Important Metabolites Research Articles

HEAT STRESS IN CITRUS: A MOLECULAR FUNCTIONAL AND BIOCHEMICAL PERCEPTION

Misfortunes caused by high temperatures compel us to more readily comprehend the physiological, hormonal, and sub-atomic systems of reactions, particularly in humid and subhumid yields such as citrus organic products that are accustomed to specific conditions. Heat stress is accustomed to drought and many other environmental factors affecting Citriculture. We observe the role of Rubisco, antioxidant enzymes, HSPs, physiological changes in plasma membranes, and the role of ABA and SA under heat stress in citrus. Not-with-standing essential exploration, developing and utilizing new and well-developed citrus rootstocks is an essential element for the regulation, according to ecological circumstances. Rootstocks are essential in controlling how plants react to changing environmental factors, such as heat stress. They transfer beneficial features and increase stress tolerance, which helps citrus plants be more resilient overall. The duration of growth, yield, fruit quality, and tolerance to biotic and abiotic challenges are only a few of the characteristics of citrus horticulture that can be significantly improved using the right rootstocks. Enhancing citrus fruits' resistance to unfavorable environmental circumstances is urgently needed due to climate change. We can learn more about how different rootstocks affect the scion's capacity to withstand abiotic pressures by examining the metabolic responses caused by those rootstocks. Because of its increased antioxidant capacity, improved stomatal control, and storage of protective proteins, Carrizo citrange, for instance, demonstrates superior resilience to heat stress when compared to Cleopatra mandarin. The combined impacts of heat and drought on citrus vegetation differ from the effects of each stress alone. Specific metabolic changes are occur, which agree with findings from other plant research looking at the combined impacts of stress on physiology, transcriptome, proteome, and metabolome. When using rootstocks like Sunki Maravilha mandarin under drought stress, important metabolites such as galactinol, raffinose, and SA can be enhanced in scions through grafting. On the other hand, the Cleopatra rootstock alters the metabolism of the scion, resulting in lower quantities of the amino acids galactinol, raffinose, proline, phenylalanine, and tryptophan, which could lead to undesired characteristics. These results highlight the value of continued research to solve the problems brought on by climate change and provide light on the role of rootstocks in citriculture.

Research overview on the genetic mechanism underlying the biosynthesis of polysaccharide in tuber plants.

Tuber plants are of great significance in the world as human food crops. Polysaccharides, important metabolites in tuber plants, also serve as a source of innovative drugs with significant pharmacological effects. These drugs are particularly known for their immunomodulation and antitumor properties. To fully exploit the potential value of tuber plant polysaccharides and establish a synthetic system for their targeted synthesis, it is crucial to dissect their metabolic processes and genetic regulatory mechanisms. In this article, we provide a comprehensive summary of the basic pathways involved in the synthesis of various types of tuber plant polysaccharides. We also outline the key research progress that has been made in this area in recent years. We classify the main types and functions of tuber plant polysaccharides and analyze the biosynthetic processes and genetic regulation mechanisms of key enzymes involved in the metabolic pathways of starch, cellulose, pectin, and fructan in tuber plants. We have identified hexokinase and glycosyltransferase as the key enzymes involved in the polysaccharide synthesis process. By elucidating the synthesis pathway of polysaccharides in tuber plants and understanding the underlying mechanism of action of key enzymes in the metabolic pathway, we can provide a theoretical framework for enhancing the yield of polysaccharides and other metabolites in plant culture cells. This will ultimately lead to increased production efficiency.

GBF family member PfGBF3 and NAC family member PfNAC2 regulate rosmarinic acid biosynthesis under high light.

