Celastrol inhibits mouse B16-F10 melanoma cell survival by regulating the PI3K/AKT/mTOR signaling pathway and repressing HIF-1α expression.

OBJECTIVE: Melanoma, with its high degree of malignancy, stands as one of the most dangerous skin cancers and remains the primary cause of death from skin cancer. With studies demonstrating the potential of traditional Chinese medicine to intervene and treat melanoma, we turned our attention to celastrol. Celastrol is a triterpene compound extracted from the traditional Chinese medicine derived from Tripterygium wilfordii. Previous studies have shown that celastrol exerts inhibitory effects on various malignant tumors, including melanoma. Hence, our goal was to clarify the impact of celastrol on cell viability, apoptosis, and cell cycle progression by elucidating its effects on the PI3K/AKT/mTOR pathway. METHODS: CCK-8 and wound healing assays were used to determine the effect of celastrol on the viability and migration of B16-F10 cells. Changes in cell apoptosis, cell cycle, reactive oxygen species (ROS), and mitochondrial membrane potential were detected by flow cytometry. PI3K/AKT/mTOR pathway proteins and HIF-α mRNA expression in B16-F10 cells were detected by western blotting and qPCR. Moreover, the addition of a PI3K activator demonstrated that celastrol could inhibit the function of B16-F10 cells via the PI3K/AKT/mTOR pathway. RESULTS: Celastrol inhibited the viability and migration of B16-F10 cells. Through the inhibition of the PI3K/AKT/mTOR pathway down-regulates the expression of HIF-α mRNA, thereby causing an increase of ROS in cells and a decrease in the mitochondrial membrane potential to promote cell apoptosis and cell cycle arrest. The inhibitory effect of celastrol on B16-F10 cells was further demonstrated by co-culturing with a PI3K activator. CONCLUSION: Celastrol inhibits the function of B16-F10 cells by inhibiting the PI3K/AKT/mTOR cellular pathway and regulating the expression of downstream HIF-α mRNA.

Chinese patent medicine combined with calcium channel blockers in the treatment of essential hypertension:a Bayes network meta-analysis and systematic review.

Backgroud: The co-administration of Chinese patent medicine with calcium channel blockers (CCBs) is a prevalent practice in China for treating essential hypertension (EH). However, robust evidence supporting the efficacy and safety of tailored combinations of different Chinese patent medicines with CCBs, according to individual patient conditions, is still limited. This study sought to elucidate the efficacy and safety of these combinations using a systematic review and network meta-analysis. Materials and methods: Relevant studies were sourced from established databases, incorporating randomized controlled trials published up to 1 February 2023. The ROB2 tool from the Cochrane Collaborative Network was employed to independently assess and cross-verify the quality of the included literature. A network meta-analysis was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) 2020 and PRISMA-Network Meta-Analyses (PRISMA-NMA) guidelines. A Bayesian network meta-analysis was utilized to gauge the efficacy and safety of distinct integrations of Chinese patent medicine and CCBs. Primary outcomes were interpreted using a paired fixed-effect meta-analysis. Publication bias was appraised through Egger's test and represented with funnel plots. All statistical analyses were executed within the R statistical framework. Results: Following rigorous selection, data extraction, and bias evaluation, 36 articles were incorporated. Tianma Gouteng Granule, when combined with CCBs, displayed superior efficacy in reducing systolic blood pressure (SBP). In terms of diastolic blood pressure (DBP) reduction, Songling Xuemaikang Capsule combined with CCBs emerged as the most effective. Regarding enhancement of antihypertensive effective rates, Qinggan Jiangya Capsule paired with CCBs demonstrated optimal results. For diminishing Traditional Chinese Medicine syndrome scores, the Qiangli Dingxuan Tablet and CCBs combination proved most beneficial. When aiming to reduce total cholesterol (TC), triglycerides (TG), and low-density lipoprotein cholesterol (LDL-C) levels, Tianma Gouteng Granule and CCBs showcased superior results. In contrast, the combination of Songling Xuemaikang Capsule and CCBs was more effective in reducing LDL-C, tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6). Conclusion: This study underscores variability in outcomes from combining Chinese patent medicine and CCBs for hypertension, emphasizing the importance of personalized medicinal combinations, especially Tianma Gouteng Granule and Songling Xuemaikang Capsule. The results offer robust evidence to inform clinical guidelines for essential hypertention and significantly aid clinician in seleting appropriate Chinese patent medicines for treatment.

