Characterization and prebiotic potential of polysaccharides from Rosa roxburghii Tratt pomace by ultrasound-assisted extraction.

In this study, polysaccharides (RRTPs) were extracted from Rosa roxburghii Tratt pomace by hot water or ultrasound (US)-assisted extraction. The structural properties and potential prebiotic functions of RRTPs were investigated. Structural characterization was conducted through HPAEC, HPGPC, GC-MS, FT-IR and SEM. Chemical composition analysis revealed that RRTPs extracted by hot water (RRTP-HW) or US with shorter (RRTP-US-S) or longer duration (RRTP-US-L) all consisted of galacturonic acid, galactose, glucose, arabinose, rhamnose and glucuronic acid in various molar ratio. US extraction caused notable reduction in molecular weight of RRTPs but no significant changes in primary structures. Fecal fermentation showed RRTPs could reshape microbial composition toward a healthier balance, leading to a higher production of beneficial metabolites including total short-chain fatty acids, curcumin, noopept, spermidine, 3-feruloylquinic acid and citrulline. More beneficial shifts in bacterial population were observed in RRTP-HW group, while RRTP-US-S had stronger ability to stimulate bacterial short-chain fatty acids production. Additionally, metabolic profiles with the intervention of RRTP-HW, RRTP-US-S or RRTP-US-L were significantly different from each other. The results suggested RRTPs had potential prebiotic effects which could be modified by power US via molecular weight degradation.

Phosphate-Solubilizing Capacity of Paecilomyces lilacinus PSF7 and Optimization Using Response Surface Methodology.

Phosphorus-solubilizing microorganisms release organic acids that can chelate mineral ions or reduce the pH to solubilize insoluble phosphates for use by plants; it is important to study potential phosphorus-solubilizing microorganisms for use in agriculture. In this study, PSF7 was isolated from the soil of the Wengfu Phosphorus Tailings Dump in Fuquan City, Guizhou Province, China. PSF7 was identified as Paecilomyces lilacinus, based on morphological characterization and ITS sequencing analysis. The relationship between the phosphorus-solubilizing capacity and pH variation of PSF7 under liquid fermentation was studied. The results showed that there was a significant negative correlation (-0.784) between the soluble phosphorus content of PSF7 and the pH value. When PSF7 was placed under low phosphorus stress, eight organic acids were determined from fermentation broth using HPLC, of which tartaric acid and formic acid were the main organic acids. Different optimization parameters of medium components were analyzed using response surface methodology. The optimized medium components were 23.50 g/L sucrose, 1.64 g/L ammonium sulfate and soybean residue, 1.07 g/L inorganic salts, and 9.16 g/L tricalcium phosphate, with a predicted soluble phosphorus content of 123.89 mg/L. Under the optimum medium composition, the actual phosphorus-solubilizing content of PSF7 reached 122.17 mg/L. Moreover, scanning electron microscopy analysis of the sample was carried out to characterize the phosphate-solubilizing efficiency of PSF7 on mineral phosphate. The results provide useful information for the future application of PSF7 as a biological fertilizer.

Thermoflavimicrobium daqui sp. nov., a thermophilic microbe isolated from Moutai-flavour Daqu.

