industry, the term is applied to those organisms which survive, but do not grow, at pasteurization temperature. They usually include species of Micrococcus, Streptococcus, Lactobacillus, Bacillus, and occasionally gram-negative rods. The sources of contamination are poorly cleaned and sanitized utensils and equipment on farm and processing plants. These bacteria contribute to significantly higher Standard Plate Count on pasteurized milk (LPC counts). The thermoduric count has been used in the daity industry primarily as a test of care employed in utensil sanitation and as a means of detecting sources of organisms responsible for high counts in the final product.

Thermophilic bacteria.
In the dairy industry, the term thermophilic bacteria applies particularly to bacteria which grow in milk held at elevated temperatures (55 C or higher), including pasteurization, 62.8 C. The species that grow in higher temperatures include Bacillus species which enter milk from various sources in the farm, or from poorly cleaned equipment in the processing plant. When the milk is held at high temperatures for long periods, these bacteria rapidly increase in numbers and may cause flavors defects or problems with respect to bacteria standards. Counts of thermophilic bacteria are obtained by Standard Plate Count with plate incubation at 55 C. Numerous large, rod-shaped bacteria stain strongly and are the thermophilic bacteria.

Psychtropic bacteria.
The microorganisms which play a significant role in biological processes in low-temperature environments have usually been called psychrophilic, meaning cold-loving. Psychotropic is used to refer to the bacteria that are able to grow rapidly at 7 C and below. Species of Pseudomonas, Flavovacterium, Alcaligenes, Acinetobacter, and Bacillus are often encountered among psychotropic group. These group of are generally non-pathogens, but in dairy products they can cause a variety of off-flavors, including fruity, stale, bitter, putrid and rancid flavors. Psychotropic bacteria are rarely present in the udder. The numbers of bacteria depend upon sanitary conditions prevailing during production and upon time and temperature of milk storage before processing. The influence of psychotropic bacteria in the shelf life of pasteurized milk will depend mainly upon the number present after packaging, the rate of growth, the storage period, and the biochemical activity of the organisms.

The key concept for avoiding these organisms is sanitation!!!!

By keeping the equipment and processing plant properly sanitized, most of these organisms can be avoided. If you have any questions regarding this newsletter or would like more information on our tests for the thermoduric, thermophilic, and psychotropic bacteria plese call us at (909)947-6065. Until next time.