Biotechnology - Lecture Notes

Introduction to Biotechnology

  • Presentation by Dr. Julianne Megaw, BIO1301 World of Microorganisms.
  • Topics Covered:
    • Definition and scope of biotechnology.
    • Focus on microbial biotechnology and its applications.
    • Industrial fermentation processes.
    • Comparison of batch culture vs. continuous culture.

What is Biotechnology?

  • Definition: Biotechnology is the exploitation of biological processes for industrial and other purposes, particularly involving genetic manipulation of microorganisms for producing antibiotics, hormones, etc.
  • Microbial Biotechnology: Using microorganisms to our advantage.

History of Biotechnology

  • Early biotechnology dates back thousands of years:
    • Ancient Egyptians brewed beer around 6000 B.C.
    • Evidence from 7000 B.C. of fermentation processes in Neolithic China involving honey and rice.

Microbial Biotechnology

  • Utilization of microorganisms for:
    • Production: e.g., antibiotics, enzymes, alcohols.
    • Processes: e.g., bioremediation.
  • Functions on a large scale using culture methods.

Benefits of Using Microorganisms

  • Key factors contributing to their extensive industrial use:
    • Diversity of metabolism allows for broad applications.
    • Economic growth: Small size enables mass culturing cheaply.
    • Fast growth rate leads to quicker yields.
    • Genetic modification capabilities allow for increased production efficiency.
    • Tolerance to extreme conditions: e.g. extremophiles working in harsh environments.

Requirements for Industrial Microorganisms

  • Ideal characteristics include:
    • High yield of desired product.
    • Rapid growth on inexpensive media.
    • Amenable to genetic manipulation.
    • Preferably nonpathogenic to ensure safety.

Major Microbial Products and Processes

  • Substances and Microorganisms:
    • Ethanol production:
    • From glucose: extSaccharomycescerevisiaeext{Saccharomyces cerevisiae}.
    • From lactose: extKluyveromycesfragilisext{Kluyveromyces fragilis}.
    • Industrial enzymes: include extAspergillusext{Aspergillus} and extBacillusext{Bacillus}.
    • Antibiotics: extPenicillium,Streptomycesext{Penicillium, Streptomyces}.
    • Biofuels: includes extEscherichiacoliext{Escherichia coli}.

Types of Microbial Products

  • Primary Metabolites:
    • Produced during normal growth; examples include amino acids, nucleotides, ethanol.
  • Secondary Metabolites:
    • Accumulate after growth phase under nutrient limitation; example: penicillin.

Fermenters (Bioreactors)

  • Defined as enclosed, sterilized vessels for microorganism growth:
    • Conditions monitored for optimal growth.
    • Features include:
    • Probes for monitoring.
    • Nutrient inlets and waste outlets.
    • Temperature control systems.
  • Types of data for optimal monitoring include pH and temperature.

Cultivation Methods in Fermenters

  • Batch Culture:

    • Close system where nothing is added/removed except gas.
    • Nutrients exhausted over time, requiring a full clean to restart.
    • Advantages: Low contamination risk, flexibility in products.
    • Disadvantages: Idle time lowers productivity, higher labour costs.

  • Continuous Culture:

    • Open system allowing for continuous addition of nutrients and removal of products.
    • Optimal for maximizing yields at certain growth stages.
    • Advantages: Higher productivity, automation makes it cost-effective.
    • Disadvantages: Increased contamination risk, potential cell growth issues.

Use of Genetically Modified Organisms (GMO)

  • Using GMOs can allow:
    • Faster-growing organisms.
    • Simplified nutrient needs.
    • Enhanced product yields through overexpression of desired genes.

Learning Outcomes

  • Define biotechnology and its applications.
  • Recognize microorganism benefits in biotechnology.
  • Understand differences between primary and secondary metabolites.
  • Compare batch and continuous cultures and their practical implications in biotechnology.