The influence of carbon limitation on growth of Heterosigma akashiwo: A case study in fatty acids composition

Yadi Lou; Yu Liu; Na Li; Yuxin Liu; Guoguang Wang; Xinda Zhao; Haixia Wang

doi:10.1016/j.scitotenv.2019.135700

The influence of carbon limitation on growth of Heterosigma akashiwo: A case study in fatty acids composition

Sci Total Environ. 2020 Mar 1:706:135700. doi: 10.1016/j.scitotenv.2019.135700. Epub 2019 Nov 25.

Authors

Yadi Lou¹, Yu Liu², Na Li¹, Yuxin Liu¹, Guoguang Wang¹, Xinda Zhao¹, Haixia Wang³

Affiliations

¹ College of Environmental Science and Engineering, Dalian Maritime University, Dalian, China.
² College of Environmental Science and Engineering, Dalian Maritime University, Dalian, China; Environmental Information Institute, Dalian Maritime University, Dalian, China. Electronic address: ylsibo@foxmail.com.
³ Navigation College, Dalian Maritime University, Dalian, China.

PMID: 31818562
DOI: 10.1016/j.scitotenv.2019.135700

Abstract

Heterosigma akashiwo is an algal blooms species, and thus selected as the target microalgae in this work. This study attempted to investigate the influence of carbon limitation on the growth of H. akashiwo. Experiments were carried out in CO₂-unlimited and CO₂-limited systems (both include three nutritional groups). The stable isotope signatures and compound-specific stable three nutritional groups carbon isotopic composition of fatty acids were measured. Here we hypothesized that the carbon limitation could lead to the enriched of stable isotope ratios in the H. akashiwo. The results showed that carbon limitation made δ¹³C and δ¹³C_FAs values more and more enriched in H. akashiwo. δ¹³C values were enriched in normal group of H. akashiwo within CO₂-limited. δ¹⁵N values were enriched in nitrogen deficiency of H. akashiwo within both CO₂-unlimited and CO₂-limited. Furthermore, compared with the exponential phase, the enriched in δ¹³C was detected during the stationary phase in H. akashiwo within CO₂-limited. A total of 8 major FAs were detected in H. akashiwo. Within CO₂-unlimited, nitrogen deficiency promoted the synthesis of 4 FAs (14:1n-5c, 16:0, 18:0 and 18:3n-6c) in exponential phase. Within CO₂-limited, nitrogen deficiency promoted the synthesis of FAs 14:0, 16:0 and 18:3n-3c, while phosphorus deficiency promoted the synthesis of all 6 FAs in exponential phase. δ¹³C_FAs of H. akashiwo within CO₂-limited showed the valley values and were significantly greater than those within CO₂-unlimited. Furthermore, δ¹³C_FAs of stationary phase were greater than those of exponential phase. δ¹³C_14:1n-5c in nitrogen deficiency were the highest of the three nutrient groups within CO₂-unlimited. This may point out that δ¹³C_FAs could become an indicator of marine phytoplankton blooms. Overall, the present study may provide a novel approach to investigate the physiology and lipid metabolism of H. akashiwo blooms by using stable isotope ratios coupled with FAs profiles.

Keywords: CO(2)-limited; CO(2)-unlimited; CSIA; Fatty acids; GC-IRMS; Heterosigma akashiwo.

MeSH terms

Carbon
Fatty Acids
Microalgae*
Phytoplankton
Stramenopiles*

Substances

Fatty Acids
Carbon