Insights into the removal of antibiotics from livestock and aquaculture wastewater by algae-bacteria symbiosis systems.

With the burgeoning growth of the livestock and aquaculture industries, antibiotic residues in treated wastewater have become a serious ecological threat. Traditional biological wastewater treatment technologies-while effective for removing conventional pollutants, such as organic carbon, ammonia and phosphate-struggle to eliminate emerging contaminants, notably antibiotics. Recently, the use of microalgae has emerged as a sustainable and promising approach for the removal of antibiotics due to their non-target status, rapid growth and carbon recovery capabilities. This review aims to analyse the current state of antibiotic removal from wastewater using algae-bacteria symbiosis systems and provide valuable recommendations for the development of livestock/aquaculture wastewater treatment technologies. It (1) summarises the biological removal mechanisms of typical antibiotics, including bioadsorption, bioaccumulation, biodegradation and co-metabolism; (2) discusses the roles of intracellular regulation, involving extracellular polymeric substances, pigments, antioxidant enzyme systems, signalling molecules and metabolic pathways; (3) analyses the role of treatment facilities in facilitating algae-bacteria symbiosis, such as sequencing batch reactors, stabilisation ponds, membrane bioreactors and bioelectrochemical systems; and (4) provides insights into bottlenecks and potential solutions. This review offers valuable information on the mechanisms and strategies involved in the removal of antibiotics from livestock/aquaculture wastewater through the symbiosis of microalgae and bacteria.

Effects of microalgal (Tetradesmus obliquus MCX38) attachment on photobioreactor treatment efficiency of raw swine wastewater.

Attachment of microalgae on the inner surfaces of photobioreactors impacts the efficiency of swine wastewater treatment by reducing the light intensity, which has been overlooked in previous studies. This study investigated the relationship between microalgal attachment biomass and light intensity in photobioreactors, determined the optimal attachment time for effective pollutant removal, and clarified the mechanisms of microalgal attachment in swine wastewater. After 9 days of treatment, the attached biomass in the photobioreactor increased from 0 to 6.4 g/m2, decreasing the light intensity from 2,000 to 936 lux. At the 24 h optimal attachment time, the concentrations of chemical oxygen demand, ammonia nitrogen, and total phosphorus decreased from 2725.1, 396.4, and 87.2 mg/L to 361.2, 4.9, and 0.8 mg/L, respectively. Polysaccharides in the extracellular polymeric substances released by microalgae play a significant role in facilitating microalgae attachment. Optimizing the microalgal attachment time within photobioreactors effectively mitigates pollutant concentrations in swine wastewater.

Enhancing biomass conversion to bioenergy with machine learning: Gains and problems.

The growing concerns about environmental sustainability and energy security, such as exhaustion of traditional fossil fuels and global carbon footprint growth have led to an increasing interest in alternative energy sources, especially bioenergy. Recently, numerous scenarios have been proposed regarding the use of bioenergy from different sources in the future energy systems. In this regard, one of the biggest challenges for scientists is managing, modeling, decision-making, and future forecasting of bioenergy systems. The development of machine learning (ML) techniques can provide new opportunities for modeling, optimizing and managing the production, consumption and environmental effects of bioenergy. However, researchers in bioenergy fields have not widely utilized the ML concepts and practices. Therefore, a comparative review of the current ML techniques used for bioenergy productions is presented in this paper. This review summarizes the common issues and difficulties existing in integrating ML with bioenergy studies, and discusses and proposes the possible solutions. Additionally, a detailed discussion of the appropriate ML application scenarios is also conducted in every sector of the entire bioenergy chain. This indicates the modernized conversion processes supported by ML techniques are imperative to accurately capture process-level subtleties, and thus improving techno-economic resilience and socio-ecological integrity of bioenergy production. All the efforts are believed to help in sustainable bioenergy production with ML technologies for the future.

One-step synthesis of a core-shell structured biochar using algae (Chlorella) powder and ferric sulfate for immobilizing Hg(II).

