Microplastic contamination in wastewater: Sources, distribution, detection and remediation through physical and chemical-biological methods.

Microplastics are tiny plastic particles smaller than 5 mm. that have been widely detected in the environment, including in wastewater. They originate from various sources including breakdown of larger plastic debris, release of plastic fibres from textiles, and microbeads commonly used in personal care products. In wastewater, microplastics can pass through the treatment process and enter the environment, causing harm to biodiversity by potentially entering the food chain. Additionally, microplastics can act as a vector for harmful pollutants, increasing their transport and distribution in the environment. To address this issue, there is a growing need for effective wastewater treatment methods that can effectively remove microplastics. Currently, several physical and chemical methods are available, including filtration, sedimentation, and chemical degradation. However, these methods are costly, low efficiency and generate secondary pollutants. Furthermore, lack of standardization in the measurement and reporting of microplastics in wastewater, makes it difficult to accurately assess microplastic impact on the environment. In order to effectively manage these issues, further research and development of effective and efficient methods for removing microplastics from wastewater, as well as standardization in measurement and reporting, are necessary to effectively manage these detrimental contaminants.

EnCPdock: a web-interface for direct conjoint comparative analyses of complementarity and binding energetics in inter-protein associations.

CONTEXT: Protein-protein interaction (PPI) is a key component linked to virtually all cellular processes. Be it an enzyme catalysis ('classic type functions' of proteins) or a signal transduction ('non-classic'), proteins generally function involving stable or quasi-stable multi-protein associations. The physical basis for such associations is inherent in the combined effect of shape and electrostatic complementarities (Sc, EC) of the interacting protein partners at their interface, which provides indirect probabilistic estimates of the stability and affinity of the interaction. While Sc is a necessary criterion for inter-protein associations, EC can be favorable as well as disfavored (e.g., in transient interactions). Estimating equilibrium thermodynamic parameters (∆Gbinding, Kd) by experimental means is costly and time consuming, thereby opening windows for computational structural interventions. Attempts to empirically probe ∆Gbinding from coarse-grain structural descriptors (primarily, surface area based terms) have lately been overtaken by physics-based, knowledge-based and their hybrid approaches (MM/PBSA, FoldX, etc.) that directly compute ∆Gbinding without involving intermediate structural descriptors. METHODS: Here, we present EnCPdock ( https://www.scinetmol.in/EnCPdock/ ), a user-friendly web-interface for the direct conjoint comparative analyses of complementarity and binding energetics in proteins. EnCPdock returns an AI-predicted ∆Gbinding computed by combining complementarity (Sc, EC) and other high-level structural descriptors (input feature vectors), and renders a prediction accuracy comparable to the state-of-the-art. EnCPdock further locates a PPI complex in terms of its {Sc, EC} values (taken as an ordered pair) in the two-dimensional complementarity plot (CP). In addition, it also generates mobile molecular graphics of the interfacial atomic contact network for further analyses. EnCPdock also furnishes individual feature trends along with the relative probability estimates (Prfmax) of the obtained feature-scores with respect to the events of their highest observed frequencies. Together, these functionalities are of real practical use for structural tinkering and intervention as might be relevant in the design of targeted protein-interfaces. Combining all its features and applications, EnCPdock presents a unique online tool that should be beneficial to structural biologists and researchers across related fraternities.

Improved valorization of sewage sludge in the circular economy by anaerobic digestion: Impact of an innovative pretreatment technology.

Anaerobic digestion (AD) of sewage sludge shows low carbon conversion efficiency (CCE) due to the poor biodegradability of sewage sludge. The lack of digestibility is specifically linked to the waste-activated sludge (WAS) making up the majority of sewage sludge along with a smaller portion of primary sludge, depending on the wastewater treatment plant configuration. In this study, we examine the Advanced Wet Oxidation & Steam Explosion process (AWOEx) for improving the CCE of digested sewage sludge (DSS) by thermophilic AD. The effect of the pretreatment temperature in the range between 160 and 185 °C at a fixed residence time of 20 min with and without oxygen added at a dosage of 5 % of the organics present was tested. Methane yield improved by 97.92 % to 183.91 ± 4.93 mL/g vS over the untreated DSS (control), whose methane yield was 92.92 ± 9.07 mL/g vS We have demonstrated for the first time that 84 % of the organics in sewage sludge can successfully be transformed into biogas following AWOEx pretreatment, which can contribute significantly to the circular economy instead of greenhouse gas emissions from landfilling.

