The effect of changes in light availability caused by mixing on the growth of Anabaena circinalis (Nostocales, Cyanobacteria) and Aulacoseira sp. (Centrales, Bacillariophyceae)

McCausland, Malcolm A.; Thompson, Peter A.; Blackburn, Susan I.

doi:10.2216/i0031-8884-40-6-530.1

Cited by 13 publications

(9 citation statements)

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“…Line types (solid = positive and dashed = negative) are indicative of the Pearson correlation coefficient. (Brookes, 1999;McCausland et al, 2001;McCausland et al, 2005), P-limitation and dissolved N concentrations (Supplementary Table S2). The sudden collapse in the D. circinale population strongly implicates an external biological effector, such as viral lysis or bacterial predation, neither of which was addressed at length within the scope this study.…”

Section: Abioticmentioning

confidence: 99%

Microbial communities reflect temporal changes in cyanobacterial composition in a shallow ephemeral freshwater lake

et al. 2015

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The frequency of freshwater cyanobacterial blooms is at risk of increasing as a consequence of climate change and eutrophication of waterways. It is increasingly apparent that abiotic data are insufficient to explain variability within the cyanobacterial community, with biotic factors such as heterotrophic bacterioplankton, viruses and protists emerging as critical drivers. During the Australian summer of 2012-2013, a bloom that occurred in a shallow ephemeral lake over a 6-month period was comprised of 22 distinct cyanobacteria, including Microcystis, Dolichospermum, Oscillatoria and Sphaerospermopsis. Cyanobacterial cell densities, bacterial community composition and abiotic parameters were assessed over this period. Alpha-diversity indices and multivariate analysis were successful at differentiating three distinct bloom phases and the contribution of abiotic parameters to each. Network analysis, assessing correlations between biotic and abiotic variables, reproduced these phases and assessed the relative importance of both abiotic and biotic factors. Variables possessing elevated betweeness centrality included temperature, sodium and operational taxonomic units belonging to the phyla Verrucomicrobia, Planctomyces, Bacteroidetes and Actinobacteria. Species-specific associations between cyanobacteria and bacterioplankton, including the free-living Actinobacteria acI, Bacteroidetes, Betaproteobacteria and Verrucomicrobia, were also identified. We concluded that changes in the abundance and nature of freshwater cyanobacteria are associated with changes in the diversity and composition of lake bacterioplankton. Given this, an increase in the frequency of cyanobacteria blooms has the potential to alter nutrient cycling and contribute to long-term functional perturbation of freshwater systems.

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Section: Abioticmentioning

confidence: 99%

Microbial communities reflect temporal changes in cyanobacterial composition in a shallow ephemeral freshwater lake

et al. 2015

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“…Three or four replicates were grown at each of seven irradiances. Cultures were grown in modified WC medium (McCausland et al, 2001) with an additional 5 mM HEPES to aid with pH control (Smith & Foy, 1974), and were mixed daily.…”

Section: Irradiance Experimentsmentioning

confidence: 99%

“…Two mixing treatments of 10 min (MIXED treatment) and 48 h (CALM treatment), each with three replicates, were maintained for the duration of the experiment. The mixing apparatus consisted of an electronically controlled winch system that lowered and raised perforated stainless steel plungers (70 mm diameter) through the depth of the microcosms at the prescribed mixing intervals (McCausland et al, 2001).…”

Section: Microcosm Experiment: Irradiance and Mixingmentioning

confidence: 99%

Ecophysiological influence of light and mixing onAnabaena circinalis(Nostocales, Cyanobacteria)

McCausland

Thompson

Blackburn

2005

European Journal of Phycology

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The physiology (growth rate, biochemical composition and flotation rate) of the toxic cyanobacterium Anabaena circinalis was studied in relation to irradiance and mixing regime in two small-scale (250 ml or 1 l) batch culture experiments and one medium scale (1 m high, 4.4 l), semi-continuous microcosm experiment. In batch cultures, A. circinalis had a relatively high irradiance requirement as indicated by its compensation irradiance, E c (13 + 2 mmol m 72 s 71 ). The growth efficiency (a g ) of A. circinalis, estimated as the initial slope of the growth-irradiance curve , was in the mid to high range depending on the model applied (Monod: 0.33 + 0.19 m 2 mol 71 , exponential: 0.43 + 0.15 m 2 mol 71 ). The flotation rate of the A. circinalis population was 0.69 + 0.11 m d 71 at 100 mmol m 72 s 71 and decreased at higher irradiance to be negative at irradiances over 135 mmol m 72 s 71 . In a microcosm experiment, different mixing intervals were tested (10 min (MIXED) and 48 h (CALM)) across three irradiance treatments. The irradiance treatments differed in both their degree of vertical light attenuation and mean integrated irradiance. The mixing regime had no effect on growth rate in the high irradiance (HE) and medium irradiance (ME) treatments (mean integrated irradiances 60 and 15 mmol m 72 s 71 , respectively). However, an increase in A. circinalis flotation rate in the lowest irradiance treatment (LE; mean integrated irradiance 7 mmol m 72 s 71 ) resulted in a 44% higher growth rate in the CALM microcosm through access to greater irradiance. This suggests that short stable periods (e.g. diurnal stratification) in highly light limited treatments will assist the growth of A. circinalis due to its ability to gain ready access to light in the euphotic zone.

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“…Given that $90 mmol of photons m À2 s À1 is saturating for growth (McCausland et al, 2001) all of these treatments were likely to be light-limited with the green light treatment potentially most limited. The results, however, indicated that growth rates were similar for blue, cool-white, green and red light treatments.…”

Section: Growth Rates Of Vegetative Cellsmentioning

confidence: 99%

The influence of light quality on akinete formation and germination in the toxic cyanobacterium Anabaena circinalis

2009

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The effect of changes in light availability caused by mixing on the growth of Anabaena circinalis (Nostocales, Cyanobacteria) and Aulacoseira sp. (Centrales, Bacillariophyceae)

Cited by 13 publications

References 0 publications

Microbial communities reflect temporal changes in cyanobacterial composition in a shallow ephemeral freshwater lake

Microbial communities reflect temporal changes in cyanobacterial composition in a shallow ephemeral freshwater lake

Ecophysiological influence of light and mixing onAnabaena circinalis(Nostocales, Cyanobacteria)

The influence of light quality on akinete formation and germination in the toxic cyanobacterium Anabaena circinalis

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