Detection of probiotic microorganisms using RT-PCR, and isolation, identification, probiotic properties of lactobacillus species from kefir

Download

12625908.pdf

Date

2020-10-26

Author

Hassan, Manal Sami El Sayed

Metadata

Show full item record

Item Usage Stats

695
views

662
downloads

Kefir is a dairy product rich in probiotics. In this study, a SYBR green-based realtime PCR (RT PCR) method was used for the detection of kefir probiotic strains. This assay allowed species-specific detection of L. acidophilus, L. delbrueckii subsp.bulgaricus, L. kefiri, L. kefiranofaciens, L. fermentum, L. plantarum, L. amylovorus, L. casei, L. paracasei, Streptococcus thermophilus and Saccharomyces cerevisiae. This method was performed using DNA isolated directly from five different sources of kefir from Turkey and one milk product from Kyrgyzstan. Results of amplification and melting curve from real time PCR assay showed that L. kefiri, L. kefiranofaciens, L. casei, and L. paracasei were the dominant bacteria in all kefir samples while L. acidophilus, L. delbrueckii subsp. bulgaricus, L. fermentum, L. plantarum, L. amylovorus, Streptococcus thermophilus, and Saccharomyces cerevisiae were detected in a few kefir samples. Based on microscopic examination and biochemical tests, 30 of 100 bacterial isolates were confirmed to belong to the genus Lactobacillus. It was also indicated that isolated Lactobacillus species from kefir samples have potential probiotic properties. In addition, identification studies for the isolates from the kefir samples were also carried out. These isolates were identified by 16S rRNA sequencing BLAST analysis and alignment. BLAST results showed that 19 isolates had more than 97% similarity with Lactobacillus paracasei subsp. tolerans strain NBRC 15906, 5 isolates had more than 99% similarity with Lactobacillus gallinarum strain ATCC 33199, 2 isolates (k5-14 and k5-15) showed 99.21 and 98.71 % similarity of Lactobacillus zeae respectively, and 2 isolates (K4-6a and K6-3a) displayed more than 99.22 % similarity with Lactobacillus helveticus strain NBRC 15019. In addition, 2 more isolates were also identified, K6-14 which was identical to Lactobacillus rhamnosus strain NBRC 3425 with 99.45% similarity and K2-3 which showed 98.27 % similarity to Lactobacillus intestinalis strain TH4. Sequence alignment using the Clustal omega program was useful for identifıcation of some isolates

URI

https://hdl.handle.net/11511/69119

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Chemical and rheological properties of yoghurt produced by lactic acid cultures isolated from traditional Turkish yoghurt Dinçel, Sezen; Gültekin, Güzin Candan; Mert, Behiç; Department of Food Engineering (2012) Yoghurt is a fermented milk product which is produced by Streptococcus thermophilus and Lactobacillus delbrueckii spp. bulgaricus. The production of yoghurt has started in Middle East and spread all over the world. The aim of this study is to select the culture combination which is appropriate to Turkish taste and have the best yoghurt characteristics by means of post-acidification and whey separation properties, texture of gel formation, exopolysaccharide and acetaldehyde content; and to observe the effect...
The development of alkaline phosphatase based paper bioreporter for evaluation of milk pasteurization Karakaş, Ceren; Öktem, Hüseyin Avni; Department of Biotechnology (2009) Alkaline phosphatase (ALP) is a natural milk enzyme. It has been used as reporter for process controls in food industry. Since ALP denatures at pasteurization temperature (at 63°C or 72°) its detection in milk confirms the unproper pasteurization. There are different detection procedures such as colorimetric, fluorometric methods and immunoassays for ALP in milk. However, they are time consuming processes and require specific instruments and qualified staff. In this study, new, semiquantitative, disposable,...
Utilization of whey powder in the encapsulation of lactobacillus acidophilus by spray drying for the production of probiotic yogurt Değirmenci, Cansu; Gürakan, Candan; Ögel, Zümrüt Begüm; Department of Biotechnology (2017) Yogurt is a valuable functional food and has an important market worldwide. Yogurt is made by fermentation of milk with lactic cultures containing Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus. Since yogurt contains viable bacterial cultures, its shelf life related to the viability of the cultures and lactic acid formation, is a critical problem for the food industry. In order to prevent undesirable effects of artificial additives, natural additives are preferred to prolong shelf ...
Preparation and Characterization of a Novel Solid-Phase Microextraction Material for Application to the Determination of Pesticides Dizdas, Tugberk Nail; Pelit, Fusun Okcu; KORBA, KORCAN; PELİT, LEVENT; Kanik, Fulya Ekiz; Toppare, Levent Kamil; ERTAŞ, HASAN; ERTAŞ, FATMA NİL (2016-05-02) The preparation and characterization of a novel solid-phase microextraction fiber is reported with application to the determination of pesticides in fruit juice. The fiber was fabricated by electrochemically coating a stainless steel wire with a thin polymeric film of 4-(2,5-di(thiophen-2-yl)-1H-pyrrol-1-yl) benzenamine. The procedure was initiated in 10mL of acetonitrile containing 5.5mg of monomer, 0.1mol NaClO4, and 0.1mol LiClO4 by cycling the potential between -0.5 and 1.2V with a scan rate of 100mV/se...
Microencapsulation of wheat germ oil Yazicioglu, Basak; Şahin, Serpil; Şümnü, Servet Gülüm (2015-06-01) Wheat germ oil (WGO) is beneficial for health since it is a rich source of omega-3, omega-6 and tocopherol. However, as it contains polyunsaturated fatty acids, it is prone to oxidation. The aim of this study was to encapsulate wheat germ oil and determine the effects of core to coating ratio, coating materials ratio and ultrasonication time on particle size distribution of emulsions and encapsulation efficiency (EE) and surface morphology of capsules. Maltodextrin (MD) and whey protein concentrate (WPC) at...

Citation Formats

M. S. E. S. Hassan, “Detection of probiotic microorganisms using RT-PCR, and isolation, identification, probiotic properties of lactobacillus species from kefir,” Ph.D. - Doctoral Program, Middle East Technical University, 2020.