Bioaugmentation of Methanosarcina thermophila grown on biochar particles during semi-continuous thermophilic food waste anaerobic digestion under two different bioaugmentation regimes.

This study presents the effect of bioaugmentation of thermophilic anaerobic digestion of food waste with Methanosarcina thermophila grown on a wood-derived biochar. Two different supplementation regimes were tested, namely a single bioaugmentation (SBABC) in which 10% v/v of the microbes grown on biochar (1 g/L) is added at setup of the reactors, versus a routine bioaugmentation (RBABC) wherein the same amount of supplements were added over 10 feeding cycles. The optimally performing 'R' and 'S' reactors had increased methane yields by 37% and 32% over their respective controls while reactors SBABC 2 and 3 produced 21.89% and 56.09% higher average methane yield than RBABC 2 and 3, respectively. It appears that a single dose bioaugmentation is advantageous for improving AD as analysed in terms of average methane yield and VFA production. This study provides the basis for understanding how biochar and bioaugmentation can be used for engineering sustainable pilot-scale AD processes.

Current challenges of hydrothermal treated wastewater (HTWW) for environmental applications and their perspectives: A review.

Hydrothermal treatment (HT) is an emerged thermochemical approach for the utilization of biomass. In the last decade, intense research has been conducted on bio-oil and hydrochar, during which extensive amount of hydrothermal treated wastewater (HTWW) is produced, containing large amount of organic compounds along with several toxic chemicals. The composition of HTWW is highly dependent on the process conditions and organic composition of biomass, which determines its further utilization. The current study provides a comprehensive overview of recent advancements in HTWW utilization and its properties which can be changed by varying different parameters like temperature, residence time, solid concentration, mass ratio and catalyst including types of biomasses. HTWW characterization, parameters, reaction mechanism and its application were also summarized. By considering the challenges of HTWW, some suggestions and proposed methodology to overcome the bottleneck are provided.

Degrading chlorinated aliphatics by reductive dechlorination of groundwater samples from the Santa Susana Field Laboratory.

Microbial reductive dechlorination is one of the chosen methods for remediation of chlorinated compounds in anaerobic environments. In this study we examined the degradation of chlorinated aliphatics in groundwater samples from the Santa Susana Field Laboratory (SSFL) containing a concentration of 0.228 mM trichloroethylene (TCE) and 0.279 mM 1,2 dichloroethylene (DCE). We tested the influence of adding different carbon sources on the dechlorinating activity in batch cultures with and without dechlorinating bacteria. In-situ microcosms were established using SSFL groundwater supplemented with EVO (5%) (vol/vol) SRS emulsion and with or without species of Dehalocococcoides (DCB-1, DCB-2 or DCB-3). Emulsified vegetable oil (EVO) gave the highest dechlorinating activity with DCB-1 added compared to any other substrate addition tested. All three bacterial cultures tested had significant dechlorinating activities while the native populations in the SSFL groundwater samples only showed limited degradation of trichloroethylene into intermediates in the form of DCE, vinyl chloride and ethane. The conversion of chlorinated ethylenes (CEs) was optimal in the bioreactors amended with DCB-1 followed by DCB-2, and DCB-3 all supplemented with EVO. We further analyzed the TCE degradation first order kinetics in batch cultures and found that the culture with DCB-1 supplemented with EVO showed 43.59% and 51.38% increased degradation rate compared to the same condition with cultures of DCB-2 or DCB-3 added. The microcosm studies further showed that with DCB-1 and EVO, reductive dechlorination of TCE in the SSFL converted 90% of the input TCE to ethane with a degradation rate of 0.0039 mM/day.

Soybean Processing Wastes: Novel Insights on Their Production, Extraction of Isoflavones, and Their Therapeutic Properties.

Soybean processing waste (SPW) has potential as a sustainable source of phytochemicals and functional foods. A variety of phytochemicals, nutrients, and minerals have been characterized from SPW using various analytical methods. SPW utilization strategies may provide a new way to increase production of bioactive compounds, nutritional supplements, and cosmetic ingredients. SPW has the potential for value-added processing, to improve commercial use, and to lower environmental pollution through proper use. Okara, a byproduct generated during soybean processing of tofu and soy milk, is rich in dietary fiber, isoflavones, and saponins. Isoflavones, an important class of biologically active compounds owing to their multifunctional and therapeutic effects, are extracted from SPW. Further, studies have shown that okara has potential prebiotic and therapeutic value in lowering the risk of noncommunicable diseases. Therefore, in this review, we focus on several extraction methods and pharmacotherapeutic effects of different SPWs. Their effective uses in functional foods, nutraceuticals, and health applications, as biocatalysts, and as value-added resources have been discussed.