Moutai-flavour Daqu is an important starter to support growth of microorganisms in the fermented process of Moutai-flavour liquor. A novel thermophilic microorganism, designated strain FBKL4.011T, was isolated from Moutai-flavour Daqu samples collected from Guotai distillery in Renhuai, Guizhou province, south-west China. The strain could grow at 45-65 °C (optimum 45 °C). Based on polyphasic analysis, strain FBKL4.011T was affiliated to the genus Thermoflavimicrobium. It formed abundant pale-yellow aerial and substrate mycelium, bearing single endospores (7.0-10.0 µm diameter) on branched long sporophores (5.0 µm diameter). The cell-wall peptidoglycan contained meso-diaminopimelic acid; ribose, glucose and mannose were the primary whole-cell sugars. The major fatty acids were iso-C14 : 0, iso-C15 : 0, anteiso-C15 : 0 and iso-C16 : 0. The predominant menaquinone were MK-8 and MK-9. The polar phospholipids contained diphosphatidyl glycerol, phosphatidyl ethanolamine, one unidentified phospholipid and one unidentified lipid. The G+C content of the genome was 43.1 mol%. According to the 16S rRNA gene sequence analysis, strain FBKL4.011T was closely related to Thermoflavimicrobium dichotomicum JCM 9688T (95.3 % sequence similarity), and other members within the family Thermoactinomycetaceae (less than 93.0 % sequence similarity). The DNA-DNA hybridisation data showed low relatedness between strain FBKL4.011T and T. dichotomicum JCM 9688T, Laceyella sacchari KCTC 9790T, Laceyella tengchongensis YIM 10002T, Laceyella sediminis RHA1T(36.7±1.1 %, 30.0±1.2 %, 21.3±2.1 % % and 37.6±0.9 %, respectively). Based on data from the polyphasic analysis, strain FBKL4.011T is considered to represent a novel species of the genus Thermoflavimicrobium, for which the name Thermoflavimicrobium daqui sp. nov. is proposed. The type strain is FBKL4.011T(=KCTC 43036T=CICC 24504T).

Effects of intermedin on dorsal root ganglia in the transmission of neuropathic pain in chronic constriction injury rats.

Neuropathic pain is a common and severely disabling state that affects millions of people worldwide. The P2X3 receptor plays a crucial role in facilitating pain transmission. Intermedin (IMD), which is also known as adrenomedullin 2 (AMD2) is a newly discovered hormone that is a member of the calcitonin/calcitonin gene-related peptide family. The present research investigates the effects of IMD on pain transmission in neuropathic pain states as mediated by P2X3 receptors in dorsal root ganglia (DRG). Chronic constriction injury (CCI) rats were used as the neuropathic pain model. Adult male Sprague-Dawley rats were randomly assigned to five groups as follows: blank control group (Control), sham operation group (Sham), CCI rats treated with saline group (CCI+NS), CCI rats treated with IMD1-53 group (CCI+IMD1-53 ), and CCI rats treated with IMD inhibitor IMD14-47 group (CCI+IMD14-47 ). The mechanical withdrawal threshold (MWT) was tested by the von Frey method, and the thermal withdrawal latency (TWL) was tested via automatic thermal stimulus instruments. Changes in the expression of P2X3 receptors and IMD in CCI rat L4/L5 DRG were detected using immunohistochemistry, reverse transcription-polymerase chain reaction, and Western blotting. After treatment with intrathecal injection (i.t.), mechanical and thermal hyperalgesia in the CCI+IMD1-53 group was maintained, but MWT and TWL in the CCI+IMD14-47 groups increased. The expression levels of P2X3 receptors and IMD in L4/L5 DRG in the CCI+NS and CCI+IMD1-53 groups were significantly increased compared with those in the Control group or the Sham group. After application of IMD14-47 in CCI rats, there was a decrease in the expression levels of P2X3 receptors and IMD in L4/L5 DRG. The phosphorylation of p38 and ERK1/2 in L4/L5 DRG in the CCI+NS group and the CCI+IMD1-53 group was stronger than that in the Control group or the Sham group; however, the phosphorylation of p38 and ERK1/2 in the CCI+IMD14-47 group was much lower than that in the CCI+NS group or the CCI+IMD1-53 group. Our findings indicate that IMD might increase the sensitization effects of IMD on P2X3 receptors to alleviate chronic neuropathic pain injury. The IMD agonist IMD1-53 might enhance nociceptive responses mediated by P2X3 receptors in neuropathic pain, and the IMD inhibitor IMD14-47 could inhibit the sensitization of the P2X3 receptor in chronic neuropathic pain injury.