Raceway pond cultivation of a marine microalga of Indian origin for biomass and lipid production: A case study

doi:10.1016/j.algal.2014.07.005

Algal Research

Volume 6, Part B, October 2014, Pages 201-209

https://doi.org/10.1016/j.algal.2014.07.005 Get rights and content

Abstract

Microalgal biodiesel has emerged as the third generation biofuel with lots of business promise and environmental benefits. Marine microalgae as a source of lipid feedstock for biodiesel are preferred due to negligible requirements of incubation time, landmass and fresh water as compared with other energy crops and also due to their resistance to contamination in relatively inexpensive open pond cultivation system. In this study, the growth kinetics and lipid accumulation of a marine microalga, Chlorella variabilis (PTA-ATCC no. 12198) of Indian marine origin were studied in a 400 L raceway pond with 150 L working volume. The culture showed an average growth rate (μ) of 0.36 day^− 1 with consequent total lipid content of 10% on dry cell weight basis. An average biomass productivity of 5.78 gm^− 2 day^− 1 was obtained in the raceway pond cultivation. Maximum biomass productivity of 8.1 gm^− 2 day^− 1 was achieved during summer. The effect of seasonal variations on biomass productivity of the selected marine microalga was studied throughout the year at IIT Kharagpur campus, West Bengal, India. The lipid was extracted by using hexane as solvent and the fatty acid composition was determined by using GC and MALDI-ToF analyses to check for its suitability for biodiesel production.

Introduction

The global concern over energy and environmental security has thrown many technological challenges before the world scientific community for deriving sustainable solutions through the discovery and development of feedstock for alternative green energy. According to annual world primary energy consumption report in 2008, fossil fuels accounted for about 88% of the total primary energy consumption in which oil and coal as the major participating fuels contributed to around 65% [1]. Consumption of fossil fuel resources generates greenhouse gases (GHGs) which eventually lead to global warming and climatic changes. With the advent of modern industrialization and ever increasing demand of energy, the paradigm has shifted toward the production of carbon neutral energy sources [2]. Thus, the technology development initiatives are being directed toward mitigating environmental pollution through the sustainable production of biofuels [3]. For a country like India where the public transport has a strong presence, biodiesel attracts considerable attention as an alternative to petroleum diesel.

Microalgae have significant advantage for biodiesel production over other terrestrial oil crops; due to their rapid biomass production rate, high photosynthetic efficiency and the ability to convert light energy into storage lipid reserves [4]. On an average, microalgae produce 10–20 times higher biodiesel than energy crops and oleaginous yeasts [5]. Aquatic species program (1976–1998) indicates that microalgae can produce 5000 to 15,000 gal of biodiesel per year per acre in an open pond culture system. Sustainable and feasible production of biodiesel from microalgal origin necessitates the large scale cultivation of biomass to meet the ever increasing energy demand [6]. Several arrays of limitations and influencing environmental factors on biomass productivity of microalgal cultures have been studied meticulously [7]. Major environmental factors such as temperature, light and humidity affect outdoor cultivation of a particular microalgal species for biofuel application. In this context, the Indian scenario satisfies the criteria for outdoor cultivation of microalgal biomass. It is essential that the organisms be of Indian origin as they are best adapted to the environmental factors. Hence, the dire need to evaluate their annual productivity in concurrence with the environmental factors on outdoor cultures is shown in the present work. In this study we also focused on the lipid composition of the marine microalga indicating its suitability for biodiesel application.

Section snippets

Isolation and identification of the microalgal strain

The microalgal strain used in this study was isolated from the Jalandhar beach of Diu (a Union territory) India (located between 20° 57.584‵ latitude and 70° 16.759‵ longitude). Sea water sample was taken in 50 mL sterile bottles and brought to lab in cold condition in cool pack. Isolation of unicellular microalgae was done by serial dilution (10^− 1 to 10^− 5) and then spreading it on ASN-III agar plate. The plates were incubated for two weeks under low light (100 lx) for growth at 25 ± 2 °C in the

Preliminary studies in raceway pond

In the recent years, cultivation of microalgae has been meticulously studied in open raceway ponds than closed photobioreactors for biodiesel application due to its ease of operation and construction [13]. Demirbas and Demirbas [14] emphasized that closed systems are capital intensive and its usage is justified only when high value products are produced. In order to attain a cost-effective microalgal biomass-based biodiesel production, it is recommended to cultivate microalgae in open raceway

Conclusion

A marine microalga of Indian origin was studied in a raceway pond with a view to achieve high biomass productivity and lipid content for biodiesel production. To the best of our knowledge, this is the first report on the cultivation of a marine microalga of Indian origin for biomass and lipid production in a raceway pond. Microalgae can be grown in raceway ponds from March to October in Indian climatic conditions. Maximum possible biomass productivity of the halotolerant and thermotolerant

Acknowledgments

GDB and RS thankfully acknowledge The Council of Scientific and Industrial research (CSIR) for the financial assistance under NIMITLI program (Grant no.: 5/258/64/2009 — NMITLI; Date: 19-04-2010) on “Biofuel from marine microalgae”. GDB is grateful to Ms. Priyatama Panda for her valuable technical inputs. GS is thankful to CSIR for his individual Senior Research Fellowship. The authors also acknowledge Indian Institute of Technology Kharagpur and CSIR-CSMCRI for the infrastructural facilities

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Raceway pond cultivation of a marine microalga of Indian origin for biomass and lipid production: A case study

Abstract

Introduction

Section snippets

Isolation and identification of the microalgal strain

Preliminary studies in raceway pond

Conclusion

Acknowledgments

Renew. Sust. Energ. Rev.

Appl. Energy

Trends Biotechnol.

J. Microbiol. Methods

Resour. Conserv. Recy.

Bioresour. Technol.

Energy Convers. Manag.

Biotechnol. Adv.

Biomass

Water Res.

J. Lipid Res.

Aquaculture

Aquaculture

Climatic Change: Solutions in Sight, a Dutch Perspective

Biodiesel production current state of the art and challenges

J. Ind. Microbiol. Biotechnol.

Microalgae as a raw material for biofuels production

J. Ind. Microbiol. Biotechnol.

Quantitative assessment of the major limitations on productivity of Spirulina platensis in open raceways

J. Appl. Phycol.