Important Metabolites Research Articles

Role of AplaeA in the regulation of spore production and poly(malic acid) synthesis in Aureobasidium pullulans

Poly(malic acid) (PMLA) as one of the important metabolites in Aureobasidium pullulans has great application in a variety of fields. LaeA, a global regulator capable of controlling fungal secondary metabolites, has been identified in A. pullulans. The involvement of LaeA in the biosynthesis of PMLA through direct or indirect means and its role in A. pullulans is currently unknown. Here we extracted and characterized the AplaeA gene from A. pullulans HIT-LCY3T and resolved it by bioinformatics. The function of AplaeA was subsequently characterized by Rnai-LaeA and OEX-LaeA mutants. Based on phenotypic observations of the mutant strains, it was found that the gene had a large effect on the morphology and melanin production aspects of the strain, and that overexpression of the AplaeA gene resulted in a substantial increase in spore numbers. RT-qPCR combined with protein interactions results analyzed that ApLaeA positively regulates PMLA biosynthesis by controlling the expression of core genes of PMLA biosynthesis gene cluster and other related regulatory factors. Finally, OEX-LaeA was used as the starting strain to obtain the optimal fermentation conditions. These findings illustrate the regulatory mechanism of a hypothesized global regulator, LaeA, in A. pullulans HIT-LCY3T, suggesting its potential application in industrial-scale PMLA biosynthesis.

HPTLC quantification of garcinol in three endemic Garcinia species of Assam, estimation of secondary metabolites and evaluation of in vitro antioxidant activity

AbstractGarcinol, the main polyisoprenylated benzophenone present in Garcinia species. A simple, rapid, reliable high-performance thin-layer chromatography (HPTLC) technique has been developed for simultaneous detection and quantification of garcinol in three endemic Garcinia sp. of Assam, India. While G. mangostana and G. indica have garnered extensive recognition, these lesser-known species have not received proportionate level of scientific exploration, therefore has served as the subject of investigation. Chromatographic separation was achieved using pre-coated silica gel 60 F254 plates. The optimized mobile phase (Toluene-Ethyl acetate-Formic acid, 5:4:1V/V) at 276 nm produced well-defined and sharp peaks of garcinol, maintaining a constant RF value of 0.75. The regression equation demonstrated a linear relationship with a correlation coefficient of 0.9955. The method was validated in accordance with International Conference of Harmonization guidelines (ICH), encompassing assessments for precision, accuracy, repeatability and robustness, all of which yielded low percentage of relative standard deviation values, attesting to its excellent performance. The content of garcinol found in the extracts were in the range of 0.58–0.98% w/w. In secondary metabolite analysis, significant amount of phenols (26.06 ± 1.65–57.51 ± 2.62 gallic acid equivalent mg g−1), flavonoids (11.27 ± 1.06–21.09 ± 1.34 quercetin equivalent mg g−1) and ascorbic acid (3.56 ± 0.12–3.65 ± 0.11 mg/10 g) contents were detected in the extracts. Further, the extracts exhibited good anti-radical activity, which may be attributed to the presence of important secondary metabolites. Therefore, this research establishes the three endemic Garcinia sp. as promising source of garcinol. Additionally, the developed method can be applied for routine quality control analysis of herbal formulations containing garcinol.

A MYB family transcription factor TdRCA1 from wild emmer wheat regulates anthocyanin biosynthesis in coleoptile.

As important secondary metabolites in plants, anthocyanins not only contribute to colored plants organs, but also provide protections against various biotic and abiotic stresses. In this study, a MYB transcription factor gene TdRCA1 from wild emmer wheat regulating anthocyanin biosynthesis in wheat coleoptile was identified on the short arm of chromosome 7A in common wheat genetic background. The TdRCA1 overexpression lines showed colored callus, coleoptile, auricle and stem nodes, as well as up regulation of six anthocyanin-related structural genes. The expression of TdRCA1 was activated by light in a temporal manner. While coleoptile color of 48 and 60h dark-grown seedlings changed from green to red after 24h light treatment, those grown in dark for 72 and 96h failed to develop red coleoptiles after light restoration. Interestingly, the over expression of TdRCA1 resulted in increased resistance to Fusarium crown rot, a chronic and severe fungal disease in many cereal growing regions in the world. Our results offer a better understanding of the molecular basis of coleoptile color in bread wheat.