Mercury (Hg) pollution poses a significant environmental challenge. One promising method for its removal is the sorption of mercuric ions using biochar. FeS-doped biochar (FBC) exhibits effective mercury adsorption, however may release excess iron into the surrounding water. To address this issue, a novel magnetic pyrrhotite/magnetite-doped biochar with a core-shell structure was synthesized for the adsorption of 2-valent mercury (Hg(II)). The proposed synthesis process involved the use of algae powder and ferric sulfate in a one-step method. By varying the ratio of ferric sulfate and alga powder (within the range of 0.18 - 2.5) had a notable impact on the composition of FBC. As the ferric sulfate content increased, the FBC exhibited a higher concentration of oxygen-containing groups. To assess the adsorption capacity, Langmuir and Freundlich adsorption models were applied to the experimental data. The most effective adsorption was achieved with FBC-4, reaching a maximum capacity (Qm) of 95.51 mg/g. In particular, at low Hg(II) concentrations, FBC-5 demonstrated the ability to reduce Hg(II) concentrations to less than 0.05 mg/L within 30 min. Additionally, the stability of FBC was confirmed within the pH range of 3.8 - 7.2. The study also introduced a model to analyze the adsorption preference for different Hg(II) species. Calomel was identified in the mercury saturated FBC, whereas the core-shell structure exhibited excellent conductivity, which most likely contributed to the minimal release of iron. In summary, this research presents a novel and promising method for synthesizing core-shell structured biochar and provides a novel approach to explore the adsorption contribution of different metal species.

Photocatalytic Optical Hollow Fiber with Enhanced Visible-light-driven CO2 Reduction.

A visible-light-driven CO2 reduction optical fiber is fabricated using graphene-like nitrogen-doped composites and hollow quartz optical fibers to achieve enhanced activity, selectivity, and light utilization for CO2 photoreduction. The composites are synthesized from a lead-based metal-organic framework (TMOF-10-NH2 ) and g-C3 N4 nanosheet (CNNS) via electrostatic self-assembly. The TMOF-10-NH2 /g-C3 N4 (TMOF/CNNS) photocatalyst with an S-type heterojunction is coated on optical fiber. The TMOF/CNNS coating, which has a bandgap energy of 2.15 eV, has good photoinduced capability at the coating interfaces, high photogenerated electron-hole pair yield, and high charge transfer rate. The conduction band potential of the TMOF/CNNS coating is more negative than that for CO2 reduction. Moreover, TMOF facilitates the CO desorption on its surface, thereby improving the selectivity for CO production. High CO2 photoreduction and selectivity for CO production is demonstrated by the TMOF/CNNS-coated optical fiber with the cladding/core diameter of 2000/1000 µm, 10 wt% TMOF in CNNS, coating thickness of 25 µm, initial CO2 concentration of 90 vol%, and relative humidity of 88% RH under the excitation wavelength of 380-780 nm. Overall, the photocatalytic hollow optical fiber developed herein provides an effective and efficient approach for the enhancement of light utilization efficiency of photocatalysts and selective CO2 reduction.

Aeration-Free In Situ Fenton-like Reaction: Specific Adsorption and Activation of Oxygen on Heterophase Oxygen Vacancies.

Aeration accounts for 35-51% of the overall energy consumption in wastewater treatment processes and results in an annual energy consumption of 5-7.5 billion kWh. Herein, a solar-powered continuous-flow device was designed for aeration-free in situ Fenton-like reactions to treat wastewater. This system is based on the combination of TiO2-x/W18O49 featuring heterophase oxygen vacancy interactions with floating reduced graphene/polyurethane foam, which produces hydrogen peroxide in situ at the rates of up to 4.2 ppm h-1 with degradation rates of more than 90% for various antibiotics. The heterophase oxygen vacancies play an important role in the stretching of the O-O bond by regulating the d-band center of TiO2-x/W18O49, promoting the hydrogenation of *·O2- or *OOH by H+ enrichment, and accelerating the production of reactive oxygen species by spontaneous adsorption of hydrogen peroxide. Furthermore, the degradation mechanisms of antibiotics and the treatment of actual wastewater were thoroughly investigated. In short, the study provides a meaningful reference for potentially undertaking the "aeration-free" in situ Fenton reaction, which can help reduce or even completely eradicate the aeration costs and energy requirements during the treatment of wastewater.

Advanced wastewater treatment with microalgae-indigenous bacterial interactions.

