Sustainable Diesel Feedstock: a Comparison of Oleaginous Bacterial and Microalgal Model Systems
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The key to sustainable and commercially viable biodiesel production relies primarily on species selection. Oleaginous species with high biomass productivity, lipid content, and lipid productivity are desirable. High growth rate of the species results in high biomass productivity, which leads to high lipid productivity. It is known that algal oil technology lacks commercial feasibility predominantly due to low biomass productivity and other factors. The use of a faster-growing organism, such as oleaginous bacteria, could offset this major disadvantage. Thus, the current study analyzes two model oleaginous systems: Rhodococcus opacus PD630 (a bacterium) and Chlorella vulgaris NIOT5 (a microalga) for their growth rate and lipid productivity. It was found that the bacterial growth rate was 25-fold the microalgal growth rate. The bacterium also showed 57-fold higher biomass productivity and 75-fold higher biodiesel productivity. Further, the analysis of a large number of literature data from relevant studies under different cultivation conditions showed that R. opacus PD630 has productivities far higher than various autotrophic microalgae. Similarly, a frequency distribution of data collected from the literature showed that Rhodococcus sp. has productivities in the higher range as compared to heterotrophic microalgae. Thus, bacteria could serve as a better alternative to microalgae toward developing a commercially viable biofuel technology. Further, the biodiesel characterization study showed that the quality of diesel from the bacterium was better than that from the microalga.
KeywordsLipid productivity R. opacus Biodiesel Sustainability Growth rate Biomass productivity
The authors thank the Department of Science and Technology (DST, grant no. SB/S3/CE/007/2013) and the Department of Biotechnology (DBT, grant ref. no. BT/PR11328/PBD/26/176/2008), Government of India, for financial assistance.
Compliance with Ethical Standards
Conflict of Interest
The authors declare that they have no conflict of interest.
This article does not contain any studies with human participants or animals performed by any of the authors.
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