Molecular identification and probiotic properties of ‘lactobacillus acidophilus group’ isolates from Turkish kefir/

Download

index.pdf

Date

2014

Author

Gülel, Şebnem

Metadata

Show full item record

Item Usage Stats

192
views

127
downloads

Lactic acid bacteria (LAB) are Gram-positive, non-spore-forming, rods, cocci or coccobacilli that ferment glucose primarily to lactic acid, or lactic acid, carbon dioxide and ethanol. These bacteria are among the most important group of microorganisms used in food and beverage fermentations. Lactobacillus species comprise the major part of LAB and a number of them are used as probiotic strains in order to benefit human health. In this study, four ‘Lactobacillus acidophilus group’ isolates from Turkish kefir were identified by using molecular identification techniques and also investigated for their probiotic characteristics. Their molecular identification was done by sequence comparison of PCR (polymerase chain reaction) amplified V1 region of the 16S rRNA gene, isolated from the strains, with sequences of Lactobacillus acidophilus group type strains. The comparison identified all four kefir isolates of Lactobacillus acidophilus group as Lactobacillus amylovorus. The identified strains were further investigated for their probiotic properties, including acid tolerance, bile salt tolerance and cell surface hydrophobicity. A commercial probiotic strain, LA05, was also investigated in order to use its data as a reference for kefir isolates. All of these strains were also tested for antibiotic susceptibility to determine the existing antibiotic resistant genes that might be involve in horizontal gene transfer. Antibiotics belonging to the groups of inhibitors of cell wall synthesis, inhibitors of protein synthesis, inhibitors of nucleic acid synthesis and inhibitors of cytoplasmic membrane were used. All kefir isolates showed high tolerance against both acid and bile salts, but exhibited low hydrophobicity. They showed high resistance to nucleic acid synthesis inhibitors and cytoplasmic membrane inhibitors, but low resistance to the inhibitors of cell wall synthesis and to the majority of protein synthesis inhibitors. The results were the same for the commercial probiotic, the strain LA05. Since in vitro analyses do not necessarily correlate in vivo analyses, these results are sufficient to consider these ‘Lactobacillus acidophilus group’ isolates from Turkish kefir as promising candidates for use as commercial probiotic strains.

Subject Keywords

Probiotics., Kefir., Lactobacillus acidophilus., Molecular biotechnology.

URI

http://etd.lib.metu.edu.tr/upload/12617589/index.pdf
https://hdl.handle.net/11511/23693

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Purification of microbially produced ca-l(+)-lactate with a novel technique: drying induced elution of impurities Özçelik, Damla; Hamamcı, Haluk; Department of Food Engineering (2016) For the production of calcium L-(+)-lactate (Ca-L(+)-Lactate) fermentation was performed by using Lactobacillus casei. Production with inexpensive raw materials and low cost purification of lactic acid (LA) as Ca-L(+)-Lactate was aimed because LA production from renewable materials is limited due to high production and purification costs. Fermentation conditions were 37°C for temperature, pH was kept at 5.5 by adding CaCO3 as neutralizer and stirring was adjusted at 120 rpm. Fermentation medium consisted of...
Investigation of sugar metabolism in rhizopus oryzae Büyükkileci, Ali Oğuz; Hamamcı, Haluk; Department of Biotechnology (2007) Rhizopus oryzae is a filamentous fungus, which can produce high amounts of L(+)-lactic acid and produces ethanol as the main by-product. In an effort to understand the pyruvate branch point of this organism, fermentations under different inoculum and glucose concentrations were carried out. At low inoculum size (1x103 spores ml-1), high amount of lactate (78 g l-1) was produced, whereas high ethanol concentration (37 g l-1) was obtained at high inoculum sizes (1x106 spores ml-1). Decreasing working volume i...
Biochemical and genetic studies on the pyruvate branch point enzymes of rhizopus oryzae Açar, Şeyda; Hamamcı, Haluk; Department of Biotechnology (2004) Rhizopus oryzae is a filamentous fungi which produces lactic acid and ethanol in fermentations. R. oryzae has numerous advantages for use industrial production of L-(+)-lactic acid but the yield of lactic acid produced on the basis of carbon consumed is low. Metabolic flux analysis of R. oryzae has shown that most of the pyruvate produced at the end of the glycolysis is channelled to ethanol, acetyl-CoA and oxaloacetate production. This study aimed to answer some questions addressed on the regulation of pyr...
Studies on novel immunogenic proteins of Clostridium Chauvoei Coral, Didem; Özcengiz, Gülay; Department of Biotechnology (2009) Clostridium chauvoei is a gram-positive, spore-forming anaerobic bacterium. It is the pathogenic agent of blackleg, a disease causing serious toxemia and high mortality in cattle, sheep and many other domestic and wild animals. It is considered the most important Clostridium producing economic losses in livestock. Typically, animals infected with blackleg die rapidly without any signs of illness. Animals quickly die within 12 to 48 hours after contracting the disease. Therefore, the control of this disease ...
Emerging cellular functions of the lipid metabolizing enzyme 15-Lipoxygenase-1 Colakoglu, Melis; Tuncer, Sinem; Banerjee, Sreeparna (Wiley, 2018-10-01) The oxygenation of polyunsaturated fatty acids such as arachidonic and linoleic acid through lipoxygenases (LOXs) and cyclooxygenases (COXs) leads to the production of bioactive lipids that are important both in the induction of acute inflammation and its resolution. Amongst the several isoforms of LOX that are expressed in mammals, 15-LOX-1 was shown to be important both in the context of inflammation, being expressed in cells of the immune system, and in epithelial cells where the enzyme has been shown to...

Citation Formats

Ş. Gülel, “Molecular identification and probiotic properties of ‘lactobacillus acidophilus group’ isolates from Turkish kefir/,” M.S. - Master of Science, Middle East Technical University, 2014.