Strain-specific metabolomic diversity of Lactiplantibacillus plantarum under aerobic and anaerobic conditions.

The chemotaxonomic diversity of 20 Lactiplantibacillus plantarum strains was investigated using non-targeted metabolite profiling under different culture conditions. Multivariate and metabolic pathway analyses based on GC-MS and LC-MS/MS datasets showed that amino acid metabolism, especially 2-hydroxy acids, was enriched under aerobic conditions (AE), whereas fatty acid & sugar metabolism was increased under anaerobic conditions (AN). Based on the metabolite profiles, L. plantarum strains were clustered into three main groups (A, B, and C). Overall, 79 and 83 significantly discriminant metabolites were characterized as chemical markers of AE and AN growth conditions, respectively. Notably, alcohols were more abundant in group A whereas amino acids, peptides, purines, and pyrimidines were significantly higher in group C. 2-hydroxy acids and oxylipins biosynthesized through amino acid and fatty acid metabolism, respectively, were more abundant in groups A and B. Furthermore, we observed a strong correlation between the chemical diversity of L. plantarum groups and their antioxidant activity from metabolite extracts. We propose a non-targeted metabolomic workflow to comprehensively characterize the chemodiversity of L. plantarum strain under different culture conditions, which may help reveal specific biomarkers of individual strains depending on the culture conditions.

Exploring the metabolomic diversity of plant species across spatial (leaf and stem) components and phylogenic groups.

BACKGROUND: Plants have been used as an important source of indispensable bioactive compounds in various cosmetics, foods, and medicines. However, the subsequent functional annotation of these compounds seems arduous because of the largely uncharacterized, vast metabolic repertoire of plant species with known biological phenotypes. Hence, a rapid multi-parallel screening and characterization approach is needed for plant functional metabolites. RESULTS: Fifty-one species representing three plant families, namely Asteraceae, Fabaceae, and Rosaceae, were subjected to metabolite profiling using gas chromatography time-of-flight mass spectrometry (GC-TOF-MS) and ultrahigh-performance liquid chromatography quadrupole orbitrap ion trap tandem mass spectrometry (UHPLC-Q-orbitrap-MS/MS) as well as multivariate analyses. Partial least squares discriminant analysis (PLS-DA) of the metabolite profiling datasets indicated a distinct clustered pattern for 51 species depending on plant parts (leaves and stems) and relative phylogeny. Examination of their relative metabolite contents showed that the extracts from Fabaceae plants were abundant in amino acids, fatty acids, and genistein compounds. However, the extracts from Rosaceae had higher levels of catechin and ellagic acid derivatives, whereas those from Asteraceae were higher in kaempferol derivatives and organic acids. Regardless of the different families, aromatic amino acids, branch chain amino acids, chlorogenic acid, flavonoids, and phenylpropanoids related to the shikimate pathway were abundant in leaves. Alternatively, certain amino acids (proline, lysine, and arginine) as well as fatty acids levels were higher in stem extracts. Further, we investigated the associated phenotypes, i.e., antioxidant activities, affected by the observed spatial (leaves and stem) and intra-family metabolomic disparity in the plant extracts. Pearson's correlation analysis indicated that ellagic acid, mannitol, catechin, epicatechin, and quercetin derivatives were positively correlated with antioxidant phenotypes, whereas eriodictyol was positively correlated with tyrosinase inhibition activity. CONCLUSIONS: This work suggests that metabolite profiling, including multi-parallel approaches and integrated bioassays, may help the expeditious characterization of plant-derived metabolites while simultaneously unraveling their chemodiversity.

Fathoming Aspergillus oryzae metabolomes in formulated growth matrices.

