Kinetic models for xanthan gum production using Xanthomonas campestris from molasses

Abstract

The effects of media temperature, agitation rate and molasses concentration on the yield of fermentation in xanthan gum production process were investigated. Xanthan gum was produced in batch fermentation by Xanthomonas campestris PTCC 1473 from molasses. At 32 °C, 500 rpm and media with 30 g/l of total sugar, maximum production of xanthan gum (17.1 g/l) was achieved. For the purity of the xanthan FTIR spectrum was obtained. The identified spectrum was compared with the commercial product. In batch culture, several kinetic models for the biochemical reactions were extensively studied. The growth kinetic parameters were evaluated by unstructured model and derived from the related equations. Based on Malthus and Logistic rate equations, the maximum specific growth rate, μ max , and initial cell dry weight, X 0 , were defined. Luedeking-Piret and Modified Luedeking-Piret models were applied for the product formation and substrate consumption rates. In batch experiments, the kinetic parameters for the growth associated (m, a) and non-growth associated (n, b) parameters were determined.

Characterization and determination of antimicrobial and metal resistant profiles of Xanthomonas strains isolated from natural environments

“…Figure 2 shows the xanthan chemical structure and two typical spectra obtained for samples obtained from of 2044 and 2093 strains, which perfectly agree with previously reported spectra for xanthan obtained from X. campestri strains. [27][28][29] The more prominent bands can be associate to: O-H stretching from hydroxyl groups (3410cm -1 ); C-H stretching from aliphatic CH 2 and CH 3 moieties (2935cm -1 ); C=O stretching from carboxylic and ester moieties (1670cm -1 ); C-O-C stretching from ether linkages (1060cm -1 ) and skeleton and complex ring vibrations (570cm -1 ).…”

The Kinetics Both of Growth and Metabolite Production of X.CAMPESTRIS Using of 4% Liquid Sugar Substrate From Cassava Hydrolisate

“…Based on Figure 1 it can be seen that X.campestris requires adaptation time to growth medium, in this case nutrient broth (NB) about 22 hours (11 th sampling) at 28 0 C. According to Gilani et al (2011) X. campestris requires adaptation to the environment around 24-48 hours, using YMB (yeast malt broth) medium. Furthermore, X. campestris has begun to adapt to its environment, which can be observed from a significant increase in cellular or biomass weight.…”

“…Based on Figure 3 showed that a linear regression line was Y = 0.043x -1,194, with R 2 = 0,924, tangent value indicating a specific growth rate (μ) = X. campestris of 0.043 hour -1 . Gilani et al (2011) reported that using YME medium, obtained growth rate specific of X. campestris between 0,087-0,089 hour -1. The value of μ from this study was still relatively low, it showed that cell growth rate was still slow, ie the amount of reproduction of cells X. campestris was 0.043 grams per hour.…”

Model-based estimation of optimal dissolved oxygen profile in Agrobacterium sp. fed-batch fermentation for improvement of curdlan production under nitrogen-limited condition

“…For extracellular polysaccharide production, the logistic and Luedeking-Piret equations were used to describe cell growth kinetics, substrate consumption, and polysaccharides formation for xanthan gum and gellan gum [13,29,30]. Xanthan gum or gellan gum fermentation is a growth-associated process.…”