Rosmarinic acid (RA) is an important medicinal metabolite and a potent food antioxidant. We discovered that exposure to high light intensifies the accumulation of RA in the leaves of perilla (Perilla frutescens (L.) Britt). However, the molecular mechanism underlying RA synthesis in response to high light stress remains poorly understood. To address this knowledge gap, we conducted a comprehensive analysis employing transcriptomic sequencing, transcriptional activation, and genetic transformation techniques. High light treatment for 1 and 48 h resulted in the upregulation of 592 and 1,060 genes, respectively. Among these genes, three structural genes and 93 transcription factors exhibited co-expression. Notably, NAC family member PfNAC2, GBF family member PfGBF3, and cinnamate-4-hydroxylase gene PfC4H demonstrated significant co-expression and upregulation under high light stress. Transcriptional activation analysis revealed that PfGBF3 binds to and activates the PfNAC2 promoter. Additionally, both PfNAC2 and PfGBF3 bind to the PfC4H promoter, thereby positively regulating PfC4H expression. Transient overexpression of PfNAC2, PfGBF3, and PfC4H, as well as stable transgenic expression of PfNAC2, led to a substantial increase in RA accumulation in perilla. Consequently, PfGBF3 acts as a photosensitive factor that positively regulates PfNAC2 and PfC4H, while PfNAC2 also regulates PfC4H to promote RA accumulation under high light stress. The elucidation of the regulatory mechanism governing RA accumulation in perilla under high light conditions provides a foundation for developing a high-yield RA system and a model to understand light-induced metabolic accumulation.

In vitro biological control of Pyrrhoderma noxium using volatile compounds produced by termite gut-associated streptomycetes.

Pyrrhoderma noxium is a plant pathogen that causes economic losses in agricultural and forestry industries, including significant destruction to amenity trees within the city of Brisbane in Australia. Use of chemical control agents are restricted in public areas, there is therefore an urgent need to investigate biological control approaches. Members of the phylum Actinomycetota, commonly known as actinomycetes, are known for their industrially important secondary metabolites including antifungal agents. They have proven to be ideal candidates to produce environmentally friendly compounds including the volatile organic compounds (VOCs) which can be used as biofumigants. Different Streptomyces species (n=15) previously isolated from the guts of termites and stored in the University of the Sunshine Coast'sMicrobial Library were tested for their antifungal VOCs against Pyrrhoderma noxium. Fourteen of them were found to display inhibition (39.39-100%) to the mycelial development of the pathogen. Strongest antifungal activity displaying isolates USC-592, USC-595, USC-6910 and USC-6928 against the pathogen were selected for further investigations. Their VOCs were also found to have plant growth promotional activity observed for Arabidopsis thaliana with an increase of root length (22-36%) and shoot length (26-57%). The chlorophyll content of the test plant had a slight increase of 11.8% as well. Identified VOCs included geosmin, 2-methylisoborneol, 2-methylbutyrate, methylene cyclopentane, β-pinene, dimethyl disulfide, ethyl isovalerate, methoxyphenyl-oxime and α-pinene. Additionally, all 15 Streptomyces isolates were found to produce siderophores and indole acetic acid as well as the enzyme chitinase which is known to break down the fungal cell wall. Findings indicate that termite gut-associated streptomycetes might be used to control Pyrrhoderma noxium by utilizing their wide range of inhibitory mechanisms.

The Ginkgo biloba microRNA160-ERF4 module participates in terpene trilactone biosynthesis.

