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We find out the antimicrobial potential of partially purified 2,4-diacetylphloroglucinol (DAPG) against Ralstonia solanacearum and fungal plant pathogens isolated from tomato rhizobacterium Pseudomonas fluorescens VSMKU3054. The present study is mainly focused on the control of wilt disease of tomato by our isolate VSMKU3054 and DAPG. The cell free culture filtrate of P. fluorescens VSMKU3054 was significantly arrested the growth of R. solanacearum and fungal pathogens such as Rhizoctonia solani, Sclerotium rolfsii, Macrophomina phaseolina and Fusarium oxysporum compared to control. The existence of DAPG from the crude metabolites of P. fluorescens VSMKU3054 was confirmed on TLC with Rf value 0.34, which is coincide with that of authentic phloroglucinol. The partially purified DAPG exhibited much higher activity against R. solanacearum at 30 µg/ml than the fungal plant pathogens compared to control. The antimicrobial partially purified compound was identified as DAPG by UV, FT-IR and GC–MS analysis. The percentage of live cells of R. solanacearum when supplemented with DAPG at 30 µg/ml, significantly controlled the living nature of R. solanacearum up to 68% compared to tetracycline and universal control observed under high content screening analysis. The selected isolate P. fluorescens VSMKU3054 and DAPG significantly controlled wilt disease of tomato up to 59.5% and 42.12% on 3rd and 7th days compared to positive and negative control by detached leaf assay. Further, in silico analysis revealed that high interaction of DAPG encoding protease with lectin which is associated with R. solanacearum. Based on our findings, we confirmed that P. fluorescens VSMKU3054 and DAPG could be used a potential bio inoculants for the management of bacterial wilt disease of tomato.

The high thermoelectric performance of dopant-free, low-cost and eco-friendly p-type Zn1−xSb (x = 0, 0.01, 0.03, and 0.06) is demonstrated by synergistically optimizing its electrical and thermal properties via Zn-vacancy engineering. Upon increasing Zn-vacancies in ZnSb, the bandgap is observed to reduce due to the formation of the impurity states above the valence band, which is theoretically validated using density functional theory (DFT). Remarkably, Zn vacancy-driven point defects significantly influence the hole concentration within the Zn1−xSb samples. At 300 K, the hole concentration (nH) is boosted from 3.6 × 1018 cm−3 (in ZnSb) to 3.4 × 1019 cm−3 for the Zn0.94Sb sample, culminating in a marked enhancement in electrical conductivity (σ) from 1.80 × 104 S m−1 to 7.57 × 104 S m−1 for Zn0.94Sb. Equally noteworthy is the substantial decrease in thermal conductivity (κ) observed in the Zn0.94Sb sample at 673 K, plunging from 2.29 W m−1 K−1 (in ZnSb) to 1.41 W m−1 K−1. This decline in thermal conductivity is attributed to the effective phonon scattering arising from Zn-vacancy-assisted point defects, combined with the efficient coupling of optical and acoustic phonons and the characteristic low group velocity, evidenced by the theoretically calculated phonon dispersion curve. Overall, the high thermoelectric figure of merit, zT of ∼0.8 at 673 K, is achieved for the sample with a 6 mol% Zn deficiency. Furthermore, a maximum theoretical conversion efficiency of ∼7% is predicted at a temperature gradient of 625 K, showing high potential for use in practical devices for mid-temperature applications, and the present work features the effect of a reliable dopant-free approach in improving the overall zT of eco-friendly and low-cost ZnSb. [ABSTRACT FROM AUTHOR]

Microbial bio-products are becoming an appealing and viable alternative to chemical pesticides for effective management of crop diseases. These bio-products are known to have potential to minimize agrochemical applications without losing crop yield and also restore soil fertility and productivity. In this study, the inhibitory efficacy of 2,4-diacetylphloroglucinol (DAPG) produced by Pseudomonas fluorescens VSMKU3054 against Ralstonia solanacearum was assessed. Biochemical and functional characterization study revealed that P. fluorescens produced hydrogen cyanide (HCN), siderophore, indole acetic acid (IAA) and hydrolytic enzymes such as amylase, protease, cellulase and chitinase, and had the ability to solubilize phosphate. The presence of the key antimicrobial encoding gene in the biosynthesis of 2,4-diacetylphloroglucinol (DAPG) was identified by PCR. The maximum growth and antimicrobial activity of P. fluorescens was observed in king’s B medium at pH 7, 37 °C and 36 h of growth. Glucose and tryptone were found to be the most suitable carbon and nitrogen sources, respectively. DAPG was separated by silica column chromatography and identified by various methods such as UV-Vis, FT-IR, GC-MS and NMR spectroscopy. When R. solanacearum cells were exposed to DAPG at 90 µg/mL, the cell viability was decreased, reactive oxygen species (ROS) were increased and chromosomal DNA was damaged. Application of P. fluorescens and DAPG significantly reduced the bacterial wilt incidence. In addition, P. fluorescens was also found effective in promoting the growth of tomato seedlings. It is concluded that the indigenous isolate P. fluorescens VSMKU3054 could be used as a suitable biocontrol agent against bacterial wilt disease of tomato.

