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Toxicity evaluation of environmental substances such as those in wastewater and contaminated water bodies has become an important part of environmental monitoring of pollution. The study evaluated the toxicity of estrogen hormones and the removal of toxicity in full-scale wastewater treatment plants (WWTPs) using the marine bacterium,Vibrio fischeri, and to determine if there is a correlation between the hormones and the toxicity in the effluents. Three different types of full-scale WWTPs were investigated and presence of estrogens in the treated wastewater was evaluated by enzyme linked immunoassay (ELISA). The toxicity of individual estrogens (E2, EE2, and a mixture of E1, E2, and E3) was investigated as well as influents and treated wastewater. The results revealed that all estrogen hormones had less than 50% inhibitions and fell in the Class II group that exhibits slight acute toxicity. The toxicity of the individual E2 hormone had higher inhibitions when compared to the individual synthetic EE2 and the mixture of the hormones. The toxicity results of the WWTP revealed that biological treatment can reduce the toxicity of the influent to an extent. The findings suggest that the residual estrogen contents as well as toxicity can be reduced in certain WWTPs. [ABSTRACT FROM AUTHOR]

The health hazard associated with the consumption of fish from the Gomti River in India, contaminated with the heavy metals Cr, Cu, Mn, Ni, Pb, and Zn was assessed in terms of target hazard quotients (THQs). The concentrations of metals (mg kg−1, wet weight basis) in the muscle tissues of different fish speciesMastacembelus puncalus, Clupisona garua, Cyrinous carpio, Botia lochachata, Channa punctatus, Heteropneustise fossilis, Puntius sofore,andClarious batrachusranged as follows: Cr (2.2–21.4), Cu (0.3–14.3), Mn (2.3–5.5), Ni (0.5–10.9), Pb (1.0–3.9), and Zn (12.3–46.9). The accumulation of metals in fish muscle tissue was in the order: Zn > Cr > Ni > Mn > Cu > Pb. THQs indicated a potential health hazard to children due to the consumption of fish contaminated with Ni and Pb; their THQs were greater than 1 for almost all fish species except for Ni inC. garua(THQ, 0.07) andC. carpio(THQ, 0.90). For adults, insignificant health hazard was associated with THQs less than 1 for all metals in the different fish species, but long-term exposure to these metals and subsequent bioaccumulation in the body may require additional investigation. [ABSTRACT FROM AUTHOR]

Anaerobic ammonium oxidation (ANAMMOX) is an efficient nitrogen removal process that is increasingly gaining traction within the wastewater treatment sector. However, slow growth rate of ANAMMOX bacteria (AMX) and their sensitivity to operating and environmental conditions hamper its widespread application. Although different control strategies have been developed, several challenges affecting process stability are still frequently reported and there is need for further improvements. This paper therefore critically reviews process control strategies applied in ANAMMOX-mediated systems, focusing on low- and high-strength treatment systems. The influence of different control strategies including those based on aeration regime, nitrogen (ammonium (NH 4 +), nitrite (NO 2 -) and nitrate (NO 3 -)) concentrations, ORP (oxidation-reduction potential), alkalinity, conductivity and pH on system performance was analysed and discussed. Factors such as NO 2 - inhibition, NO 3 - accumulation/reduction, SRT control, alkalinity depletion and maximisation of nitrogen removal were considered. In sum: (I) inclusion of supervisory layers in cascaded control structures enhance performance compared to regulatory structures that individually maintain parameter values within certain set limits, (II) Conductivity-, pH- and ORP-based controllers can prevent alkalinity depletion, (III) DEAMOX (DEnitrifying AMonium OXidation) requires less stringent conditions compared to partial nitrification-denitrification (PN/A), (IV) swing zones mitigate against limitation of active biomass population in mainstream systems, and (V) Regulatory pH- and DO-based strategies are prone to cause NO 2 --inhibition. [Display omitted] • Inclusion of supervisory controller enhances process performance. • SBRs controlled based on DO and pH are prone to nitrite inhibition. • ORP-, conductivity- and pH-based controllers prevent alkalinity depletion. • ORP controllers have slow response. [ABSTRACT FROM AUTHOR]

Mycosporine-like amino acids (MAAs) are ultraviolet-absorbing compounds synthesized by photoautotrophic microorganisms such as cyanobacteria. They have applications as UV protectants and antioxidants in the cosmetic and pharmaceutical sectors. To date, >30 different types of MAAs have been identified, having an absorption range between 310 and 365 nm that covers most of the UVR spectrum (~295–400 nm). In the study, MAAs were extracted and partially purified from a euryhaline Euhalothece sp. Thereafter, in silico analysis of the MAAs biosynthetic genes was conducted to determine the physicochemical characteristics, structural properties, functional analysis and homology model. High salinity stress (120 g L−1) significantly enhanced the production of MAAs (~56 %) in Euhalothece sp. Bioinformatics analysis of the genome of Euhalothece sp. revealed a distinctive mys gene cluster that contained six genes (mysA to mysE), compared to four genes commonly found in MAA-producing cyanobacteria. Interestingly, both EEVS and DHQ synthase were present, indicating the potential to synthesize MAAs via both the shikimate and sedoheptulose 7-phosphate pathways. Secondary structure analysis confirmed that in all the biosynthetic enzymes, the major components were the alpha-helices with random coils. This study emphasized the unique genes for MAAs in Euhalothece sp. as well as highlighted the potential metabolite pathways for commercial production. Elucidation of the protein structure, physicochemical properties, and interactions provides scientific insight into the biosynthesis of MAAs from hypersaline cyanobacteria. Additionally, it is essential for determining the applications of these novel photoprotective compounds. • A positive correlation between increased salinity and MAAs accumulation • The mys gene cluster of Euhalothece sp. contained six biosynthetic genes. • In silico characterization of MAAs protein structures were done. [ABSTRACT FROM AUTHOR]

