Simultaneous production of polyhydroxyalkanoate and xanthan gum: From axenic to mixed cultivation.

• PHA (3.39 g L−1) and XG (1.77 g L−1) productions were individually optimized. • PHA (6.43 g L−1) and XG (1.98 g L−1) co-culture productions were accomplished. • Co-culture bioconversions of palm oil promoted higher PHA production. • X. campestris and C. necator synergism is dependent to the bioconversion conditions. • Polymers properties were altered due to the culture configurations. In the present study, mixed and axenic submerged cultures of Cupriavidus necator and Xanthomonas campestris were performed for simultaneous and individual PHA and XG productions using palm oil (Elaeis guineensis) as substrate. Rotational Central Compound Design (RCCD) was successfully used in the optimization of individual productions of PHA (3.39 g L−1, Mw = 692.6 kDa) and XG (1.77 g L−1, Mw = 36.6 × 105 kDa). Novel simultaneous production of PHA (6.43 g L−1, Mw = 629.2 kDa) and XG (1.98 g L−1, Mw = 25.0 × 105 kDa), executed in bacterial co-cultivation, revealed to be a successful strategy to increment polymer synthesis, especially PHA. XG bioconversions followed a general trend of lower production in co-culture. Culture configurations also altered polymers properties and characteristics. [ABSTRACT FROM AUTHOR]