Transcript Intro To Biology - LBHS Biology | The study of life

Taxonomy
I. General Information
A. Definition: the study of classification.
B. Why group things?
1. Makes it easier to find information on
an organism.
2. Makes it easier to identify an
organism.
3. Shows evolutionary relationships.
Taxonomy
Microbiology 2314
Taxonomy
The science of biological classification, by
grouping organisms with similar characteristics.
Three Interrelated Parts of
Taxonomy
• Classification
Arrangement into groups
• Nomenclature
Assignment of Names
• Identification
Determining Identity
Two Kingdom
System
(Proposed by Aristotle)
• Plantae
Bacteria
Fungi
Algae
Plants
Two Kingdom
System
• Animalia
Animals
Protozoa
Problem with Aristotle’s
Classification System:
If it was green, it was a
plant regardless of other
features.
Five Kingdom System
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Animalia
Plantae
Fungi
Protista
Procaryote/Monera
Animalia
1. Multicellular
2. Heterotrophs
Plantae
1. Multicellular
2. Photoautotrophs
Fungi
1. Absorptive
Chemoheterotrophs
2. Decomposers
Protista
1. Unicellular
2. Autotrophic
or
Heterotrophic
Monera
(Bacteria)
Six Kingdom System
Three Domain System
(Difference in rRNA and Cell Wall in Procaryotic Organisms)
• Domain Eukaryae
All Eukaryotic Organisms
• Domain Eubacteria
True Bacteria and Cyanobacteria
• Domain Archaea
Ancient “Extreme” Bacteria
Taxonomic Hierarchy
Domain
(Carl Woese 1978)
Kingdom
Phylum/Division
Class
Order
Family
Genus
Species
Domains
Carolus Linnaeus
1753
1. Kingdom Through Species
2. Binomial Nomenclature
3. Bacillus subtilis
Bacillus subtilis
3. Common/Descriptive Names
Tubercule Bacillus
Mycobacterium tuberculosis
Dichotomous Keys
1a. Bean round
Garbanzo Bean
1b Bean elliptical or oblong
Go to 2
2a Bean white
White Navy
2b Bean dark
Go to 3
3a. Bean evenly pigmented
Kidney Bean
3b Bean pigmentation mottled
Pinto Bean
Phylogenetic Classification
• Genetic Similarity and Evolutionary Relatedness
Reflects Genetic Similarity and Evolutionary Relatedness
Charles Darwin
Protista
Phenetic Classification
• Based on Observable Characteristics.
Species verses Strain
• Species
A specific or defined type of organism
capable of producing young that can
also reproduce.
• Strain
Variation within a species.
• descended from a single organism
• different isolates may be same species but are different strains;
often have slight differences
Bergey’s Manual of Systematic
Bacteriology
•First edition published in 1923, now in 9th edition.
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•Uses both morphological and Physiological
characteristics
•Very practical system. Use successive "key"
features to narrow down identification
•Ex. Gram + or -? Then shape? Then motile or
not? etc. Eventually only a few organisms match
the process of elimination.
•Second edition now being published, a major reorganization
•Primary emphasis is phylogenetic, not phenetic
•Example: pathogens are not grouped together, instead they are
scattered in different areas
•Five volumes have instructive titles:
The Archaea, and the Deeply Branching and
Phototrophic
Bacteria
The Proteobacteria
The Low G + C Gram-positive Bacteria
The High G + C Gram-positive Bacteria
The Planctomyces, Spirochaetes, Fibrobacters,
Bacterioidetes,
and Fusobacteria
American Type Culture
Collection
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Algae and Protozoa
Bacteria and Baceriophages
Cell Lines
DNA Materials
Fungi and Yeasts
Plant Tissues
Seeds
Viruses and Virus Antiserum
Eukaryotic
Cells
Domain Eukaryae
1. Membrane System
2. Compartmentalization
3. Membrane Enclosed
Organelles
4. Nucleus
Prokaryotic
Cells
Domain Eubacteria
& Archaea
1. Few if Any Internal
Membranes
2. Plasma Membrane
Mediates Internal
Processes
3. Nucleoid
4. No Membrane Bound
Organelles
Viruses
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Noncellular
Nonliving
Either DNA or RNA
Capsid (Protein Shell)
Envelope
Viruses
• Virus Species
A population of viruses with similar
characteristics that occupy a particular
ecological niche.
• No Independent Metabolism or
Replication
• Requires a Host (Parasitic)
Viral Replication
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5.
