Comparative growth characteristics and interspecific competitive interaction of two cyanobacteria, Phormidium autumnale and Nostoc sp.

Abstract

This study examined the growth characteristics and competitive interaction of two cyanobacteria, Phormidium autumnale GJ_2B_I1 and Nostoc sp. DS_2B_I1, which were newly isolated from a southeast river (Nakdong) during the cyanobacterial harmful algal bloom (CyanoHAB) season in Korea. As major environmental parameters, water temperature (25 and 30 °C) and alkalinity (19–78 mg CaCO3 L–1) and nitrate concentration (1.5–3.5 mg NO3–N L–1) were selected based on the water environmental monitoring data during the CyanoHAB season. Unlike P. autumnale, Nostoc sp. has a relatively high growth rate under both monoculture and co‐culture and prefers the maximum environmental conditions (30 °C and 78 mg CaCO3 L–1; pH 9) during the CyanoHAB season. In addition, the growth of P. autumnale is relatively unaffected by alkalinity. Nitrogen (N) stress also has a limiting effect in the interspecific interactions of both cyanobacterial strains. All other cases except for Nostoc sp. in a co‐culture showed a considerable increase in growth rate with increasing N content (1.5–3.5 mg NO3–N L–1), showing 20–64% under the minimum field conditions (25 °C and 19 mg CaCO3 L–1; pH 7) and 18–140% under the maximum field conditions. The results show that the growth of P. autumnale can be stimulated by enhanced N stress. On the other hand, Nostoc sp. is less affected by N stress compared with P. autumnale. Therefore, it has excellent potential to be a major group of CyanoHABs because of their relatively high growth rate, particularly in the range of N tested.

Assessment of nitrogen interaction with temperature on the growth and toxin production of mat-forming toxin-producing Anagnostidinema carotinosum

“…Nitrogen has been reported as an essential limiting nutrient for algae growth and cellular metabolism. The substantial increase in the growth was comparable to previous studies on other algal species subjected to N enrichment (Baldia et al, 2007; dos Santos Silva et al, 2022; Yadav et al, 2021a). In addition, the growth was significantly stimulated by temperatures of 30 and 34°C, when nitrate concentrations increased from 2.5 to 4.5 mg l −1 .…”

“…The geographical location of sampling site of Nakdong River, South Korea (Source from Anchul et al, 2016; Yadav et al, 2021a). …”

“…Several environmental factors were associated with the invasive species, composition and intensification of blooms, including increasing temperature and nutrient loads in the Nakdong River water (Kim et al, 2020; Park et al, 2021). Yadav et al (2021a) recently investigated abiotic factors like pH, temperature and nutrients on the growth patterns of bloom‐forming cyanobacterial species Amazoninema brasiliense , Microcystis elabens and Nododsilinea nodulosa isolated for the first time from Nakdong River water. In lotic systems, there is not much information on the synergetic effects of the environmental variables cyanobacterial growth and toxin production (Heath et al, 2016).…”