Fixation Ability Research Articles

Combined dynamic transcriptome and flavonoid metabolome reveal the role of Mo nanoparticles in the nodulation process in soybean

Symbiotic nitrogen fixation can reduce the impact of agriculture on the environment by reducing fertilizer input. The rapid development of nanomaterials in agriculture provides a new prospect for us to improve the biological nitrogen fixation ability of leguminous crops. Molybdenum is an important component of nitrogenase, and the potential application of MoO3NPs in agriculture is largely unexplored. In this study, on the basis of verifying that MoO3NPs can improve the nitrogen fixation ability of soybean, the effects of MoO3NPs on the symbiotic nitrogen fixation process of soybean were investigated by using dynamic transcriptome and targeted metabolome techniques. Here we showed that compared with conventional molybdenum fertilizer, minute concentrations of MoO3NPs (0.01–0.1 mg kg−1) could promote soybean growth and nitrogen fixation efficiency. The nodules number, fresh nodule weight and nitrogenase activity of 0.1 mg kg−1 were increased by 17 %, 14 % and 27 %, and plant nitrogen accumulation increased by 17 %. Compared with conventional molybdenum fertilizer, MoO3NPs had a greater effect on apigenin, kaempferol and other flavonoid, and the expression of nodulation related genes such as ENOD93, F3'H. Based on WGCNA analysis, we identified a core gene GmCHS9 that was positively responsive to molybdenum and was highly expressed during MoO3NPs induced nodulation. MoO3NPs could improve the nitrogen fixation ability of soybean by promoting the secretion of flavonoids and the expression of key genes. This study provided a new perspective for the nano-strengthening strategy of nodules development and flavonoid biosynthesis by molybdenum.

Nitrogen fixation of different seasons and parts of seagrass Enhalus acoroides in Xincun Bay, northern South China Sea

In coastal ecosystems, the nitrogen fixation of seagrasses is crucial. However, the nitrogen fixation rates of seagrasses can vary spatially and temporally, especially in tropical regions. To investigate the nitrogen fixation rates of Enhalus acoroides, we used principal component analysis to examine the rates of nitrogen fixation in the roots, rhizome, and leaves of E. acoroides during the southwest monsoon (July) and the northeast season (October and January), respectively. The results showed that the nitrogen fixation rates in all three parts of E. acoroides were significantly higher during the southwest monsoon period compared to the northeast period. The rates of nitrogen fixation in the leaves of E. acoroides were found to be higher than in the roots and rhizomes. The difference in nitrogen fixation between the various parts of E. acoroides was highly significant (p<0.01). The nitrogen fixation activity of E. acoroides was significantly affected by temperature, as determined by principal component analysis. The spatial variations observed in different regions of E. acoroides were influenced by environmental factors in addition to the temperature-driven seasonal changes. The results suggest that temperature plays a vital role in the nitrogen fixation ability of E. acoroides.

Exploration of nyamplung rizosphere nitrogen fixing bacteria in mine reclamation

Nitrogen fixing bacteria have the ability to utilize free nitrogen as a nitrogen source for their growth. These bacteria are able to make efficient availability of N- in the soil, so that it can be utilized by plants. The aim of this study was to obtain nitrogen fixing bacteria isolates from the rhizosphere of nyamplung plants in limestone reclamation lands. Isolation and testing of nitrogen fixation ability by nitrogen fixing bacteria was carried out using selective Ashby's Mannitol Agar media. The isolation results obtained 5 isolates on Ashby's Mannitol Agar media. The morphological characters of the colonies of the five isolates showed round and irregular shapes, flat and convex elevations with flat edges, white, cloudy white and clear. Microscopic observation showed that the isolates consisted of gram-positive and negative bacteria with bacilli cell shape. The catalase test showed 4 positive isolates and 1 negative. The conclusion of this study was that 5 nitrogen fixing bacteria isolates were obtained from the rhizosphere of the nyamplung limestone land plant. Isolates 1, 3, and 5 showed the character of the genus Clostridium, isolate 2 led to the genus Bacillus, and isolate 4 had the same character as the genus Klabsiella.

In situ constructing of sulfur bedecked ZIF-67 with ultrahigh and selectivity UO22+ immobilization capability from seawater

Uranium, a strategically significant resource, is estimated to contain approximately 4.5 billion tons of unconventional uranium in seawater, which can be extracted as a sustainable fuel source for nuclear power plants. In this work, a sulfur bedecked ZIF-67 (SF@ZIF-67) uranium adsorbent were successfully fabricated by employing a facile hydrothermal sulfur functionalization approach. Sequential batch experiment showed that the SF@ZIF-67 specimen displayed a broader pH response range, exceptional UO22+ harvesting efficiency (Uinitial = ∼5–10 ppm, ∼90.68 %–93.79 %) and ultra-high uranium capture capacity (qmax = 769.23 mg/g). Remarkably, due to the strong affinity between sulfur functional groups and uranyl, the SF@ZIF-67 sample exhibited exceptional selectivity with a Kd value exceeding 104 mL/g even in the presence of diverse interfering ions. Moreover, the SF@ZIF-67 specimen showed a sustained uptake efficiency of 66.61 % with close 104 KdU value in a 3000-fold VO43− system. In natural uranium spiked-seawater (Uinitial = ∼10–1000 μg/L), SF@ZIF-67 can capture ∼21–2484.5 μg/g uranium after 24 h contact. Mechanism analysis confirmed that excellent uranyl fixation ability is attributed to the coordination of sulfur and oxygen terminals with uranyl, as well as the redox processes of S2− and U6+. This hydrothermal functionalization technique offers novel insights into the potential application of MOF materials for uranium extraction from seawater.

