Enhancing productivity, modifying biochemical parameters, and regulating the phenylpropanoid pathway in 'Le-Conte' pears through optimal protocatechuic acid treatments.

BACKGROUND: This study aimed to investigate the impact of protocatechuic acid (PRC) treatments on the productivity and fruit quality of 'Le-Conte' pears, with a specific focus on productivity, stone cells content, and antioxidant activity. The research spanned over three consecutive cultivating seasons, with the first season serving as a preliminary study to determine the optimal PRC concentrations and the most effective number of spray applications. During the initial season, response surface methodology (RSM) was employed to optimize PRC concentration and application frequency. PRC was evaluated at concentrations ranging from 50 to 400 ppm, with treatment frequencies of either once or twice. Considering the optimal conditions obtained from RSM results, PRC treatments at 200 ppm and 300 ppm were applied twice, and their respective effects were studied in comparison to the control in the following seasons. RESULTS: RSM results indicated that PRC at 200 and 300 ppm, applied twice, once during full bloom and again three weeks later, yielded the most significant effects. Subsequent studies revealed that PRC treatments had a substantial impact on various aspects of fruit production and quality. Applying 300 ppm PRC once during full bloom and again three weeks later resulted in higher fruit set percentages, lower fruit abscission, and enhanced fruit yield compared to untreated trees. Additionally, the 200 ppm PRC treatment maintained physicochemical characteristics such as fruit color, increased total soluble solids (TSS), and total sugar, and maintained higher ascorbic acid content and antioxidant capacity in the fruits while reducing stone cells content and lignin. Notably, enzyme activities related to phenylpropanoid metabolism and stone cells, including phenylalanine ammonia-lyase (PAL), cinnamate-4-hydroxylase (C4H), 4-Coumarate-CoA Ligase (4CL), cinnamyl alcohol dehydrogenase (CAD), and cinnamoyl-CoA reductase (CCR), as well as peroxidase, polyphenol oxidase, and laccase, were significantly regulated by PRC treatments. CONCLUSION: Overall, this study suggests that PRC treatments are suitable for enhancing pear yield and quality, with PRC at 200 ppm being the more recommended option over 300 ppm. This approach serves as an effective strategy for achieving a balance between enhancing the productivity and fruit quality of 'Le-Conte' pears.

AMF inhibit the production of phenolic acid autotoxins at the seed-filling stage in soybeans with continuous monocropping.

BACKGROUND: Soybean is the main oil crop in Northeast China. Continuous monocropping is more commonly used for soybean production due to rising market demand and arable land constraints. However, autotoxic substances, such as phenolic acids, produced by continuously cropped soybean can reduce yield and quality. The mycorrhiza formed of Arbuscular mycorrhizal fungi (AMF) and plant roots regulate the metabolic activities of the host plant and increase its disease resistance. The main purpose of this study was to inhibit the production of phenolic acids and determine the adverse effects on the growth of continuous monocropping soybean by inoculating Funneliformis mosseae (F. mosseae). RESULTS: Transcriptomics results showed that the production of phenolic acids in continuous monocropping soybean roots was mainly regulated by the expression of the CHS6, PCL1, SAMT, SRG1, and ACO1 genes, and the expression of these genes was significantly downregulated after inoculation with F. mosseae. Metabolomics results showed that continuous monocropping soybean roots inoculated with F. mosseae inhibited phenolic acid production through the phenylpropane biosynthetic, α-linoleic acid, linoleic acid, and other metabolic pathways. Phenolic acids in the phenylpropane metabolic pathway, such as 4-hydroxybenzoic acid, phthalic acid, and vanillic acid, decreased significantly after inoculation with F. mosseae. The combined analysis of the two showed that genes such as YLS9 and ARF3 were positively correlated with 4-hydroxybenzoic acid and so on, while genes such as CHS6 and SRG1 were negatively correlated with butyric acid and so on. CONCLUSION: F. mosseae regulated the expression of functional genes and related phenolic acid metabolic pathways produced by continuous monocropping soybean roots, inhibiting the production of phenolic acid autotoxic substances in continuous cropped soybean, and slowing down the disturbance of continuous monocropping. This study provides a new solution for continuous monocropping of plants to overcome the autotoxicity barrier and provides a new basis for the development and utilization of AMF as a biological agent.

