Sarhadi Aval, Yegane (2020) Production, purification and physicochemical properties of Exopolysaccharide from lactobacillus pentosus. Masters thesis, University of Zabol.
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Production, purification and physicochemical properties of Exopolysaccharide from lactobacillus pentosus.pdf Download (331kB) | Preview |
Abstract
Exopolysaccharides (EPSs) are high molecular weight biopolymers made up of sugar units that are released into the environment by microorganisms. In this study, first the exopolysaccharide obtained from L.Pentosus MT.ZH693 and L.Fermentum MT.ZH893 was produced, extracted and purified under optimal culture conditions. The obtained exopolysaccharides were then subjected to NMR, water holding capacity, water solubility index, anti-biofilm activity, rheological test and inhibition of DPPH radical activity. exopolysaccharide obtained from L.Pentosus MT.ZH693 under optimal culture medium conditions (glucose: 4.11% w/v, sucrose: 3.47% w/v, yeast extract: 3% w/v, peptone: 3% w/v, time: 30.92 h, temperature: 40˚c, inoculation size:3.16% v/v and pH: 7) and exopolysaccharide from strain L. Fermentum MT.- ZH893 under optimal conditions (glucose: 4.12% w/v, sucrose:1.78% w/v, yeast extract: 2.64 % w/v, peptone: w/v 0.01% Time: 66.48 h, temperature:39.55˚c, inoculation size: 1.97 % v/v and pH: 5.83) were produced and then purification and drying steps were performed by freeze-drying system. The results showed that the amount of exopolysaccharide obtained from strain L. Pentosus MT.ZH693 0.225 mg/- ml and its biomass amount 0.405 mg/ml and as well as the amount of exopolysaccharide produced by strain L.Fermentum MT.ZH893 mg/ml 0.181 and biomass value 0.337 mg/ml. The NMR spectrum of exopolysaccharides generally indicates the presence of anomeric protons, cyclic protons, and alkyls. Aqueous solubility index and water holding capacity EPS for L. Pentosus MT.ZH693 was27.14% and 170% and for L. Fermentum MT.ZH893 This value is 16.84% and130%. The results of anti-biofilm test indicate that the highest inhibition of EPSs was on Pseudomonas aeruginosa strain and the lowest inhibition was on Salmonella typhimurium strain. Examination of the EPS frequency change rheological test also showed that the EPSs produced by both strains behaved like a fluid. The results of DPPH indicate that with increasing the concentration of exopolysaccharide, the level of inhibitory activity also increases. The highest rate of EPS inhibition resulted from strain L. Fermentum MT.ZH893 was64.36% and the highest rate of EPS inhibition by strain L. Pentose MT.ZH693 was 58.83%. In other words, the resulting physicochemical properties indicate that EPS can be well used in the food industry as an additive, natural stabilizer, viscose and water retaining agent.
| Item Type: | Thesis (Masters) |
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| Uncontrolled Keywords: | Exopolysaccharide, Biopolymer, Antioxidant activity, Rheology test |
| Subjects: | Q Science > QH Natural history > QH301 Biology |
| Depositing User: | Mrs najmeh khajeh |
| Date Deposited: | 23 Oct 2021 07:25 |
| Last Modified: | 23 Oct 2021 07:25 |
| URI: | http://eprints.uoz.ac.ir/id/eprint/2854 |
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