Suffolk Community CollegeEastern campus

General Microbiology- BIO244CRN #  91240 Section # 401

Fall 2017Instructor: Adriana Pinkas, PhD

Web site: http:/www2.sunysuffolk.edu/pinkasaEmail: pinkasa@sunysuffolk.edu

Chapter 1

The Microbial World And You

What is a microorganism?(micro-organism)

•Organism that is too small to be seen with the naked eye.–micro - is a prefix in the International System of Units and other

systems of units denoting a factor of 10−6 (one millionth) meter. Symbol- µ

–organism – a form of life• Life is a condition that distinguishes organisms from inorganic objects• Life fundamental feature:

– growth– reproduction – adaptation to the environment through changes originating internally

Microbiology is the study of microscopic organisms

Based on their similarity and difference all organisms are organized in The Three-Domain System.

Mitochondrion degeneratesOrigin of chloroplasts

Bacteria

Mitochondria

Cyanobacteria

Chloroplasts

Thermotoga

Gram-positivebacteria

Proteobacteria

Horizontal gene transferoccurred within thecommunity of early cells.

Nucleoplasm grows larger

Giardia

Euglenozoa

Diatoms

Dinoflagellates

Ciliates

AnimalsFungi

Amebae

Slime molds

Plants

Greenalgae

Eukarya

Extremehalophiles

Methanogens

Hyperthermophiles

Origin of mitochondria

Achaea

Ancestors of bacteria were the first life on Earth.

Classification of Microorganisms

• Three domains• Bacteria•Archaea• Eukarya

• Protista

• Protozoa•Algae

• Fungi

•Viruses

}Prokaryotic

}Eukaryotic

Acellular

Bacteria• Prokaryotic -they have no nucleus•Unicellular organisms. • Cell wall - peptidoglycan •Divide by binary fission• For energy, use:• organic chemicals • inorganic chemicals• or photosynthesis

• Free living• 3 common shapes:• Bacillus• Coccus• Spiral

Figure 1.1a

Archaea• Prokaryotic•Unicellular organisms.• Cell wall - Lack peptidoglycan• (pseudomurein)

•Divide by binary fission• For energy, use:• Organic• Inorganic• photosynthesis

• Free living• Live in extreme environments•Methanogens• Extreme halophiles• Extreme thermophiles

Figure 4.5b

Eukarya - Fungi

• Fungi (mushrooms, molds, and yeasts) have a true nucleus and they are eukaryotic cells•Yeasts are unicellular•Molds and mushrooms are multicellular • consisting of masses of mycelia, which are

composed of filaments called hyphae

• Cell walls - Chitin •Reproduction – asexual and sexual

(mitosis or meiosis)• For energy, use organic chemicals • obtain nutrition by absorption

• Free living

Figure 1.1b

Eukarya – Protista - Protozoa

• Protozoa are eukaryotes.•Unicellular •Have no cell wall • pellicle - a thin layer supporting the cell

membrane in various protozoa •Reproduction – asexual and sexual

(mitosis or meiosis)• Free living or parasites• For energy, use organic chemicals• Protozoa obtain nutrition by absorption or

ingestion through specialized structures.

Figure 1.1c

Eukarya – Protista - Algae

• Eukaryotes•Unicellular, filamentous, or

multicellular (thallic)• Cell walls - Cellulose •Reproduction – asexual and sexual

(mitosis or meiosis)• Free living•Use photosynthesis for energy• Produce molecular oxygen and organic

compounds

Figure 1.1d

Viruses

•Acellular• Consist of DNA or RNA core• Core is surrounded by a protein coat• Coat may be enclosed in a lipid

envelope•Reproduction – use host resources•Viruses are replicated only when

they are in a living host cell•Obligate cellular parasite

Figure 1.1e

Naming and Classifying Microorganisms

•Binomial nomenclature• Carlous Linnaeus 1735 established the

system of naming specific species.

•Each organism has two names: • The genus (capitalized )• Specific epithet (lower case)

•Are “Latinized” and used worldwide.•Names are written in italics or underlined.

Scientific names• Staphylococcus aureus– Genus - Staphylococcus - describes the clustered arrangement of the cells (staphylo-)– Specific epithet – aureus - the golden color of the colonies.