Buddleoside-rich Chrysanthemum indicum L. extract modulates macrophage-mediated inflammation to prevent metabolic syndrome induced by unhealthy diet

BackgroundMetabolic syndrome (MetS) is a precursor to the development of many diseases (atherosclerosis, diabetes, etc.). It is marked by disruptions in glucose and lipid metabolism, along with hypertension. Numerous types of risk factors contribute to the development of the MetS, inflammation and insulin resistance are present throughout the metabolic abnormalities. Chrysanthemum indicum L. is a traditional Chinese plant used for both tea and medicine, known for its high content of total flavonoids, which are important secondary metabolites. Our research led to the extraction of a Buddleoside-Rich Chrysanthemum indicum L. extract (BUDE) which has demonstrated anti-inflammatory properties. Nonetheless, the specific role and mechanism of BUDE in preventing MetS remain unclear.MethodsThe study initially evaluated the role of BUDE in preventing MetS. Subsequently, it investigated the anti-inflammatory properties of BUDE in the liver and pancreas in response to unhealthy diets. It then examined the level of insulin resistance and pancreatic β-cell function induced by inflammation. Additionally, an lipopolysaccharide (LPS)-induced macrophage inflammation model was used to further investigate the ameliorative effects of BUDE in inflammation.ResultsBUDE has hypotensive, hypoglycemic and hypolipidemic effects. It can also resolve the imbalance between macrophage subpopulations, impede the triggering of the NF-κB signaling pathway, reduce the secretion of inflammatory mediators, ameliorate insulin resistance, and safeguard organs such as the liver and pancreas from inflammatory damage. These effects collectively contribute to preventing the development of MetS.DiscussionBUDE has the ability to modulate macrophage-mediated inflammation, leading to improved insulin resistance. Additionally, it delivers antihypertensive, hypoglycemic, and hypolipidemic effects, offering a potential for preventing MetS.

An end-to-end deep learning method for mass spectrometry data analysis to reveal disease-specific metabolic profiles

Untargeted metabolomic analysis using mass spectrometry provides comprehensive metabolic profiling, but its medical application faces challenges of complex data processing, high inter-batch variability, and unidentified metabolites. Here, we present DeepMSProfiler, an explainable deep-learning-based method, enabling end-to-end analysis on raw metabolic signals with output of high accuracy and reliability. Using cross-hospital 859 human serum samples from lung adenocarcinoma, benign lung nodules, and healthy individuals, DeepMSProfiler successfully differentiates the metabolomic profiles of different groups (AUC 0.99) and detects early-stage lung adenocarcinoma (accuracy 0.961). Model flow and ablation experiments demonstrate that DeepMSProfiler overcomes inter-hospital variability and effects of unknown metabolites signals. Our ensemble strategy removes background-category phenomena in multi-classification deep-learning models, and the novel interpretability enables direct access to disease-related metabolite-protein networks. Further applying to lipid metabolomic data unveils correlations of important metabolites and proteins. Overall, DeepMSProfiler offers a straightforward and reliable method for disease diagnosis and mechanism discovery, enhancing its broad applicability.

Chlorophyll deficiency in Agave angustifolia Haw.: unveiling the impact on secondary metabolite production.

The albino phenotype of Agave angustifolia Haw. accumulates higher levels of phenylalanine and phenylpropanoids, while the green phenotype has a greater concentration of phenolic compounds. The metabolic consequences of chlorophyll deficiency in plants continue to be a captivating field of research, especially in relation to production of metabolic compounds. This study conducts a thorough analysis of the metabolome in green (G), variegated (V), and albino (A) phenotypes of Agave angustifolia Haw. Specifically, it examines the differences in the accumulation of compounds related to the phenylpropanoid and flavonoid biosynthesis pathways. Methanol extracts of leaf and meristem tissues from the three phenotypes grown in vitro were analyzed using liquid chromatography coupled with quadrupole time-of-flight high-resolution mass spectrometry (UPLC-MS-QTOF) for untargeted metabolomics and triple quadrupole (QqQ) mass spectrometry for targeted metabolomic analyses. By employing these methods, we discovered notable differences in the levels of important metabolites such as L-phenylalanine, 4-hydroxyphenylpyruvic acid, and various flavonoids among the different phenotypes. The results of our study indicate that the A phenotype shows a significant increase in the levels of phenylalanine and phenylpropanoids in both leaf and meristem tissues. This is in contrast to a decrease in flavonoids, suggesting a metabolic reprogramming to compensate for the lack of chlorophyll. Significantly, compounds such as kaempferol-3-O-glucoside and rutin exhibited significant quantitative reduction in the A leaves, suggesting a subtle modification in the production of flavonols and potentially a changed mechanism for antioxidant protection. This study emphasizes the complex metabolic changes in A. angustifolia´s chlorophyll-deficient phenotypes, providing insight into the complex interplay between primary and secondary metabolism in response to chlorophyll deficiency. Our research not only enhances the comprehension of plant metabolism in albino phenotypes but also opens new avenues for exploring the biochemical and genetic basis of such adaptations, with potential biotechnological applications of these distinct plant variants.

