Nester Chapter 11 Microbiology

Hydrogen Oxidizing bacteria

Aerobic Chemolithotrophs that are one of the earliest bacterial forms to exist on earth: H2 + 0.5O2 = H2O

Filamentous Sulfur Oxidizers

Aerobic chemolithotroph sulfur-oxidizing bacteria that store sulfur, depositing it as intracellular granules, but differ in the nature of their filamentous growth

Sulfur Oxidizing bacteria

Aerobic chemolithotrophs that are gram- rods or spirals which sometimes grow in filaments. They obtain energy by oxidizing elemental sulfur and reduced sulfur compounds, including hydrogen sulfide and thiosulfate. O2 serves as a terminal electron acceptor, generating sulfuric acid S + 1.5O2 + H2O = H2SO4; these bacteria are important in the sulfur cycle

Lactobacillus

Rod shaped lactic acid bacteria that grow as single cells or loosely associated chains and are common member of the microbiota in the mouth and the healthy vagina during childbearing years (helps prevent vaginal infections)

Acidithiobacillus

Unicellular sulfur oxidizing bacteria that is used to prevent acid rain, but can also cause severe environmental problems.

Cyanobacteria

a diverse group of more than 60 genera of Gram- oxygenic phototrophs. Many are capable of nitrogen fixation

Obligate aerobes

aerobic chemoorganotroph organisms that obtain energy using respiration exclusively; none can ferment

Facultative anaerobes

aerobic chemoorganotrophs that preferentially use aerobic respiration if O2 is available. As an alternative, however, they can ferment.

Unicellular Sulfur Oxidizers

aerobic chmolithotroph sulfur-oxidizing bacteria that are found in both terrestrial and aquatic habitats, where their ability to oxidize metal sulfides can be used for bioleaching, a process used to recover metals;oxidize insoluble metal sulfides such as gold sulfide, producing sulfuric acid

rhodobacter rhodopseudomonas

examples of purple non-sulfur bacteria

chromatium thiospirillum thiodictyon

examples of purple sulfur bacteria

Nitrogen fixation

exclusive ability of prokaryotes to convert nictrogen gas (N2) to ammonia.

Propionibacterium

fermentative anaerobic chemoorganotrophs that are species of gram+ pleomorphic (irregular-shaped) rods that produce priopionic acid as their primary fermentation and product. Important in Swiss cheese production (nutty flavor)

purple non sulfur bacteria

purple bacteria found in moist soils, bogs, and paddy fields. use a variety of organic molecules rather than hydrogen sulfide as a source of electrons for reducing power, no gas vesicles

purple sulfur bacteria

purple bacteria that can sometimes be seen growing as colored masses in sulfur-rich habitats such as sulfur springs. Relatively large, some motile by flagella, have gas vesicles, store sulfur in granules. Use hydrogen sulfide as reducing power

anoxic

when the atmosphere is devoid of O2

Aerobic Chemoorganotrophs

Organisms that oxidize organic compounds to obtain energy, using O2 as a terminal electron acceptor: Organic Compounds + O2 = CO2 + H2O

Micrococcus

Obligate aerobes that are Gram+ cocci found in soil and on dust particles, inanimate objects, and skin; often airborne so can easily contaminate;

Pseudomonas

Obligate aerobes that are gram- rods that have polar flagella and often produce pigments; extremely diverse biochemical capabilities = important role in degradation

Mycobactericum

Obligate aerobes that re widespread in nature and include harmless saprophytes as well as pathogens. Have mycolic acid in cell wall (acid=fast); generally pleomorphic rods; causes tuberculosis and hansen's disease

Aerobic Chemolithotrophs

Organisms that obtain energy by oxidizing reduced inorganic chemicals, using O2 as a terminal electron acceptor.

Sulfur and sulfate reducing bacteria

Bacteria that grow anaerobically often and use sulfur or sulfate as a terminal electron acceptor. organic compound + S = CO2 + H2S These are thermophiles if bacteria, and hyperthermophiles if archaea

Nitrogen fixing cyanobacteria

Cyanobacteria that can incorporate both N2 and Co2 into organic material, so they generate a form of these nutrients that can then be used by other organisms.