• Escherichia coli– Genus – Escherihia -Honors the discoverer, Theodor Eshcerich– Specific epithet – coli - describes the bacterium’s habitat, the large intestine or colon.

•After the first use, scientific names may be abbreviated with the first letter of the genus and the specific epithet:

Staphylococcus aureus and Esherichia coli are found in the human body. S. aureus is on skin and E. coli, in the large intestine.

Where do microorganisms live ?

•Microorganisms are found in almost every habitat present in nature • Soil • Hot springs • Oceans • High in the atmosphere• Deep inside rocks within the Earth's crust• On and in other organisms bodies

• Present all types of metabolism (use different sources of carbon and energy)• Reproduce rapidly • They are very adaptive

Why can they live in every environment ?

In 1665, Robert Hooke - introduced the term cells

- observed that cork was composed of “little boxes”

1673-1723, Anton van Leeuwenhoek - first described live microorganisms - observed teeth scrapings, rain water, and peppercorn infusions - ”animalcules”

A Brief History of Microbiology

A Brief History of Microbiology• The Debate Over Spontaneous Generation• Spontaneous Generation theory:•

Living organisms arise from nonliving matter, a “vital force’ forms life

• Biogenesis hypothesis

Living organisms arise from preexisting life

–In 1858, Rudolf Virchow challenged the spontaneous generation theory with the concept of biogenesis

Cell Theory

All living things are composed of cells and come from preexisting cells

Figure 1.3 Disproving the Theory of Spontaneous Generation.

Pasteur first pouredbeef broth into along-necked flask.

Microorganisms werepresent in the broth.

Next he heated the neckof the flask and bent itinto an S-shape; then heboiled the broth forseveral minutes.

Microorganisms were not present in the broth after boiling.

Microorganisms did notappear in the cooled solution,even after long periods.

Bend prevented microbesfrom entering the flask.

Microorganisms werenot present even afterlong periods.

1861, L.Pasteur - Pasteur’s S-shaped flask kept microbes out but let air in.

1. Microorganism can be present in nonliving mater2. Microbial life can be destroyed by heat 3. That methods can be devised to block the access of airborne microorganisms to nutrient environment.

Louis Pasteur (1822-1895) 1. Disproving spontaneous generation • The air by itself does not create microbes

2. Father of aseptic technique • Techniques that prevent contamination by unwanted microorganisms• Modern aseptic techniques are among the first and most important things

a beginning microbiologist learns

3. Invent Fermentation and Pasteurization • Fermentation – some microorganisms (yeasts) are responsible for the

conversation of sugar to alcohol to make beer and wine.• Microbial growth is also responsible for spoilage of food.

• Bacteria that use alcohol and produce acetic acid spoil wine by turning it to vinegar (acetic acid).

• Pasteurization - application of a high heat for a short time– Demonstrated that the spoilage bacteria could be killed by heat that was not hot enough

to evaporate the alcohol in wine.

4. The relationship between microbes and disease • 1865 Pasteur believed that a silkworm disease was caused by a protozoan.

• 1860s: Joseph Lister - ‘Father of Antiseptic Surgery’

• Used a chemical disinfectant (carbolic acid ) to prevent surgical wound infections (1876)

•Development of vaccines• 1796: Edward Jenner inoculated a person with cowpox virus. The person was

then protected from smallpox.• Called vaccination from vacca for cow• 1880: L.Pasteur select avirulent strains used for vaccine.

• The role immunity in cure of disease• The protection from disease provide by vaccination is called immunity

The Germ Theory of Disease - Robert Koch •Robert Koch isolated:• Bacillus anthracis (1877) • Tuberculosis bacillus (1882) • Vibrio cholerae (1883)

• Provided proof that a specific microbe

causes a specific disease. • 1883: Koch’s postulates which say that

to establish that an organism is the cause

of a disease, it must be: • found in all cases of the disease examined • prepared and maintained in a pure culture • capable of producing the original infection, even after several generations in culture • be retrievable from an inoculated animal and cultured again.

The Birth of Modern Chemotherapy•Chemotherapy - treatment of disease with chemical substances

• Quinine from tree bark was long used to treat malaria.• 1910: Paul Ehrlich developed a synthetic arsenic drug, salvarsan, to

treat syphilis.• 1930s: Sulfonamides were synthesized.• 1928: Alexander Fleming discovered the first antibiotic.

