Preparation of Komagataeibacter xylinus inoculum for bacterial cellulose
biosynthesis using magnetically assisted external-loop airlift
bioreactor
Abstract
The aim of this study was to demonstrate the applicability of a novel
magnetically-assisted external-loop airlift bioreactor (EL-ALB),
equipped with RMF generators for the preparation of Komagataeibacter
xylinus inoculum during three-cycle repeated fed-batch cultures, further
used for bacterial cellulose (BC) production. The fermentation carried
out in the RMF-assisted EL-ALB allowed to obtain an inoculum of more
than 200x higher cellular density compared to classical methods of
inoculum preparation. The inoculum obtained in the RMF-assisted EL-ALB
was characterized by a high and stable metabolic activity during
repeated batch fermentation process. The application of the RMF-assisted
EL-ALB for K. xylinus inoculum production did not induce the formation
of cellulose-deficient mutants. It was also confirmed that the ability
of K. xylinus to produce BC was at the same level (7.26 g/L of dry
mass), regardless of inoculum age. Additionally, the BC obtained from
the inoculum produced in the RMF-assisted EL-ALB was characterized by
reproducible mechanical strength, nanostructure and total crystallinity
index. The results obtained in this study may find multiple applications
in any biotechnological processes requiring a high-quality bacterial
inoculum.