Biochar as a highly efficient adsorption carrier for sewage sludge-derived nutrients and biostimulants: component fixation and mechanism

Production of liquid fertilizers containing nitrogenous nutrients and biostimulants from sewage sludge (SS-NB) has been attracting increasing attention due to its excellent fertilization effect and resource recycling attributes. To better understand the functional effects of nutrients and biostimulants in SS-NB on soil, the adsorption capacity and mechanism of straw biochar (SB) and wood chip biochar (WCB) for alkaline and neutral SS-NB components were investigated. The adsorption of total organic carbon (TOC) from alkaline and neutral SS-NB by WCB was 61.14% and 89.73%, respectively, higher than that by SB, which was 56.25% and 83.36%. Moreover, TOC from neutral SS-NB was more readily adsorbed, especially for fulvic and humic acids. SB had a strong adsorption capacity for calcium ions and nitrogen (TKN, nitrate N, protein, amino acid) and released large amounts of P. In addition, WCB and SB showed a strong affinity for macromolecules (proteins) and reducing substances (lignin and lipids) and excellent fixation ability for phytohormones and allelochemicals. However, WCB adsorbed more types of molecular substances than SB while maintaining a high immobilization rate. Analysis of the adsorption mechanism showed that surface amino groups of the biochar were involved in adsorption, while WCB had additionally high adsorption efficiencies through pore adsorption, hydrogen bonding adsorption and pore size-exclusion effects. The study revealed that biochar can be used as an efficient adsorption carrier for SS-NB to improve soil fertility management.Graphical

Design of Bionic Foot Inspired by the Anti-Slip Cushioning Mechanism of Yak Feet.

In recent years, legged robots have been more and more widely used on non-structured terrain, and their foot structure has an important impact on the robot's motion performance and stability. The structural characteristics of the yak foot sole with a high outer edge and low middle, which has excellent soil fixation ability and is an excellent bionic prototype, can improve the friction between the foot and the ground. At the same time, the foot hooves can effectively alleviate the larger impact load when contacting with the ground, which is an excellent anti-slip buffer mechanism. The bionic foot end design was carried out based on the morphology of the yak sole; the bionic foot design was carried out based on the biological anatomy observation of yak foot skeletal muscles. The virtual models of the bionic foot end and the bionic foot were established and simulated using Solidworks 2022 and Abaqus 2023, and the anti-slip performance on different ground surfaces and the influence of each parameter of the bionic foot on the cushioning effect were investigated. The results show that (1) the curved shape of the yak sole has a good anti-slip performance on both soil ground and rocky ground, and the anti-slip performance is better on soil ground; (2) the curved shape of the yak sole has a larger maximum static friction than the traditional foot, and the anti-slip performance is stronger under the same pressure conditions; (3) the finger pillow-hoof ball structure of the bionic foot has the greatest influence on the buffering effect, and the buffering effect of the bionic foot is best when the tip of the bionic foot touches the ground first.

Nitrospirillum viridazoti sp. nov., an Efficient Nitrogen-Fixing Species Isolated from Grasses.

A group of Gram-negative plant-associated diazotrophic bacteria belonging to the genus Nitrospirillum was investigated, including both previously characterized and newly isolated strains from diverse regions and biomes, predominantly in Brazil. Phylogenetic analysis of 16S rRNAand recA genes revealed the formation of a distinct clade consisting of thirteen strains, separate from the formally recognized species N. amazonense (the closest species) and N. iridis. Comprehensive taxonomic analyses using the whole genomes of four strains (BR 11140T = AM 18T = Y-2T = DSM 2788T = ATCC 35120T, BR 11142T = AM 14T = Y-1T = DSM 2787T = ATCC 35119T, BR 11145 = CBAmC, and BR 12005) supported the division of these strains into two species: N. amazonense (BR 11142T and BR 12005) and a newly proposed species (BR 11140T and BR 11145), distinct from N. iridis. The phylogenomic analysis further confirmed the presence of the new Nitrospirillum species. Additionally, MALDI-TOF MS analysis of whole-cell mass spectra provided further evidence for the differentiation of the proposed Nitrospirillum species, separate from N.amazonense. Analysis of chemotaxonomy markers (i.e., genes involved in fatty acid synthesis, metabolism and elongation, phospholipid synthesis, and quinone synthesis) revealed that the new species highlights high similarity and evolutionary convergence with other Nitrospirillum species. This new species exhibited nitrogen fixation ability in vitro, it has similar NifHDK protein phylogeny position with the closest species, lacked denitrification capability, but possessed the nosZ gene, enabling N2O reduction, distinguishing it from the closest species. Despite being isolated from diverse geographic regions, soil types, and ecological niches, no significant phenotypic or physiological differences were observed between the proposed new species and N. amazonense. Based on these findings, a new species, Nitrospirillum viridazoti sp. nov., was classified, with the strain BR 11140T (DSM 2788T, ATCC 35120T) designated as the type strain.