The stochasticity of Aspergillus oryzae (Trivially: the koji mold) pan-metabolomes commensurate with its ubiquitously distributed landscapes, i.e. growth matrices have been seemed uncharted since its food fermentative systems are mostly being investigated. In this review, we explicitly have discussed the likely tendencies of A. oryzae metabolomes pertaining to its growth milieu formulated with substrate matrices of varying nature, composition, texture, and associated physicochemical parameters. We envisaged typical food matrices, namely, meju, koji, and moromi as the semi-natural cultivation models toward delineating the metabolomic patterns of the koji mold, which synergistically influences the organoleptic and functional properties of the end products. Further, we highlighted how tailored conditions in sub-natural growth matrices, i.e. synthetic cultivation media blends, inducers, and growth surfaces, may influence A. oryzae metabolomes and targeted phenotypes. In general, the sequential or synchronous growth of A. oryzae on formulated matrices results in a number of metabolic tradeoffs with its immediate microenvironment influencing its adaptive and regulatory metabolomes. In broader context, evaluating the metabolic plasticity of A. oryzae relative to the tractable variables in formulated growth matrices might help approximate its growth and metabolism in the more complex natural matrices and environs. These approaches may considerably help in the design and manipulation of hybrid cultivation systems towards the efficient harnessing of commercial molds.

Integrated Metabolomics and Transcriptomics Unravel the Metabolic Pathway Variations for Different Sized Beech Mushrooms.

Beech mushrooms (Hypsizygus marmoreus) are largely relished for their characteristic earthy flavor, chewy-texture, and gustatory and nutritional properties in East Asian societies. Intriguingly, the aforementioned properties of beech mushroom can be subsumed under its elusive metabolome and subtle transcriptome regulating its various stages of growth and development. Herein, we carried out an integrated metabolomic and transcriptomic profiling for different sized beech mushrooms across spatial components (cap and stipe) to delineate their signature pathways. We observed that metabolite profiles and differentially expressed gene (DEGs) displayed marked synergy for specific signature pathways according to mushroom sizes. Notably, the amino acid, nucleotide, and terpenoid metabolism-related metabolites and genes were more abundant in small-sized mushrooms. On the other hand, the relative levels of carbohydrates and TCA intermediate metabolites as well as corresponding genes were linearly increased with mushroom size. However, the composition of flavor-related metabolites was varying in different sized beech mushrooms. Our study explores the signature pathways associated with growth, development, nutritional, functional and organoleptic properties of different sized beech mushrooms.

Strategy for Screening of Antioxidant Compounds from Two Ulmaceae Species Based on Liquid Chromatography-Mass Spectrometry.

Liquid chromatography-mass spectrometry (LC-MS)-based untargeted metabolomics implies that annotated metabolites can serve as potential markers of the associated bioactivities of plant extracts. Firstly, we selected Aphananthe aspera and Zelkova serrata (Family: Ulmaceae) from 16 Korean plant species based on their distinct principal component analysis (PCA) patterns in LC-MS datasets and antioxidant activity assays. Further, we chose 40% solid-phase extraction (SPE) extracts of the two species displaying the highest antioxidant activities coupled with distinct PCA patterns. Examining the metabolite compositions of the 40% SPE extracts, we observed relatively higher abundances of quercetin, kaempferol, and isorhamnetin O-glucosides for A. aspera, whereas quercetin, isorhamnetin O-glucuronides, and procyanidin dimer were relatively higher in Z. serrata. These metabolites were clearly distinguished in pathway map and displayed strong positive correlations with antioxidant activity. Further, we performed preparative high-performance liquid chromatography (prep-HPLC) analysis coupled with the 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) assay to validate their functional correlations. As a result, quercetin O-sophoroside was determined as the main antioxidant in A. aspera, while isorhamnetin O-glucuronide and procyanidin dimer were the primary antioxidants in Z. serrata. The current study suggests that the LC-MS-based untargeted metabolomics strategy can be used to illuminate subtle metabolic disparities as well as compounds associated with bioactivities.

Metabolite fingerprinting, pathway analyses, and bioactivity correlations for plant species belonging to the Cornaceae, Fabaceae, and Rosaceae families.

