This document presents information about bacterial cell inclusions. It defines cell inclusions as storage materials found within the cytoplasm of prokaryotic cells. The document then describes five main types of cell inclusions: 1) Metachromatic granules which are polyphosphate storage structures that take up dye differently, 2) Polysaccharide granules which store glycogen or starch, 3) Lipid inclusions which store lipids like polyhydroxybutyrate, 4) Sulfur granules found in sulfur-oxidizing bacteria, and 5) Carboxysomes which contain the enzyme RuBisCO for carbon dioxide fixation in photosynthetic bacteria.

1. BACTERIAL CELL
INCLUSIONS
PRESENTED BY :
A.DHEERAJ (BP211504),
DEPARTMENT OF MICROBIOLOGY,
SACRED HEART COLLEGE (AUTONOMOUS),
TIRUPATTUR.

2. CELL
INCLUSIONS
 Also known as Inclusions or Cell Inclusions or Inclusion bodies.
 Within the cytoplasm of prokaryotic cells, several kinds of reserve
deposits, known as Inclusions or Cell Inclusions
 It is the storage materials of energy, carbon, phosphorous and
other substances.
2 Cell inclusions March 29, 2022

3. TYPES OF CELL
INCLUSIONS
.
1. Metachromatic
Granules
.
3. Lipid 4. Sulphur
inclusions granules .
5.
Carboxysome
s
.
2. Polysaccharide
Granules
March 29, 2022
Annual Review
3

4. 1.Metachromatic granules
 Metachromatic granules are large inclusions that take their name from the fact that they
sometimes stain red with certain blue dyes such as Methylene blue (Metachromasia).
 Metachromatic Granules are made up of Polymetaphosphates and also called as Volutins or
Volutin Granules or Babe Ernst Granules or Polar Bodies.
 Volutin represents a reserve of Inorganic phosphate (polyphosphate) that can be used in
the synthesis of ATP. It is generally formed by cells that grow in phosphate - rich
environments.
 Metachromatic granules are present in Bacteria (Corynebacterium diphtheriae –
Causative agent of “Diphtheria”), Algae, Fungi and Protozoa.

.
.
.
4 Cell inclusions March 29, 2022

5. b) Polysaccharide Granules c) Lipid inclusions
 Polysaccharide granules typically
consist of Glycogen and Starch.
 In the presence of Iodine, Glycogen
granules appears in Red and Starch
granules appears in Blue.
• Lipid inclusions appear in various species
of Mycobacterium, Bacillus, Azotobacter,
Spirillum and other genera.
• A common lipid-storage material, one
unique to bacteria, is the polymer PHB
(Poly – β – hydrobybutyric acid).
• Lipid inclusions are revealed by staining
cells with fat-soluble dyes, such as Sudan
dyes

.
March 29, 2022
Annual Review
5

6. d) Sulfur Granules e) Carboxysomes
 Certain bacteria - the "Sulfur bacteria" that
belong to the genus Thiobacillus sp. derive
energy by oxidizing sulfur and sulfur-
containing compounds.
 The Sulfur bacteria may deposit sulfur
granules in the cell, where they serve as an
energy reserve.
 Carboxysomes are the bacterial Cell
inclusions that contain the enzyme
Ribulose 1,5 - diphosphate carboxylase.
 Photosynthetic bacteria use Carbon-di-
oxide as their sole source of carbon and
require this enzyme for Carbon-di-oxide
fixation.
 Carboxysomes containing bacteria are
Nitrifying bacteria, Cyanobacteria and
Thiobacilli.

.
•
.
March 29, 2022
Annual Review
6

7. Thank you
.
.