Utilization of wastewaters from red wine technology for xanthan production in laboratory bioreactor

Abstract

Wastewaters generated during the red grape processing into wine have notable negative environmental impact because they are usually discharged in unpurified form. Winery wastewaters treatments are more problematic compared with treatment of waste from other agro-food industry because of winemaking seasonality. Considering that there is an increasing demand for wines, especially red wines, the major problem in countries with growing wine industry is sustainable management of fluctuating quantity of wastewater with different content of organic and inorganic pollutants, as well as compounds that contribute to dark color. This study was carried out to investigate the potentiality of utilization of wastewaters generated in separate stages of red wine production for xanthan biosynthesis by Xanthomonas campestris ATCC 13951. The bioprocess success was evaluated based on the produced xanthan amount and degree of nutrients conversions. The obtained results suggest that wastewaters from red wine technology represent potential raw materials for industrial xanthan production. Novelty Impact Statement In this study, the valorization of wastewaters, generated separately in different stages of red wine production, in biotechnological process was investigated for the first time. The xanthan biosynthesis by Xanthomonas campestris ATCC 13951 is proposed as a sustainable and long-term option for utilization of wastewaters from red wine technology due to high productivity of applied producing strain and simultaneous significant pollution level reduction, which are confirmed by separated biopolymer quantity (9.24–16.46 g/L) and relatively high values of nutrients conversions (38.41–74.69% for sugars, 22.34–49.68% for total nitrogen and 64.08–70.39% for total phosphorus). The present study provides reliable data about efficacy of biotechnological utilization of wastewaters from red wine technology that can be used for further investigations, which are necessary for industrialization of examined bioprocess.