CH 11: Characterizing and Classifying Prokaryotes

What is a pleomorphic prokaryote?

A prokaryote whose cell morphology varies in shape and size

_______ form when planes of cell division are random.

Staphylococci

All are taxonomic domains except

Protista

Which of the following does not have a high G+C content?

Lactobacillus

Which of the following is not a characteristic of pseudomonads?

They are in the deltaproteobacteria group

A ___________ is a lightly curved rod.

vibrio

What is the difference between spores and endospores?

spores are reproductive structures; endospores are stable resting structures

Which of the following is a unique characteristic of mycoplasms?

they lack a cell wall

If organism X has a G+C content of 60% and organism Y has a G+C content of 35%, which of the following is most likely?

they are not closely related

Which of the following is not a characteristic of the betaproteobacteria?

they are similar to alphaproteobacteria according to rRNA

Prokaryotes

most diverse group of cellular microbes, thrive in various habitats, few capable of colonizing humans and causing disease

Endospores

produced by Gram + bacteria Bacillus and Clostridium

Each vegetative cell transforms into

One endospore

Each endosopre germinates to form

One vegetative Cell

Reproduction of prokaryotic cells

Asexually

Three metods of asexual reproduction

Binary fission, snapping division, budding

Arrangements of pro cells- two aspects of division

Planes in which cells are divided, separation of daughter cells

Prokaryotic classification

based on genetic relatedness of rRNA sequences

Three domains

archaea, bacteria, eukarya

Clostridia

rod-shaped obligate anaerobes. Important in medicine and industry

Types of clostridia

c. perfingens, c. difficile, c. tetani, c. botulinum

Mycoplasma

lack cell walls, fried egg appearance, smallest free-living cells

Bacillus

Common in soilB

Bacillus thuringienisis

Used as insecticide

Bacillus anthracis

causes anthrax

Listefria monocytogenes

contaminates meat/milk, capable of reproduction after refrigeration, can cross placenta in pregnant women

Lactobacillus

Grows in body, rarely causes disease, “good” bacteria, used in production of various foods

Streptococcus and ENterococcus

Causes disease, various strains of multi-drug resistant streptococci

Staphylococcus

Common inhabitant in humans, produces toxins and enzymes that contribute to disease in pathogenic species/strains

Coryne bacterium

pleomorphic aerobes + faculitative anaerobes, produces metachromatic granules

Mycobacterium

Aerobicrods that can form filaments, slow growth due to mycolic acid in cell walls

Actinomyces

Form branching filaments resembling fungi

Gram negative protobacteria

Largest, most diverse group of bacteria

Six classes of proteobacteria

Alpha, beta, gamma, delta, epsilon, zeta

Gram - alphaproteobacteria

Environmental microbes, not pathogenic, nitrogen fixers, nitrifying bacteria, purple non-sulfur phototrophs

Rickettsia (alpha)

transmitted through arthropod bite, causes human diseases

Brucella (alpha)

caused brucellis

Weisseria (beta)

inhabits mucous membranes of mammals, causes disease

Bordetella (beta)

Causes pertussis (whooping cough)

Burkholderia

colonizes moist environment surfaces and respiratory passages of cystic fibrosis patients

Gammaproteobacteria

largest, most diverse

Leginella (gamma)

causes Legionnaires’ disease

Coxiella (gamma)

causes Q fever

Glycolytic faculatative anaerobes

catabolize carbs by glycolysis and the pentose phosphate pathway

3 families

enterobacteriaceae, vibrionaeeae, pasturellaaceae

Pseudomonads

Break down organic compounds, protable for polar flagella, carry UT, ear, and lung infections

Gram negative deltaproteobacteria

Wide variety of metabolic types. desulfovibria, Bdellovibria, myxobacteria

camplyobacter (epsilon)

gastroenteritis, foodborne

Helicobacter

Stomach ulcers

Chlamydias

grow intracellularly, smaller than viruses

Chlamydia trachomatis

most common sexually transmitted bacteria in US, leading cause of blindness in developing countries

Spirochetes

motile bacteria, move in corkscrew motion, diverse metabolism and habitats

Treponema pallidum

Syphilis, yews

Bomelia burgdorferi

lyme disease

Bacteroides

Inhabit digestive tracts, good bacteria, some species cause infection