KEY MESSAGE: A multi-parallel approach gauging the mass spectrometry-based metabolite fingerprinting coupled with bioactivity and pathway evaluations could serve as an efficacious tool for inferring plant taxonomic orders. Thirty-four species from three plant families, namely Cornaceae (7), Fabaceae (9), and Rosaceae (18) were subjected to metabolite profiling using gas chromatography-time-of-flight-mass spectrometry (GC-TOF-MS) and ultrahigh performance liquid chromatography-linear trap quadrupole-ion trap-mass spectrometry (UHPLC-LTQ-IT-MS/MS), followed by multivariate analyses to determine the metabolites characteristic of these families. The partial least squares discriminant analysis (PLS-DA) revealed the distinct clustering pattern of metabolites for each family. The pathway analysis further highlighted the relatively higher proportions of flavonols and ellagitannins in the Cornaceae family than in the other two families. Higher levels of phenolic acids and flavan-3-ols were observed among species from the Rosaceae family, while amino acids, flavones, and isoflavones were more abundant among the Fabaceae family members. The antioxidant activities of plant extracts were measured using ABTS, DPPH, and FRAP assays, and indicated that extracts from the Rosaceae family had the highest activity, followed by those from Cornaceae and Fabaceae. The correlation map analysis positively links the proportional concentration of metabolites with their relative antioxidant activities, particularly in Cornaceae and Rosaceae. This work highlights the pre-eminence of the multi-parallel approach involving metabolite profiling and bioactivity evaluations coupled with metabolic pathways as an efficient methodology for the evaluation of plant phylogenies.

Ultrahigh Pressure Processing Produces Alterations in the Metabolite Profiles of Panax ginseng.

Ultrahigh pressure (UHP) treatments are non-thermal processing methods that have customarily been employed to enhance the quality and productivity of plant consumables. We aimed to evaluate the effects of UHP treatments on ginseng samples (white ginseng: WG; UHP-treated WG: UWG; red ginseng: RG; UHP-treated RG: URG; ginseng berries: GB; and UHP-treated GB: UGB) using metabolite profiling based on ultrahigh performance liquid chromatography-linear trap quadrupole-ion trap-tandem mass spectrometry (UHPLC-LTQ-IT-MS/MS) and gas chromatography time-of-flight mass spectrometry (GC-TOF-MS). Multivariate data analyses revealed a clear demarcation among the GB and UGB samples, and the phenotypic evaluations correlated the highest antioxidant activities and the total phenolic and flavonoid compositions with the UGB samples. Overall, eight amino acids, seven organic acids, seven sugars and sugar derivatives, two fatty acids, three notoginsenosides, three malonylginsenosides, and three ginsenosides, were identified as significantly discriminant metabolites between the GB and UGB samples, with relatively higher proportions in the latter. Ideally, these metabolites can be used as quality biomarkers for the assessment of ginseng products and our results indicate that UHP treatment likely led to an elevation in the proportions of total extractable metabolites in ginseng samples.

Metabolite Profiling Reveals the Effect of Dietary Rubus coreanus Vinegar on Ovariectomy-Induced Osteoporosis in a Rat Model.

The study was aimed at exploring the curative effects of Rubus coreanus (RC) vinegar against postmenopausal osteoporosis by using ovariectomized rats as a model. The investigations were performed in five groups: sham, ovariectomized (OVX) rats without treatment, low-dose RC vinegar (LRV)-treated OVX rats, high-dose RC vinegar (HRV)-treated OVX rats and alendronate (ALEN)-treated OVX rats. The efficacy of RC vinegar was evaluated using physical, biochemical, histological and metabolomic parameters. Compared to the OVX rats, the LRV and HRV groups showed positive effects on the aforementioned parameters, indicating estrogen regulation. Plasma metabolome analysis of the groups using gas chromatography-time of flight mass spectrometry (GC-TOF-MS) and ultra-performance liquid chromatography quadrupole-TOF-MS (UPLC-Q-TOF-MS) with multivariate analysis revealed 19 and 16 metabolites, respectively. Notably, the levels of butyric acid, phenylalanine, glucose, tryptophan and some lysophosphatidylcholines were marginally increased in RC vinegar-treated groups compared to OVX. However, the pattern of metabolite levels in RC vinegar-treated groups was found similar to ALEN, but differed significantly from that in sham group. The results highlight the prophylactic and curative potential of dietary vinegar against postmenopausal osteoporosis. RC vinegar could be an effective natural alternative for the prevention of postmenopausal osteoporosis.

