title: High concentration cultivation of Bifidobacterium bifidum in a submerged membrane bioreactor.
abstract: In batch cultures, after 25 h, the maximum cell mass of Bifidobacterium bifidum BGN4 was 4.5 g/L, and the maximum cell count was 3.0 x 10(9) cfu/mL at pH 6.0 and 50 g/L sucrose. To increase the viable counts of bifidobacteria, cell retentive culture was applied using a submerged membrane bioreactor with suction and gas sparging. The maximum mass, count, and productivity of the cells after 36 h were 12.0 g/L, 2.2 x 10(10) cfu/mL, and 6.1 x 10(8) cfu/mL x h, respectively, at the feeding (dilution) rate of 120 mL/h (0.06 h-1) in the feeding medium. The accumulated levels of organic acids and ammonium ions at the end of the cultivation were 1.5 and 1.0 g/L, respectively. The viable counts and volumetric productivity of the cells after the cell retentive culture were 7.3- and 5.1-fold higher, respectively, than the values obtained during batch culture. These high viable counts and volumetric productivities were obtained by maintaining lower concentrations of organic acids and ammonium ions so that the growth of B. bifidum BGN4 was not inhibited. The submerged membrane bioreactor produced the highest viable counts of B. bifidum without membrane fouling and cell damage.
authors.affiliation: Department of Bioscience and Biotechnology, Konkuk University, Seoul 143-701, South Korea.
authors.forename: Soun-Gyu
authors.initials: SG
authors.lastname: Kwon
authors.forename: Ju-Wan
authors.initials: JW
authors.lastname: Son
authors.forename: Hye-Jung
authors.initials: HJ
authors.lastname: Kim
authors.forename: Chang-Su
authors.initials: CS
authors.lastname: Park
authors.forename: Jung-Kul
authors.initials: JK
authors.lastname: Lee
authors.forename: Geun Eog
authors.initials: GE
authors.lastname: Ji
authors.forename: Deok-Kun
authors.initials: DK
authors.lastname: Oh
mesh_terms: D001644:Bifidobacterium / Q000166:cytology* / Q000254:growth & development*; D019149:Bioreactors / Q000382:microbiology*; D018929:Cell Culture Techniques / Q000295:instrumentation* / Q000379:methods; D049109:Cell Proliferation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007218:Industrial Microbiology / Q000295:instrumentation* / Q000379:methods; D008567:Membranes, Artificial
chemical_list: D008567:Membranes, Artificial