Saccharopolyspora mangrovi sp. nov., a novel mangrove soil actinobacterium with distinct metabolic potential revealed by comparative genomic analysis.

A novel mangrove soil-derived actinomycete, strain S2-29T, was found to be most closely related to Saccharopolyspora karakumensis 5K548T based on 16 S rRNA sequence (99.24% similarity) and genomic phylogenetic analyses. However, significant divergence in digital DNA-DNA hybridization, average nucleotide identity, and unique biosynthetic gene cluster possession distinguished S2-29T as a distinct Saccharopolyspora species. Pan genome evaluation revealed exceptional genomic flexibility in genus Saccharopolyspora, with > 95% accessory genome content. Strain S2-29T harbored 718 unique genes, largely implicated in energetic metabolisms, indicating different metabolic capacities from its close relatives. Several uncharacterized biosynthetic gene clusters in strain S2-29T highlighted the strain's untapped capacity to produce novel functional compounds with potential biotechnological applications. Designation as novel species Saccharopolyspora mangrovi sp. nov. (type strain S2-29T = JCM 34,548T = CGMCC 4.7716T) was warranted, expanding the known Saccharopolyspora diversity and ecology. The discovery of this mangrove-adapted strain advances understanding of the genus while highlighting an untapped source of chemical diversity.

Occurrence state of fluoride in barite ore and the complexation leaching process.

Barite ore is typically associated with difficult-to-remove vein minerals, but commercial barite products require a high BaSO4 content. We investigated the occurrence state of fluoride in barite ore using various analytical techniques, which indicated that elemental fluorine in barite predominantly exists as fluorite. Fluoride was then leached from barite ore via complexation. The effects of HCl and AlCl3 concentrations, temperature, time, and liquid-solid ratio on the leaching rate were examined, and the leaching conditions were optimized using an orthogonal array method. The fluorine leaching rate approached 93.11% after stirring for 30 min at 90 °C and 300 rpm with 3 mol/L HCl, 0.4 mol/L AlCl3, a liquid-solid ratio of 10:1 mL/g, and an ore sample size of -75 µm + 48 µm. According to the leaching kinetics, the process conformed to the solid membrane diffusion control model at a high temperature and the joint chemical reaction-diffusion control model at a low temperature. The apparent activation energy was 56.88 kJ/mol. Furthermore, aluminum and fluorine coordination numbers increased with increasing Al3+/F- molar concentration ratios. Competing complexation reactions of Al3+, H+, and F- occurred at three levels. This complexation approach effectively leaches fluoride from barite, improves barite product quality, and reduces environmental pollution.

Thermogravimetric and spectroscopic analyses along with the kinetic modeling of the pyrolysis of phosphate tailings.

The present study aimed to understand the pyrolysis characteristics of phosphorus tailings and promote the resource utilization of phosphorus tailings. Thermogravimetry was combined with Fourier transform infrared spectroscopy-Raman spectroscopy-mass spectrometry (TG-FTIR-RS-MS) and kinetic models to investigate the possible reaction mechanisms during the pyrolysis of phosphorus tailings and the changes in the release characteristics of pyrolysis volatiles. The results showed that the pyrolysis process occurred in three different stages. First, small amounts of adsorbed water were removed, and organic matter in the tailings was decomposed. Second, CaMg(CO3)2 underwent thermal decomposition to produce CaCO3, MgO, and CO2. Third, CaCO3 further decomposed into CaO and CO2. Similarly, the pyrolysis kinetics were divided into three intervals based on the differences in their activation energy values. The pyrolysis reaction mechanism functions were two-dimensional diffusion (Valensi model), nucleation and growth (Avrami-Erofeev, n = 1/2), and nucleation and growth (Avrami-Erofeev, n = 1/4). The gases released during the pyrolysis of phosphate tailings were mainly CO2, F2, and HF.

Determination of barium sulfate in barite ore by phase conversion-partial pressure-corrected headspace gas chromatography.

Barium sulfate (BaSO4) content is used to evaluate the grade of barite ore. In the present study, we report a method to determine the BaSO4 content in barite ore by phase conversion-headspace gas chromatography with partial pressure correction. In this method, the ore sample is roasted with sodium carbonate and potassium carbonate after pretreatment with hydrochloric acid. The roasted product is subsequently placed in a closed headspace bottle to react with hydrochloric acid. The ratio of CO2 to O2 signals is detected by a thermal conductivity detector for gas chromatography. Finally, the BaSO4 content in barite ore is calculated using this ratio. The method demonstrates good precision (relative standard deviation < 0.84%) and accuracy (relative error < 3.40%), with the uncertainty at 95% confidence interval at approximately +/- 0.57%. Moreover, this approach is expected to be used for the batch testing of BaSO4 content in barite ores in industrial applications.

Poly[diaqua-bis(µ(3)-1H-benzimidazole-5,6-dicarboxyl-ato-κN:O,O:O)bis-(µ(2)-1H,3H-benzimidazolium-5,6-dicarboxyl-ato-κO,O:O)digadolinium(III)].

In the title complex, [Gd(2)(C(9)H(4)N(2)O(4))(2)(C(9)H(5)N(2)O(4))(2)(H(2)O)(2)](n), two of the benzimidazole-5,6-dicarboxyl-ate ligands are pro-ton-ated at the imidazole groups. Each Gd(III) ion is coordinated by six O atoms and one N atom from five ligands and one water mol-ecule, displaying a distorted bicapped trigonal-prismatic geometry. The Gd(III) ions are linked by the carboxyl-ate groups and imidazole N atoms, forming a layer parallel to (001). These layers are further connected by O-H⋯O and N-H⋯O hydrogen bonds into a three-dimensional supra-molecular network.

Poly[[aqua-(µ(2)-oxalato)(µ(2)-2-oxido-pyridinium-3-carboxylato)dysprosium(III)] monohydrate].

In the title complex, {[Dy(C(6)H(4)NO(3))(C(2)O(4))(H(2)O)]·H(2)O}(n), the Dy(III) ion is coordinated by seven O atoms from two 2-oxidopyridinium-3-carboxylate ligands, two oxalate ligands and one water mol-ecule, displaying a distorted bicapped trigonal-prismatic geometry. The carboxyl-ate groups of the 2-oxidopyridinium-3-carboxylate and oxalate ligands link dysprosium metal centres, forming layers parallel to (100). These layers are further connected by inter-molecular O-H⋯O hydrogen-bonding inter-actions involving the coordin-ated water mol-ecules, forming a three-dimensional supra-molecular network. The uncoordinated water mol-ecule is involved in N-H⋯O and O-H⋯O hydrogen-bonding inter-actions within the layer.

Hemi(4,4'-bipyridinium) hexa-fluorido-phosphate bis-(4-amino-benzoic acid) 4,4'-bipyridine monohydrate.

In the title compound, 0.5C(10)H(10)N(2) (2+)·PF(6) (-)·C(10)H(8)N(2)·2C(7)H(7)NO(2)·H(2)O, the cation is located on a center of symmetry. The crystal structure is determined by a complex three-dimensional network of inter-molecular O-H⋯O, O-H⋯N, N-H⋯N and N-H⋯F hydrogen bonds. π-π stacking inter-actions between neighboring pyridyl rings are also present; the centroid-centroid distance is 3.643 (5) Å. The hexa-fluoridophosphate anion is disordered over two positions with site-occupancy factors of ca 0.6 and 0.4.