Doğal üretilen küflü peynirden izole edilen bazı laktik asit bakterilerinin aflatoksin B1 ve aflatoksin M1 üzerine etkisinin araştırılması
Küçük Resim Yok
Tarih
2008
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Ege Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Aflatoksinler, bazı Aspergillus türlerinin ürettiği, toksisitesi yüksek ikincil metabolitlerdir. Süt ürünlerinde de en çok rastlanan mikotoksinler arasında yer almaktadırlar. Gıdaların ve yemlerin aflatoksinlerle kontamine olması büyük ekonomik kayıplara neden olmaktadır. Bu gıdalar ayrıca insan sağlığını da tehdit etmektedir. Aflatoksinlerle kontaminasyon kaçınılmaz olduğundan kontamine olmuş gıdaların detoksifikasyonu büyük önem taşımaktadır. Birçok araştırmacı mikroorganizmalarla detoksifikasyonun en uygun yöntem olduğu görüşünü savunmaktadır. 1966 yılından bu yana mikotoksinlerin, özellikle de aflatoksinlerin mikroorganizmalarla detoksifikasyonu ile ilgili birçok çalışma yapılmış ve bu çalışmalarda birçok mikroorganizma denenmiştir. Laktik asit bakterileri ile yapılan çalışmaların sonuçları da umut vericidir. Bu çalışmada, aflatoksin M1'in parçalanmasında, aflatoksin B1' in ise parçalanması ve/veya oluşumunun önlenmesinde etkili laktik asit bakteri tür ve suşlarının belirlenmesi amaçlanmıştır.Konya ilinden toplanan küflü peynir örneklerinden izole edilen 179 adet laktik asit bakterisi, fenotipik ve genotipik yöntemler kullanılarak tanımlanmışlardır. Lactobacillus brevis, Lactobacillus plantarum, Lb. paracasei / Lb. casei, Enterococcus faecium, Enterococcus faecalis, Enterococcus durans, Pediococcus parvulus oldukları belirlenen bu izolatlar arasından bazıları seçilerek, aflatoksin M1'e, aflatoksin B1, B2, G1, G2'ye ayrıca A. falvus ve A.parasiticus NRRL 2999'un gelişimine ve aflatoksin üretimine etkileri besiyeri ortamında incelenmiştir. Bakterilerin aflatoksin M1'e etkilerinin olmadığı, aflatoksin B1, B2, G1, G2 `ye ise önemsiz düzeyde olduğu belirlenmiştir. Ortamda canlı bulundukları zaman A. flavus ve A. parasiticus'un gelişim ve toksin üretimini belli bir süre engelledikleri tespit edilmiştir. Bu durumun bakterilerin ürettiği herhangi bir metabolitten değil tamamen mikroorganizmalar arasındaki rekabetten kaynaklandığı belirlenmiştir. Bu bakterilerden oluşturulan kültürle üretilen peynirde aynı etki görülmemiştir
Aflatoxins are highly toxic seconder metabolites produced by some Aspergillus spp. Among the mycotoxins aflatoxins are the most prevalent. Foods and feeds contaminated with aflatoxins cause big economical losses and they may also pose a health risk to humans. As the contamination with aflatoxins is unavoidable, detoxification of contaminated foods and feeds is very important. Different physical and chemical methods have been recommended for detoxification of aflatoxin-contaminated food and feed. Nevertheless, only a few of them have been accepted for practical use. Many workers in the field are of opinion that the best solution for detoxification should be degradation by selected microorganisms. Since 1966 many researches have been done in this field and many microorganisms have been tested. Results of the studies held with lactic acid bacteria are very promising. In this study, determination of lactic acid bacteria species and strains that have ability to degrade aflatoxin M1 and aflatoxin B1 and/or to inhibit production of aflatoxin B1 is aimed.179 lactic acid bacteria, isolated from mouldy cheese samples, collected from Konya region have been identified by using phenotypic and genotypic methods. Isolates were identified as Lactobacillus brevis, Lactobacillus plantarum, Lb. paracasei / Lb. casei Enterococcus faecium, Enterococcus faecalis, Enterococcus durans and Pediococcus parvulus. Effects of some strains among these lactic acid bacteria, on growth and aflatoxin production of A. flavus and A. parasiticus NRRL 2999, as well as aflatoxin B1, B2, G1, G2 and aflatoxin M1 have been investigated in appropriate growth mediums. It was determined that these lactic acid bacteria were not effective against aflatoxin M1 and not so effective against aflatoxin B1, B2, G1, G2. In growth mediums, it has been noticed that they have reduced growth and aflatoksin production of A.flavus and A.parasiticus for a short period only when they were viable. It has been concluded that this situation is only the result of microbial competition and there is no any other factor such as inhibitor metabolites. The same effect has not been observed in the cheese which has been produced by using these bacteria as starter culture.
Aflatoxins are highly toxic seconder metabolites produced by some Aspergillus spp. Among the mycotoxins aflatoxins are the most prevalent. Foods and feeds contaminated with aflatoxins cause big economical losses and they may also pose a health risk to humans. As the contamination with aflatoxins is unavoidable, detoxification of contaminated foods and feeds is very important. Different physical and chemical methods have been recommended for detoxification of aflatoxin-contaminated food and feed. Nevertheless, only a few of them have been accepted for practical use. Many workers in the field are of opinion that the best solution for detoxification should be degradation by selected microorganisms. Since 1966 many researches have been done in this field and many microorganisms have been tested. Results of the studies held with lactic acid bacteria are very promising. In this study, determination of lactic acid bacteria species and strains that have ability to degrade aflatoxin M1 and aflatoxin B1 and/or to inhibit production of aflatoxin B1 is aimed.179 lactic acid bacteria, isolated from mouldy cheese samples, collected from Konya region have been identified by using phenotypic and genotypic methods. Isolates were identified as Lactobacillus brevis, Lactobacillus plantarum, Lb. paracasei / Lb. casei Enterococcus faecium, Enterococcus faecalis, Enterococcus durans and Pediococcus parvulus. Effects of some strains among these lactic acid bacteria, on growth and aflatoxin production of A. flavus and A. parasiticus NRRL 2999, as well as aflatoxin B1, B2, G1, G2 and aflatoxin M1 have been investigated in appropriate growth mediums. It was determined that these lactic acid bacteria were not effective against aflatoxin M1 and not so effective against aflatoxin B1, B2, G1, G2. In growth mediums, it has been noticed that they have reduced growth and aflatoksin production of A.flavus and A.parasiticus for a short period only when they were viable. It has been concluded that this situation is only the result of microbial competition and there is no any other factor such as inhibitor metabolites. The same effect has not been observed in the cheese which has been produced by using these bacteria as starter culture.
Açıklama
Anahtar Kelimeler
Gıda Mühendisliği, Food Engineering, Mikrobiyoloji, Microbiology, Ziraat, Agriculture, Laktik asit bakterileri, Lactic acid bacteria, Mikotoksinler, Mycotoxins
