Unraveling the shift in bacterial communities profile grown in sediments co-contaminated with chlorolignin waste of pulp-paper mill by metagenomics approach.

Pulp-paper mills (PPMs) are known for consistently generating a wide variety of pollutants, that are often unidentified and highly resistant to environmental degradation. The current study aims to investigate the changes in the indigenous bacterial communities profile grown in the sediment co-contaminated with organic and inorganic pollutants discharged from the PPMs. The two sediment samples, designated PPS-1 and PPS-2, were collected from two different sites. Physico-chemical characterization of PPS-1 and PPS-2 revealed the presence of heavy metals (mg kg-1) like Cu (0.009-0.01), Ni (0.005-0.002), Mn (0.078-0.056), Cr (0.015-0.009), Pb (0.008-0.006), Zn (0.225-0.086), Fe (2.124-0.764), Al (3.477-22.277), and Ti (99.792-45.012) along with high content of chlorophenol, and lignin. The comparative analysis of organic pollutants in sediment samples using gas chromatography-mass spectrometry (GC-MS) revealed the presence of major highly refractory compounds, such as stigmasterol, ß-sitosterol, hexadecanoic acid, octadecanoic acid; 2,4-di-tert-butylphenol; heptacosane; dimethyl phthalate; hexachlorobenzene; 1-decanol,2-hexyl; furane 2,5-dimethyl, etc in sediment samples which are reported as a potential toxic compounds. Simultaneously, high-throughput sequencing targeting the V3-V4 hypervariable region of the 16S rRNA genes, resulted in the identification of 1,249 and 1,345 operational taxonomic units (OTUs) derived from a total of 115,665 and 119,386 sequences read, in PPS-1 and PPS-2, respectively. Analysis of rarefaction curves indicated a diversity in OTU abundance between PPS-1 (1,249 OTUs) and PPS-2 (1,345 OTUs). Furthermore, taxonomic assignment of metagenomics sequence data showed that Proteobacteria (55.40%; 56.30%), Bacteoidetes (11.30%; 12.20%), and Planctomycetes (5.40%; 4.70%) were the most abundant phyla; Alphproteobacteria (20.50%; 23.50%), Betaproteobacteria (16.00%; 12.30%), and Gammaproteobacteria were the most recorded classes in PPS-1 and PPS-2, respectively. At the genus level, Thiobacillus (7.60%; 4.50%) was the most abundant genera grown in sediment samples. The results indicate significant differences in both the diversity and relative abundance of taxa in the bacterial communities associated with PPS-2 when compared to PPS-1. This study unveils key insights into contaminant characteristics and shifts in bacterial communities within contaminated environments. It highlights the potential for developing efficient bioremediation techniques to restore ecological balance in pulp-paper mill waste-polluted areas, stressing the importance of identifying a significant percentage of unclassified genera and species to explore novel genes.

Sub-pilot scale sequential microalgal consortium-based cultivation for treatment of municipal wastewater and biomass production.

Municipal wastewater (MWW) was treated by a sequential pilot microalgal cultivation process. The cultivation was performed inside a specifically designed low-cost photobioreactor (PBR) system. A microalgal consortium 2:1 was developed using Tetraselmis indica (TS) and Picochlorum sp. (PC) in the first stage and PC:TS (2:1) in the second stage and the nutrient removal efficiency and biomass production and biomolecules production was evaluated and also compared with monoculture in a two-stage sequential cultivation system. This study also investigated the effect of seasonal variations on microalgae growth and MWW treatment. The results showed that mixed microalgal consortium (TS:PC) had higher nutrient removal efficiency, with chemical oxygen demand (COD), total phosphate (TP), and total nitrate (TN) removal efficiencies of 78.50, 84.49, and 84.20%, respectively, and produced a biomass of 2.50 g/L with lipid content of 37.36% in the first stage of cultivation under indoor conditions. In the second stage of indoor cultivation, the PC:TS consortium demonstrated maximum COD, TP, and TN removal efficiencies of 92.49, 94.24, and 94.16%, respectively. It also produced a biomass of 2.65 g/L with a lipid content of 40.67%. Among all the seasonal variations, mass flow analysis indicated that the combination of mixed consortium-based two-stage sequential process during the winter season favored maximum nutrient removal efficiency of TN i.e. 88.54% (84.12 mg/L) and TP i.e., 90.18% (43.29 mg/L), respectively. It also enhanced total biomass production of 49.10 g in 20-L medium, which includes lipid yield ∼15.68 g compared to monoculture i.e., 82.06% (78.70 mg/L) and 82.87% (40.26 mg/L) removal of TN and TP, respectively, and produced biomass 43.60 g with 11.90 g of lipids.