Swainsonine, a novel fungal metabolite: optimization of fermentative production and bioreactor operations using evolutionary programming.

The optimization of bioreactor operations towards swainsonine production was performed using an artificial neural network coupled evolutionary program (EP)-based optimization algorithm fitted with experimental one-factor-at-a-time (OFAT) results. The effects of varying agitation (300-500 rpm) and aeration (0.5-2.0 vvm) rates for different incubation hours (72-108 h) were evaluated in bench top bioreactor. Prominent scale-up parameters, gassed power per unit volume (P g/V L, W/m(3)) and volumetric oxygen mass transfer coefficient (K L a, s(-1)) were correlated with optimized conditions. A maximum of 6.59 ± 0.10 µg/mL of swainsonine production was observed at 400 rpm-1.5 vvm at 84 h in OFAT experiments with corresponding P g/VL and K L a values of 91.66 W/m(3) and 341.48 × 10(-4) s(-1), respectively. The EP optimization algorithm predicted a maximum of 10.08 µg/mL of swainsonine at 325.47 rpm, 1.99 vvm and 80.75 h against the experimental production of 7.93 ± 0.52 µg/mL at constant K L a (349.25 × 10(-4) s(-1)) and significantly reduced P g/V L (33.33 W/m(3)) drawn by the impellers.

Urine metabolomics unravel the effects of short-term dietary interventions on oxidative stress and inflammation: a randomized controlled crossover trial.

Dietary biomarkers in urine remain elusive when evaluating diet-induced oxidative stress and inflammation. In our previous study, we conducted a randomized controlled crossover trial to compare the short-term (4-weeks) effects of the balanced Korean diet (BKD) with Western diets, including the 2010 dietary guidelines for Americans (2010 DGA) and typical American diet (TAD), on various metabolic indices in obese Korean adults. Building on this work, the current research focuses on the impact of these dietary interventions on oxidative stress (d-ROMs and BAP) and inflammation (CRP, TNF-α, IL-6, IL-1ß, MCP-1) biomarkers in serum, and the concurrent urine metabolomes. Each dietary regimen was in silico and experimentally examined for their antioxidant levels using ABTS, DPPH, and FRAP assays, as well as total flavonoid (TFC) and total phenolic (TPC) contents. We assessed post-intervention variations in oxidative stress and inflammation biomarkers in serum, as well as the urine metabolite profiles for the participants (n = 48, average age: 41 years). Antioxidant contents and associated total antioxidant capacity (TAC) were significantly higher for the recommended diets (BKD and 2010 DGA) compared to TAD (p < 0.05). Butanol extracts from recommended diets (BKD and 2010 DGA) showed significantly higher antioxidant activity compared to TAD in ABTS (p < 0.01), DPPH, and FRAP (p < 0.05) assays. Consistent results were observed in total phenolic and flavonoid contents, mirroring their respective antioxidant activities. Following the intervention period, oxidative stress & inflammation markers in serum varied marginally, however, the urine metabolite profiles were clearly demarcated for the BKD and Western dietary groups (PC1 = 5.41%). For BKD group, the pre- and post-intervention urine metabolite profiles were clearly segregated (PLS2 = 2.93%). Compared to TAD, urine extracts from the recommended dietary group showed higher abundance of benzoic acid & phenolic derivatives (VIP > 0.7, p < 0.05). Metabolites associated with oxidative stress were observed higher in the urine samples from Western dietary groups compared to BKD. Urine metabolomics data delineated the post-intervention effects of three dietary interventions which corroborates the respective findings for their effects on metabolic indices.

