Effect of Environmental Factors on Nitrite Nitrogen Absorption in Microalgae–Bacteria Consortia of Oocystis borgei and Rhodopseudomonas palustris

Abstract

The effects of temperature, salinity, and illumination on the nitrite uptake rate of the microalgae–bacteria consortia of Oocystis borgei and Rhodopseudomonas palustris were investigated. The absorption rates of nitrite and the contribution rate of each component in the consortia under different temperatures (15, 20, 25, 30, 35 °C), illuminations (0, 15, 25, 35, 45 μmol·m−2·s−1), and salinities (0, 5, 15, 25, 35‰) were determined by stable isotope labeling technique. The single and combined effects of three environmental factors on nitrite uptake by the microalgae–bacteria consortia were analyzed using single-factor and orthogonal experiments. The single-factor experiment showed that the microalgae–bacteria consortia could absorb nitrite efficiently when the temperature, salinity, and illumination were 20~30 °C, 0~15‰, and 25~45 μmol·m−2·s−1, respectively, with the highest absorption rates were 2.086, 3.058, and 2.319 μg∙g−1∙h−1, respectively. The orthogonal experiment showed that the most efficient environmental conditions for nitrite uptake were 30 °C, 5‰ salinity, 35 μmol·m−2·s−1 illumination, and the rate of nitrite uptake by the microalgae–bacteria consortia was 3.204 μg∙g−1∙h−1. The results showed that the nitrite uptake rate of the O. borgei–R. palustris consortia was most affected by temperature, followed by salinity, and least by illumination. Under the same conditions, the nitrite absorption capacity of the microalgae–bacteria consortia was greater than that of single bacteria or algae, and R. palustris played a major role in the nitrite absorption of the consortia. The O. borgei and R. palustris consortia still maintain high nitrite absorption efficiency when the environment changes greatly, which has broad application prospects in the regulation and improvement of water quality in shrimp culture.

Exploring the potential of Candida sp. as probiotic for enhancing water quality in aquaculture

“…In another study, water temperature of ≤17 °C resulted in a low removal e ciency for total nitrogen and nitrate-N, while ammonium nitrogen removal decreased when water temperature was ≤11 °C (Wang et al, 2023). In addition to temperature, salinity is another crucial factor in uencing nitrogen removal, as it affects the nitrogen metabolism absorption capacity of the microalgae-bacteria consortia (Ma et al, 2023). Therefore, it is believed that under optimal conditions, probiotics would present the highest performance in removing nitrogen metabolites from water.…”

Effects of Nitrogen on the Bacterial Microbiome Community of Oocystis borgei, an Alga Widely Used in Marine Aquaculture

“…Pei et al [47] compared the environmental factors, such as nitrogen, temperature, pH, salinity, and dissolved oxygen, and found that nitrogen had a key influence on the epibiont community of Gracilariopsis lemaneiformis. Meanwhile, Ma et al [24] investigated the symbiotic system of O. borgei and bacteria and found that temperature had the greatest impact on nitrite uptake rate, followed by salinity, while light intensity had the smallest impact. This study found that at high nitrogen concentrations, both ammonium nitrogen and chlorophyll a were positively correlated with changes in the epibiont community and diversity of O. borgei.…”

“…It is necessary to maintain the balance of algae and bacteria in a water environment to regulate water quality by using O. borgei in shrimp culture. This organism can team up with Rhodopseudomonas palustris to establish a synergistic algae-bacteria consortia that is adept at taking up various nitrogen compounds, thereby enhancing water purification [24]. It has been indicated that the dominance of O. borgei in microalgae communities can contribute to enhancing water quality and managing the proliferation of bacteria associated with L. vannamei diseases [25].…”