Elucidating the anti-hypertensive mechanisms of Uncaria rhynchophylla-Alisma plantago-aquatica L: an integrated network pharmacology, cluster analysis, and molecular docking approach.

Background: With the increasing global prevalence of hypertension, a condition that can severely affect multiple organs, there is a growing need for effective treatment options. Uncaria rhynchophylla-Alisma plantago-aquatica L. (UR-AP) is a traditional drug pair used for treating hypertension based on the liver-kidney synergy concept. However, the detailed molecular mechanisms underlying its efficacy remain unclear. Methods: This study utilized an integrative approach combining network pharmacology, cluster analysis, and molecular docking to uncover the bioactive components and targets of UR-AP in the treatment of hypertension. Initially, we extracted data from public databases to identify these components and targets. A Protein-Protein Interaction (PPI) network was constructed, followed by enrichment analysis to pinpoint the bioactive components, core targets, and pivotal pathways. Cluster analysis helped in identifying key sub-networks and hypothesizing primary targets. Furthermore, molecular docking was conducted to validate the interaction between the core targets and major bioactive components, thus confirming their potential efficacy in hypertension treatment. Results: Network pharmacological analysis identified 58 bioactive compounds in UR-AP, notably quercetin, kaempferol, beta-sitosterol (from Uncaria rhynchophylla), and Alisol B, alisol B 23-acetate (from Alisma plantago-aquatica L.), as pivotal bioactives. We pinpointed 143 targets common to both UR-AP and hypertension, highlighting MAPK1, IL6, AKT1, VEGFA, EGFR, and TP53 as central targets involved in key pathways like diastolic and endothelial function, anti-atherosclerosis, AGE-RAGE signaling, and calcium signaling. Cluster analysis emphasized IL6, TNF, AKT1, and VEGFA's roles in atherosclerosis and inflammation. Molecular docking confirmed strong interactions between these targets and UR-AP's main bioactives, underscoring their therapeutic potential. Conclusion: This research delineates UR-AP's pharmacological profile in hypertension treatment, linking traditional medicine with modern pharmacology. It highlights key bioactive components and their interactions with principal targets, suggesting UR-AP's potential as a novel therapeutic option for hypertension. The evidence from molecular docking studies supports these interactions, indicating the relevance of these components in affecting hypertension pathways. However, the study acknowledges its limitations, including the reliance on in silico analyses and the need for in vivo validation. These findings pave the way for future clinical research, aiming to integrate traditional medicine insights with contemporary scientific approaches for developing innovative hypertension therapies.

A classic screening marker does not affect antennal electrophysiology but strongly regulates reproductive behaviours in Bactrocera dorsalis.

The key phenotype white eye (white) has been used for decades to selectively remove females before release in sterile insect technique programs and as an effective screening marker in genetic engineering. Bactrocera dorsalis is a representative tephritid pest causing damage to more than 150 fruit crops. Yet, the function of white in important biological processes remains unclear in B. dorsalis. In this study, the impacts of the white gene on electrophysiology and reproductive behaviour in B. dorsalis were tested. The results indicated that knocking out Bdwhite disrupted eye pigmentation in adults, consistent with previous reports. Bdwhite did not affect the antennal electrophysiology response to 63 chemical components with various structures. However, reproductive behaviours in both males and females were significantly reduced in Bdwhite-/- . Both pre-copulatory and copulation behaviours were significantly reduced in Bdwhite-/- , and the effect was male-specific. Mutant females significantly delayed their oviposition towards γ-octalactone, and the peak of oviposition behaviour towards orange juice was lost. These results show that Bdwhite might not be an ideal screening marker in functional gene research aiming to identify molecular targets for behaviour-modifying chemicals. Instead, owing to its strong effect on B. dorsalis sexual behaviours, the downstream genes regulated by Bdwhite or the genes from white-linked areas could be alternate molecular targets that promote the development of better behavioural modifying chemical-based pest management techniques.

Diagnosis, Treatment, and Management for Chronic Coronary Syndrome: A Systematic Review of Clinical Practice Guidelines and Consensus Statements.