Bidirectional Interactions between Green Tea (GT) Polyphenols and Human Gut Bacteria.

Green tea (GT) polyphenols undergo extensive metabolism within gastrointestinal tract (GIT), where their derivatives compounds potentially modulate the gut microbiome. This biotransformation process involves a cascade of exclusive gut microbial enzymes which chemically modify the GT polyphenols influencing both their bioactivity and bioavailability in host. Herein, we examined the in vitro interactions between 37 different human gut microbiota and the GT polyphenols. UHPLC-LTQ-Orbitrap-MS/MS analysis of the culture broth extracts unravel that genera Adlercreutzia, Eggerthella and Lactiplantibacillus plantarum KACC11451 promoted C-ring opening reaction in GT catechins. In addition, L. plantarum also hydrolyzed catechin galloyl esters to produce gallic acid and pyrogallol, and also converted flavonoid glycosides to their aglycone derivatives. Biotransformation of GT polyphenols into derivative compounds enhanced their antioxidant bioactivities in culture broth extracts. Considering the effects of GT polyphenols on specific growth rates of gut bacteria, we noted that GT polyphenols and their derivate compounds inhibited most species in phylum Actinobacteria, Bacteroides, and Firmicutes except genus Lactobacillus. The present study delineates the likely mechanisms involved in the metabolism and bioavailability of GT polyphenols upon exposure to gut microbiota. Further, widening this workflow to understand the metabolism of various other dietary polyphenols can unravel their biotransformation mechanisms and associated functions in human GIT.

Optimization of different process variables for the production of an indolizidine alkaloid, swainsonine from Metarhizium anisopliae.

Swainsonine is a polyhydroxylated indolizidine alkaloid having anticancer, antimetastatic, antiproliferative and immunomodulatory activities and also potential therapeutic applications against AIDS. In the present study, ten isolates of M. anisopliae were screened and enzyme assayed for the production of swainsonine in different media (Complex oatmeal, Czapekdox media with and without lysine (8% w/v) and Sabouraud dextrose broth (SDB)). Among these strains, ARSEF 1724 (UM8) was found to produce highest amount of swainsonine (1.34 µg/l) after 72 h of incubation under shake flask conditions at 180 rpm and 28 °C in complex oatmeal media. In order to maximize the yield of swainsonine the media composition including macro and micronutrients were optimized. The process variables including the chemical factors like carbon sources, nitrogen sources of both organic and inorganic nature and pH with constant inoculum size (1 × 10(8) spores/ml) were screened using classical one-factor-at-a-time (OFAT) approach to find their optimum levels. The present study shows that the nutrient requirement is specific for each strain of Metarhizium. Oatmeal extract (6%) was found to be the best supporting media along with nitrogen source, glucose (2%) as best carbon source and pH (~5) as the best for swainsonine production.

Non-obligate pairwise metabolite cross-feeding suggests ammensalic interactions between Bacillus amyloliquefaciens and Aspergillus oryzae.

Bacterial-fungal metabolite trade-offs determine their ecological interactions. We designed a non-obligate pairwise metabolite cross-feeding (MCF) between Bacillus amyloliquefaciens and Aspergillus oryzae. Cross-feeding Aspergillus metabolites (MCF-1) affected higher growth and biofilm formation in Bacillus. LC-MS/MS-based multivariate analyses (MVA) showed variations in the endogenous metabolite profiles between the cross-fed and control Bacillus. We observed and validated that Aspergillus-derived oxylipins were rapidly depleted in Bacillus cultures concomitant with lowered secretion of cyclic lipopeptides (CLPs). Conversely, Bacillus extracts cross-fed to Aspergillus (MCF-2) diminished its mycelial growth and conidiation. Fungistatic effects of Bacillus-derived cyclic surfactins were temporally reduced following their hydrolytic linearization. MVA highlighted disparity between the cross-fed (MCF-2) and control Aspergillus cultures with marked variations in the oxylipin levels. We conclude that the pairwise MCF selectively benefitted Bacillus while suppressing Aspergillus, which suggests their ammensalic interaction. Widening this experimental pipeline across tailored communities may help model and simulate BFIs in more complex microbiomes.