Terpene trilactones (TTLs) are important secondary metabolites in ginkgo (Ginkgo biloba); however, their biosynthesis gene regulatory network remains unclear. Here, we isolated a G. biloba ethylene response factors 4 (GbERF4) involved in TTL synthesis. Overexpression of GbERF4 in tobacco (Nicotiana tabacum) significantly increased terpenoid content and upregulated the expression of key enzyme genes (3-hydroxy-3-methylglutaryl-CoA reductase (HMGR), 3-hydroxy-3-methylglutaryl-CoA synthase (HMGS), 1-deoxy-D-xylulose-5-phosphate reductoisomerase (DXR), 1-deoxy-D-xylulose-5-phosphate synthase (DXS), acetyl-CoA C-acetyltransferase (AACT), and geranylgeranyl diphosphate synthase (GGPPS)) in the terpenoid pathway in tobacco, suggesting that GbERF4 functions in regulating the synthesis of terpenoids. The expression pattern analysis and previous microRNA (miRNA) sequencing showed that gb-miR160 negatively regulates the biosynthesis of TTLs. Transgenic experiments showed that overexpression of gb-miR160 could significantly inhibit the accumulation of terpenoids in tobacco. Targeted inhibition and dual-luciferase reporter assays confirmed that gb-miR160 targets and negatively regulates GbERF4. Transient overexpression of GbERF4 increased TTL content in G. biloba, and further transcriptome analysis revealed that DXS, HMGS, CYPs, and transcription factor genes were upregulated. In addition, yeast one-hybrid and dual-luciferase reporter assays showed that GbERF4 could bind to the promoters of the HMGS1, AACT1, DXS1, levopimaradiene synthase (LPS2), and GGPPS2 genes in the TTL biosynthesis pathway and activate their expression. In summary, this study investigated the molecular mechanism of the gb-miR160-GbERF4 regulatory module in regulating the synthesis of TTLs. It provides information for enriching the understanding of the regulatory network of TTL biosynthesis and offers important gene resources for the genetic improvement of G. biloba with high contents of TTLs.

Metabolomic landscape of overall and common cancers in the UK Biobank: A prospective cohort study.

Information about the NMR metabolomics landscape of overall, and common cancers is still limited. Based on a cohort of 83,290 participants from the UK Biobank, we used multivariate Cox regression to assess the associations between each of the 168 metabolites with the risks of overall cancer and 20 specific types of cancer.Then, we applied LASSO to identify important metabolites for overall cancer risk and obtained their associations using multivariate cox regression. We further conducted mediation analysis to evaluate the mediated role of metabolites in the effects of traditional factors on overall cancer risk. Finally, we included the 13 identified metabolites as predictors in prediction models, and compared the accuracies of our traditional models. We found that there were commonalities among the metabolic profiles of overall and specific types of cancer: the top 20 frequently identified metabolites for 20 specific types of cancer were all associated with overall cancer; most of the specific types of cancer had common identified metabolites. Meanwhile, the associations between the same metabolite with different types of cancer can vary based on the site of origin. We identified 13 metabolic biomarkers associated with overall cancer, and found that they mediated the effects of traditional factors. The accuracies of prediction models improved when we added 13 identified metabolites in models. This study is helpful to understand the metabolic mechanisms of overall and a wide range of cancers, and our results also indicate that NMR metabolites are potential biomarkers in cancer diagnosis and prevention.

Biotechnological approaches for the production of hypericin and other important metabolites from the genus Hypericum

Biotechnological approaches for the production of hypericin and other important metabolites from the genus Hypericum

Evaluating the multiple sulfur isotope signature of Eoarchean rocks from the Isua Supracrustal Belt (Southwest-Greenland) by MC-ICP-MS: Volcanic nutrient sources for early life.

On the anoxic Archean Earth, prior to the onset of oxidative weathering, electron acceptors were relatively scarce, perhaps limiting microbial productivity. An important metabolite may have been sulfate produced during the photolysis of volcanogenic SO2 gas. Multiple sulfur isotope data can be used to track this sulfur source, and indeed this record indicates SO2 photolysis dating back to at least 3.7 Ga, that is, as far back as proposed evidence of life on Earth. However, measurements of multiple sulfur isotopes in some key strata from that time can be challenging due to low sulfur concentrations. Some studies have overcome this challenge with NanoSIMS or optimized gas-source mass spectrometry techniques, but those instruments are not readily accessible. Here, we applied an aqua regia leaching protocol to extract small amounts of sulfur from whole rocks for analyses of multiple sulfur isotopes by multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). Measurements of standards and replicates demonstrate good precision and accuracy. We applied this technique to meta-sedimentary rocks with putative biosignatures from the Eoarchean Isua Supracrustal Belt (ISB, >3.7 Ga) and found positive ∆33S (1.40-1.80‰) in four meta-turbidites and negative ∆33S (-0.80‰ and -0.66‰) in two meta-carbonates. Two meta-basalts do not display significant mass-independent fractionation (MIF, -0.01‰ and 0.16‰). Insitu Re-Os dating on a molybdenite vein hosted in the meta-turbidites identifies an early ca. 3.7 Ga hydrothermal phase, and insitu Rb-Sr dating of micas in the meta-carbonates suggests metamorphism affected the rocks at ca. 2.2 and 1.7 Ga. We discuss alteration mechanisms and conclude that there is most likely a primary MIF-bearing phase in these meta-sediments. Our new method is therefore a useful addition to the geochemical toolbox, and it confirms that organisms at that time, if present, may indeed have been fed by volcanic nutrients.

