Table 4

Biofilm formation characteristics of Clostridium acetobutylicum/C. beijerinckii onto various supports




C. acetobutylicum culture

- Adsorption is quick

- Biomass layers (biofilms) become visible in 3–4 days time

- Between day 2 and 4, the culture produces polysaccharide in high concentrations (2.04 gL-1 broth as compared to 0.95 gL-1 broth from day 5 to 30)

- Once initial layers appear, biomass accumulation is quick

- Desorption does not occur at high dilution rates

- < than 25% cells were desorbed when adsorbed cell particles were agitated at 200–300 rpm (in shake flasks on shaker) at pH 2.7 for 18–24 h at 30°C

- During initial stages (2–4 days) the culture produced high concentrations of acids (~6–9 gL-1) followed by becoming solventogenic

- During solventogenic stages fluctuations in solvent concentrations were less

Glass beads

C. acetobutylicum culture

- Biomass accumulation takes much longer than bone char

- During initial stages (2–4 days) higher amount of polysaccharide production does not occur

- Cells do not stick to the support as firmly as onto bonechar

- Reactor produces <20% solvents as compared to bonechar adsorbed cells

- Reactors are not stable as solvent concentration fluctuates

- Cells can easily be washed off

Glass wool, Polypropylene tow, and stainless steel wire balls

C. acetobutylicum culture

- <20% biomass accumulated than in bonechar packed reactor

- Cells do not stick to the support firmly and can be desorbed easily

- Reactors are not stable and poor solventogenesis occurred

Clay brick (Ref. 38)

C. beijerinckii culture

- Cells stick firmly as in case of bonechar and reactors were solventogenic

Qureshi et al. Microbial Cell Factories 2005 4:24   doi:10.1186/1475-2859-4-24

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