Comprehensive analysis of the effects of the traditional stir-fry process on the dynamic changes of volatile metabolites in Hainan camellia oil

The traditional stir-fry process before pressing is crucial to manufacture Hainan camellia oil. To assess the effects of the stir-fry process on Hainan camellia oil, six samples across different stir-fry stages were analyzed. The stir-fry process modified odors, volatile metabolite profiles, and human health-promoting functions of Hainan camellia oil. Totally, 350 volatile metabolites were detected, and heterocyclic compounds were revealed as the main contributors of strong aroma. Potential indicators for monitoring the stir-fry degree were established. Eight key aroma volatile metabolites were identified, including three new ones (1-octen-3-one, 2,3-butanedione, and vanillin). Lipids degradation and the Millard reaction are probably the main pathways for aroma generation. Over-stir-fry treatment diminished the contents of some important volatile metabolites but increased the risk of arising burnt odor. Our work offered insights into the effects of the stir-fry process and over-stir-fry treatment on Hainan camellia oil, which is meaningful for improving the hot-pressing technique.

Bile Acid Metabolism Analysis Provides Insights into Vascular Endothelial Injury in Salt-Sensitive Hypertensive Rats.

As an unhealthy dietary habit, a high-salt diet can affect the body's endocrine system and metabolic processes. As one of the most important metabolites, bile acids can prevent atherosclerosis and reduce the risk of developing cardiovascular diseases. Therefore, in the present study, we aimed to reveal the bile acid metabolism changes in salt-sensitive hypertension-induced vascular endothelial injury. The model was established using a high-salt diet, and the success of this procedure was confirmed by detecting the levels of the blood pressure, vascular regulatory factors, and inflammatory factors. An evaluation of the histological sections of arterial blood vessels and kidneys confirmed the pathological processes in these tissues of experimental rats. Bile acid metabolism analysis was performed to identify differential bile acids between the low-salt diet group and the high-salt diet group. The results indicated that the high-salt diet led to a significant increase in blood pressure and the levels of endothelin-1 (ET-1) and tumor necrosis factor-α (TNF-α). The high-salt diet causes disorders in bile acid metabolism. The levels of four differential bile acids (glycocholic acid, taurolithocholic acid, tauroursodeoxycholic acid, and glycolithocholic acid) significantly increased in the high-salt group. Further correlation analysis indicated that the levels of ET-1 and TNF-α were positively correlated with these differential bile acid levels. This study provides new evidence for salt-sensitive cardiovascular diseases and metabolic changes caused by a high-salt diet in rats.

Functional characterization of TrGSTF15, a glutathione S-transferase gene family member, on the transport and accumulation of anthocyanins and proanthocyanidins in Trifolium repens

Anthocyanins and proanthocyanidins (PAs) are important secondary metabolites in plants, high contents of which are an important goal for quality breeding of white clover (Trifolium repens). However, the involvement of glutathione S-transferase (GST) in the transport of anthocyanins and PAs remains unexplored in white clover. This study identified 153 different TrGSTs in white clover. At the transcriptional level, compared to other TrGSTFs, TrGSTF10 and TrGSTF15 are highly expressed in the ‘Purple’ white clover, and they may work with the anthocyanin biosynthesis structural genes CHS and CHI to contribute to pigment buildup in white clover. Subcellular localization confirmed that TrGSTF10 and TrGSTF15 are located in the cytoplasm. Additionally, molecular docking experiments showed that TrGSTF10 and TrGSTF15 have similar binding affinity with two flavonoid monomers. Overexpression of TrGSTF15 complemented the deficiency of anthocyanin coloring and PA accumulation in the Arabidopsis tt19 mutant. The initial findings of this research indicate that TrGSTF15 encodes an important transporter of anthocyanin and PA in white clover, thus providing a new perspective for the further exploration of related transport and regulatory mechanisms.