Exploring the association between long-term MODIS aerosol and air pollutants data across the Northern Great Plains through machine learning analysis.

Aerosol optical depth (AOD) and Ångström exponent (AE) are the major environmental indicators to perceive air quality and the impact of aerosol on climate change and health as well as the global atmospheric conditions. In the present study, an average of AOD and AE data from Tera and Aqua satellites of MODIS sensors has been investigated over 7 years i.e., from 2016 to 2022, at four locations over Northern Great Plains. Both temporal and seasonal variations over the study periods have been investigated to understand the behavior of AOD and AE. Over the years, the highest AOD and AE were observed in winter season, varying from 0.75 to 1.17 and 1.30 to 1.63, respectively. During pre-monsoon season, increasing trend of AOD varying from 0.65 to 0.95 was observed from upper (New Delhi) to lower (Kolkata) Gangetic plain, however, during monsoon and post-monsoon a reverse trend varying from 0.85 to 0.65 has been observed. Seasonal and temporal aerosol characteristics have also been analyzed and it has been assessed that biomass burning was found to be the major contributor, followed by desert dust at all the locations except in Lucknow, where the second largest contributor was dust instead of desert dust. During season-wise analysis, biomass burning was also found to be as the major contributor at all the places in all the seasons except New Delhi and Lucknow, where dust was the major contributor during pre-monsoon. A boosting regression algorithm was done using machine learning to explore the relative influence of different atmospheric parameters and pollutants with PM2.5. Water vapor was assessed to have the maximum relative influence i.e., 51.66 % followed by CO (21.81 %). This study aims to help policy makers and decision makers better understand the correlation between different atmospheric components and pollutants and the contribution of different types of aerosols.

Advances in microalgae-based carbon sequestration: Current status and future perspectives.

The advancement in carbon dioxide (CO2) sequestration technology has received significant attention due to the adverse effects of CO2 on climate. The mitigation of the adverse effects of CO2 can be accomplished through its conversion into useful products or renewable fuels. In this regard, microalgae is a promising candidate due to its high photosynthesis efficiency, sustainability, and eco-friendly nature. Microalgae utilizes CO2 in the process of photosynthesis and generates biomass that can be utilized to produce various valuable products such as supplements, chemicals, cosmetics, biofuels, and other value-added products. However, at present microalgae cultivation is still restricted to producing value-added products due to high cultivation costs and lower CO2 sequestration efficiency of algal strains. Therefore, it is very crucial to develop novel techniques that can be cost-effective and enhance microalgal carbon sequestration efficiency. The main aim of the present manuscript is to explain how to optimize microalgal CO2 sequestration, integrate valuable product generation, and explore novel techniques like genetic manipulations, phytohormones, quantum dots, and AI tools to enhance the efficiency of CO2 sequestration. Additionally, this review provides an overview of the mass flow of different microalgae and their biorefinery, life cycle assessment (LCA) for achieving net-zero CO2 emissions, and the advantages, challenges, and future perspectives of current technologies. All of the reviewed approaches efficiently enhance microalgal CO2 sequestration and integrate value-added compound production, creating a green and economically profitable process.

Microalgae: A potential bioagent for treatment of emerging contaminants from domestic wastewater.

