Transcript Document

Psychrophiles, cells that grow best at low
temperatures below 20oC
 Mesophiles have temperature optima in
the range of 20 to 50oC
 Thermophiles grow best at temperatures
greater than 50oC.

Aerobic microorganisms require O2 for
growth and metabolism.
 Anaerobic microorganisms are inhibited
by the presence of O2
 Facultative organisms can switch the
metabolic pathways

Can grow with only little moisture
 A few dissolved minerals
 These bacteria are photosynthetic and
can convert CO2 from the atmosphere
into the organic compounds
 They can convert N2 to NH3

Organisms from extreme environments
are called extremophiles
 They provide the human race with
important tools for processes to make
useful chemicals and medicinals.
 Can be used in the recovery of metals
from low-grade ores or in the
desulfurization of coal or other fuels

Spherical (Coccus- cocci)
 Cylindrical (rod or bacillus-bacilli)
 Ellipsoidal (Coccus- cocci)
 Spiral (spirillum-spirilla)
 Pleomorphic cells

Procaryotes
 have a simple structure with a single
chromosome
 No nuclear membrane, no organelles,
such as mitochondria, endoplasmic
reticulum.

Eucaryotic cells
 have more than one chromosome (DNA
molecule) in the nucleus.
 have a true nuclear membrane
 contain mitochondria
 Endoplasmic reticulum
 Golgi apparatus
 a variety of specialized organelles

Eucaryotes
Eucaryotic
Plants, Animals, Protists (Algae, fungi,
protozoa)
Eubacteria
Procaryotic
Most bacteria

Archaebacteria
Procaryotic
Methanogens, halophiles,
thermoacidophiles
Gram-negative cell (E. coli) has an outer
membrane supported by a thin
peptidoglycan layer.
 Gram-positive cells (Bacillus subtilis)
do not have an outer membrane, have
a very thick, rigid cell wall with multiple
layers of peptidoglycan
Mycoplasma (not gram positive or gram
negative

Actinomycetes are bacteria, but,
morphologically, resemble molds.
 Cyanobacteria(blue-green algae) have
chlorophyll and fix CO2 into sugars.
 Anoxygenic photosynthetic
bacteria(purple and green bacteria)
have light-gathering pigments called
bacteriochlorophyll.

Ribosomes are the site of protein synthesis,
consists of 63% RNA and 37% protein.
 Storage granules are used as a source of
key metabolites and contain
polysaccharides, lipids, sulfur granules.
 Bacterial spores are produced as a
resistance of adverse conditions such as
high temperature, radiation, toxic
chemicals.
 Volutin is granular intracellular structure,
made of inorganic polymetaphosphates.

Archaebacteria have no peptidoglycan
 The nucleotide sequences in the
ribosomal RNA are similar within the
archaebacteria but different from
eubacteria
 The lipid composition of the cytoplasmic
membrane is very different for the two
groups.
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The nucleus of eucaryotic cells contains
chromosomes as nuclear material (DNA molecules
with associated small proteins), surrounded by a
membrane.
The nucleolus is the site of ribosome synthesis.
Many chromosomes contain small amounts of RNA
and basic proteins called histones attached to the
DNA.
Each chromosome contains a single linear DNA
molecule on which the histones are attached.
Mitochondria are the powerhouses of a
eucaryotic cell, where respiration and
oxidative phosphorylation take place.
 The mitochondria contain a complex
system of inner membranes called
cristae.
 A mitochondria has its own DNA and
protein-synthesizing machinery and
reproduces independently.

The endoplasmic reticulum is a complex,
convoluted membrane system leading
from the cell membrane into the cell.
 The rough endoplasmic reticulum
contains ribosomes and is the site of
protein synthesis and modifications of
protein structure after synthesis.
 The smooth endoplasmic reticulum is
involved with lipid synthesis.

Lysosomes are very small membranebound particles that contain and release
digestive enzymes.
 Peroxisomes carry out oxidative
reactions that produce hydrogen
peroxide.
 Glyoxysomes are very small membranebound particles that contain the
enzymes of the glyoxylate cycle.
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Golgi bodies are very small particles
composed of membrane aggregates and are
responsible for the secretion of certain proteins.
Vacuoles are membrane-bound organelles of
low density and are responsible for food
digestion, osmotic regulation, and wasteproduct storage.
Chloroplasts are relatively large, chlorophyllcontaining, green organelles that are
responsible for photosynthesis in photosynthetic
eucaryotes, such as algae and plant cells.
Pseudomonas sp. (bacterium)
 Geotrichum candidum (yeast)
 Mucor miehei (fungus)
 Rhizopus delemar (fungus)

 Michael L. Shuler and Fikret Kargı,
Bioprocess Engineering: Basic
Concepts (2 nd Edition),Prentice Hall,
New York, 2002.
 1. James E. Bailey and David F. Ollis,
Biochemical Engineering
Fundementals (2 nd Edition), McGrawHill, New York, 1986.