Microalgae-bacteria symbiosis in microalgal growth and biofuel production: a review

Abstract

Photosynthetic microalgae can capture solar energy and convert it to bioenergy and biochemical products. In nature or industrial processes, microalgae live together with bacterial communities and may maintain symbiotic relationships. In general interactions, microalgae exude dissolved organic carbon that becomes available to bacteria. In return, the bacteria remineralize sulphur, nitrogen and phosphorous to support the further growth of microalgae. In specific interactions, heterotrophic bacteria supply B vitamins as organic cofactors or produce siderophores to bind iron, which could be utilized by microalgae, while the algae supply fixed carbon to the bacteria in return. In this review, we focus on mutualistic relationship between microalgae and bacteria, summarizing recent studies on the mechanisms involved in microalgae-bacteria symbiosis. Symbiotic bacteria on promoting microalgal growth are described and the relevance of microalgae-bacteria interactions for biofuel production processes is discussed. Symbiotic microalgae-bacteria consortia could be utilized to improve microalgal biomass production and to enrich the biomass with valuable chemical and energy compounds. The suitable control of such biological interactions between microalgae and bacteria will help to improve the microalgae-based biomass and biofuel production in the future.

Diatoms recovery from wastewater: Overview from an ecological and economic perspective

“…In the future, diatoms will remain as the best candidate for biofuel production. Some strain of diatoms produces lipids as 50% to 80% of the dry weight that can be used in the production of biofuel thereby focusing on the role of diatoms as an ideal substitute for fossil fuels [ 16 ]. Despite having all these important characteristics, they are the least explored aquatic species because isolation and maintenance of axenic culture is a tedious job [ 17 ].…”

Environmental Factors and Pollution Stresses Select Bacterial Populations in Association With Protists

“…It was possible that the endosymbiotic green algae Chlorella sp. became more carbon-rich at higher temperatures (Serra-Maia et al, 2016), which could supply more organic matter to the symbiotic Pseudomonas species (Yao et al, 2019). An opposite trend was observed for the dominant DRB group in the algae-free ciliate E. vannus, in which the relative abundance of Pseudoalteromonas species decreased progressively with the increase of temperature ( Figure 4A).…”

A qPCR method for distinguishing biomass from non-axenic terrestrial cyanobacteria cultures in hetero- or mixotrophic cultivations

“…Many studies have shown that cyanobacteria live in symbiosis with heterotrophic bacteria. These supply the cyanobacteria with important secondary metabolites and in return receive carbohydrates or nitrogen compounds (Thompson et al 2012;Kouzuma and Watanabe 2015;Yao et al 2019).…”