Ti?cari? Yoğurt Örnekleri?nden Canlı Lakti?k Asi?t Bakteri?leri?ni?n I?zolasyonu Ve Sayımı
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Dosyalar
Tarih
2015
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Selçuk Üniversitesi Fen Fakültesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Bu çalışmada, marketlerde satılan çeşitli markalara ait yoğurt örneklerinin canlı laktik asit bakteri yoğunluğu araştırıldı. Yoğurt örnekleri satın alındı ve laktik asit bakterilerinin izolasyonu ve sayımı yapıldı. Yoğurt kültürü bakterilerinden Streptococcus salivarius subsp. thermophilus’ un sayımında Terzaghi ve Sandine (1975), tarafından önerilen M17 agar (Oxoid) kullanıldı. İnoküle edilen plaklar 37oC’de 48 saat inkübe edildi ve sayımlar koloni oluşturan birim (kob)/g olarak belirtildi. Lactobacillus delbrueckii subsp. bulgaricus’un sayımında ise de Man Rogosa Sharp Agar (MRS agar, Oxoid) kullanıldı. Plaklar 37oC’de 72 saat inkübe edildi ve sayımlar kob/g olarak belirtildi. İzole edilen kolonilerin mikroskobik ve makroskobik incelemeleri yapıldı. Yoğurt örneklerinin 1 gramındaki laktik streptokokların sayısı en düşük 106 ve en yüksek 108 kob olarak sayıldı. Laktobasillerin 1 g yoğurttaki kob sayıları en düşük 105 ve en yüksek 108 olarak belirlendi. Yoğurt kültürünü oluşturan bu bakterilerin birbirine oranının 1/1 oranına yakın olduğu görüldü. Dört yoğurt markasında, bir hafta ara ile yeniden alınan ve incelenen örneklerde yapılan iki sayımda da laktobasillere rastlanmadı. Bu markaya ait yoğurt örneklerindeki laktobasillerin inhibe olması nedeni ile yoğurt standardına uygun olmadıkları, diğer örneklerde belirlenen toplam canlı laktik asit bakteri sayılarının ise yoğurt standartlarındaki sayılara yakın değerde olduğu sonucuna varıldı.
In this study, intensity of live lactic acid bacteria in yoghurt samples of various brands sold on the market were investigated. Yoghurt samples were purchased and the isolation and enumeration of lactic acid bacteria were performed. M17 agar (Oxoid) advised by Terzaghi and Sandine (1975) was used to enumeration of Streptococcus salivarius subsp. thermophilus yoghurt culture bacteria. Inoculated plates were incubated at 37oC for 48 h and counts were expressed as colony performing unit (cfu)/g. Also de Man Rogosa Sharp Agar (MRS agar, Oxoid) was used for enumeration of Lactobacillus delbrueckii subsp. bulgaricus. Plates were incubated at 37oC for 72 h and counts were expressed as cfu/g. Microscopic and macroscopic investigations of colonies which were isolated were done. The numbers of lactic streptococci in 1 g of yoghurt samples were counted as minimum 106 and maximum 108 cfu. The cfu numbers of lactobacilli in 1 g of yoghurt were determined as the lowest 105 and the highest 108 . It was seen that the ratio of these bacteria, forming yoghurt culture, were found to be close to 1/1. In both enumerations in the examined samples lactobacilli were not found in four brands of yoghurt which were re-taken for a week. It was concluded that, due to the inhibition of lactobacilli in examined samples, four brands of yoghurt were not suitable according to yoghurt standards and the total numbers of live lactic acid bacteria identified in other samples were close to the number of standard yogurt values.
In this study, intensity of live lactic acid bacteria in yoghurt samples of various brands sold on the market were investigated. Yoghurt samples were purchased and the isolation and enumeration of lactic acid bacteria were performed. M17 agar (Oxoid) advised by Terzaghi and Sandine (1975) was used to enumeration of Streptococcus salivarius subsp. thermophilus yoghurt culture bacteria. Inoculated plates were incubated at 37oC for 48 h and counts were expressed as colony performing unit (cfu)/g. Also de Man Rogosa Sharp Agar (MRS agar, Oxoid) was used for enumeration of Lactobacillus delbrueckii subsp. bulgaricus. Plates were incubated at 37oC for 72 h and counts were expressed as cfu/g. Microscopic and macroscopic investigations of colonies which were isolated were done. The numbers of lactic streptococci in 1 g of yoghurt samples were counted as minimum 106 and maximum 108 cfu. The cfu numbers of lactobacilli in 1 g of yoghurt were determined as the lowest 105 and the highest 108 . It was seen that the ratio of these bacteria, forming yoghurt culture, were found to be close to 1/1. In both enumerations in the examined samples lactobacilli were not found in four brands of yoghurt which were re-taken for a week. It was concluded that, due to the inhibition of lactobacilli in examined samples, four brands of yoghurt were not suitable according to yoghurt standards and the total numbers of live lactic acid bacteria identified in other samples were close to the number of standard yogurt values.
Açıklama
Anahtar Kelimeler
Ticari yoğurtlar, Streptococcus salivarius subsp. thermophilus, Lactobacillus delbrueckii subsp. bulgaricus, Yoğurt kalitesi, Bakteri sayımı, Commercial yoghurts, Quality of yoghurt, Bacteria enumeration
Kaynak
Selçuk Üniversitesi Fen Fakültesi Fen Dergisi
WoS Q Değeri
Scopus Q Değeri
Cilt
Sayı
41
Künye
Durak, Y., Uysal, A., Aladağ, M. O., Akın, D. (2016). Ti̇cari̇ yoğurt örnekleri̇nden canlı lakti̇k asi̇t bakteri̇leri̇ni̇n izolasyonu ve sayımı. Selçuk Üniversitesi Fen Fakültesi Fen Dergisi, (41), 83-88.
