GROWTH ENHANCEMENT OF CYANOBACTERIA IN THE PRESENCE OF BACTERIA Karisma Dash Utkal niversity, PG department of Botany Abstract: In an ecosystem the relationship between cyanobacteria and bacteria provides some symbiotic and mutualistic factors which help to balance the ecosystem. The main objective of this research is to study the increase in growth of cyanobacteria/algae which is due to secretion of the growth enhancing factors by its associated bacterial partner. In this case the bacteria and cyanobacteria were co cultured to study the effect of bacteria on its associated cyanobacteria for their growth and other properties from which it was found that the growth and photosynthetic pigments are more in cyanobacterial bacterial co culture than that of the axenic culture. Further study showed that due to secretion of th vitamin B 12, IAA, Siderophore from the bacterial partner, the growth of cyanobacteria was increased up to 6 days of incubation. After the 16 S r RNA sequencing the bacteria and cyanobacteria were identified as Pseudomonas monteilii and Leptolyngbya lignicola respectively. This interaction study can be further used for microalgae harvesting, industrial uses, aquaculture by taking microbes as a biological agent rather than using expensive and harmful chemicals. OBJECTIVE: 1. Isolation, biochemical and phylogenetic characterization of algal/cyanobacterial and bacterial partners found in the association. 2. To study of the physiology of interaction under axenic and co culture condition in different treatments like different pH, different carbon source to find the effect of bacterial partner on growth. 3. To study the detection of growth reducing and growth promoting secondary metabolites produced by bacteria which affect the growth of algal partner. 4. To study the effect of cyanobacteria on growth of bacterial partner.
METHODOLOGY: • Isolation and purification of cyanobacteria and cyanobacteria associated bacteria in BG-11 and NA medium respectively. • Morphological and genetical characteristic of cyanobacteria and bacteria. • Dry weight of axenic cyanobacteria and its associated bacteria (Rai et al.,1991). • Growth promoting agent like IAA, vit B12, Siderophore estimation (E. Glickmann and Y. Dessaux, 1995). (Croft et al., 2005)
SEM of Leptolyngbya lignicola axenic
SEM of coculture condition
16S R rna sequencing of bacteria and cyanobacteria
0.02
0.015 L. lignicola 0.01 L. lignicola+ P. monteilli
Chlorophyll (µg/ml)
Dry Weight(mg/ml)
0.025 1.4
ABS 5.5
1.2
5.0
1
--- standard Vit B 12 ----L. lignicola + P. monteilli ----P. monteilli
4.5 4.0
0.8
3.5
0.6
3.0
L. lignicola
0.4
2.5 2.0
0.005 0.2
P. monteilli
L. lignicola+ P. monteilli
1.0
0
0 0
3
6
9
12
1.5
15
0.5
0
3
6
9
12
15 0.0 200
Days of incubation
250
300
350
400
450
500
550
nm 600
Days of incubation
Detection of Vit B 12
HPLC analysis for IAA detection
Siderophore detection
CONCLUSION In this study the cyanobacteria and its associated bacteria were identified as Leptolyngbya lignicola and Pseudomonas monteilli respectively where the associated bacteria helps in increasing cyanobacterial growth by the production of IAA, siderophore, Vit B12 etc. The positive effect of bacteria on cyanobacterial growth has enormous effect on industrial and biotechnological applications like algal cell harvesting , bio mass production etc. REFERENCES •Lindow, S.E., Dessourmont, C., Elkins, R., Mc Gourty, G., Clark E., and Brandi, M.T., 1998. Occurrence of indole -3- acetic acid producing bacteria on pear trees and their association with fruit Russet. Phytopathology. 88(11):1149–1156 •Eiler, A., and Bertilsson, S. (2004) Composition of freshwaterbacterial communities associated with cyanobacterialblooms in four Swedish lakes.Environ Microbiol6:1228–1243. •Ciferri, O. and Tiboni, O. (1985), The biochemistry and industrial potentials of Spirulina. Annu. Rev. Microbiol., 39: 503 – 526. •Pasternak JJ, Glick BR. 1996. Isolation and characterization of mutants of the plant growth-promoting rhizobacterium Pseudomonas putida GR12-2 that overproduce indoleacetic acid. •Croft, M.T., Lawrence, A.D., Raux-Deery, E., Warren, M.J., and Smith, A.G. (2005) Algae acquire vitamin B12 through a symbiotic relationship with bacteria. Nature 438: 90–93. •WatanabeK,Takihana N, AoyagiH,HanadaS,Watanabe Y, Ohmura N, Saiki H, Tanaka H (2005) Symbiotic association in Chlorella culture. FEMS Microbiol Ecol 51:187–196. ACKNOWLEDGEMENT The financial assistance provided by UGC [F.30-387/2017(BSR) dt. 09.03 2017], DST Govt. of Odisha and FIST are highly acknowledged.