Comparison of the clinical outcomes between proximal femoral nail anti-rotation with cement enhancement and hemiarthroplasty among elderly osteoporotic patients with intertrochanteric fracture

BackgroundThe proximal femoral nail anti-rotation (PFNA) with cement enhancement enhances the anchorage ability of internal fixation in elderly with osteoporotic intertrochanteric fracture. However, whether it is superior to hemiarthroplasty is still controversial. The present study aimed to determine which treatment has better clinical outcomes among older patients.MethodsWe retrospectively analyzed 102 elderly patients with osteoporosis who developed intertrochanteric fractures and underwent PFNA combined with cement-enhanced internal fixation (n = 52, CE group), and hemiarthroplasty (n = 50, HA group) from September 2012 to October 2018. All the intertrochanteric fractures were classified according to the AO/OTA classification. Additionally, the operative time, intraoperative blood loss, intraoperative and postoperative blood transfusion rates, postoperative weight-bearing time, hospitalization time, Barthel Index of Activities Daily Living, Harris score of hip function, visual analog (VAS) pain score, and postoperative complications were compared between the two groups.ResultsThe CE group had significantly shorter operative time, lesser intraoperative blood loss, lower blood transfusion rate, and longer postoperative weight-bearing time than the HA group. The CE group had lower Barthel’s Index of Activities of Daily Living, lower Harris’ score, and higher VAS scores in the first and third months after surgery than the HA group, but no difference was observed between the two groups from 6 months to 12 months. There was no significant difference in the total post-operative complications between the two groups.ConclusionThe use of PFNA combined with a cement-enhanced internal fixation technique led to shorter operative time and lesser intraoperative blood loss and trauma in elderly patients as compared to HA.

Synergistic Effect of CO2 in Accelerating the Galvanic Corrosion of Lithium/Sodium Anodes in Alkali Metal-Carbon Dioxide Batteries.

Rechargeable alkali metal-CO2 batteries, which combine high theoretical energy density and environmentally friendly CO2 fixation ability, have attracted worldwide attention. Unfortunately, their electrochemical performances are usually inferior for practical applications. Aiming to reveal the underlying causes, a combinatorial usage of advanced nondestructive and postmortem characterization tools is used to intensively study the failure mechanisms of Li/Na-CO2 batteries. It is found that a porous interphase layer is formed between the separator and the Li/Na anode during the overvoltage rising and battery performance decaying process. A series of control experiments are designed to identify the underlying mechanisms dictating the observed morphological evolution of Li/Na anodes, and it is found that the CO2 synergist facilitates Li/Na chemical corrosion, the process of which is further promoted by the unwanted galvanic corrosion and the electrochemical cycling conditions. A detailed compositional analysis reveals that the as-formed interphase layers under different conditions are similar in species, with the main differences being their inconsistent quantity. Theoretical calculation results not only suggest an inherent intermolecular affinity between the CO2 and the electrolyte solvent but also provide the most thermodynamically favored CO2 reaction pathways. Based on these results, important implications for the further development of rechargeable alkali metal-CO2 batteries are discussed. The current discoveries not only fundamentally enrich our knowledge of the failure mechanisms of rechargeable alkali metal-CO2 batteries but also provide mechanistic directions for protecting metal anodes to build high-reversible alkali metal-CO2 batteries.

Microbial inoculation alters rhizoplane bacterial community and correlates with increased rice yield

Microbial inoculants are recognized as environmentally friendly methods to promote plant growth and improve soil properties. However, the effects of inoculation on the rhizosphere and rhizoplane community structure of plants remain poorly documented and need further investigation. Rhodopseudomonas palustris (R. palustris) strain has nitrogen fixing ability and Bacillus subtilis (B. subtilis) strain is a plant growth-promoting rhizobacterium (PGPR). In this study, we investigated the effects of single and co-inoculation with R. palustris and B. subtilis on the increase of rice yield as well as on the microbial communities in the rhizosphere and rhizoplane of rice through potting experiments, respectively. The results showed that inoculation significantly increased rice yield and seed setting rate, with co-inoculation raising the yield by up to 13.7%. Inoculation influenced both rhizosphere and rhizoplane community structures and functions, amplifying the differences between them. The most significant changes were brought about by the combined inoculation treatment. Co-inoculation with R. palustris and B. subtilis had a synergistic effect. The profound alterations of rhizoplane bacterial community structures and functions were proved to be positively correlated with rice yield and seed setting rate (r = 0.59–0.76, p < 0.05). These results provide new ideas for the investigation of the potential microbiological mechanisms of microbial co-inoculation in practical agricultural applications.

