Molecular methods for identification of Lactobacillus delbrueckii subsp bulgaricus and Streptococcus thermophilus using methionine biosynthesis and 16S rRNA genes

Date

2008-11-01

Author

Cebeci, Aysun
Gültekin, Güzin Candan

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

169
views

0
downloads

Yoghurt and starter culture producers are still searching strains of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus to produce healthier yogurt with longer shelf life, better texture, taste and quality. However, selective identification of Lb. delbrueckii subsp. bulgaricus and Strep. thermophilus from a mixed population using microbiological and biochemical methods is difficult, time consuming and may not be accurate. In this study, a quick, sensitive and accurate method is proposed to identify both Lb. delbrueckii subsp. bulgaricus and Strep. thermophilus using PCR. The method is comprised of two parts. In the first part, methionine biosynthesis genes, known to be present in both species were partially amplified by designed primers (cysmet2F and cysmet2R). Partial amplification of the methionine biosynthesis gene which gives 700 bp fragment resulted in selective identification of Lb. bulgaricus and Strep. thermophilus. All 16 Lb. bulgaricus and 6 Strep. thermophilus isolates assessed by this method gave the expected amplification. On the other hand, further analysis of other closely related species with the same primers have indicated that the same product was also amplified in two more lactobacilli namely, Lb. delbrueckii subsp. lactis and Lb. helveticus species. Thus, in the second part of the method, further differentiation of Lb. delbrueckii subsp. bulgaricus and Strep. thermophilus from each other and these species was achieved using restriction analysis of 16S rRNA gene with EcoRl.

Subject Keywords

Food Science, Animal Science and Zoology, General Medicine

URI

https://hdl.handle.net/11511/47444

Journal

JOURNAL OF DAIRY RESEARCH

DOI

https://doi.org/10.1017/s0022029908003543

Collections

Department of Food Engineering, Article

Suggestions

OpenMETU
Core

Identification and killer activity of a yeast contaminating starter cultures of Saccharomyces cerevisiae strains used in the Turkish baking industry Izgu, F; Altinbay, D; Yucelis, A (Elsevier BV, 1997-04-01) The yeast contaminating the starter cultures of Saccharomyces cerevisiae fermentation strains BSP 1-4, used in the Turkish baking industry, was identified as Candida tropicalis with a killer phenotype. The activity of the killer toxin against the industrial strains was optimum at pH 3.9 and 4.1 at 22-25 degrees C. The activities of some killer toxin-producing yeasts of known phenotypes against C. tropicalis were determined. Among the yeasts tested S. cerevisiae K3 and Hansenula anamola K8 were inhibitory to...
Immunization of the industrial fermentation starter culture strain of Saccharomyces cerevisiae to a contaminating killer toxin-producing Candida tropicalis Izgu, F; Altinbay, D; Derinel, Y (Elsevier BV, 2004-12-01) K3 killer trait was introduced into the fermentation starter strain of Saccharomyces cerevisiae BSP 1 in order to construct immune industrial strain that produces K3 type killer toxin and was resistant to Candida tropicalis (K+) contamination. Protoplasts of respiration-deficient Rhodegrees strain of S. cerevisiae NCYC 761 (K3) and S. cerevisiae BSP 1 were fused. The resulting respiration-competent hybrid with K3 type killer activity was selected on media containing a non-fermentable carbon source and by a ...
Cloning of the scytalidium thermophilum bifunctional catalase / phenol oxidase gene and expression in aspergillus sojae Erçin, Hatice Özlem; Ögel, Zümrüt Begüm; Department of Food Engineering (2008) Scytalidium thermophilum is a thermophilic fungus with an important role in the composting process of mushroom cultivation. An extracellular phenol oxidase of Scytalidium thermophilum (STEP) with novel features was previously studied in our laboratory. This enzyme later turned out to be a catalase having phenol oxidase activity. The aim of this study was to clone Scytalidium thermophilum bifunctional catalase/phenol oxidase encoding gene and express the gene in Aspergillus sojae for future site directed mut...
Differentiation of Anatolian honey samples from different botanical origins by ATR-FTIR spectroscopy using multivariate analysis Gok, Seher; Severcan, Mete; Goormaghtigh, Erik; KANDEMİR, İRFAN; Severcan, Feride (Elsevier BV, 2015-03-01) Botanical origin of the nectar predominantly affects the chemical composition of honey. Analytical techniques used for reliable honey authentication are mostly time consuming and expensive. Additionally, they cannot provide 100% efficiency in accurate authentication. Therefore, alternatives for the determination of floral origin of honey need to be developed. This study aims to discriminate characteristic Anatolian honey samples from different botanical origins based on the differences in their molecular co...
Monitoring the effects of divalent ions (Mn+2 and Ca+2) in heat-set whey protein gels Öztop, Halil Mecit; MCCARTHY, Michael J.; ROSENBERG, Moshe (Elsevier BV, 2014-04-01) Exploring the effects of cations in whey protein-based gels (WPG) is of importance when these gels are used for controlled release applications in food systems. The objective of this study was to evaluate both water uptake and cation release from heat-set WPGs. Magnetic Resonance Imaging and NMR relaxometry were employed to study the uptake and release. A non-paramagnetic (Ca+2) and a paramagnetic cation (Mn+2) were incorporated into the WPG as model divalent cations. Cylindrical pieces of WPGs with mangane...

Citation Formats

A. Cebeci and G. C. Gültekin, “Molecular methods for identification of Lactobacillus delbrueckii subsp bulgaricus and Streptococcus thermophilus using methionine biosynthesis and 16S rRNA genes,” JOURNAL OF DAIRY RESEARCH, pp. 392–398, 2008, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/47444.