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ABSTRACT
The objective of the present study was to study the optimization conditions for the production of xanthan by Xanthomonas campestris from pre-treated sugarcane molasses. In the study, the optimization was carried out for different parameters including pH, temperature, and incubation time for the pre-treated sugarcane molasses. The age of inoculums and time of culture growth (6, 12, 18 and 24 hrs), size of inoculums (2%, 5%, 7.5% and 10%), pH (6.6, 6.8, 7.0 and 7.2) and temperature (25°C, 28°C, 30°C, 32°C and 37°C) were studied. It was observed that the xanthan production was maximal with 7.5% (v/v) inoculums, pH. 7 at 30°C for 48 hrs. The study suggested that cane molasses is an appropriate agro-industrial substrate for xanthan gum fermentations, and further scale-up study is needed for gum production in the stirred fermenter.
Key Words:
Xanthomonas campestris Cane molasses Xanthan gum Cauliflower leaf
INTRODUCTION
Polysaccharides are important natural products usually obtained through plant sources. The manufacture of polysaccharides by the fermentation process, instead of their extraction from plant sources, is a newly developed industry (Murugesan et al. 2012, Kleinitz et al. 1989). xanthan gum is one of the polysaccharides that can be produced by culturing microorganisms belonging to the Xanthomonas genus (Sutherland 1998, Becker et al.1998). The natural synthesis in bacteria is a dual-stage method wherein first stage growth of the microorganism is ideal and in second stage biosynthesis of the polysaccharide takes place with considerably no growth of the microorganism (Amanullah et al.1998). The polysaccharide or gums with novel properties are in high demand in food processing and many industrial operations. FDA allowed use of xanthan gum for general use in foods e.g., in cream cheese as a thickening and stabilizing agent (Chi-Liang et al.1996, FDA 2020).
Xanthan gum is also widely used in the oil industry, the pharmaceutical industry, and a variety of other industries. (Hassler 1990). However, commercially procured xanthan is relatively expensive. The higher cost is due to the costly substrate such as glucose or sucrose and high purity required for use in food products. For example, in the synthesis of food-grade xanthan, almost half of the cost is capitalized in its downstream processing. The cost of large-scale xanthan synthesis can be reduced by a significant amount if we...