Search Results (14)

This study investigated the isolation and formulation of a bacterial conditioner as a biostimulant for Triticum durum (durum wheat) under salinity stress. An Algerian alkaline–saline soil was sampled, characterized for its physical and chemical characteristics and its culturable and total microbial community (16S rRNA gene metabarcoding). Three bacterial strains showing high 16S rRNA gene similarity to Pseudomonas putida, Bacillus proteolyticus, and Niallia nealsonii were selected for their plant growth-promoting (PGP) traits under different salinity levels, including phosphate solubilisation (194 µg mL⁻¹), hormone production (e.g., gibberellin up to 56 µg mL⁻¹), and good levels of hydrocyanic acid, ammonia, and siderophores. N. nealsonii maintained high indole production under saline conditions, while B. proteolyticus displayed enhanced indole synthesis at higher salt concentrations. Siderophore production remained stable for P. putida and N. nealsonii, whereas for B. proteolyticus a complete inhibition was registered in the presence of salt stress. The consortium density and application were tested under controlled conditions using Medicago sativa as a model plant. The effective biostimulant formulation was tested on Triticum durum under greenhouse experiments. Bacterial inoculation significantly improved plant growth in the presence of salt stress. Root length increased by 91% at 250 mM NaCl. Shoot length was enhanced by 112% at 500 mM NaCl. Total chlorophyll content increased by 208% at 250 mM NaCl. The chlorophyll a/b ratio increased by 117% at 500 mM. Also, reduced amounts of plant extracts were necessary to scavenge 50% of radicals (−22% at 250 mM compared to the 0 mM control). Proline content increased by 20% at both 250 mM and 500 mM NaCl. These results demonstrate the potential of beneficial bacteria as biostimulants to mitigate salt stress and enhance plant yield in saline soils. Full article

Defining life is an arduous task that has puzzled philosophers and scientists for centuries. Yet biology suffers from a lack of clear definition, putting biologists in a paradoxical situation where one can describe at the atomic level complex objects that remain globally poorly defined. One could assume that such descriptions make it possible to perfectly characterize living systems. However, many cases of misinterpretation put this assumption into perspective. In this article, we focus on critical parameters such as time, water, entropy, space, quantum properties, and electrostatic potential to redefine the nature of living matter, with special emphasis on biological coding. Where does the DNA double helix come from, why cannot the reproduction of living organisms occur without mutations, what are the limitations of the genetic code, and why do not all proteins have a stable three-dimensional structure? There are so many questions that cannot be resolved without considering the aforementioned parameters. Indeed, (i) time and space constrain many biological mechanisms and impose drastic solutions on living beings (enzymes, transporters); (ii) water controls the fidelity of DNA replication and the structure/disorder balance of proteins; (iii) entropy is the driving force of many enzymatic reactions and molecular interactions; (iv) quantum mechanisms explain why a molecule as simple as hydrocyanic acid (HCN) foreshadows the helical structure of DNA, how DNA is stabilized, why mutations occur, and how the Earth magnetic field can influence the migration of birds; (v) electrostatic potential controls epigenetic mechanisms, lipid raft functions, and virus infections. We consider that raising awareness of these basic parameters is critical for better understanding what life is, and how it handles order and chaos through a combination of genetic and epigenetic mechanisms. Thus, we propose to incorporate these parameters into the definition of life. Full article

The set of TX₃-TrX₂ (T = C, Si, Ge; Tr = B, Al, Ga; X = F, Cl, Br) molecules offers a rather unique opportunity to study both σ-hole and π-hole dimerization on the tetrel and triel ends, respectively. According to the molecular electrostatic potential (MEP) distribution, the π-hole extrema (acidic sites) were more intense than their σ-hole counterparts. The molecules owning the most (CX₃-AlX₂) and least (SiX₃-BX₂) intense π-holes were chosen to evaluate their capacities to attract one and two HCN molecules (Lewis bases). We discovered that the energetic characteristics of π-hole dimers severely conflict with the monomers MEP pattern since the weakest π-hole monomer forms a dimer characterized by interaction energy compared to those created by the monomers with noticeably greater power in the π-hole region. This outcome is due to the deformation of the weakest π-hole donor. Furthermore, the MEP analysis for monomers in the geometry of respective dimers revealed a “residual π-hole” site that was able to drive second ligand attachment, giving rise to the two “unusual trimers” examined further by the NCI and QTAIM analyses. Apart from them, the π-hole/π-hole and σ-hole/π-hole trimers have also been obtained throughout this study and described using energetic and geometric parameters. The SAPT approach revealed details of the bonding in one of the “unusual trimers”. Finally, Born-Oppenheimer Molecular Dynamics (BOMD) simulations were carried out to investigate the time evolution of the interatomic distances of the studied complexes as well as their stability. Full article