The emergence and spread of antibiotic resistance through insufficiently treated effluents from wastewater treatment systems are detrimental to the receiving environment and human health. Metagenomic and transcriptomic approaches were employed to assess the diversity and the removal of bacterial pathogens, antibiotic-resistant genes (ARGs) and mobile genetic elements (MGEs) in three wastewater treatment plants (WWTPs) in Durban, South Africa. In total, 23 pathogenic bacterial genera, including enteric and emerging opportunistic pathogens, were found abundant in the samples. Aeromonas and Acinetobacter spp were the most dominant pathogens detected in the influent metagenomes, while the influent transcripts showed Escherichia and Acinetobacter spp as the most dominant pathogens. Shannon-Wiener indices showed that the bacterial diversity increased from influents to final effluents in two selected treatment plants. ARG types, including those conferring resistance to aminoglycosides, beta-lactamases, tetracycline and sulfonamide were abundant in both influent and effluent samples. Results further exposed that MGE-ARGs associations were the main drivers of ARG persistence into final effluents. This included 5 plasmids: R338-R151 (sulI), pRH-1238 (strB), pPM91 (aadA), pRH-1238 (aadA4–5), pRH-1238 (sulII); two class 1 integrons (aadA and arr) and 1 transposon Tn4351(tetX). In transcripts, MGE-ARG association showed two plasmids: pRH-1238 (aadA) and pPM91(aadA) and one hybrid plasmid R338-R151 (sulI). It was apparent across all the WWTPs that chlorination had little or no effect on MGE-ARG association. Combined, this study has highlighted the presence of bacterial pathogens, ARGs and MGEs in treated effluents, which can encourage the propagation of antibiotic resistance and potential sharing of genes in the downstream environments. [Display omitted] • Metagenomic and transcriptomic profiling of pathogens and antibiotic resistant genes and MGEs in wastewater in South Africa. • Aeromonas and Acinetobacter spp were the most dominant pathogens detected in the influent metagenomes. • Escherichia and Acinetobacter were the most abundant in the trsncripts. • Antibiotic resistant genes aaminoglycosides, beta-lactamases, tetracycline and sulfonamide were the most abundant. • Chlorination has little or no effect on MGE-ARG association was apparent across all WWTPs. [ABSTRACT FROM AUTHOR]

The worldwide prevalence of waterborne diseases has been attributed to the lack of safe water, inadequate sanitation and hygiene. This study evaluated socio-demographic factors, microbiological quality of water at source and point of use (POU) at households, water handling and sanitation practices in a rural Rwandan community. Thirty five water samples from the source, Nyabarongo River, and water at point of use (POU) treated with the Slow Sand Filter (SSF) and Sûr’Eau methods, were analysed for total coliform and faecal coliform counts. Turbidity was measured in household samples. A structured questionnaire regarding water collection, storage, usage and waterborne disease awareness was administered to 324 women. Despite the significant reduction in coliforms and faecal coliforms from the Nyabarongo River following treatment using either SSF or Sûr’Eau, the water at point of use was found to be unsafe for human consumption. The frequency of diarrheal diseases were significantly higher among people who did not wash hands before food preparation (P= 0.002) and after using a toilet (P= 0.007) than among those who did. There was a statistically significant association between education levels and water treatment practices at the households (P< 0.05). Participants had limited knowledge regarding water storage practices for prevention of household water contamination. A combination of treatment methods with appropriate water handling should be considered. In addition, education is a fundamental precursor to advocating water treatment at POU. [ABSTRACT FROM PUBLISHER]

Phenol, a common constituent in many industrial wastewaters is a major pollutant and has several adverse effects on the environment. The potential of various microorganisms to utilize phenol for their metabolic activity has been observed to be an effective means of remediating this toxic compound from the environment particularly wastewater. Five indigenous bacterial isolates (PD1-PD5) were obtained from phenol bearing industrial wastewater using the mineral salts medium. The isolates were further characterized based on their morphology, biochemical reactions and 16S rRNA phylogeny. The 16S rRNA sequence analysis using universal primers (27f/1492r) revealed that PD1, PD2, PD3and PD4were closely related to the actinomyceteRhodococcus pyrinidivorans(99%) and PD5toPseudomonas aeruginosa(99%). Growth kinetic patterns and phenol degradation abilities of the two representative isolates (PD1and PD5) were also evaluated. Both the species were effective in utilizing phenol as the sole carbon source and could tolerate phenol concentrations of up to 500 to 600 mg/L. The ability of these isolates to utilize higher concentrations of phenol as their sole carbon source makes them potential candidates and better competitors in the bioremediation process. [ABSTRACT FROM AUTHOR]

Anaerobic ammonium oxidation (ANAMMOX) represents an efficient, cost-effective, but sensitive nitrogen removal process for wastewater treatment. Different reactor configurations have been used in full-scale applications but each configuration has unique characteristics, which could influence process performance and community dynamics. The objective of this study is thus to analyze the impact of mixing conditions on nitrogen removal and community structures in a hybrid up-flow anaerobic sludge blanket reactor (H-UASB), moving bed biofilm reactor (MBBR) and gas-lift reactor (GLR). Community dynamics were studied through shotgun sequencing, while concentrations of NH 4 +, NO 3 - and NO 2 - were determined colorimetrically. During the study, MBBR displayed the highest average nitrogen removal efficiency (NRE) (67%) followed by H-UASB (63%), and then GLR (54%). The relative abundance of AMX in the suspended biomass was consistently higher in H-UASB than in MBBR and GLR, while that of nitrite-oxidizing bacteria (NOB) and complete ammonia-oxidizing bacteria (CMX) was higher in MBBR than in GLR and H-UASB. It was observed that the relative abundance of ammonia-oxidizing bacteria (AOB) in the suspended biomass fluctuated across the reactors. The relative abundance of CMX and Nitrospira in the biofilms in H-UASB and GLR was higher than in the suspended biomass, while comparable abundance was observed in MBBR. On the contrary, the relative abundance of AMX in the suspended biomass in H-UASB and MBBR was higher than in the biofilms, whereas it was comparable in the GLR. It was thus concluded that the mixing conditions in the three reactors influenced process performance and community dynamics. [Display omitted] • MBBR showed better nitrogen removal than H-UASB and GLR. • Growth of AMX was favored in suspended biomass in H-UASB and MBBR. • Growth of Nitrospira spp. and CMX was favored in biofilms in H-UASB and GLR. • Comparable growth of nitrifying bacteria in biofilms and suspended biomass in MBBR. • Comparable growth of AMX in biofilms and suspended biomass in GLR. [ABSTRACT FROM AUTHOR]

