This document provides information about green sulfur bacteria. It discusses their: 1. Scientific classification, which places them in the domain Bacteria, phylum Chlorobiota, class 'Chlorobia', and order chlorobiales. 2. Characteristics, including being gram-negative, rod or spherical shaped, and using light energy and reduced sulfur compounds for photosynthesis. 3. Habitat in aquatic environments like hot springs, stratified lakes, and marine habitats where they require anaerobic conditions and reduced sulfur.

1. SRI PARAMAKALYANI COLLEGE
( REACCREDITED WITH B GRADE WITH A CGPA OF 2.71 IN THE II CYCLE BY NAAC
AFFILIATED TO MANONMANIAM SUNDARANAR UNIVERSITY, TIRUNELVELI)
ALWARKURICHI 627 412 TAMIL NADU, INDIA
POST GRADUATE & RESEARCH CENTRE – DEPARTMENT OF MICROBIOLOGY
(GOVERNMENT AIDED)
II SEM – CORE - PHYSIOLOGY AND METABOLISM
Submitted by,
Kavitha. V
1st M. SC Microbiology
REG no: 20211232516112
Sri paramakalyani college of arts
and science,
Alwarkurichi
SUBMITTED TO ,
DR.S.VISWANATHAN PH.D.,
ASS.PROFF & HEAD OF MICROBIOLOGY
DEPARTMENT,
SRI PARAMAKALYANI COLLEGE,
ALWARKURICHI .

2. GREEN SULFUR
BACTERIA

3. SYNOPSIS
Introduction
Scientificclassification
Characteristics
Habitat
Nitrogen fixation
Photosynthesis process

4. Introduction
The green sulfur bacteria are a phylum
of obligately anaerobic photoautotrophic
bacteria that metabolize sulfur.
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5. 5
Scientificclassification
Domain: Bacteria (unranked) :Bacteroidota–
Chlorobiota group Phylum:Chlorobiota
Class :"Chlorobia"
Order :chlorobiales

6. 6
Characteristics
Green sulfur bacteria are gram-negative rod or sphericalal shaped bacteria. Some types of
green sulfur bacteria have gas vacuoles that allow for movement. They are
photolithoautotrophs, and use light energy and reduced sulfur compounds as the electron
source.[11] Electron donors include H2, H2S, S. The major photosynthetic pigment in these
bacteria is Bacteriochlorophylls c or d in green species and e in brown species, and is
located in the chlorosomes and plasma membranes.[12] Chlorosomes are a unique feature
that allow them to capture light in low-light conditions.[13]

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Habitat
The majority of green sulfur bacteria are mesophilic, preferring moderate
temperatures, and all live in aquatic environments. They require anaerobic
conditions and reduced sulfur; they are usually found in the top millimeters of
sediment. They are capable of photosynthesis in low light conditions.

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Where is green sulfur bacteria found?
They are found mostly in hot springs, often in mixed populations with
cyanobacteria. The sulfur bacteria are obligate photoautotrophs and
strict anaerobes that grow in dim light in sulfide-rich environments
such as effluents of sulfur springs and the lower layers of stratified
lakes and in marine habitats.

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How does green sulfur bacteria work?
Green sulfur bacteria perform a highly efficient photosynthesis due to the
presence of light harvesting organelles, the chlorosomes, which are filled
with special bacteriochlorophyll molecules. Green sulfur bacteria inhabit the
lowermost part of the photic environments due to their efficient light
capture.

10. Nitrogenfixation
Themajority ofgreensulfur bacteria are
diazotrophs: they canreduce nitrogento
ammoniawhich isthen used tosynthesize
aminoacids
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How do green sulfur bacteria carry out
photosynthesis?
Green sulfur bacteria perform a highly
efficient photosynthesis due to the presence
of light harvesting organelles, the
chlorosomes, which are filled with special
bacteriochlorophyll molecules. Green sulfur
bacteria inhabit the lowermost part of the
photic environments due to their efficient
light capture.

12. 12
photosynthetic electron transfer pathways in green sulfur bacteria

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Green sulfur bacteria and heliobacteria are strictly anaerobic phototrophs that have
homodimeric type 1 reaction center complexes. Within these complexes, highly reducing
substances are produced through an initial charge separation followed by electron
transfer reactions driven by light energy absorption. In order to attain efficient energy
conversion, it is important for the photooxidized reaction center to be rapidly rereduced.
Green sulfur bacteria utilize reduced inorganic sulfur compounds (sulfide, thiosulfate,
and/or sulfur) as electron sources for their anoxygenic photosynthetic growth.
Membrane-bound and soluble cytochromes c play essential roles in the supply of
electrons from sulfur oxidation pathways to the P840 reaction center. In the case of
gram-positive heliobacteria, the photooxidized P800 reaction center is rereduced by
cytochrome c-553 (PetJ) whose N-terminal cysteine residue is modified with fatty acid
chains anchored to the cytoplasmic membrane
photosynthetic electron transfer pathways in green sulfur bacteria

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Metaproteogenomic analysis of a dominant green sulfur bacterium

15. Chlorobium
tepidum,
15
Chlorobium
vibrioforme
Chloroherpeton
phaeobateriods
What is the example of Sulphur bacteria?

16. 16
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Release thresholds for moss spores: the importance of
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Reference

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20. Thank You!
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