Fructose cultivation media

The media outlined for the cultivation of lactic acid bacteria are the apple juice Rogosa medium (King and Beelman, 1986) and the tomato juice-glucose-fructose-malate medium (Izuagbe et al., 1985). These media use either apple juice or tomato juice serum to provide the so-called tomato juice factor (Section 2.3). Liver extract or concentrate has a number of vitamins that improves bacterial growth and is available from Sigma Chemical Company. Both media can be made selective against Sac-charomyces by the addition of cycloheximide. 

A pH-stat fed-batch strategy was applied for the culture of transformant Ralstonia eutropha REZ coexpressing the phbC and zwf genes. It was cultivated in a minimal medium followed by feeding 10 g/1 of fructose and valerate to maintain a pH level of 7.0. This strategy resulted in the production of a 60.1% poly(3HB-co-3HV) copolymer and cell mass of 14 g/1. The 3HV monomer composition reached 71.9 mol% [18]. 

Fig. 11.2 (a-c) Growth of G. oxydans deletion strains (open symbols) and the parent strain G. oxydans hupp (filled symbols) on mannitol hgnd (a) hgnd zwf (b) hedd-eda (c). (d-f) Substrate consumption and product formation of G. oxydans deletion strains (dashed lines) and the reference strain hupp (closed lines) hgnd (d) hgnd zwj (e) hedd-eda (f). Cells were cultivated in mannitol medium at 15 % dissolved oxygen at pH 6. Mean values and standard deviations of three independent cultures are shown. Mannitol (red), fructose (green), 5-ketofructose (blue), acetate (yellow). (Modified from Richhardt et al. 2012)... 

---