The right stuff; realizing the potential for enhanced biomass production in microalgae

Abstract

There is growing evidence that eukaryotic microalgae can become a more sustainable and profitable alternative than terrestrial crops to produce feed, fuels, and valuable coproducts. The major factor driving progress in algal biomass production is the potential of microalgae to produce substantially greater biomass per unit land area than terrestrial crops. To be financially feasible, however, current algal biomass yields must be increased. Given the fact that algal biomass production is in its infancy there exist multiple opportunities to improve biomass yields. For example, recent bioprospecting efforts have led to the identification of new microalgal strains having biomass yields that compete economically with plant biomass. Substantial increases in biomass yields have also been achieved using advanced genetic engineering approaches. Targeted improvements in photosynthetic efficiency have led to three-fold increases in algal biomass yields. One genetic tool that has seen limited application for algal biomass enhancement is advanced breeding genetics. The greater availability of algal genomes and recent advancements in breeding algae will further accelerate yield improvements. Genetic engineering strategies to increase biomass production will also be assisted by transcriptomic and metabolomic studies that help identify metabolic constraints that limit biomass production. In this review we assess some of the recent advances in algal strain selection, directed evolution, genetic engineering and molecular-assisted breeding that offer the potential for increased algal biomass production.

Machine learning for algal biofuels: a critical review and perspective for the future

“…56 The progress may speed up in future with the new genetic modifications as Subramanian and Sayre argued that it is possible to have a three fold improvement in the algal biomass yield by genetic modification of wild strains. 59 However, for a bright future, significant challenges that exist in almost all steps like strain isolation, nutrient sources, harvesting, fuel extraction and conversion have to be resolved. 60 Producing low-cost algal biofuel is difficult with the current state of the art because a great deal of energy and resources, including water, are needed for cultivating algae, recirculating the nutrients and drying the biomass.…”

“…56 The progress may speed up in future with the new genetic modifications as Subramanian and Sayre argued that it is possible to have a three fold improvement in the algal biomass yield by genetic modification of wild strains. 59…”

Quantity and Quality of Light on Growth and Pigment Content of Dunaliella sp. and Anabaena sp. Cultures and the Use of Their Absorption Spectra as a Proxy Method for Assessment

“…Microalgae are a widespread and rapidly growing branch of primary production, as they offer many and important advantages in terms of biomass production [1][2][3][4]. From an ecological point of view, they can contribute significantly to curbing anthropogenic carbon emissions, becoming a useful tool in the arsenal of climate change mitigation [5,6].…”

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“…Despite the great interest in BECCS, growing fuel crops such as switchgrass to harness photosynthetic productivity at industrial scale still poses a major disadvantage in the areal requirement for arable land. Cyanobacteria and microalgae boast a significantly greater areal productivity and CO 2 fixation rate and can yield ~4 fold higher biomass (Subramanian and Sayre, 2022), and 15-300-fold more oil production than terrestrial plants (Chisti, 2007;Hempel et al, 2012;Rehman et al, 2022). Furthermore, cultivation of microalgae and cyanobacteria can be conducted in open ponds or closed vessels on non-arable land, thereby avoiding direct competition for limited agricultural land for the production of biomass (Righelato and Spracklen, 2007).…”