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27 Cards in this Set

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Fatty acids make up membrane chemistry in?

Bacteria and Eukarya. Archaea use Phytanyl.


80 known phyla.


About half of known phyla are known from 16s rRNA gene

PROTEOBACTERIA

- are all gram-negative


- divided into 6 classes: Alpha, Beta, Gamma, Delta, Epsilon, and Zeta where Zeta contains Mariprofundus ferooxydans


-Horizontal gene flow has played a major role in shaping the metabolic diversity of Proteobacteria.

What two things provide different views of prokaryotic diversity?



phenotype and phylogeny

Alphaproteobacteria

-2nd largest class of Proteobacteria


-Most are obligate or facultative anaerobes


-many are OLIGOTROPHIC, grow in env's w/ low nutrient concentration


-vast majority fall within Rhizobiales, Rickettsiales, Rhodobacterales, Rhodospirillales, Caulobacterales, and Sphingomonadales

E. Coli

-can be phototrophic (including the purple sulfur bacteria) chemoorganotrophic, or chemolithotrophic, and can have either respiratory or fermentative metabolism


-Enteric bacteria are oxidase-negative and catalase-positive.


One major taxonomic characteristic separating the various genera of enteric bacteria is the type and proportion of fermentation products generated from the fermentation of glucose

Mixed-acid fermentation and the 2,3-butanediol fermentation

-In the mixed-acid fermentation, three acids are formed in significant amounts: acetic, lactic, and succinic.


-In the butanediol fermentation, smaller amounts of acids are formed, and butanediol, ethanol, CO2, and H2 are the main products


-As a result of mixed-acid fermentation, equal amounts of CO2 and H2 are produced, whereas in the butanediol fermentation, considerably more CO2 than H2 is produced


Salmonella and Shigella

the most common diseases caused by salmonellas are typhoid fever and gastroenteritis.


species of Shigella are typically pathogenic to humans, causing a rather severe gastroenteritis called bacillary dysentery. Shigella dysenteria


Genomic analyses strongly suggest that Shigella and Escherichia have exchanged a signifi- cant number of genes by horizontal gene flow

Proteus



Prodigiosin

typically contains highly motile cells that produce the enzyme urease



is produced in stationary phase as a secondary metabolite and is of interest because it contains the pyrrole ring also found in the pigments for energy transfer: porphyrins, chlorophylls, bacteriochlorophylls, and phycobilins

order Lactobacillales

lactic acid bacteria, fermentative organisms that produce lactic acid as a major end product are nonsporulating, oxidase- and catalase-negative rods or cocci that show an exclusively fermentative metabolism


-Members of this group lack porphyrins and cytochromes, do not carry out oxidative phosphorylation, and hence obtain energy only by substrate-level phosphorylation


-Lactobacilli are typically more resistant to acidic conditions than are other lactic acid bacteria and are able to grow well at pH values as low as 4.

Aerotolerant anaerobes



Homofermentative vs. heterofermentative

aerotolerant anaerobes- can grow in presence of Oxygen


homofermentative, produces a single fermentation product, lactic acid


heterofermentative, produces other products, mainly ethanol and CO2, as well as lactate

Streptococci

divided into two groups of related species: the pyogenes subgroup, characterized by Streptococcus pyo- genes, the cause of strep throat and the viri- dans subgroup, characterized by Streptococcus mutans, the cause of dental caries

Bacillus and Clostridium

contains species that are obligately anaerobic and fermentative. All endospore-forming bacteria are ecologically related because they are found in nature primarily in soil.


Many bacilli produce antibiotics


Several bacilli, most notably Paenibacillus popilliae and Bacil- lus thuringiensis The toxin binds to specific receptors in the intestinal epithelial cells of certain insects and induces pore formation that causes leakage of the host cell cytoplasm followed by lysis.

Firmicutes

Spore-forming


they are halophiles, acidophiles, alkaliphiles

Archaeota

Euryarchaeota, Crenarchaeota, Thaumarchaeota, Korarchaeota, and Nanoarchaeota


-Many metabolic traits of archaeal species are also found in Bacteria, ether-linked lipids, chemo org and chemo litho trophy are common. Autotrophy by 5 diff ways.


Halobacterium

-most extreme halophiles are obligate aerobes


-Electron transport chains containing cytochromes of the a, b, and c types are present in Halobacterium, and energy is conserved during aerobic growth via a proton motive force arising from electron transport.


-must either accumulate or synthesize solutes intracellularly. These solutes are called compatible solutes.