The rising concentration of global atmospheric carbon dioxide (CO2) has severely affected our planet's homeostasis. Efforts are being made worldwide to curb carbon dioxide emissions, but there is still no strategy or technology available to date that is widely accepted. Two basic strategies are employed for reducing CO2 emissions, viz. (i) a decrease in fossil fuel use, and increased use of renewable energy sources; and (ii) carbon sequestration by various biological, chemical, or physical methods. This review has explored microalgae's role in carbon sequestration, the physiological apparatus, with special emphasis on the carbon concentration mechanism (CCM). A CCM is a specialized mechanism of microalgae. In this process, a sub-cellular organelle known as pyrenoid, containing a high concentration of Ribulose-1,5-bisphosphate carboxylase-oxygenase (Rubisco), helps in the fixation of CO2. One type of carbon concentration mechanism in Chlamydomonas reinhardtii and the association of pyrenoid tubules with thylakoids membrane is represented through a typical graphical model. Various environmental factors influencing carbon sequestration in microalgae and associated techno-economic challenges are analyzed critically. [ABSTRACT FROM AUTHOR]

WASTEWATER TREATMENT FACILITIES are largely accountable for the detrimental enrichment of water bodies with nitrogenous compounds, resulting in eutrophication. Denitrification is of interest as a means of removing nitrates and nitrites from water supplies because they are also hazardous to human health. The integration of biological nutrient removalinto conventional wastewater treatment processes has, however, failed to take into sufficient consideration the role of key microorganisms present, specifically denitrifying bacteria. The purpose of the study reported here was to group such heterotrophic denitrifying bacteria using a series of biochemical and molecular analyses, to achieve an improved understanding of their functions. The role of the denitrifying bacteria in reducing nitrate and nitrite was monitored using the colorimetric nitrate reduction test. The genetic diversity of the culture collection was investigated by the use of denaturing gradient gel electrophoresis (DGGE), which enabled the creation of a microbial population profile of eight predominant isolates. Batch experiments were conducted on these isolates, the results of which ultimately confirmed their classification according to their respective functions, namely, incomplete denitrifiers, true denitrifiers, sequential denitrifiers, and exclusive nitrite reducers. [ABSTRACT FROM AUTHOR]

Increasing amounts of wastewater is the most pervasive and challenging environmental problem globally. Conventional treatment methods are costly and entail huge energy, carbon consumption and greenhouse gas emissions. Owing to their unique ability of carbon capturing and resource recovery, microalgae-microbiome based treatment is a potential approach and is widely used for carbon-neutral wastewater treatment. Microalgae-bacteria synergy (i.e., the functionally beneficial microbial synthetic communities) performs better and enhances carbon-sequestration and nutrient recovery from wastewater treatment plants. This review presents a comprehensive information regarding the potential of microalgae-microbiome as a sustainable agent for wastewater and discusses synergistic approaches for effective nutrient removal. Moreover, this review discusses, the role of omics-biology and Insilco approaches in unravelling and understanding the algae-microbe synergism and their response toward wastewater treatment. Finally, it discusses various microbiome engineering approaches for developing the effective microalgae-bacteria partners for carbon sequestration and nutrient recovery from wastewater, and summarizes future research perspectives on microalgae-microbiome based bioremediation. [ABSTRACT FROM AUTHOR]

This study proposed a two-step process optimization for enhanced cumulative isoprene production. This involves establishing an isoprene biosynthetic pathway in Escherichia coli BL21 DE-3 via up-regulation of native deoxy xylulose 5-phosphate (DXP) synthase (Ec DXS), isopentenyl pyrophosphate isomerase (Ec IPPI /Ec IDI) and introducing isoprene synthase (Pm IspS) from kudzu (Pueraria montana), followed by the process conditions (incubation temperature, time, and inducer concentration) optimization using the Box-Behnken design (BBD) approach. BBD showed the maximum cumulative isoprene production (160.15 mg L-1), productivity (11.18 mg L-1 h-1), and yield (7.69 mg gdcw-1) at the optimized process conditions (incubation temperature 27.32 ºC, incubation time 14.25 h, and inducer concentration 0.453 mM). The transgenic E. coli isoprene production, -productivity, and -yield were 1.52-, 1.46-, and 1.24-fold higher than the unoptimized condition (incubation temperature 30 ºC, incubation time 16 h, and inducer concentration 0.10 mM). This work demonstrates that fine tuning of MEP pathway in addition with process conditions optimization is an efficient strategy for improving isoprene production from engineered E. coli. [Display omitted] • Isoprene, a high-value natural product, entirely being produced by petroleum route. • Recombinant E. coli has potential for sustainable production of isoprene. • DXS, IPPI, and IspS were overexpressed under IPTG inducible promoter. • RSM based statistical model was used for optimizing culture growth conditions. • Engineered E. coli produced 160.15 mg L-1 of isoprene at optimal values of variables. [ABSTRACT FROM AUTHOR]