Biodegradation of DEP, DIBP, and BBP by a psychrotolerant Sphingobium yanoikuyae strain P4: Degradation potentiality and mechanism study.

Phthalic acid esters (PAEs) are human made chemicals widely used as plasticizers to enhance the flexibility of plastic products. Due to the lack of chemical bonding between phthalates and plastics, these materials can easily enter the environment. Deleterious effects caused by this chemo-pollutant have drawn the attention of the scientific community to remediate them from different ecosystem. In this context, many bacterial strains have been reported across different habitats and Sphingobium yanoikuyae strain P4 is among the few psychrotolerant bacterial species reported to biodegrade simple and complex phthalates. In the present study, biodegradation of three structurally different PAEs viz., diethyl phthalate (DEP), di-isobutyl phthalate (DIBP), and butyl benzyl phthalate (BBP) have been investigated by the strain P4. Quantitative analyses through High-performance liquid chromatography (HPLC) revealed that the bacterium completely degraded 1 g/L of DEP, DIBP, and BBP supplemented individually in minimal media pH 7.0 within 72, 54, and 120 h of incubation, respectively, at 28 °C and under shake culture condition (180 rpm). In addition, the strain could grow in minimal media supplemented individually with up to 3 g/L of DEP and 10.0 g/L of DIBP and BBP at 28 °C and pH 7.0. The strain also could grow in metabolites resulting from biodegradation of DEP, DIBP, and BBP, viz. n-butanol, isobutanol, butyric acid, ethanol, benzyl alcohol, benzoic acid, phthalic acid, and protocatechuic acid. Furthermore, phthalic acid and protocatechuic acid were also detected as degradation pathway metabolites of DEP and DIBP by HPLC, which gave an initial idea about the biodegradation pathway(s) of these phthalates.

Acidification induce chemical and microbial variation in tea plantation soils and bacterial degradation of the key acidifying phenolic acids.

Camellia sinensis is an important economic plant grown in southern subtropical hilly areas, especially in China, mainly for the production of tea. Soil acidification is a significant cause of the reduction of yield and quality and continuous cropping obstacles in tea plants. Therefore, chemical and microbial properties of tea growing soils were investigated and phenolic acid-degrading bacteria were isolated from a tea plantation. Chemical and ICP-AES investigations showed that the soils tested were acidic, with pH values of 4.05-5.08, and the pH negatively correlated with K (p < 0.01), Al (p < 0.05), Fe and P. Aluminum was the highest (47-584 mg/kg) nonessential element. Based on high-throughput sequencing, a total of 34 phyla and 583 genera were identified in tea plantation soils. Proteobacteria and Acidobacteria were the main dominant phyla and the highest abundance of Acidobacteria was found in three soils, with nearly 22% for the genus Gp2. Based on the functional abundance values, general function predicts the highest abundance, while the abundance of amino acids and carbon transport and metabolism were higher in soils with pH less than 5. According to Biolog Eco Plate™ assay, the soil microorganisms utilized amino acids well, followed by polymers and phenolic acids. Three strains with good phenolic acid degradation rates were obtained, and they were identified as Bacillus thuringiensis B1, Bacillus amyloliquefaciens B2 and Bacillus subtilis B3, respectively. The three strains significantly relieved the inhibition of peanut germination and growth by ferulic acid, p-coumaric acid, p-hydroxybenzoic acid, cinnamic acid, and mixed acids. Combination of the three isolates showed reduced relief of the four phenolic acids due to the antagonist of B2 against B1 and B3. The three phenolic acid degradation strains isolated from acidic soils display potential in improving the acidification and imbalance in soils of C. sinensis.