• He observed that Penicillium fungus made an antibiotic, penicillin, that killed S. aureus.• 1940s: Penicillin was tested clinically and mass produced

Modern Developments in Microbiology

•Microbial genetic study of how microbes inherit traits• genes encode a cell’s enzymes (1942)• DNA was the hereditary material (1944).• the role of mRNA in protein synthesis (1961).

•Molecular biology is the study of how DNA directs protein synthesis

•Genomics: the study of an organism’s genes; has provided new tools for classifying microorganisms

•Recombinant DNA: DNA made from two different sources

Modern Developments in Microbiology

• Bacteriology is the study of bacteria and archaea.

•Mycology is the study of fungi.

• Parasitology is the study of protozoa and parasitic worms.

• Phycology is study of algae

•Virology is the study of viruses.

• Immunology is the study of immunity.

Microbes and Human WelfareAre they good or bad?

1. Microorganisms are important in the maintenance of an ecological balance on Earth. • Microbial Ecology• Bacteria recycle carbon, nitrogen, sulfur, and phosphorus that can be used by

plants and animals.• Bacteria degrade organic matter in sewage.• Bacteria degrade or detoxify pollutants such as oil and mercury

• Bioremediation• The use of bacteria, fungi, green plants or their enzymes to remove or reduce human-made pollution. • Main principal – to enhance activity of the naturally occurring organisms that can perform bioremediation

• Insect pest control - GMO

Microbes and Human Welfare2. Some microorganisms are used to produce foods and chemicals.

•Biotechnology• the use of microbes to produce foods and chemicals, is centuries old.

•Genetic engineering - use of recombinant DNA technique for modern biotechnology. • Bacteria and fungi can produce a variety of proteinsincluding vaccines, human hormones and enzymes • Genetically modified bacteria are used to protectcrops from insects and freezing• Missing or defective genes in human cells can be replaced in gene therapy.

Microbes and Human Welfare

3. Some microorganisms normally present (live) in and on the humans and other animals and are needed to maintain good health -Normal Microbiota (microflora)

Microbiome - the combined genetic material of the microorganisms in a particular environment ( human body)

• Gut microbiome – “forgotten organ”• Produce hydrolytic enzymes - help our digestive

system

• Synthesize vitamins – K, B2, B12 and folic acid

• Skin and gut microbiome• Stabilize epithelial homeostasis and barrier function

• Modulate our innate and adaptive immunity

• Prevent growth of pathogens

• Production of antimicrobial substances

• Compete for the nutrients

Microbes and Human Welfare

• Pathogen – "that which produces suffering.“- causes infection disease

• Infection disease – presence of particular microorganism in part of the body where is not usually found.

•Resistance is the ability of the body to ward off disease. • When a pathogen overcomes the host’s resistance, disease results.

• Emerging Infectious Diseases (EID): New diseases and diseases increasing in incidence

Some microorganisms cause disease

How microorganisms are connected to our lives?• Primary producers in the ecosystems - food chain, oxygen•Decompose organic waste• Produce fermented foods such as vinegar, cheese, and bread• Produce industrial chemicals such as ethanol and acetone•Used in manufacturing to produce products for industry (e.g.,

cellulase) and disease treatment (e.g., insulin)• Some are pathogenic (disease-causing)

• Led to aseptic techniques to prevent contamination in medicine and in microbiology laboratories•Allows humans to prevent food spoilage• Prevent disease occurrence and treat diseases•May be will help us to save the planet

How the knowledge of microorganisms helps us?

Learning objectives

• Recognize the system of scientific nomenclature that uses two names: a genus and specific epithet. • Differentiate among the major characteristics of each group of

microorganisms. • List the three domains. • Compare spontaneous generation and biogenesis. • Identify the contributions to microbiology made by Hooke, van

Leeuwenhoek, Virchow, Pasteur, Lister, Koch, Jenner, Ehrlich, and Fleming. • Define bacteriology, mycology, parasitology, immunology, and virology. • List beneficial activities of microorganisms. • List harmful activities of microbes • Define normal microbiota and resistance.