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Microbial Biotechnology Chapter 5
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Microbial Biotechnology

Feb 12, 2016

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Jay Al Badri

Microbial Biotechnology. Chapter 5. The Structure of Microbes. Prokaryotes Archaebacteria Includes halophiles, thermophiles, “extremophiles” Eubacteria On skin, soil, water, can be pathogenic. The Structure of Microbes. Characteristics of Prokaryotes Generally smaller than Eukaryotes - PowerPoint PPT Presentation
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Page 1: Microbial Biotechnology

Microbial Biotechnology

Chapter 5

Page 2: Microbial Biotechnology

The Structure of MicrobesProkaryotes • Archaebacteria

• Includes halophiles, thermophiles, “extremophiles”• Eubacteria

• On skin, soil, water, can be pathogenic

Page 3: Microbial Biotechnology

The Structure of MicrobesCharacteristics of Prokaryotes• Generally smaller than Eukaryotes• No nucleus• Cell wall composed of peptidoglycan • Conjugation (transfer of DNA by cytoplasmic

bridge)• Transduction (DNA is packaged in a virus and

infects recipient bacterial cells)• 20 minute growth rate (binary fission

Page 4: Microbial Biotechnology

Yeast are Important Too!Single celled eukaryote Kingdom: FungiOver 1.5 million speciesSource of antibiotics, blood cholesterol

lowering drugsAble to do post translational modificationsGrow anaerobic or aerobicExamples: Pichia pastoris (grows to a

higher density than most laboratory strains), has a no. of strong promoters, can be used in batch processes

Page 5: Microbial Biotechnology

Microorganisms as Tools

Microbial Enzymes• Taq (DNA polymerase), cellulases, proteases,

amylases

Page 6: Microbial Biotechnology

Bacterial Transformation• The ability of bacteria

to take in DNA from their surrounding environment

• Bacteria must be made competent to take up DNA

Microorganisms as Tools

Page 7: Microbial Biotechnology

Cloning and Expression Techniques• Fusion Proteins

Microorganisms as Tools

Page 8: Microbial Biotechnology

Microbial Proteins as Reporters• Examples: the lux gene which

produces luciferase • Used to develop a fluorescent

bioassay to test for TB

Microorganisms as Tools

Page 9: Microbial Biotechnology

Yeast Two-Hybrid System• Used to study protein interactions

Microorganisms as Tools

Page 10: Microbial Biotechnology

Using Microbes for a Variety of Everyday Applications

Food Products• Rennin used to make curds (solid) and whey in

production of cheese• Recombinant rennin is known as chymosin

(first recombinant food product approved by FDA)

Page 11: Microbial Biotechnology

Using Microbes for a Variety of Everyday Applications

Food Products• Energy production in

bacteria• Aerobic or anaerobic

Page 12: Microbial Biotechnology

Using Microbes for a Variety of Everyday Applications

Food Products• Fermentation (anaerobic respiration)• Lactic acid

fermentation• Used to make

cheese, yogurt, etc.

• Ethanol fermentation• Used to make beer

and wine

Page 13: Microbial Biotechnology

Therapeutic proteins• Recombinant insulin in bacteria

Using Microbes for a Variety of Everyday Applications

Page 14: Microbial Biotechnology

Field Applications of Recombinant Microorganisms• Ice-minus bacteria (remove ice protein

producing genes from P. syringae)• P. fluorescens containing the gene that codes

for the bacterial toxin from Bacillus thuringiensis (kills insects) Bt toxin!

Using Microbes for a Variety of Everyday Applications

Page 15: Microbial Biotechnology

Using Microbes Against Other Microbes• Antibiotics• Act in a few key ways

• Prevent replication• Kill directly• Damage cell wall or prevent its synthesis

Using Microbes for a Variety of Everyday Applications

Page 16: Microbial Biotechnology

VaccinesFirst was a vaccine against smallpox

(cowpox provides immunity)• DPT-diphtheria, pertussis, and tetanus• MMR –measles, mumps, and rubella• OPV- oral polio vaccine (Sabin)

Page 17: Microbial Biotechnology

A Primer on Antibodies• Antigen- foreign substances that stimulate an

immune response• Types of leukocytes or white blood cells

• B-lymphocytes: antibody-mediated immunity• T-lymphocytes: cellular immunity• Macrophages: “cell eating” (phagocytosis)

Vaccines

Page 18: Microbial Biotechnology

Heavy chain

Light chain

IgA – first line of defense

IgG and IgM – activates macrophages

Vaccines

Antigens stimulate antibody production in the immune system

Page 19: Microbial Biotechnology

Vaccines

Mechanism of Antibody Action

Page 20: Microbial Biotechnology

How are vaccines made?• They can be part of a pathogen (e.g. a toxin)

or whole organism that is dead or alive but attenuated (doesn’t cause disease)• Subunit (toxin) or another part of the pathogen• Attenuated (doesn’t cause disease)• Inactivated (killed)

What about flu vaccines (why do we have to get a shot every year?)

Vaccines

Page 21: Microbial Biotechnology

Bacterial and Viral Targets for Vaccines

Immune Therapy• Used to enhance natural

immune responses• Ex: Interferon is a protein

that triggers production of protective proteins (or antibodies) that inhibit viral replication.

Page 22: Microbial Biotechnology

Bacterial and Viral Targets for Vaccines

HIV

Page 23: Microbial Biotechnology

Microbial Genomes Microbial Genome Program

(MGP) –the goal is to sequence the entire genomes of microorganisms that have potential applications in environmental biology, research, industry, and health

Sequencing Strategies

Page 24: Microbial Biotechnology

Microbial GenomesWhy study viral genomes?• Decipher genes and their products so that agents

that block attachment, block replication can be made

Page 25: Microbial Biotechnology

Microbial Diagnostics Using Molecular Techniques to Identify Bacteria

• RFLP• PCR and Real time PCR• Sequencing

Page 26: Microbial Biotechnology

Microbial DiagnosticsMicroarrays for

tracking contagious disease• PulseNet used to

identify outbreaks

Page 27: Microbial Biotechnology

Combating Bioterrorism• The use of biological materials as weapons to

harm humans or animals and plants we depend on for food

• Examples in History• Throwing plague infected dead bodies over the walls of

their enemies

Microbial Diagnostics

Page 28: Microbial Biotechnology

Using Biotech Against Bioweapons• Postal service x-raying packages• Antibody tests in the field• PCR tests in the field• Protein Microarrays for detecting bioweapon

pathogens

Microbial Diagnostics