Water crisis around the world leads to a growing interest in emerging contaminants (ECs) that can affect human health and the environment. Research showed that thousands of compounds from domestic consumers, such as endocrine disrupting chemicals (EDCs), personal care products (PCPs), and pharmaceuticals active compounds (PhAcs), could be found in wastewater in concentration mostly from ng L-1 to µg L-1. However, generally, wastewater treatment plants (WWTPs) are not designed to remove these ECs from wastewater to their discharge levels. Scientists are looking for economically feasible biotreatment options enabling the complete removal of ECs before discharge. Microalgae cultivation in domestic wastewater is likely a feasible approach for removing emerging contaminants and simultaneously removing any residual organic nutrients. Microalgal growth rate and contaminants removal efficiency could be affected by various factors, including light intensity, CO2 addition, presence of different nutrients, etc., and these parameters could greatly help make microalgae treatment more efficient. Furthermore, the algal biomass harvests could be repurposed to produce various bulk chemicals such as sustainable aviation fuel, biofuel, bioplastic, and biochar; this could significantly enhance the economic viability. Therefore, this review summarizes the microalgae-based bioprocess and their mechanisms for removing different ECs from different wastewaters and highlights the different strategies to improve the ECs removal efficiency. Furthermore, this review shows the role of different ECs in biomass profile and the relevance of using ECs-treated microalgae biomass to produce green products, as well as highlights the challenges and future research recommendations.

Pulp-paper industry sludge waste biorefinery for sustainable energy and value-added products development: A systematic valorization towards waste management.

The pulp-paper industry is one of the main industrial sectors that produce massive amounts of residual sludge, constituting an enormous environmental burden for the industries. Traditional sludge management practices, such as landfilling and incineration, are restricted due to mounting environmental pressures, complex regulatory frameworks, land availability, high costs, and public opinion. Valorization of pulp-paper industry sludge (PPS) to produce high-value products is a promising substitute for traditional sludge management practices, promoting their reuse and recycling. Valorization of PPIS for biorefinery beneficiation includes biomethane, biohydrogen, bioethanol, biobutanol, and biodiesel production for renewable energy generation. Additionally, the various thermo-chemical technologies can be utilized to synthesize bio-oil, hydrochar, biochar, adsorbent, and activated carbon, signifying potential for value-added generation. Moreover, PPIS can be recycled as a byproduct by incorporating it into nanocomposites, cardboard, and construction materials development. This paper aims to deliver a comprehensive overview of PPIS management approaches and thermo-chemical technologies utilized for the development of platform chemicals in industry. Substitute uses of PPIS, such as making building materials, developing supercapacitors, and making cardboard, are also discussed. In addition, this article deeply discusses recent developments in biotechnologies for valorizing PPIS to yield an array of valuable products, such as biofuels, lactic acids, cellulose, nanocellulose, and so on. This review serves as a roadmap for future research endeavors in the effective handling of PPIS.

Neurotensin receptor-1 antagonist SR48692 modulation of high-fat diet induced reproductive impairment in male mice.

Neurotensin (NTS), a tridecapeptide of the gastrointestinal tract, has been implicated in the facilitation of lipid absorption on ingestion of a high-fat diet (HFD) especially via NTS receptors, NTSR1, NTSR2, and NTSR3, to cause lipid metabolic dysregulation and imbalance of the oxidant-antioxidant system. Oxidative stress induced a negative impact on reproductive function, affecting the reproductive organ and related reproductive hormones. The present study elucidated the efficacy of NTSR1 antagonist SR48692 in the modulation of HFD-induced reproductive impairment in male mice. Swiss albino mice (male, 23 ± 2 g) were maintained (6/group) for eight weeks; Group-I chow diet (CD), Group-II HFD, Group-III (HFD+SR48692L), Group-IV (HFD+SR48692H), Group-V (CD+SR48692L) and Group-VI (CD+SR48692H). SR48692 low (100 µg/kg b.w./SR48692L) and high-dose (400 µg/kg b.w./SR48692H) were given intraperitoneally for the last four weeks. Treatment with low-dose (SR48692L) to HFD-fed mice showed some efficacy in mitigating lipid dysregulation, oxidative stress, and reproductive impairment as evidenced by decreased triglycerides, total cholesterol, low-density lipoprotein cholesterol, leptin, and increased high-density lipoprotein cholesterol, increased antioxidant defense enzymes, reduction of histopathological scores in testis and increase in plasma level of LH, FSH and testosterone compared to that of HFD, but not up to CD. With the high-dose of antagonist (SR48692H) showed more adverse effects even from that of HFD. Treatment of both doses of SR48692 to CD-fed mice these effects become more extended. Less effectiveness of NTSR1 antagonist with the doses tried (low and high) in normalizing the lipid dysregulation and reproductive impairments might be due to the persistence of NTSR2/NTSR3-mediated lipid absorption.

