A unique way of energy conservation in glutamate fermenting clostridia

Genetic analysis revealed that Rhodobacter capsulatus contains six rnfABCDEG-genes that are responsible for the electron flow in nitrogen fixation (rnf = Rhodobacter nitrogen fixation). Homolgous genes have been detected in Clostridium tetani. In this work, a membrane complex has been purified from the related Clostridium tetanomorphum that catalyses the reduction of NAD + (E°' = −320 mV) with ferredoxin (E°' ≤ −420 mV). The difference in the redox potential of ≥ 100 mV could be useful for additional energy conservation in the fermentation of glutamate to ammonia, CO 2 , acetate, butyrate, and H 2 . The complex consists of six subunits (RnfABCDEG), of which four N-termini (RnfCDEG) could be sequenced. The sequences are 60-80% identical to the deduced sequences of the Rnf-subunits from C. tetani. The rnf operon has been completely sequenced and aligned with the sequences of C. tetani. The complex contains both non-covalently bound flavin as well as covalently bound flavin. The non-covalently bound flavin was identified as FMN and riboflavin in 1:1 stochiometric ratio, each 0.3 mol/mol Rnf complex (180 kDa). The subunits RnfG and RnfD contain covalently bound flavin linked via phosphodiester bond. The iron was determined as 25±1 mol per Rnf complex. Usually, Rnf activity was measured with NADH and ferricyanide at 420 nm. In order to measure NAD + reduction with reduced ferredoxin catalysed by Rnf complex, the ferredoxin was purified from C. tetanomorphum and reduced by Ti(III)citrate at pH 7.0. High Rnf activities were observed in the membrane preparations of Clostridium aminobutyricum, Clostridium pascui and Clostridium propionicum. Thus, additional energy conservation can be explained in these bacteria. However Rnf activity was absent in Eubacterium barkeri, a nicotinate fermenting bacteria. The soluble butyryl-CoA-dehydrogenase/electron transferring flavoprotein (Bcd/Etf) complex was purified from C. pascui as well as from C. tetanomorphum. The N- terminal sequences of the three subunits (αβγ) showed high identities with the deduced sequences of C. tetani. The Bcd/Etf complex purified from C. tetanomorphum was shown to catalyze the endergonic reduction of ferredoxin with NADH coupled to the exergonic reduction of crotonyl-CoA to butyryl-CoA (E°' = -10 mV) with NADH. The12 reduced ferredoxin could be used for H 2 production catalysed by a hydrogenase or probably used for additional energy conservation via Rnf (about 0.3 mol ATP/ mol glutamate). Experiments with [2,4,4- 2 H] glutamate and detection of citramalate-lyase activity showed that C. pascui and C. tetanomorphum ferment glutamate via the methylaspartate pathway

Purification, Characterization and Functional Analysis of a Serine Protease Inhibitor from the Pulps of Cicer arietinum L. (Chick Pea)

Serine proteinase inhibitors (SPIs) are present in high amount in legume seeds where they play an important role in plant defence mechanism against pests. In the present study, a serine protease inhibitor has been identified from the seeds of Cicer arietinum (L.) and characterized for its inhibitory potency against trypsin and chymotrypsin. Ammonium sulphate fractionation was executed as an initial step to purify the inhibitor. The fraction which was obtained from 30-60% relative ammonium sulphate saturation exhibited the maximum trypsin inhibition activity against 0.2% casein using radial diffusion method. The 30–60% fraction was further subjected to ion exchange chromatography using 1 mL HiTrap Q HP column. The peak fractions were analyzed for the enzymatic activity and also characterized on 12% SDS PAGE. The results indicated that the flow through fraction has retained a significant proteolytic inhibition towards trypsin with a relative molecular mass of approximately 12-13 kDa. The kinetic results have demonstrated that the purified inhibitor from Cicer arietinum L. not only inhibited trypsin but also chymotrypsin. The Circular Dichroism spectrum analysis of the purified inhibitor has revealed that the secondary structure content is highly composed of random coils which were supported by the reports of other low molecular weight trypsin inhibitors. To conclude, a low molecular weight serine protease inhibitor possessing both trypsin and chymotrypsin inhibition from the seeds of C. arietinum has been purified, characterized and the results are reported