Heterologous expression and biophysical characterization of a mesophilic tannase following manganese nanoparticle immobilization.

In the current study, we analyzed the efficacy of manganese oxide nanoparticle (MnNP)-water dispersion as an immobilization matrix for bacterial tannase. The tannase-secreting Bacillus subtilis strain NJKL.tan.2 obtained from tannery effluent soil was subsequently purified and cloned in pET20b vector. The activity of MnNP-tan (tannase activated by manganese nanoparticles) was 1.51- and 3.5-fold higher at 20 °C and 80 °C, respectively, compared with the free enzyme. MnNP-tan decreased Km by 41.66 % and 3-fold, whereas free tannase showed two-fold and six-fold improvement in Kcat at 37 °C and 80 °C, respectively. MnNP-tan showed an increase in (half-life)t1/2and Ed by 13-fold and 50.05 units, respectively, at 80 °C, in contrast to the native enzyme. MnNP-tan retained its residual activity by 78.2 % at 37 °C and 34.24 % at 80 °C after 180 min of incubation when compared with untreated set. MnNP-tan retained 51 % of its activity after 120 days with the native enzyme losing ∼50 % functionality following 40 days of incubation. The MnNP-mediated tannase immobilization technique is being reported for the first time. The technique has numerous advantages due to the use of MnNP as a potential matrix for biomolecule immobilization, which can be further extended to immobilize other biocatalysts used in agro-industrial and lab-based applications.

Mother-to-child HIV transmission and its correlates in India: systematic review and meta-analysis.

BACKGROUND: In India, preventing mother-to-child transmission (PMTCT) of Human Immunodeficiency Virus (HIV) remains one of the foremost challenge in community health. Countrywide MTCT of HIV is estimated to be > 10,000 annually. Aims of present study are to find out the prevalence of HIV and correlates of HIV transmission among children given birth by HIV infected mother through systematic review along with meta-analysis. METHODS: All avaiable articles are retrieved using MEDLINE, Cochrane Library, Science Direct, EMBASE, Google Scholar and PUBMED following guidelines for Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Joanna Briggs Institute Meta-Analysis of Statistics Assessment and Review Instrument (JBI-MAStARI) are applied to critically reviewing the selected articles. STATA 13.0 is used to preparation of forest plot for Meta-analysis. For assessment of heterogeneity and publication biases I2 statistics along with Begg and Mazumdar's test and Egger's tests are used. Odds ratio (OR) along with forest plots have been showing with 95% confidence interval (CI). RESULTS: All together 10 studies including 1537 pairs of mothers and new births are assessed in present meta-analysis. Present analysis revealed the prevalence of HIV due to MTCT in India as 8.76% (95% CI; 5.76, 12.31). Analysis of subgroups exhibit a higher pooled prevalence in eastern region of India, 10.83% (95% CI: 5.9, 17.81) and lower in in Western region in India, 6.37% (95% CI: 4.65, 8.49). Status of MTCT before and after initiation of universal ART are 10.23% (95% CI 6.61, 14.55) and 7.93% (95% CI 4.18, 12.76) respectively. Associated factors with MTCT of HIV include absence of maternal prevention of MTCT intervention, OR = 10.82 (95% CI: 5.28, 22.17), lacking in administration of infant ARV (antiretroviral), OR = 8.21 (95% CI: 4.82, 14.0) and absence of medical facility during childbirth OR = 3.73 (95% CI: 1.67, 8.33). CONCLUSIONS: In India, pooled HIV prevalence of MTCT as high as 8.78% (95% CI; 5.76, 12.31) among babies born to infected mothers warrants urgent need of focused intervention for providing ART (PMTCT intervention), ensuring proper infant ARV prophylaxis, and avoiding delivery without proper medical facility to pregnant women with HIV for reduction of occurrence in HIV transmission from mothers to children.

HIV Care Among Elderly Population: Systematic Review and Meta-Analysis.

