Time-domain heart rate dynamics in the prognosis of progressive atherosclerosis.

BACKGROUND AND AIM: The regular uptake of a high-fat diet (HFD) with changing lifestyle causes atherosclerosis leading to cardiovascular diseases and autonomic dysfunction. Therefore, the current study aimed to investigate the correlation of autonomic activity to lipid and atherosclerosis markers. Further, the study proposes a support vector machine (SVM) based model in the prediction of atherosclerosis severity. METHODS AND RESULTS: The Lead-II electrocardiogram and blood markers were measured from both the control and the experiment subjects each week for nine consecutive weeks. The time-domain heart rate variability (HRV) parameters were derived, and the significance level was tested using a one-way Analysis of Variance. The correlation analysis was performed to determine the relation between autonomic parameters and lipid and atherosclerosis markers. The statistically significant time-domain values were used as features of the SVM. The observed results demonstrated the reduced time domain HRV parameters with the increase in lipid and atherosclerosis index markers with the progressive atherosclerosis severity. The correlation analysis revealed a negative association between time-domain HRV parameters with lipid and atherosclerosis parameters. The percentage accuracy increases from 86.58% to 98.71% with the increase in atherosclerosis severity with regular consumption of HFD. CONCLUSIONS: Atherosclerosis causes autonomic dysfunction with reduced HRV. The negative correlation between autonomic parameters and lipid profile and atherosclerosis indexes marker revealed the potential role of vagal activity in the prognosis of atherosclerosis progression. The support vector machine presented a respectable accuracy in the prediction of atherosclerosis severity from the control group.

Optimisation, characterization, and biological evaluation of novel exopolysaccharide from Bacillus licheniformis (BITSL006).

The study investigated production, characterisation, and biological properties of exopolysaccharide (EPS) from a thermophilic bacterium, Bacillus licheniformis using sucrose as a main carbon source at a temperature of 75 °C, resulting in a yield of 2.87 g/L. The surface topology of EPS was determined using FESEM indicating its porous nature. Subsequently, FTIR was employed to examine EPS and identified the presence of carboxyl and hydroxyl groups, which are believed to be associated with water-holding capacity (WHC). Comparing the FTIR spectrum of various exopolysaccharides, it was inferred that the exopolysaccharide derived from Ramkund closely resembles dextran. EDX and ICP-MS analysis revealed the presence of Sulphur and Selenium which might be involved in the anticancer properties of EPS. This is the first report on bacterial EPS from a hot spring (Ram kund) with antioxidant property, WHC, and high solubility. These properties offer beneficial resources for exploration in the pharmaceutical and agriculture industries.

Mutational analysis of flavonol synthase of M. pinnata towards enhancement of binding affinity: a computational approach.

Millettia pinnata is an important medicinal plant that has been used as a treatment of various diseases due to presence of wide range of pharmacological properties. The plant contains quercetin, kaempferol, karanjin, pongaglabrone, kanjone, kanugin, gammatin, pongaglabol, and other bioflavonoids. Kaempferol is a natural flavonol that shows many pharmacological properties including anti-inflammatory, antioxidant, anticancer, and antidiabetic activities etc. The enzyme flavonol synthase (FLS, EC 1.14.20.6) catalyses the conversion of dihydroflavonols to flavonols, i.e. biosynthesis of kaempferol from dihydrokaempferol. The current work examined the binding affinity-based approach to improve the enzyme catalytic activity using computational methods. Sequential site-directed mutagenesis was used to create four mutants with the goal to increase hydrogen bonds and further improving the ligand (dihydrokaempferol) binding efficiency. Simulations were done to monitor the stability of the mutants followed by molecular docking to confirm interactions with ligand. For structure validation, various dynamic analysis like RMSD, RMSF, ROG, SASA, H-bond, PCA, DCCM, and FEL were performed, which predicts the stability of wild-type (WT) proteins and mutants. The Mutant_2 and Mutant_3 showed maximum H-bonding and better stability than other mutants and WT that proved higher affinity suggesting improved catalysis. Mutant_2 and Mutant_3 exhibited binding affinities of -7.6 and -8.2 kcal/mol, respectively for the ligand. The outcome of present study will provide significant improvement in synthesis of kaempferol and other plant-based flavonoids.Communicated by Ramaswamy H. Sarma.

The molecular docking and molecular dynamics study of flavonol synthase and flavonoid 3'-monooxygenase enzymes involved for the enrichment of kaempferol.