Functionalization of MWCNTs for Bioelectrocatalysis by Bacterial Two-Domain Laccase from Catenuloplanes japonicus.

This study was carried out in order to assess several modifications of carbon nanotube-based nanomaterials for their applications in laccase electrodes and model biofuel cells. The modified MWCNTs served as adapters for the immobilization of laccase from Catenuloplanes japonicus VKM Ac-875 on the surface of electrodes made of graphite rods and graphite paste. The electrochemical properties of the electrodes were tested in linear and cyclic voltammetrical measurements for the determination of the redox potential of the enzyme and achievable current densities. The redox potential of the enzyme was above 500 mV versus NHE, while the highest current densities reached hundreds of µA/cm2. Model biofuel cells on the base of the laccase cathodes had maximal power values from 0.4 to 2 µW. The possibility of practical application of such BFCs was discussed.

A critical review on environmental risk and toxic hazards of refractory pollutants discharged in chlorolignin waste of pulp and paper mills and their remediation approaches for environmental safety.

Agro-based pulp and paper mills (PPMs) inevitably produce numerous refractory pollutants in their wastewater, including chlorolignin, chlorophenols, chlorocatechols, chloroguaiacol, cyanide, furan, dioxins, and other organic compounds, as well as various heavy metals, such as nickel (Ni), zinc (Zn), chromium (Cr), iron (Fe), lead (Pb), arsenic (As), etc. These pollutants pose significant threats to aquatic and terrestrial life due to their cytogenotoxicity, mutagenicity, impact on sexual organs, hormonal interference, endocrine disruption, and allergenic response. Consequently, it is crucial to reclaim pulp paper mill wastewater (PPMW) with high loads of refractory pollutants through effective and environmentally sustainable practices to minimize the presence of these chemicals and ensure environmental safety. However, there is currently no comprehensive published review providing up-to-date knowledge on the fate of refractory pollutants from PPMW in soil and aquatic environments, along with valuable insights into the associated health hazards and remediation methods. This critical review aims to shed light on the potential adverse effects of refractory pollutants from PPMW on natural ecosystems and living organisms. It explores existing effective treatment technologies for remediating these pollutants from wastewater, highlighting the advantages and disadvantages of each approach, all in pursuit of environmental safety. Special emphasis is placed on emerging technologies used to decontaminate wastewater discharged from PPMs, ensuring the preservation of the environment. Additionally, this review addresses the major challenges and proposes future research directions for the proper disposal of PPMW. It serves as a comprehensive source of knowledge on the environmental toxicity and risks associated with refractory pollutants in PPMW, making it a valuable reference for policymakers and researchers when selecting appropriate technologies for remediation. The scientific community, concerned with mitigating the widespread risks posed by refractory pollutants from PPMs, is expected to take a keen interest in this review.

Microbial assisted multifaceted amelioration processes of heavy-metal remediation: a clean perspective toward sustainable and greener future.

Rapidly increasing heavy metal waste has adversely affected the environment and the Earth's health. The lack of appropriate remediation technologies has worsened the issue globally, especially in developing countries. Heavy-metals contaminants have severely impacted the environment and led to devastating conditions owing to their abundance and reactivity. As they are nondegradable, the potential risk increases even at a low concentration. However, heavy-metal remediation has increased with the up-gradation of technologies and integration of new approaches. Also, of all the treatment methodologies, microbial-assisted multifaceted approach for ameliorating heavy metals is a promising strategy for propagating the idea of a green and sustainable environment with minimal waste aggregation. Microbial remediation combined with different biotechniques could aid in unraveling new methods for eradicating heavy metals. Thus, the present review focuses on various microbial remediation approaches and their affecting factors, enabling recapitulation of the interplay between heavy-metals ions and microorganisms. Additionally, heavy-metals remediation mechanisms adapted by microorganisms, the role of genetically modified (GM) microorganisms, life cycle assessment (LCA), techno-economic assessment (TEA) limitations, and prospects of microbial-assisted amelioration of heavy-metals have been elaborated in the current review with focus toward "sustainable and greener future."

Development of economical and sustainable cultivation system for biomass production and simultaneous treatment of municipal wastewater using Tetraselmis indica BDUG001.