Attachment
Penetration
Disassembly
Reassembly
Release
Major Criteria and Methods
Used in the Taxonomy of
Microorganisms
Classical Approach
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Morphology
Differential Staining
Biochemical Tests
Oxygen Requirements
Serology
Phage Typing
Molecular Approach
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Amino Acid Sequencing
Total Protein Analysis
Base Composition
Nucleic Acid Hybridization
Numerical Taxonomy
Fatty Acid Profiles
Cladogram
FYI
Bacteria Consist of Approximately
12 Distinct Groups
Biologists say greensulfur bacteria are
important because they
perform photosynthesis in
a different way from that
of other bacteria and that
of plants. Obligately
anaerobic
photolithoautotrophs that
use hydrogen sulfide,
elemental sulfur and
hydrogen as electron
sources; elemental sulfur
produced by sulfide
oxidation is deposited
outside the cell . Have gas
vessicles because they
lack flagella and are
nonmotile unless moved
by environment.
Merismopedia
Cyanobacteria have
historically been essential
for the developing of
more complicated life
forms by the production
of oxygen in our
atmosphere. Largest and
most diverse group of
photosynthetic bacteria.
Photosynthetic system
resembles that of
eucaryotes, having
chlorophyll a and
photosystem II; carry out
oxygenic photosynthesis
The Gram-positive cocci are the leading pathogens of
humans. It is estimated that they produce at least a third
of all the bacterial infections of humans, including strep
throat, pneumonia, food poisoning, various skin
diseases and severe types of septic shock.
• Purple bacteria (anaerobic) use energy from the
sun but extract electrons from substances other than
water, and therefore release no oxygen. Most species
are strict anaerobes and live in the sediment of ponds
and lakes. These bacteria deposit sulfur granules
outside their cells.
• Chlamydiae are tiny bacteria that infect birds
and mammals. They may colonize and infect
tissues of the eye and urogenital tract in
humans. Chlamydia trachomatis causes
several important diseases in humans:
chlamydia, the most prevalent sexually
transmitted disease in the U.S. Chlamydia
pneumoniae is a cause of pneumonia and has
been recently linked to atherosclerosis.
• Planctomyces is a
marine bacterium that
can be found in
various habitats
around the world.
Planctomycetes in
general are intriguing
because they are the
only free living
bacteria known to lack
peptidoglycan in their
cell walls.
Cytophaga is an endotoxin-producing bacteria that can
cause respiratory disease if inhaled and is common in soil
and both freshwater and marine environments. Cytophaga
are unicellular, gram-negative gliding bacteria. Some strains
can move at speeds near 10 µm per second. Due to this
motility, colonies form spreading swarms on agar and some
can cover entire plate in a few days. Cytophaga are
chemoheteroorganotrophs, and many of them are able to
degrade biomacromolecules such as protein, DNA, RNA,
chitin, pectin, agar, starch, or cellulose.
The spirochetes are a
phylogenetically distinct group
of bacteria which have a unique
cell morphology and mode of
motility. Spirochetes are very
thin, flexible, spiral-shaped
procaryotes that move by means
of structures called axial
filaments or endoflagella.
• Deinococci are extraordinarily resistant to
desiccation and radiation: can survive 3-5
million rad whereas 100 rad can be lethal to
humans. An acid producer. Two
Chromosomes.
• Can be isolated from ground meat, feces,
air, fresh water, and other sources but their
natural habitat is not known
• Have an unusual ability to repair
chromosomal damage and this probably
accounts for their ability to resist radiation
• Green Nonsulfur Bacteria
– Filamentous, gliding bacteria
– Thermophilic, often isolated from neutral to
alkaline hot springs where they grow in the form
of orange-reddish mats
– Ultrastructure and photosynthetic pigments are
like green bacteria, but their metabolism is
similar to that of the purple nonsulfur bacteria
• Thermotoga - second deepest branch of the
bacteria. Hyperthermophiles with an
optimum of 80°C and a maximum of 90°C
• Gram-negative rods with an outer sheathlike envelope (like a toga) that can balloon
out from the ends of the cell
• Grow in active geothermal areas (e.g.,
marine hydrothermal vents and terrestrial
sulfur springs)
• Aquifex are thought to represent the
deepest (oldest) branch of bacteria
• Hyperthermophilic
• Chemolithoautotrophic-generate energy
by oxidizing electron donors such as
hydrogen, thiosulfate, and sulfur with
oxygen as the electron acceptor