Microalgal-indigenous bacterial wastewater treatment (MBWT) emerges as a promising approach for the concurrent removal of nitrogen (N) and phosphorus (P). Despite its potential, the prevalent use of MBWT in batch systems limits its broader application. Furthermore, the success of MBWT critically depends on the stable self-adaptation and synergistic interactions between microalgae and indigenous bacteria, yet the underlying biological mechanisms are not fully understood. Here we explore the viability and microbial dynamics of a continuous flow microalgae-indigenous bacteria advanced wastewater treatment system (CFMBAWTS) in processing actual secondary effluent, with a focus on varying hydraulic retention times (HRTs). The research highlights a stable, mutually beneficial relationship between indigenous bacteria and microalgae. Microalgae and indigenous bacteria can create an optimal environment for each other by providing essential cofactors (like iron, vitamins, and indole-3-acetic acid), oxygen, dissolved organic matter, and tryptophan. This collaboration leads to effective microbial growth, enhanced N and P removal, and energy generation. The study also uncovers crucial metabolic pathways, functional genes, and patterns of microbial succession. Significantly, the effluent NH4+-N and P levels complied with the Chinese national Class-II, Class-V, Class-IA, and Class-IB wastewater discharge standards when the HRT was reduced from 15 to 6 h. Optimal results, including the highest rates of CO2 fixation (1.23 g L-1), total energy yield (32.35 kJ L-1), and the maximal lipid (33.91%) and carbohydrate (41.91%) content, were observed at an HRT of 15 h. Overall, this study not only confirms the feasibility of CFMBAWTS but also lays a crucial foundation for enhancing our understanding of this technology and propelling its practical application in wastewater treatment plants.

Adsorption performance of Ni(II) by KOH-modified biochar derived from different microalgae species.

Microalgae biochar is potential adsorbents to remove heavy metals from wastewater due to abundant functional groups, high porosity and wide sources, but performance is not fully developed since it depends on microalgae species attributing to distinct morphology and biomass compositions. Here, two microalgae species Chlorella Pyrenoidosa and Scenedesmus Obliquus were used for biochar preparation via KOH-modification, biochar properties and their influences on Ni(II) adsorption were investigated. Ni(II) adsorption performances responding to biochar properties and operating conditions were upgraded via progressive optimization and response surface methodology. Together, adsorption isotherms and kinetics were analyzed to obtain significant factors for Ni(II) removal. As results, 100 % of Ni(II) removal was achieved under 100 mg/L initial Ni(II) concentration as pH was higher than the biochar zero-charge point of 6.87 with low biochar dosage (0.5 g/L), which provides an efficient approach for heavy metal removal from wastewater with microalgae biochar.

Cytoprotective alginate microcapsule serves as a shield for microalgal encapsulation defensing sulfamethoxazole threats and safeguarding nutrient recovery.

Microalgal encapsulation technology is expected to broaden more possibilities for employing microalgae for upgrading conventional biological wastewater treatment. However, only limited and fragmented information is currently available on microalgal encapsulation and pollutant removal. It is ambiguous whether it hold potential for wastewater treatment. Particularly, it remains to be determined whether this technology can provide more possibilities in harsh sewage environments. Here, potential of encapsulated technology to recover nutrients from wastewater was examined, simultaneously compared with commonly adopted suspended system. Results indicate the encapsulated microalgal system showed outstanding advantages in nutrient recovery and defense against antibiotic threats. Moreover, by examining the cellular oxidative stress response and changes of the photosynthetic system, the encapsulated system exhibited potential cytoprotective advantages to microalgal cells for defensing antibiotic threats. Molecular dynamics simulation revealed that the differences among superficial aggregation between the nutrients' ions and molecular sulfamethoxazole on the cross-linked alginate microcapsule surface dominated the nutrient recovery and cytoprotective functions. Ultimately, the molecular nature of pollutants was found to be the most critical aspect for predicting application of this microalgal microcapsule. Cytoprotective systems created with alginate microcapsules can potentially handle more diverse threats with a single type of surface charge in their outermost layer.

Insights into the role of extracellular polymeric substances (EPS) in the spread of antibiotic resistance genes.

Antibiotic resistance genes (ARG) are prevalent in aquatic environments. Discharge from wastewater treatment plants is an important point source of ARG release into the environment. It has been reported that biological treatment processes may enhance rather than remove ARG because of their presence in sludge. Attenuation of ARG in biotechnological processes has been studied in depth, showing that many microorganisms can secrete complex extracellular polymeric substances (EPS). These EPS can serve as multifunctional elements of microbial communities, involving aspects, such as protection, structure, recognition, adhesion, and physiology. These aspects can influence the interaction between microbial cells and extracellular ARG, as well as the uptake of extracellular ARG by microbial cells, thus changing the transformative capability of extracellular ARG. However, it remains unclear whether EPS can affect horizontal ARG transfer, which is one of the main processes of ARG dissemination. In light of this knowledge gap, this review provides insight into the role of EPS in the transmission of ARGs; furthermore, the mechanism of ARG spread is analyzed, and the molecular compositions and functional properties of EPS are summarized; also, how EPS influence ARG mitigation is addressed, and factors impacting how EPS facilitate ARG during wastewater treatment are summarized. This review provides comprehensive insights into the role of EPS in controlling the transport and fate of ARG during biodegradation processes at the mechanistic level.