• Heterogeneous catalyst β-strontium silicate has been used for the first time for biodiesel production. • Catalyst have been performed up to six cycles with 76.34% FAME conversion. • Transesterification process was optimized by response surface methodology (RSM). • A FAME conversion of 97.88% was obtained from spirulina sp. microalgal oil. The β-Strontium silicate (β -Sr 2 SiO 4) was synthesized by physicochemical methods and was used as a heterogeneous catalyst in biodiesel production from microalgal oil (- S pirulina platensis ) by transesterification process. The physical and chemical properties of the catalyst were analysed using TGA, XRD, ATR-FTIR, SEM-EDX, and surface area analyser. XRD and FTIR analyses confirmed the formation of β-Sr 2 SiO 4 which was able to perform transeterification reaction. Several reaction parameter such as catalyst wt %, molar ratio (methanol :oil) and time have been optimized for transesterification reaction. The optimization of reaction parameters was accomplished by response surface methodology based on Box-Behnken design. Reusability study of catalyst was accomplished up to six run with 76.34% fatty acid methyl ester (FAME) conversion. A 97.88% maximum FAME conversion was observed at 65 °C, 600 rpm, 2.5 wt% catalyst, 1:12 methanol to oil molar ratio and 104 min reaction time. The biodiesel properties conform to ASTM standards. [ABSTRACT FROM AUTHOR]

The quality of surface water could be influenced by both anthropogenic and natural factors. This study was designed to determine the impact of informal settlement and wastewater treatment plants on helminth egg contamination of urban rivers and the risks associated with everyday use. We also ascertained the accumulation of these eggs in the river sediments. The study was carried out in two rivers in the eThekwini Municipality of South Africa. Grab samples were taken at different points over a 10-month period. Ascaris spp., hookworm, Toxocara spp., Trichuris spp. and Taenia spp. were the helminth eggs detected in both the water column and sediments, with mean Ascaris spp. eggs of 0–6.3 (± 5.1)/L in the water and 0–6.8 (± 5.2)/kg in sediment samples. The helminth egg concentrations showed seasonal variation, probably due to changes in infection levels of the populations or natural factors, such as rainfall. The informal settlements had a greater impact than treated wastewater. For every 10,000 recreational users of the rivers 19 to 58 may be infected under undisturbed conditions, increasing to 29–88 individuals when the riverbed is disturbed. The risk from agricultural use of the rivers was above the tolerable risk values applicable for wastewater reuse, recommended by the World Health Organization. This calls for a re-evaluation of the policies governing surface water quality assessment, where the inclusion of helminth eggs and sediment monitoring will be critical. [ABSTRACT FROM AUTHOR]

C-Phycocyanin is a water-soluble, light-harvesting accessory pigment known to possess excellent biotechnological applications due to its intense color, fluorescent properties and health benefits. In this study, the physicochemical properties and protein structure of C-Phycocyanin from a halophile Euhalothece sp. were predicted based on the in silico analysis of the amino acid sequences. The effect of temperature and pH on the yield, as well as stability and antioxidant activity of purified C-Phycocyanin was determined. Based on the in silico analysis, the α -subunit is composed of 162 amino acids (17.76 kDa) covalently linked to the phycocyanobilin at the Cys84 position, and the β -chain contains 172 amino acids (18.48 kDa) attached to two phycocyanobilins at Cys82 and Cys153 positions. The physicochemical properties revealed that these proteins are non-polar and stable. Multiple sequence alignment analyses of the subunits displayed significant differences amongst the amino acids of hypersaline/marine and freshwater cyanobacteria. These amino acids play a vital role in the stability of the C-Phycocyanin. The secondary structure prediction of the α - and β -subunits consisted of >50% of amino acid residues in α -helices, with 9–13% of amino acid residues in the extended strand. To further verify the results, C-Phycocyanin was found thermostable up to 45 °C with an optimum pH range between 5.0 and 7.0. The yield and thermostability of C-Phycocyanin were observed to be pH-dependent, where a lower pH (<6.0) improved the stability at higher temperatures (>50 °C) and vice - versa. Based on the in vitro assays, C-Phycocyanin had a high antioxidant activity i. e. 90.0 ± 0.045% scavenging activity at 0.08 mg mL−1 and reducing power efficiency of 85.15 ± 0.012% at 150 μg mL−1. The higher antioxidant activity levels of the C-Phycocyanin could be a result of the presence of high level of non-polar and aromatic amino acids (Ala, Gly Glu, Leu, Arg, Ser, and Val). Unlabelled Image • In silico amino acid analysis and physicochemical properties of C-Phycocyanin subunits and linker proteins. • Thermostability of purified C-Phycocyanin was pH-dependent. • Amino acids positively contributed to C-Phycocyanin high antioxidant activity. [ABSTRACT FROM AUTHOR]

Presents a study which designed and operated a laboratory-scale biological treatment process that would produce effluent with a low chemical oxygen demand and phosphate content prior to discharge to the municipal sewer system. Materials and methods; Characteristics of edible oil refining effluent during sampling; Results and discussion.

The availability of light and its efficient utilisation is a major limiting factor in large scale algal cultures. While algae predominantly use the blue and red spectral regions, a significant amount of incoming light energy remains untapped outside these ranges. Converting this unused light into usable wavelengths could enhance photosynthesis. This study aimed to identify the optimal spectral converter among Lumogen Red (LR), Rhodamine 8G (R8G), and Lumogen Yellow (LY), providing efficient light utilisation for algal cultivation. Chlamydomonas reinhardtii was cultivated in double-jacketed cylindrical photo-bioreactors (PBRs) using 30% UV-a and 5% UV-b fluorescent tubes. The R8G dye displayed a slight wavelength shift with a sharp peak at about 498 nm. The LY dye demonstrated several sharp peaks at the green and blue light spectra evident of photo-degradation. The LR dye maintained better photo-stability compared to R8G and LY. Carbohydrate, lipid and protein were produced early, whereas biomass increased after day 4, as a result of photo-acclimation. The LR dye converted and emitted 3.17 × 10-19 J photon-1, enhancing biomass production and increasing photochemical energy utilisation [Y(II)] while decreasing regulated energy dissipation [Y(NPQ)]. Pigment biosynthesis was initially increased and then reduced to counteract heightened irradiation as a means of photo-protection. LR had a 1.6- and 2.9-fold up-regulation of the RuBisCo gene expression. The dye-based system correlated with improved growth, lipid, protein, carbohydrate, and pigment production. The dye-based wavelength conversion system was interlinked to the sustainable development goals addressing environmental, economic, and social aspects. [ABSTRACT FROM AUTHOR]

