Physiological Changes of Parachlorella Kessleri TY02 in Lipid Accumulation under Nitrogen Stress.

Yifan Gao,Junping Lv,Shulian Xie,Xudong Liu,Fangru Nan,Jia Feng,Qi Liu

doi:10.3390/ijerph16071188

Abstract

In order to study the effects of nitrogen stress on the lipid synthesis of Parachlorella kessleri TY02 and to understand the changes in growth, photosynthetic pigments, total protein and total carbohydrate contents during lipid accumulation, the cells of the strain were cultured in nitrogen-deficient (N−) and nitrogen-rich (N+) media for one week. Changes in cell growth, chlorophyll content, chlorophyll fluorescence parameters, neutral lipid and total lipid content, total protein content and total carbohydrate content were measured and analyzed. The results showed that, under nitrogen stress, the algal strain grew slowly, and chlorophyll and total protein contents decreased, while total carbohydrate and total lipid contents increased. This indicated that, under nitrogen stress, most of the carbon flowed to the synthesis of lipids and carbohydrates. Meanwhile, reducing the nitrogen content was a relatively economical and easy to operate method of promoting lipid accumulation.

Highlights

With the rapid trend of modernization, more and more energy is needed
The results show that nitrogen stress was beneficial to the accumulation of neutral in P. kessleri neutral lipids in P. kessleri TY02
Nitrogen is oneisofone theofmost important nutrient factors that restricts the growth of microalgae and and it is essential for microalgae to maintain normal metabolism

Summary

Introduction

With the rapid trend of modernization, more and more energy is needed. The accelerated consumption of petroleum, coal and other fossil energy gives rise to two major problems—energy shortage and environmental pollution. Biodiesel is considered a good alternative to fossil energy due to its high combustion performance, wide application range, safety and reliability, as well as its being less detrimental to the environment. Microalgae have many merits of their own, such as diverse species, wide distribution, fast growth, rich in oil and fat, and no occupation of cultivated land, which makes them ideal biodiesel raw materials [3,4,5]. The research on microalgae biodiesel in China is still in the initial stage and the high harvesting cost and low oil yield are still two key factors hindering its development. The primary tasks of industrialized production include screening and cultivating high-lipid algal strains, as well as optimizing cultivation conditions [6]

Methods

Discussion

Conclusion