Sustainable Seawater Desalination and Energy Management: Mechanisms, Strategies, and the Way Forward.

Solar-driven desalination systems have been recognized as an effective technology to address the water crisis. Recently, evaporators prepared based on advanced manufacturing technologies have emerged as a promising tool in enhancing ocean energy utilization. In this review, we discussed the thermal conversion, energy flow, salt deposition mechanisms, and design strategies for solar-driven desalination systems, and explored how to improve the desalination performance and energy use efficiency of the systems through advanced manufacturing technologies. In future perspectives, we determined the feasibility of coupling solar-driven solar desalination systems with multi-stage energy utilization systems and emerging artificial intelligence technologies, for which conclusions are given and new directions for future desalination system development are envisioned. Finally, exciting opportunities and challenges in the face of basic research and practical implementation are discussed, providing promising solutions and blueprints for green and novel desalination technologies while achieving sustainable development.

Construction of highly dispersed iron active sites for efficient catalytic ozonation of bisphenol A.

The essential factor of catalytic ozonation technology relies on an efficient and stable catalyst. The construction of highly dispersed active sites on heterogeneous catalysts is an ideal strategy to combine the merits of homogeneous and heterogeneous catalysis with high activity and stability. Herein, an iron-containing mesoporous silica material (Fe-SBA15) with sufficient iron site exposure and enhanced intrinsic activity of active sites was employed to activate ozone for bisphenol A (BPA) degradation. Approximately 100% of BPA and 36.6% of total organic carbon (TOC) removal were realized by the Fe-SBA15 catalytic ozonation strategy with a reaction constant of 0.076 min-1, well beyond the performance of FeOx/SBA15 mixture and Fe2O3. Radical quenching experiments and electron paramagnetic resonance (EPR) analysis demonstrated that the hydroxyl radicals (HO•) and superoxide radicals (O2•-) played an important role in the degradation process. The iron sites with recyclable Fe(III)/Fe(II) pairs act as both the electron donors and active sites for catalytic ozonation. The mesoporous framework of SBA15 in Fe-SBA15 stabilizes the iron sites that enhance its stability. With high catalytic performance and high reusability for catalytic ozonation of BPA, the Fe-SBA15 is expected to be a promising catalyst in catalytic ozonation for wastewater treatment.

The magic of algae-based biochar: advantages, preparation, and applications.

Compared with other biomass sources, the use of algae as a raw material to prepare biochar (BC) has important advantages including safety, high yield and economy. The protein content of algae cells is as high as 3.2 mg DCW/L, and the graphitic-N and N-O functional groups generated by the pyrolysis of proteins could effectively activate free radicals. Combined with the generated pore structure, the electron transfer/exchange capability was enhanced, which is conducive to improving its catalytic performance. Algae as a natural N source, the manuscript analyzed the surface properties and physicochemical properties of algae-based BC, and investigated its degradation effect on organic/inorganic pollutants in wastewater. Subsequently, the effect of nitrogen-doped BC on the adsorption/catalysis capacity was discussed. Finally, the directed preparation of algae-based BC applied in different scenarios was summarized. Algae-based BC has the property of N doping, which broadens its application efficiency in the environmental field. Overall, this manuscript reviews how to achieve efficient utilization of algae-based BC in wastewater.

Toxin type and domain sequence affect accumulation of recombinant immunotoxins.Transient expression in plant cell packs and intact plants correlates well.IC50 values of toxicity correlate with the cell surface receptor concentration.

Metabonomics analysis of microalga Scenedesmus obliquus under ciprofloxacin stress.