Smart multifaceted potential microbial inoculant isolated from rhizospheric soils of Bergenia ciliata and possible role in developing green biosynthesized nanoparticles

Nanotechnology employs miniscule yet potential nanoparticles and has immense applications in various fields of scientific research. This has revolutionized technological advancements in multiple spheres and recently touched the field of plant biology and sustainable agriculture. Beneficial rhizobacteria isolated from plants may prove efficacious as they are able to impart plant growth. From the medicinal plant Bergenia ciliata, one isolate BC-I-15 was characterized in this study and displayed growth promoting traits. 16s rDNA sequencing and molecular characterization confirmed the isolate as Pseudomonas sp. (NCBI accession number- OQ891764) which showed similarity with other Pseudomonads in phylogenetic tree. The isolate exhibited oxidative stress tolerance assay, nitrogen fixing ability, IAA, calcite and phosphate solubilization etc. But such microbial bioinoculants suffers from few limitations and can be enriched when their nanoparticle counterparts are developed for efficient function. The citation network analysis showed good and encouraging relationships between terms like ‘Nanoparticles, Microbes, Sustainable agriculture’. So, when such beneficial microbes in bulk form, or biofilm and exopolysaccharides (EPS) secreting, secondary metabolites etc. parts thereof are used as starting material for nanoparticle formation, then such nanoparticles possess intrinsic and enriched capacity to impart stress tolerance to plants and impart qualities in sustainable agriculture. The results of the present study, further aids in the efficient utilization of the selected beneficial BC-I-15 rhizobacteria and their future exploration in developing biogenic nanoparticles for active agents in sustainable agriculture.

Two-stage Inhibition Effects of Burkholderia sp. Y4 Application on Cadmium Uptake and Transport in Wheat

In order to evaluate the feasibility of using Burkholderia sp. Y4 as a cadmium （Cd）-reducing bacterial agent in contaminated wheat fields， the changes in the rhizosphere soil microbial community and Cd available state， as well as the content and transport characteristics of Cd in the wheat root， basal node， internode， and grain under the treatment of strain Y4 were tested using microbial high-throughput sequencing， step-by-step extraction， subcellular distribution， and occurrence analyses. The results showed that root application of strain Y4 significantly reduced the root and grain Cd content of wheat by 7.7% and 30.3%， respectively， compared with that in the control treatment. The Cd content and Cd transfer factor results in wheat vegetative organs showed that strain Y4 reduced the Cd transfer factor from basal node to internode by 79.3%， and Cd content in the wheat internode stem also decreased by 50.9%. The study of Cd occurrence morphology showed that strain Y4 treatment increased the proportion of residual Cd in roots and basal ganglia， decreased the contents of inorganic and water-soluble Cd in roots， and increased the content of residual Cd in basal ganglia. Further examination of the subcellular distribution of Cd showed that the Cd content in root cell walls and basal ganglia cell fluid increased by 21.3% and 98.2%， respectively， indicating that the Cd fixation ability of root cell walls and basal ganglia cell fluid was improved by the strain Y4 treatment. In the rhizosphere soil， it was found that the microbial community structure was changed by strain Y4 application. Under the Y4 treatment， the relative abundance of Burkholderia increased from 9.6% to 11.5%， whereas that of Acidobacteriota decreased. Additionally， the relative abundance of Gemmatimonadales， Pseudomonadales， and Chitinophagales were also increased by strain Y4 treatment. At the same time， the application of strain Y4 increased the pH value of rhizosphere soil by 8.3%. The contents of exchangeable Cd， carbonate-bound Cd， and iron-manganese oxide-bound Cd in the soil decreased by 44.4%， 21.7%， and 15.9%， respectively， whereas the proportion of residual Cd reached 53.6%. Root application of strain Y4 increased the contents of nitrate nitrogen and ammonium nitrogen in the soil by 22.0% and 21.4%， respectively， and the contents of alkaline nitrogen also increased to a certain extent. In conclusion， the root application of strain Y4 not only improved soil nitrogen availability but also inhibited Cd transport and accumulation from contaminated soil to wheat grains in a "two-stage" manner by reducing Cd availability in rhizosphere soil and improving Cd interception and fixation capacity of wheat roots and basal nodes. Therefore， Burkholderia Y4 has application potential as a Cd-reducing and growth-promoting agent in wheat.

MOF-Derived CoSe2 Nanoparticles/Carbonized Melamine Foam as Catalytic Cathode Enabling Flexible Li-CO2 Batteries with High Energy Efficiency and Stable Cycling.

Rechargeable aprotic Li-CO2 batteries have aroused worldwide interest owing to their environmentally friendly CO2 fixation ability and ultra-high specific energy density. However, its practical applications are impeded by the sluggish reaction kinetics and discharge product accumulation during cycling. Herein, a flexible composite electrode comprising CoSe2 nanoparticles embedded in 3D carbonized melamine foam (CoSe2/CMF) for Li-CO2 batteries is reported. The abundant CoSe2 clusters can not only facilitate CO2 reduction/evolution kinetics but also serve as Li2CO3 nucleation sites for homogeneous discharge product growth. The CoSe2/CMF-based Li-CO2 battery exhibits a large initial discharge capacity as high as 5.62mAhcm-2 at 0.05mAcm-2, a remarkably small voltage gap of 0.72V, and an ultrahigh energy efficiency of 85.9% at 0.01mAcm-2, surpassing most of the noble metal-based catalysts. Meanwhile, the battery demonstrates excellent cycling stability of 1620h (162 cycles) at 0.02mAcm-2 with an average overpotential of 0.98V and energy efficiency of 85.4%. Theoretical investigations suggest that this outstanding performance is attributed to the suitable CO2/Li adsorption and low Li2CO3 decomposition energy. Moreover, flexible Li-CO2 pouch cell with CoSe2/CMF cathode displays stable power output under different bending deformations, showing promising potential in wearable electronic devices.

