Chloroflexus and Spirulina

1. GROUP MEMBERS
NATIONAL UNIVERSITY OF SCIE & TECH
ZIMBABWE
Lazarus Mavima
Joseph Ndondo
Yeukai Muusha
Tatenda Marumbwa
Faith Ntokozo
Cain Kaundikiza
Irvine Mpofu

2. CHLOROFLEXUS
&
SPIRULINA

3. BACKGROUND
• Chloroflexus are genus of bacteria also called the green non
sulphur bacteria.
• They are classified as thermophiles.
• They are photosynthetic bacteria but differ from
cyanobacteria and eukaryotes in that…….

4. CHLOROFLEXUS SPP CONT…
 they are anoxygenic, do not have photosystem ll, hence
cannot use water as an eletron donor in noncyclic electron
transport
 they use electron donors such as hydrogen, hydrogen
sulphide, organic compoucnds
 they do not possess chlorophyll but possess slightly
different photosynthetic pigments or bacteriochlorophylls
i.e. bacteriochlorophyll a and c

5. • Chloroflexus spp. are gram negative filamentous
thermophilic bacteria
• often isolated from neutral to alkaline (pH 9) hot spring
• Chloroflexus show photosynthetic properties characteristic
of both purple bacteria and green bacteria.

6. • Chloroflexus is found at higher temperatures with an optimal
growth between 50 and 55oC
• Generally, Chloroflexus inhabit a number of environment
types such as hot springs, lakes, river water and sediments,
and in marine and hypersaline environments. Near hot
springs, especially.
• Freshwater lakes also contain Chloroflexus-like organisms

7. • Some strains of Chloroflexus can also grow alone in springs
high in sulfide, which it uses as an electron donor
• Sulphur produced by sulphide oxidation is deposited
extracellularly.
• an example of such bacterium is Chloroflexus aurantiacus

8. ENVIRONMENTS WHERE ANAEROBIC
THERMOPHILES CAN BE ISOLATED
Terrestrial hot springs at Viterbo Italy (Left) & The hot pool of
Bagno Vignoni, Italy.

9. • Chloroflexus can be found in the lower layers of microbial
mats with cyanobacteria growing above it.
• It seems to use the organic products of the cyanobacteria;
however,
• some strains Chloroflexus can also grow alone in springs
high in sulfide, which it uses as an electron donor (it can
also use hydrogen).

10. CELL STRUCTURE AND METABOLISM
• Chloroflexus is a, filamentous, gliding bacterium found in
the green non-sulfur branch in the 16s rRNA tree of life.
• They lack internal membranes unlike unlike purple
bacteria
• Generally, Chloroflexus is a photoheterotroph and uses
organic molecules that are made from other bacteria, but
some Chloroflexus strains grow autotrophically and use
hydrogen or sulfide as an electron donor.

12. NUTRITION AND METABOLISM
• Chloroflexus shares with green bacteria the ability to grow
photoautotrophically using sulfide as electron donor
• it does so employing a unique pathway for autotrophic CO2
fixation, the hydroxypropionate pathway. This pathway is
absent from all other anoxygenic phototrophic bacteria.

13. • Chloroflexus aurantiacus fix CO2 differently from other
phototrophs through a pathway called the 3-
hydroxypropionate pathway
• They seem to lack ribulose bisphosphate carboxylase
activity

14. • In anaerobic (or semiaerobic) situations, Chloroflexus
aurantiacus harvests light in chlorosomes that are slightly
smaller than those of green sulfur bacteria. Also like purple
bacteria, Chloroflexus bacteria have pheophytin-quione type
photochemical reaction centers. (Sprague et al. 1981)
• Aerobically chloroflexus aurantiacus do not produce
bacteriochlorophylls and grows chemotrophically

15. SPIRULINA SP.
• Spirulina were initially thought to be eukaryotes (a
type of fungi)
• However, phylogenetic and morphological analysis
illustrated them to be bacteria.
• Many genera of cyanobacteria are harmful to
humans. Spirulina, however, are unique not only in
that they are edible, but also because they provide
many health benefits.

16. • Spirulina are Gram-negative, microbes that are
undifferentiated and filamentous.
• Spirulina can be rod shaped bacilli or disk-shaped.
• Their main photosynthetic pigment is phycocyanin,
which is blue in color, along with chlorophyll a and
carotenoids.
• Some contain the pigment phycoythrin, giving the
bacteria a red or pink color.
• Spirulina have gas vesicles, giving them bouyancy in
the aquatic environments they inhabit. Spirulina are
photosynthetic, and therefore autotrophic bacteria
that reproduce by binary fission.

17. • Spirlulina are aquatic organisms, typically inhabiting
freshwater alkaline lakes and marine bodies.
• They are mesophilic, and able to survive over a wide
range of temperatures
• Spriulina is an edible bacteria. Flamingos get their pink
color from eating Spirulina that contain phycoythrin .
• It is also used in Asian cusine. In America, Spirulina is sold
in health food stores as a powder or tablet (Spirulina are
an excellent source of both protein and iron).

18. • Its carotenoids absorb radiation.
• Evidence shows that it is capable of stopping viral
replication. It prevents the virus from penetrating a
cell wall and infecting the cell.
• This bacteria also slows neurological damage in aging
animals, and it can lessen the damage caused by
stroke.
• Studies also show that Spirulina can prevent the
release of histamines, treating allergy symptoms.
• Spriulina has nonmedical uses as well. A study by
Chen and Pan (2005) shows that the bacteria can
remove low concentrations of lead from wastewater