Objectives: Management of chronic coronary syndrome (CCS) encompasses a broad spectrum of practices, posing considerable complexity and variability. While guidelines have been established to augment the management quality of CCS, notable disparities persist across their recommendations. This study strives to scrutinize, compare, and reconcile these guideline recommendations pertaining to the diagnosis, treatment, and management of CCS patients. Our goal is to align these recommendations with contemporary clinical practices, thus laying a robust foundation for their pragmatic application in clinical settings. Methods: A comprehensive systematic search was conducted across multiple databases, including PubMed, EMBASE, China National Knowledge Infrastructure, Wanfang Database, China Science and Technology Journal Database, Chinese Biomedical Literature Service System, Chinese Science and Technology Periodical Database, and Chinese Biological Medicine Database. The timeframe for this search spanned from their inception up to May 30, 2022, aiming to collate all published guidelines relevant to CCS. Subsequently, two independent reviewers undertook the task of appraising the quality of these guidelines by utilizing the Appraisal of Guidelines for Research and Evaluation II instrument. Results: The search yielded a total of 10,699 citations. Following a thorough evaluation, fourteen clinical practice guidelines and four consensus statements, each offering specific recommendations for CCS, were selected. The quality of these guidelines showcased a broad spectrum of variation. The domain of "presentation clarity" received the highest accolades, while "applicability" languished at the lower end of the scoring spectrum. On average, the guidelines attained a quality score denoting sufficiency. Furthermore, recommendations across different guidelines for the diagnosis, treatment, and management of CCS displayed a striking level of divergence. Conclusion: The landscape of published CCS guidelines is marked by extensive variations in scope, quality, and recommendations. Hence, there is a compelling need for collaborative efforts amongst multidisciplinary professionals to forge comprehensive, higher-quality evidence-based guidelines; such a concerted approach is paramount to enhance treatment efficacy and health outcomes for patients grappling with CCS.

Research on the sustainable development of tourism coupled with economic and environment data--a case study of Hangzhou.

The scale of tourism has continued to expand in recent years, and many associated activities cause damage to the natural environment. The tourism, economy and natural environment constitute a system: destruction of the natural environment reduces the value of tourism and a lack of tourism affects the development of the economy. To explore the relationship between the tourism, economy and natural environment, and to explore possibilities for sustainable development, this paper takes Hangzhou, a tourist city in China, as a research object. An analysis of time series data is carried out. First, the tourism, economy and natural environment subsystems are constructed by extracting time series data acquired between 2010 and 2020. Second, a tourism evaluation model with coupled economic and natural environment data is constructed and the coupling degree and coupling coordination level in Hangzhou are evaluated. Third, the time series of each subsystem and the coupling coordination level of the whole system are analyzed. Finally, an optimization strategy is proposed for the coupled coordinated development of the tourism, economy and natural environment in Hangzhou. A key result is that the tertiary industry represented by tourism has become the main source of local income. Hangzhou's tourism coupling coordination level has changed from slight disorder in 2010 to good in 2020. It is also found that the COVID-19 pandemic has become a major factor restricting the development of tourism. Before the outbreak of COVID-19, Hangzhou's tourism industry and economy were synchronized. After the outbreak of COVID-19, both the number of tourists and tourism revenue in Hangzhou fell by nearly 15%.

Endogenous endophthalmitis caused by urinary tract infection: A case report.

RATIONALE: Endogenous endophthalmitis is a vision-threatening intraocular infection caused by hematogenous spread of infectious organisms from distant sites. PATIENT CONCERNS: A 71-year-old man with a history of fever and dysuria 5 days prior to presentation presented with sudden loss of vision in his left eye. The patient had no history of ocular surgery or trauma, and ocular examination revealed a large amount of exudative plaque covering the pupil. Therefore, fundus examination was not feasible. B-scan ultrasonography revealed a dome-shaped subretinal mass with an exudative retinal detachment. DIAGNOSIS: Endogenous endophthalmitis was diagnosed on the basis of these findings. INTERVENTIONS: The patient underwent pars plana vitrectomy and the early postoperative course was favorable. OUTCOMES: Vitreous cultures grew gram-negative bacilli, identified as Klebsiella pneumonia. Urinalysis revealed white blood cells (++) and urinary tract infection was the only identifiable risk factor for endogenous endophthalmitis. LESSONS: Urinary tract infection is an independent risk factor for endogenous endophthalmitis.

Therapeutic applications of contact lens-based drug delivery systems in ophthalmic diseases.