Recent Developments and Future Prospects of Natural Antimicrobial Bioactive Metabolites Obtained from Endophytic Bacterial Isolate

Background: Adathoda beddomei (Adosa), a kind of softwood, evergreen, perennial shrub, has been used as a source of endophyte bacteria. Adhatoda beddomei has a wide variety of chemicals, including anthocyanins, aminophylline, alkaloids, cardiac glycosides, isoprenaline, triterpenoids, resins, flavonoids, tannins, sterol, saponins, etc. The root, stem, and leaf parts of Adathoda beddomei are most often used in indigenous medicine. Moreover, the root bark is also used to cure several conditions, including leprosy, fever, and bleeding. Objective: Some important bioactive metabolites were obtained from endophytes bacteria and analyzed through various techniques (NMR, MASS, FTIR, HPLC, and UV- spectrophotometer) for their bioactive secondary metabolites. Methods: In silico calculation was performed to reveal bioactive metabolites with the potential to be antibacterial, and their primary mode of action may include dissolving bacterial and fungal cell walls. Results: The antimicrobial activity of Adathoda beddomei was demonstrated against different pathogenic and non-pathogenic bacteria. Identification of endophytes was done based on external morphological characteristics with the help of a scanning electron microscope (SEM). Conclusion: Natural compounds derived from endophyte bacteria with a very low molecular mass can be used to discover new and important structures for different pharmaceuticals and agrochemicals.

Construction of a Cosmid-Based Ultraefficient Genomic Library System for Filamentous Fungi of the Genus Aspergillus.

Filamentous fungi of the genus Aspergillus include producers of industrially important organic acids, enzymes, and secondary metabolites, as well as pathogens of many plants and animals. Novel genes in the Aspergillus genome are potentially crucial for the fermentation and drug industries (e.g., agrochemicals and antifungal drugs). A research approach based on classical genetics is effective for identifying functionally unknown genes. During analyses based on classical genetics, mutations must be identified easily and quickly. Herein, we report the development of a cosmid-based plasmid pTOCK1 and the use of a genomic library of Aspergillus nidulans constructed using pTOCK1. The cosmid-based genomic library was used for convenient auxotrophic mutants (pyroA and pabaB), as well as mutants with abnormal colony morphology (gfsA) and yellow conidia (yA), to obtain library clones complementary to these phenotypes. The complementary strain could be obtained through a single transformation, and the cosmid could be rescued. Thus, our cosmid library system can be used to identify the causative gene in a mutant strain.

Polyphenols Influence the Development of Endometrial Cancer by Modulating the Gut Microbiota.

Dysbiosis of the microbiota in the gastrointestinal tract can induce the development of gynaecological tumours, particularly in postmenopausal women, by causing DNA damage and alterations in metabolite metabolism. Dysbiosis also complicates cancer treatment by influencing the body's immune response and disrupting the sensitivity to chemotherapy drugs. Therefore, it is crucial to maintain homeostasis in the gut microbiota through the effective use of food components that affect its structure. Recent studies have shown that polyphenols, which are likely to be the most important secondary metabolites produced by plants, exhibit prebiotic properties. They affect the structure of the gut microbiota and the synthesis of metabolites. In this review, we summarise the current state of knowledge, focusing on the impact of polyphenols on the development of gynaecological tumours, particularly endometrial cancer, and emphasising that polyphenol consumption leads to beneficial modifications in the structure of the gut microbiota.