Fresh cassava root is not recommended for animal feeding due to high quantities of hydrocyanic acid (HCN), which produces symptoms of poisoning. The purpose of this study was to find out how a rhodanese enzyme addition affects rumen fermentation, HCN content, feed utilization, and blood metabolites in beef calves fed fresh cassava root. Four Thai native beef cattle with an initial body weight (BW) of 95 ± 10.0 kg (1–1.5 years old) were randomly allocated to receive fresh cassava root containing HCN at 0, 300, 450, and 600 ppm according to a 4 × 4 Latin square design. Rice straw was the basal diet. The rhodanese enzyme was combined with concentrated feeds at a concentration of 1 mg/10⁴ ppm HCN. The fresh cassava root was cleaned to remove dirt and chopped into 3 to 5 mm sized pieces before being fed to the animals at their various levels. The total feed intake of beef cattle increased when fed with fresh cassava root (p < 0.05). The digestibility of crude protein (CP) was different among various fresh cassava root levels (p < 0.05). Ruminal ammonia-N levels were measured 4 hours after feeding, and the average concentration declined considerably in animals fed fresh cassava root at 300–600 ppm HCN (p < 0.05). Cyanide concentration in the rumen was linearly increased by 270.6% (p < 0.05) when it was supplemented with a high level of fresh cassava root. Blood urea-N concentration was altered and decreased when supplemented with fresh cassava root (p < 0.01). The blood thiocyanate concentration was altered by the levels of fresh cassava root and rhodanese enzyme, which ranged from 4.1 to 27.9 mg/dL (p < 0.01). Cattle given fresh cassava root showed no influence on total volatile fatty acid, acetic acid, or butyric acid concentrations in the rumen (p > 0.05). However, the concentration of propionic acid increased slightly (p < 0.05) 4 hours after feeding. Supplementing fresh cassava root up to 600 ppm HCN/day improved N absorption, retention, and the proportion of N retention to N intake (p < 0.05). Therefore, increasing the inclusion of fresh cassava root with a rhodanese enzyme addition improves total feed intake, CP digestibility, nitrogen utilization, blood thiocyanate, and propionate concentrations, which may remove HCN without harming animal health. Full article

Sorghum–sudangrass (Sorghum bicolor × S. sudanense (Piper) Stapf.) and pearl millet (Pennisetum glaucum (L.) R. Br.) provide adequate nutritive value for growing beef cattle; however, unlike pearl millet, sorghum–sudangrass produces hydrocyanic acid (which is toxic to livestock) when frosted. Forage yield, nutritive value, and weight gain of growing cattle grazing sorghum–sudangrass and pearl millet were compared during the frost-prone autumns of 2013 and 2014, at New Mexico State University’s Rex E. Kirksey Agricultural Science Center in Tucumcari, NM USA, in randomized complete block designs each year with two replicates. No differences existed between pearl millet and sorghum–sudangrass forage yield, although there was a year–forage interaction for fiber-based nutritive value components because of maturity differences across years between the forages when freeze-killed. Pearl millet allowed for extending grazing of available forage for an additional 14 and 24 d in 2013 and 2014, respectively, compared to sorghum–sudangrass during the frost-prone autumn periods. During that period, when sorghum forages produce potentially toxic levels of hydrocyanic acid, animals grazing pearl millet accumulated an additional average of 94.9 kg live-weight gain ha⁻¹ (p < 0.001). These factors afford producers an opportunity to increase returns on the similar investments of establishing and managing warm-season annual forage crops each year, and allow more time to stockpile cool-season perennial and annual forages for winter and early spring grazing, or to reduce hay feeding. Full article