Kaempferol is a natural flavonol that shows many pharmacological properties including anti-inflammatory, antioxidant, anticancer, antidiabetic activities etc. It has been reported in many vegetables, fruits, herbs and medicinal plants. The enzyme flavonol synthase (FLS, EC 1.14.20.6) catalyses the conversion of dihydroflavonols to flavonols. Whereas flavonoid 3'-monooxygenase (F3'H, EC 1.14.14.82) catalyses the hydroxylation of dihydroflavonol, and flavonol. FLS is involved in the synthesis of the kaempferol whereas F3'H causes degradation of kaempferol. The present study aimed to analyse the binding affinity, stability and activating activity of enzyme FLS as well as inhibitory activity of enzyme F3'H involved in the enrichment of the kaempferol using the in-silico approaches. Computational study for physico-chemical properties, conserved domain identification, 3-D structure prediction and its validation, conservation analysis, molecular docking followed by molecular dynamics analysis of FLS and F3'H, protein-activator (FLS-LIG Complex) and protein-inhibitor (F3'H-LIG Complex) complexes have been performed. Other structural analyses like root mean square fluctuation (RMSF), root mean square deviation (RMSD), surface area solvent accessibility (SASA), radius of gyration (Rg), hydrogen bond analysis, principal component analysis (PCA), Poisson-Boltzmann analysis (MM_PBSA) and the dynamic cross correlation map (DCCM) analysis to explore the structural, functional and thermodynamic stability of the proteins and the complexes were also studied. The molecular docking result showed that FLS binds strongly with the activator ascorbate (CID _54670067) while F3'H binds with the inhibitor ketoconazole (CID_456201). The most powerful inhibitor (ketoconazole for F3'H) and activator (ascorbate for FLS) is determined by computing the thermodynamic binding free energy through MM_PBSA analysis. The current work provides wide-ranging structural and functional information about FLS and F3'H enzymes showing detailed molecular mechanism of kaempferol biosynthesis and its degradation and hence kaempferol enrichment. Finding of the present work opens up new possibilities for future research towards enrichment of kaempferol by using activator (ascorbate) for FLS and inhibitor (ketoconazole) for F3'H as well as for its large-scale production using in vitro approaches.Communicated by Ramaswamy H. Sarma.

Heart rate dynamics in the prediction of coronary artery disease and myocardial infarction using artificial neural network and support vector machine.

BACKGROUND: Atherosclerosis leads to coronary artery disease (CAD) and myocardial infarction (MI), a major cause of morbidity and mortality worldwide. The computer-aided prognosis of atherosclerotic events with the electrocardiogram (ECG) derived heart rate variability (HRV) can be a robust method in the prognosis of atherosclerosis events. METHODS: A total of 70 male subjects aged 55 ± 5 years participated in the study. The lead-II ECG was recorded and sampled at 200 Hz. The tachogram was obtained from the ECG signal and used to extract twenty-five HRV features. The one-way Analysis of variance (ANOVA) test was performed to find the significant differences between the CAD, MI, and control subjects. Features were used in the training and testing of a two-class artificial neural network (ANN) and support vector machine (SVM). RESULTS: The obtained results revealed depressed HRV under atherosclerosis. Accuracy of 100% was obtained in classifying CAD and MI subjects from the controls using ANN. Accuracy was 99.6% with SVM, and in the classification of CAD from MI subjects using SVM and ANN, 99.3% and 99.0% accuracy was obtained respectively. CONCLUSIONS: Depressed HRV has been suggested to be a marker in the identification of atherosclerotic events. The good accuracy observed in classification between control, CAD, and MI subjects, revealed it to be a non-invasive cost-effective approach in the prognosis of atherosclerotic events.

Bio-fabrication of thermozyme-based nano-biosensors: their components and present scenario.

An amalgamation of microbiology, biocatalysis, recombinant molecular biology, and nanotechnology is crucial for groundbreaking innovation in developing nano-biomedicines and sensoristics. Enzyme-based nano-biosensor finds prospective applications in various sectors (environmental, pharmaceutical, food, biorefineries). These applications demand reliable catalytic efficiency and functionality of the enzyme under an extreme operational environment for a prolonged period. Over the last few years, bio-fabrication of nano-biosensors in conjunction with thermozymes from thermophilic microbes is being sought after as a viable design. Thermozymes are known for their robustness, are chemically resistant toward organic solvents, possess higher durability for constant use, catalytic ability, and stability at elevated temperatures. Additionally, several other attributes of thermozymes like substrate specificity, selectivity, and sensitivity make them desirable in developing a customized biosensor. In this review, crucial designing aspects of enzyme-based nano-biosensors like enzyme immobilization on an electrode surface, new materials derived from microbial sources (biopolymers based nanocomposites), improvisation measures for sensitivity, and selectivity have been addressed. It also covers microbial biosynthesis of nanomaterials used to develop sensoristic devices and its numerous applications such as wastewater treatment, biorefineries, and diagnostics. The knowledge will pave the way toward creating consistent eco-friendly, economically viable nanostructured-based technologies with broad applicability and exploitation for industrial use in the near future.

