title: Prevalence of thermoduric bacteria and spores in nonfat dry milk powders of Midwest origin.
abstract: Samples of nonfat dry milk powder were analyzed for the presence of heat-resistant bacteria. The samples were collected from Midwest manufacturing companies and were evaluated for the presence of spores, thermoduric bacteria, and the total bacterial count. Three companies were included in this study, and results showed differences between each of the companies in the heat-resistant microbial groups tested. Company 3 had the highest levels of total spores and thermoduric bacteria: 3.6±0.14 and 3.5±0.13 log cfu/g, respectively. Interestingly, this company did not have the highest total bacterial count but rather the second lowest total bacterial count for the group, perhaps because of the higher proportion of thermophiles present in the powders from this company. The average level of total bacterial counts was 2.57±0.07 log cfu/g. Isolates obtained from the samples were identified by mass spectrometry, and all of the companies showed Bacillus licheniformis as the most prevalent bacterial species identified.
authors.affiliation: Midwest Dairy Foods Research Center, Dairy Science Department, South Dakota State University, Brookings 57007.
authors.forename: Kimberly P
authors.initials: KP
authors.lastname: Buehner
authors.affiliation: Midwest Dairy Foods Research Center, Dairy Science Department, South Dakota State University, Brookings 57007. Electronic address: Sanjeev.anand@sdstate.edu.
authors.forename: Sanjeev
authors.initials: S
authors.lastname: Anand
authors.affiliation: Department of Mathematics and Statistics, South Dakota State University, Brookings 57007.
authors.forename: Gemechis D
authors.initials: GD
authors.lastname: Djira
mesh_terms: D000818:Animals; D001407:Bacillus / Q000302:isolation & purification; D001419:Bacteria / Q000302:isolation & purification*; D058491:Bacterial Load; D015146:Midwestern United States; D008892:Milk / Q000382:microbiology*; D011208:Powders
chemical_list: D011208:Powders
keywords: Bacillus; highly heat-resistant spores; spore; thermoduric bacteria