Exploring flavour profile changes of strawberry fruits under different organic fertilizer strategies by combining HS-SPME-GC-MS and metabolomics

This work focused on investigating the flavour formation of strawberry fruits (SFs) at three developmental phases treated by different types of organic fertilizers. A total of 92 volatile and 8595/6244 non-volatile compounds were identified using HS-SPME-GC–MS combined with non-targeted metabolomics. The predominant volatile components in SFs include esters and terpenes, and the application of organic fertilizers increased the contribution of characteristic volatile esters to the fruity aroma of SFs. Compared to the control group (CK), the peach branch (PB) and cow straw (CS) organic fertilizer groups reduced the major green-flavor compound, 3-hexenal, by 94.25 % and 28.44 %, respectively. The amino acids, polyphenols and salicylic acids were identified as important differential metabolites, and KEGG enrichment analysis revealed that flavour formation was primarily associated with amino acids metabolism. These insights provide a valuable theoretical basis for understanding flavour formation of fruits to enhance their sensory qualities through targeted regulation.

Biochemical and structural elucidation of the L-carnitine degradation pathway of the human pathogen Acinetobacter baumannii.

Acinetobacter baumannii is an opportunistic human pathogen which can use host-derived L-carnitine as sole carbon and energy source. Recently, an L-carnitine transporter (Aci1347) and a specific monooxygense (CntA/CntB) for the intracellular cleavage of L-carnitine have been characterized. Subsequent conversion of the resulting malic semialdehyde into the central metabolite L-malate was hypothesized. Alternatively, L-carnitine degradation via D-malate with subsequent oxidation into pyruvate was proposed. Here we describe the in vitro and in vivo reconstitution of the entire pathway, starting from the as yet uncharacterized gene products of the carnitine degradation gene operon. Using recombinantly purified enzymes, enantiomer-specific formation of D-malate by the NAD(P)+-dependent malic semialdehyde dehydrogenase (MSA-DH) is demonstrated. The solved X-ray crystal structure of tetrameric MSA-DH reveals the key catalytic residues Cys290 and Glu256, accessible through opposing substrate and cofactor funnels. Specific substrate binding is enabled by Arg166, Arg284 and Ser447 while dual cofactor specificity for NAD+ and NADP+ is mediated by Asn184. The subsequent conversion of the unusual D-malate reaction product by an uncharacterized NAD+-dependent malate dehydrogenase (MDH) is shown. Tetrameric MDH is a β-decarboxylating dehydrogenase that synthesizes pyruvate. MDH experiments with alternative substrates showed a high degree of substrate specificity. Finally, the entire A. baumannni pathway was heterologously reconstituted, allowing E. coli to grow on L-carnitine as a carbon and energy source. Overall, the metabolic conversion of L-carnitine via malic semialdehyde and D-malate into pyruvate, CO2 and trimethylamine was demonstrated. Trimethylamine is also an important gut microbiota-dependent metabolite that is associated with an increased risk of cardiovascular disease. The pathway reconstitution experiments allowed us to assess the TMA forming capacity of gut microbes which is related to human cardiovascular health.

Lactate promotes the biofilm-to-invasive-planktonic transition in Salmonella enterica serovar Typhimurium via the de novo purine pathway.

