Microbiology Applications in Environment, Industry, and Public Health

Microorganisms in Industry, Food Production, and the Environment

• General Applications of Microorganisms:     * Microorganisms are essential in various industries and daily life processes, specifically in:         * Food production: used to create bread, beer, wine, yogurts, and cheeses.         * Biodegradation: the process of breaking down environmental pollutants.     * The Problem of Plastics:         * Plastics are accumulating in the environment because they are significantly difficult to degrade naturally.         * As they break down, they turn into small microparticles of plastic, which are now recognized as a potential health hazard and are ubiquitous in the environment.

Laboratory Application: Researching Plastic-Degrading Microbes

• Research Objective: To find and identify microorganisms capable of assisting in the degradation of plastics to address environmental accumulation.
• Methodology for Lab Isolation:     * Sample Collection: Students are instructed to collect a soil sample in provided plastic bags and bring it to the laboratory.     * Isolation Strategy: The lab will utilize specific growth media that "demands" the microorganisms be able to degrade plastic. This means the microbes will not grow in the laboratory environment unless they possess the metabolic ability to use plastic for growth.     * Characterization: Once isolated, students will measure the efficiency with which these microbes degrade the plastic.     * Identification: By the end of the course, students will identify the specific microorganism and learn general identification techniques used in clinical settings.
• Safety Note: The class focuses on non-clinical microbes (less dangerous) to ensure student safety while teaching the fundamentals of identification.

Bioremediation and Industrial Products of Bacteria

• Bioremediation: This is the use of microorganisms to hasten the decay of pollutants. A prime example is the selection of microorganisms to degrade oil spills.
• Antibiotics:     * Definition: An antibiotic is a substance produced by one microbe that inhibits the growth of another microbe.     * The Discovery of Penicillin: A scientist (Alexander Fleming) observed a fungal contaminant on a bacterial culture plate. He noticed that bacteria would not grow in the proximity of the fungus. This observation led to the isolation of penicillin.
• Biofuels and Dietary Supplements:     * Ethanol: Produced through the fermentation of raw materials like corn. Major factories are currently located in states such as Nebraska and Iowa.     * Amino Acids: Manufactured by microorganisms for use as dietary supplements.
• Natural Insecticides:     * Chemical insecticides are toxic to both the environment and humans.     * Microorganisms can be used as safer, natural insecticides. These microbes can be sprayed onto plants; they are harmless to humans but infect and kill target insects.

Biotechnology and Genetic Engineering

• Biotechnology: The use of microbiology or biochemical techniques to solve practical problems (e.g., synthetic biology).
• Genetic Engineering: The manipulation of microorganisms to produce specific metabolic byproducts or substances.
• Enzymes as Biological Catalysts:     * Definition: Biological catalysts that increase the rate of reaction without being consumed by the reaction.     * Utility: Enzymes are used as tools to cut DNA into pieces and splice them together.
• Process of Cloning and Recombinant DNA:     * Recombinant DNA: Formed by taking a specific piece of DNA, cutting it out using enzymes, and inserting it into a new DNA strand.     * Cloning: The recombinant DNA is placed into a bacterium, which then copies the DNA during reproduction. This process can be used to manufacture products of practical use, such as insulin.

The Importance of Basic Microbiology in Daily Life

• Public Health and Food Safety:     * Many people get sick during holidays like Thanksgiving due to a lack of basic microbiological knowledge regarding cross-contamination.     * Poultry Contamination: Approximately $98\%$ of poultry (chicken and turkey) is contaminated with Salmonella due to industrial processing methods.     * Industrial Processing Issues: Chickens are processed on long lines and go through "dip tanks" for washing. If a single chicken is contaminated with Salmonella, the entire tank becomes seeded with the bacteria, potentially exposing every bird that follows.
• Practical Safety Measures:     * Clean cutting boards thoroughly, especially those made of wood, as microbes are small enough to hide in tiny crevices.     * Avoid using the same surface for raw meat and foods eaten raw (like salad).     * In restaurants, food inspectors verify protocols, refrigerator temperatures, and storage habits. A common dangerous practice is storing raw chicken on a shelf above salad, allowing contaminated juices to drip down.