This study aimed to characterize the halotolerant capability, in vitro, of selected actinomycetes strains and to evaluate their competence in promoting halo stress tolerance in durum wheat in a greenhouse experiment. Fourteen isolates were tested for phosphate solubilization, indole acetic acid, hydrocyanic acid, and ammonia production under different salt concentrations (i.e., 0, 0.25, 0.5, 0.75, 1, 1.25, and 1.5 M NaCl). The presence of 1-aminocyclopropane-1-carboxylate deaminase activity was also investigated. Salinity tolerance was evaluated in durum wheat through plant growth and development parameters: shoot and root length, dry and ash-free dry weight, and the total chlorophyll content, as well as proline accumulation. In vitro assays have shown that the strains can solubilize inorganic phosphate and produce indole acetic acid, hydrocyanic acid, and ammonia under different salt concentrations. Most of the strains (86%) had 1-aminocyclopropane-1-carboxylate deaminase activity, with significant amounts of α-ketobutyric acid. In the greenhouse experiment, inoculation with actinomycetes strains improved the morpho-biochemical parameters of durum wheat plants, which also recorded significantly higher content of chlorophylls and proline than those uninoculated, both under normal and stressed conditions. Our results suggest that inoculation of halotolerant actinomycetes can mitigate the negative effects of salt stress and allow normal growth and development of durum wheat plants. Full article

Introduction of quinoa (Chenopodium quinoa willd.), a gluten-free nutritious pseudo-cereal, outside its traditional growing areas exposed it to seedling damping-off. Here, we isolated eleven phosphate-solubilizing bacteria from the quinoa rhizosphere and assessed their effect on germination and seedlings growth. All isolates solubilized phosphate, produced indole3-acetic acid, hydrocyanic acid, siderophores, and ammonia. Genotypic analysis revealed that our strains are related to the genus of Bacillus, Pseudomonas, and Enterobacter. Strains Enterobacter asburiae (QD14, QE4, QE6, and QE16), Enterobacter sp. QE3, and Enterobacter hormaechei QE7 withstood 1.5 mg·L⁻¹ of cadmium sulfate, 0.5 mg·mL⁻¹ of nickel nitrate, and 1 mg·mL⁻¹ of copper sulfate. Moreover, all strains solubilized zinc from ZnO; P. Stutzeri QD1 and E. asburiae QD14 did not solubilize Zn₃(PO₄)₂ and CO₃Zn, whereas CO₃Zn was not solubilized by E. asburiae QE16. Bacillus atrophaeus S8 tolerated 11% NaCl. P. frederiksbergensis S6 and Pseudomonas sp. S7 induced biofilm formation. Anti-fusarium activity was demonstrated for E.asburiae QE16, P. stutzeri QD1, P. frederiksbergensis S6, Pseudomonas sp. S7, and B. atrophaeus S8. Lastly, inoculation of quinoa seeds with B. atrophaeus S8 and E. asburiae QB1 induced the best germination rate and seedling growth, suggesting their potential use as inoculants for salty and heavy metal or zinc contaminated soils. Full article

Botrytis cinerea infection can be very devastating for tomato production, as it can result in a large-scale reduction in tomato fruit production and fruit quality after harvest. Thus, it negatively affects tomato yield and quality. In this study, a biocontrol bacteria CQ-4 was isolated and screened from the rhizosphere soil of tomato plants. Morphological, physiological, and biochemical characteristics and 16S rDNA sequence analysis revealed that it belongs to the species Pseudomonas aeruginosa, which has a strong antagonistic effect against Botrytis cinerea. In addition, the bacterium’s antibacterial spectrum is relatively extensive, and antagonistic tests have shown that it also has varying degrees of inhibition on other 12 plant diseases. The growth promotion test showed that the strain has a clear promotion effect on tomato seed germination and seedling growth. The growth-promoting effect on plant height, stem thickness, dry and fresh weight and main root length of tomato seedlings was significantly improved after the seeds were soaked in a bacterial solution of 2.5 × 10⁸ cfu mL⁻¹ concentration. This did not only maintain the nutritional quality of tomato fruits, but also prevents them from rotting. In vitro and pot experiments showed that the strain CQ-4 can effectively control tomato gray mold, and the control effects on tomato leaves and fruits reached 74.4% and 66.0%, respectively. Strain CQ-4 induce plants to up-regulate the activities of four disease-resistant defense enzymes. The peak enzymatic activities of Phenylalanine Ammonia Lyase (PAL), polyphenol oxidase (PPO), peroxidase (POD), and Superoxide Dismutase (SOD) were increased by 35.6%, 37.6%, 46.1%, and 38.4%, respectively, as compared with the control group. This study found that the strain can solubilize phosphorus, fix nitrogen, and produce cellulase, protease, ferrophilin, and other antibacterial metabolites, but it does not produce chitinase, glucanase, and HCN (hydrocyanic acid). This research screened out an excellent Pseudomonas aeruginosa strain that can stably and effectively control tomato gray mold, and it provided theoretical basis for further development and the application of biological agents. Full article