Integrated Metabolomics and Volatolomics for Comparative Evaluation of Fermented Soy Products.

Though varying metabolomes are believed to influence distinctive characteristics of different soy foods, an in-depth, comprehensive analysis of both soluble and volatile metabolites is largely unreported. The metabolite profiles of different soy products, including cheonggukjang, meju, doenjang, and raw soybean, were characterized using LC-MS (liquid chromatography-mass spectrometry), GC-MS (gas chromatography-mass spectrometry), and headspace solid-phase microextraction (HS-SPME) GC-MS. Principal component analysis (PCA) showed that the datasets for the cheonggukjang, meju, and doenjang extracts were distinguished from the non-fermented soybean across PC1, while those for cheonggukjang and doenjang were separated across PC2. Volatile organic compound (VOC) profiles were clearly distinct among doenjang and soybean, cheonggukjang, and meju samples. Notably, the relative contents of the isoflavone glycosides and DDMP (2,3-dihydro-2,5-dihydroxy-6-methyl-4H-pyran-4-one) conjugated soyasaponins were higher in soybean and cheonggukjang, compared to doenjang, while the isoflavone aglycones, non-DDMP conjugated soyasaponins, and amino acids were significantly higher in doenjang. Most VOCs, including the sulfur containing compounds aldehydes, esters, and furans, were relatively abundant in doenjang. However, pyrazines, 3-methylbutanoic acid, maltol, and methoxyphenol were higher in cheonggukjang, which contributed to the characteristic aroma of soy foods. We believe that this study provides the fundamental insights on soy food metabolomes, which determine their nutritional, functional, organoleptic, and aroma characteristics.

Critical thresholds of 1-Octen-3-ol shape inter-species Aspergillus interactions modulating the growth and secondary metabolism.

In fungi, contactless interactions are mediated via the exchange of volatile organic compounds (VOCs). As these pair-wise interactions are fundamental to complex ecosystem, we examined the effects of inter-species VOCs trade-offs in Aspergillus flavus development. First, we exposed A. flavus to the A. oryzae volatilome (Treatment-1) with highest relative abundance of 1-Octen-3-ol (~ 4.53 folds) among the C-8 VOCs. Further, we examined the effects of gradient titers of 1-Octen-3-ol (Treatment-2: 100-400 ppm/day) in a range that elicits natural interactions. On 7-day, VOC-treated A. flavus displayed significantly reduced growth and sclerotial counts (p < 0.01) coupled with higher conidial density (T2100-200 ppm/day, p < 0.01) and α-amylase secretion (T2200 ppm/day, p < 0.01), compared to the untreated sets. Similar phenotypic trends except for α-amylases were evident for 9-day incubated A. flavus in T2. The corresponding metabolomics data displayed a clustered pattern of secondary metabolite profiles for VOC-treated A. flavus (PC1-18.03%; PC2-10.67%). Notably, a higher relative abundance of aflatoxin B1 with lower levels of most anthraquinones, indole-terpenoids, and oxylipins was evident in VOC-treated A. flavus. The observed correlations among the VOC-treatments, phenotypes, and altered metabolomes altogether suggest that the distant exposure to the gradient titers of 1-Octen-3-ol elicits an attenuated developmental response in A. flavus characterized by heightened virulence.

Unraveling dynamic metabolomes underlying different maturation stages of berries harvested from Panax ginseng.