Traditional ophthalmic drugs, such as eye drops, gels and ointments, are accompanied by many problems, including low bioavailability and potential drug side effects. Innovative ophthalmic drug delivery systems have been proposed to overcome the limitations associated with traditional formulations. Recently, contact lens-based drug delivery systems have gained popularity owing to their advantages of sustained drug delivery, prolonged drug retention, improved bioavailability, and few drug side effects. Various methods have been successfully applied to drug-loaded contact lenses and prolonged the drug release time, such as chemical crosslinking, material embedding, molecular imprinting, colloidal nanoparticles, vitamin E modification, drug polymer film/coating, ion ligand polymerization systems, and supercritical fluid technology. Contact lens-based drug delivery systems play an important role in the treatment of multifarious ophthalmic diseases. This review discusses the latest developments in drug-loaded contact lenses for the treatment of ophthalmic diseases, including preparation methods, application in ophthalmic diseases and future prospects.

Electroenzymatic Reduction of Furfural to Furfuryl Alcohol by an Electron Mediator and Enzyme Orderly Assembled Biocathode.

The electroenzymatic valorization of biomass derivatives into valuable biochemicals has a promising outlook. However, bottlenecks including poor electron transfer between the electrode surface and oxidoreductase, inefficient regeneration of cofactors, and high cost of enzymes and electron mediators hindered the realistic applications of the technique. Herein, to address the above technical barriers, a novel bio-electrocatalytic system that integrates the electrochemical NADH regeneration and enzymatic reaction was constructed, using an orderly assembled composite bioelectrode consisting of an outer immobilized enzyme layer and a sandwiched redox mediator rhodium complex layer. The as-prepared composite bioelectrode was further applied for the highly selective hydrogenation of furfural into furfural alcohol. Results indicated that the enzyme activity was significantly improved, while the furfural valorization was promoted by effective interfacial electron transition and co-factor regeneration on the composite bioelectrode. Considerable high furfural conversion (96.4%) can be achieved accompanied by a furfural alcohol selectivity of 90.0% at -1.2 V (vs Ag/AgCl). The novel composite bioelectrode also showed good stability and reusability. Up to 85.1% of the original furfural alcohol selectivity can be preserved after 10 times of recycling. This work presents a promising green alternative for the valorization of furfural, which also shows great potential extending to the valorization of other biomass compounds.

Rare short- and medium-chain fatty acid-producing anaerobes from raw soil play vital roles in formation of diverse flavour compounds of Jiangxiangxing Baijiu.

Pit mud is an essential habitat for diverse anaerobes, however, how pit mud of Jiangxiangxing Baijiu contributes to flavour is still unclear. The correlation between pit mud anaerobes and flavour compounds formation was investigated by analyzing flavour compounds and prokaryotic community of pit mud as well as fermented grains. Then scaling-down fermentation and culture-dependent approach were used to verify the effects of pit mud anaerobes on flavour compound formation. We found that short- and medium-chain fatty acids and alcohols, e.g., propionate, butyrate, caproate, 1-butanol, 1-hexanol, and 1-heptanol, were the vital flavour compounds produced by pit mud anaerobes. Pit mud anaerobes hardly migrated into fermented grains because of the low pH and low moisture of fermented grains. Therefore, the flavour compounds produced by pit mud anaerobes might enter fermented grains via volatilization. Moreover, enrichment culturing proved that raw soil was one of the sources for pit mud anaerobes, e.g., Clostridiumtyrobutyricum, Ruminococcaceae bacterium BL-4 and Caproicibacteriumamylolyticum. These rare short- and medium-chain fatty acid-producing anaerobes in raw soil can be enriched during Jiangxiangxing Baijiu fermentation. These findings clarified the role of pit mud during Jiangxiangxing Baijiu fermentation and revealed the key species involved in short- and medium-chain fatty acid-producing production.

The age-related metabolizable energy of cereal grains, oilseed meals, corn gluten meals, and feather meals for broilers.

A 2 × 3 factorial arrangement of treatments with two ages of broilers (11 to 14 or 25 to 28 d of age) and three samples of feed ingredients was utilized to compare metabolizable energy (ME) and ratio of ME to gross energy (GE) in each group of three cereal grains (CG, including one corn, two wheat flour), three oilseed meals (OM, including one soybean meal, one peanut meal, and one cottonseed meal), three corn gluten meals (CGM A, B, and C), and three feather meals (FM A, B, and C). Each treatment contained six replicates of four Arbor Acre male broilers in energy balance experiments. Trends toward interactions between age and source of CG were observed on the ME and ME/GE of CG (0.05

