Lesson 6: Classification of bacteria Flashcards
are heterogeneous group of several distinct classes of living beings.
microorganisms
example in group prokaryotes
kingdom protista, bacteria and blue-green algae
example in group eukaryotes
fungi, other algae, slime molds and protozoa
Nucleus
Prokaryotes: Absent. No nuclear envelop
Eukaryotes: Present with nuclear envelope and nucleolus
Membrane-bound organelles
Prokaryotes: Absent
Eukaryotes: Present. includes mitochondria, chloroplasts (plants), lysosomes
Chromosome (DNA)
Prokaryotes: Single Coiled chromosome
Eukaryotes: Multiple linear chromosomes
Cell Wall
prokaryotes: eubacteria have a cell wall of peptidoglycan
eukaryotes: no cell wall in animal cells
plant cell walls is cellulose
fungal cell walls is chitin
mitotic division
prokaryotes: absent
eukaryotes: present
Ribosomes
prokaryotes: 70S
eukaryotes: 80S
Flagella
prokaryotes: free in cytoplasm
eukaryotes: consist of 9+2 arrangement of microtubules
cytoplasmic membrane lipids
prokaryotes: eubacteria: fatty acids joined to glycerol by ester linkage
eukaryotes: fatty acids joined to glycerol by ester linkage
mitochondria
prokaryotes: absent
eukaryotes: present
lysosomes
prokaryotes: absent
eukaryotes: present
golgi apparatus
prokaryotes: absent
eukaryotes: present
endoplasmic reticulum
prokaryotes: absent
eukaryotes: present
helps in identification of organisms according to groups based on its common characteristics and traits hence distinguishing one organism from another
classification
according to mode of nutrition
phototrophs
chemotrophs
autotrophs
heterotrophs
bacteria which gain energy from light
phototrophs
two groups of phototrophs on the basis of source of electron
a. photolithotrops
b. photoorganotrops
bacteria that uses reduced inorganic compounds such as H2S as electron source
photolithotrops
uses organic compounds such as succinate as electron source
photoorganotrops
bacteria which gain energy from chemical compounds and cannot carry out photosynthesis.
chemotrophs
chemotrophs subdivided into two groups on the basis of source of electron.
a. chemolithotrops
b. chemoorganotrops
they gain energy from oxidation of chemical compound and reduces inorganic compounds such as NH3 as electron source
chemolithotrops
they gain energy from chemical compounds and uses organic compound such as glucose and amino acids as source of electron
chemoorganotrops
nonpathogenic, free-living bacteria which uses solar energy or carbon dioxide as sole source of carbon to prepare its own food.
autotrophs
autotrophs subdivided into two types on the basis of energy utilized to assimilate carbon dioxide:
a. photoautotrophs
b. chemoautotrophs
they utilized light to assimilate carbon dioxide
photoautotrophs
photoautotrophs further subdivided into two groups on the basis of electron sources;
photolithotropic autotrops and photoorganotropic autotrops
they utilize chemical energy for assimilation of carbon dioxide.
chemoautotrops
bacteria which uses organic compound as carbon source and lack the ability to fix carbon dioxide
heterotrophs
bacteria that can grow at below 0°C to 20°C but the optimum temperature of growth is 15°C or below
psychrophiles
(facultative psychrophiles) bacteria that can grow even between 0°C to 30°C but optimum temperature for growth is 20-30°C.
psychrotrophs
bacteria that can grow best between 25-40°C and optimum temperature for growth is 37°C.
mesophiles
bacteria that best grow above 45°C, contains saturated fatty acids in their cell membrane so their cell membrane does not become too fluid even at higher temperature, can survive pasteurization temperature.
thermophiles
capable for growing in mesophilic range
facultative thermophiles
true thermophiles or stenothermophiles
obligate thermophiles
bacteria that have optimum temperature of growth above 80°C
hypethermophiles
bacteria that grows best at acidic pH
acidophiles
bacteria that grows best at alkaline pH
alkaliphiles
bacteria that grows best at neutral pH (6.5-7.5)
neutrophiles
bacteria that require high concentration of sodium chloride (NaCl) for growth
halophiles
bacteria that does not require NaCl but can tolerate low concentration of NaCl in growth medial
halotolerant
bacteria that requires and cannot grow in the absence of oxygen
obligate aerobes
bacteria that do not require but can tolerate the presence oxygen for growth
aerotolerany anaerobes
bacteria that do not require but can tolerate low concentration of oxygen for growth
microaerophiles
bacteria that can grow only in absence of oxygen
obligate anaerobes
bacteria that require carbon dioxide for growth
capnophiles
cell wall of these bacteria is composed of peptidoglycan layer only. the cell wall retains the crystal fire lit or gram stain which appear violate in gram staining
gram positive bacteria
cell wall of these bacteria is composed of thin layer peptidoglycan and outer membrane lipopolysaccharide. the cell wall does not retain the gram stain, but they take up the red color of the counter stain during gram staining
gram negative bacteria
bacteria with single flagellum in one end of cell
monotrichous
bacteria having bundle of flagella in one end of cell
lophotrichous
bacteria having single or cluster of flagella at both end of cell
amphitrichous
bacteria having flagella evenly distributed around the cell surface
peritrichous
bacteria without flagella
atrichous
produce spore during unfavorable condition
spore forming bacteria
those bacteria which do not produce spore
non-spore forming bacteria
spore forming bacteria subdivided into two groups:
a. endospore forming bacteria
b. exospore forming bacteria
spore produced within the bacterial cell
endospore forming bacteria
spore produced outside the cell
exospore forming bacteria