Salmonella enterica serovar Typhimurium (S. Typhimurium) infection triggers an inflammatory response that changes the concentration of metabolites in the gut impacting the luminal environment. Some of these environmental adjustments are conducive to S. Typhimurium growth, such as the increased concentrations of nitrate and tetrathionate or the reduced levels of Clostridia-produced butyrate. We recently demonstrated that S. Typhimurium can form biofilms within the host environment and respond to nitrate as a signaling molecule, enabling it to transition between sessile and planktonic states. To investigate whether S. Typhimurium utilizes additional metabolites to regulate its behavior, our study delved into the impact of inflammatory metabolites on biofilm formation. The results revealed that lactate, the most prevalent metabolite in the inflammatory environment, impedes biofilm development by reducing intracellular c-di-GMP levels, suppressing the expression of curli and cellulose, and increasing the expression of flagellar genes. A transcriptomic analysis determined that the expression of the de novo purine pathway increases during high lactate conditions, and a transposon mutagenesis genetic screen identified that PurA and PurG, in particular, play a significant role in the inhibition of curli expression and biofilm formation. Lactate also increases the transcription of the type III secretion system genes involved in tissue invasion. Finally, we show that the pyruvate-modulated two-component system BtsSR is activated in the presence of high lactate, which suggests that lactate-derived pyruvate activates BtsSR system after being exported from the cytosol. All these findings propose that lactate is an important inflammatory metabolite used by S. Typhimurium to transition from a biofilm to a motile state and fine-tune its virulence.IMPORTANCEWhen colonizing the gut, Salmonella enterica serovar Typhimurium (S. Typhimurium) adopts a dynamic lifestyle that alternates between a virulent planktonic state and a multicellular biofilm state. The coexistence of biofilm formers and planktonic S. Typhimurium in the gut suggests the presence of regulatory mechanisms that control planktonic-to-sessile transition. The signals triggering the transition of S. Typhimurium between these two lifestyles are not fully explored. In this work, we demonstrated that in the presence of lactate, the most dominant host-derived metabolite in the inflamed gut, there is a reduction of c-di-GMP in S. Typhimurium, which subsequently inhibits biofilm formation and induces the expression of its invasion machinery, motility genes, and de novo purine metabolic pathway genes. Furthermore, high levels of lactate activate the BtsSR two-component system. Collectively, this work presents new insights toward the comprehension of host metabolism and gut microenvironment roles in the regulation of S. Typhimurium biology during infection.

4-Vinylpyridine copolymers for improved LC–MS tryptophan and kynurenine determination in human serum

Tryptophan (an essential amino acid) and its clinically important metabolite—kynurenine contribute to several fundamental biological processes and methods that allow their determination in biological samples are in demand. The novelty of the work was a demonstration of the utility of two polymers: 4-vinylpyridine crosslinked with trimethylolpropane trimethacrylate (poly(4VP-co-TRIM)) or 1,4-dimethacryloyloxybenzene (poly(4VP-co-14DMB))—in terms of human serum clean-up for simultaneous LC–MS determination of tryptophan and kynurenine. The goal was to achieve a reduction of the matrix effect, which is responsible for signal suppression, with minimal capture of analytes. The adsorption properties of the polymeric beads were studied by evaluating the adsorption kinetics and isotherms in model matrices. Therefore, the adsorption capacities of both molecules were not efficient, the tested 4-vinylpyridine-based copolymers have shown great promise (especially poly(4VP-co-TRIM)) as sorbents for serum clean-up. In the model human serum matrix, poly(4VP-co-TRIM) provided good recoveries of tryptophan and kynurenine (76% and 87%, respectively) and allowed for the reduction of the matrix effect. Performances of both copolymers were compared to those of commercially available sorbents (octadecylsilane, activated charcoal, and primary secondary amine).

Involvement of LaeA and Velvet Proteins in Regulating the Production of Mycotoxins and Other Fungal Secondary Metabolites.

Fungi are rich sources of secondary metabolites of agrochemical, pharmaceutical, and food importance, such as mycotoxins, antibiotics, and antitumor agents. Secondary metabolites play vital roles in fungal pathogenesis, growth and development, oxidative status modulation, and adaptation/resistance to various environmental stresses. LaeA contains an S-adenosylmethionine binding site and displays methyltransferase activity. The members of velvet proteins include VeA, VelB, VelC, VelD and VosA for each member with a velvet domain. LaeA and velvet proteins can form multimeric complexes such as VosA-VelB and VelB-VeA-LaeA. They belong to global regulators and are mainly impacted by light. One of their most important functions is to regulate gene expressions that are responsible for secondary metabolite biosynthesis. The aim of this mini-review is to represent the newest cognition of the biosynthetic regulation of mycotoxins and other fungal secondary metabolites by LaeA and velvet proteins. In most cases, LaeA and velvet proteins positively regulate production of fungal secondary metabolites. The regulated fungal species mainly belong to the toxigenic fungi from the genera of Alternaria, Aspergillus, Botrytis, Fusarium, Magnaporthe, Monascus, and Penicillium for the production of mycotoxins. We can control secondary metabolite production to inhibit the production of harmful mycotoxins while promoting the production of useful metabolites by global regulation of LaeA and velvet proteins in fungi. Furthermore, the regulation by LaeA and velvet proteins should be a practical strategy in activating silent biosynthetic gene clusters (BGCs) in fungi to obtain previously undiscovered metabolites.

