Beer, Drugs and Dairylea Slices

Beer Production Process

  1. Malted Barley: Partially germinated barley grains.

  2. Heating: Expose to 65Ā°C to kill harmful microbes.

  3. Add Yeast: Yeast ferments sugar from barley.

  4. Fermentation: Produces alcohol as a by-product.

  5. Post-Fermentation Steps:

    • Remove yeast

    • Filter

    • Pasteurize and bottle the beer

Cheese Production

  • Overview:

    • Made from pasteurized milk by separating curds (solids) and whey (liquid).

    • Rennet Addition:

      • Mainly chymosin (an aspartic acid protease).

      • Originally derived from calf stomachs, now often produced by microbes.

    • Microbial Influence:

      • The flavor and texture of cheese depend on microbes during maturation.

      • Example: Penicillium roqueforti used for Roquefort and Stilton cheeses.

Vinegar Production

  • Overview

    • Initially accidental from wine makers.

    • Produced by wine exposure to air, leading to contamination by Acetobacter, oxidizing alcohol to acetic acid.

  • Modern Method:

    • Use of yeast for ethanol production followed by acetic acid conversion using Acetobacter.

Pruteen Production

  • History:

    • Developed in the 1970s at ICI Pruteen bioreactor, Billingham, UK.

    • Composition: Made from Methylophilus methylotrophus bacteria, using methanol with a protein content of 72%.

  • Current Use: The plant now produces Quorn.

Microbes in Environmental Remediation

  • Microbial Role:

    • Microbes effectively break down organic materials in sewage.

    • If sewage is released into water bodies, it can trigger rapid microbial growth, leading to oxygen depletion and harming aquatic life.

  • Activated Sludge Process:

    • Involves autotrophs and heterotrophs to break down waste.

    • Autotrophs: Require CO2 and inorganic compounds for energy.

    • Heterotrophs: Need organic nutrient to make organic compound, use organic carbon for energy.

cleaning after us

Bioremediation Techniques

  • Use of microbes to break down dangerous chemicals

  • Converts oil to less harmful forms.

Controversy Around Bioremediation

  • Deepwater Horizon Spill (2010):

    • Alcanivorax borkumensis was employed for clean-up.

    • Gulf residents reported rashes, potentially linked to the bacterium's cell wall.

Bacteria and Biodegradable Plastics

  • Plastic Production:

  • Can produce useful compounds already encoded in bacterial genome

  • Can also be genetically manipulated to make them produce useful non-native (exogenous) molecules

  • steps:

  • Copy gene made by PCR.

  • Insert gene of interest into an expression vector.

  • Return vector to the organism for growth and protein production.

Pharmaceutical Applications of Microbial Factories

  • Vaccines: Protective antigen genes derived from pathogen genome sequencing.

  • Vitamins: Production of essential nutrients like B12 by microbes.

  • Antibiotics: E.g., streptomycin from Streptomyces griceus.

Importance of Protein Drugs

  • Protein drugs are safer since they are not derived from human blood (reduce risk of infections).

  • Examples:

    • Insulin for diabetes

    • Factor VIII for hemophilia

    • Erythropoietin for anemia

    • Follicle Stimulating Hormone for fertility

    • Growth Hormones for deficiencies

Human Gene Therapy

  • Altering defective genes using vectors for targeted delivery into cells.

  • Potential for treating disorders traceable to single defective gene

  • Vectors used for delivery of genes into specific cell types (bone marrow)

Gene Therapy Procedure

  1. Insert RNA version of normal gene into retrovirus

  2. Let retrovirus infect bone marrow cells that have been removed from the patient and cultured

  3. Viral DNA carrying the normal gene inserts into chromosome

  4. Return engineered cells to the patient.

Challenges in Gene Therapy

  • DNA presence is short lived - patients need multiple transfections

  • Immune reactions limiting transfections - however potentially fatal

Risks and Future of Gene Therapy

  • Possibility that viral vector may recover ability to cause disease

  • Vector may load gene near to oncogene, triggering cancer ā€¢

  • Easier for single-gene defects, e.g. cystic fibrosis

Lentivirus as a Gene Delivery Vector

  • Lifecycle Steps:

    1. Binding and entry

    2. Uncoating

    3. Reverse transcription to DNA

    4. Proviral integration into host genome