Ectopic Production of 3,4-Dihydroxybenzoate in Planta Affects Cellulose Structure and Organization.

Lignocellulosic biomass is a highly sustainable and largely carbon dioxide neutral feedstock for the production of biofuels and advanced biomaterials. Although thermochemical pretreatment is typically used to increase the efficiency of cell wall deconstruction, genetic engineering of the major plant cell wall polymers, especially lignin, has shown promise as an alternative approach to reduce biomass recalcitrance. Poplar trees with reduced lignin content and altered composition were previously developed by overexpressing bacterial 3-dehydroshikimate dehydratase (QsuB) enzyme to divert carbon flux from the shikimate pathway. In this work, three transgenic poplar lines with increasing QsuB expression levels and different lignin contents were studied using small-angle neutron scattering (SANS) and wide-angle X-ray scattering (WAXS). SANS showed that although the cellulose microfibril cross-sectional dimension remained unchanged, the ordered organization of the microfibrils progressively decreased with increased QsuB expression. This was correlated with decreasing total lignin content in the QsuB lines. WAXS showed that the crystallite dimensions of cellulose microfibrils transverse to the growth direction were not affected by the QsuB expression, but the crystallite dimensions parallel to the growth direction were decreased by ∼20%. Cellulose crystallinity was also decreased with increased QsuB expression, which could be related to high levels of 3,4-dihydroxybenzoate, the product of QsuB expression, disrupting microfibril crystallization. In addition, the cellulose microfibril orientation angle showed a bimodal distribution at higher QsuB expression levels. Overall, this study provides new structural insights into the impact of ectopic synthesis of small-molecule metabolites on cellulose organization and structure that can be used for future efforts aimed at reducing biomass recalcitrance.

Enhancing metabolic efficiency via novel constitutive promoters to produce protocatechuic acid in Escherichia coli.

The antioxidant molecule protocatechuic acid (PCA) can also serve as a precursor for polymer building blocks. PCA can be produced in Escherichia coli overexpressing 3-dehydroshikimate dehydratase (DSD), an enzyme that catalyses the transformation of 3-dehydroshikimate to PCA. Nevertheless, optimizing the expression rate of recombinant enzymes is a key factor in metabolic engineering when producing biobased chemicals. In this study, a degenerate synthetic promoter approach was investigated to improve further the production of PCA. By limited screening of a randomized promoter library made using pSEVA221 plasmid in E. coli, three novel synthetic constitutive promoters were selected that increased the PCA yield from glucose by 10-21% compared to the inducible T7-promoter. RT-qPCR analysis showed that the DSD gene, regulated by the synthetic promoters, had high expression during the exponential phase, albeit the gene expression level dropped 250-fold during stationary phase. Besides the increased product yield, the synthetic promoters avoided the need for a costly inducer for gene expression. Screening of the entire promoter library is likely to provide more positive hits. The study also shows that E. coli transformed with the DSD gene on either pSEVA221 or pCDFDuet plasmids exhibit background PCA levels (~ 0.04 g/L) in the absence of a transcriptional regulatory element. KEY POINTS: • Degenerate synthetic promoters are remarkable tools to produce protocatechuic acid. • The constitutive synthetic promoters did not affect the growth rate of the bacterial host. • The use of constitutive synthetic promoters avoids the need for the costly inducer.

Comparative pharmacognosy and secondary metabolite analysis of Balanophorae herbs from different sources.

