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انتاج وتوصيف متعدد السكريات الخارج خلوي Lactobacillus plantarum من بكتريا Exopolysaccharide المعزولة محليا ودراسة فعاليته البيولوجية == Production And Characterization of Exopolysaccharide (EPS) From Locally Isolated Lactobacillus Plantarum And Studying Its Biological Activity
Author name:
بيداء مهدي عباس الغانمي
Supervisor name:
ناجح هاشم كاظم الظويهري
General topic:
Biology
Specific topic:
Microbiology - Bacteria
Degree:
Master
University:
University of Kerbala - Faculty Of Education - Department Of Biology
Language:
Arabic
University location:
Karbala
First pages:
24T3012 - p.pdf
Abstract:
Twenty - five isolates of Bacillus spp. Were isolated from 15 soil samples collected from different places in the Holly city of Kerbala, 13 isolates lactobacillus spp. Were isolated from 15 milk products and 7 isolates pseudomonas spp. The isolates were screened for their ability to produce Exopolysaccharide.The results showed that isolate number 3 (Lactobacillus lac 3) was found to give the highest production of the polymer, the isolate has been identified as lactobacillus plantarum. The optimal cultural and environmental conditions for EPS production were been identified which include using the production medium (simplified synthetic medium) containing date juice (5%) as a carbon source and yeast extract (0.2%) as a nitrogen source, the media was enhanced with a total concentration 0.9% of magnesium sulphate and potassium phosphate as mineral salts. The primary pH was adjusted to 6.5 and the inoculum size was 3%(v/v), isolates were grown under anaerobic condition at 35 Co for 24 h and the EPS extracted with ethanol 95%. Two steps were used for partial purification of the polymer as follows, the first step by using TriChloroAcitic acid (TCA) solvent and the second step by dialysis. The yields were (77.4 and 63.8)% for the two purification steps respectively. The biological activity of the EPS extraction from L. plantarum has been tested against some species of G+ve and G - ve bacteria and some fungal. The results showed that EPS extrac exhibits an inhibitory activity against Stenotrophomonas, Bacillus cereus and Proteus bacteria with an inhibition zone diameter of 23, 21, 19 mm respectively. While, there was no inhibitory effect against fungi. Antioxidant activity has also been tested, where IC50 value against ABTS free radical at 100 Mg / ml. The characterization of partially purified EPS is investigated by using Fourier Transform Infrared Spectroscopy (F.T.I.R). The molecular weight of the polymer was also measured by using viscometer and the molecular weight obtained by this technique was 2.3 *105 Dalton. The EPS extraction from selected isolate showed two spots when separated by Thin Layer Chromatography (TLC) which is analyzed as a glucose and galacto
