Screening and Evaluation of Some Green Algal Strains (Chlorophyceae) Isolated from Freshwater and Soda Lakes for Biofuel Production

Ramganesh Selvarajan,Tamás Tauber,Elumalai Sanniyasi,Timothy Sibanda,Memory Tekere,Tamás Felföldi

doi:10.3390/en8077502

Abstract

Microalgae are photosynthetic microorganisms that can produce lipids, proteins and carbohydrates in large amounts and within short periods of time and these can be processed into both biofuels and other useful commercial products. Due to this reason microalgae are considered as a potential source of renewable energy; and one of the most important decisions in obtaining oil from microalgae is the choice of species. In this study, the potential of Chlorophyceae species isolated from freshwater and soda lakes in Hungary and Romania (Central Europe) were characterized and evaluated by determining their biomass accumulation, lipid productivity, fatty acid profiles, and biodiesel properties besides protein and carbohydrate productivity. Out of nine strains tested, three accumulated more than 40% dry weight of protein, four accumulated more than 30% dry weight of carbohydrate and the strain Chlorella vulgaris LC8 accumulated high lipid content (42.1% ± 2.6%) with a favorable C16-C18 fatty acid profile (77.4%) as well as suitable biodiesel properties of high cetane number (57.3), low viscosity (4.7 mm2/s), lower iodine number (75.18 g I2/100 g), relative cloud point (8.8 °C) and negative cold filter plugging point (−6.5 °C). Hence the new strain, Chlorella vulgaris LC8 has potential as a feedstock for the production of excellent quality biodiesel.

Highlights

Global consumption of crude oil is predicted to grow continuously
Temperature, pH and conductivity of each sample were determined in situ with a Multi-Line P4 meter (Wissenschaftlich-Technische Werkstätten, Weilheim, Germany) and the samples were transported to the laboratory in a thermo box in dark conditions
Screening and evaluation of potential green algal strains viz biomass productivity, lipid cell content, fatty acids and fuel properties are some of the key parameters that determine the economic feasibility of algal oils for biodiesel production

Summary

Introduction

Global consumption of crude oil is predicted to grow continuously. This explains why despite improvements in the recovery of traditional fossil fuels, more attention needs to be paid to the search for clean and viable alternative renewable energy resources with the prospect of minimizing increases in atmospheric CO2 by recycling carbon from the atmosphere [1,2,3].Algae are a large and highly diverse group of organisms which can be found in almost all ecosystems [4].Microalgae are a promising feedstock for biofuel production [5,6] and different applications, such as wastewater purification [7,8,9,10], biogas production [11,12], and extraction of value added compounds for food and pharmaceutical products [13]. Global consumption of crude oil is predicted to grow continuously. This explains why despite improvements in the recovery of traditional fossil fuels, more attention needs to be paid to the search for clean and viable alternative renewable energy resources with the prospect of minimizing increases in atmospheric CO2 by recycling carbon from the atmosphere [1,2,3]. Algae are a large and highly diverse group of organisms which can be found in almost all ecosystems [4]. An important aspect of biodiesel production is the selection of a suitable algal species [14]. Selected strains should have two important key characteristics: high biomass productivity as well as adaptation to regional climatic conditions [15,16]

Methods

Results

Conclusion