The Effect of Dekkera bruxellensis Concentration and Inoculation Time on Biochemical Changes and Cellulose Biosynthesis by Komagataeibacter intermedius .

Bacterial Cellulose (BC) is a biopolymer with numerous applications. The growth of BC-producing bacteria, Komagataeibacter intermedius , could be stimulated by Dekkera bruxellensis , however, the effect on BC yield needs further investigation. This study investigates BC production and biochemical changes in the K. intermedius-D. bruxellensis co-culture system. D. bruxellensis was introduced at various concentrations (10 3 and 10 6 CFU/mL) and inoculation times (days 0 and 3). BC yield was ~24% lower when D. bruxellensis was added at 10 3 CFU/mL compared to K. intermedius alone (0.63 ± 0.11 g/L). The lowest BC yield was observed when 10 3 CFU/mL yeast was added on day 0, which could be compromised by higher gluconic acid production (10.08 g/L). In contrast, BC yields increased by ~88% when 10 6 CFU/mL D. bruxellensis was added, regardless of inoculation time. High BC yield might correlate with faster sugar consumption or increased ethanol production when 10 6 CFU/mL D. bruxellensis was added on day 0. These results suggest that cell concentration and inoculation time have crucial impacts on species interactions in the co-culture system and product yield.