The multibillion-dollar carbonated beverage industry is currently facing questions from health-conscious consumers over negative health effects of such beverages. Decreasing consumption trends have forced companies to look for healthier choices for their products. C-phycocyanin CPC, a bright blue cyanobacterial pigment with anti-oxidant and other health benefits has been proposed as a candidate in edible drinks. We found that CPC is stable in a wide pH and temperature regime. Reaction kinetics for 12 weeks at 4 °C in non-alcoholic carbonated beverages (B1-B4) showed that B3 (sweetened, ~30 % degradation) best preserved CPC integrity while B1 (non-sweetened, ~87 % degradation) was ineffective. Other beverages (sweetened) could preserve ~ 49 % CPC integrity. Behnajady-Modirshahla-Ghanbary and first order kinetic models explained CPC degradation with and without preservative (sucrose), respectively. The 'consume-by' times suggest possible refrigeration from ~ 13 hours to 27 days for various CPC-containing beverages. Results suggest CPC could be filter-sterilized and added to non-alcoholic beverages before being packaged in cans or tetra packs to avoid light exposure. [ABSTRACT FROM AUTHOR]

Pyrolysis of nutrient-stressed Scenedesmus obliquus microalgae over various supported metal M/Fe3O4-HZSM-5 catalysts (M = Zr, W, Co and Mo) was investigated at a temperature of 500 °C and catalyst to biomass ratio of 1:1. The synthesized catalysts were characterized using XRD, TGA and HRSEM/EDS. The influence of temperature (400 °C, 500 °C, 600 °C and 700 °C) and catalyst to biomass ratio (0.25:1, 0.5:1 and 1:1) on pyrolysis product yield was also investigated. The results showed that all the supported metal catalysts during pyrolysis promote aromatization and acid ketonization of bio-oils. The total amounts of acids present in pyrolytic bio-oil significantly decreased from 26.68% (non-catalytic) to between 0.58 and 9.68% (catalytic). Also, production of 2-pentanone was observed to increase from ∼10% (non-catalytic) to 27.36–53.90% (catalytic). In terms of energy recovery, Co/Fe3O4-HZSM-5 had about 40% energy recovery, which was the highest while the least performing catalyst was W/Fe3O4-HZSM-5 with 24.18% energy recovery in bio-oil. Overall, Co/Fe3O4-HZSM-5 catalyst showed better activity in enhancing the bio-oil quality and yield; it had the lowest nitrogen content (4.77 wt%) and highest bio-oil yield (17.73 wt %) as well as highest HHV (39.12 MJ/kg) which is almost similar to that of crude petroleum. • Use of catalysts on nutrient stressed microalgae to enhance bio-oil quality studied. •Co/Fe3O4-HZSM-5 showed better activity in enhancing bio-oil quality and yield. •Deoxygenation, denitrogenation, aromatization and acid ketonization was promoted. •Pyrolysis bio-oil with properties close to that of petroleum crude was obtained. •HHV was improved from 36.99 MJ/kg (noncatalytic) to 38.20–39.12 MJ/kg (catalytic). [ABSTRACT FROM AUTHOR]

Sulfide-based pathways for generating nitrite to sustain anaerobic ammonium oxidation (anammox) have garnered increasing attention. However, the presence of sulfide can also impact the anammox process, necessitating a comprehensive understanding of both its short-term and long-term effects on anammox. This study aimed to investigate the influence of sulfide on anammox, including its effects on the microbial community and process kinetics. During long-term operation, the maximum sulfide dosage tested was 30 mg S/L over 50 days of operation, exhibiting good nitrogen removal efficiency of 83.9%±4.8%. Conversely, under short-term exposure to sulfide, nitrogen removal efficiency was notably affected, decreasing to 68.98% at a considerably lower sulfide concentration of only 16 mg S/L. Within the context of long-term sulfide exposure, the maximum contribution of anammox to nitrogen removal reached 86.72% at a sulfide dosage of 25 mg S/L. However, when the influent sulfide concentration was increased to 50 mg/L , the contribution of anammox to nitrogen removal sharply declined to 41.3%. Microbial community analysis revealed as the sulfide concentration increased from 8 to 16 mg S/L , the abundance of anammox bacteria decreased from 2.46×105 to 1.67×105 copies/mL, whereas the abundance of Nitrobacter spp. increased from 2.73×102 to 8.13×102 copies/mL. However, during long-term operation, there was a more pronounced decrease in the microbial abundance of anammox, reducing from 5.3×105 to 3.77×102 copies/mL. Taking this decrease together with the improved efficiency of anammox observed during long-term operation, these findings suggest that sulfide's influence on anammox primarily impacts its metabolic activity rather than its microbial abundance. [ABSTRACT FROM AUTHOR]

