Temperature affects the silicate morphology in a diatom

Abstract

Silica deposition by diatoms, a common component of the phytoplankton, has attracted considerable interest given the importance in ecology and materials science. There has recently been a great deal of research into the biological control of biosilicifcation, yet the in vivo physical and chemical effects have not been quantitatively investigated. We have grown the marine diatom Thalassiosira pseudonana in batch culture at three temperatures (14o, 18o, and 23 °C). We observed three distinct temperature-dependent growth phases. The morphology of silica was investigated using scanning electron microscopy followed by image analysis and supervised learning. The silica in the valves of the same species showed different structures: a mesh-like pattern in silicon-rich cultures and a tree-like pattern in silicon-limited cultures. Moreover, temperature affected this silica pattern, especially in silicon-limited cultures. We conclude that cells grown at 14 °C and 18 °C divide more successfully in Si-limited conditions by developing a tree-like pattern (lower silicification).

Silicon utilization by sponges: an assessment of seasonal changes

“…It has long been determined that the seasonal variability in some environmental factors (e.g. inorganic nutrient ratios, seawater temperature, salinity, oxygen distribution) triggers drastic changes in the performance of diatoms, which may increase or decrease their rates of DSi utilization by orders of magnitude in response to those changes (Brzezinski et al 2008, Hoffmann et al 2008, Javaheri et al 2015. Through evolution, sponges are expected to have also evolved their physiology to adapt to the seasonal environmental changes.…”

Intraspecific Diversity in the Cold Stress Response of Transposable Elements in the Diatom Leptocylindrus aporus

“…Many cases of novel genetic variation have been shown after years of maintenance in culture collection [9][10][11]. Considering the high adaptability of diatoms, it could be hard to interpret the intra-specific algal diversity observed in related studies as the result of (a) adaptation to the natural environment from which strains were isolated or (b) evolutionary changes while being in culture.Temperature is a very significant environmental variable that affects the physiological response of diatoms and ultimately determines their phenological patterns and geographic ranges [12][13][14], as well as one of the parameters that is usually kept constant in culture conditions. An increase in temperature leads to an increase in enzyme activity in metabolic processes, including photosynthesis and respiration, so the cells are expected to grow faster.…”

“…A recent study on the molecular mechanisms of temperature acclimation and adaptation in warm and cold adapted strains of the marine diatom Chaetoceros concluded that evolutionary change in baseline gene expression is a key mechanism used by diatoms to adapt to different growth temperatures [17]. However, there are temperature limits, which differ for each species and even for strains of the same species isolated from warm or cold waters [8,13,14]. Temperatures close to their environmental extremes might activate stress-related pathways engaged in restoring cellular homeostasis.…”

“…Temperature is a very significant environmental variable that affects the physiological response of diatoms and ultimately determines their phenological patterns and geographic ranges [12][13][14], as well as one of the parameters that is usually kept constant in culture conditions. An increase in temperature leads to an increase in enzyme activity in metabolic processes, including photosynthesis and respiration, so the cells are expected to grow faster.…”

Optimization of a high‐throughput phenotyping method for chain‐forming phytoplankton species

“…Since diatoms undergo a size reduction as result of cell division (Round et al ), one cannot assume that standard curves generated for a strain remain constant and should therefore be re‐estimated at the beginning of an experimental setup. The length of this time period is mainly dependent on the culture conditions, which affect cell division rates (Javaheri et al ). While keeping Thalassiosira weissflogii in constant exponential phase for 3 months, Armbrust and Chisholm (), observed a decreased in cell size by 50%.…”