The wide use of antibiotics in aquaculture has triggered global ecological security issue. Microalgal bioremediation is a promising strategy for antibiotics elimination due to carbon recovery, detoxification and various ecological advantages. However, a lack of understanding with respect to the corresponding regulation mechanism towards antibiotic stress may limit its practical applicability. The microalga Scenedesmus obliquus was shown to be capable of effectively eliminating ciprofloxacin (CIP), which is a common antibiotic used in aquaculture. However, the corresponding transcriptional alterations require further investigation and verification at the metabolomic level. Thus, this study uncovered the metabolomic profiles and detailed toxic and defense mechanisms towards CIP in S. obliquus using untargeted metabolomics. The enhanced oligosaccharide/polyol/lipid transport, up-regulation of carbohydrate and arachidonic acid metabolic pathways and increased energy production via EMP metabolism were observed as defense mechanisms of microalgal cells to xenobiotic CIP. The toxic metabolic responses included: (1) down-regulation of parts of mineral and organic transporters; (2) electrons competition between antibiotic and NAD during intracellular CIP degradation; and (3) suppressed expression of the hem gene in chlorophyll biosynthesis. This study describes the metabolic profile of microalgae during CIP elimination and reveals the key pathways from the perspective of metabolism, thereby providing information on the precise regulation of antibiotic bioremediation via microalgae.

Tetracycline-adsorbed biochar for solid biofuel usage to achieve waste utilization for environmental sustainability.

Biochar is widely used to remove organic pollutants from the environment. Several studies have focused on pollutant removal via biochar adsorption. However, research on the subsequent processing of pollutant-adsorbed biochar is lacking. This study explored the potential of biochar for the adsorption of an aquatic organic pollutant (tetracycline) and its subsequent use as a solid biofuel. These results suggest that corn straw-derived biochar (torrefaction and pyrolysis) is suitable for two-stage utilization to achieve bioresource valorization for environmental sustainability. Tetracycline-adsorbed biochar, particularly biochar pyrolyzed at 600 °C, is suitable for use as a biofuel. The biochar produced via torrefaction (300 °C) and pyrolysis (600 °C) is the optimal choice, with surface area, contact angle, graphitization degree, calorific value, enhancement factor, and upgrading energy index values of 172.48 m2/g, 120.4°, 3.87, 26.983 MJ/kg, 1.58, and 33.72, respectively. This is supported by the results of expense calculation, comprehensive performance analysis, and life-cycle assessment. Overall, the biochar produced in this study is suitable for organic pollutant removal and as solid biofuel; thus, it can be used to realize waste utilization for environmental sustainability.

Comprehensive insights into antibiotic resistance gene migration in microalgal-bacterial consortia: Mechanisms, factors, and perspectives.

With the overuse of antibiotics, antibiotic resistance gene (ARG) prevalence is gradually increasing. ARGs are considered emerging contaminants that are broadly concentrated and dispersed in most aquatic environments. Recently, interest in microalgal-bacterial biotreatment of antibiotics has increased, as eukaryotes are not the primary target of antimicrobial drugs. Moreover, research has shown that microalgal-bacterial consortia can minimize the transmission of antibiotic resistance in the environment. Unfortunately, reviews surrounding the ARG migration mechanism in microalgal-bacterial consortia have not yet been performed. This review briefly introduces the migration of ARGs in aquatic environments. Additionally, an in-depth summary of horizontal gene transfer (HGT) between cyanobacteria and bacteria and from bacteria to eukaryotic microalgae is presented. Factors influencing gene transfer in microalgal-bacterial consortia are discussed systematically, including bacteriophage abundance, environmental conditions (temperature, pH, and nutrient availability), and other selective pressure conditions including nanomaterials, heavy metals, and pharmaceuticals and personal care products. Furthermore, considering that quorum sensing could be involved in DNA transformation by affecting secondary metabolites, current knowledge surrounding quorum sensing regulation of HGT of ARGs is summarized. In summary, this review gives valuable information to promote the development of practical and innovative techniques for ARG removal by microalgal-bacterial consortia.

Comparative advantages analysis of oxidative torrefaction for solid biofuel production and property upgrading.

This study performs the comparative advantage analysis of oxidative torrefaction of corn stalks to investigate the advantages of oxidative torrefaction for biochar fuel property upgrading. The obtained results indicate that oxidative torrefaction is more efficient in realizing mass loss and energy density improvement, as well as elemental carbon accumulation and surface functional groups removal, and thus leads to a better fuel property. The maximum values of relative mass loss, higher heating value, enhancement factor, and energy yield are 3.00, 1.10, 1.03, and 0.87, respectively. The relative elemental carbon, hydrogen, and oxygen content ranges are 1.30-3.10, 1.50-3.30, and 2.00-6.80, respectively. In addition, an excellent linear distribution is obtained between the comprehensive pyrolysis index and torrefaction severity index, with elemental carbon and oxygen component variation stemming from pyrolysis performance correlating to the elemental component and valance.

