Optimization of Xanthan Gum Production by Demerara Sugar Using Response Surface Methodology

Abstract

Xanthan gum (XG) production using three Xanthomonas sp. strains (290, 472, and S6) was evaluated by applying a 23 full factorial central composite design response to study the interactive effects of the fermentation medium component concentrations as parameters to determine the efficiency of the gum production in batch experiments. The experimental variables were the carbon source (demerara sugar or sucrose), potassium phosphate dibasic, and magnesium sulfate. Experimental results showed the K2HPO4 concentration as the important parameter for XG production by using Xanthomonas axonopodis pv. manihotis IBSBF 290 and X. campestris pv. campestris IBSBF 472, while for the Xanthomonas sp. S6 strain, the MgSO4∙7H2O concentration was the determining factor in XG production using demerara sugar or sucrose as a carbon source. The strains of Xanthomonas 472 and S6, using demerara sugar and higher concentrations of salts, exhibited a higher yield of XG (36 and 32%) than when using sucrose and the same concentration of salts. The experimental outcomes highlighted demerara sugar as a suitable and efficient alternative carbon and micronutrient source for XG production. Despite the bacterial strain influence, the medium composition is crucial for this fermentation process. Therefore, the evaluated salts are important factors for XG production, and the demerara sugar can partially replace this mineral salt requirement as indicated by the face-centered composite experimental design due to its chemical composition. Overall, demerara sugar provides promising properties for XG production.

Production of Bacterial Exopolysaccharides: Xanthan and Bacterial Cellulose

“…Like other EPSs, xanthan and BC yield and quality depend on many parameters and variables, including culture medium composition, temperature, pH, oxygen transfers, agitation rate, inoculum volume, cultivation method, fermentation duration, etc. Statistical methods have been applied systematically to optimize xanthan and BC production parameters [89][90][91][92][93][94][95][96][97][98]. A recent interesting review by Rocha et al (2023) presents the main BC biosynthesis processes and strategies to optimize its production at industrial scale for the purposes of bioeconomy [99].…”

“…However, they are not economically viable for industrial scale production either [98]. Many researchers point out that the most promising medium for producing xanthan is sucrose supplemented with salts [92,109]. Also, starches (corn starch, potato starch), which have a relatively high cost, can serve as a source of carbon for xanthan production [110].…”

“…Microcrystalline cellulose is present in different agro-industrial wastes such as walnut shells, corncob, and sugarcane bagasse [205]. Moreover, to make xanthan production cost-effective, agricultural and food wastes such as tapioca pulp [147], waste bread [149], kitchen waste [150], jackfruit seed powder [151], cocoa husk [153], fermenting shrimp shell [161], sugarcane bagasse [206], rice bran [207], chicken feathers [208], coconut shell, potato crop [209], winery wastewater [210], and demerara sugar [92] were used.…”

Investigation of the influence of xanthan on mozzarella cheese characteristics focusing on its antimicrobial effect

“…Response surface methodology (RSM) is a statistically efficient appliance for an ideal procedure when the unconnected variables have a mutual influence on the in-demand return [ 8 , 9 ]. A preferable model in RSM is the central composite design (CCD), which is malleable and efficient in supplying enough data on the variables, influences, and overall trial mistakes, even with a smaller number [ 10 ].…”