Elderly people living with HIV are increasing. At present in the United States, nearly half of newly diagnosed HIV-infected people are aged >50 years. Diagnosis and treatment of HIV-infected elderly patients tends to be delayed by several health care factors as several life-threatening diseases are common in elderly people. This study aimed to find the pooled HIV prevalence in elderly population and the present situation of continuum care for the elderly HIV patients through systematic review and meta-analysis. All previously published articles from 2000 to 2018 are retrieved using MEDLINE, PUBMED, Cochrane Library, EMBASE, and Google Scholar. DerSimonian and Laird Random Effects model are used to critically appraise articles. STATA 13.0 is used to perform the meta-analysis and quantum-geographic information system (Q-GIS) is used to prepare desired map. I2 statistics has been used to test heterogeneity and publication biases. Results have been presented using forest plots. A total of 28 studies are included in this meta-analysis. Present analysis revealed pooled prevalence of HIV in elderly population as 15.79% with a lower rate of viral suppression as 11.524% (95% confidence interval, CI: 11.199-11.855), where a moderate number 38.643% (95% CI: 38.289-38.997) of elderly patients received antiretroviral therapy (ART) globally. The ART retention rate was 12.769% (95% CI: 12.540-13.001) with 6.15% (95% CI: 6.089-6.212) mortality. Despite successful administration of ART in developing part of the world that have relatively higher retention rates among HIV-infected elderly patients only a small percentage are virally suppressed, largely due to elderly drugs interact with ART and several comorbidities reduce the life span of the elderly people.

Nanoparticle-induced enzyme pretreatment method for increased glucose production from lignocellulosic biomass under cold conditions.

BACKGROUND: Appropriate pretreatment strategies that fractionate sugarcane bagasse (SB) are essential for the successful use of this feedstock in ethanol production. In this paper, we investigate a purely enzymatic process to achieve increased production of reducing sugars (RS) from SB in the presence of MgO nanoparticles (MgN) subjected to a three-step sequential enzyme treatment. RESULT: Pretreatment of SB with protease activated by magnesium oxide nanoparticles (MgN-pro) at 95 °C showed an increase in amino acid production by 6.18-fold compared to the untreated enzyme set at the same temperature. High-performance liquid chromatography (HPLC) studies showed an 18-fold removal of lignin from the samples subjected to protease (+ MgN) treatment compared to untreated samples. When the MgN-pro pretreated samples were subjected to pretreatment with xylanase activated by magnesium oxide nanoparticles (MgN-xyl), more than 30-fold increased RS was produced at 8 °C compared to cellulase (cel) pretreated samples. Xylanase pretreated SB samples produced 1.82- and 1.91-fold increased reducing sugar and glucose respectively at 8 °C in the presence of MgN compared to untreated samples at the same temperature. CONCLUSION: The results presented here show the efficiency of the proposed method for improving the enzymatic digestibility of SB and explain the pretreatment action mechanism. These findings have potential implications in bio-ethanol, bio-fuel, and agro industries. © 2018 Society of Chemical Industry.

Immobilization of a Mesophilic Lipase on Graphene Oxide: Stability, Activity, and Reusability Insights.

Catalyst-mediated bioprocessing at an industrial scale is dependent on the sustained stability and activity of the biocatalyst. Here, we demonstrate that strategy employed to increase the stability and activity of a mesophilic lipase immobilized on graphene oxide (GO). The protein adsorption capacity of GO is much higher than of other large surface area carbonaceous materials. Its structure and physicochemical properties are reported beneficial for enzymatic activity modifications. A purified lipase from Brevibacillus borstelensis NLIP05 immobilized on GO showed remarkable increase in thermostability (at 95°C) over a broad alkaline pH range (pH 7-12) compared to the free enzyme. Thermodynamic analysis of the GO-lip showed decreases in Km and activation energy (Ea) with increased Vmax and deactivation energy (Ed) at both 45 and 95°C. The decrease in decay constant (k) coupled with the increase in t1/2 value with temperature increase were salient features of the GO-lip system. This implies that GO-based immobilization conferred structural stability to the enzyme at higher temperature indicating chaperone like activity. Our findings support suitability of immobilized lipase on GO nanosupport for possible production of value-added materials with varied biological applications in the form of active pharmaceutical substances, synthetic building blocks, and effective synthesis of surfactants. The enhanced stability and activity of lipase indicate major application of GO on an industrial scale.

