Potential to resist biological contamination in marine microalgae culture: Effect of extracellular substances of Nannochloropsis oceanica on population growth of Euplotes vannus and other protozoa

Lu Zhao; Yan Zhang; Xianhui Geng; Xiaowen Hu; Xinming Zhang; Henglong Xu; Guanpin Yang; Kehou Pan; Yong Jiang

doi:10.1016/j.marpolbul.2021.112868

Potential to resist biological contamination in marine microalgae culture: Effect of extracellular substances of Nannochloropsis oceanica on population growth of Euplotes vannus and other protozoa

Mar Pollut Bull. 2021 Nov:172:112868. doi: 10.1016/j.marpolbul.2021.112868. Epub 2021 Aug 18.

Authors

Lu Zhao¹, Yan Zhang², Xianhui Geng², Xiaowen Hu³, Xinming Zhang³, Henglong Xu², Guanpin Yang², Kehou Pan², Yong Jiang⁴

Affiliations

¹ College of Marine Life Sciences & Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, China; College of Marine Engineering, RIZHAO Polytechnic, Rizhao, China.
² College of Marine Life Sciences & Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, China.
³ College of Marine Engineering, RIZHAO Polytechnic, Rizhao, China.
⁴ College of Marine Life Sciences & Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, China; Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, China. Electronic address: yongjiang@ouc.edu.cn.

PMID: 34418712
DOI: 10.1016/j.marpolbul.2021.112868

Abstract

The commercially important marine microalgae Nannochloropsis oceanica is easily ingested by protozoan predators during large-scale cultivation. However, investigations into the effect of microalgae on the growth of protozoa are scant. A feeding experiment was conducted with Euplotes vannus grazing on different concentrations of N. oceanica. The ciliate population was significantly lower in the high concentration of algae than that in the low or medium algal concentration treatments. The density of ciliates cultured in algae filtrate media was significantly lower than that in lysate media and the blank control. Furthermore, the algal cell filtrate was added to three other protozoan populations, and they all gradually lost their ability to move and their body shape changed. This study investigated the interactions between N. oceanica and protozoan predators and provides insight on using microalgal extracellular substances to control biological contamination in the future.

Keywords: Extracellular secretion; Marine protozoa; Microalgae; Nannochloropsis oceanica; Population growth.

MeSH terms

Euplotes*
Microalgae*
Population Growth
Stramenopiles*