Growth, microcystin-production and proteomic responses of Microcystis aeruginosa under long-term exposure to amoxicillin

2016 ◽  
Vol 93 ◽  
pp. 141-152 ◽  
Author(s):  
Ying Liu ◽  
Shi Chen ◽  
Jian Zhang ◽  
Baoyu Gao
Keyword(s):  
Microcystis Aeruginosa ◽  
Microcystin Production ◽  
Proteomic Responses

scholarly journals Physiological and Proteomic Responses of Continuous Cultures of Microcystis aeruginosa PCC 7806 to Changes in Iron Bioavailability and Growth Rate

2016 ◽  
Vol 82 (19) ◽  
pp. 5918-5929 ◽  
Author(s):  
Anna C. Y. Yeung ◽  
Paul M. D'Agostino ◽  
Anne Poljak ◽  
James McDonald ◽  
Mark W. Bligh ◽  
...  
Keyword(s):  
Microcystis Aeruginosa ◽  
Public Health Problem ◽  
Iron Bioavailability ◽  
Iron Limitation ◽  
Global Public Health ◽  
Continuous Cultures ◽  
Content Type ◽  
Cyanobacterial Species ◽  
Microcystin Production ◽  
Proteomic Responses

ABSTRACTThe hepatotoxin microcystin (MCYST) is produced by a variety of freshwater cyanobacterial species, includingMicrocystis aeruginosa. Interestingly, MCYST-producingM. aeruginosastrains have been shown to outcompete their nontoxic counterparts under iron-limiting conditions. However, the reasons for this are unclear. Here we examined the proteomic response ofM. aeruginosaPCC 7806 continuous cultures under different iron and growth regimes. Iron limitation was correlated with a global reduction in levels of proteins associated with energy metabolism and photosynthesis. These proteomic changes were consistent with physiological observations, including reduced chlorophyllacontent and reduced cell size. While levels of MCYST biosynthesis proteins did not fluctuate during the study period, both intra- and extracellular toxin quotas were significantly higher under iron-limiting conditions. Our results support the hypothesis that intracellular MCYST plays a role in protecting the cell against oxidative stress. Further, we propose that extracellular MCYST may act as a signaling molecule, stimulating MCYST production under conditions of iron limitation and enhancing the fitness of bloom populations.IMPORTANCEMicrocystin production in water supply reservoirs is a global public health problem. Understanding the ecophysiology of hepatotoxic cyanobacteria, including their responses to the presence of key micronutrient metals such as iron, is central to managing harmful blooms. To our knowledge, this was the first study to examine proteomic and physiological changes occurring inM. aeruginosacontinuous cultures under conditions of iron limitation at different growth rates.

Influence of increased nutrient supply on Microcystis aeruginosa at cellular and proteomic levels

2020 ◽  
Vol 85 ◽  
pp. 47-58
Author(s):  
Y Jiang ◽  
Y Liu
Keyword(s):  
Microcystis Aeruginosa ◽  
Regulatory Protein ◽  
Acid Synthesis ◽  
Nutrient Supply ◽  
Nitrogen Supply ◽  
Nitrogen And Phosphorus ◽  
Comprehensive Description ◽  
Amino Acid Synthesis ◽  
High Nutrient ◽  
Proteomic Responses

Various studies have observed that increased nutrient supply promotes the growth of bloom-forming cyanobacteria, but only a limited number of studies have investigated the influence of increased nutrient supply on bloom-forming cyanobacteria at the proteomic level. We investigated the cellular and proteomic responses of Microcystis aeruginosa to elevated nitrogen and phosphorus supply. Increased supply of both nutrients significantly promoted the growth of M. aeruginosa and the synthesis of chlorophyll a, protein, and microcystins. The release of microcystins and the synthesis of polysaccharides negatively correlated with the growth of M. aeruginosa under high nutrient levels. Overexpressed proteins related to photosynthesis, and amino acid synthesis, were responsible for the stimulatory effects of increased nutrient supply in M. aeruginosa. Increased nitrogen supply directly promoted cyanobacterial growth by inducing the overexpression of the cell division regulatory protein FtsZ. NtcA, that regulates gene transcription related to both nitrogen assimilation and microcystin synthesis, was overexpressed under the high nitrogen condition, which consequently induced overexpression of 2 microcystin synthetases (McyC and McyF) and promoted microcystin synthesis. Elevated nitrogen supply induced the overexpression of proteins involved in gas vesicle organization (GvpC and GvpW), which may increase the buoyancy of M. aeruginosa. Increased phosphorus level indirectly affected growth and the synthesis of cellular substances in M. aeruginosa through the mediation of differentially expressed proteins related to carbon and phosphorus metabolism. This study provides a comprehensive description of changes in the proteome of M. aeruginosa in response to an increased supply of 2 key nutrients.

The combined effects of Dolichospermum flos-aquae, light, and temperature on microcystin production by Microcystis aeruginosa

2016 ◽  
Vol 34 (6) ◽  
pp. 1173-1182 ◽  
Author(s):  
Ruoqi Chen ◽  
Fangfang Li ◽  
Jiadong Liu ◽  
Hongye Zheng ◽  
Fei Shen ◽  
...  
Keyword(s):  
Microcystis Aeruginosa ◽  
Combined Effects ◽  
Microcystin Production

Diurnal mixed layers and the long-term dominance of Microcystis aeruginosa

1989 ◽  
Vol 11 (1) ◽  
pp. 25-48 ◽  
Author(s):  
Tamar Zohary ◽  
Richard D. Robarts
Keyword(s):  
Microcystis Aeruginosa ◽  
Mixed Layers

scholarly journals Microcystin Production by Microcystis aeruginosa in a Phosphorus-Limited Chemostat

2000 ◽  
Vol 66 (1) ◽  
pp. 176-179 ◽  
Author(s):  
Hee-Mock Oh ◽  
Seog June Lee ◽  
Min-Ho Jang ◽  
Byung-Dae Yoon
Keyword(s):  
Microcystis Aeruginosa ◽  
High Performance ◽  
Specific Growth ◽  
Dry Weight ◽  
Atomic Ratio ◽  
Uv Detector ◽  
Fixation Rate ◽  
P Limitation ◽  
P Content ◽  
Microcystin Production

ABSTRACT The production of microcystins (MC) from Microcystis aeruginosa UTEX 2388 was investigated in a P-limited continuous culture. MC (MC-LR, MC-RR, and MC-YR) from lyophilized M. aeruginosa were extracted with 5% acetic acid, purified by a Sep-Pak C18 cartridge, and then analyzed by high-performance liquid chromatography with a UV detector and Nucleosil C18 reverse-phase column. The specific growth rate (μ) ofM. aeruginosa was within the range of 0.1 to 0.8/day and was a function of the cellular P content under a P limitation. The N/P atomic ratio of steady-state cells in a P-limited medium varied from 24 to 15 with an increasing μ. The MC-LR and MC-RR contents on a dry weight basis were highest at μ of 0.1/day at 339 and 774 μg g−1, respectively, while MC-YR was not detected. The MC content of M. aeruginosa was higher at a lower μ, whereas the MC-producing rate was linearly proportional to μ. The C fixation rate at an ambient irradiance (160 microeinsteins m−2s−1) increased with μ. The ratios of the MC-producing rate to the C fixation rate were higher at a lower μ. Accordingly, the growth of M. aeruginosa was reduced under a P limitation due to a low C fixation rate, whereas the MC content was higher. Consequently, increases in the MC content per dry weight along with the production of the more toxic form, MC-LR, were observed under more P-limited conditions.

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