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Temperature Effect on Exploitation and Interference Competition among Microcystis aeruginosa, Planktothrix agardhii and, Cyclotella meneghiniana.

Gomes AM, de Oliveira e Azevedo SM, Lürling M - ScientificWorldJournal (2015)

Bottom Line: The temperature did not influence exploitation competition between MIJAC and other competitors and it was the best competitor in both temperatures.The growth of MIJAC was favored in strains exudates at 30°C, while CCAP was favored at 18°C, revealing that the optimum growth temperature was important to establish the competitive superiority.Therefore, we can propose two hypotheses: (i) different temperatures may results in production of distinct compounds that influence the competition among phytoplankton species and (ii) the target species may have different vulnerability to these compounds depending on the temperature.

View Article: PubMed Central - PubMed

Affiliation: Laboratório de Ecofisiologia e Toxicologia de Cianobactérias, IBCCF, Universidade Federal do Rio de Janeiro, CCS, Bloco G, 21949-900 Rio de Janeiro, RJ, Brazil ; Laboratório de Botânica, Instituto de Recursos Naturais, Universidade Federal de Itajubá, Avenida BPS 1303, Pinheirinho, 37500-903 Itajubá, MG, Brazil.

ABSTRACT
We studied the effect of temperature (18 and 30°C) on growth and on the exploitation and interference competition of three species: Microcystis aeruginosa (MIJAC), Planktothrix agardhii (PAT), and Cyclotella meneghiniana (CCAP). Coculturing the organisms in batch systems allowed for the examination of both competitive interactions, while the interference competition was studied in cross-cultures. The experiments were done during 10-12 days, and samples were taken for chlorophyll-a analysis, using PHYTO-PAM. The temperature did not influence exploitation competition between MIJAC and other competitors and it was the best competitor in both temperatures. PAT presented higher growth rates than CCAP in competition at 18 and 30°C. The temperature influenced the interference competition. The growth of MIJAC was favored in strains exudates at 30°C, while CCAP was favored at 18°C, revealing that the optimum growth temperature was important to establish the competitive superiority. Therefore, we can propose two hypotheses: (i) different temperatures may results in production of distinct compounds that influence the competition among phytoplankton species and (ii) the target species may have different vulnerability to these compounds depending on the temperature. At last, we suggest that both the sensitivity and the physiological status of competing species can determine their lasting coexistence.

No MeSH data available.


Chlorophyll-a-based growth rate of M. aeruginosa (a), P. agardhii (b), and C. meneghiniana (c) cultured at different temperatures. Different letters represent significant differences at p < 0.05.
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fig2: Chlorophyll-a-based growth rate of M. aeruginosa (a), P. agardhii (b), and C. meneghiniana (c) cultured at different temperatures. Different letters represent significant differences at p < 0.05.

Mentions: The reasons for seasonal variability in the phytoplankton composition are poorly understood but may include exploitation and interference competition. Collectively, our results suggest that the temperature can affect the growth, exploitation, and interference competition, but the response is dependent on the species. M. aeruginosa was the strongest competitor in all tested conditions. Temperature was not an important factor in M. aeruginosa growth in monocultures. Similar growth rates were observed for M. aeruginosa grown from 18°C to 30°C (Figure 2(a)). Possibly, even lower temperatures could affect the growth rate of this species, as Soares [23] described for M. aeruginosa growing at 12°C. High temperatures also did not increase its growth rate, although some authors have reported that the optimum growth temperature for M. aeruginosa is between 25 and 30°C [1, 24, 25]. On the other hand, P. agardhii growth was favored at higher temperatures and our results do corroborate those of Lürling et al. [25], showing that the optimum growth temperature for P. agardhii is around 27°C (Figure 2(b)). The variation of the C. meneghiniana growth rate in response to temperature is in agreement with the observations found for diatom species. Its growth was favored at lower temperatures (18°C and 21°C; Figure 2(c)). When we observe its distribution in water bodies, actually diatoms dominate the phytoplankton community at lower water temperatures [3, 26]. It is also interesting to observe that in these experimental conditions the highest growth rate among three tested strains was registered for C. meneghiniana.


