Xanthan gum production and rheological behavior using different strains of Xanthomonas sp (original) (raw)
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Xanthan gum production of Xanthomonas spp. Isolated from different plants
Food Science and Biotechnology, 2010
Xanthan gum were produced from the following Xanthomonas strains; standard strain Xanthomonas campestris NRRL B-1459 and isolated strains Xanthomonas arbicola pv. juglandis, Xanthomonas axonopodis pv. vesicatoria, Xanthomonas axonopodis pv. begonia, Xanthomonas axonopodis pv. dieffenbachia. The viscosity features of the xanthan gums obtained were determined at 25–80°C with different pH values and were compared to commercial xanthan gum. Our results indicate that X. arbicola pv. juglandis showed the highest productivity (8.22±1.52 g/L gum). This was followed by X. axonopodis pv. begonia (7.74±1.30 g/L gum), and the control bacterial strain X. campestris NRRL B-1459 (7.46±0.28 g/L gum). X. axonopodis pv. vesicatoria showed the lowest productivity (6.40±0.55 g/L gum). No xanthan gum could be obtained from X. axonopodis pv. dieffenbachia. Xanthan gum produced by X. axonopodis pv. vesicatoria showed the highest viscosity value (428 mPa·sec at 1% solution) in all Xanthomonas strains isolated from plants.
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Biosynthesis of Xanthan Gum from Fermenting Shrimp Shell: Yield and Apparent Viscosity
With the aim of producing xanthan gum, the effects of an aqueous shrimp shell extract (SSAE) as the source of carbon and nitrogen on the yield and apparent viscosity of the gums produced by fermentation using three native strains of Xanthomonas campestris were studied. It was found that the SSAE contained 89.75% moisture, 0.054% ash, 8.069% protein, 0.787 lipids, and 1.337% carbohydrates. Media containing different concentrations of SSAE and supplemented with urea (0.01%) and phosphate (0.1%) were fermented in a shaker, and the results obtained were compared with those obtained from sucrose (control) with the same supplementation and fermentation conditions. Strain 1182 showed the highest yield (4.64 g⋅L −1) and viscosity (48.53 mPa⋅s), from the medium containing 10% (w/v) of SSAE. These values were higher than those obtained from the control medium containing sucrose. Shrimp shell is a low cost residue that can be bioconverted into products of high added value such as xanthan gum.
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Hybrid modeling of xanthan gum bioproduction in batch bioreactor
Bioprocess and Biosystems Engineering
This work is focused on hybrid modeling of xanthan gum bioproduction process by Xanthomonas campestris pv. mangiferaeindicae. Experiments were carried out to evaluate the effects of stirred speed and superficial gas velocity on the kinetics of cell growth, lactose consumption and xanthan gum production in a batch bioreactor using cheese whey as substrate. A hybrid model was employed to simulate the bio-process making use of an artificial neural network (ANN) as a kinetic parameter estimator for the phenomenological model. The hybrid modeling of the process provided a satisfactory fitting quality of the experimental data, since this approach makes possible the incorporation of the effects of operational variables on model parameters. The applicability of the validated model was investigated, using the model as a process simulator to evaluate the effects of initial cell and lactose concentration in the xanthan gum production.
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2018
S Xanthan gum, a heteropolysaccharide produced by a bacteria species, Xanthomonas campasteris from a carbohydrate rich source, widely used in food and pharmaceutical industries. This study compares the yield and quality of xanthan gum produced from two sources of mango and orange peel using the bacteria. The bacteria strain was isolated from infected lettuce leaves and fermentation of waste materials was carried out in 250 ml flasks for 72 hours at 32 o C and 150 rev/min in a Water-bath shaker. The xanthan gum produced was recovered from the media by precipitation, centrifugation and drying. The dried gum was dissolved in water and the viscosities were measured at shear rate in the range of 1-5 rpm at different temperatures ranging between 25-60 o C. The results showed that the yield of Xanthan gum from the mango extract (15 g/L) was higher than that obtained from the orange extract (8 g/L). The two samples were tested for pseudoplasticity and the viscosity obtained for 1 rpm and at room temperature for 1.5% wt/vol. gum were 1782 cP and 1200 cP for the mango extract and the orange extract respectively. The stabilities of the two samples of gum were tested by the addition of various quantities of MgSO4 salt and the gum from the mango extracts was adjudged to be more stable.
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