Machine learning (ML) models are widely used methods for analyzing data from sensors and satellites to monitor climate change, predict natural disasters, and protect wildlife. However, the application of these technologies for monitoring and managing algal blooms in freshwater environments is relatively new and novel. The commonly used models in algal blooms (ABS) so far are artificial neural networks (ANN), random forests (RF), support vector machine (SVM), data-driven modeling, and long short-term memory (LSTM). In the past, researchers have mostly worked on predicting the effluent parameters, nutrients, microculture, area and weather conditions, meteorological factors, ground waters, energy optimization, and metallic substances in algal blooms using ML models. Most of the studies have employed performance metrics like root mean squared error, mean squared error, peak signal, precision, and determination coefficient as their primary model performance measures for accuracy analysis, and the usage of transfer, and activation function. While there have been some studies on this topic, several research gaps are still to be addressed. The most significant gaps are related to the limited application of ML in different algae bloom scenarios, the interpretability of ML models, and the lack of integration with existing monitoring systems. Keeping these in mind, this review article has been methodically arranged to present an overview of the past studies, their limitations, and the way forward toward the application of ML in the prediction of ABS, thus benefitting future researchers in this area. This review aims to summarize the data that are available, including some benchmarking values. Real-time monitoring of dynamics using ML is essential for mitigating algal blooms. Various complexities hinder applications of current ML algorithms in ABS. Activation and transfer functions can be used for selection of ML to predict ABS. Integrated ML algorithms can drive feature engineering to predict and control ABS. [ABSTRACT FROM AUTHOR]

Terpenoids and their derivatives which are synthesized either through the methylerythritol phosphate (MEP) or mevalonate (MVA) pathways represent a most diversified class of natural compounds with a wide range of therapeutic properties such as anticancer, antimicrobial, antiparasitic, and antiallergenic. Globally, terpenoids are in high demand due to their excellent pharmaceutical applications and their potential benefits in many sectors. Since tiny quantities of these compounds are present in nature, their large-scale uses are limited. Moreover, the petroleum-based production of these compounds is managing the current market demand worldwide. Nevertheless, the increase in greenhouse gas emissions and global warming makes the above approach unsustainable for commercial scale production. This can be addressed by metabolic pathway engineering, a promising method of synthetic biology that enables the efficient modification of microbial pathways to produce high value compounds on a continuous and sustainable basis. In this review, we primarily focused on the importance and utility of the MEP pathway toward the biosynthesis of specific terpenoids. In addition, different types of terpenoids, their industrial values, and engineering initiatives to increase the titers of valuable terpenoids from promising cell factories are also discussed. [Display omitted] • Terpenoids are high value natural compounds, their use at industrial scale suffers from its low productivity. • MEP pathway is superior to MVA in terms of carbon utilization, oxygen consumption, and theoretical yields, but less explored. • More research for successful expression of MEP pathway in MVA pathway expressing hosts need to be carried out in future. • Challenges and strategies for sustainable production, with promising technologies toward titers improvement, is presented. [ABSTRACT FROM AUTHOR]

An integrated approach to nutrient recycling utilizing microalgae could provide feasible solutions for both environmental control and energy production. In this study, an axenic microalgae strain, Chlorella sorokiniana ASK25 was evaluated for its potential as a biofuel feedstock and textile wastewater (TWW) treatment. The microalgae isolate was grown on TWW supplemented with different proportions of standard BG-11 medium varying from 0 to 100% (v/v). The results showed that TWW supplemented with 20% (v/v) BG11 medium demonstrated promising results in terms of Chlorella sorokiniana ASK25 biomass (3.80 g L−1), lipid production (1.24 g L−1), nutrients (N/P, > 99%) and pollutant removal (chemical oxygen demand (COD), 99.05%). The COD level dropped by 90% after 4 days of cultivation, from 2,593.33 mg L−1 to 215 mg L−1; however, after day 6, the nitrogen (-NO3−1) and total phosphorus (TP) levels were reduced by more than 95%. The biomass-, total lipid- and carbohydrate- production, after 6 days of cultivation were 3.80 g L−1, 1.24 g L−1, and 1.09 g L−1, respectively, which were 2.15-, 2.95- and 3.30-fold higher than Chlorella sorokiniana ASK25 grown in standard BG-11 medium (control). In addition, as per the theoretical mass balances, 1 tonne biomass of Chlorella sorokiniana ASK25 might yield 294.5 kg of biodiesel and 135.7 kg of bioethanol. Palmitic acid, stearic acid, and oleic acid were the dominant fatty acids found in the Chlorella sorokiniana ASK25 lipid. This study illustrates the potential use of TWW as a microalgae feedstock with reduced nutrient supplementation (20% of TWW). Thus, it can be considered a promising feedstock for economical biofuel production. [ABSTRACT FROM AUTHOR]

The objective of the study was to assess the physico-chemical composition and process variations of the effluent from a brewery industry located in KwaZulu - Natal, South Africa during the months of September 2011 to May 2012. The parameters monitored for the quantitative analysis of brewery wastewater include the total and soluble chemical oxygen demand (TCOD and SCOD), biological oxygen demand (BOD5), total solids (TS), volatile solids (VS), total suspended solids (TSS), volatile suspended solids (TSS), pH, ammonia (NH3), total oxidized nitrogen, nitrate, nitrite, phosphorus, electrical conductivity (EC), crude protein and alkalinity content. On the average, the TCOD and SCOD concentrations of the brewery effluent were 5340.97 and 3902.24 mg/L, respectively, with average pH values of 4.0 to 6.7. The BOD and the solids content of the effluent from the brewery industry were high indicating that the effluent is of biodegradable type. This suggests that the effluent is very rich in organics, and its discharge into the water bodies or the municipal treatment plant can cause environmental pollution or damage the treatment plant. In addition, there were variations in the effluent composition throughout the period of monitoring which might be due to the activities that take place during the production process and the effects of peak periods of beer production. Thus, there is a need for an on-site effluent treatment plant in order to reduce the high pollution of the effluent prior to its discharge to the municipal wastewater treatment plants. [ABSTRACT FROM AUTHOR]

