Question

What are the advantages of bioreactor which uses continuous culture system rather than batch culture?

Answer 1

• Continuous reactions offer increased opportunities for system investigation and analysis. As the variables remain unchanged, a benchmark can be determined for the process results, and then the effects of even minor changes to physical or chemical variables can be evaluated. By changing the growth-limiting nutrient, changes in cell composition and metabolic activity

can be tracked. The constancy of the continuous process also provides a more accurate picture of kinetic constants, maintenance energy, and true growth yields.

• Continuous culture provides a higher degree of control than a batch culture. Growth rates can be regulated and maintained for extended periods. By varying the dilution rate, biomass concentration can be controlled. Secondary metabolite production can be sustained simultaneously along with growth. In a steady state continuous culture, mixed cultures can be maintained using chemostat cultures – unlike in a batch process where one organism usually outgrows another.

• Bioreactors operated as chemostats can be used to enhance selectivity for thermophiles, osmotolerant strains or mutant organisms with high growth rates. Also, the medium composition can be optimized for biomass and product formation using a pulse- and shift- method that injects nutrients directly into the chemostat. As changes are observed, the nutrient is added to the medium supply reservoir and a new steady state is established.
• Because of the steady state of continuous culture, the results are not only more reliable but also more consistent leading to a better quality product.
  

• It also results in higher productivity per unit volume, as time-consuming tasks, such as cleaning and sterilization are unnecessary.

• The ability to automate the process makes it more cost-efficient and less sensitive to the impact of human error.