Microalgal-based bioprocess offers several advantages including wastewater reclamations, therefore present study assessed the usability of the combination of untreated municipal sewage wastewater (UTMSWW) and secondary treated municipal sewage wastewater (STSWW) for nutrient removal and recovery by Tetraselmis indica (T. indica) BDUG001. The present study optimized the additional nutrient supplementations (e.g. ASN-III) percentage and day-night cycle, pH and pH with aeration for monitoring high-rate biomass production and nutrient recovery. The study results showed that the combination of 75% UTMSWW + 25% ASN-III supported maximum biomass production (2.65 ± 0.07 g/L). In the optimized day-night cycle (12:12 h), T. indica BDUG001 showed improved biomass production (2.75 ± 0.07 g/L), biomass productivity (165.63 ± 4.42 mg/L/d), and photosynthetic pigments production. Under optimized pH∼ 7.0 with aeration, maximum total nitrate (TN) removal efficiency (87.67 ± 3.08-91.55 ± 1.92%) was observed, while COD and TP removal was maximum at pH ∼ 9.0. The maximum biomass production (2.35 ± 0.07-2.77 ± 0.04 g/L) with biomass productivity (93.75 ± 167.19 ± 2.21 mg/L/d) and lipid content (42.98 ± 1.86-47.85 ± 0.21% DCW) were also at pH 7.0. with aeration. The present study verified the utilization of UTMSWW with the combination of conventional medium, optimized day-night cycle, pH with aeration along with designing low-cost PBR. It was the ideal system for the cultivation of T. indica BDUG001 for the recovery of nutrients from wastewater, production of biofuels and value-added feedstock.

Organosolv pretreatment: an in-depth purview of mechanics of the system.

The concept of biorefinery has been advancing globally and organosolv pretreatment strategy has seen an upsurge in research due to its efficiency in removing the recalcitrant lignin and dissolution of cellulose. The high-performance organosolv system uses green solvents and its reusability contributes concurrently to the biorefinery sector and sustainability. The major advantage of the current system involves the continuous removal of lignin to enhance cellulose accessibility, thereby easing the later biorefinery steps, which were immensely restricted due to the recalcitrant lignin. The current system process can be further explored and enhanced via the amalgamation of new technologies, which is still a work in progress. Thus, the current review summarizes organosolv pretreatment and the range of solvents used, along with a detailed mechanistic approach that results in efficient pretreatment of LCB. The latest developments for designing high-performance pretreatment systems, their pitfalls, and advanced assessments such as Life Cycle Assessment along with Techno-Economic Assessment have also been deliberated to allow an insight into its diverse potential applicability towards a sustainable future.

An insight into the principles of lignocellulosic biomass-based zero-waste biorefineries: a green leap towards imperishable energy-based future.

Lignocellulosic biomass (LCB) is an energy source that has a huge impact in today's world. The depletion of fossil fuels, increased pollution, climatic changes, etc. have led the public and private sectors to move towards sustainability i.e. using LCB for the production of biofuels and value-added compounds. A major bottleneck of the process is the recalcitrant nature of LCB. This can be overcome by using various pretreatment strategies like physical, chemical, biological, physicochemical, etc. Further, the pretreated biomass is made to undergo various steps like hydrolysis, saccharification, etc. for the conversion of value-added products and the remaining waste residues can be further utilized for the synthesis of secondary products thus favouring the zero-waste biorefinery concept. Currently, microorganisms are being explored for their use in biorefinery but the unavailability of commercial strains is a major limitation. Thus, the use of metagenomics can be used to overcome the limitation which is both cost-effective and environmentally friendly. The review deliberates the composition of LCBs, and their recalcitrance nature, followed by the structural changes caused by various pretreatment methods. The further steps in biorefineries, strategies for the development of zero-waste refineries, bottlenecks, and suggestions are also discussed. Special emphasis is given to the use of metagenomics for the discovery of microorganisms efficient for zero-waste biorefineries.

Influence of Carbon Sources on Biomass and Biomolecule Accumulation in Picochlorum sp. Cultured under the Mixotrophic Condition.

