Expressing Vitreoscilla hemoglobin in statically cultured Acetobacter xylinum with reduced O2 tension maximizes bacterial cellulose pellicle production

Abstract: Vitreoscilla hemoglobin (VHb) was constitutively expressed in Acetobacter xylinum to enhance bacterial cellulose (BC) production. A pronounced enhancement of BC production in static culture was observed. Reducing O2 tension in gaseous phase of the culture by tightly sealing the culture tube could also enhance BC production by 70%. O2 tension in gaseous phase reduced from 21 to 15% in the sealed and static culture of VHb-expressing A. xylinum after 7 days cultivation, while 7.36g/l of BC with yield of 0.44 were obtained. BC pellicle production by VHb-expressing A. xylinum was successfully scaled-up in a sealed 4l disposable zip lock plastic bag with BC yield of 0.38 and concentration of 6.73g/l. [Copyright &y& Elsevier]