Effect of cadmium toxicity on growth, physiochemical parameters and antioxidant system of castor seedlings

The research was aimed to determine the potential impact of cadmium contamination on Ricinus communis. The glucose-6-phosphate dehydrogenase (G6PDH) activity in the root was highest when exposed to 0.2 mM of Cd, with an increase of 15.63 % and 14.48 % at 0 and 24 h, respectively, compared to its control. However, citrate synthase (CS) activity declined in leaves, in contrast, to root, i.e., 12.22 % at 48 h of Cd stress. Isocitrate dehydrogenase (ICDH) activity was maximum in leaves at 0.2 mM of Cd at 0 and 24 h, i.e., 12.36 % and 13.08 % respectively, and later decreased in activity was seen in roots and leaves as the Cd stress increased. Moreover, the level of malate dehydrogenase (MDH) declined in leaves as the Cd level increased, while activity increased in roots at 0.4 mM of Cd i.e., 17.21 %, 17.52 %, and 10.53 % at 0, 24, and 48 h respectively. The important metabolite, glutathione level in the roots of SKP 84 was higher than in the leaf extract. A decline in biomass of up to 28.70 % and 30.91 % and plant length of up to 20.80 % and 26.10 % in shoot and roots, respectively, tolerance index was maximum at 0.2 mM, i.e., 98.62 % was seen. The leaves had 35.40 % catalase (CAT) activity, while the roots had 78.26 % guaiacol peroxidase (GPX) activity at 0.6 mM of Cd. At 0.2 mM of Cd, the maximum activity of ascorbate peroxidase (APX) was observed, with 67.32 % and 62.85 % activity in roots and leaves respectively. However, a reduction in the SOD activity was seen as the Cd stress increased. Increased Cd levels decreased chlorophyll but increased MDA and proline content in leaves at 0.8 mM of Cd, i.e., 82.92 % and 21.7 %, respectively. It indicated that R. communis SKP 84, a fusarium wilt resistance line, is also tolerant to Cd and can be used for phytoremediation in Cd-contaminated areas.

Influence of choline and follistatin supplementation during in vitro bovine oocyte maturation on oocyte competence and blastocyst development.

Metabolite supplementation during in vitro embryo development improves blastocyst quality, however, our understanding of the incorporation of metabolites during in vitro maturation (IVM) is limited. Two important metabolites, follistatin and choline, have beneficial impacts during in vitro culture; however, effects of supplementation during IVM are unknown. The objective of this study was to investigate combining choline and follistatin during IVM on bovine oocytes and subsequent early embryonic development. We hypothesized that supplementation of choline with follistatin would synergistically improve oocyte quality and subsequent early embryonic development. Small follicles were aspirated from slaughterhouse ovaries to obtain cumulus oocyte complexes for IVM with choline (0, 1.3 or 1.8 mM) and follistatin (0 or 10 ng/mL) supplementation in a 3 × 2 design. A subset of oocytes underwent transcriptomic analysis, the remaining oocytes were used for IVF and in vitro culture (IVC). Transcript abundance of CEPT1 tended to be reduced in oocytes supplemented with 1.8 mM choline and follistatin compared to control oocytes (P = 0.07). Combination of follistatin with 1.8 mM choline supplementation during maturation, tended (P = 0.08) to reduce CPEB4 in oocytes. In the blastocysts, HDCA8, NANOG, SAV1 and SOX2 were increased with choline 1.8 mM supplementation without follistatin (P < 0.05), while HDCA8 and SOX2 were increased when follistatin was incorporated (P < 0.05). The combination of choline and follistatin during oocyte maturation may provide a beneficial impact on early embryonic development. Further research is warranted to investigate the interaction between these two metabolites during early embryonic development and long-term influence on fetal development.

Limiting factors in the operation of photosystems I and II in cyanobacteria.

Cyanobacteria are important targets for biotechnological applications due to their ability to grow in a wide variety of environments, rapid growth rates, and tractable genetic systems. They and their bioproducts can be used as bioplastics, biofertilizers, and in carbon capture and produce important secondary metabolites that can be used as pharmaceuticals. However, the photosynthetic process in cyanobacteria can be limited by a wide variety of environmental factors such as light intensity and wavelength, exposure to UV light, nutrient limitation, temperature, and salinity. Carefully considering these limitations, modifying the environment, and/or selecting cyanobacterial species will allow cyanobacteria to be used in biotechnological applications.

