Microalgal Consortia for Waste Treatment and Valuable Bioproducts

Abstract

Microalgae have been considered a promising and sustainable candidate for wastewater treatment and valuable bioproducts, such as feedstocks for food, nutrients, and energy. However, many challenging bottlenecks, such as low biomass productivity, expensive biomass harvesting techniques, and inefficient extraction of biofuels restrict its large-scale commercial production. Symbiotic relationships between microalgae and bacteria, also known as microalgal consortia, have proven to be effective solutions for mitigating technical and economic limitations. The natural and artificial symbiotic microalgal consortia combine microorganisms with various metabolic activities, which leads to valuable biomass production and the removal of nutrients, pharmaceuticals, and personal care products (PPCP) from wastewater. Many microalgal consortia have been applied for various wastewater treatments with reduced energy costs and higher efficiency in recovering valuable resources. In this study we review the present research status and prospects of microalgal consortia, emphasizing the associated mechanism of microalgae consortia cooperative symbiosis and its studies on diverse environmental and biotechnological applications.

Microalgae-bacteria nexus for environmental remediation and renewable energy resources: Advances, mechanisms and biotechnological applications

“…Microalgae, providing formidable service as sources of biomass in biotechnological applications, have been exposed to various cultivation conditions to promote their growth and yield. Among these, altering the growth conditions through co-culturing with bacteria has been found to enhance the production of beneficial compounds in algae [ 49 ]. For instance, co-culturing Haematococcus lacustris with bacteria resulted in more than double biomass and a 60 % increase in the production of the antioxidant astaxanthin [ 50 ].…”

Diatom–Bacteria Interactions in the Marine Environment: Complexity, Heterogeneity, and Potential for Biotechnological Applications

“…This view has now changed, and interactions between microalgae and their microbiome are being investigated for possible useful applications [155]. Nevertheless, most of the studies produced until now concern the use of consortia made of microalgal species in the Chlorella, Scenedesmus, Tetraselmis, and Chlamydomonas genera and their associated bacteria for the removal of nutrients from eutrophic waters, wastewater treatment, biofuel, and valuable compound production [154,156,157]. According to the available literature, fewer studies have focused on the specific use of marine diatom-bacteria consortia.…”

“…The stimulatory effect of bacteria on diatom growth finds application mainly in wastewater treatment, bioremediation [156,162], and biofuel production [154]. In this regard, there is an increasing number of studies driving the development of artificial consortia specific to each application based on the interaction mechanisms occurring in the consortia [157]. For example, excess organic nutrients contaminating waters can be assimilated by diatoms and bacteria, stimulating their growth and allowing the coupling of wastewater treatment with the cultivation of the microalgae for biomass production and its exploitation for the extraction of compounds of interest [162] or bioenergy [157].…”