Pseudomonas chlororaphis IRHB3 assemblies beneficial microbes and activates JA-mediated resistance to promote nutrient utilization and inhibit pathogen attack.

The rhizosphere microbiome is critical to plant health and resistance. PGPR are well known as plant-beneficial bacteria and generally regulate nutrient utilization as well as plant responses to environmental stimuli. In our previous work, one typical PGPR strain, Pseudomonas chlororaphis IRHB3, isolated from the soybean rhizosphere, had positive impacts on soil-borne disease suppression and growth promotion in the greenhouse, but its biocontrol mechanism and application in the field are not unclear. In the current study, IRHB3 was introduced into field soil, and its effects on the local rhizosphere microbiome, disease resistance, and soybean growth were comprehensively analyzed through high-throughput sequencing and physiological and molecular methods. We found that IRHB3 significantly increased the richness of the bacterial community but not the structure of the soybean rhizosphere. Functional bacteria related to phosphorus solubilization and nitrogen fixation, such as Geobacter, Geomonas, Candidatus Solibacter, Occallatibacter, and Candidatus Koribacter, were recruited in rich abundance by IRHB3 to the soybean rhizosphere as compared to those without IRHB3. In addition, the IRHB3 supplement obviously maintained the homeostasis of the rhizosphere microbiome that was disturbed by F. oxysporum, resulting in a lower disease index of root rot when compared with F. oxysporum. Furthermore, JA-mediated induced resistance was rapidly activated by IRHB3 following PDF1.2 and LOX2 expression, and meanwhile, a set of nodulation genes, GmENOD40b, GmNIN-2b, and GmRIC1, were also considerably induced by IRHB3 to improve nitrogen fixation ability and promote soybean yield, even when plants were infected by F. oxysporum. Thus, IRHB3 tends to synergistically interact with local rhizosphere microbes to promote host growth and induce host resistance in the field.

First Report of Powdery Mildew Caused by Podosphaera xanthii on Phasey Bean (Macroptilium lathyroides) in China.

The forage legume phasey bean Macroptilium lathyroides (L.) Urb. is an annual or short-lived perennial of the family Fabaceae. It is native to the tropical and subtropical areas from North to South America, and is naturalized throughout the tropics and subtropics of the world (Tobisa and Nakano 2019). It is mainly used for forage, green manure, and slope protection (Silva et al. 2018). In addition, the nitrogen fixation ability of this plant can also improve the soil. In February 2022 and January 2023, powdery mildew symptoms were observed on 70% of M. lathyroides plants on the Hainan Medical University campus (19° 58' 53″ N; 110° 19' 47″ E) in Haikou, Hainan Province, China. Powdery mildew colonies covered the leaf surfaces and stems of affected plants, causing discoloration and defoliation. Mycelia were superficial and hyphal appressoria were nipple-shaped. Conidiophores (n =30) were unbranched, cylindrical, 100 to 233 × 8 to 15 µm, and produced three to five immature conidia in chains with a crenate outline. Foot cells (n =30) were cylindrical, straight or sometimes curved at the base, and 36 to 56 µm long. Conidia (n =100) were ellipsoid-ovoid to doliiform, 24 to 34 ×13 to 20 m (length/width ratio = 1.5 to 2.3), with well-developed fibrosin bodies, and produced germ tubes from the lateral position. Based on these morphological characteristics, the pathogen was provisionally identified as Podosphaera xanthii (Braun and Cook 2012). The teleomorph was not observed. A specimen was deposited in the Hainan Medical University Plant Pathology Herbarium as HMML-23. To confirm the identification, genomic DNA was extracted from mycelium, conidiophores, and conidia using a fungal DNA kit (Omega Bio-Tek, USA). The rDNA internal transcribed spacer (ITS) region was amplified with primers ITS1/ITS4 (White et al. 1990) and sequenced directly. The resulting 575-bp sequence was deposited in GenBank (accession no. OR240256). A BLASTn search in GenBank of this sequence showed 100% similarity with the ITS sequences of P. xanthii isolates from China (MT242593, MK439611 and MH143483), Korea (MG754404), Vietnam (KM260704), Japan (MZ604267), and Puerto Rico (OP882310). Additionally, the 28S rDNA region was amplified using the primer pairs NL1 and NL4 (O´Donnell 1993; accession no. OR240255). This region shared 100% similarity with P. xanthii isolates (MK357436, LC371333, OP765401, and MZ604267) as well. To confirm pathogenicity, five healthy potted plants of M. lathyroides were inoculated by gently pressing a powdery mildew-infected leaf onto 15 young leaves. Five non-inoculated plants served as controls. All plants were maintained in a greenhouse at 24 to 30°C, 70% relative humidity, with a 16-h photoperiod. After 7 days, inoculated leaves showed powdery mildew symptoms whereas no symptoms were observed on control plants. The fungal colonies observed on inoculated plants were morphologically identical to those found on the originally infected leaves collected from Hainan Province. Based on the morphological characteristics and molecular identification, the fungus was identified as P. xanthii. This fungus has been reported causing powdery mildew on M. atropurpureum in Thailand (Meeboon et al. 2016). In the United States phasey bean powdery mildew caused by Erysiphe fallax has been previously reported (Poudel and Zhang 2019). To our knowledge, this is the first record of P. xanthii infecting M. lathyroides in China. Over the past 50 years of introduction, phasey bean has become one of the main leguminous forages for establishing artificial mixed seeding grasslands in southern China. We are concerned that the pathogen could become a threat to the widespread planting of M. lathyroides in the future.