Databases lack true information on metabolizable energy (ME) values of feed ingredients for broilers across phases. The current study evaluated the effect of broiler age (11 to 14 d or 25 to 28 d) on ME of three cereal grains (CG, one corn, two wheat flour [WF]), three oilseed meals (OM, one soybean meal, one peanut meal, and one cottonseed meal), three corn gluten meals (CGM, three sources of CGM differed in crude protein content), and three feather meals (FM, one enzymatical hydrolyzed FM, one expanded FM, and one hydrolyzed FM). Our study demonstrated no interactive effects between broiler age and source of feed on ME of OM and FM, but detected interactive effects for CG and CGM. Thus, the effect of age on ME can depend on the type of feed and its chemical composition. In addition, the ME of WF and OM was not affected by age, but the ME of corn, CGM, and FM increased as broilers aged. These results indicate that the ME in starter diets with corn, CGM, and FM may be overestimated if the ME values of feed ingredients are obtained from growing broilers.

[Clinical application of targeted sealing with high viscosity bone cement and secondary injection of low viscosity bone cement in vertebroplasty].

OBJECTIVE: To observe the clinical efficacy of targeted sealing with high viscosity bone cement and secondary injection of low viscosity bone cement in the treatment of OVCFs patients with the fracture lines involved vertebral body margin. METHODS: The elderly patients who underwent vertebroplasty for osteoporotic vertebral compression fractures from January 2019 to September 2021 were selected as the screening objects. Through relevant standards and further CT examination, 56 patients with fracture lines involving the anterior wall or upper and lower endplates of the vertebral body were selected for the study. There were 21 males and 35 females, aged from 67 to 89 years old with an average of (76.58±9.68) years. All 56 patients underwent secondary injection of bone cement during operation. Only a small amount of high viscosity cement was targeted to seal the edge of the vertebral body for the first time, and low viscosity cement was injected to the vertebral bodies during second bolus with well-distributed. The operation time, bone cement volume and bone cement leakage were recorded, and the pain relief was evaluated by visual analogue scale (VAS). RESULTS: All patients were followed up for more than 3 months and the surgeries were successfully complete. The operation time was (50.41±10.30) min and the bone cement volume was (3.64±1.29) ml. The preoperative VAS was (7.21±2.41) points, which decreased significantly to (2.81±0.97) points 3 days after operation(P<0.05). Among the 56 patients, 2 cases(3.57%) had bone cement leakage, 1 case leaked to the paravertebral vein, and 1 case slightly bulged to the paravertebral through the crack when plugging the vertebral crack. Both patients had no obvious clinical symptoms. CONCLUSION: In vertebroplasty surgery, targeted sealing of high viscosity bone cement and secondary injection of low viscosity bone cement can reduce intraoperative bone cement leakage and improve the safety of operation.

Quantitative Evaluation of Binocular Visual Perception in Patients With Strabismus: An Observational Study.

PURPOSE: To quantitatively evaluate and compare binocular visual perception between normal individuals and patients with different types of strabismus using a binocular phase combination paradigm. METHODS: A total of 117 participants were included in the study and were divided into the normal control group, exophoria group, comitant exotropia group, comitant esotropia group, and special strabismus group according to the type of strabismus. The effective contrast ratio (ECR) was measured to quantitatively evaluate binocular visual perception. Binocular fusion was evaluated using the Worth 4-dots flashlight. Stereoacuity was detected by the Titmus stereo test. RESULTS: The mean ECRs in the normal control group, exophoria group, comitant exotropia group, comitant esotropia group, and special strabismus group were 0.896 ± 0.214, 0.824 ± 0.234, 0.520 ± 0.279, 0.261 ± 0.139, and 0.461 ± 0.243, respectively. Within-group differences in the ECR were statistically significant. In addition, there was no statistically significant difference between the normal control group and exophoria group, and the concomitant exotropia group and special strabismus group and the other groups were statistically significant in pairwise comparison. The binocular visual perception was basically balanced in the exotropia group and most imbalanced in the comitant esotropia group, followed by the comitant exotropia group and the special strabismus group. The results also indicated that the decreased ECR was related to poor stereopsis and ECR had a significant positive correlation with binocular fusion function. CONCLUSIONS: Different types of strabismus have different degrees of visual perception imbalance. The binocular phase combination paradigm applied in this study can quickly and accurately quantify the degree of binocular visual perception imbalance in patients with strabismus by measuring ECR. [J Pediatr Ophthalmol Strabismus. 2023;60(2):120-130.].

Prediction for optimal dosage of pazopanib under various clinical situations using physiologically based pharmacokinetic modeling.

