Central European Journal of Biology

, Volume 9, Issue 2, pp 156–162

Effects of nitrogen on growth and carbohydrate formation in Porphyridium cruentum

Authors

  • Ali Razaghi
    • Biological and Environmental SciencesUniversity of Gothenburg
  • Anna Godhe
    • Biological and Environmental SciencesUniversity of Gothenburg
    • Chemical and Biological Engineering — Industrial BiotechnologyChalmers University of Technology
Research Article

DOI: 10.2478/s11535-013-0248-z

Cite this article as:
Razaghi, A., Godhe, A. & Albers, E. cent.eur.j.biol. (2014) 9: 156. doi:10.2478/s11535-013-0248-z

Abstract

The microalga Porphyridium cruentum (Rhodophyta) has several industrial and pharmaceutical uses, especially for its polysaccharide production. This study aimed to investigate the influence of nitrogen levels as reflected by altered N:P ratios on the production and content of biomass and carbohydrate. N:P molar ratios were altered in batch cultures to range from 1.6 to 50 using the Redfield ratio of 1:16 as reference. Algal growth (estimated as final cell number, biomass concentration and maximum specific growth rate) was negatively affected at low N:P ratios. The optimal N:P ratio for growth was identified at 35–50, with specific growth rates of 0.19 day−1 and maximum cell concentrations of 59·108 cells L−1 and 1.2 g dry weight of biomass L−1. In addition, variation in cell size was seen. Cells with larger diameters were at higher N:P ratios and smaller cells at lower ratios. The cellular carbohydrate content increased under reduced nitrogen availability. However, because accumulation was moderate at the lowest N:P ratio, 0.4 g per g dry weight biomass compared to 0.24 at the Redfield ratio of 16:1, conditions for increased total carbohydrate formation were identified at the N:P ratios optimal for growth. Additionally, carbohydrates were largely accumulated in late exponential to stationary phase.

Keywords

Rhodophyta Red algae Redfield ratio Nitrogen-to-phosphorous ratio

Copyright information

© Versita Warsaw and Springer-Verlag Wien 2014