Integrating network pharmacology and renal metabonomics to reveal the protective mechanism of resveratrol on gouty nephropathy.

Resveratrol (Res) has been demonstrated to have beneficial effects on gouty nephropathy (GN). However, the mechanisms of Res on GN remain unclear. This study aimed to investigate the mechanisms of Res on GN. In this study, network pharmacology technology was used to predict the Res targets in the prevention and treatment of GN. Renal metabonomics was used to identify differential metabolites in kidney tissue of GN model rats. Finally, molecular docking technology was used to verify the binding ability of Res to key targets. Metabonomics analysis showed that 24 potentially important metabolites were involved in the prevention and treatment of GN with Res. After exposure to Res, metabolite levels normalized. The network pharmacology analysis showed that 24 key targets were involved in the prevention and treatment of GN disease. According to the metabolite-gene network diagram, we identified two core genes, PTGS1 and PTGS2, and found that both were involved in the arachidonic acid metabolism pathway. Molecular docking further verified the affinity of Res binding to PTGS1 and PTGS2. In conclusion, the mechanism of Res against GN may be the regulation of arachidonic acid metabolism through the regulation of PTGS 1 and PTGS 2.

Bacterial Secondary Metabolite Activation Through Epigenetic Modifiers: A Systematic Review

Bacteria have produced many important secondary metabolites, especially in the pharmaceutical industry. However, the increase in the rediscovery rate of the known compound has been inconvenient to researchers and the pharmaceutical industry. Nevertheless, genome mining in bacteria has uncovered several cryptic metabolic pathways that may be key to discovering new secondary metabolites. The conventional laboratory environment, however, limits the metabolic pathways of microorganisms, making it impossible for secondary metabolites to be produced. As a result, researchers began using epigenetics to change the expression of the genes that code for secondary metabolites in microorganisms. Using epigenetics modifiers, secondary metabolite gene clusters are activated without altering the bacterial DNA sequence. This review article focuses on the different epigenetic changes and how they affect gene expression to activate the synthesis of secondary metabolites in bacteria.

The Impact of Harvesting Mechanization on Oolong Tea Quality.

Mechanization is the inevitable future of tea harvesting, but its impact on tea chemistry and quality remains uncertain. Our study examines untargeted metabolomic data from 185 oolong tea products (Tieguanyin) made from leaves harvested by hand or machine based on UPLC-QToF-MS analysis. The data revealed a minimum 50% loss for over half of the chemicals in the machine-harvested group, including catechins, theaflavin, gallic acid, chlorogenic acid, and kaempferol-3-gluocside. Integrating sensory evaluation, OPLS-DA identified the six most important metabolites as significant contributors to sensory decline caused by harvesting mechanization. Furthermore, our research validates the possibility of using DD-SIMCA modelling with untargeted metabolomic data for distinguishing handpicked from machine-harvested tea products. The model was able to achieve 93% accuracy. This study provides crucial insights into the chemical and sensory shifts during mechanization, along with tools to manage and monitor these changes.

Multidisciplinary approach combining food metabolomics and epidemiology identifies meglutol as an important bioactive metabolite in tempe, an Indonesian fermented food

This study introduces a multidisciplinary approach to investigate bioactive food metabolites often overlooked due to their low concentrations. We integrated an in-house food metabolite library (n = 494), a human metabolite library (n = 891) from epidemiological studies, and metabolite pharmacological databases to screen for food metabolites with potential bioactivity. We identified six potential metabolites, including meglutol (3-hydroxy-3-methylglutarate), an understudied low-density lipoprotein (LDL)-lowering compound. We further focused on meglutol as a case study to showcase the range of characterizations achievable with this approach. Green pea tempe was identified to contain the highest meglutol concentration (21.8 ± 4.6 mg/100 g). Furthermore, we identified a significant cross-sectional association between plasma meglutol (per 1-standard deviation) and lower LDL cholesterol in two Hispanic adult cohorts (n = 1,628) (β [standard error]: −5.5 (1.6) mg/dl, P = 0.0005). These findings highlight how multidisciplinary metabolomics can serve as a systematic tool for discovering and enhancing bioactive metabolites in food, such as meglutol, with potential applications in personalized dietary approaches for disease prevention.

