Siderophores are compounds from ancient Greek words, sidero ‘iron’ and phore ‘carriers’ meaning ‘iron carriers’. These are low-molecular-weight iron-chelating compounds, produced by ‘rhizospheric bacteria’ under iron-limited conditions. They are small, high affinity iron chelating compounds secreted by microorganisms such as bacteria, fungi etc. Siderophore usually form a stable hexahendate, octahedral complex with Fe3+.
3. What is siderophore ?
Role and Importance of siderophore
How siderophore will form?
Mechanism of siderophore
Method use for determination of siderophore.
Effect of siderophore on morphological character, yield and
uptake of nutrient by crop
4. Siderophores are compounds from ancient Greek words, sidero
‘iron’ and phore ‘carriers’ meaning ‘iron carriers’.
These are low-molecular-weight iron-chelating compounds,
produced by ‘rhizospheric bacteria’ under iron-limited conditions.
They are small, high affinity iron chelating compounds secreted by
microorganisms such as bacteria, fungi etc.
Siderophore usually form a stable hexahendate, octahedral
complex with Fe3+
Kloepper et al.(1980) were the first to demonstrate the importance
of Siderophores.
5. Iron is a constituent of protein.
It activates the number of enzymes.
Iron is a vital element require by all living organisms for many
cellular processes such as electron transport chain and as a
cofactor for many enzymes
It plays an essential role in the nucleic acid metabolism.
It is necessary for synthesis and maintenance of chlorophyll in
plants.
IRON – AN IMPORTANT ESSENTIAL ELEMENT
8. HOW SIDEROPHORES WILL FORM???
Iron is often
insoluble
(oxides,
hydroxides)
Cells produce
siderophores
Iron binds to
siderophore
complex
Siderophore
binds to
recognition site
on cell
Iron is reduced
(Fe3+
into Fe )2+
Iron is taken up
by the cell.
13. Widely used method for detection of siderophore
production by microorganisms in solid medium is
the universal Chrome azurol S (CAS) agar plate
assay.
DETECTION OF SIDEROPHORE PRODUCTION
Source: Schwyn, B., and J. B. Neilands.(1987) .Analytical Biochem.3(3):47-56.
18. Effect of pH on Siderophore production.
Source: Ali S.S. & Vidhale N.N(2011), International Journal of Microbiology Research 3(3), 131.
19. Organisms
Shoot
length(cm)
Root
length(cm)
Germination
(Days)
Control - 6.2±0.2 4.5±0.19 6±0.11
Test P. fluorescens 12.5±0.12 8.5±0.63 4±0.24
P. aeruginosa 11.5±0.26 7.9±0.39 4±0.18
Organisms Shoot
length(cm)
Root
length(cm)
Germination
(Days)
Control - 6.1±0.23 3.5±0.17 7±0.37
Test P. fluorescens 10.0±0.62 5.1±0.27 5±0.33
P. aeruginosa 9.6±0.49 4.8±0.19 7±0.21
Table 2 : Influence of Pseudomonas sp. inoculation on seed
germination and growth of Triticum aestivum
Table no. 3 : Influence of Pseudomonas sp. inoculation on seed
germination and growth of Apios americana (Potato bean)
Source: Bholay. et al.,(2012)IOSR Journal of pharmacy and Biology Science Vol (3),pp 27-32
20. Source: Bholay. et al.,(2012)IOSR Journal of pharmacy and Biology Science Vol 3,pp 27-32
Graphical Representation of Table 2 and Table 3
21. Isolates
CAS assay( halo formation in
blue agar)
Diameter of halo(in
cm)
1 + 1.50±0.2
2 + 1.40±0.1
3 - -
4 + 0.78±0.2
5 + 1.30±0.3
6 + 0.60±0.4
7 + 0.80±0.1
8 - -
9 + 0.90±0.4
10 - -
11 + 1.10±0.5
12 + 1.30±0.1
R. meliloti + 1.70±0.3
Table 4: Growth of siderophore on CAS agar plate
Source: Verma V., et al.,(2012) Research Journal of Chemical Science Vol (3),pp 27-32
22. Treatment
Root length Shoot length
% seed
germination
Initial
(mm)
Increased
in mm
Initial
(mm)
Increased
in mm
Control 35.0 - 30.7 - 30
Test 42.0 7 70.9 40.2 50
Table 5: Influence of Bacillus shakletonii GN-09 inoculation
on Soybean growth
Source: Jikare A.M. & Chavan M.D. (2013) International Journal of Research and Biological
Science Vol 3, 198-202
23. Organism Pot culture
P.
Pseudoal
aligenes
Fe Cu Mn Zn Co Ni Al
P-
31.2±0.
0001
0.28±0.0
001
0.38±0.0
006
0.52±0.0
024
0.35±0.0
015
0.42±0.0
001
0.97±0.0
001
P+
69.8±0.
