Microbial Diversity Lecture Review

Flashcards for vocabulary review of microbial diversity lecture notes.

Enteric Bacteria

Oxidase-negative and catalase-positive bacteria that produce acid from glucose and reduce nitrate only to nitrite.

Taxonomic characteristic separating enteric bacteria genera

The type and proportion of fermentation products generated from the fermentation of glucose.

Mixed-Acid Fermentation

A fermentation where acetic, lactic, and succinic acids are formed in significant amounts, alongside ethanol, CO2, and H2.

2,3-Butanediol Fermentation

A fermentation where smaller amounts of acids are formed, and butanediol, ethanol, CO2, and H2 are the main products.

Escherichia Species

Inhabitants of the intestinal tract of humans and other warm-blooded animals, playing a nutritional role by synthesizing vitamins, particularly vitamin K.

Salmonella species

Species that cause typhoid fever and gastroenteritis in humans.

Shigella species

Species that are typically pathogenic to humans, causing a severe gastroenteritis called bacillary dysentery.

Proteus

Bacteria that contains highly motile cells that produce the enzyme urease and is also a frequent cause of urinary tract infections in humans.

Enterobacter aerogenes

Common species in water and sewage as well as the intestinal tract of warm-blooded animals and is an occasional cause of urinary tract infections.

Serratia

Forms a series of red pyrrole-containing pigments called prodigiosins and can be isolated from water and soil.

Pseudomonas aeruginosa

A common cause of lung infection in cystic fibrosis patients.

Phytopathogens

Plant pathogens that release plant toxins, lytic enzymes, plant growth factors, and other substances that destroy or distort plant tissue.

Vibrionales

Contains facultatively aerobic rods and curved rods that employ a fermentative metabolism.

Vibrio cholerae

Causes the disease cholera in humans and is transmitted almost exclusively via water

Vibrio parahaemolyticus

Inhabits the marine environment and is a major cause of gastroenteritis in Japan, where raw fish is widely consumed.

Deltaproteobacteria

Primarily sulfate- and sulfur-reducing bacteria, dissimilative iron-reducers, and bacterial predators.

Epsilonproteobacteria

Contains many species that oxidize the H2S produced by the sulfate and sulfur reducers.

Campylobacter Species

Cause acute gastroenteritis that typically results in a bloody diarrhea and Pathogenesis is due to several factors, including an enterotoxin that is related to cholera toxin.

Helicobacter pylori

Causes both chronic and acute gastritis, leading to the formation of peptic ulcers.

Syntrophobacter wolinii

Oxidize propionate, producing acetate, CO2, and H2, but such growth is only possible when a H2-consuming partner is present.

Myxococcales and Bdellovibrionales

Eight orders that have been well characterized within the Deltaproteobacteria.

Lactic Acid Bacteria

Fermentative organisms that produce lactic acid as a major end product of metabolism.

Homofermentative

Produces a single fermentation product, lactic acid.

Heterofermentative

Produces other products, mainly ethanol and CO2, as well as lactate.

Lactobacilli

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

Pyogenes subgroup

Produce the virulence factors streptolysin O or S and form colonies surrounded by a large zone of complete red blood cell hemolysis when plated on blood agar, a condition called b-hemolysis

Viridans subgroup

Cause incomplete hemolysis on blood agar, a condition that leads to greening of the agar under colonies.

Leuconostoc

Strains also produce the flavoring ingredients diacetyl and acetoin from the catabolism of citrate; they have been used as starter cultures in dairy fermentations.

Staphylococcus

Facultative aerobe that shows a typical respiratory metabolism but can also grow fermentatively, resistant to reduced water potential and tolerate drying and high salt (NaCl) fairly well.

Staphylococcus species

Typically grow in clusters and produce acid from glucose both aerobically and anaerobically.

Sarcina

Obligate anaerobes that are catalase-negative and divide in three perpendicular planes to yield packets of eight or more cells

Listeria

Gram-positive, catalase-positive, rod-shaped, facultatively aerobic chemoorganotrophs found widely in soils and is an opportunistic pathogen and a common cause of foodborne illness.

Clostridia

Lack a respiratory chain and so they obtain ATP by substrate-level phosphorylation.

Cellulosomes

Complex multienzyme structures found on the outer surface of the cell wall, that binds insoluble cellulose and degrades it into soluble products that are transported into the cytoplasm and metabolized by the cell.

Stickland Reaction

Coupled catabolism of an amino acid pair.

Sporosarcina

Aerobic spherical to oval cells that divide in two or three perpendicular planes to form tetrads or packets of eight or more cells and catabolizing urea to CO2 and ammonia (NH3), which dramatically raises the pH.

Tenericutes/Mycoplasmas

Bacteria that lack cell walls and are some of the smallest organisms known.