- ribosomes of Halobacterium also require high KCl levels for stability, whereas ribosomes of nonhalophiles have no KCl requirement.

Bacteriorhodopsin

some other haloarchaea synthesize a protein called bacteriorhodopsin and insert it into their cytoplasmic membranes.


- under O2 conditions, PMF is formed and drives ATP synthesis


Hyperthermophilic Crenarchaeota

-hyperthermophilic Crenarchaeota are obligate anaerobe chemo organo/lithotrophs


- have their energy conserved by: electron transfer within the cyto- plasmic membrane leading to the formation of a proton motive force from which ATP is made by way of proton-translocating ATPases


-also inhabit undersea hot springs called hydrothermal vents and sulfur-rich environments, called solfataras---SULFUR RICH


Pyrodictium

the optimum for Pyrodictium is 105°C


-Cells of Pyrodictium are irregularly disc-shaped and grow in culture in a mycelium-like layer attached to crystals of S0The cell walls of Pyrodictium are composed of glycoprotein. Physiologically, Pyrodictium is a strict anaerobe that grows chemolithotrophi- cally on H2 as an electron donor and S0 as an electron acceptor or chemoorganotrophically on complex mixtures of organic compounds

Pyrolobus

Pyrolobus optimum is 106°C maximum is 113°C. P. fumarii lives in the walls of “black smoker” hydrothermal vent chimneys where its autotrophic abilities contribute organic carbon to this otherwise inorganic environment. P. fumarii cells are coccoid-shaped, and the cell wall is composed of protein. The organism is an obligate H2 chemolithotroph, growing by the oxidation of H2 coupled to the reduction of NO3− to ammonium (NH4+), thiosulfate (S2O32−) to H2S, or very low concentrations of O2 to H2O.

Upper temperature limit

many experts predict that the upper temperature limit for prokaryotic life is likely to exceed 140°C, perhaps even 150°C


Upper temperature limit is determined by the thermal stability of macromolecules.

Ribosomal RNA view of Eukaryal Phylogeny

distinguishes microbial eukaryotes as having diverged very early in the evolution of Eukarya. these putative early-branching eukaryotes appeared phenotypically “primitive” as well, lacking mitochondria for example, and this was consistent with their having arisen before primary endosymbiotic events occurred. However, we now know that these amitochondriate eukaryotes contain hydrogenosomes, structures analogous to the mitochondrion. eukaryotic genes include cytoskeleton tubulin proteins, RNA polymerase, ATPase, and heat shock proteins

Events of Eukaryal Evolution

First, it appears that a major phylogenetic radi- ation took place as an early event in eukaryote evolution. This radiation included evolution of the ancestors of all, or virtually all, modern eukaryotic organisms. Second, the composite eukaryal tree shows that amitochondriate eukaryotes, once thought to be basal (early evolving), are instead highly derived organisms, and that animals and fungi are closely related

Endosymbiotic Theory

Following primary endosymbiosis of the cyanobacterial ancestor of chloroplasts by early mitochondrion- containing eukaryotes, these now phototrophic eukaryotes diverged into red and green algae. Then, in secondary endosymbioses, ancestors of the euglenozoans and cercozoans engulfed green algae while ancestors of the alveolates and stramenopiles engulfed red algae. These secondary endosymbioses account for the great phylogenetic diversity of phototrophic eukaryotes and are likely to have occurred relatively recently in evolutionary time.

Red and Green Algae

only product of primary endosymbiosis, large/diverse group of phototrophs, oxygenic photosynthesis, red algae=marine algae and acidic hot springs

FUNGI

-are chemoorganotrophs—and most are aerobic


-Most fungal cell walls consist of chitin, a polymer of N-acetyl- glucosamine


reproduce by asexual means in one of three ways: (1) by the growth and spread of hyphal filaments; (2) by the asexual production of spores (conidia); or (3) by simple cell division, as in budding yeasts


chytridiomycetes

lie phylogenetically basal to all other fungal groups and that the most derived groups of fungi are the basidiomycetes, the ascomycetes, used 18 SSU-rRNA-based phylogeny



The earliest fungal lineage is thought to be the chytridiomycetes, an unusual group of motile fungi in which cells produce flagellated spores


sister group with animals because they diverged 1.5 M years ago



Fungal Reproduction

chytrids- fruiting bodies contain zoospores, live in aquatic environments, amphibian diseases


zygomycetes/glomeromycetes- food spoilage and mycorhizae


ascomycetes- unicellular to hyphae formations, all form from asci, and reproduce sexually important in wood decay


basidiomycetes-edible and can be poisonous, mushroom=basidium