The microbial world

S. Cerevisiae (yeast)

Mycobacterium tuberculosis

Taxonomy – branch of biology concerned with grouping and naming organisms

Classifying Life

Historical Classification Systems-Used only morphological characteristics

-Anatomy-Physiology-Fossil record

Current Classification System-Uses genetic sequences (DNA, RNA, protein)

-along with morphological data

3 Domain System-Bacteria and Archaea domains contain prokaryotes-Domain Eukarya split into supergroups

Eukarya further grouped into kingdom, phylum, class, order, family, genus, and species

Classifying LifeCurrent Classification System

Group organisms based on evolutionary relatedness

Bacteria Archea Eukarya

Metagenomics - study of all the DNA in a particular environment

Minnesota Mississippi Metagenomics Project

Project examining the microbial diversity along the Mississippi River

Exploring microbial diversity

Microbial World

DNA is isolated and sequenced

Can be used to identify and group the organisms, as well as indicate functionality

Domain Bacteria - The Cyanobacteriaexample: Gleocapsa

Autotrophic (“self feeding”) – makes organic molecules from inorganic ones.

Phototrophic – obtain energy from light

Prokaryotic –no membrane-enclosed organelles (no nucleus)

Domain Eukarya; Kingdom Eulgenozoaexample: Euglena

Mixotroph - obtains food from inorganic sources and organic sources (other living organisms)

Stigma (eye-spot)

Flagellum

Domain Eukarya; Kingdom ViridiplantaePhylums Chlorophyta & Streptophyta

Photoautotrophic – photosynthesizes

Closely related to plants

Example: Spirogyra

Example: Volvox

Example: Chlamydomonas

Domain Eukarya; Kingdom Alveolataexamples: Paramecium and Blepharisma

Heterotrophic (“other feeding”) – ingests other organisms

Chemotrophic – obtain energy from oxidation of organic molecules

Phylum Rhizopodaexample: Amoeba

Chemoheterotrophic – engulfs preyphagocytosispinocytosis

Pseudopodia (“false feet”)-Cytoplasmic extensions