Xanthan biosynthesis by Xanthomonas campestris ATCC 13951 on wastewaters from white grape processing

Abstract

Summary:Wastewaters from grape processing in wineries are characterized by large seasonal fluctuations in volume and composition, and are often discarded into environment with little or no treatment. The biotechnological production of valuable products is the most promising alternative for reducing the negative environmental impact and recycling these effluents. Results from previous study show that mixed winery wastewaters, after additional optimization of the medium preparation, may be a suitable raw material for industrial xanthan production. Therefore, the aim of this work was to examine the possibility of xanthan production by Xanthomonas campestris ATCC 13951 on mixed wastewaters from different stages of white grape processing in winery with initial sugars content of 20 g/L. In addition to the media characteristics and indicators of biopolymer quality, raw xanthan yield and degree of sugars conversion into product were determined in order to examine the success of performed bioprocess. The results for biopolymer yield (14.66 g/L) and sugars conversion into desired product (70.21%) obtained in applied experimental conditions confirm that wastewaters from white grape processing have a great potential to be used as a substrate for xanthan biosynthesis.

Effect of carbon sources on xanthan production by Xanthomonas spp. isolated from pepper leaves

“…For a Newtonian fluid, flow behavior index is equal to 1, greater than 1 for a dilatant and less than 1 for a pseudoplastic fluid (Björn et al, 2012). In this research, values of flow behavior index for cultivation media obtained after biosynthesis were in the range of 0.3900-0.5377 (Table 2), which is similar to the results from available literature (Rončević et al, 2017). Considering that these data are different in relation to the values of the same parameter determined before inoculation (0.4079-0.5549; see Table 1), it can be assumed that metabolic activity of all used producing microorganisms occurred under the applied experimental conditions on all investigated media.…”