Phosphorus recovery potential from sewage sludge by struvite precipitation: remodelling policy framework in Rajasthan, India.

The manufacturing of fossil-based fertilizers by extraction of rock phosphate has contributed to carbon emissions and depleted the non-renewable phosphorus reserves. Sewage sludge, which is a waste product from Sewage Treatment Plants (STPs), is rich in phosphorus. The existing techniques for sludge management contribute to carbon emissions and ecological footprint. Struvite (raw fertilizer) and biochar recovery from sludge has emerged as viable methods to reduce carbon emission and ensure economic sustainability of STPs. In this work, the potential for phosphorus recovery and revenue generation is discussed for Rajasthan state in India. The fate of phosphorus and heavy metals in STPs is evaluated which indicates that about 70% of the phosphorus and trace amounts of metals end up in sewage sludge. Further, the power consumption is high in STPs due to industrial wastewater ingress. There is a need to bridge the gap between sewage treatment and generation in Rajasthan, improve STP performance before resource recovery inclusion at policy-level and scale-up. Mixing struvite with biochar can lead to safe application of struvite as raw fertilizer as heavy metals are sequestered by biochar. A business framework is developed to serve as a blueprint and potential model for linking technical and market viability.

Cimicifugin, a broad-spectrum inhibitor of Theileria annulata and Plasmodium falciparum CDK7.

Cyclin-dependent kinase 7 is an attractive therapeutic target for the treatment of cancers, and a previous report suggested that Plasmodium falciparum CDK7 is a potential drug target for developing new anti-malarial drugs. In this study, we aimed to characterize and evaluate the drug target potential of Theileria annulata CDK7. Theileria annulata is responsible for tropical theileriosis, which induces a phenotype similar to cancerous cells like immortalization, hyperproliferation, and dissemination. Virtual screening of the MyriaScreen II library predicted 14 compounds with high binding energies to the ATP-binding pocket of TaCDK7. Three compounds (cimicifugin, ST092793, and ST026925) of these 14 compounds were non-cytotoxic to the uninfected bovine cells (BoMac cells). Cimicifugin treatment led to the activation of the extrinsic apoptosis pathway and induced autophagy in T. annulata-infected cells. Furthermore, cimicifugin also inhibited the growth of P. falciparum, indicating that it has both anti-theilerial and anti-malarial activities and that TaCDK7 and PfCDK7 are promising drug targets.

Oleuropein activates autophagy to circumvent anti-plasmodial defense.

Antimalarial drug resistance and unavailability of effective vaccine warrant for newer drugs and drug targets. Hence, anti-inflammatory activity of phyto-compound (oleuropein; OLP) was determined in antigen (LPS)-stimulated human THP-1 macrophages (macrophage model of inflammation; MMI). Reduction in the inflammation was controlled by the PI3K-Akt1 signaling to establish the "immune-homeostasis." Also, OLP treatment influenced the cell death/autophagy axis leading to the modulated inflammation for extended cell survival. The findings with MII prompted us to detect the antimalarial activity of OLP in the wild type (3D7), D10-expressing GFP-Atg18 parasite, and chloroquine-resistant (Dd2) parasite. OLP did not show the parasite inhibition in the routine in vitro culture of P. falciparum whereas OLP increased the antimalarial activity of artesunate. The molecular docking of autophagy-related proteins, investigations with MMI, and parasite inhibition assays indicated that the host activated the autophagy to survive OLP pressure. The challenge model of P. berghei infection showed to induce autophagy for circumventing anti-plasmodial defenses.

Development of diphenylmethylpiperazine hybrids of chloroquinoline and triazolopyrimidine using Petasis reaction as new cysteine proteases inhibitors for malaria therapeutics.

Malaria is a widespread infectious disease, causing nearly 247 million cases in 2021. The absence of a broadly effective vaccine and rapidly decreasing effectiveness of most of the currently used antimalarials are the major challenges to malaria eradication efforts. To design and develop novel antimalarials, we synthesized a series of 4,7-dichloroquinoline and methyltriazolopyrimidine analogues using a multi-component Petasis reaction. The synthesized molecules (11-31) were screened for in-vitro antimalarial activity against drug-sensitive and drug-resistant strains of Plasmodium falciparum with an IC50 value of 0.53 µM. The selected compounds were screened to evaluate in-vitro and in-silico enzyme inhibition efficacy against two cysteine proteases, PfFP2 and PfFP3. The compounds 15 and 17 inhibited PfFP2 with an IC50 = 3.5 and 4.8 µM, respectively and PfFP3 with an IC50 = 4.9 and 4.7 µM, respectively. Compounds 15 and 17 were found equipotent against the Pf3D7 strain with an IC50 value of 0.74 µM, whereas both were displayed IC50 values of 1.05 µM and 1.24 µM for the PfW2 strain, respectively. Investigation of effect of compounds on parasite development demonstrated that compounds were able to arrest the growth of the parasites at trophozoite stage. The selected compounds were screened for in-vitro cytotoxicity against mammalian lines and human red-blood-cell (RBC), which demonstrated no significant cytotoxicity associated with the molecules. In addition, in silico ADME prediction and physiochemical properties supported the drug-likeness of the synthesized molecules. Thus, the results highlighted the diphenylmethylpiperazine group cast on 4,7-dichloroquinoline and methyltriazolopyrimidine using Petasis reaction may serve as models for the development of new antimalarial agents.