This study aimed to apply a physiologically based pharmacokinetic (PBPK) model to predict optimal dosing regimens of pazopanib (PAZ) for safe and effective administration when co-administered with CYP3A4 inhibitors, acid-reducing agents, food, and administered in patients with hepatic impairment. Here, we have successfully developed the population PBPK model and the predicted PK variables by this model matched well with the clinically observed data. Most ratios of prediction to observation were between 0.5 and 2.0. Suitable dosage modifications of PAZ have been identified using the PBPK simulations in various situations, i.e., 200 mg once daily (OD) or 100 mg twice daily (BID) when co-administered with the two CYP3A4 inhibitors, 200 mg BID when simultaneously administered with food or 800 mg OD when avoiding food uptake simultaneously. Additionally, the PBPK model also suggested that dosing does not need to be adjusted when co-administered with esomeprazole and administration in patients with wild hepatic impairment. Furthermore, the PBPK model also suggested that PAZ is not recommended to be administered in patients with severe hepatic impairment. In summary, the present PBPK model can determine the optimal dosing adjustment recommendations in multiple clinical uses, which cannot be achieved by only focusing on AUC linear change of PK.

Revealing the Characteristics of Glucose- and Lactate-Based Chain Elongation for Caproate Production by Caproicibacterium lactatifermentans through Transcriptomic, Bioenergetic, and Regulatory Analyses.

Caproate, an important medium-chain fatty acid, can only be synthesized by limited bacterial species by using ethanol, lactate, or certain saccharides. Caproicibacterium lactatifermentans is a promising caproate producer due to its glucose and lactate utilization capabilities. However, the global cellular responses of this bacterium to different carbon sources were not well understood. Here, C. lactatifermentans showed robust growth on glucose but more active caproate synthesis on lactate. Comparative transcriptome revealed that the genes involved in reverse ß-oxidation for caproate synthesis and V-type ATPase-dependent ATP generation were upregulated under lactate condition, while several genes responsible for biomass synthesis were upregulated under glucose condition. Based on metabolic pathway reconstructions and bioenergetics analysis, the biomass accumulation on glucose condition may be supported by sufficient supplies of ATP and metabolite intermediates via glycolysis. In contrast, the ATP yield per glucose equivalent from lactate conversion into caproate was only 20% of that from glucose. Thus, the upregulation of the reverse ß-oxidation genes may be essential for cell survival under lactate conditions. Furthermore, the remarkably decreased lactate utilization was observed after glucose acclimatization, indicating the negative modulation of lactate utilization by glucose metabolism. Based on the cotranscription of the lactate utilization repressor gene lldR with sugar-specific PTS genes and the opposite expression patterns of lldR and lactate utilization genes, a novel regulatory mechanism of glucose-repressed lactate utilization mediated via lldR was proposed. The results of this study suggested the molecular mechanism underlying differential physiologic and metabolic characteristics of C. lactatifermentans grown on glucose and lactate. IMPORTANCE Caproicibacterium lactatifermentans is a unique and robust caproate-producing bacterium in the family Oscillospiraceae due to its lactate utilization capability, whereas its close relatives such as Caproicibacterium amylolyticum, Caproiciproducens galactitolivorans, and Caproicibacter fermentans cannot utilize lactate but produce lactate as the main fermentation end product. Moreover, C. lactatifermentans can also utilize several saccharides such as glucose and maltose. Although the metabolic versatility of the bacterium makes it to be a promising industrial caproate producer, the cellular responses of C. lactatifermentans to different carbon sources were unknown. Here, the molecular mechanisms of biomass synthesis supported by glucose utilization and the cell survival supported by lactate utilization were revealed. A novel insight into the regulatory machinery in which glucose negatively regulates lactate utilization was proposed. This study provides a valuable basis to control and optimize caproate production, which will contribute to achieving a circular economy and environmental sustainability.

Constructing simplified microbial consortia to improve the key flavour compounds during strong aroma-type Baijiu fermentation.

The ester compounds play key roles in maintaining the sensory characteristics of alcoholic beverages. For strong aroma-type Baijiu fermentation, the volatile acids from pit mud microbes are key precursors for ester synthesis. However, the volatile acids can only be efficiently synthesized by the pit mud microbes in grains which attaches to pit mud. Elevating the ester contents in the upper layer's fermented grains is vital to improve the quality of raw liquor. In this study, we applied top-down strategy and aim to simplify and obtain pit mud microbial consortia to efficiently produce caproate but not off-flavour compounds. The simplified consortia with Caproiciproducens spp. as dominant species can use unsterilized fermentation water as sole substrate for caproate production, and stable caproate production was achieved by inoculating these simplified consortia in scaling-up fermentation. The fermented broth was then applied to facilitate the fermentation of upper layer's grains to prompt ester synthesis. Finally, the contents of variety esters such as ethyl caproate, ethyl pentanoate and ethyl octanoate were markedly increased. Together, this study demonstrates that constructing simplified microbial consortia containing key flavour-producing species is feasible to improve the flavour quality of spontaneously fermented foods.

