Guanosine tetraphosphate (ppGpp) is a key mediator of stringent control, an adaptive response of bacteria to amino acid starvation, and has thus been termed a bacterial alarmone. Previous X-ray crystallographic analysis has provided a structural basis for the transcriptional regulation of RNA polymerase activity by ppGpp in the thermophilic bacterium Thermus thermophilus. Here we investigated t...

The host-vector system for an extreme thermophile, Thermus thermophilus HB27, was developed. The host strain has a mutation in tryptophan synthetase gene (trpB), and the mutation was determined to be a missense mutation by DNA sequence analysis. A Thermus-E. coli shuttle vector pYK109 was constructed. pYK109 consists of Thermus cryptic plasmid pTT8, tryptophan synthetase gene (trpB) of Thermus ...

A cytochrome c (NarC) is encoded as the first gene of the operon for nitrate respiration in Thermus thermophilus. NarC is required for anaerobic growth and for the synthesis of active nitrate reductase (NR). The alpha and delta subunits (NarG, NarJ) of the NR were constitutively expressed in narC::kat mutants, but NarG appeared in the soluble fraction instead of associated with the membranes. O...

Thermus thermophilus MutS, a thermostable mismatch-recognizing protein, is utilized in PCR to suppress nonspecific amplification by preventing synthesis from mismatched primers. T. thermophilus RecA also decreases nonspecific amplification by promoting proper hybridization between the primer and template. We observed that MutS and RecA function under the same reaction conditions and that MutS a...

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...

Of the nine media tested, Eugon, Elliker's lactic agar, pH 6.8, and modified tryptic soy broth agars showed superior recovery of Lactobacillus bulgaricus and Streptococcus thermophilus strains.

Probiotics can ferment nondigestible carbohydrates and produce short-chain fatty acids (SCFA; acetate, propionate, butyrate) in the human colon. In this study, levels of SCFA were determined following yogurts fermented with different combinations probiotics: (1) cocultures Streptococcus thermophilus Lactobacillus bulgaricus (control, C); (2) S. thermophilus, L. bulgaricus, Bifidobacterium bifid...

Streptococcus thermophilus is widely used as a starter culture in the fermentation of yogurt. Glutathione (GSH; γ-glutamyl-cysteinyl-glycine), tripeptide, has an important physiological role for Strep. thermophilus. However, scope GSH transport proteins still unexplored this species. In present study, 5 peptide transporter-related (Ptrp) strain ST-1 were selected and then inactivated by gene in...