Synergy between microalgae and microbiome in polluted waters

Ashraf, Noreen; Ahmad, Feroz; Lu, Yandu

doi:10.1016/j.tim.2022.06.004

Cited by 43 publications

(23 citation statements)

References 92 publications

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“…Microalgae and other microbes have been known to interact both mutually and competitively in a polluted environment such as industry effluents and sewage. The interactions have been supported through nutritional reciprocity, chemotaxis, communication through volatile organic compounds and signal transduction between microalgae and microbiome present in the wastewater environment ( Ashraf et al., 2022 ; Astafyeva et al., 2022 ; Chegukrishnamurthi et al., 2022 ).…”

Section: Production Of Microalgae Based Bio Fertilizers and Biostimul...mentioning

confidence: 99%

Microalgae as next generation plant growth additives: Functions, applications, challenges and circular bioeconomy based solutions

2023

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Sustainable agriculture practices involve the application of environment-friendly plant growth promoters and additives that do not negatively impact the health of the ecosystem. Stringent regulatory frameworks restricting the use of synthetic agrochemicals and the increase in demand for organically grown crops have paved the way for the development of novel bio-based plant growth promoters. In this context, microalgae biomass and derived agrochemicals offer novel sources of plant growth promotors that enhance crop productivity and impart disease resistance. These beneficial effects could be attributed to the presence of wide range of biomolecules such as soluble amino acid (AA), micronutrients, polysaccharides, phytohormones and other signaling molecules in microalgae biomass. In addition, their phototrophic nature, high photosynthetic efficiency, and wide environmental adaptability make them an attractive source of biostimulants, biofertilizers and biopesticides. The present review aims to describe the various plant growth promoting metabolites produced by microalgae and their effects on plant growth and productivity. Further, the effects elicited by microalgae biostimulants with respect to different modes of applications such as seed treatments, foliar spray and soil/root drenching is reviewed in detail. In addition, the ability of microalgae metabolites to impart tolerance against various abiotic and biotic stressors along with the mechanism of action is discussed in this paper. Although the use of microalgae based biofertilizers and biostimulants is gaining popularity, the high nutrient and water requirements and energy intensive downstream processes makes microalgae based technology commercially unsustainable. Addressing this challenge, we propose a circular economy model of microalgae mediated bioremediation coupled with biorefinery approaches of generating high value metabolites along with biofertilizer applications. We discuss and review new trends in enhancing the sustainability of microalgae biomass production by co-cultivation of algae with hydroponics and utilization of agriculture effluents.

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Section: Production Of Microalgae Based Bio Fertilizers and Biostimul...mentioning

confidence: 99%

Microalgae as next generation plant growth additives: Functions, applications, challenges and circular bioeconomy based solutions

2023

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“…detected and metabolized by bacteria (Ashraf et al, 2022;Raina et al, 2022). Bacteria exhibit chemotaxis to a range of algal exudates, which may likewise enable them to colonize the phycosphere (Smriga et al, 2016;Raina et al, 2022).…”

Section: Organic Nutrition Preference and Environmental Pressure Adap...mentioning

confidence: 99%

“…The phycosphere is the key ecological interface for algaemicroorganism interactions (Seymour et al, 2017), and can be considered as marketplace where cross-kingdom communications are mediated by the release and uptake of organic compounds and gradients within this sphere guide chemoattraction of bacteria in microscale interactions (Ashraf et al, 2022). Thus, the size of the phycosphere is variable (several hundreds of micrometers to a few millimeters), depending largely on the size of algal cells and surrounding microbes, and can be changed by algal growth, exudation rate, concentration, and diffusivity of exuded compounds (Smriga et al, 2016;Seymour et al, 2017;Ashraf et al, 2022). Phycospheric microbial communities have highly complex and dynamic compositions, and variable ecological functions (Seymour et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

“…Phycospheric microorganisms exist in various forms; microorganisms in a free and particulate form are suspended in phycospheric seawater, while those in a flocculated form can build a zoogloea consortium to surround phytoplankton cells or build biofilms to attach to the macroalgal surface (Flemming et al, 2016). Recent research has revealed that the phycosphere contains many new and undiscovered microbial lineages and genetic resources (Zhang et al, 2019a;Ashraf et al, 2022). The formation of phycosphere microbial communities are closely related to algal bloom events and phycospheric microorganisms can influence the fate and development of algal bloom cooperatively or competitively, providing a new theory to analyze the mechanism of algal bloom occurrence (Zhou et al, 2018;Flemming and Wuertz, 2019;Liu et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

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Phycospheric bacterial community structure and function succession during the typical harmful macroalgal blooms

Hou

Chen

et al. 2022

Front. Mar. Sci.