New insight into the concentration-dependent removal of multiple antibiotics by Chlorella sorokiniana.

Microalgae have attracted increasing attention as an environmentally friendly treatment for antibiotics. However, the effect of antibiotic concentration on the removal ability of microalgae with the underlying mechanisms remains unclear. Thus, this work investigates the removal of tetracycline (TET), sulfathiazole (STZ), and ciprofloxacin (CIP) at different concentrations using Chlorella sorokiniana. The results indicate that microalgae have a concentration-dependent effect on antibiotic removal; however, the removal trends for the three antibiotics differed significantly. Specifically, TET showed nearly 100% removal efficiency at any concentration. The high concentration of STZ inhibited microalgal photosynthesis and induced the production of ROS, leading to antioxidant damage and inhibiting removal efficiency. Conversely, CIP enhanced the ability of microalgae to remove CIP by inducing a dual peroxidase and cytochrome p450 enzyme response. Furthermore, the economic analysis demonstrated that microalgae treatment antibiotics were calculated to be 4.93€/m3, which becomes cheaper than the other microalgae water treatment process.

Functional Characterization of Lycopene ß- and ε-Cyclases from a Lutein-Enriched Green Microalga Chlorella sorokiniana FZU60.

Lutein is a high-value carotenoid with many human health benefits. Lycopene ß- and ε-cyclases (LCYB and LCYE, respectively) catalyze the cyclization of lycopene into distinct downstream branches, one of which is the lutein biosynthesis pathway, via α-carotene. Hence, LCYB and LCYE are key enzymes in lutein biosynthesis. In this study, the coding genes of two lycopene cyclases (CsLCYB and CsLCYE) of a lutein-enriched marine green microalga, Chlorella sorokiniana FZU60, were isolated and identified. A sequence analysis and computational modeling of CsLCYB and CsLCYE were performed using bioinformatics to identify the key structural domains. Further, a phylogenetic analysis revealed that CsLCYB and CsLCYE were homogeneous to the proteins of other green microalgae. Subcellular localization tests in Nicotiana benthamiana showed that CsLCYB and CsLCYE localized in chloroplasts. A pigment complementation assay in Escherichia coli revealed that CsLCYB could efficiently ß-cyclize both ends of lycopene to produce ß-carotene. On the other hand, CsLCYE possessed a strong ε-monocyclase activity for the production of δ-carotene and a weak ε-bicyclic activity for the production of ε-carotene. In addition, CsLCYE was able to catalyze lycopene into ß-monocyclic γ-carotene and ultimately produced α-carotene with a ß-ring and an ε-ring via γ-carotene or δ-carotene. Moreover, the co-expression of CsLCYB and CsLCYE in E. coli revealed that α-carotene was a major product, which might lead to the production of a high level of lutein in C. sorokiniana FZU60. The findings provide a theoretical foundation for performing metabolic engineering to improve lutein biosynthesis and accumulation in C. sorokiniana FZU60.

Simultaneously enhancement in the assimilation of microalgal nitrogen and the accumulation of carbohydrate by Debaryomyces hansenii.

Microalgae-based techniques are considered an alternative to traditional activated sludge processes for removing nitrogen from wastewater. Bacteria consortia have been broadly conducted as one of the most important partners. However, fungal effects on the removal of nutrients and changes in physiological properties of microalgae, and their impact mechanisms remain unclear. The current work demonstrates that, adding fungi increased the nitrogen assimilation of microalgae and the generation of carbohydrates compared to pure microalgal cultivation. The NH4+-N removal efficiency was 95.0% within 48 h using the microalgae-fungi system. At 48 h, total sugars (glucose, xylose, and arabinose) accounted for 24.2 ± 4.2% per dry weight in the microalgae-fungi group. Gene ontology (GO) enrichment analysis revealed that, among various processes, phosphorylation and carbohydrate metabolic processes were more prominent. Gene encoding the key enzymes of glycolysis, pyruvate kinase, and phosphofructokinase were significantly up-regulated. Overall, for the first time, this study provides new insights into the art of microalgae-fungi consortia for producing value-added metabolites.