Optimisation of xanthan production on glycerol-based medium using response surface methodology
- PDF / 1,047,072 Bytes
- 11 Pages / 595.276 x 790.866 pts Page_size
- 62 Downloads / 182 Views
ORIGINAL PAPER
Optimisation of xanthan production on glycerol‑based medium using response surface methodology Zorana Rončević1 · Bojana Bajić1 · Vanja Vlajkov1 · Siniša Dodić1 · Jovana Grahovac1 · Aleksandar Jokić1 · Jelena Dodić1 Received: 25 April 2019 / Revised: 6 March 2020 / Accepted: 26 June 2020 © Associação Brasileira de Engenharia Química 2020
Abstract Xanthan is one of the most important biopolymers characterised by a high commercial value. Since the availability of essential nutrients influences its biosynthesis, the aim of this study was the optimisation of carbon, organic and inorganic nitrogen content in glycerol-based medium employing response surface methodology. The cultivation of strain Xanthomonas campestris ATCC 13951 was carried out under appropriate conditions on media with glycerol, peptone and ammonium-nitrate formulated according to Box-Behnken design ( 33), while the desirability function approach was used for determination of optimal nutrient levels. The final model predicts that the maximal amount of xanthan (12.95 g/L) is produced when the initial contents of glycerol, peptone and ammonium-nitrate in the medium are 32.96 g/L, 0.55 g/L and 0.73 g/L, respectively. To minimize the residual nutrient content and therefore the costs of effluent processing, additional optimisation was performed. In order to validate the optimisation model developed and examine the bioprocess success with crude glycerol as the sole carbon source, additional experiments were performed. The results represent reliable information for further investigations. Keywords Bioprocess · Xanthan production · Medium composition · Modelling · Optimisation
Introduction Microbial polysaccharides, an important class of polymeric and renewable materials, are characterised by an unique combination of functional and physical–chemical properties, as well as rheological and film-forming behaviour, which makes them suitable for a wide range of commercial applications (Alves et al. 2010; Freitas et al. 2009). Industrial-scale production has been developed for only several biopolymers due to high manufacturing costs that are mainly related to the price of the carbon sources used for cultivation media preparation (Alves et al. 2011; Freitas et al. 2011; Giavasis et al. 2013; Sutherland 2001). Xanthan or xanthan gum is one of the most important microbial polysaccharides biosynthesised by Xanthomonas campestris and by other Xanthomonas species (Palaniraj and Jayaraman 2011). Pseudoplastic behaviour and stability over * Zorana Rončević [email protected] 1
Department of Biotechnology and Pharmaceutical Engineering, Faculty of Technology Novi Sad, University of Novi Sad, Bulevar cara Lazara 1, 21000 Novi Sad, Serbia
a wide range of temperature and pH make this biopolymer suitable for application in different fields of food and nonfood industries (Becker et al. 1998). Xanthan production involves two steps, first bacterium cultivation on medium which enhances biomass growth, and second stimulation xanthan biosynthesis by usi
Data Loading...