Monilinia fructigena is one of the most important fungal pathogens causing brown rot on apple and is heavily affecting fruit production. The main objective of this study was to screen for potential bacterial isolates with higher antagonistic activity against M. fructigena. Our study focused on the identification of potential bacterial isolates capable of reducing both the mycelial growth of M. fructigena and the disease severity using in vitro and in planta trials, respectively. To achieve this goal, thirteen bacteria, isolated from natural soil, were evaluated for their abilities to produce lytic enzymes (amylase, cellulase and protease), hydrocyanic acid (HCN) and lipopeptides (bacillomycin, fengycin, iturin and surfactin). Further, results from the dual culture method, volatile and bacterial free-cell filtrate bioassays indicated that tested isolates showed a fungicidal activity against the mycelial growth of M. fructigena. Thus, out of the 13 isolates tested, 12 exhibited significant mycelial inhibition (more than 70%) against M. fructigena, while remaining the last isolate displayed only a partial inhibition (up to 43%). Further, 12 of the bacteria isolates displayed an amylase production, 10 showed cellulase production, 11 revealed protease production, while only 2 displayed HCN production. In addition, most bacterial isolates were found to have genes encoding for different lipopeptides: bacillomycin (10), fengycin (3), iturin (11) and surfactin (1). Interestingly, two bacterial isolates, Bacillus amyloliquefaciens B10W10 and Pseudomonas sp. B11W11 were found to be the most effective and displayed the lowest disease severity in planta trial. These two bacteria reduced the brown rot incidence compared to the synthetic fungicide in a semi-commercial large-scale trial. Therefore, our findings suggest that these two later bacterial isolates provide apple protection against M. fructigena via direct and indirect mechanisms. These isolates may be used, therefore, as potential biological control agents (BCAs) in preventive treatment to control brown rot disease on apple fruits. Full article

The nickel-catalyzed addition of Hydrocyanic acid (HCN) to butadiene usually leads to a mixture of the branched 2-methyl-3-butenenitrile (2M3BN) and the linear 3-pentenenitrile (3PN) with a 30:70 ratio by employing mono-dentate phosphites, while a 97% selectivity to 3PN is obtained using a 1,4-bis(diphenyphosphino)butane (dppb) ligand and Ni(COD)₂ (1,5-Cyclooctadiene) as catalysts. To explain this phenomenon, a reasonable mechanism of the hydrocyanation, involving the cyano (CN) migration (for 3PN) and the methylallyl rotation (for 2M3BN) pathways, is proposed. The key intermediates and the rate-determining steps in the pathways have been illustrated. The methylallyl rearrangement is the rate-determining step in the formation of 3PN while the reductive elimination governs the reaction to 2M3BN, which is subsequently isomerized to 3PN. Moreover, the opposite changes of the bite angle of the intermediates and transition states explain how the reactions proceed in two different directions. Full article