Nano-magnesium aided activity enhancement and biophysical characterization of a psychrophilic α-amylase immobilized on graphene oxide nanosupport.

In the current literature we have devised an immobilization technique for conferring psychrostability to a cold active α-amylase (amy) enzyme by the use of magnesium nanoparticle (MgNP) and graphene oxide (GO). The GO-MgNP-amy nanocomposite showed enhanced enzymatic activity and thermostability at both upper (90°C) and lower (8°C) temperature extremes. The GO-MgNP-amy showed increased affinity towards substrate, reflected in the decrease in its Km by 2.35 and 14.9-fold at 8°C and 90°C, respectively, than the untreated enzyme. GO-MgNP-amy showed 2.34-fold and 4.29-fold increase in Vmax at 8°C and 90°C, respectively, than the untreated enzyme. When compared to native enzyme at 90°C, GO-MgNP-amy had t1/2 (half life) increased by 44-fold with simultaneous increase in Ed by 1.9-fold. Again at 8°C, GO-MgNP-amy had t1/2 increased by 6.48-fold with simultaneous increase in Ed by 2.21-fold when compared to the native enzyme. The enzymatic activity of GO-MgNP-amy was retained even after 12 repeated uses and showed storage stability at 4°C for more than 120 days. The ability of GO-MgNP to sustain and aggravate enzyme activity and stability at temperatures beyond the optimal range can be utilized in bioprocessing industries which requires functioning at these extreme ranges of temperature.

Improved production of reducing sugars from rice husk and rice straw using bacterial cellulase and xylanase activated with hydroxyapatite nanoparticles.

Purified bacterial cellulase and xylanase were activated in the presence of calcium hydroxyapatite nanoparticles (NP) with concomitant increase in thermostability about 35% increment in production of d-xylose and reducing sugars from rice husk and rice straw was obtained at 80°C by the sequential treatment of xylanase and cellulase enzymes in the presence of NP compared to the untreated enzyme sets. Our findings suggested that if the rice husk and the rice straw samples were pre-treated with xylanase prior to treatment with cellulase, the percentage increase of reducing sugar per 100g of substrate (starting material) was enhanced by about 29% and 41%, respectively. These findings can be utilized for the extraction of reducing sugars from cellulose and xylan containing waste material. The purely enzymatic extraction procedure can be substituted for the harsh and bio-adverse chemical methods.

Nanotechnology enabled enhancement of enzyme activity and thermostability: study on impaired pectate lyase from attenuated Macrophomina phaseolina in presence of hydroxyapatite nanoparticle.

In this paper we show that hydroxyapatite nanoparticles (NP) can not only act as a chaperon (by imparting thermostability) but can serve as a synthetic enhancer of activity of an isolated extracellular pectate lyase (APL) with low native state activity. The purified enzyme (an attenuated strain of Macrophomina phaseolina) showed feeble activity at 50°C and pH 5.6. However, on addition of 10.5 µg/ml of hydroxyapatite nanoparticles (NP), APL activity increased 27.7 fold with a 51 fold increase in half-life at a temperature of 90°C as compared to untreated APL. The chaperon like activity of NP was evident from entropy-enthalpy compensation profile of APL. The upper critical temperature for such compensation was elevated from 50°C to 90°C in presence of NP. This dual role of NP in enhancing activity and conferring thermostability to a functionally impaired enzyme is reported for the first time.

Degumming of ramie fiber and the production of reducing sugars from waste peels using nanoparticle supplemented pectate lyase.

Banana, citrus and potato peels were subjected to treatment with hydroxyapatite nanoparticle (NP) supplemented purified pectate lyase (NP-PL), isolated from Bacillus megaterium AK2 to produce reducing sugar (RS). At both 50 and 90°C production of RS by NP-PL was almost twofold greater than that by untreated pectate lyase (PL) from each of the three peels. The optimal production of RS from banana and citrus peels were after 24 and 6h of incubation while it was 24 and 4h for potato peels at 50 and 90°C, respectively, on NP-PL treatment. NP-PL could degum raw, decorticated ramie fibers as well as enhance fiber tenacity and fineness. The weight loss of the fibers were 24% and 31% better (compared to PL treatment) after 24 and 48 h of processing. These findings have potential implications for the bio-ethanol, bio-fuel and textile industries.