Nitrifiers

Diverse group of Gram- aerobic chemolithotrophs bacteria that obtain energy by oxidizing inorganic nitrogen compounds such as ammonia or nitrite.

Corynebacterium

Facultative anaerobes that are Gram+ pleomorphic rods, often club-shaped and arranged to form V shapes or palisades. Many reside harmlessly in the throat, but toxin-producing strains can cause the disease diphtheria.

Enterobacteriaceae

Facultative anaerobes that ferment glucose and, if motile, generally have peritrichous flagella. Usually reside in the intestinal tracts of humans and other animals

Desulfovibrio

Gram negative curved rod bacteria that a sulfur reducing

Lactic acid bacteria

Gram+ bacteria that produce lactic acid as a major end product of their fermentative metabolism make up a group called ________

Lactococcus

Lactic acid bacteria that is used by the diary industry to produce fermented milk products such as cheese and yogurt.

Enterococcus

Lactic acid bacteria that typically inhabits the intestinal tract of humans and other animals.

Amonia oxidizers

Nitrifier bacteria that converts ammonia to nitrite: NH4 + 1.5O2 = NO2^- + H2O + 2H^+

Nitrite Oxidizers

Nitrifier bacteria that converts nitrite to nitrate: NO2^- + 0.5O2 = NO3^- Prevents the build up of nitrite in soils, which is toxic and can leach into groundwater

Filamentous anoxygenic phototrophic bacteria

anoxygenic phototrophic bacteria that exhibits gliding motility. Most thoroughly studied of this group are members of the genus Chloroflexus

purple bacteria

anoxygenic phototrophs that are gram- organisms that appear red, orange, or purple die to their light-harvesting pigments.

Coryneform

bacteria that exhibit the shape V

Clostridium

genus of fermentative anaerobic chemoorganotrophs that are gram+ rods that can form endospores.

Green Bacteria

gram- anoxygenic phototrophs that are typically green or brownish in color.

Green sulfur bacteria

green bacteria that is found in habitats similar to those preferred by the purple sulfur bacteria. Also use hydrogen sulfide as a source of electrons for reducing power.

methanogens

group of archaea that generate ATP by oxidizing hydrogen gas, using CO2 as a terminal electron accceptor; anaerobic chemolithotrophs 4H2 + CO2 = CH4 + 2H2O

Streptococcus

lactic acid bacteria cocci that typically grow in chains of varying lengths and inhibit the oral cavity as part of the normal microbiota.

Thermus

obligate aerobe that is thermophilic, have unusual cell wall, and stain Gram-. Taq Polymerase

Deinococcus

obligate aerobes that have unusual cell wall with multiple layers, and stains gram+; can resist damaging effects of gamma radiation = clean up radioactive wastes

chemotrophs

organisms that harvest energy by oxidizing chemicals organisms that get energy from chemical taken from the environment; energy source is preformed molecules, not sunlight.

Primary producers

organisms that harvest the energy of sunlight, using it to convert CO2 into organic compounds. Like Oxygenic Phototrophs.

Anaerobic Chemoorganotrophs

organisms that oxidize organic compounds such as glucose to obtain energy.

Chemoorganotrophs

organisms that oxidize organic compounds such as glucose to obtain energy.

Anaerobic Chemolithotrophs

organisms that oxidize reduced inorganic chemicals such as hydrogen gas (H2) to obtain energy

chemolithotrophs

organisms that oxidize reduced inorganic chemicals such as hydrogen gas (H2) to obtain energy

Oxygenic phototrophs

organisms that use water as a source of electrons for reducing power, generating O2: 6CO2 + 6H2O = C6H12O6 + 6CO2 Cyanobacteria is an example

Heterocysts

specialized thick-walled cells which lack photosystem II and where the process of nitrogen fixation happens (to isolate nitrogenase from O2)

anoxygenic phototrophs

the earliest photosynethsizing organisms. Rather than using water a s a source of electrons when making reducing power for biosynthesis, these organisms use hydrogen sulfide or organic compounds, and therefore do not generate O2.

Methanospirillum methanosarcina

two examples of methanogens

Bacteriochlorophyll

unique type of chlorophyll in anoxygenic phototrophs that absorbs wavelengths that penetrate deeper than those absorbed by chlorophyll a