Latest trends and developments in microalgae as potential source for biofuels: The case of diatoms

Microalgae are microscopic plants which are found in water, snow as well as land. They are one of the major resources of biofuel. However, the phenomenon of biolipid accumulation and its downstream processing into biofuel for commercialization and industrialization has yet to be standardized at economical scale. Among microalgae, diatoms are third generation microalgae which produces abundant oil and thus serves as one of the biggest sources of fossil fuel energy. They account for more than 25% of global biomass production. Diatoms would suffice world's energy crisis if they are milked/harvested for oil without being sacrificed. Simultaneously in order to get benefitted for crude oil the biochemical modeling of oleaginous microalgae would help in increasing its lipid accumulation to be able to be used in diatom solar panels for Diafuel™ (biofuel from diatoms) production. Such types of living algal solar panels grow in the presence of nitrogen, phosphorus, potassium, silicates, trace metals, few other micro nutrients and even in wastewater. Additionally, molecular tools like Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) offers targeted genome modification in diatoms for increasing oil production deploying specific genes. The review adds the scope to unravel such techniques in diatoms to harvest lipid for Diafuel™ production from a wide range of diatom strains. Several such genetically modified or naturally selected diatom strains rich in oil serve as an important ingredient for diatom solar panels. The main target of this review is to widen the scope of metabolic pathways for enhancing lipid and biofuel in diatoms under nutrient stress media and adapting genetic engineering tools to identify genes responsible for them. It also targets to study the quality of biofuel and life cycle assessment of lipids from diatoms. © 2021 Elsevier Ltd.