Temperature Effect on Exploitation and Interference Competition among Microcystis aeruginosa, Planktothrix agardhii and, Cyclotella meneghiniana.

Gomes AM, de Oliveira e Azevedo SM, Lürling M - ScientificWorldJournal (2015)

Chlorophyll-a-based growth rate of M. aeruginosa (a), P. agardhii (b), and C. meneghiniana (c) cultured at different temperatures. Different letters represent significant differences at p < 0.05.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4561989&req=5

fig2: Chlorophyll-a-based growth rate of M. aeruginosa (a), P. agardhii (b), and C. meneghiniana (c) cultured at different temperatures. Different letters represent significant differences at p < 0.05.
Mentions: The reasons for seasonal variability in the phytoplankton composition are poorly understood but may include exploitation and interference competition. Collectively, our results suggest that the temperature can affect the growth, exploitation, and interference competition, but the response is dependent on the species. M. aeruginosa was the strongest competitor in all tested conditions. Temperature was not an important factor in M. aeruginosa growth in monocultures. Similar growth rates were observed for M. aeruginosa grown from 18°C to 30°C (Figure 2(a)). Possibly, even lower temperatures could affect the growth rate of this species, as Soares [23] described for M. aeruginosa growing at 12°C. High temperatures also did not increase its growth rate, although some authors have reported that the optimum growth temperature for M. aeruginosa is between 25 and 30°C [1, 24, 25]. On the other hand, P. agardhii growth was favored at higher temperatures and our results do corroborate those of Lürling et al. [25], showing that the optimum growth temperature for P. agardhii is around 27°C (Figure 2(b)). The variation of the C. meneghiniana growth rate in response to temperature is in agreement with the observations found for diatom species. Its growth was favored at lower temperatures (18°C and 21°C; Figure 2(c)). When we observe its distribution in water bodies, actually diatoms dominate the phytoplankton community at lower water temperatures [3, 26]. It is also interesting to observe that in these experimental conditions the highest growth rate among three tested strains was registered for C. meneghiniana.

Bottom Line: The temperature did not influence exploitation competition between MIJAC and other competitors and it was the best competitor in both temperatures.The growth of MIJAC was favored in strains exudates at 30°C, while CCAP was favored at 18°C, revealing that the optimum growth temperature was important to establish the competitive superiority.Therefore, we can propose two hypotheses: (i) different temperatures may results in production of distinct compounds that influence the competition among phytoplankton species and (ii) the target species may have different vulnerability to these compounds depending on the temperature.

View Article: PubMed Central - PubMed

Affiliation: Laboratório de Ecofisiologia e Toxicologia de Cianobactérias, IBCCF, Universidade Federal do Rio de Janeiro, CCS, Bloco G, 21949-900 Rio de Janeiro, RJ, Brazil ; Laboratório de Botânica, Instituto de Recursos Naturais, Universidade Federal de Itajubá, Avenida BPS 1303, Pinheirinho, 37500-903 Itajubá, MG, Brazil.

ABSTRACT
We studied the effect of temperature (18 and 30°C) on growth and on the exploitation and interference competition of three species: Microcystis aeruginosa (MIJAC), Planktothrix agardhii (PAT), and Cyclotella meneghiniana (CCAP). Coculturing the organisms in batch systems allowed for the examination of both competitive interactions, while the interference competition was studied in cross-cultures. The experiments were done during 10-12 days, and samples were taken for chlorophyll-a analysis, using PHYTO-PAM. The temperature did not influence exploitation competition between MIJAC and other competitors and it was the best competitor in both temperatures. PAT presented higher growth rates than CCAP in competition at 18 and 30°C. The temperature influenced the interference competition. The growth of MIJAC was favored in strains exudates at 30°C, while CCAP was favored at 18°C, revealing that the optimum growth temperature was important to establish the competitive superiority. Therefore, we can propose two hypotheses: (i) different temperatures may results in production of distinct compounds that influence the competition among phytoplankton species and (ii) the target species may have different vulnerability to these compounds depending on the temperature. At last, we suggest that both the sensitivity and the physiological status of competing species can determine their lasting coexistence.

No MeSH data available.