On Various Porous Scaffold Fabrication Methods

Three-dimensional scaffolds can be fabricated by various methods. These scaffold constructs showed a major impact on various biomedical applications. The bioactive porous scaffolds should have an excellent three-dimensional architecture and interconnected porous structure for cells adhesion and migration to enhance the therapeutic potential. The porosity and interconnected porous structure can be optimized using various scaffold preparation methods. In this mini review, we discussed the advantages and disadvantages of various commonly used scaffold preparation techniques

Whole Animal Automated Platform for Drug Discovery against Multi-Drug Resistant Staphylococcus aureus

Staphylococcus aureus, the leading cause of hospital-acquired infections in the United States, is also pathogenic to the model nematode Caenorhabditis elegans. The C. elegans-S. aureus infection model was previously carried out on solid agar plates where the bacteriovorous C. elegans feeds on a lawn of S. aureus. However, agar-based assays are not amenable to large scale screens for antibacterial compounds. We have developed a high throughput liquid screening assay that uses robotic instrumentation to dispense a precise amount of methicillin resistant S. aureus (MRSA) and worms in 384-well assay plates, followed by automated microscopy and image analysis. In validation of the liquid assay, an MRSA cell wall defective mutant, MW2ΔtarO, which is attenuated for killing in the agar-based assay, was found to be less virulent in the liquid assay. This robust assay with a Z’-factor consistently greater than 0.5 was utilized to screen the Biomol 4 compound library consisting of 640 small molecules with well characterized bioactivities. As proof of principle, 27 of the 30 clinically used antibiotics present in the library conferred increased C. elegans survival and were identified as hits in the screen. Surprisingly, the antihelminthic drug closantel was also identified as a hit in the screen. In further studies, we confirmed the anti-staphylococcal activity of closantel against vancomycin-resistant S. aureus isolates and other Gram-positive bacteria. The liquid C. elegans – S. aureus assay described here allows screening for anti-staphylococcal compounds that are not toxic to the host

A unique way of energy conservation in glutamate fermenting clostridia

Genetic analysis revealed that Rhodobacter capsulatus contains six rnfABCDEG-genes that are responsible for the electron flow in nitrogen fixation (rnf = Rhodobacter nitrogen fixation). Homolgous genes have been detected in Clostridium tetani. In this work, a membrane complex has been purified from the related Clostridium tetanomorphum that catalyses the reduction of NAD + (E°' = −320 mV) with ferredoxin (E°' ≤ −420 mV). The difference in the redox potential of ≥ 100 mV could be useful for additional energy conservation in the fermentation of glutamate to ammonia, CO 2 , acetate, butyrate, and H 2 . The complex consists of six subunits (RnfABCDEG), of which four N-termini (RnfCDEG) could be sequenced. The sequences are 60-80% identical to the deduced sequences of the Rnf-subunits from C. tetani. The rnf operon has been completely sequenced and aligned with the sequences of C. tetani. The complex contains both non-covalently bound flavin as well as covalently bound flavin. The non-covalently bound flavin was identified as FMN and riboflavin in 1:1 stochiometric ratio, each 0.3 mol/mol Rnf complex (180 kDa). The subunits RnfG and RnfD contain covalently bound flavin linked via phosphodiester bond. The iron was determined as 25±1 mol per Rnf complex. Usually, Rnf activity was measured with NADH and ferricyanide at 420 nm. In order to measure NAD + reduction with reduced ferredoxin catalysed by Rnf complex, the ferredoxin was purified from C. tetanomorphum and reduced by Ti(III)citrate at pH 7.0. High Rnf activities were observed in the membrane preparations of Clostridium aminobutyricum, Clostridium pascui and Clostridium propionicum. Thus, additional energy conservation can be explained in these bacteria. However Rnf activity was absent in Eubacterium barkeri, a nicotinate fermenting bacteria. The soluble butyryl-CoA-dehydrogenase/electron transferring flavoprotein (Bcd/Etf) complex was purified from C. pascui as well as from C. tetanomorphum. The N- terminal sequences of the three subunits (αβγ) showed high identities with the deduced sequences of C. tetani. The Bcd/Etf complex purified from C. tetanomorphum was shown to catalyze the endergonic reduction of ferredoxin with NADH coupled to the exergonic reduction of crotonyl-CoA to butyryl-CoA (E°' = -10 mV) with NADH. The12 reduced ferredoxin could be used for H 2 production catalysed by a hydrogenase or probably used for additional energy conservation via Rnf (about 0.3 mol ATP/ mol glutamate). Experiments with [2,4,4- 2 H] glutamate and detection of citramalate-lyase activity showed that C. pascui and C. tetanomorphum ferment glutamate via the methylaspartate pathway

