الفهرس 
Microbial PolysaccharidesOnly 14 pages are availabe for public view
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Abstract
Xanthan gum is the most important industrial microbial polysaccharide produced by the bacterium Xanthomonas campestris. It has attracted the attention because it has a many applications as a thickener, stabilizer and emulsifier as a result of its unique rheological properties in food and nonfood sector. The results obtained could be summarized in 3 parts as follows: Part 1: Optimization conditions for production of xanthan gum proved that: 1. Sucrose and glucose were the best carbon sources for production of xanthan gum which gave higher xanthan yield 21.6 and 9.2 g/L respectively in liquid medium and 13.0 and 8.0 g/L respectively in solid agar medium. 2. Peptone and tryptone were the best organic nitrogen sources in liquid medium for production of xanthan gum which increasing the yield of xanthan to be 36 and 25 g/L respectively. 3. Di ammonium hydrogen phosphate was the best inorganic nitrogen source for both liquid and solid agar medium yielding 20 and 4.2 g/L of xanthan respectively. 4. Cystine was the best amino acid for the production of xanthan gum by Xanthomonas campestris in liquid medium yielding 35 g/L. However, alanine was the best amino acid in solid agar medium yielding 7.51 g/L.5. The optimal pH value for production of xanthan gum was neutral pH. 6. The production of xanthan gum by X. campestris in liquid medium was higher than in solid agar medium.