Mutual Conversion of CO-CO2 on a Perovskite Fuel Electrode with Endogenous Alloy Nanoparticles for Reversible Solid Oxide Cells.

Reversible solid oxide cells (RSOCs) can efficiently render the mutual conversion between electricity and chemicals, for example, electrolyzing CO2 to CO under a solid oxide electrolysis cell (SOEC) mode and oxidizing CO to CO2 under a solid oxide fuel cell (SOFC) mode. Nevertheless, the development of RSOCs is still hindered, owing to the lack of catalytically active and carbon-tolerant fuel electrodes. For improving mutual CO-CO2 conversion kinetics in RSOCs, here, we demonstrate a high-performing and durable fuel electrode consisting of redox-stable Sr2(Fe, Mo)2O6-δ perovskite oxide and epitaxially endogenous NiFe alloy nanoparticles. The electrochemical impedance spectrum (EIS) and distribution of relaxation time (DRT) analyses reveal that surface/interface oxygen exchange kinetics and the CO/CO2 activation process are both greatly accelerated. The assembled single cell produces a maximum power density (MPD) of 443 mW cm-2 at 800 °C under the SOFC mode, with the corresponding CO oxidation rate of 5.524 mL min-1 cm-2. On the other hand, a current density of -0.877 A cm-2 is achieved at 1.46 V under the SOEC mode, equivalent to a CO2 reduction rate of 6.108 mL min cm-2. Furthermore, reliable reversible conversion of CO-CO2 is proven with no performance degradation in 20 cycles under SOEC (1.3 V) and SOFC (0.6 V) modes. Therefore, our work provides an alternative way for designing highly active and durable fuel electrodes for RSOC applications.

Caproicibacterium lactatifermentans sp. nov., isolated from pit clay used for the production of Chinese strong aroma-type liquor.

Two recently reported bacterial strains that were identified as the dominant caproate-producing bacteria in pit clay, were further characterized to determine their phylogeny and taxonomy. The two strains, designated as LBM19010T and JNU-WLY1368, were short rod-shaped, Gram-stain-positive, non-motile and strictly anaerobic. Analysis of the 16S rRNA gene sequences revealed that strains LBM19010T and JNU-WLY1368 shared a 16S rRNA gene sequence similarity of 99.93 % and belonged to a recent proposed genus Caproicibacterium in the family Oscillospiraceae. The proposed type strain, LBM19010T, showed the highest 16S rRNA gene sequence similarity to Caproicibacterium amylolyticum LBM18003T (96.34%), followed by Caproiciproducens galactitolivorans JCM 30532T (94.14 %). The pairwise average nucleotide identity and average amino acid identity values between strains LBM19010T and LBM18003T were 74.84 and 76.18 %, respectively. Growth of strain LBM19010T occurred at pH 4.5-7.5 (optimum, pH 5.0-5.5), 20-40 °C (optimum, 35 °C) and with 0-1 % (w/v) NaCl (optimum, 0 %). Strains LBM19010T and JNU-WLY1368 were both able to ferment several hexoses, disaccharides, starch and lactate but not pentoses. Caproate and butyrate were the major end-products from glucose. The predominant cellular fatty acids (>10 %) of strain LBM19010T were C16 : 0 (56.3 %), C14 : 0 DMA (19.5 %) and C14 : 0 (14.9 %). The identified polar lipids of strain LBM19010T were diphosphatidylglycerol, phosphatidylglycerol, three unidentified phospholipids and nine unidentified glycolipids. Based on phylogenetic, phenotypic and chemotaxonomic evidence, strains LBM19010T and JNU-WLY1368 belong to a novel species of the genus Caproicibacterium, for which the name Caproicibacterium lactatifermentans sp. nov. is proposed. The type strain is LBM19010T (=GDMCC 1.1627T=JCM 33782T).

Proteiniphilum propionicum sp. nov., a novel member of the phylum Bacteroidota isolated from pit clay used to produce Chinese liquor.