Influence of Organic Seaweed Pelleting on Seed Quality Parameters of Onion Seeds

Aim: Small and irregular seed shapes make precision sowing difficult. Seed pelleting, which helps to make seed handling easier during sowing, is converting such seeds into bold, spherical shapes with a smooth surface. Seaweeds are a rich source of nutrients that promote growth, such as IAA, kinetin, zeatin, and gibberellins; auxins and cytokinins; metabolic enhancers; macro and micro elements; amino acids; and vitamins. Their use in crop plants has been shown to have positive effects, including early seed germination and establishment, improved crop performance and yield, increased resistance to biotic and abiotic stress, and increased seed shelf life (Bluden). Study Design: The experiment was undertaken with three replications in a completely randomized block design. Eight treatmental combinations were used in this study. Statistical analysis was carried out by AGRES software. The Critical Differences (CD) was calculated at 5 per cent probability level. Place and Duration of Study: Department of Seed Science and Technology, Agriculture College and Research Institute, TNAU, Madurai, during the period of December 2020 and November 2021. Methodology: Organic seaweed pellet combinations can be successfully implemented to provide improved field emergence, crop establishment and production. Seeds were pelleted with different mixtures of Sargassum sp., Kappaphycus sp., Bacillus subtilis and Talc powder. Results: The results exposed that between the treatments seed pelleting with combination of T7- Sargassum sp + Kappaphycus sp + Bacillus subtilis+ Talc powder was found to be more efficient in comparison with other combinations. Conclusion: Pelleting with, Kappaphycus sp, Bacillus subtilis and Talc powder was found to be better in all aspects of seed quality and biochemical parameters

An Intelligent System for Fingerprint Recognition and Verification Using Dilated Convolutional Neural Network and Extreme Learning Machine

Several applications currently utilize fingerprint-based user recognition and authentication, but obtaining complete accuracy (eliminating false matches) is still challenging. Prior to feature extraction, improper image alignment was one of the causes of this problem. This paper proposes a novel fingerprint recognition and verification system using a dilated convolutional neural network (DICNN) and a weighted and bias-optimized extreme learning machine (WBELM). Image preprocessing, feature extraction, and fingerprint recognition are the main phases of the proposed work. To begin, image preprocessing is performed using bilateral filtering to suppress the noise in the gathered images. After that, the proposed system uses DICNN to extract features from the preprocessed images. From the extracted features, fingerprint recognition is done using WBELM. This study conducted experiments on the publicly available FVC 2004 dataset. The proposed model achieves 98.54 percent recognition accuracy with an elapsed time of 584 ms

Suicidal Ideation Detection from social media: A Detailed Review of Machine Learning and Deep Learning

Social networks are crucial tools for learning about people's attitudes towards various issues since they allow them to express their thoughts to friends and family. Recent years have seen considerable challenges in natural language processing (NLP) and psychology regarding the detection of suicidal ideation via online social network analysis. The complex early signs of suicide ideations can be identified with the proper use of social media information, which can afterwards save many lives. Even though numerous strategies have been used over the past few decades to identify suicidal thoughts, machine learning (ML) and deep learning (DL) methods offer more insightful results. So, in this study, we examine several cutting-edge ML and DL approaches for detecting suicidal ideation. We also observe a few significant issues in the entire corpus of literature that could be explored in further research. Finally, we hope this study will shed light on critical issues in identifying suicidal thoughts on social media for readers and ML and DL researchers

Phytochemical Screening and Antimicrobial Activity of Phyllanthus niruri

phyllanthus niruri is an Indian herb used for various ailments by traditional healers. In this study carried out phytochemical analysis and antimicrobial investigation of methanolic extract of the leaves phyllanthus niruri against a panel of clinically significant bacterial and fungal strains. Phytochemical studies revealed the presence of Phenolic compounds, Saponins, Flavonoids, Terpenoids, Alkaloids, Tannins, Cardioglycosides, Steroids, Reducing Sugars, Anthraquinones and Resins. Susceptibility testing by disc diffusion assay revealed significant antimicrobial activity of methanol extract of leaves against Coney lunata and Salmonella typhi. The leaf extract exhibited better antimicrobial activity. The study findings provide supportive evidence for the use of phyllanthus niruri in traditional medicines