BACKGROUND: Ginseng berries (GBs) show temporal metabolic variations among different maturation stages, determining their organoleptic and functional properties. METHODS: We analyzed metabolic variations concomitant to five different maturation stages of GBs including immature green (IG), mature green (MG), partially red (PR), fully red (FR), and overmature red (OR) using mass spectrometry (MS)-based metabolomic profiling and multivariate analyses. RESULTS: The partial least squares discriminant analysis score plot based on gas chromatography-MS datasets highlighted metabolic disparity between preharvest (IG and MG) and harvest/postharvest (PR, FR, and OR) GB extracts along PLS1 (34.9%) with MG distinctly segregated across PLS2 (18.2%). Forty-three significantly discriminant primary metabolites were identified encompassing five developmental stages (variable importance in projection > 1.0, p < 0.05). Among them, most amino acids, organic acids, 5-C sugars, ethanolamines, purines, and palmitic acid were detected in preharvest GB extracts, whereas 6-C sugars, phenolic acid, and oleamide levels were distinctly higher during later maturation stages. Similarly, the partial least squares discriminant analysis based on liquid chromatography-MS datasets displayed preharvest and harvest/postharvest stages clustered across PLS1 (11.1 %); however, MG and PR were separated from IG, FR, and OR along PLS2 (5.6 %). Overall, 24 secondary metabolites were observed significantly discriminant (variable importance in projection > 1.0, p < 0.05), with most displaying higher relative abundance during preharvest stages excluding ginsenosides Rg1 and Re. Furthermore, we observed strong positive correlations between total flavonoid and phenolic metabolite contents in GB extracts and antioxidant activity. CONCLUSION: Comprehending the dynamic metabolic variations associated with GB maturation stages rationalize their optimal harvest time per se the related agroeconomic traits.

Metabolomic response of Perilla frutescens leaves, an edible-medicinal herb, to acclimatize magnesium oversupply.

High salt accumulation, resulting from the rampant use of chemical fertilizers in greenhouse cultivation, has deleterious effects on plant growth and crop yield. Herein, we delineated the effects of magnesium (Mg) oversupply on Perilla frutescens leaves, a traditional edible and medicinal herb used in East-Asian countries. Mg oversupply resulted in significantly higher chlorophyll content coupled with lower antioxidant activities and growth, suggesting a direct effect on subtle metabolomes. The relative abundance of bioactive phytochemicals, such as triterpenoids, flavonoids, and cinnamic acids, was lower in the Mg-oversupplied plants than in the control. Correlation analysis between plant phenotypes (plant height, total fresh weight of the shoot, leaf chlorophyll content, and leaf antioxidant content) and the altered metabolomes in P. frutescens leaves suggested an acclimatization mechanism to Mg oversupply. In conclusion, P. frutescens preferentially accumulated compatible solutes, i.e., carbohydrates and amino acids, to cope with higher environmental Mg levels, instead of employing secondary and antioxidative metabolism.

Comparative Metabolomics Unravel the Effect of Magnesium Oversupply on Tomato Fruit Quality and Associated Plant Metabolism.

In general, greenhouse cultivation involves the rampant application of chemical fertilizers, with the aim of achieving high yields. Oversaturation with mineral nutrients that aid plant growth, development, and yield may lead to abiotic stress conditions. We explore the effects of excess magnesium on tomato plant metabolism, as well as tomato fruit quality using non-targeted mass spectrometry (MS)-based metabolomic approaches. Tomato plants were subjected to three different experiments, including high magnesium stress (MgH), extremely high magnesium stress (MgEH), and a control with optimal nutrient levels. Leaves, roots, and fruits were harvested at 16 weeks following the treatment. A metabolic pathway analysis showed that the metabolism induced by Mg oversupply was remarkably different between the leaf and root. Tomato plants allocated more resources to roots by upregulating carbohydrate and polyamine metabolism, while these pathways were downregulated in leaves. Mg oversupply affects the fruit metabolome in plants. In particular, the relative abundance of threonic acid, xylose, fucose, glucose, fumaric acid, malic acid, citric acid, oxoglutaric acid, threonine, glutamic acid, phenylalanine, and asparagine responsible for the flavor of tomato fruits was significantly decreased in the presence of Mg oversupply. Altogether, we concluded that Mg oversupply leads to drastically higher metabolite transport from sources (fully expanded leaves) to sinks (young leaves and roots), and thus, produces unfavorable outcomes in fruit quality and development.