A novel, Gram-stain-negative, rod-shaped, strictly anaerobic bacterium of genus Proteiniphilum of the phylum Bacteroidota, named strain JNU-WLY501T, was isolated from pit clay used to produce strong aroma-type liquor in PR China. The genomic DNA G+C content and genome size of JNU-WLY501T were 41.4 % and 3.9 Mbp, respectively. The results of phylogenetic analysis based on 16S rRNA gene sequences indicated that JNU-WLY501T was closely related to Proteiniphilum acetatigenes DSM 18083T (95.7 %) and Proteiniphilum saccharofermentans M3/6T (94.9 %). The pairwise average nucleotide identity based on blast and average amino acid identity values of JNU-WLY501T compared with Proteiniphilum saccharofermentans M3/6T were 73.6 and 77.3 %, respectively, which both were lower than the threshold values for bacterial species delineation. The strain grew at 20-40 °C, with optimum growth at 37 °C. The pH range for growth was 5.4-9.1, with optimum growth at pH 7.5. The sodium chloride range for growth was 0.0-4.0 %, with optimum growth at 0 %. The strain did not use glucose, maltose, fructose or starch. Yeast extract, tryptone and peptone supported the growth of JNU-WLY501T, and the main fermentation products were acetate and propionate. The predominant cellular fatty acids (>5 %) of JNU-WLY501T were anteiso-C15 : 0 (30.6 %), anteiso-C17 : 0 (26.1 %), C16 : 0 (7.7 %), iso-C16 : 0 (5.0 %) and iso-C17 : 0 (5.0 %). The respiratory quinone of JNU-WLY501T was MK-5. On the basis of the morphological, physiological, biochemical, chemotaxonomic, genotypic and phylogenetic results, JNU-WLY501T represents a novel species of the genus Proteiniphilum, for which the name Proteiniphilum propionicum sp. nov. is proposed. The type strain is JNU-WLY501T (=GDMCC 1.2686T=JCM 34753T).

Adaptability of a Caproate-Producing Bacterium Contributes to Its Dominance in an Anaerobic Fermentation System.

The transformation of diverse feedstocks into medium-chain fatty acids (MCFAs) by mixed cultures is a promising biorefinery route because of the high value of MCFAs. A particular concern is how to maintain the microbial consortia in mixed cultures to achieve stable MCFA production. The Chinese strong aroma-type liquor (Baijiu) fermentation system continually produces caproic acid for decades through a spontaneous inoculation of anaerobes from pit mud into fermented grains. Therefore, illuminating the dominant caproate-producing bacterium (CPB) in pit mud and how the CPB is sustained in the spontaneous fermentation system will help to reveal the microbiological mechanisms of stable caproate production. Here, we examined pit mud samples across four Chinese strong aroma-type Baijiu-producing areas and found that a caproate-producing Caproicibacterium sp. was widely distributed in these distilleries, with relative abundance ranging from 1.4 to 35.5% and an average abundance of 11.4%. Through controlling carbon source availability, we obtained different simplified caproate-producing consortia and found that the growth advantage of Caproicibacterium sp. was highly dependent on glucose. Then, two strains, named Caproicibacterium sp. strain LBM19010 and Caproicibacterium sp. strain JNU-WLY1368, were isolated from pit mud of two regions. The metabolic versatility of this species utilizing starch, maltose, glucose, and lactate reflected its adaptability to the fermentation environment where these carbon sources coexist. The simultaneous utilization of glucose and lactate contributed to the balance between cell growth and pH homeostasis. This study reveals that multiple adaptation strategies employed by the predominant CPB promotes its stability and dominance in a saccharide- and lactate-rich anaerobic habitat. IMPORTANCE The Chinese strong aroma-type liquor (Baijiu) fermentation environment is a typical medium-chain fatty acid-producing system with complex nutrients. Although several studies have revealed the correlation between microbial community composition and abiotic factors, the adaptation mechanisms of dominant species to abiotic environment are still unknown in this special anaerobic habitat. This study identified the predominant CPB in Chinese strong aroma-type Baijiu fermentation system. Metabolic versatility and flexibility of the dominant CPB with a small-size genome indicated that this bacterium can effectively exploit available carbon and nitrogen sources, which could be a key factor to promote its ecological success in a multispecies environment. The understanding of growth and metabolic features of the CPB responsible for its dominance in microbial community will not only contribute to the improvement of Chinese strong aroma-type Baijiu production but also expand its potential industrial applications in caproate production.