SARS-CoV-2 transgressing LncRNAs uncovers the known unknowns.

SARS-CoV-2 harbors many known unknown regions in the form of hypothetical open reading frames (ORFs). Although the mechanisms underlying the disease pathogenesis are not clearly understood, molecules such as long noncoding RNAs (lncRNAs) play a key regulatory role in the viral pathogenesis from endocytosis. We asked whether or not the lncRNAs in the host are associated with the viral proteins and argue that lncRNA-mRNAs molecules related to viral infection may regulate SARS-CoV-2 pathogenesis. Toward the end of the perspective, we provide challenges and insights into investigating these transgression pathways.

Cellulolytic, amylolytic and xylanolytic potential of thermophilic isolates of Surajkund hot spring.

A total of 41 isolates were obtained from various samples (soil, mud, and water) of Surajkund hot spring, Jharkhand, at three different isolation temperatures of 50°C, 60°C, and 70°C. However, our interest was in the thermophilic strains that were isolated at 60°C and 70°C. Four isolates at 70°C (BITSNS038, BITSNS039, BITSNS040, BITSNS041) are the producers of thermozymes, namely amylase, xylanase, and cellulase, respectively. The highlights of the present study also showed that three out of four isolates demonstrated all three enzymatic activities, i.e. amylolytic, xylanolytic and cellulolytic on agar plate assay conditions at 70°C. One of the isolates, BITSNS038, was further chosen for phenotypic characterization as well as 16S rRNA gene sequencing and was affiliated to Geobacillus icigianus. The presence of Geobacillus icigianus was reported first time from hot spring, Surajkund, which showed amylolytic index of 1.58, xylanolytic index of 1.5 and cellulolytic index of 2.3 based on plate assay, and amylase activity of 0.81 U/mL, xylanase activity of 0.72 U/mL and very less cellulase activity of 0.15 U/mL after 24 h of growth in submerged conditions. One isolate at 60°C BITSNS024 was found to exhibit maximum amylase activity with an enzymatic index value of 3.5 and was identified as Anoxybacillus gonensis.

Enhanced Tribological and Bacterial Resistance of Carbon Nanotube with Ceria- and Silver-Incorporated Hydroxyapatite Biocoating.

Pertaining to real-life applications (by scaling up) of hydroxyapatite (HA)-based materials, herein is a study illustrating the role of carbon nanotube (CNT) reinforcement with ceria (CeO2) and silver (Ag) in HA on titanium alloy (TiAl6V4) substrate, utilizing the plasma-spraying processing technique, is presented. When compared with pure HA coating enhanced hardness (from 2.5 to 5.8 GPa), elastic modulus (from 110 to 171 GPa), and fracture toughness (from 0.7 to 2.2 MPa·m1/2) elicited a reduced wear rate from 55.3 × 10-5 mm³·N-1·m-1 to 2.1 × 10-5 mm³·N-1·m-1 in HA-CNT-CeO2-Ag. Besides, an order of magnitude lower Archard's wear constant and a 41% decreased shear stress by for HA-CNT-CeO2-Ag coating depicted the effect of higher hardness and modulus of a material to control its wear phenomenon. Antibacterial property of 46% (bactericidal) is ascribed to Ag in addition to CNT-CeO2 in HA. Nonetheless, the composite coating also portrayed exaggerated L929 fibroblast cell growth (4.8 times more than HA), which was visualized as flat and elongated cells with multiple filopodial protrusions. Hence, synthesis of a material with enhanced mechanical integrity resulting in tribological resistance and cytocompatible efficacy was achieved, thereupon making HA-CNT-CeO2-Ag a scalable potent material for real-life load-bearing implantable bio-coating.

Antioxidant and antibacterial hydroxyapatite-based biocomposite for orthopedic applications.

