Microcystin Biosynthesis andmcyAExpression in Geographically DistinctMicrocystisStrains under Different Nitrogen, Phosphorus, and Boron Regimes.
Roles of nutrients and other environmental variables in development of cyanobacterial bloom and its toxicity are complex and not well understood. We have monitored the photoautotrophic growth, total microcystin concentration, and microcystins synthetase gene (mcyA) expression in lab-grown strains ofMicrocystisNIES 843 (reference strain), KW (Wangsong Reservoir, South Korea), and Durgakund (Varanasi, India) under different nutrient regimes (nitrogen, phosphorus, and boron). Higher level of nitrogen and boron resulted in increased growth (avg. 5 and 6.5 Chlamg/L, resp.), total microcystin concentrations (avg. 1.185 and 7.153 mg/L, resp.), andmcyAtranscript but its expression was not directly correlated with total microcystin concentrations in the target strains. Interestingly, Durgakund strain had much lower microcystin content and lacked microcystin-YR variant over NIES 843 and KW. It is inferred that microcystin concentration and its variants are strain specific. We have also examined the heterotrophic bacteria associated with cyanobacterial bloom in Durgakund Pond and Wangsong Reservoir which were found to be enriched in Alpha-, Beta-, and Gammaproteobacteria and that could influence the bloom dynamics.
Cell Factory Research Center, Korea Research Institute of Bioscience & Biotechnology, Daejeon, Republic of Korea.
Ankita
A
Srivastava
Cell Factory Research Center, Korea Research Institute of Bioscience & Biotechnology, Daejeon, Republic of Korea.
So-Ra
SR
Ko
Cell Factory Research Center, Korea Research Institute of Bioscience & Biotechnology, Daejeon, Republic of Korea.
Chi-Yong
CY
Ahn
Cell Factory Research Center, Korea Research Institute of Bioscience & Biotechnology, Daejeon, Republic of Korea.
Hee-Mock
0000-0002-2151-3687
HM
Oh
Ocular Biochemistry, Dr. R. P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi 110029, India.
Alok Kumar
AK
Ravi
Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi 221 005, India.
Ravi Kumar
0000-0002-3794-8810
RK
Asthana
D001426:Bacterial Proteins / Q000378:metabolism*; D001895:Boron / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D005843:Geography; D052998:Microcystins / Q000096:biosynthesis*; D046931:Microcystis / Q000145:classification / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism*; D010758:Phosphorus / Q000378:metabolism*; D013045:Species Specificity
D001426:Bacterial Proteins; D052998:Microcystins; D010758:Phosphorus; C078588:microcystin; D009584:Nitrogen; D001895:Boron