Plasmodium DDI1 is a potential therapeutic target and important chromatin-associated protein.

DNA damage inducible 1 protein (DDI1) is involved in a variety of cellular processes including proteasomal degradation of specific proteins. All DDI1 proteins contain a ubiquitin-like (UBL) domain and a retroviral protease (RVP) domain. Some DDI1 proteins also contain a ubiquitin-associated (UBA) domain. The three domains confer distinct activities to DDI1 proteins. The presence of a RVP domain makes DDI1 a potential target of HIV protease inhibitors, which also block the development of malaria parasites. Hence, we investigated the DDI1 of malaria parasites to identify its roles during parasite development and potential as a therapeutic target. DDI1 proteins of Plasmodium and other apicomplexan parasites share the UBL-RVP domain architecture, and some also contain the UBA domain. Plasmodium DDI1 is expressed across all the major life cycle stages and is important for parasite survival, as conditional depletion of DDI1 protein in the mouse malaria parasite Plasmodium berghei and the human malaria parasite Plasmodium falciparum compromised parasite development. Infection of mice with DDI1 knock-down P. berghei was self-limiting and protected the recovered mice from subsequent infection with homologous as well as heterologous parasites, indicating the potential of DDI1 knock-down parasites as a whole organism vaccine. Plasmodium falciparum DDI1 (PfDDI1) is associated with chromatin and DNA-protein crosslinks. PfDDI1-depleted parasites accumulated DNA-protein crosslinks and showed enhanced susceptibility to DNA-damaging chemicals, indicating a role of PfDDI1 in removal of DNA-protein crosslinks. Knock-down of PfDDI1 increased susceptibility to the retroviral protease inhibitor lopinavir and antimalarial artemisinin, which suggests that simultaneous inhibition of DDI1 could potentiate antimalarial activity of these drugs. As DDI1 knock-down parasites confer protective immunity and it could be a target of HIV protease inhibitors, Plasmodium DDI1 is a potential therapeutic target for malaria control.

Management of reject water in decentralized community RO plants by devising an integrated treatment scheme of NF and RO by pilot-scale analysis.

Community RO plants have been installed in the semi-arid state of Rajasthan in India to provide potable water to the scattered rural settlements by treatment of brackish groundwater. Presently, these are using standalone RO systems which are operating at low recovery along with the problem of early membrane scaling. To ensure sustainability and maximize the recovery of fresh water, hybrid configurations of membrane processes must be evaluated. In this work, it is aimed to design a conclusive hybrid scheme of NF and RO to deliver maximum freshwater recovery. Firstly, the individual performance of NF and RO in a two-pass NF-RO configuration is evaluated i.e., the removal of ions with respect to feed concentration, ionic radius and hydration radius. The removal efficiency was 85% for sulphate, 54% for calcium and 56% for magnesium by NF. The scaling potential of the water greatly reduced as indicated by the LSI and RSI values by NF pre-treatment. The characterization of RO and NF by FESEM-EDS and FTIR Spectroscopy showed numerous peaks in NF as compared to RO corresponding to inorganic scaling. The specific energy consumption for NF, RO and two-pass NF-RO was 0.13-0.27 kWh/m3, 0.04-0.08 kWh/m3 and 0.17-0.35 kWh/m3, respectively. Based on the performance of standalone NF, RO and two pass NF-RO, mathematical simulations were performed to derive best configurations for NF-RO integration. The resulting configuration, a two stage RO-NF with NF permeate blending to the raw water, resulted in a recovery of 70-80% which was ∼50% higher than the two-pass NF-RO scheme.

The role of pharmaceutical industry in building resilient health system.

Objectives: This study explores the interrelationship among the current sustainability agenda of the pharmaceutical industry, based on the United Nation sustainable development goals (SDGs), the elements of the Joint External Evaluation (JEE) tool, and the triad components of the One Health approach. Methods: A cross-walk exercise was conducted to identify commonalities among SDGs, JEE assessment tool, and One Health approach. An in-depth study of 10 global pharmaceutical firms' corporate sustainability reports and COVID-19 response plan for 2019-2020 was also conducted. Results: The result of the exercise showed the existence of a direct and indirect relationship among the SDGs, elements of JEE assessment tool, and One Health approach. For example, both no poverty (SDG 1) and zero hunger (SDG 2) are linked with food safety targets under the JEE and with human and animal health under the One Health approach. Conclusion: This study adds a new dimension emphasizing the possibility of tailoring the pharmaceutical industry's activities under the sustainability agenda to strengthen global health security while remaining consistent with the One Health approach.