This document is a correction notice for an article titled "Axenic green microalgae for the treatment of textile effluent and the production of biofuel: a promising sustainable approach" published in the World Journal of Microbiology & Biotechnology. The correction pertains to the composition of fatty acid methyl esters in the oil produced by Chlorella sorokiniana ASK25. The corrected composition includes various fatty acids such as C14:0, C16:0, C16:1, C18:0, C18:1, C18:3, C19:0, and others. Saturated fatty acids (SFA) accounted for 48.84% of the composition, followed by unsaturated fatty acids (USFA) at 40.95%. The correction was made by Ashutosh Pandey, Gaurav Kant, Ashwani Chaudhary, Kassian T. T. Amesho, Karen Reddy, and Faizal Bux. [Extracted from the article]

The degradation of persistent and refractory pollutants, particularly plastic and resins manufacturing wastewater, poses a significant challenge due to their high toxicity and high concentrations. This study developed a novel hybrid ACoO 3 (A = La, Ce, Sr)/PMS perovskite system for the treatment of multicomponent (MCs; ACN, ACM and ACY) from synthetic resin manufacturing wastewater. Synthesized perovskites were characterized by various techniques i.e., BET, XRD, FESEM with EDAX, FTIR, TEM, XPS, EIS, and Tafel analysis. Perovskite LaCoO 3 exhibited the highest degradation of MCs i.e., ACN (98.7%), ACM (86.3%), and ACY (56.4%), with consumption of PMS (95.2%) under the optimal operating conditions (LaCoO 3 dose 0.8 g/L, PMS dose 2 g/L, pH 7.2 and reaction temperature 55 °C). The quantitative contribution (%) of reactive oxygen species (ROS) reveals that SO 4 •− are the dominating radical species, which contribute to ACN (58.3% for SO 4 •− radicals) and ACM degradation (46.4% for SO 4 •− radicals). The tafel plots and EIS spectra demonstrated that perovskites LaCoO 3 have better charge transfer rates and more reactive sites that are favorable for PMS activation. Further, four major degradation pathways were proposed based on Fukui index calculations, as well as GC-MS characterization of intermediate byproducts. Based on a stability and reusability study, it was concluded that LaCoO 3 perovskites are highly stable, and minimal cobalt leaching occurs (0.96 mg/L) after four cycles. The eco-toxicity assessment performed using QSAR model indicated that the byproducts of the LaCoO 3 /PMS system are non-toxic nature to common organism (i.e., fish, daphnids and green algae). In addition, the cost of the hybrid LaCoO 3 /PMS system in a single cycle was estimated to be $34.79 per cubic meter of resin wastewater. [Display omitted] • LaCoO 3 /PMS system shows excellent performance for synthetic resin wastewater. • Four potential degradation routes of MCs were proposed based on DFT analysis. • QSAR model predict the toxicity of synthetic resin wastewater and their by-products. • LaCoO 3 /PMS system provided low treatment cost 34.79$/m3 of resin wastewater. • Perovskite LaCoO 3 exhibited excellent stable material with 0.96 mg/L cobalt leaching. [ABSTRACT FROM AUTHOR]

Improper lignocellulosic wastes management causes severe environmental pollution and health damage. Conversion of such wastes particularly sugarcane bagasse (SCB) onto bioenergy is a sustainable approach due to a continuous depletion of conventional biofuels. The delignification of SCB is necessary to proceed for bio-genic H 2 productivity by anaerobic bacteria. The effect of autoclaving, pre-acidification/autoclaving and pre-alkalization/autoclaving of SCB on glucose recovery and subsequently H 2 productivity by dark fermentation was comprehensively investigated. Pre-acidified SCB with 1% H 2 SO 4 (v/v) provided H 2 productivity of 8.5 ± 0.14 L/kg SCB and maximum H 2 production rate (R m) of 105.9 ± 8.3 mL/h. Those values were dropped to 2.7 ± 0.13 L/kg SCB and 58.3 ± 12.9 mL/h for fermentation of delignified SCB with 2% H 2 SO 4. This was linked to high levels of total phenolic compounds (1775.3 ± 212 mg/L) in the feedstock. Better H 2 productivity of 13.9 ± 0.58 L/kg SCB and R m of 133.9 ± 3.6 mL/h was achieved from fermentation of pre-alkalized SCB with 1%KOH (v/v). 256.8 ± 9.8 U/100 mL of α-amylase, 165.7 ± 7.6 U/100 mL of xylanase, 232.8 ± 6.1 U/100 mL of CM-Cellulase, 176.5 ± 5.0 U/100 mL of polyglacturanase and 0.702 ± 0.013 mg M B. reduced/min. of hydrogenase enzyme was accounted for the batches supplied with delignified SCB by KOH. The Clostridium and Bacillus spp. was dominance and prevalence resulting a higher H 2 productivity and yield. A novel strain of Archea and alpha proteobacterium were also identified and detected. [Display omitted] • Sugarcane bagasse (SCB) is low cost substrate for effectively H 2 productivity. • Fermentation of pre-acidified SCB provided H 2 productivity of 8.5 ± 0.14 L/kg SCB. • 13.9 ± 0.58 LH 2 /kg SCB was obtained from fermentation of pre-alkaline SCB. • A significant reduction of phenolic compounds was obtained in alkaline SCB. • Bacillus subtilis and Clostridium amylolyticum strains were dominant H 2 species. [ABSTRACT FROM AUTHOR]