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Based on the diversity and importance of phycospheric microorganisms as well as their complex interaction with algae, their ecological correlation with algal bloom events has become a research topic of great interest that remains unclear in the natural dynamic process of harmful macroalgal blooms (HMBs). The world’s largest green tides caused by macroalgae Ulva prolifera have occurred in the Yellow Sea for 16 consecutive years, and seriously affected the coastal ecosystem. Here, we monitored the spatiotemporal dynamics of the phycospheric bacterial community during the U. prolifera green tide bloom. The 73-day continuous field survey covered the whole process of initial invasion until the extinction of the green tide. The phycospheric bacterial community has a higher richness than the control seawater bacteria; in addition, it has more enriched taxa with organic nutrition preference and environmental pressure adaption, such as Bacteroidetes, Firmicutes, and Desulfobacterota. The same differences in populations and functional profiles were observed among the epiphytic bacterial and phycospheric seawater bacterial communities, which may be driven by the spatial heterogeneity of biogenic elements (e.g., organic nutrients and oxygen) among the habitats. Significant succession occurred in both the epiphytic bacterial and phycospheric seawater bacterial communities; their diversity and richness exhibited significant heterogeneity variation patterns, and their community structure became more similar in late phases. Our study revealed that macroalgal phycospheric microbial communities have a highly complex and dynamic composition and variable ecological functions, which indicate that phycospheric microorganisms are closely related to the fate of HMBs and may have the profound effect coastal biogeochemical cycles.

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“…In a microalgal–bacterial symbiotic biofilm, extracellular polymeric substances (EPS) play important roles in biosorption and biotransformation. , EPS’s multiple functional groups, including –COOH, –OH, –NH, –CONH, and –NH 3 + , enable the complexation of linear alkylbenzenesulfonates (LAS) and various species of nitrogen. ,− For the biological transformations of C and N, metabolic pathways involve uptake, dissimilation, assimilation, and mineralization steps catalyzed by multiple functional enzymes that are associated with the bacteria. ,,, According to a published stoichiometric analysis, 49% of C was removed by bacterial assimilation when acetate was the input organic, while microalgae and bacteria contributed to 25 and 59% of N removal, respectively . However, the mass flows of C and N in the symbiotic biofilms were not verified experimentally.…”

Section: Introductionmentioning

confidence: 99%

Mass Flow and Metabolic Pathway of Nonaeration Greywater Treatment in an Oxygenic Microalgal–Bacterial Biofilm

Zhou,

Wu,

Cui

et al. 2023

Environ. Sci. Technol.

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A symbiotic microalgal−bacterial biofilm can enable efficient carbon (C) and nitrogen (N) removal during aeration-free wastewater treatment. However, the contributions of microalgae and bacteria to C and N removal remain unexplored. Here, we developed a baffled oxygenic microalgal−bacterial biofilm reactor (MBBfR) for the nonaerated treatment of greywater. A hydraulic retention time (HRT) of 6 h gave the highest biomass concentration and biofilm thickness as well as the maximum removal of chemical oxygen demand (94.8%), linear alkylbenzenesulfonates (LAS, 99.7%), and total nitrogen (97.4%). An HRT of 4 h caused a decline in all of the performance metrics due to LAS biotoxicity. Most of C (92.6%) and N (95.7%) removals were ultimately associated with newly synthesized biomass, with only minor fractions transformed into CO 2 (2.2%) and N 2 (1.7%) on the function of multifarious-related enzymes in the symbiotic biofilm. Specifically, microalgae photosynthesis contributed to the removal of C and N at 75.3 and 79.0%, respectively, which accounted for 17.3% (C) and 16.7% (N) by bacteria assimilation. Oxygen produced by microalgae favored the efficient organics mineralization and CO 2 supply by bacteria. The symbiotic biofilm system achieved stable and efficient removal of C and N during greywater treatment, thus providing a novel technology to achieve low-energy-input wastewater treatment, reuse, and resource recovery.

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Synergy between microalgae and microbiome in polluted waters

Cited by 43 publications

References 92 publications

Microalgae as next generation plant growth additives: Functions, applications, challenges and circular bioeconomy based solutions

Microalgae as next generation plant growth additives: Functions, applications, challenges and circular bioeconomy based solutions

Phycospheric bacterial community structure and function succession during the typical harmful macroalgal blooms

Mass Flow and Metabolic Pathway of Nonaeration Greywater Treatment in an Oxygenic Microalgal–Bacterial Biofilm

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