Experimental investigation and modelling the effect of humic acid on coagulation efficiency for sludge blanket clarifier.

The physicochemical process of coagulation has largely been used for turbidity removal for water treatment. However, lately, the intrusion of NOM (Natural organic matter) in the surface water sources due to climate change has impeded the dosing approaches and has presented a requirement to evaluate the effect of NOM on turbidity removal efficiency and the performance of coagulation reactors in general. In this work, a previously developed performance model for hydraulic flocculators was modified and tested for a sludge blanket clarifier (SBC) which is a type of hydraulic flocculator. The experimental runs were conducted by preparing synthetic sample waters by using humic acid (for NOM) and kaolin clay (for turbidity). PACl (Poly aluminium chloride) was used as a coagulant. The expression of attachment efficiency has been modified to include the interactions of humic acid (HA) and kaolin, which were not previously accounted for in the model. The coverage functions were used to calculate the attachment efficiency of HA-PACl and PACl-Clay. The standalone coverage function ГPACl-HA efficiently predicted the doses where the removal efficiency was maximum. However, the coverage function ГClay-PACl was impacted by the hydrodynamic conditions in SBC and over-speculated the Clay-PACl interactions. The RMSE value was low for the modified equation indicating that in SBC the interactions between the organic and inorganic impurities are significant. The HA-Kaolin interactions were found to be significant in the modified model in case of a low HA range of 4 and 8 mg/L of HA.

Distinct metabolic states of a cell guide alternate fates of mutational buffering through altered proteostasis.

Metabolic changes alter the cellular milieu; can this also change intracellular protein folding? Since proteostasis can modulate mutational buffering, if change in metabolism has the ability to change protein folding, arguably, it should also alter mutational buffering. Here we find that altered cellular metabolic states in E. coli buffer distinct mutations on model proteins. Buffered-mutants have folding problems in vivo and are differently chaperoned in different metabolic states. Notably, this assistance is dependent upon the metabolites and not on the increase in canonical chaperone machineries. Being able to reconstitute the folding assistance afforded by metabolites in vitro, we propose that changes in metabolite concentrations have the potential to alter protein folding capacity. Collectively, we unravel that the metabolite pools are bona fide members of proteostasis and aid in mutational buffering. Given the plasticity in cellular metabolism, we posit that metabolic alterations may play an important role in cellular proteostasis.

Classification of chemical chaperones based on their effect on protein folding landscapes.

Various small molecules present in biological systems can assist protein folding in vitro and are known as chemical chaperones. De novo design of chemical chaperones with higher activity than currently known examples is desirable to ameliorate protein misfolding and aggregation in multiple contexts. However, this development has been hindered by limited knowledge of their activities. It is thought that chemical chaperones are typically poor solvents for a protein backbone and hence facilitate native structure formation. However, it is unknown if different chemical chaperones can act differently to modulate folding energy landscapes. Using a model slow folding protein, double-mutant Maltose-binding protein (DM-MBP), we show that a canonical chemical chaperone, trimethylamine-N-oxide (TMAO), accelerates refolding by decreasing the flexibility of the refolding intermediate (RI). Among a number of small molecules that chaperone DM-MBP folding, proline and serine stabilize the transition state (TS) enthalpically, while trehalose behaves like TMAO and increases the rate of barrier crossing through nonenthalpic processes. We propose a two-group classification of chemical chaperones based upon their thermodynamic effect on RI and TS, which is also supported by single molecule Förster resonance energy transfer (smFRET) studies. Interestingly, for a different test protein, the molecular mechanisms of the two groups of chaperones are not conserved. This provides a glimpse into the complexity of chemical chaperoning activity of osmolytes. Future work would allow us to engineer synergism between the two classes to design more efficient chemical chaperones to ameliorate protein misfolding and aggregation problems.

Chemical chaperones assist intracellular folding to buffer mutational variations.

Hidden genetic variations have the potential to lead to the evolution of new traits. Molecular chaperones, which assist protein folding, may conceal genetic variations in protein-coding regions. Here we investigate whether the chemical milieu of cells has the potential to alleviate intracellular protein folding, a possibility that could implicate osmolytes in concealing genetic variations. We found that the model osmolyte trimethylamine N-oxide (TMAO) can buffer mutations that impose kinetic traps in the folding pathways of two model proteins. Using this information, we rationally designed TMAO-dependent mutants in vivo, starting from a TMAO-independent protein. We show that different osmolytes buffer a unique spectrum of mutations. Consequently, the chemical milieu of cells may alter the folding pathways of unique mutant variants in polymorphic populations and lead to unanticipated spectra of genetic buffering.