Untargeted Metabolomics Toward Systematic Characterization of Antioxidant Compounds in Betulaceae Family Plant Extracts.

Plant species have traditionally been revered for their unparalleled pharmacognostic applications. We outline a non-iterative multi-parallel metabolomic-cum-bioassay-guided methodology toward the functional characterization of ethanol extracts from the Betulaceae family plants (n = 10). We performed mass spectrometry (MS)-based multivariate analyses and bioassay-guided (ABTS antioxidant activity and cytoprotective effects against H2O2-induced cell damage) analyses of SPE fractions. A clearly distinct metabolomic pattern coupled with significantly higher bioactivities was observed for 40% methanol SPE eluate. Further, the 40% SPE eluate was subjected to preparative high-performance liquid chromatography (prep-HPLC) analysis, yielding 72 sub-fractions (1 min-1), with the highest antioxidant activities observed for the 15 min and 31 min sub-fractions. We simultaneously performed hyphenated-MS-based metabolite characterization of bioactive components for both the 40% methanol SPE fraction and its prep-HPLC sub-fraction (15 min and 31 min). Altogether, 19 candidate metabolites were mainly observed to contribute toward the observed bioactivities. In particular, ethyl gallate was mainly observed to affect the antioxidant activities of SPE and prep-HPLC fractions of Alnus firma extracts. We propose an integrated metabolomic-cum-bioassay-guided approach for the expeditious selection and characterization of discriminant metabolites with desired phenotypes or bioactivities.

Intraspecies Volatile Interactions Affect Growth Rates and Exometabolomes in Aspergillus oryzae KCCM 60345.

Volatile organic compounds (VOCs) are increasingly been recognized as the chemical mediators of mold interactions, shaping their community dynamics, growth, and metabolism. Herein, we selectively examined the time-correlated (0 D-11 D, where D = incubation days) effects of intraspecies VOC-mediated interactions (VMI) on Aspergillus oryzae KCCM 60345 (S1), following co-cultivation with partner strain A. oryzae KACC 44967 (S2), in a specially designed twin plate assembly. The comparative evaluation of S1VMI (S1 subjected to VMI with S2) and its control (S1Con) showed a notable disparity in their radial growth (S1VMI < S1Con) at 5 D, protease activity (S1VMI > S1Con) at 3-5 D, amylase activity (S1VMI < S1Con) at 3-5 D, and antioxidant levels (S1VMI > S1Con) at 3 D. Furthermore, we observed a distinct clustering pattern for gas chromatography-time of flight-mass spectrometry datasets from 5 D extracts of S1VMI and S1Con in principle component analysis (PC1: 30.85%; PC2: 10.31%) and partial least squares discriminant analysis (PLS-DA) (PLS1: 30.77; PLS2: 10.15%). Overall, 43 significantly discriminant metabolites were determined for engendering the metabolic variance based on the PLS-DA model (VIP > 0.7, p < 0.05). In general, a marked disparity in the relative abundance of amino acids (S1VMI > S1Con) at 5 D, organic acids (S1VMI > S1Con) at 5 D, and kojic acid (S1VMI < S1Con) at 5-7 D were observed. Examining the headspace VOCs shared between S1 and S2 in the twin plate for 5 D incubated samples, we observed the relatively higher abundance of C-8 VOCs (1-octen-3-ol, (5Z)-octa-1,5-dien-3-ol, 3-octanone, 1-octen-3-ol acetate) having known semiochemical functions. The present study potentially illuminates the effects of VMI on commercially important A. oryzae's growth and biochemical phenotypes with subtle details of altered metabolomes.