S518 : Isolation and Molecular Characterization of Lactic Acid Bacteria From Shahrood City Traditional Dairy Products
Thesis > Central Library of Shahrood University > Agricultural Engineering > MSc > 2019
Authors:
Abstarct: In the present study,the traditional dairy products included cheese, yoghurt, dough and dried whey in various rural eras of shahrood province like Calpoush, Kalate khij and Mojen were isolated to considere to hygiene standard condition. The Single colony of suspicious acid lactic bacteria which were grown in central MRS agar were selected for further identification. Diagnosis tests and macro and micro form of bacteria were applied to initially recognize the species, subsequently 16S rRNA was used to precisely confirm species obtaining from previous examination. The results revealed that the isolated bacteria from Kalate khij dough were highly similar to Lactobacillus Delbruckii SB7,Lactobacillus Delbruckii-bulgaricus TW49-1, the bacteria isolated from Kalpoush dough was so similar to Lactobacillus Paracasei Lb37 and Lactococcus lactis-NCIM 2114. The similar species of Lactobacillus Mocosae-BJ18-2 and Lactobacillus Delbruckii SkB1083 were also detected in kalate khij yoghurt. ε poly l lysine produced was also analyzed in all isolated bacteria. Initial experimentation indicated that Lactobacillus Delbruckii-bulgaricus obtained from kalate khij dough was determined as a good source of ε-poly l lysine. Carbon (glucose) and protein (soy bean powder) sources as variable factors were optimized using response surface method for higher Ɛ- poly-l- lysine production. In optimal condition 205 ppm of this vital component was attained after 3 days of fermentation time which was so close to predicted value obtained by RSM (199.22). The model indicated that a reduction in two variable factors had a positive effect on Ɛ- poly-l- lysine. The highest quantities of Ɛ- poly-l- lysine was obtained in the medium containing 26.03 gr/l glucose & 6.28 gr/l soy bean powder.
Keywords:
#Lactic acid bacteria #ε-poly l lysine mextabolit #NCBI #RSM model. Link
Keeping place: Central Library of Shahrood University
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Keeping place: Central Library of Shahrood University
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