Goals for this week

•become familiar with the processes and expectations for this class

•understand why microbiology is important

•cover some of the underlying themes of microbiology

•become adept at the use of the microscope

MICROBIOLOGYWhat is it?

The study of microbes

What are microbes?

Organisms that can’t be see with the naked eye………..

Like bacteria, viruses, fungi, protists, some algae, and some parasites (helminths)

In addition to the subdisciplines of microbiology (microbial genetics, microbial ecology, food microbiology, etc), microbiology also involves processes that include immuunology, epidemiology, bacterial physiology

Why is the study of microbiology important? •microbes make up 60% of the biomass on the earth

•microbes are responsible for recycling vital elements

•microbes clean up pollutants

•microbes are the mainstays of biotechnology

•microbes are responsible for many human and animal diseases

•many products in normal use are derived from microbes(can you think of one? http://www.bacteriamuseum.org/niches/foodsafety/goodfood.shtmlhttp://news.bbc.co.uk/1/hi/sci/tech/1630158.stmhttp://www.chm.bris.ac.uk/webprojects2002/thornton/antibiotics.htm)

•the study of microbes has let to major scientific discoveries that apply to human processes

•bacteria were here first (by about 2 billion years)

•bacteria are the first to colonize inhospitable environments and serve as the foundation for colonization by other organisms

•bacteria form many important symbiotic relationships

•bacteria can live where other organisms cannot liveand lots more!!!

Worldwide infections

Cell types of microorganisms:

prokaryotes – are smaller, less complex, contain no nucleus. These include bacteria

eukaryotes – are larger, more complex, contain nucleus and complex internal membrane-bound organelles. fungi, algae, small parasitic worms, most protists

viruses are in a class by themselves. Some say that they are not even living. They are considered to be obligate, intracellular parasites.

Diagram of General Cell Types

Changing unitsdo it any way that makes sense to you

if you are having trouble, consider going by increments of 1,000. If you are going from smaller size to larger size, divide. If you are going from larger to smaller, multiply. For instance, when 150 nm to μm you are going larger and it is only one 1,000-fold step so divide by 1,000. If you were going from 150 nm to mm you would divide by 1,000 twice.

Question: If microbiology is study of organisms that cannot be seen with the naked eye, when did the science of microbiology begin?

Answer: When the microscope was invented

Replica of Leewenhoek’s Microscope

Question: If this magnified 300X and a bacterium is 4 μm long, how long would it appear to the naked eye?

The microscope and deductive experiments combined to disprove spontaneous generation

Redi’s experiment

Jablot’s experiment

Shultze and Schwann

Pasteur

Development of aseptic technique

•early on people sensed that there was some connection between dirt, garbage, etc and disease (cultural science)

•Semmelweiss showed tha women in the maternity ward often became infected by physicians coming directly from the autopsy room

•Lister introduced aseptic technique into the operating room and operating room deaths dropped significantly

Koch and Pasteur were major players in microbiology

Koch developed Koch’s postulates that are still used today to link a disease to a causative agent. He proved that anthrax was caused by Bacillus anthracis

Pasteur developed the germ theory of disease and developed a vaccine for rabies.

Classification of organisms (us)•Kingdom - Animalia

•phylum or division - Chordata

•Class - Mammalia

•Order - Primates

•Family - Hominoidea

•Genus - Homo

•Species - sapiens

Naming micoorganisms

• Binomial (scientific) nomenclature • Gives each microbe 2 names

– Genus - noun, always capitalized– species - adjective, lowercase

• Both italicized or underlined– Staphylococcus aureus (S. aureus)– Bacillus subtilis(B. subtilis)– Escherichia coli (E. coli)

Classifying Organisms (the classical scheme)

Classifying Organisms Based on rRNA homology