Microbial Biotechnology

BIOL410

Course outline• Introduction: microbial biotechnology scope and history• Microbial Diversity• Microbial metabolism• Fermentation • Microbial Biotechnology in Agriculture and Aquaculture• Overview session• Mid Term Exam• Production of Proteins in Bacteria and Yeast• Recombinant DNA technology• Medical applications• Food technology• Bioremediation• Environmental Applications of Microorganisms• Overview session• Final exam

Industrial Microbiology

• Humans were using microbes even before they knew about their existence

• As the knowledge of microbes grew , humans improved & expanded their uses

• Now managing these microbe has become a science

Uses of Microbes

• Antibiotics• Vitamins• Food supplements• Industrial chemicals• Recombinant DNA technology

Microbes Are Everywhere!

• In the soil

Microbes Are Everywhere!

• In thermal areas

Microbes Are Everywhere!

• In ice

Microbes Are Everywhere!

• In salt

Microbes Are Everywhere!

• In water, viruses outnumber bacteria by 2-10:1

Microbes Are Everywhere!

• In the deeps

Microbes Live Together

• In biofilms in pipes

Microbes Live Together

• On your teeth

And with other organisms

• With plant roots

And with other organisms

• In coral

And with other organisms

• In clams

And with other organisms

• In lichens

And with other organisms

• With cows and termites

And with other organisms

• With fish

We Use Existing Microbes

• To make foods

We Use Existing Microbes

• To make alcohol

We Use Existing Microbes

• To clean up oil spills

We Use Existing Microbes

• To turn trash into soil

We Use Existing Microbes• To leach ores

We Use Existing Microbes

• To make medical products

Microbiotechnology

1. Traditional uses make & preserve human & animal food

2. As chemical factoriesmake chemicals & drugs

3. Genetically engineered microbes

Traditional usesa. Lactic acid bacteria

– Ferment sugars, – their metabolic products have a

pleasant taste– Used to make dairy products, cheese,

sauerkraut, green olives– With exception of some streptococci

these organisms are harmless to humans

Traditional usesb. Yeasts (Saccharomyces

cerevisiae)– Are as important as lactic acid

bacteria– Ferment sugars & produce ethanol &

CO2– Used in the wine industry– Bread making– To make vinegar 2 step process-

Yeasts ferment sugar to ethanol, then Acetobacter converts that to acetic acid

Mixed cultures

• Cultures of bacteria & fungi• Used to make fermented

foods kefir (laban), soy sauce, miso

Microbial Insecticides• Unlike chemical insecticides these are

ecologically safe• Species of Bacillus are insect pathogens

– B. thuringiensis endospores lethal to insects ( marketed as Bt)

– B. popilliae controls japanese beetles (marketed as Bp)

– Protozoa Nosema locustae bait for grasshoppers & locusts

2 Chemical FactoriesDue to their rapid rate of growth and

metabolism microbes are use to manufacture many commercial products

Can be done:AnaerobicallyAerobically

Anaerobic Fermentations

Most common substrate used is blackstrap molasses

• Ethanol• Acetone• Butanol

Aerobic ProcessesSterilized air must be supplied to prevent

contamination of cultures• Antibiotics• Amino acids used to enhance flavor of

foods• Enzymes wide variety of uses

Genetically Engineered Microbes

• Medical Uses• Agricultural Uses

Medical UsesGenetically engineered microbes use for:Hormones

Human growth hormoneInsulinTissue plasminogen activator binds to & dissolves clots

Vitamins

Agricultural Uses• Bt toxin• Ice minus gene• Better silage makers

Microorganisms and Agriculture

• Ice-nucleating bacteria story• Plant frost damage is caused by the presence

of ice-nucleating bacteria (Pseudomonas, Erwinia, Xanthomonas) on plants

• The ice+ gene on the bacterial chromosome encodes an ice-nucleating protein which allows for ice crystal formation at 0 to 2°C

• When the ice gene is deleted from the bacteria, ice crystal formation (frost damage) does not occur until -6 to -8°C

We Modify Microbes• To protect plants from pests

We Modify Microbes• To clean up toxic waste = bioremediation

We Modify Microbes• Recombinant DNA Technology:

– Insertion or modification of genes to produce desired proteins

We Modify Microbes• To make medicines

Herceptin• Trastuzumab (Herceptin) is a monoclonal antibody that interferes with

the HER2/neu receptor.

• The HER receptors are proteins that are embedded in the cell membrane and communicate molecular signals from outside the cell to inside the cell, and turn genes on and off. The HER proteins regulate cell growth, survival, adhesion, migration, and differentiation—functions that are amplified or weakened in cancer cells. In some cancers, notably some breast cancers, the HER2 receptor is defective and stuck in the "on" position, and causes breast cells to reproduce uncontrollably, causing breast cancer.

• Antibodies are molecules from the immune system that bind selectively to different proteins. Herceptin is an antibody that binds selectively to the HER2 protein. When it binds to defective HER2 proteins, the HER2 protein no longer causes cells in the breast to reproduce uncontrollably. This increases the survival of people with cancer. However, cancers usually develop resistance to herceptin.

Herceptin• Trastuzumab (perceptin) was originally

developed in mice, as a mouse antibody. Because humans have immune reactions to mouse proteins, it was later developed into a human (humanized) antibody. Because the antibodies were produced from one cell that was grown into a clone of identical cells, it is called a monoclonal antibody.

• Cost of treatment: 100 000 $ per year.

Structure of Herceptin

Acrylamide production Biotransformation

• Biotransformation:• Moderate conditions• Yield: almost 100%• No need to remove copper • Enzymatic process being

carried out below 10 C under• mild reaction conditions and

requiring no special energy source

• The immobilized cells are used repeatedly and a very

• pure product is obtained.• The first successful example of

using biotransformation in production of commodity chemicals

Acrylamide is one of the most important commodity chemicals. Its global consumptionis about 200,000 tonnes per year.

It is used in the production of variouspolymers for use as flocculants, additives or for petroleum recovery.

Immobilization (cell, enzyme)

• “Immobilized” means unable to move or stationary – an microorganism (or enzyme) that is physically attached to a solid support over which a substrate is passed and convert to product.

SummaryMicrobial Application

Problems with Biotechnology

• Transfer of genes found in transgenic organisms to natural populations.– Terminator genes have been used to

minimize this risk

Problems with Biotechnology

• Unexpected impacts of genetically modified organisms and biotechnology processes on other organisms and the environment

Problems with Biotechnology

• Expense of the utilization (research) of many biotechnology techniques

What Are Bioethics?• Ethics- knowing right from wrong,

and then doing the right idea• Bio- living organisms• Bioethics- knowing right from

wrong with living organisms, and then doing the right idea

• http://www.oelwein.k12.ia.us/hs/Ag.Home/biotechethics.htm