Pontiella agarivorans sp. nov., a novel marine anaerobic bacterium capable of degrading macroalgal polysaccharides and fixing nitrogen.

Marine macroalgae produce abundant and diverse polysaccharides, which contribute substantially to the organic matter exported to the deep ocean. Microbial degradation of these polysaccharides plays an important role in the turnover of macroalgal biomass. Various members of the Planctomycetes-Verrucomicrobia-Chlamydia (PVC) superphylum are degraders of polysaccharides in widespread anoxic environments. In this study, we isolated a novel anaerobic bacterial strain NLcol2T from microbial mats on the surface of marine sediments offshore Santa Barbara, CA, USA. Based on 16S ribosomal RNA (rRNA) gene and phylogenomic analyses, strain NLcol2T represents a novel species within the Pontiella genus in the Kiritimatiellota phylum (within the PVC superphylum). Strain NLcol2T is able to utilize various monosaccharides, disaccharides, and macroalgal polysaccharides such as agar and ɩ-carrageenan. A near-complete genome also revealed an extensive metabolic capacity for anaerobic degradation of sulfated polysaccharides, as evidenced by 202 carbohydrate-active enzymes (CAZymes) and 165 sulfatases. Additionally, its ability of nitrogen fixation was confirmed by nitrogenase activity detected during growth on nitrogen-free medium, and the presence of nitrogenases (nifDKH) encoded in the genome. Based on the physiological and genomic analyses, this strain represents a new species of bacteria that may play an important role in the degradation of macroalgal polysaccharides and with relevance to the biogeochemical cycling of carbon, sulfur, and nitrogen in marine environments. Strain NLcol2T (= DSM 113125T = MCCC 1K08672T) is proposed to be the type strain of a novel species in the Pontiella genus, and the name Pontiella agarivorans sp. nov. is proposed.IMPORTANCEGrowth and intentional burial of marine macroalgae is being considered as a carbon dioxide reduction strategy but elicits concerns as to the fate and impacts of this macroalgal carbon in the ocean. Diverse heterotrophic microbial communities in the ocean specialize in these complex polymers such as carrageenan and fucoidan, for example, members of the Kiritimatiellota phylum. However, only four type strains within the phylum have been cultivated and characterized to date, and there is limited knowledge about the metabolic capabilities and functional roles of related organisms in the environment. The new isolate strain NLcol2T expands the known substrate range of this phylum and further reveals the ability to fix nitrogen during anaerobic growth on macroalgal polysaccharides, thereby informing the issue of macroalgal carbon disposal.

A NOVEL 3D-PRINTED DUAL-MOBILITY IMPLANT: RESULTS UP TO SEVEN YEARS IN CLINICAL PRACTICE

Dual mobility (DM) is an established bearing option in Total Hip Arthroplasty (THA). The traditional mono-block DM designs have limited ability for additional fixation, whereas the modular DM designs allow additional screw fixation but limit internal diameter and have the potential to generate metal debris. We report the early results of a CoCrMo alloy mono-block implant manufactured by additive technology with a highly porous ingrowth surface to enhance primary fixation and osseointegration.Prospective follow-up of the DuplexTM implant first inserted in March 2016 enrolled into Beyond Compliance (BC). Primary outcome measure was all-cause revision and secondary outcomes dislocation, peri-prosthetic fracture (PPF) and Oxford Hip Score (OHS). Patients were risk stratified and all considered to be high risk for instability. Complications were identified via hospital records, clinical coding linkage using national database and via BC website.159 implants in 154 patients with a mean age 74.0 years and a maximum F/U of 7 years. Survivorship for all-cause revision 99.4% (95% CI 96.2–99.8). One femoral only revision. Mean gain in OHS 27.4. Dislocation rate 0.6% with a single event. Patients with a cemented Polished taper stem (PTS) had a Type B PPF rate of 2.1% requiring revision/fixation. Compared to conventional THA this cohort was significantly older (74.0 vs 68.3 years), more co-morbidity (ASA 3 46.5% vs 14.4%) and more non-OA indications (32.4% vs 8.5%). Every patient had at least one risk factor for falling and &gt;50% of cohort had 4 or more risk factors using NICE tool.We believe our results demonstrate that risk stratification successfully aids implant selection to prevent dislocation in high-risk patients. This novel design has provided excellent early results in a challenging cohort where individuals are very different to the “average” THA patient. NJR data on DM has reported an increase in revision for PPF. A “perfect storm” maybe created using DM in high-risk falls risk population. This re-enforces the need to consider all patient and implant factors when deciding bearing selection.