The major downfalls of the microalgal biorefinery are low volume of high value product accumulation, low biomass productivity and high cultivation costs. Here, we aimed to improve the biomass productivity of the industrially relevant Picochlorum sp. BDUG 100241 strain. The growth of Picochlorum sp. BDUG 100241 was investigated under different cultivations conditions, including photoautotrophic (with light), mixotrophic (1% glucose, with light) and heterotrophic (1% glucose, without light). Among them, Picochlorum sp. BDUG100241 showed the highest growth in the mixotrophic condition. Under different (1%) carbon sources' supplementation, including glucose, sodium acetate, glycerol, citric acid and methanol, Picochlorum sp. BDUG100241 growth was tested. Among them, sodium acetate was found to be most suitable carbon source for Picochlorum sp. BDUG 100241 growth, biomass (1.67 ± 0.18 g/L) and biomolecule productivity. From the different concentrations of sodium acetate (0, 2.5, 5.0, 7.5 and 10 g/L) tested, the maximum biomass production of 2.40 ± 0.20 g/L with the biomass productivity of 95 ± 5.00 mg/L/d was measured from 7.5 g/L in sodium acetate. The highest total lipid (53.50 ± 1.70%) and total carotenoids (0.75 ± 0.01 µg/mL) contents were observed at the concentration of 7.5 g/L and 5.0 g/L of sodium acetate as a carbon source, respectively. In conclusion, the mixotrophic growth condition containing 7.5 g/L of sodium acetate showed the maximum biomass yield and biomolecule accumulation compared to other organic carbon sources.

Extraction and characterization of microalgae-derived phenolics for pharmaceutical applications: A systematic review.

Microalgae are regarded as a rich trove of diverse secondary metabolites that exert remarkable biological activities. In particular, microalgae-derived bioactive phenolic compounds (MBPCs) are a boon to biopharmaceutical and nutraceutical industries due to their diverse bioactivities, including antimicrobial, anticancer, antiviral, and immunomodulatory activities. The state-of-the-art green technologies for extraction and purification of MBPCs, along with the modern progress in the identification and characterization of MBPCs, have accelerated the discovery of novel active pharmaceutical compounds. However, several factors regulate the production of these bioactive phenolic compounds in microalgae. Furthermore, some microalgae species produce toxic phenolic compounds that negatively impact the aquatic ecosystem, animal, and human life. Therefore, the focus of this review paper is to bring into light the current innovations in bioprospection, extraction, purification, and characterization of MBPCs. This review is also aimed at a better understanding of the physicochemical factors regulating the production of MBPCs at an industrial scale. Finally, the present review covers the recent advances in toxicological evaluation, diverse applications, and future prospects of MBPCs in biopharmaceutical industries.

Lichens as a repository of bioactive compounds: an open window for green therapy against diverse cancers.

Lichens, algae and fungi-based symbiotic associations, are sources of many important secondary metabolites, such as antibiotics, anti-inflammatory, antioxidants, and anticancer agents. Wide range of experiments based on in vivo and in vitro studies revealed that lichens are a rich treasure of anti-cancer compounds. Lichen extracts and isolated lichen compounds can interact with all biological entities currently identified to be responsible for tumor development. The critical ways to control the cancer development include induction of cell cycle arrests, blocking communication of growth factors, activation of anti-tumor immunity, inhibition of tumor-friendly inflammation, inhibition of tumor metastasis, and suppressing chromosome dysfunction. Also, lichen-based compounds induce the killing of cells by the process of apoptosis, autophagy, and necrosis, that inturn positively modulates metabolic networks of cells against uncontrolled cell division. Many lichen-based compounds have proven to possess potential anti-cancer activity against a wide range of cancer cells, either alone or in conjunction with other anti-cancer compounds. This review primarily emphasizes on an updated account of the repository of secondary metabolites reported in lichens. Besides, we discuss the anti-cancer potential and possible mechanism of the most frequently reported secondary metabolites derived from lichens.

Biosorption efficiency of nickel by various endophytic bacterial strains for removal of nickel from electroplating industry effluents: an operational study.

