Towards a Rigorous Network of Protein-Protein Interactions of the Model Sulfate Reducer Desulfovibrio vulgaris Hildenborough

Protein–protein interactions offer an insight into cellular processes beyond what may be obtained by the quantitative functional genomics tools of proteomics and transcriptomics. The aforementioned tools have been extensively applied to study Escherichia coli and other aerobes and more recently to study the stress response behavior of Desulfovibrio vulgaris Hildenborough, a model obligate anaerobe and sulfate reducer and the subject of this study. Here we carried out affinity purification followed by mass spectrometry to reconstruct an interaction network among 12 chromosomally encoded bait and 90 prey proteins based on 134 bait-prey interactions identified to be of high confidence. Protein-protein interaction data are often plagued by the lack of adequate controls and replication analyses necessary to assess confidence in the results, including identification of potential false positives. We addressed these issues through the use of biological replication, exponentially modified protein abundance indices, results from an experimental negative control, and a statistical test to assign confidence to each putative interacting pair applicable to small interaction data studies. We discuss the biological significance of metabolic features of D. vulgaris revealed by these protein-protein interaction data and the observed protein modifications. These include the distinct role of the putative carbon monoxide-induced hydrogenase, unique electron transfer routes associated with different oxidoreductases, and the possible role of methylation in regulating sulfate reduction

Evolution and epidemic spread of SARS-CoV-2 in Brazil

Brazil currently has one of the fastest-growing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) epidemics in the world. Because of limited available data, assessments of the impact of nonpharmaceutical interventions (NPIs) on this virus spread remain challenging. Using a mobility-driven transmission model, we show that NPIs reduced the reproduction number from >3 to 1 to 1.6 in São Paulo and Rio de Janeiro. Sequencing of 427 new genomes and analysis of a geographically representative genomic dataset identified >100 international virus introductions in Brazil. We estimate that most (76%) of the Brazilian strains fell in three clades that were introduced from Europe between 22 February and 11 March 2020. During the early epidemic phase, we found that SARS-CoV-2 spread mostly locally and within state borders. After this period, despite sharp decreases in air travel, we estimated multiple exportations from large urban centers that coincided with a 25% increase in average traveled distances in national flights. This study sheds new light on the epidemic transmission and evolutionary trajectories of SARS-CoV-2 lineages in Brazil and provides evidence that current interventions remain insufficient to keep virus transmission under control in this country

Genomics and epidemiology of the P.1 SARS-CoV-2 lineage in Manaus, Brazil

Cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in Manaus, Brazil, resurged in late 2020 despite previously high levels of infection. Genome sequencing of viruses sampled in Manaus between November 2020 and January 2021 revealed the emergence and circulation of a novel SARS-CoV-2 variant of concern. Lineage P.1 acquired 17 mutations, including a trio in the spike protein (K417T, E484K, and N501Y) associated with increased binding to the human ACE2 (angiotensin-converting enzyme 2) receptor. Molecular clock analysis shows that P.1 emergence occurred around mid-November 2020 and was preceded by a period of faster molecular evolution. Using a two-category dynamical model that integrates genomic and mortality data, we estimate that P.1 may be 1.7- to 2.4-fold more transmissible and that previous (non-P.1) infection provides 54 to 79% of the protection against infection with P.1 that it provides against non-P.1 lineages. Enhanced global genomic surveillance of variants of concern, which may exhibit increased transmissibility and/or immune evasion, is critical to accelerate pandemic responsiveness

Evolution and epidemic spread of SARS-CoV-2 in Brazil

Brazil currently has one of the fastest growing SARS-CoV-2 epidemics in the world. Owing to limited available data, assessments of the impact of non-pharmaceutical interventions (NPIs) on virus spread remain challenging. Using a mobility-driven transmission model, we show that NPIs reduced the reproduction number from >3 to 1–1.6 in São Paulo and Rio de Janeiro. Sequencing of 427 new genomes and analysis of a geographically representative genomic dataset identified >100 international virus introductions in Brazil. We estimate that most (76%) of the Brazilian strains fell in three clades that were introduced from Europe between 22 February11 March 2020. During the early epidemic phase, we found that SARS-CoV-2 spread mostly locally and within-state borders. After this period, despite sharp decreases in air travel, we estimated multiple exportations from large urban centers that coincided with a 25% increase in average travelled distances in national flights. This study sheds new light on the epidemic transmission and evolutionary trajectories of SARS-CoV-2 lineages in Brazil, and provide evidence that current interventions remain insufficient to keep virus transmission under control in the country

Immobilized Nanoparticles-Mediated Enzymatic Hydrolysis of Cellulose for Clean Sugar Production: A Novel Approach