A total of 87 FPs have been isolated from tomato (Lycopersicon esculentum) rhizosphere and evaluated by dual plate assay method for the antimicrobial activity of Ralstonia solanacearum. Of which, 30 FPs showed antagonistic activity against R. solanacearum with the zone of inhibitions (ZOI) ranging from 19 mm to 28 mm. Similarly, antagonistic FPs significantly controlled various fungal phytopathogens such as Rhizoctonia solani (6.3 mm−20 mm), Macrophomina phaseolina (8.7 mm−19.3 mm), Fusarium oxysporum (7.3 mm−30.7 mm), and Sclerotium rolfsii (5.3 mm−21 mm). The cell-free culture filtrate of Pseudomonas sp VSMKU3054 significantly suppressed the fungal pathogens and increased the root and shoot length of the tomato seedlings compared to the control. Furthermore, the antagonistic FPs effectively produced lytic enzymes and antimicrobial traits such as amylase (6), protease (30), cellulase (28), pectinase (12), chitinase (22), gelatinase (27), siderophore (28), hydrogen cyanide (25), phosphate solubilization (30), and Indole acetic acid (IAA) (23). Genetic diversity of FPs was assessed by BOX-PCR with specific primers revealed that two distinct clusters were observed, whereas, RFLP analyses were showed that 5 to 16 bands ranged from 75 bp to 1.2 bp with two major clusters using restriction enzyme HaeIII. The antibiotic encoding genes were detected from FPs, of which 10 FPs were positive for 2,4-diacetylphloroglucinol (DAPG), 9 FPs were positive for pyoleuterin (PLT), 10 FPs were positive for hydrogen cyanide (HCN) and none of them obtained pyrrolnitrin (PRN) with respective primers. Based on the superior antagonistic isolates against R. solanacearum and phytofungal pathogens and other antimicrobial traits, the isolate VSMKU3054 was selected for further studies. Based on the morphological, physiological and 98% of 16 s rDNA sequence similarity, the selected isolate VSMKU3054 was identified as Pseudomonas fluorescens. Further, the potential isolate P. fluorescens VSMKU3054 and cell free culture filtrate remarkably enhance tomato seedling growth such as root and shoot length, fresh and dry weight and vigor index compared to control. This study indicated that rhizospheric isolates of FPs have more potential for plant growth promotion and plant protection from plant pathogenic microbes.

Background and aim: Cricket is the most commonly played and followed sport in India and demands a high level of performance from the fast bowler. Large ground reaction forces generated at front foot contact put fast bowlers at high risk of lower limb and lumbar spine injury. Precise dynamic coordination of lower body segments is needed to absorb these forces and transfer the energy via the core to the upper limb to propel the ball at faster speeds. Thus, knowledge of lower quadrant strength, especially dynamic knee strength, can be useful for injury prevention and better performance in fast bowlers. There is a lack of literature on this subject in Indian fast bowlers despite the popularity of the sport. This study aims to evaluate isokinetic knee strength and determine the relevant asymmetries and strength imbalances in relation to injury risk in cricket fast bowlers. Methods: A total of 42 male Indian state-level fast bowlers underwent isokinetic knee strength testing. Peak torques (PT) normalized to body weight (BW) were obtained for quadriceps concentric (Qconc), quadriceps eccentric (Qecc), hamstring concentric (Hconc), and hamstring eccentric (Hecc). Bilateral strength asymmetries (BSA) and dynamic control ratio (DCR) (hamstring DCR (H-DCR) = Hecc/Qconc and quadriceps DCR (Q-DCR) = Qecc/Hconc) were evaluated. Descriptive statistical analysis of data was done. Results: Around 67% of bowlers had significant Qecc strength asymmetry. In addition, 40% had poor hamstrings DCR and 19% had poor Q-DCR on the front limb. Conclusion: A significant proportion of fast bowlers have unfavorable strength asymmetry and DCR and could be at risk of injury. Improving dynamic knee strength through plyometric training could help optimize performance and reduce injury risk. Clinical significance: This study highlights key areas of possible injury risk that can be targeted with strength and conditioning to prevent lower limb and lumbar spine injuries in fast bowlers. [ABSTRACT FROM AUTHOR]

The continuous depletion of fossil fuels and the increasing demand for eco-friendly and sustainable energy sources have prompted researchers to look for alternative energy sources. The loss of thermal energy in heat engines (100 °C–350 °C), coal-based thermal plants (150 °C–700 °C), heated water pumping in the geothermal process (150 °C–700 °C), and burning of petrol in the automobiles (150 °C–250 °C) in form of untapped waste-heat can be directly and/or reversibly converted into usable electricity by means of charge carriers (electrons or holes) as moving fluids using thermoelectric (TE) technology, which works based on typical Seebeck effect. The enhancement in TE conversion efficiency has been a key challenge because of the coupled relation between thermal and electrical transport of charge carriers in a given material. In this review, we have deliberated the physical concepts governing the materials to device performance as well as key challenges for enhancing the TE performance. Moreover, the role of crystal structure in the form of chemical bonding, crystal symmetry, order–disorder and phase transition on charge carrier transport in the material has been explored. Further, this review has also emphasized some insights on various approaches employed recently to improve the TE performance, such as, (i) carrier engineering via band engineering, low dimensional effects, and energy filtering effects and (ii) phonon engineering via doping/alloying, nano-structuring, embedding secondary phases in the matrix and microstructural engineering. We have also briefed the importance of magnetic elements on thermoelectric properties of the selected materials and spin Seebeck effect. Furthermore, the design and fabrication of TE modules and their major challenges are also discussed. As, thermoelectric figure of merit, zT does not have any theoretical limitation, an ideal high performance thermoelectric device should consist of low-cost, eco-friendly, efficient, n - or p -type materials that operate at wide-temperature range and similar coefficients of thermal expansion, suitable contact materials, less electrical/thermal losses and constant source of thermal energy. Overall, this review provides the recent physical concepts adopted and fabrication procedures of TE materials and device so as to improve the fundamental understanding and to develop a promising TE device. [ABSTRACT FROM AUTHOR]