Realising the hazardous effect of nickel on human health, microbes and plants are effectively used for bioremediation. The endophytic microorganisms have an important role in the phytoremediation of nickel using Vigna radiata. Therefore, in order to harness the potential of microbial strains, the present study was designed to examine the metal biosorption ability of endophytic bacterial strains isolated from plants growing in nickel-contaminated soil. A total of six endophytic nickel resistance bacteria were isolated from the plant Vigna radiata. The metal tolerant bacterial strains were identified following 16 S rRNA gene sequence analysis. Nickel biosorption estimation and plant growth-promoting (PGP) activities of isolated strains were performed and found high nickel biosorption efficiency of 91.3 ± 0.72% at 600 mg L-1 using Bacillus safensis an isolated endophytic strain from Vigna radiata. Furthermore, high indole acetic acid (IAA) and exopolysaccharide (EPS) production were obtained in all the strains as compared to without nickel-containing medium used as control. Moreover, the production of high EPS suggests improved biosorption ability of isolated endophytic strains. In addition, a kinetic study was also performed to evaluate different adsorptions isotherms and support the nickel biosorption ability of endophytic strains. The treatment of nickel electroplating industrial effluent was also demonstrated by isolated endophytic strains. Among six (6) strains, B. cereus showed maximum 57.2 ± 0.62% biosorption efficiency of nickel which resulted in the removal of 1003.50 ± 0.90 mg L-1 of nickel from the electroplating industry effluents containing initial 1791 ± 0.90 mg L-1 of nickel. All other strains were also capable of significant nickel biosorption from electroplating industry effluents as well. Thus, isolated endophytic nickel tolerant strains can be further used at large-scale biosorption of nickel from electroplating industry effluent.

Phycoremediation of nitrogen and phosphate from wastewater using Picochlorum sp.: A tenable approach.

The wastewater originates from different industrial, municipal, and agriculture processes and contains different nitrogen sources, for example, nitrate, ammonium, nitrite, and phosphate such as inorganic and organic sources. The discharge of high nitrate and phosphate to the ecosystem or nearby water bodies can cause eutrophication which disbalances the aquatic ecosystem. Furthermore, ingestion of these pollutants can cause severe toxicity and disease to humans and animals. Thus, from an environmental and social perspective, its treatment is essential with no negative impact on the ecosystem. Microalgae are fundamental, mixotrophic microorganisms that treat different wastewater and utilize nitrate and phosphate in the medium as a source of nutrients. Among them, Picochlorum sp., have the potential to remove nitrogen and phosphate from wastewater. The biomass produced by Picochlorum sp. can be a promising candidate as a sustainable feedstock for biofuel and bioproducts formation. Thus, the present review provides a brief knowledge and understanding about the concentration of nitrogen and phosphate in different wastewater, their negative impacts, and the uptake mechanism of microalgae. Furthermore, the review also provides an insight into Picochlorum sp., and the effects of different physiological and nutritional factors on their growth, wastewater treatment efficacy, and biomass for value-added products and biorefinery applications. In addition, the review is useful to understand the potential of Picochlorum sp. for a tenable wastewater treatment process.

Current perspective on wastewater treatment using photobioreactor for Tetraselmis sp.: an emerging and foreseeable sustainable approach.

Urbanization is a revolutionary and necessary step for the development of nations. However, with development emanates its drawback i.e., generation of a huge amount of wastewater. The existence of diverse types of nutrient loads and toxic compounds in wastewater can reduce the pristine nature of the ecosystem and adversely affects human and animal health. The conventional treatment system reduces most of the chemical contaminants but their removal efficiency is low. Thus, microalgae-based biological wastewater treatment is a sustainable approach for the removal of nutrient loads from wastewater. Among various microalgae, Tetraselmis sp. is a robust strain that can remediate industrial, municipal, and animal-based wastewater and reduce significant amounts of nutrient loads and heavy metals. The produced biomass contains lipids, carbohydrates, and pigments. Among them, carbohydrates and lipids can be used as feedstock for the production of bioenergy products. Moreover, the usage of a photobioreactor (PBR) system improves biomass production and nutrient removal efficiency. Thus, the present review comprehensively discusses the latest studies on Tetraselmis sp. based wastewater treatment processes, focusing on the use of different bioreactor systems to improve pollutant removal efficiency. Moreover, the applications of Tetraselmis sp. biomass, advancement and research gap such as immobilized and co-cultivation have also been discussed. Furthermore, an insight into the harvesting of Tetraselmis biomass, effects of physiological, and nutritional parameters for their growth has also been provided. Thus, the present review will broaden the outlook and help to develop a sustainable and feasible approach for the restoration of the environment.