The Hydrothermal liquefaction (HTL) of a nutrient-stressed microalgae (Scenedesmus obliquus) (NSM) with and without the use of zirconium-doped HZSM-5 catalyst was investigated under temperature conditions ranging from 250 to 350 °C. The wet impregnation method was used to prepare the catalyst, and HTL experiments were conducted on the unstressed microalgae (CM) for comparison. Under the stressed condition, the protein content of the microalgae was reduced from 42.35% to 22.08% while the carbohydrate and lipid contents were increased from 25.36% to 42.55% and 17.16%–21.62% respectively. The maximum HTL bio-oil yield of 52.8 wt% and 24.27 wt% were found for NSM and CM respectively at 350 °C with addition of Zr-HZSM-5 catalyst. Higher denitrogenation and deoxygenation was achieved with NSM compared to CM. At high temperature of 350 °C, the most abundant fatty acid in NSM was found to be cis -vaccenic acid (omega-7- fatty acid), and this could be explored for the possibility of extracting products of great value from the bio-oil for applications other than biofuels. Mainly, the use of Zr-doped HZSM-5 catalyst on nutrient-stressed S. obliquus microalgae resulted in enhanced bio-oil yield and characteristics which compared well with petroleum crude. • Nutrient stressing altered the microalgae compositions especially reduction of protein by ∼50%. • The presence of Zr/HZSM-5 catalyst was beneficial and improved the HTL bio-oil yield and quality. • The nitrogen content in HTL bio-oil from stressed algae was within the range for petroleum crude and the most abundant fatty acid was found to be omega-7 fatty acid. • High heating value (43.56 MJ kg−1) within the range for petroleum crude (42–48 MJ kg−1) was achieved. • Suitability of nutrient stressed algae in enhancing the quality of HTL bio-oil was established. [ABSTRACT FROM AUTHOR]

[Display omitted] • Synthetic NPs are extensively focused on various aspects of algal systems. • Due to unsustainability concerns, transitioning to eco-friendly NPs is rising. • Yet, very few researchers work on 'green' and natural NPs for algal enhancement. • Natural/'Green' NPs are being used for algal harvesting, with few for cultivation. • Growing market stresses future research on more sustainable NPs for algae systems. Algae cultivation and bioprocessing are important due to algae's potential to effectively tackle crucial environmental challenges like climate change, soil and water pollution, energy security, and food scarcity. To realize these benefits high algal biomass production and valuable compound extraction are necessary. Nanotechnology can significantly improve algal cultivation through enhanced nutrient uptake, catalysis, CO 2 utilization, real-time monitoring, cost-effective harvesting, etc. Synthetic nanoparticles are extensively used due to ease of manufacturing and targeted application. Nonetheless, there is a growing interest in transitioning to environmentally friendly options like natural and 'green' nanoparticles which are produced from renewable/biological sources by using eco-friendly solvents. Presently, natural, and 'green' nanoparticles are predominantly utilized in algal harvesting, with limited application in other areas, the reasons for which remain unclear. This review aims to critically evaluate research on nanotechnology-based algae system enhancement, identify research gaps and propose solutions using natural and 'green' nanoparticles for a sustainable future. [ABSTRACT FROM AUTHOR]

This study focuses on the removal and risk assessment of twenty emerging contaminants (ECs) and heavy metals in a REMIX water treatment plant (RWTP) that produces drinking water from combination of wastewater reuse and desalination. The membrane biological reactor (MBR) exhibit removal rates exceeding 95% of pharmaceuticals like acetaminophen, trimethoprim, diclofenac, naproxen, and emtricitabine. The efficiency of brackish reverse osmosis (BWRO) in removing ECs is highlighted, showing substantial efficacy with reduction rates of 99.5%, 75.5%, and 51.2% for sulfamethoxazole, venlafaxine, and benzotriazole, respectively. The advanced oxidation process based on Fenton process reveals removal (>95%) of emtricitabine, efavirenz, and carbamazepine. The study confirms that the combination of treatment units within the RWTP effectively removes heavy metals (>90%), complying with acceptable limits. Risk quotient (RQ) calculations indicate the efficiency of the RWTP in EC removal, serving as benchmarks for public acceptance of reclaimed water. In the context of heavy metals, the study concludes negligible cancer risks associated with reclaimed water consumption over a lifetime. Quantitative structure-activity relationship and occurrence, persistence, bioaccumulation and toxicity (OPBT) models were used to assess EC risk. The study screened and identified potential persistant, bio accumulating and toxic PBT ECs. Critical control points (CCPs) in the RWTP are identified, with brackish and seawater reverse osmosis (BWRO and SWRO) and advanced oxidation process (AOP) recognized as pivotal in hazard management. The study provides valuable insights on the removal of ECs and heavy metals in a wastewater reuse process and demonstrates potential of adopted process configuration in supplying safe drinking water from wastewater recycling. [Display omitted] • A novel process combining wastewater reuse and desalination studied for EC removal. • OPBT based risk assessment carried out for EC occurrence in recycled water. • Heavy metals in recycled water were within limits, removal >90% and HQ < 1. • Critical control points (CCPs) in the process for EC removal were identified. [ABSTRACT FROM AUTHOR]

Phosphorus in wastewater poses a significant environmental threat, leading to water pollution and eutrophication. However, it plays a crucial role in the water-energy-resource recovery-environment (WERE) nexus. Recovering Phosphorus from wastewater can close the phosphorus loop, supporting circular economy principles by reusing it as fertilizer or in industrial applications. Despite the recognized importance of phosphorus recovery, there is a lack of analysis of the cyber-physical framework concerning the WERE nexus. Advanced methods like automatic control, optimal process technologies, artificial intelligence (AI), and life cycle assessment (LCA) have emerged to enhance wastewater treatment plants (WWTPs) operations focusing on improving effluent quality, energy efficiency, resource recovery, and reducing greenhouse gas (GHG) emissions. Providing insights into implementing modeling and simulation platforms, control, and optimization systems for Phosphorus recovery in WERE (P-WERE) in WWTPs is extremely important in WWTPs. This review highlights the valuable applications of AI algorithms, such as machine learning, deep learning, and explainable AI, for predicting phosphorus (P) dynamics in WWTPs. It emphasizes the importance of using AI to analyze microbial communities and optimize WWTPs for different various objectives. Additionally, it discusses the benefits of integrating mechanistic and data-driven models into plant-wide frameworks, which can enhance GHG simulation and enable simultaneous nitrogen (N) and Phosphorus (P) removal. The review underscores the significance of prioritizing recovery actions to redirect Phosphorus from effluent to reusable products for future considerations. [Display omitted] [ABSTRACT FROM AUTHOR]