Expressing Vitreoscilla hemoglobin in statically cultured Acetobacter xylinum with reduced O 2 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 O 2 tension in gaseous phase of the culture by tightly sealing the culture tube could also enhance BC production by 70%. O 2 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 7.36 g/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 4 l disposable zip lock plastic bag with BC yield of 0.38 and concentration of 6.73 g/l.