Excessive use of chemical products in agriculture is causing significant environmental pollution and the loss of lands and fertility of agricultural soils. Plant-growth-promoting bacteria are a valid alternative strategy for sustainable agriculture. The aim of this study was to select actinomycete strains based on their plant-growth-promoting traits and to investigate their root association abilities and biostimulant effects on Solanum lycopersicum. The strains were investigated for their phosphate solubilization ability, production of indole-3-acetic acid, hydrocyanic acid, and ammonia, and several enzymatic activities. Bacteria–plant-root associations were studied by scanning electron microscopy. A greenhouse experiment was carried out to assess inoculation effects. Of sixty isolates, fourteen strains showed significant plant-growth-promoting traits. All fourteen strains solubilized phosphate, produced ammonia, and showed several enzymatic activities at different rates. The production of indole-3-acetic acid was shown by nine strains, while hydrocyanic acid production was observed in eleven of them. Scanning electron microscopy revealed that strains have good in vitro plant root association and colonization abilities. In planta inoculation by actinomycete strains positively influenced plant growth parameters. The best results were shown by seven actinomycete strains, suggesting their possible utilization as biofertilizer agents for sustainable agriculture. Full article

Prunus serotine seed, was processed to produce a defatted flour (71.07 ± 2.10% yield) without hydrocyanic acid. The total protein was 50.94 ± 0.64%. According to sensory evaluation of cookies with P. serotine flour, the highest score in overall impression (6.31) was at 50% flour substitution. Its nutritional composition stood out for its protein and fiber contents 12.50% and 0.93%, respectively. Protein concentrate (PsPC) was elaborated (81.44 ± 7.74% protein) from defatted flour. Emulsifying properties of PsPC were studied in emulsions at different mass fractions; ϕ = 0.002, 0.02, 0.1, 0.2, and 0.4 through physicochemical analysis and compared with whey protein concentrate (WPC). Particle size in emulsions increased, as did oil content, and results were reflected in microscope photographs. PsPC at ϕ 0.02 showed positive results along the study, reflected in the microphotograph and emulsifying stability index (ESI) test (117.50 min). At ϕ 0.4, the lowest ESI (29.34 min), but the maximum emulsifying activity index (EAI) value (0.029 m²/g) was reached. WPC had an EAI value higher than PsPC at ϕ ≥ 0.2, but its ESI were always lower in all mass fraction values. PsPC can compete with emulsifiers as WPC and help stabilize emulsions. Full article

Several million tons of end of life tires (ELTs) are piled annually as a result of human activities. Various methods have been proposed for the extraction and recycling of the resource potential of ELTs. The chemical composition of ELTs seems to enable their usage as a fuel after mechanical separation of a steel cord. Indeed, in the rubber of ELTs, up to 90 mass% accounts for carbon and hydrogen. Currently, it is by incineration that a significant proportion of ELTs is utilized. However, ELTs contain not only sulfur, which is used for vulcanization, but also nitrogen-containing additives. The behavior of these heteroatoms during oxidation is poorly investigated. It has been shown that the pyrolysis liquid fuel obtained from ELTs contains such sulfur compounds as mercaptans and nitrogen in the form of hydrocyanic acid and cyanogen. Deep oxidation of ELTs results in the oxidation of sulfur compounds to dioxide, but the oxidation products have been found to contain traces of cyanogen. Taking this into account, one should pay attention to the ways of transforming heteroatoms during the process of ELT oxidation and the products of ELT pyrolysis as potential sources of highly toxic gas emissions. Full article

The influence of sulfur included in fermented total mixed ration (FTMR) containing fresh cassava root on rumen characteristics, microbial protein synthesis, and blood metabolites in cattle was evaluated. Four Thai native beef cattle were randomly assigned according to a 2 × 2 factorial in a 4 × 4 Latin square design, and dietary treatments were as follows: factor A included a level of sulfur at 1% and 2% in total mixed ration, and factor B featured ensiling times at zero and 7 days. Digestibility of dry matter was increased when FTMR was supplemented with 2% sulfur. Blood thiocyanate increased by 69.5% when ensiling time was 7 days compared to no ensiling (p < 0.01). Bacterial populations were significantly different in the FTMR containing sulfur at 2% and 7 days of ensiling. Furthermore, microbial crude protein and efficiency of microbial protein synthesis were higher in the FTMR containing 2% sulfur and 7 days of ensiling (p < 0.01). Thus, high levels of hydrocyanic acid from fresh cassava root could be detoxified by a sulfur addition with an ensiling process to become nontoxic to cattle. Full article