Association of tryptophan pathway metabolites with mortality and effectiveness of nutritional support among patients at nutritional risk: secondary analysis of a randomized clinical trial.

Tryptophan is an essential amino acid and is the precursor of many important metabolites and neurotransmitters. In malnutrition, the availability of tryptophan is reduced, potentially putting patients at increased risks. Herein, we investigated the prognostic implications of the tryptophan metabolism in a secondary analysis of the Effect of Early Nutritional Support on Frailty, Functional Outcomes, and Recovery of Malnourished Medical Inpatients Trial (EFFORT), a randomized, controlled trial comparing individualized nutritional support to usual care in patients at risk for malnutrition. Among 238 patients with available measurements, low plasma levels of metabolites were independently associated with 30-day mortality with adjusted hazard ratios (HR) of 1.77 [95% CI 1.05-2.99, p 0.034] for tryptophan, 3.49 [95% CI 1.81-6.74, p < 0.001] for kynurenine and 2.51 [95% CI 1.37-4.63, p 0.003] for serotonin. Nutritional support had more beneficial effects on mortality in patients with high tryptophan compared to patients with low tryptophan levels (adjusted HR 0.61 [95% CI 0.29-1.29] vs. HR 1.72 [95% CI 0.79-3.70], p for interaction 0.047). These results suggest that sufficient circulating levels of tryptophan might be a metabolic prerequisite for the beneficial effect of nutritional interventions in this highly vulnerable patient population.

Integrated metabolomic and transcriptomic dynamic profiles of endopleura coloration during fruit maturation in three walnut cultivars

BackgroundThe color of endopleura is a vital factor in determining the economic value and aesthetics appeal of nut. Walnuts (Juglans) are a key source of edible nuts, high in proteins, amino acids, lipids, carbohydrates. Walnut had a variety endopleura color as yellow, red, and purple. However, the regulation of walnut endopleura color remains little known.ResultsTo understand the process of coloration in endopleura, we performed the integrative analysis of transcriptomes and metabolomes at two developmental stages of walnut endopleura. We obtained total of 4,950 differentially expressed genes (DEGs) and 794 metabolites from walnut endopleura, which are involved in flavonoid and phenolic biosynthesis pathways. The enrichment analysis revealed that the cinnamic acid, coniferyl alcohol, naringenin, and naringenin-7-O-glucoside were important metabolites in the development process of walnut endopleura. Transcriptome and metabolome analyses revealed that the DEGs and differentially regulated metabolites (DRMs) were significantly enriched in flavonoid biosynthesis and phenolic metabolic pathways. Through co-expression analysis, CHS (chalcone synthase), CHI (chalcone isomerase), CCR (cinnamoyl CoA reductase), CAD (cinnamyl alcohol dehydrogenase), COMT (catechol-Omethyl transferase), and 4CL (4-coumaroyl: CoA-ligase) may be the key genes that potentially regulate walnut endopleura color in flavonoid biosynthesis and phenolic metabolic pathways.ConclusionsThis study illuminates the metabolic pathways and candidate genes that underlie the endopleura coloration in walnuts, lay the foundation for further study and provides insights into controlling nut’s colour.