Soybean-mediated suppression of BjaI/BjaR1 quorum sensing in Bradyrhizobium diazoefficiens impacts symbiotic nitrogen fixation.

The acyl-homoserine lactones (AHLs)-mediated LuxI/LuxR quorum sensing (QS) system orchestrates diverse bacterial behaviors in response to changes in population density. The role of the BjaI/BjaR1 QS system in Bradyrhizobium diazoefficiens USDA 110, which shares homology with LuxI/LuxR, remains elusive during symbiotic interaction with soybean. Here this genetic system in wild-type (WT) bacteria residing inside nodules exhibited significantly reduced activity compared to free-living cells, potentially attributed to soybean-mediated suppression. The deletion mutant strain ΔbjaR1 showed significantly enhanced nodulation induction and nitrogen fixation ability. Nevertheless, its ultimate symbiotic outcome (plant dry weight) in soybeans was compromised. Furthermore, comparative analysis of the transcriptome, proteome, and promoter activity revealed that the inactivation of BjaR1 systematically activated and inhibited genomic modules associated with nodulation and nitrogen metabolism. The former appeared to be linked to a significant decrease in the expression of NodD2, a key cell-density-dependent repressor of nodulation genes, while the latter conferred bacterial growth and nitrogen fixation insensitivity to environmental nitrogen. In addition, BjaR1 exerted a positive influence on the transcription of multiple genes involved in a so-called central intermediate metabolism within the nodule. In conclusion, our findings highlight the crucial role of the BjaI/BjaR1 QS circuit in positively regulating bacterial nitrogen metabolism and emphasize the significance of the soybean-mediated suppression of this genetic system for promoting efficient symbiotic nitrogen fixation by B. diazoefficiens.IMPORTANCEThe present study demonstrates, for the first time, that the BjaI/BjaR1 QS system of Bradyrhizobium diazoefficiens has a significant impact on its nodulation and nitrogen fixation capability in soybean by positively regulating NodD2 expression and bacterial nitrogen metabolism. Moreover, it provides novel insights into the importance of suppressing the activity of this QS circuit by the soybean host plant in establishing an efficient mutual relationship between the two symbiotic partners. This research expands our understanding of legumes' role in modulating symbiotic nitrogen fixation through rhizobial QS-mediated metabolic functioning, thereby deepening our comprehension of symbiotic coevolution theory. In addition, these findings may hold great promise for developing quorum quenching technology in agriculture.

Organik ve kimyasal gübre ile kullanılmak üzere mikroorganizma izolasyon ve karakterizasyonu

