Casein utilization by Streptococcus thermophilus results in a diauxic growth in milk.
نویسندگان
چکیده
In milk, Streptococcus thermophilus displays two distinct exponential growth phases, separated by a nonexponential one, during which proteinase synthesis was initiated. During the second exponential phase, utilization of caseins as the source of amino acids resulted in a decrease in growth rate, presumably caused by a limiting peptide transport activity.
منابع مشابه
The Effect of Milk Supplementation on the Growth and Viability of Starter and Probiotic Bacteria in Yogurt during Refrigerated Storage
In the present work, the effect of milk supplementation on viability of yogurt bacteria (Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus) and probiotic bacteria (Lactobacillus acidophilus and Bifidobacteria) was studied during yogurt manufacture and thirty three days storage. Incubation time to reach pH value of 4.5 was greatly affected by the addition of casein fract...
متن کاملCell-wall proteinases PrtS and PrtB have a different role in Streptococcus thermophilus/Lactobacillus bulgaricus mixed cultures in milk.
The manufacture of yoghurt relies on the simultaneous utilization of two starters: Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus (Lb. bulgaricus). A protocooperation usually takes place between the two species, which often results in enhanced milk acidification and aroma formation compared to pure cultures. Cell-wall proteinases of Lactococcus lactis and lactobacill...
متن کاملEffect of Cysteine and Lysine on Some Technical Properties of Yoghurt Starter Culture Bacteria
Background and Objectives: Enhancing the growth and function of lactic acid bacteria through fortifying the basic ingredient of yogurt, milk ,have always been a key factor in the application as an industrial starter culture. The purpose of the present study is to introduce the application of certain materials in yoghurt milk with the aim of enhancing the growth and acid production, and reductio...
متن کاملCharacterization of a Cell Envelope-Associated Proteinase Activity from Streptococcus thermophilus H-Strains.
The production and biochemical properties of cell envelope-associated proteinases from two strains of Streptococcus thermophilus (strains CNRZ 385 and CNRZ 703) were compared. No significant difference in proteinase activity was found for strain CNRZ 385 when cells were grown in skim milk medium and M17 broth. Strain CNRZ 703 exhibited a threefold-higher proteinase activity when cells were grow...
متن کاملThe global regulator CodY in Streptococcus thermophilus controls the metabolic network for escalating growth in the milk environment.
CodY is a transcriptional regulator conserved in the low-GC group of Gram-positive bacteria. In this work, we demonstrated the presence in Streptococcus thermophilus ST2017 of a functional member of the CodY family of global regulatory proteins, S. thermophilus CodY (CodYSt). The CodYSt regulon was identified by transcriptome analysis; it consisted predominantly of genes involved in amino acid ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Applied and environmental microbiology
دوره 68 6 شماره
صفحات -
تاریخ انتشار 2002