The combined effect of clethodim (herbicide) and nitrogen variation on allelopathic interactions between Microcystis aeruginosa and Raphidiopsis raciborskii

2020 ◽  
Author(s):  
Fernanda Brêda-Alves ◽  
Valéria de Oliveira Fernandes ◽  
Micheline Kézia Cordeiro-Araújo ◽  
Mathias Ahii Chia
Keyword(s):  
Microcystis Aeruginosa ◽  
Combined Effect ◽  
Allelopathic Interactions

scholarly journals Allelopathic interactions of linoleic acid and nitric oxide increase the competitive ability of Microcystis aeruginosa

2017 ◽  
Vol 11 (8) ◽  
pp. 1865-1876 ◽  
Author(s):  
Hao Song ◽  
Michel Lavoie ◽  
Xiaoji Fan ◽  
Hana Tan ◽  
Guangfu Liu ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Linoleic Acid ◽  
Microcystis Aeruginosa ◽  
Competitive Ability ◽  
Allelopathic Interactions

scholarly journals Competitive dominance of Microcystis aeruginosa against Raphidiopsis raciborskii is strain- and temperature-dependent

2020 ◽  
pp. 36
Author(s):  
Lamei Lei ◽  
Jingjun Dai ◽  
Qiuqi Lin ◽  
Liang Peng
Keyword(s):  
Microcystis Aeruginosa ◽  
Competitive Ability ◽  
Competitive Exclusion ◽  
Strain Difference ◽  
Freshwater Ecosystems ◽  
Cylindrospermopsis Raciborskii ◽  
Temperature Dependent ◽  
Temperature Levels ◽  
Multiple Strains ◽  
Allelopathic Interactions

Microcystis aeruginosa and Raphidiopsis raciborskii (previously Cylindrospermopsis raciborskii) are both common bloom-forming cyanobacteria which can coexist but alternatively dominate in freshwater ecosystems. To predict their blooming dynamics, we need to understand the potential environmental factors determining their succession. In the present study, we examined the pairwise competition of the three M. aeruginosa strains (FACHB905, 469 and 915) with one R. raciborskii strain (N8) at three temperature levels (16 °C, 24 °C, and 32 °C). We found that the competitive ability of three Microcystis strains were highly variable. M. aeruginosa FACHB905 was the strongest competitor among them which can finally exclude R. raciborskii N8 regardless of initial biovolume ratios and temperature levels. The competitive exclusion of N8 by 915 also was observed at 24 °C, but they coexisted at 16 °C and 32 °C. We observed that M. aeruginosa FACHB469 and R. raciborskii N8 were able to coexist under all the temperature levels, and M. aeruginosa FACHB469 was the weakest competitor among the three M. aeruginosa strains. Rates of competitive exclusion (RCE) showed that temperature affects the competition between three M. aeruginosa strains and R. raciborskii N8. M. aeruginosa strains always grew quickly at 24 °C and significantly enlarged its dominance in the co-culture system, while R. raciborskii N8 was able to maintain its initial advantages at both 16 and 32 °C. The competitive advantage of M. aeruginosa FACHB905 may be explained by allelopathic interactions through its allelochemicals and other secondary metabolites other than microcystin. We concluded that both strain difference and temperature can affect the competition between M. aeruginosa and R. raciborskii. Our results highlighted the complexity of cyanobacterial dynamics in waterbodies where there exist multiple strains.

scholarly journals Production of Cyanotoxins by Microcystis aeruginosa Mediates Interactions with the Mixotrophic Flagellate Cryptomonas

Toxins ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 223 ◽  
Author(s):  
Sarah DeVaul Princiotta ◽  
Susan P. Hendricks ◽  
David S. White
Keyword(s):  
Food Web ◽  
Microcystis Aeruginosa ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Secondary Compounds ◽  
Toxin Production ◽  
Nutritional Supplement ◽  
Trophic Levels ◽  
Negative Effects ◽  
Allelopathic Interactions

Eutrophication of inland waters is expected to increase the frequency and severity of harmful algal blooms (HABs). Toxin-production associated with HABs has negative effects on human health and aquatic ecosystem functioning. Despite evidence that flagellates can ingest toxin-producing cyanobacteria, interactions between members of the microbial loop are underestimated in our understanding of the food web and algal bloom dynamics. Physical and allelopathic interactions between a mixotrophic flagellate (Cryptomonas sp.) and two strains of a cyanobacteria (Microcystis aeruginosa) were investigated in a full-factorial experiment in culture. The maximum population growth rate of the mixotroph (0.25 day−1) occurred during incubation with filtrate from toxic M. aeruginosa. Cryptomonas was able to ingest toxic and non-toxic M. aeruginosa at maximal rates of 0.5 and 0.3 cells day−1, respectively. The results establish that although Cryptomonas does not derive benefits from co-incubation with M. aeruginosa, it may obtain nutritional supplement from filtrate. We also provide evidence of a reduction in cyanotoxin concentration (microcystin-LR) when toxic M. aeruginosa is incubated with the mixotroph. Our work has implications for “trophic upgrading” within the microbial food web, where cyanobacterivory by nanoflagellates may improve food quality for higher trophic levels and detoxify secondary compounds.

238: Combined Effect of Apoptotic Biomarkers on Bladder Cancer Recurrence and Mortality after Radical Cystectomy

2007 ◽  
Vol 177 (4S) ◽  
pp. 79-80
Author(s):  
Jose A. Karam ◽  
Yair Lotan ◽  
Raheela Ashfaq ◽  
Claus G. Roehrborn ◽  
Arthur I. Sagalowsky ◽  
...  
Keyword(s):  
Bladder Cancer ◽  
Radical Cystectomy ◽  
Cancer Recurrence ◽  
Combined Effect ◽  
Bladder Cancer Recurrence

Combined Effect of Doxorubicin with MODEL26 peptide

Planta Medica ◽  
2008 ◽  
Vol 74 (09) ◽  
Author(s):  
WG Shin ◽  
BJ Lee
Keyword(s):  
Combined Effect

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.

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