Isolation and Characterization of Microorganisms for Use with Manure and Chemical Fertilizers&#x0D; Levent Değirmenci1, Özge Kaygusuz İzgördü2, Cihan Darcan3&#x0D; ORCID: 0000-0001-6608-0398; 0000-0002-3652-4266; 0000-0003-0205-3774&#x0D; 1 Corresponding author: Department of Chemical Engineering, Bilecik Şeyh Edebali University, 11210, Bilecik/Turkey Tel: +90 228 2141548, e-mail: levent.degirmenci@bilecik.edu.tr &#x0D; 2 Biotechnology Application and Research Center, Bilecik Şeyh Edebali University, 11210, Bilecik, Turkey 3 3Department of Molecular Biology and Genetics, Bilecik Şeyh Edebali University, 11210, Bilecik, Turkey&#x0D; &#x0D; Abstract&#x0D; A microbial consortium with the ability to utilize nitrogen of certain chemical fertilizers were established via a series of tests. Results indicated four strains, 3 of which were identified as Bacillus cereus sp and an Alcaligenes faecalis sp. which was the only non-Bacillus member of the consortium. The members of the consortium showed no antagonistic activity against each other implying their successful utilization as components of a commercial fertilizer.&#x0D; Keywords: IAA, siderophore, Bacillus spp., nitrogen fixation, ammonia/nitrite oxidation, MALDI-TOF MS&#x0D; &#x0D; Organik ve Kimyasal Gübre ,le Kullanılmak Üzere Mikroorganizma İzolasyon ve Karakterizasyonu&#x0D; &#x0D; Özet &#x0D; Farklı kimyasal gübrelerin içeriğinde yer alan azotu bitkinin kullanımına sunabilen mikroorganizma karışımı bir dizi testler sonucunda elde edilmiştir. Sonuçların değerlendirilmesiyle mikroorganizma karışımına üç Bacillus Cereus sp. suşu ile karışımın Bacillus sp. olmayan tek üyesi Alcaligenes faecalis sp. seçilmiştir. Mikroorganizma karışımında yer alan suşların birbirlerine karşı antagonistik etki göstermediği dolayısıyla karışımın mikrobiyal gübre olarak ticarileştirilmesinin mümkün olduğu da elde edilen sonuçlar arasındadır. &#x0D; Anahtar Kelimeler: IAA, siderophore, Bacillus spp. azot fiksasyonu, amonyum/nitrit oksidasyonu, MALDI-TOF MS&#x0D; 1. Introduction &#x0D; Chemical fertilizer is gaining an increasing attention and its harmful effects on environment possesses a serious threat [2]. Heavy metal accumulation is another problem during utilization of chemical fertilizers [2].The variation of soil pH, another problem encountered due to excessive fertilizer utilization, has negative impact on phosphorus uptake [3]. Plant growth promoting bacteria when added to soil, operate via certain mechanisms facilitating acquisition of already existing resources in soil [4]. Siderophore producing bacteria also acts as biocontrol agent capable of decreasing phytopathogen population in the flora [4–7].&#x0D; Certain procedures were developed and/or modified in the present study to obtain a microbial consortium which would act as an enhancer during plant growth. &#x0D; 2. Materials and Method&#x0D; &#x0D; 2.1. Semi-selective isolation procedure as starting-point&#x0D; &#x0D; Semi-selective isolation procedures were conducted according to [12]. &#x0D; 2.2. Standard tests applied to determine the potential of isolates as PGPB.&#x0D; &#x0D; Nitrogen fixation ability, IAA production, phosphate solubility siderophore production were conducted according to [13-18]. &#x0D; 2.3. Specified tests to determine nitrogen evaluation potential of PGP isolates&#x0D; &#x0D; Nitrogen evaluation potential was determined according to [19]. &#x0D; 2.4. Biochemical tests conducted to determine Bacillus sp. in accordance with MALDI-TOF MS analyses evaluated for validation. &#x0D; &#x0D; Biochemical tests were evaluated based on positive results for both caseinase activity and starch hydrolysis [20-22].&#x0D; MALDI-TOF MS analyses applied for selected strains and an isolate with positive activity towards siderophore production.&#x0D; 3. Results &#x0D; IAA production, Nitrogen fixation performance, Ammonifier selection, phosphate solubility, siderophore production ability, urea degradation, ammonium oxidation and nitrite oxidation abilities of strains were evaluated to establish a microbial consortium. &#x0D; 4. Conclusion and discussion&#x0D; • Media selection could serve as a selection criterion to assemble a certain group of microorganisms.&#x0D; • Tests conducted for isolates could be diversified to establish a consortium with modified properties.&#x0D; • Test procedures could be modified to facilitate establishment of microbial consortium.&#x0D; • Strains with different properties could serve as members of consortium which was the case in our study. &#x0D; • Identification in species level was possible to a certain extent. MALDI-TOF MS analysis presented a brief idea on strains and similar results would have been obtained in the case of applying its costlier alternatives. Hence a relatively simpler procedure is concluded to be better for initial investigation.&#x0D; • Evaluation of results led to investigation of certain prospects including determination of physicotolerant activity of strains and management of Fusarium wilt disease as the topics of future investigations.

Integrative Physiological, Transcriptome, and Proteome Analyses Provide Insights into the Photosynthetic Changes in Maize in a Maize-Peanut Intercropping System.

Intercropping is a traditional and sustainable planting method that can make rational use of natural resources such as light, temperature, fertilizer, water, and CO2. Due to its efficient resource utilization, intercropping, in particular, maize and legume intercropping, is widespread around the world. However, the molecular details of these pathways remain largely unknown. In this study, physiological, transcriptome, and proteome analyses were compared between maize monocropping and maize-peanut intercropping. The results show that an intercropping system enhanced the ability of carbon fixation and carboxylation of maize leaves. Apparent quantum yield (AQY), the light-saturated net photosynthetic rate (LSPn), the light saturation point (LSP), and the light compensation point (LCP) were increased by 11.6%, 9.4%, 8.9%, and 32.1% in the intercropping system, respectively; carboxylation efficiency (CE), the CO2 saturation point (Cisat), the Rubisco maximum carboxylation rate (Vcmax), the maximum electron transfer rate (Jmax), and the triose phosphate utilization rate (TPU) were increased by 28.5%, 7.3%, 18.7%, 29.2%, and 17.0%, respectively; meanwhile, the CO2 compensation point (Γ) decreased by 22.6%. Moreover, the transcriptome analysis confirmed the presence of 588 differentially expressed genes (DEGs), and the numbers of up-regulated and down-regulated genes were 383 and 205, respectively. The DEGs were primarily concerned with ribosomes, plant hormone signal transduction, and photosynthesis. Furthermore, 549 differentially expressed proteins (DEPs) were identified in the maize leaves in both the maize monocropping and maize-peanut intercropping systems. Bioinformatics analysis revealed that 186 DEPs were related to 37 specific KEGG pathways in each of the two treatment groups. Based on the physiological, transcriptome, and proteome analyses, it was demonstrated that the photosynthetic characteristics in maize leaves can be improved by maize-peanut intercropping. This may be related to PS I, PS II, cytochrome b6f complex, ATP synthase, and photosynthetic CO2 fixation, which is caused by the improved CO2 carboxylation efficiency. Our results provide a more in-depth understanding of the high yield and high-efficiency mechanism in maize and peanut intercropping.