Post-implantation, vicinity acquired oxidative stress and bacterial infections lead to apoptosis with eventual bone-resorption and implant failure, respectively. Thus, in order to combat aforementioned complications, present research aims in utilizing antioxidant ceria (CeO2) and antibacterial silver (Ag) reinforced hydroxyapatite (HA) composite with enhanced mechanical and cytocompatible properties. Highly dense (>90%) spark plasma sintered HA-based composites elicits enhanced elastic modulus (121-133 GPa) in comparison to that of HA. The antioxidant activity is quantified using ceria alone, wherein HA-ceria and HA-ceria-Ag pellets exhibits ~36 and 30% antioxidant activity, respectively, accrediting ceria as a scavenger of reactive oxygen species, which was corroborated with the % Ce3+ change quantified by X-ray photoelectron spectroscopy. The HA-Ag pellet shows antibacterial efficacy of ~61% for E. coli and ~53% for S. aureus, while a reduction of ~59% for E. coli and ~50% for S. aureus is observed for HA-ceria-2.5Ag pellet, affirming Ag reinforcement as an established bactericidal agent. The enhanced hydrophobicity on all the HA-based composites affords a high protein adsorption (24 h incubation). Further, elevated hFOB cell count (~6.7 times for HA-ceria-Ag on day 7) with filopodial extensions (60-150 µm) and matrix-like deposition reflect cell-substrate intimacy. Thus, synergistic antioxidant ceria and antibacterial Ag reinforcement with enhanced mechanical integrity can potentially serve as cytocompatible porous bone scaffolds or bioactive coatings on femoral stems.

Structural and Functional Properties of Exopolysaccharide Excreted by a Novel Bacillus anthracis (Strain PFAB2) of Hot Spring Origin.

Exopolysaccharide produced by a unique avirulent Bacillus anthracis strain PFAB2 of hot spring origin has been characterized and its functional properties are investigated which is a first report. Maximum yield of EPS is 7.66 g/l with 2% glucose and 1% peptone as optimum carbon and nitrogen source respectively. The EPS is found to be a homopolymer consisting of only glucose as principle monosaccharide component. Through 1H NMR study, different dextran-like proton peaks are observed. Molecular weight of the EPS resembles low molecular weight bacterial origin polysaccharides. Melting transition of the EPS has started after 276 °C which indicates good thermal stability. The EPS also shows potent antioxidant activity in terms of DPPH and ABTS mediated free radical scavenging property compared to standard ascorbic acid. Emulsifying property of the EPS is also observed and has shown good emulsification of vegetable oils. The polysaccharide forms a thermo resistant gel during the heating phase, with G' higher than G″ indicating excellent shear-thinning behaviour and viscoelastic nature of the EPS.

Bioengineering of Nitrilases Towards Its Use as Green Catalyst: Applications and Perspectives.

Nitrilases are commercial biocatalysts used for the synthesis of plastics, paints, fibers in the chemical industries, pharmaceutical drugs and herbicides for agricultural uses. Nitrilase hydrolyses the nitriles and dinitriles to their corresponding carboxylic acids and ammonia. They have a broad range of substrate specificities as well as enantio-, regio- and chemo-selective properties which make them useful for biotransformation of nitriles to important compounds because of which they are considered as 'Green Catalysts'. Nitriles are widespread in nature and synthesized as a consequence of anthropogenic and biological activities. These are also present in certain plant species and are known to cause environmental pollution. Biotransformation using native organisms as catalysts tends to be insufficient since the enzyme of interest has very low amount in the total cellular protein, rate of reaction is slow along with the instability of enzymes. Therefore, to overcome these limitations, bioengineering offers an alternative approach to alter the properties of enzymes to enhance the applicability and stability. The present review highlights the aspects of producing the recombinant microorganisms and overexpressing the enzyme of interest for the enhanced stability at high temperatures, immobilization techniques, extremes of pH, organic solvents and hydrolysing dintriles to chiral compounds which may enhance the possibilities for creating specific enzymes for biotransformation.

Enzyme Based Biosensors for Detection of Environmental Pollutants--A Review.

Environmental security is one of the major concerns for the safety of living organisms from a number of harmful pollutants in the atmosphere. Different initiatives, legislative actions, as well as scientific and social concerns have been discussed and adopted to control and regulate the threats of environmental pollution, but it still remains a worldwide challenge. Therefore, there is a need for developing certain sensitive, rapid, and selective techniques that can detect and screen the pollutants for effective bioremediation processes. In this perspective, isolated enzymes or biological systems producing enzymes, as whole cells or in immobilized state, can be used as a source for detection, quantification, and degradation or transformation of pollutants to non-polluting compounds to restore the ecological balance. Biosensors are ideal for the detection and measurement of environmental pollution in a reliable, specific, and sensitive way. In this review, the current status of different types of microbial biosensors and mechanisms of detection of various environmental toxicants are discussed.

