Nutrient interactions between phytoplankton and bacterioplankton under different carbon dioxide regimes

Abstract

Light, nutrients, temperature, pH, and salinity are important factors in controlling the growth of phytoplankton and bacterioplankton. Supply of key nutrients to these communities can result in mutualistic or competitive relationships between bacterioplankton and phytoplankton. In this study, we investigated growth and uptake of nutrients by the marine prasinophyte flagellate Tetraselmis chui (strain PLY429) in the presence and absence of a community of bacterioplankton at two pH levels. Growth of PLY429 and total nutrient uptake were calculated for each treatment. The addition of bacterioplankton resulted in lower growth rates of PLY429, but the removal of ammonium was greater in those cultures with bacterioplankton present. The division rate of PLY429 was affected by pH; however, pH changes did not result in different uptake rates of nitrate, ammonium, or phosphate by the mixed algal and bacterial assemblage. These findings suggest that bacterioplankton and phytoplankton were competing for ammonium and that a lower pH resulted in more rapid algal growth.

Screening and selection of growth-promoting bacteria for Dunaliella cultures

“…Bacterial strains can also decrease ΔX max of microalgae by competing for a limiting nutrient. Such an effect has been previously reported by Meseck et al for nitrogen, and by Rhee et al and Danger et al for phosphorus [7,50,57]. Alternatively, release of toxic compounds by bacteria could also be involved in the inhibitory effect observed at the stationary phase [49,58].…”

Tetraselmis suecica F&M‐M33 growth is influenced by its associated bacteria

“…The addition of single bacterial isolates to the axenic culture led to different results: Acinetobacter and Raugeria enhanced, whereas Pseudomonas reduced algal growth (Arora et al, 2012). Meseck et al (2007) studied the influence on T. chuii of the addition of a bacterial community obtained from a Tetraselmis striata culture. The bacteria strongly reduced algal growth compared with the axenic culture.…”

“…The bacteria strongly reduced algal growth compared with the axenic culture. The authors suggested competition for ammonium to be the cause of the reduced growth (Meseck et al, 2007). Park et al (2017) evaluated the effect of addition of each of the 26 bacterial isolates obtained from T. striata phycosphere to an axenic culture and studied the two isolates (Pelagibaca bermudensis and Stappia sp.)…”

“…Few studies (Nicolas et al, 2004;Arora et al, 2012;Biondi et al, 2017) have investigated the bacterial communities associated with cultures of the marine microalga Tetraselmis (Chlorodendrophyceae, Chlorophyta) and the influence of these communities on Tetraselmis growth (Meseck et al, 2007;Arora et al, 2012;Park et al, 2017). This microalga is one of the few actually in the market, as it is widely used in aquaculture (Abiusi et al, 2014;Tredici et al, 2009;Tulli et al, 2012;Muller-Feuga, 2013).…”

Wastewater nutrient removal in a mixed microalgae–bacteria culture: effect of light and temperature on the microalgae–bacteria competition

“…The nitrification process therefore implies two negative effects in the use of microalgae for wastewater treatment: (i) the reduction of ammonium by AOB does not involve a net nitrogen reduction as it is oxidized to nitrate, which is not as easily assimilated by microalgae as ammonium [11]; (ii) the limitation of microalgae growth when the concentration of ammonium in the culture is low. In fact, Meseck et al [12] concluded that the presence of nitrifying bacteria in a microalgae culture of Tetraselmis chui reduced the specific growth rate due to their competition for nutrients. However, Risgaard-Petersen et al [13] observed that microalgae became the predominant group under non-limiting ammonium due to their higher growth rate.…”