0001
1.20±0.0
001
9.60±0.0
001
0.93±0.0
014
0.36±0.0
004
0.55±0.0
025
10.72±0.
0002
Table 6: Effect of with and without Siderophore producing
microbes on the microelement uptake in root of Cajanas
cajan in pot studies.
Source : Gamit D.A. & Tank S.K.,(2014) International Journal of Research in Pure and
Applied Microbiology .4(1), 20-27.
24. Table 7: Effect of with and without Siderophore producing
microbes on the microelement uptake in shoot of
Cajanas cajan in pot studies.
Organi
sm
Pot culture
P.
pseudo
alcalig
enes
Fe Cu Mn Zn Co Ni Al
P-
57.6±0.0
001
0.54±0.0
003
2.31±0.0
009
0.69±0.0
033
0.26±0.0
018
0.30±0.0
010
1.09±0.0
001
P+
123.9±0.
0003
0.98±0.0
003
9.99±0.0
030
1.55±0.0
019
0.67±0.0
021
0.76±0.0
020
25.6±0.0
002
Source : Gamit D.A. & Tank S.K.,(2014) International Journal of Research in Pure and
Applied Microbiology .4(1), 20-27.
25. Shoot length(cm) Root length(cm) Number of leaves(cm)
Control 7 1.5 13
Iron deprived
condition
5 3 10
Iron deprived and
siderophore
supplemented
condition
9 5 19
Shoot
length(cm)
Root length(cm)
Number of
leaves(cm)
Control 15 4.5 9
Iron deprived condition 10 3 6
Iron deprived and
siderophore
supplemented condition
17.5 6.5 13
Table 8: Effect of siderophore produce by Pseudomonas flurescens on the
growth of Masoor dal
Table no. 9: Effect of siderophore produce by Pseudomonas flurescens on the
growth of large white lima bean
Source:Parmar H.Y.& Chakraborty H. (2016) International Journal of Recent
Scientific Research Vol (3) 101-107
26. Fig: Effect of Siderophore on growth of Lens culinaris
(Masoor Dal)
Source: Parmar H.Y.and Chakraborty H. (2016) International Journal of
Recent Scientific Research Vol (3) 101-107
27. No Given Bacterial isolates Root length Shoot length Vigor index Germination%
C Control 5.6 3.1 609 70%
M1R2
Pseudomonas
spp.
9.6 5.2 1480 100%
M7R1
Pseudomonas
spp.
4.2 5.5 582 60%
M6S3
Enterobacter
spp.
5.4 6.6 840 70%
M7S1
Stenotrophomon
as spp
9.0 5.2 1420 100%
M7ER1
Microbacterium
spp.
9.9 5.3 1292 85%
M7ER2
Microbacterium
spp.
6.0 3.1 728 80%
M12R2 Bacillus spp. 7.8 6.2 1120 80%
M12R1 Bacillus spp. 10.6 3.5 930.6 66%
Table no 10: Influence of bacterial isolates inoculation on sunflower
germination and growth in plate experiment
Source: Raval A.A.& Desai P.B.(2015) International
Journal of Pharmacy and Life Sciences Vol(6)
pp 4803 4811
28. Microorganisms
Nodules per plant
Nitrogenase
activity
Dry weight
(mg per plant)
Total nitrogen
(mg per plant)
No.
Fresh
weight(mg)
µmolC2H4
plant-1h-1
Shoot Root Shoot Root
Bradyrhizobium
USDA 3447
90 480 7.5 1110 512 55 14
Bradyrhizobium
USDA 3447+
Pseudomonas
aeruginosa
150 810 10.2 1600 780 85 25
Bradyrhizobium
USDA
3447+P.chrysogenum 173 920 12.4 1815 870 102 29
LSD(P=5%) 20 105 1.8 196 95 19 10
Table no 11 : Effect of siderophore producing organisms on
nodulation, nitrogenase activity and plant growth of mung bean
Source: Mahmoud A.L. & Abd-alla .M.H (2001) International Journal of
Agriculture and Biology, Vol (3), 157-162.
29. Iron is essential for almost all life, essential for processes such as respiration
and DNA synthesis.
Siderophore production by different microorganisms were confirmed by
Universal CAS assay. The colour change of CAS from blue to oranged-red
resulted from siderophore removal of Fe from dye . Amount of siderophore
produced were estimated as percentage of siderophore units as the proportion of
CAS colour shifted.
Under aerated conditions at neutral to alkaline pH, inorganic iron is extremely
insoluble for bacterial growth. To acquire iron bacterial cell produce
siderophore.There is an enormous scope for the application of microbial
siderophores for sustanibility of agriculture and environment
CONCLUSION
30. Siderophore which was proved to be useful for plant growth promotion due to
increased in root length, shoot length,when grown under iron limiting condition
with siderophore supplements.
Siderophore producing microbes stimulated the nodulation, nitrogen fixation
and plant growth of many crop. Thus, siderophore can be used in combination
with other biofertilizers to increase crop productivity