Background: Enzymatic hydrolysis of cellulose is an expensive approach due to the high cost of an enzyme involved in the process. The goal of the current study was to apply magnetic nanomaterials as a support for immobilization of enzyme, which helps in the repeated use of immobilized enzyme for hydrolysis to make the process cost-effective. In addition, it will also provide stability to enzyme and increase its catalytic activity. Objective: The main aim of the present study is to immobilize cellulase enzyme on Magnetic Nanoparticles (MNPs) in order to enable the enzyme to be re-used for clean sugar production from cellulose. Methods: MNPs were synthesized using chemical precipitation methods and characterized by different techniques. Further, cellulase enzyme was immobilized on MNPs and efficacy of free and immobilized cellulase for hydrolysis of cellulose was evaluated. Results: Enzymatic hydrolysis of cellulose by immobilized enzyme showed enhanced catalytic activity after 48 hours compared to free enzyme. In first cycle of hydrolysis, immobilized enzyme hydrolyzed the cellulose and produced 19.5 ± 0.15 gm/L of glucose after 48 hours. On the contrary, free enzyme produced only 13.7 ± 0.25 gm/L of glucose in 48 hours. Immobilized enzyme maintained its stability and produced 6.15 ± 0.15 and 3.03 ± 0.25 gm/L of glucose in second and third cycle, respectively after 48 hours. Conclusion: This study will be very useful for sugar production because of enzyme binding efficiency and admirable reusability of immobilized enzyme, which leads to the significant increase in production of sugar from cellulosic materials. </jats:sec

Abstract 121: Role of Leukocyte Gpr120 in Atherosclerosis Development in Polyunsaturated Fatty Acid Diet Induced Atheroprotection in LDLrKO Mice

Introduction Diets enriched in polyunsaturated n-3 and n-6 fatty acids (PUFAs) are atheroprotective. FO, which is enriched in n-3 PUFAs, reduces plasma lipids and has anti-inflammatory effects. Recent studies have shown that GPR120 is the physiological n-3 PUFA receptor and its ligation by n-3 PUFAs blunts pro-inflammatory signaling pathways. However, the role of GRP120 in atherogenesis is unknown. Hypothesis We hypothesized that leukocyte GPR120 contributes to the atheroprotective effects of n-3, but not n-6, PUFUs by ligation of GRP120, resulting in decreased leukocyte inflammation. Methods Female LDLr-/- mice were transplanted with bone marrow from male wild type or GPR120 knockout mice. After recovery from transplantation, recipient LDLr-/- mice were fed atherogenic diets containing 0.2% cholesterol and enriched in saturated/monounsaturated fat (palm oil, PO), n-6 PUFA (borage, BO), a botanical n-3 PUFA (echium oil, EO) or FO for 16 weeks. Periodic blood samples were taken for lipid and lipoprotein measurements and aortas were harvested after 16 weeks of diet feeding to quantify atherosclerosis. Results Compared to the PO group, mice fed BO, EO and FO had significantly lower plasma total and very low density lipoprotein (VLDL) cholesterol concentrations. EO and FO groups also had lower plasma triglyceride concentrations compare to PO and BO fed mice. Compared to the PO group, mice fed BO and EO had significantly reduced aortic CE, comparable to the FO group. However, lack of leukocyte GPR120 did not significantly affect plasma lipids or atherosclerosis severity within any diet group. Conclusion Atherogenic diets enriched in n-6 and n-3 PUFAs derived from botanical oils (BO and EO) were as atheroprotective as FO compared to a diet containing saturated/monounsaturated fat (PO). Furthermore, lack of leukocyte GPR120 had minimal effect on plasma lipid/lipoprotein profile and atherosclerosis, suggesting that n-3 as well as n-6 PUFA associated atheroprotection is primarily due to reduction of VLDL-cholesterol in LDLr-/- mice. </jats:sec

Role of Nanoparticles in Enzymatic Hydrolysis of Lignocellulose in Ethanol

The depletion in the limited sources of fossil fuels has generated the problem of energy crisis all over the world. This hunt forces scientific community towards the search for cost-effective, environment-friendly, renewable alternative sources which can replace fossil fuels and fulfill the increasing demands of energy. In this context, the use of lignocellulosic material (plant residues) composed of cellulose, hemicellulose, and lignin becomes the first choice. In the process of ethanol production, first lignocellulosic material is broken down and hydrolyzed into simple sugars like cellulose, and then these sugars are fermented into biofuels such as ethanol in the presence of enzymes like cellulases. The use of cellulases makes the process expensive, and therefore, immobilization of these enzymes on solid supports like nanoparticles can help to recover the enzyme, which ultimately decreases the cost of process. Therefore, the use of nanotechnology and nanomaterials could be one possible avenue to improve biofuel production efficiency and reduction in the processing cost. This chapter discusses important existing pretreatment approaches involved in the pretreatment of plant biomass use for biofuel production. The emphasis is given on the role of nanotechnological solutions for the development of novel, efficient, and inexpensive strategies for the production of biofuels.St Gadge Baba Amravati Univ, Dept Biotechnol, Nanobiotechnol Lab, Amravati 444602, Maharashtra, IndiaUniv Sao Paulo, Engn Sch Lorena, Dept Biotechnol, Lorena, BrazilState Univ Sao Paulo UNESP, Inst Chem, Dept Biochem & Technol Chem, R Prof Francisco Degni 55, BR-14801060 Sao Paulo, BrazilState Univ Sao Paulo UNESP, Inst Chem, Dept Biochem & Technol Chem, R Prof Francisco Degni 55, BR-14801060 Sao Paulo, Brazi