Prevalent pH Controls the Capacity of Galdieria maxima to Use Ammonia and Nitrate as a Nitrogen Source

Manuela Iovinella; Dora Allegra Carbone; Diana Cioppa; Seth J Davis; Michele Innangi; Sabrina Esposito; Claudia Ciniglia

doi:10.3390/plants9020232

Prevalent pH Controls the Capacity of Galdieria maxima to Use Ammonia and Nitrate as a Nitrogen Source

Plants (Basel). 2020 Feb 11;9(2):232. doi: 10.3390/plants9020232.

Authors

Manuela Iovinella¹, Dora Allegra Carbone², Diana Cioppa², Seth J Davis^{1

3}, Michele Innangi⁴, Sabrina Esposito⁴, Claudia Ciniglia⁴

Affiliations

¹ Department of Biology, University of York, York YO105DD, UK.
² Department of Biology, University of Naples Federico II, 80126 Naples, Italy.
³ Key Laboratory of Plant Stress Biology, School of Life Sciences, Henan University, Kaifeng 475004, China.
⁴ Department of Environmental, Biological and Pharmaceutical Science and Technology, University of Campania "L. Vanvitelli", 81100 Caserta, Italy.

Abstract

Galdieria maxima is a polyextremophilic alga capable of diverse metabolic processes. Ammonia is widely used in culture media typical of laboratory growth. Recent reports that this species can grow on wastes promote the concept that G. maxima might have biotechnological utility. Accordingly, there is a need to know the range of pH levels that can support G. maxima growth in a given nitrogen source. Here, we examined the combined effect of pH and nitrate/ammonium source on the growth and long-term response of the photochemical process to a pH gradient in different G. maxima strains. All were able to use differing nitrogen sources, despite both the growth rate and photochemical activity were significantly affected by the combination with the pH. All strains acidified the NH₄⁺-medium (pH < 3) except G. maxima IPPAS P507. Under nitrate at pH ≥ 6.5, no strain was able to acidify the medium; noteworthy, G. maxima ACUF551 showed a good growth performance under nitrate at pH 5, despite the alkalization of the medium.

Keywords: Galdieria; ammonium; nitrate; pH.