Extracellular facile biosynthesis, characterization and stability of gold nanoparticles by Bacillus licheniformis.

CONTEXT: The development of a reliable, eco-friendly process for synthesis of gold nanoparticles (AuNPs) has gained impetus in recent years to counter the drawbacks of chemical and physical methods. OBJECTIVE: This study illustrates simple, green synthesis of AuNPs in vitro using cell lysate supernatant (CLS) of non-pathogenic bacteria and to investigate its potential antimicrobial activity. MATERIALS AND METHODS: Gold nanoparticles were synthesized by the reduction of precursor AuCl4- ions using the CLS of Bacillus licheniformis at 37°C upon 24 h of incubation. The nanoparticles were characterized for their morphology, particle size, optical absorption, zeta potential, and stability. Further the antimicrobial activity was assayed using cup-plate method. RESULTS: The process of biosynthesis was extracellular and the gold ions were reduced to stable nanogold of average size 38 nm. However, upon storage of AuNPs for longer duration at room temperature stability was influenced in terms of increase in particle size and decrease in zeta potential with respect to as synthesized nanoparticles. SEM micrographs revealed the spherical shape of AuNPs and EDX analysis confirmed the presence of gold in the sample. Also clear zone of inhibition was observed against Bacilllus subtilis MTCC 8364, Pseudomonas aeruginosa MTCC 7925, and Escherichia coli MTCC 1698 confirming the antimicrobial activity of AuNPs. DISCUSSION: The bioprocess under study was simple and less time consuming as compared to other methods as the need for harvesting AuNPs from within the microbial cells via downstream process will be eliminated. Nanoparticles exhibited good stability even in absence of external stabilizing agents. AuNPs showed good antimicrobial activity against several Gram-negative and Gram-positive pathogenic bacteria. CONCLUSION: The extracellular biosynthesis from CLS may serve as a suitable alternative for large scale synthesis of gold nanoparticles in vitro. The synthesis from lysed bacterial cell strongly suggests that exposure of microbial whole cells to the gold solution for nanoparticle formation is not necessary and that microorganism even in lysed state retained its bioreduction potential. Further the potential of biologically synthesized AuNPs as antimicrobial agents will be of great commercial importance.

Evaluation of various ions and compounds on nitrilase produced from Streptomyces sp.

The nitrilase produced from a new isolate is evaluated for its activity in presence of a number of different ions and compounds at optimal conditions. It was found that the activity of nitrilase increased up to 10-20% in presence of most of the divalent ions at a concentration of 5 mM relative to the control. Silver, mercury, tin, DTT, ascorbic acid and thiourea, respectively, were observed as potential inhibitors of the enzyme catalysis. The investigation on storage stability of whole cells in presence of a number of stabilizers showed that the enzyme is stable (relative activity 50%) for more than 120 days at various temperatures.

Extraction of bulk DNA from Thar Desert soils for optimization of PCR-DGGE based microbial community analysis

A reliable method for characterizing microbial communities on the basis of their differences in the 16S ribosomal RNA (rRNA) gene sequences in the hot arid zone sandy soils has been optimized. A desert plant (Calligonum polygonoides) was chosen to provide the rhizospheric soil samples, collected from three different agro-ecological locations. Total community DNA was efficiently extracted at small-scale level using direct lysis with hot sodium dodecyl sulphate (SDS), glass bead beating and finally subjecting the sandy soil to liquid nitrogen freeze-thaw cycles. To amplify V3 region of bacterial 16S rRNA gene, universal conserved primers were used. Second round polymerase chain reaction (PCR) was attempted to increase product concentration and to minimize the effect of inhibitory substances. To enhance the detection sensitivity of the denaturing gradient gel electrophoresis (DGGE), the effect of change in template DNA concentration was studied. The separation of bands were greatly enhanced in the fingerprints obtained after the second round of PCR representing low abundant species which were not differentiated at single optimized concentration of DNA.

Influence of medium constituents on the biosynthesis of cephalosporin-C

Acremonium chrysogenum NCIM 1069 was used for the biosynthesis of cephalosporin-C (CPC) in batch mode of cultivation. The effect of different medium constituents for better yield of CPC was thoroughly investigated. From the results of the fermentation, it was found that ammonium sulphate as inorganic nitrogen source and methionine at the concentration of 0.4 percent are most suitable for higher yield of antibiotic. The variation in the C/N ratio on the biosynthesis of CPC showed that a C/N ratio of 8.0 is most suitable for maximum production of CPC