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Effects of Cylindrospermopsin Producing Cyanobacterium and Its Crude Extracts on a Benthic Green Alga-Competition or Allelopathy?

B-Béres V, Vasas G, Dobronoki D, Gonda S, Nagy SA, Bácsi I - Mar Drugs (2015)

Bottom Line: The growth inhibition of Chlorococcum sp. increased with the increasing ratio of the cyanobacterium in mixed cultures (inhibition ranged from 26% to 87% compared to control).Interestingly, inhibition of the cyanobacterium growth also occurred in mixed cultures, and it was more pronounced than it was expected.The inhibitory effects of cyanobacterial crude extracts on Chlorococcum cultures were concentration-dependent.

View Article: PubMed Central - PubMed

Affiliation: Environmental Laboratory, Department of Environment and Conservation, Hajdú-Bihar County Government Office, 16 Hatvan street, Debrecen H-4025, Hungary. beres.viktoria@gmail.com.

ABSTRACT
Cylindrospermopsin (CYN) is a toxic secondary metabolite produced by filamentous cyanobacteria which could work as an allelopathic substance, although its ecological role in cyanobacterial-algal assemblages is mostly unclear. The competition between the CYN-producing cyanobacterium Chrysosporum (Aphanizomenon) ovalisporum, and the benthic green alga Chlorococcum sp. was investigated in mixed cultures, and the effects of CYN-containing cyanobacterial crude extract on Chlorococcum sp. were tested by treatments with crude extracts containing total cell debris, and with cell debris free crude extracts, modelling the collapse of a cyanobacterial water bloom. The growth inhibition of Chlorococcum sp. increased with the increasing ratio of the cyanobacterium in mixed cultures (inhibition ranged from 26% to 87% compared to control). Interestingly, inhibition of the cyanobacterium growth also occurred in mixed cultures, and it was more pronounced than it was expected. The inhibitory effects of cyanobacterial crude extracts on Chlorococcum cultures were concentration-dependent. The presence of C. ovalisporum in mixed cultures did not cause significant differences in nutrient content compared to Chlorococcum control culture, so the growth inhibition of the green alga could be linked to the presence of CYN and/or other bioactive compounds.

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Changes of phosphate-concentration in mixed and control cultures (a) 0.2 × 106 cell·mL−1Chlorococcum sp. and 0.2 × 106 cell·mL−1C. ovalisporum; (b) 0.2 × 106 cell·mL−1Chlorococcum sp and 0.4 × 106 cell·mL−1C. ovalisporum; (c) 0.2 × 106 cell·mL−1Chlorococcum sp and 0.8 × 106 cell·mL−1C. ovalisporum. Significant differences are indicated with different lowercase letters.
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marinedrugs-13-06703-f003: Changes of phosphate-concentration in mixed and control cultures (a) 0.2 × 106 cell·mL−1Chlorococcum sp. and 0.2 × 106 cell·mL−1C. ovalisporum; (b) 0.2 × 106 cell·mL−1Chlorococcum sp and 0.4 × 106 cell·mL−1C. ovalisporum; (c) 0.2 × 106 cell·mL−1Chlorococcum sp and 0.8 × 106 cell·mL−1C. ovalisporum. Significant differences are indicated with different lowercase letters.

Mentions: Generally, phosphate-content decreased slower, i.e., phosphate-uptake was significantly lower (p < 0.05) in control cultures of C. ovalisporum than in the cases of the different mixed cultures (Figure 3). The cyanobacterium did not take up more than 50% of available phosphate in control cultures (Figure 3). In contrast, phosphate-uptake reached 90%–100% in the cases of green algal control culture and also in mixed cultures. Decrease of phosphate-content of green algal control culture and mixed cultures were not significantly different (Figure 3).


Effects of Cylindrospermopsin Producing Cyanobacterium and Its Crude Extracts on a Benthic Green Alga-Competition or Allelopathy?

B-Béres V, Vasas G, Dobronoki D, Gonda S, Nagy SA, Bácsi I - Mar Drugs (2015)

Changes of phosphate-concentration in mixed and control cultures (a) 0.2 × 106 cell·mL−1Chlorococcum sp. and 0.2 × 106 cell·mL−1C. ovalisporum; (b) 0.2 × 106 cell·mL−1Chlorococcum sp and 0.4 × 106 cell·mL−1C. ovalisporum; (c) 0.2 × 106 cell·mL−1Chlorococcum sp and 0.8 × 106 cell·mL−1C. ovalisporum. Significant differences are indicated with different lowercase letters.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4663549&req=5

marinedrugs-13-06703-f003: Changes of phosphate-concentration in mixed and control cultures (a) 0.2 × 106 cell·mL−1Chlorococcum sp. and 0.2 × 106 cell·mL−1C. ovalisporum; (b) 0.2 × 106 cell·mL−1Chlorococcum sp and 0.4 × 106 cell·mL−1C. ovalisporum; (c) 0.2 × 106 cell·mL−1Chlorococcum sp and 0.8 × 106 cell·mL−1C. ovalisporum. Significant differences are indicated with different lowercase letters.
Mentions: Generally, phosphate-content decreased slower, i.e., phosphate-uptake was significantly lower (p < 0.05) in control cultures of C. ovalisporum than in the cases of the different mixed cultures (Figure 3). The cyanobacterium did not take up more than 50% of available phosphate in control cultures (Figure 3). In contrast, phosphate-uptake reached 90%–100% in the cases of green algal control culture and also in mixed cultures. Decrease of phosphate-content of green algal control culture and mixed cultures were not significantly different (Figure 3).

Bottom Line: The growth inhibition of Chlorococcum sp. increased with the increasing ratio of the cyanobacterium in mixed cultures (inhibition ranged from 26% to 87% compared to control).Interestingly, inhibition of the cyanobacterium growth also occurred in mixed cultures, and it was more pronounced than it was expected.The inhibitory effects of cyanobacterial crude extracts on Chlorococcum cultures were concentration-dependent.

View Article: PubMed Central - PubMed

Affiliation: Environmental Laboratory, Department of Environment and Conservation, Hajdú-Bihar County Government Office, 16 Hatvan street, Debrecen H-4025, Hungary. beres.viktoria@gmail.com.

ABSTRACT
Cylindrospermopsin (CYN) is a toxic secondary metabolite produced by filamentous cyanobacteria which could work as an allelopathic substance, although its ecological role in cyanobacterial-algal assemblages is mostly unclear. The competition between the CYN-producing cyanobacterium Chrysosporum (Aphanizomenon) ovalisporum, and the benthic green alga Chlorococcum sp. was investigated in mixed cultures, and the effects of CYN-containing cyanobacterial crude extract on Chlorococcum sp. were tested by treatments with crude extracts containing total cell debris, and with cell debris free crude extracts, modelling the collapse of a cyanobacterial water bloom. The growth inhibition of Chlorococcum sp. increased with the increasing ratio of the cyanobacterium in mixed cultures (inhibition ranged from 26% to 87% compared to control). Interestingly, inhibition of the cyanobacterium growth also occurred in mixed cultures, and it was more pronounced than it was expected. The inhibitory effects of cyanobacterial crude extracts on Chlorococcum cultures were concentration-dependent. The presence of C. ovalisporum in mixed cultures did not cause significant differences in nutrient content compared to Chlorococcum control culture, so the growth inhibition of the green alga could be linked to the presence of CYN and/or other bioactive compounds.

Show MeSH
Related in: MedlinePlus