Metformin in COVID-19: a magical role beyond the hyperglycemia

Coronavirus disease-2019 (COVID-19) has emerged as an aggressive viral infection in the last few years. Initially reported in the Wuhan area of the People’s Republic of China, it soon emerged across the globe. Researchers confront a worrying situation to rapidly develop effective strategies to combat this novel infection and its long-term aftereffects. To date, there have been myriad reports ranging from the repurposing of the classical antimalarial drug hydroxychloroquine to several other antiviral and anti-bacterial agents like remdesivir, favipiravir, and most recently azithromycin, which has entered clinical use in many countries for combating COVID-19 infections. Several studies have highlighted the nexus between COVID-19-associated morbidity and diabetes in a wide-ranging class of subjects ranging from pediatric cases to adults and patients with other co-morbidities. Metformin is a mainstay in the treatment of type 2 diabetes (T2D). It is safe, inexpensive, and effective and does more than merely control blood sugar levels. Important metabolites that encourage blood clotting and inflammation are also suppressed by metformin. Pro-inflammatory molecules are linked to obesity and T2D. Both are major risk factors for aggravated COVID-19. These characteristics gave rise to a hypothesis that metformin may find use as an efficacious treatment for COVID-19 especially if it decreases the inflammatory molecules that fuel the COVID-19 virus-induced effects. In this review, we attempt to elucidate the role of classical anti-diabetic medicine metformin in the treatment of COVID-19 infections by highlighting the pharmacological role of this drug during elevated glucose levels and insulin resistance. We examine how COVID-19 has correlations to diabetic physiology and thereby the possibility of repurposing metformin for COVID-19 treatment.

A sensor platform based on SERS detection/janus textile for sweat glucose and lactate analysis toward portable monitoring of wellness status

Herein we report a wearable sweat sensor of a Janus fabric based on surface enhanced Raman scattering (SERS) technology, mainly detecting the two important metabolites glucose and lactate. Janus fabric is composed of electrospinning PU on a piece of medical gauze (cotton), working as the unidirectional moisture transport component (R = 1305%) to collect and transfer sweat efficiently. SERS tags with different structures act as the probe to recognize and detect the glucose and lactate in high sensitivity. Core-shell structured gold nanorods with DTNB inside (AuNRs@DTNB@Au) are used to detect lactate, while gold nanorods with MPBA (AuNRs@MPBA) are used to detect glucose. Through the characteristic SERS information, two calibration functions were established for the concentration determination of glucose and lactate. The concentrations of glucose and lactate in sweat of a 23 years volunteer during three-stage interval running are tested to be 95.5, 53.2, 30.5 μM and 4.9, 13.9, 10.8 mM, indicating the glucose (energy) consumption during exercise and the rapid accumulation of lactate at the early stage accompanied by the subsequent relief. As expected, this sensing system is able to provide a novel strategy for effective acquisition and rapid detection of essential biomarkers in sweat.

High-tannin food enhances spatial memory and scatter-hoarding in rodents via the microbiota-gut-brain axis

BackgroundThe mutually beneficial coevolutionary relationships between rodents and plant seeds have been a theme of research in plant-animal relationships. Seed tannins are important secondary metabolites of plants that regulate the food-hoarding behavior of rodents; however, the underlying molecular mechanisms are not yet clear. In this study, we investigated whether and how seed tannins improve spatial memory and regulate the hoarding behavior of Tamias sibiricus by altering their gut microbiota.ResultsWe showed that acorn tannins not only improved spatial memory but also enhanced scatter-hoarding in T. sibiricus. Changes in the composition and function of the gut microbiota in response to tannins from acorns are closely related to these improvements. Metabonomic analyses revealed the role of gut isovaleric acid and isobutyric acid as well as serum L-tryptophan in mediating the spatial memory of T. sibiricus via the gut microbiota. The hippocampal proteome provides further evidence that the microbiota-gut-brain axis regulates spatial memory and scatter-hoarding in animals. Our study is likely the first to report that plant secondary metabolites improve hippocampal function and spatial memory and ultimately modulate food-hoarding behavior via the microbiota-gut-brain axis.ConclusionOur findings may have resolved the long-standing puzzle about the hidden role of plant secondary metabolites in manipulating food-hoarding behavior in rodents via the microbiota-gut-brain axis. Our study is important for better understanding the mutualistic coevolution between plants and animals.-v6UxNpVaqDZi2u857RxwnVideo