Spiroplasma

Helical or spiral-shaped Mollicutes that although they lack a cell wall and flagella, spiroplasmas are motile by means of a rotary (screw) motion or a slow undulation.

Coryneform bacteria

Gram-positive, aerobic, nonmotile, rod-shaped organisms with form irregular-shaped, club-shaped, or V-shaped cell arrangements during growth.

Snapping Division

Forms irregular-shaped, club-shaped, or V-shaped cell arrangements during growth due to an abrupt movement that occurs just after cell division and only the inner layer participates in cross-wall formation

Propionic Acid Bacteria

First discovered in Swiss (Emmentaler) cheese, where their fermentative production of CO2 produces the characteristic holes.

Mycobacteria

Possess the distinctive staining property called acid-fastness.

Mycolic acids

Group of complex branched-chain hydroxylated lipids covalently bound to peptidoglycan in the cell wall giving the surface a waxy, hydrophobic consistency

Actinomycetes

Filamentous and aerobic gram-positive Bacteria common in soils

Mycelium

Network of filaments

Sporophores

Aerial filaments that project above the surface of the colony and give rise to spores.

Conidia

Produced by the formation of cross-walls in the multinucleate sporophores followed by separation of the individual cells directly into spores

Geosmin

A series of complex metabolites produced by streptomycetes and causes the characteristic earthy odor of soil

Bacteroidales

Obligately anaerobic fermentative species that are saccharolytic, fermenting sugars or proteins to acetate and succinate as major fermentation products.

Bacteroides thetaiotaomicron

Specializes in the degradation of complex polysaccharides and thus vastly increases the diversity of plant polymers that can be degraded in the human digestive tract.

Bacteroides

Special type of lipid called sphingolipid, a collection of lipids characterized by the long-chain amino alcohol sphingosine in place of glycerol in the lipid backbone

Cytophagales

Long, slender, gram-negative rods and specialize in the degradation of complex polysaccharides

Exoenzymes

Secrete processive endocellulases, which cleave internal b-1,4 glycosidic bonds, and processive exocellulases, which cleave terminal b-1,4 glucosidic bonds, releasing cellobiose.

Cytophaga hutchinsonii

Requires physical contact of cellulose fibers with cellulase enzymes located on the outer surface of its cell wall for cellulose degradation

Flavobacteriales and Sphingobacteriales

Rustically obligate aerobes though some species are able to reduce nitrate

Chlamydiae, Planctomycetes

Organisms that lack a gene encoding the protein FtsZ, a key protein in septum formation during cell division

Elementary Body/Reticulate Body

Small, dense cell and is relatively resistant to drying and is the means of dispersal/larger, less dense cell,which divides by binary fission and is the vegetative form

Anammox Bacteria and Anammoxosome

Catalyze the anaerobic oxidation of ammonia (NH3) within the anammoxosome structure and membrane composed of unique lipids that form a tight seal, protecting cytoplasmic components from toxic intermediates produced during the anaerobic oxidation of ammonia

Aquifex

Can tolerate only very low O2 concentrations (microaerophilic), and is unable to oxidize any tested organic compound, autotrophy occurs by way of the reverse citric acid cycle

lipid A

Outer membrane of deinococci lack

Thermus aquaticus

Discovered in a Yellowstone National Park hot spring and has been a model organism for studying life at high temperatures, T. aquaticus has subsequently been isolated from many thermal systems including private and commercial hot water heaters and is the source of Taq DNA polymerase

D. radiodurans DNA Repair

Efficient in repairing damaged DNA (several DNA repair enzymes exist) and then facilitated by the fusion of nucleoids from adjacent compartments, because their toroidal structure provides a platform for homologous recombination

Acidobacteria

Common in soils, and especially in acid soils (pH < 6.0), where they often comprise a majority of soil microbial communities.

Pyrinomonas

Methylaliphatogenes is isolated from thermally heated soil; this species is notable, however, because it can generate energy, but not grow, using atmospheric H2

Some species of Nitrospira in soils

Complete pathway for nitrification, oxidizing ammonia all the way to nitrate

Fusobacteria

Have adhesions, molecules that allow them to form strong attachments to other cells, both bacterial and animal and those adhesions allow Fusobacteria to play an important structural role in the formation of biofilms called dental plaque in the oral cavity are called

Fibrobacter

An organism in the rumen that specializes in cellulose fermentation.

Deferribacter

A thermophilic dissimilative ferric iron-reducer that can also reduce nitrate and metal oxides.

Chrysiogenes arsenatis

An organism with the ability to couple the oxidation of acetate and a few other organic compounds to the reduction of arsenate as a terminal electron acceptor, reducing it to arsenite.