Outdoor Growth Characterization of an Unknown Microalga Screened from Contaminated Chlorella Culture.

Shuhao Huo,Zhenhong Yuan,Changhua Shang,Fengjie Cui,Renjie Dong,Feifei Zhu,Weizheng Zhou,Zhongming Wang

doi:10.1155/2017/5681617

Abstract

Outdoor microalgae cultivation process is threatened by many issues, such as pest pollution and complex, changeable weather. Therefore, it is difficult to have identical growth rate for the microalgae cells and to keep their continuous growth. Outdoor cultivation requires the algae strains not only to have a strong ability to accumulate oil, but also to adapt to the complicated external environment. Using 18S rRNA technology, one wild strain Scenedesmus sp. FS was isolated and identified from the culture of Chlorella zofingiensis. Upon contamination by Scenedesmus sp., the species could quickly replace Chlorella zofingiensis G1 and occupy ecological niche in the outdoor column photobioreactors. The results indicated that Scenedesmus sp. FS showed high alkali resistance. It also showed that even under the condition of a low inoculum rate (OD680, 0.08), Scenedesmus sp. FS could still grow in the outdoor raceway pond under a high alkaline environment. Even under unoptimized conditions, the oil content of Scenedesmus sp. FS could reach more than 22% and C16–C18 content could reach up to 79.68%, showing that this species has the potential for the biodiesel production in the near future.

Highlights

Due to the exorbitant cost input into nutritive salts such as chemical fertilizers and high energy consumption in microalgae harvest, the microalgal biodiesel has not yet been successfully applied in commercial production [1,2,3,4]
Colonies of microalgae were isolated from contaminated Chlorella zofingiensis G1 in an outdoor photobioreactor in the district of Sanshui, Foshan city, China (23∘03󸀠N–112∘09󸀠E)
Using 18 s rDNA molecular technology, the dominant microalgae strain screened from contaminated Chlorella zofingiensis G1 in an outdoor photobioreactor was identified

Summary

Introduction

Due to the exorbitant cost input into nutritive salts such as chemical fertilizers and high energy consumption in microalgae harvest, the microalgal biodiesel has not yet been successfully applied in commercial production [1,2,3,4]. Utilizing sunlight to magnify the cultivation of microalgae under outdoor conditions is an effective way to reduce the cost of microalgal cultivation. Rotifers and protozoa are the two organisms that are able to seize ecosystem niche quickly due to their small body, simple structure, and fast reproduction speed. They prey on microalgae cells, resulting in a great reduction of microalgae cell concentration, and exceedingly threatening the microalgae production. The complex and changeable outdoor weather conditions make the cultivation of microalgae have an uneven growth rate and production is often difficult to be carried out [8,9,10]

Methods

Results

Conclusion