JDS
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Journal of Dairy Science Vol. 51 No. 10 1579-1582
© 1968 by American Dairy Science Association ®
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Mikolajcik, E. M.
Right arrow Articles by Koka, M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Mikolajcik, E. M.
Right arrow Articles by Koka, M.

Bacilli in Milk. I. Spore Germination and Growth1

E. M. Mikolajcik and M. Koka2

Department of Dairy Technology, The Ohio State University, Columbus

ABSTRACT

The influence of the heat treatment of the spore and of the milk upon germination, outgrowth, and subsequent vegetative cell growth of Bacillus cereus 7 spores was determined in raw (unheated), pasteurized (62.8 C-30 min), high-heated (100 C-10 min), autoclaved (121 C-10 min) skimmilks. Pollowing 2 hr incubation at 35 C, the per cent germination for the unheated spores was 27.3, 89.7, 65.2, and 15.6, and for the heat-shocked (80 C-12 min) spores it was 67.8, 99.5, 94.9, and 83.5 in raw, pasteurized, high-heated, and autoclaved skimmilks, respectively. The time required for the spores to germinate, outgrow, and initiate active cell multiplication ranged from 124 min for the heat-shocked spores in pasteurized milk to 355 min for the unheated spores in raw milk. When vegetative cells in exponential growth were inoculated into the various milk systems, the rate of growth for the first 30 min in raw milk was approximately one-half that for pasteurized or high-heated milk. However, upon continued incubation no differences in generation time or number of generations were noted between the raw and heated milks. Heat treatment of the spore stimulated germination and subsequent outgrowth; whereas, heat treatment of the milk affected the initial rate of active cell multiplication.

FOOTNOTES

1 Article 2:68. Department of Dairy Technology, The Ohio State University. This investigation was supported by Public Health Services Grant UI-00106 from the National Center for Urban and Industrial Health.

2 Present address: Argonne Cancer Research Hospital, Chicago, Illinois 60637.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1968 by the American Dairy Science Association ®.