Secondhand Smoke Exposure Measured in Urinary Cotinine Levels and Severity of Pediatric Sleep Apnea

Exposure to secondhand smoke has been associated with numerous health problems in children, including obstructive sleep apnea. Secondhand smoke exposure may be a risk factor for increased pediatric sleep apnea severity. To assess the association of secondhand smoke exposure (SHSe), quantified by urinary cotinine levels, with severity of obstructive sleep apnea (OSA) in children. This was a prospective cohort trial including pediatric patients from 3 to 16 years of age with sleep-disordered breathing who underwent a polysomnogram at a tertiary-level children's hospital in the US in either March 2014 to October 2016 or March 2020 to March 2021. Urine specimens were analyzed for cotinine, an important metabolite of nicotine. Each child's caregiver completed a validated SHSe questionnaire. Data were analyzed from February to June 2023. OSA and secondhand smoke. SHSe and severity of pediatric OSA, quantified by urinary cotinine levels and obstructive apnea hypopnea index (AHI) scores. Secondary outcomes were association of urinary cotinine levels with nadir oxygen saturation, sleep-related quality of life measured by the OSA-18 questionnaire, and caregiver-reported smoking habits (collected through a questionnaire). The study included 116 patients with a median (IQR) age of 6 (5-9) years, among whom 51 (45%) had obesity. The median (IQR) AHI was 3.0 (1.2-8.0), with 28 children (30.0%) having severe disease (AHI >10). Thirty-four children (29.0%) were found to have a positive result for urine cotinine screening, with a mean (SD) level of 11.7 (9.4) ng/mL. The percentage of children with SHSe was less than anticipated. There was no association identified between urinary cotinine levels and either AHI (ρ = -0.04; 95% CI, -0.22 to 0.15) or nadir oxygen saturation (ρ = -0.07; 95% CI, -0.26 to 0.11). Furthermore, SHSe was not associated with the presence of severe OSA (odds ratio, 0.70; 95% CI, 0.26 to 1.90). Children whose caregivers reported indoor SHSe were more likely to have a detectable urinary cotinine level (odds ratio, 20.3; 95% CI, 6.67 to 61.8). This cohort study did not identify any clinically meaningful association between SHSe, quantified by urinary cotinine level, and pediatric OSA severity. Future research with a larger number of children with SHSe is needed to confirm these findings and determine whether SHSe affects OSA treatment outcomes in children.

Two at once: simultaneous increased production of astaxanthin and mycosporines in a single batch culture using a Phaffia rhodozyma mutant strain.

Phaffia rhodozyma is a basidiomycetous yeast characterized by its production of the carotenoid pigment astaxanthin, which holds high commercial value for its significance in aquaculture, cosmetics and as nutraceutics, and the UV-B-absorbing compound mycosporine-glutaminol-glucoside (MGG), which is of great biotechnological relevance for its incorporation into natural sunscreens. However, the industrial exploitation has been limited to the production of astaxanthin in small quantities. On the other hand, the accumulation of MGG in P. rhodozyma was recently reported and could add value to the simultaneous production of both metabolites. In this work, we obtain a mutant strain that overproduces both compounds, furthermore we determined how the accumulation of each is affected by the carbon-to-nitrogen ratio and six biotic and abiotic factors. The mutant obtained produces 159% more astaxanthin (470.1μgg-1) and 220% more MGG (57.9mgg-1) than the parental strain (295.8μgg-1 and 26.2mgg-1 respectively). Furthermore, we establish that the carotenoids accumulate during the exponential growth phase while MGG accumulates during the stationary phase. The carbon-to-nitrogen ratio affects each metabolite differently, high ratios favoring carotenoid accumulation while low ratios favoring MGG accumulation. Finally, the accumulation of both metabolites is stimulated only by photosynthetically active radiation and low concentrations of hydrogen peroxide. The mutant strain obtained is the first hyper-productive mutant capable of accumulating high concentrations of MGG and astaxanthin described to date. The characterization of how both compounds accumulate during growth and the factors that stimulate their accumulation, are the first steps toward the future commercial exploitation of strains for the simultaneous production of two biotechnologically important metabolites.

Sensitivity of Chinese Hickory to Soil Acidification and Important Plant Metabolites in Response to Soil Acidification

Sensitivity of Chinese Hickory to Soil Acidification and Important Plant Metabolites in Response to Soil Acidification