Historical and Modern Impact of Infectious Disease

• Historical Examples:     * Influenza: The pandemic of $1918-1919$ killed more Americans than all the wars combined (relative to that time period).     * The Plague (Black Death): Killed approximately $25$ million people in Europe (one-third of the population). It is transmitted via fleas on rodents.
• Modern Examples:     * COVID-19: A recent pandemic caused by a newly emerged global infection. More than $15$ million people worldwide have died from it. It has now moved into an "endemic" state but remains present.     * Pandemic Definition: A global spread of a new infection that has emerged.

Methods of Controlling Microorganisms

• Sanitation:     * Involves community arrangements for handling feces and providing clean water.     * Over $75\%$ of diseases in children under the age of $5$ globally are caused by contaminated water consumption. Chronic diarrhea from waterborne illness causes high death rates and can lead to permanent mental developmental delays (retardation).     * There is a global disparity in infrastructure; there are reportedly more cell phones in the world than toilets.
• Vaccination:     * Safe and effective vaccines have been proven to prevent disease with minimal side effects. Smallpox was totally eradicated through vaccination by the year $1977$.
• Antibiotics:     * Their use dramatically decreased infectious disease rates starting around $1940$.     * Antibiotic Resistance: Microbes can evolve to become drug-resistant, rendering antibiotics ineffective. The improper use of antibiotics has led to a global crisis where many microbes are no longer affected by standard drugs.

Evolution of Microbes and Emerging Diseases

• Microbial Evolution:     * Microbes change their genetics constantly to adapt to hosts (humans) and environment treatments (antibiotics).     * Antigenic Changes: Changes in genetic sequences lead to changes in surface antigens. This necessitates a new influenza vaccine every year.
• Epidemiology and Mitigation:     * Understanding disease transmission allows for control strategies.     * Example: In Colorado, plague is found in prairie dogs. Mitigation involves dusting prairie dog towns with flea powder to kill the vectors, rather than the rodents themselves.
• Emerging Infectious Diseases (EID): Newly recognized diseases or those increasing in incidence within the last $5$ to $10$ years including:     * Monkeypox: Re-emerged after smallpox vaccinations ceased (smallpox vaccines provided cross-protection).     * Ebola Virus: New strains in Africa require new vaccines.     * Zika Virus, MERS (Middle East Respiratory Syndrome), and SARS: Emerging viral threats.     * Influenza Adaptation: New types are evolving to infect different mammals, such as bird flu infecting dairy cattle and workers.     * Toxigenic E. coli (O157:H7): Evolved from normal gut flora into a pathogen by picking up a toxin from Shigella. It can cause hemolytic uremia syndrome (kidney failure) in children under $5$.
• Microbes and Chronic Disease:     * Microbes are now linked to conditions previously thought to be non-infectious, such as:         * Stomach ulcers: caused by Helicobacter pylori (formerly attributed to stress).         * Cervical cancer: linked to Human Papillomavirus (HPV).         * Diabetes and autoimmune diseases: microbes may increase the risk or initiate the response.

Questions & Discussion

• Student Question regarding the Lab/Syllabus: There is confusion between the syllabus stating "up to one lab can be missed" and "missing four labs means failure."     * Response/Discussion: The student and instructor discussed potential makeup points and the personal nature of nursing/CNA work. The instructor mentioned that being a nurse requires empathy as people are not always at their best when sick.
• Study Resources Shared between Students:     * One student recommends an app called Knowt (spelled K-N-O-W-T) for summarizing lectures and creating active recall materials (reactive recall).
• Logistics: The instructor will provide a 15-minute break and begin covering Chapter 2, though much will be skipped as students should already know basic DNA structure from biology. Students who took biology more than $5$ years ago are encouraged to review independently.