Microbial Biotechnology

Commercial Production of Microorganism

LECTURE 11:

Biotechnology; 3 Credit hours

Atta-ur-Rahman School of Applied Biosciences (ASAB)

National University of Sciences and Technology (NUST)

Commercial Production of Microorganism

Biochemist define fermentation as anaerobic process;• That generate energy by the breakdown of the

organic compound• The end product can be microbial metabolite;• Lactic acid• Enzyme• Alcohol, ethanol, butanol and acetone

Commercial Production of Microorganism

• Industrial users of fermentation have broadened the definition to include;

1. Any process that produce bacteria or fungi as the end product

2. Biotransformation; transformation by cells of a compound added to the fermentation medium of a commercially valuable compound

• In large scale fermentation metabolites, proteins, carbohydrates and lipids are provided to enable the propagation of microbial cell or biomass

Bioreactor (Fermenter)• Aerobic or anaerobic bacteria are cultured

under controlled conditions in large chamber called fermenter or bioreactor

Steps of Fermentation

1. Sterilization of fermenter and associated equipment

2. Preparation and sterilization of the culture medium

3. Preparation of the pure culture for inoculation of the medium culture in the fermenter vessel

4. Cell growth and synthesis of the desired product under a specific set of conditions

5. Product extraction and purification or cell collection

6. Disposal of expended medium and cell, and cleaning of the bioreactor and equipment

Steps of Fermentation

Industrial Fermenter

• Fermentation technology is linked with the improved productive performance of microorganism by optimizing their growth conditions

• Most of the organism used in fermentation are aerobic; because aerobic metabolism is more efficient than anaerobic metabolism

• Beside requiring oxygen for rapid growth they need a consistent pH in growth medium, temperature conditions, a supply of nutrients and an antifoaming agent

Fermenter types• Stirred Tank Reactor– It relies on an agitator to circulate oxygen

• Airlift Fermenter– It supplies oxygen to the culture through an intake

valve in the bottom of the culture vessel

Continuous Fermenter• In continuous fermentation, nutrients are fed

into the fermenter while an equal volume of the products, cells and medium is collected

• It allow continuous culture growth to be maintained for long time

• This method is more suitable for obtaining compound that are produced proportionally to cell growth, such as primary metabolite i.e. vitamin, enzyme etc.

• It also suitable for waste water treatment or degrading organic compound

Continuous Fermenter

Batch Culturing or Fermentation

• Cells, products and medium are collected after the fermentation process has been terminated

• This method is preferred when synthesis of the products does not depend on the amount of cell biomass

Solid Substrate Fermentation

• Microorganism are grown on solid substrate that are not submerged in liquid media

• Oxygen is more readily available to the cell as they are direct in contact with it

• Product recovery is much easy in this procedure

corn-soybean meal based dietsBy Solid substrate fermenter for animals

Single Cell Protein

• A monoculture of algal, bacterial or fungal cell has a protein content that is 70-80% of its dry weight

• When such culture are grown in large volume for use as human or live stock feed supplements, it is called single cell protein

• SCP is rich in nutrients as minerals, vitamins, carbohydrates, lipids as well essential amino acids like lysine and methionine which are absent in plant protein

• SCP is produced by using inexpensive substrate to supply nitrogen and carbon

• For example carbohydrate containing raw materials, waste from cheese production and pulp mils

• SCP may contain toxic compound• Nucleic acid, hepatoxins, heavy metals

absorbed from the substrate• Effective research is needed to remove these

toxic compound from SCP

Single Cell Protein