The Balanophorae are not only traditional Chinese herbal medicines but also functional foods with diverse sources. This study aimed to distinguish pharmacognostic characteristics and secondary metabolites among different species of Balanophorae. Eight species of Balanophorae herbs were harvested, including 21 batches with 209 samples. Ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry was used to analyze secondary metabolites of Balanophorae from 21 sources. Targeted metabolomic analysis was performed to compare differences among the groups. Rhopalocnemis phalloide and B. indica can be identified by their pharmacognostic characteristics. Then, 41 secondary metabolites were identified or characterized in the mixed extracts of the 209 samples, mainly phenolic acids, flavonoids, and their derivatives. The distribution of these secondary metabolites revealed apparent differences among different species. In addition, targeted metabolomic analysis suggested that the secondary metabolite profiles of seven species of Balanophorae showed noticeable differences, and differences were also observed among different growing regions. Finally, five important metabolic markers were screened to successfully distinguish B. laxiflora, B. harlandii, and B. polyandra, including three phenolic acids and two flavonoids. This is the first study to systematically compare both the morphology and secondary metabolites among different sources of Balanophorae, which could provide effective information for identifying diverse species.

In Vitro Digestion of Polyphenolic Compounds and the Antioxidant Activity of Acorn Flour and Pasta Enriched with Acorn Flour.

Acorn flour is a rich source of nutrients and is beneficial to human health due to, among other things, its low glycemic index and polyphenol content. In order to obtain more accurate data on the levels and activities of the substances tested after ingestion and digestion, it may be beneficial to use a simulated in vitro digestion method. Therefore, the objective of the present study was to elucidate the content of polyphenols, individual phenolic acids, flavonoids and antiradical properties of acorn flour and pasta enriched with acorn flour before and after simulated in vitro gastrointestinal digestion. The results indicate that the total polyphenol content (TPC), flavonoid content and radical scavenging activity exhibited an increasing trend following the initial digestion stage and a decreasing trend following the second stage. Nevertheless, the levels of phenolic acids demonstrated an increase in both digestion phases. The digestion processes of polyphenols in acorn flour differ significantly from those in pasta. In the case of pasta, total polyphenols, phenolic acids and flavonoids, as well as free radical scavenging properties, demonstrated a decreasing trend following each digestion stage.

Genome-Wide Identification and Functional Analysis of Salvia miltiorrhiza MicroRNAs Reveal the Negative Regulatory Role of Smi-miR159a in Phenolic Acid Biosynthesis.

MicroRNAs (miRNAs) are a group of endogenous small non-coding RNAs in plants. They play critical functions in various biological processes during plant growth and development. Salvia miltiorrhiza is a well-known traditional Chinese medicinal plant with significant medicinal, economic, and academic values. In order to elucidate the role of miRNAs in S. miltiorrhiza, six small RNA libraries from mature roots, young roots, stems, mature leaves, young leaves and flowers of S. miltiorrhiza and one degradome library from mixed tissues were constructed. A total of 184 miRNA precursors, generating 137 known and 49 novel miRNAs, were genome-widely identified. The identified miRNAs were predicted to play diversified regulatory roles in plants through regulating 891 genes. qRT-PCR and 5' RLM-RACE assays validated the negative regulatory role of smi-miR159a in SmMYB62, SmMYB78, and SmMYB80. To elucidate the function of smi-miR159a in bioactive compound biosynthesis, smi-miR159a transgenic hairy roots were generated and analyzed. The results showed that overexpression of smi-miR159a caused a significant decrease in rosmarinic acid and salvianolic acid B contents. qRT-PCR analysis showed that the targets of smi-miR159a, including SmMYB62, SmMYB78, and SmMYB80, were significantly down-regulated, accompanied by the down-regulation of SmPAL1, SmC4H1, Sm4CL1, SmTAT1, SmTAT3, SmHPPR1, SmRAS, and SmCYP98A14 genes involved in phenolic acid biosynthesis. It suggests that smi-miR159a is a significant negative regulator of phenolic acid biosynthesis in S. miltiorrhiza.

Evaluation of Polyphenols Synthesized in Mature Seeds of Common Bean (Phaseolus vulgaris L.) Advanced Mutant Lines.

This study aimed to investigate the availability of flavonoids, anthocyanins, and phenolic acids in mutant bean seeds, focusing on M7 mutant lines, and their corresponding initial and local cultivars. HPLC-DAD-MS/MS and HPLC-MS/MS were used to analyze twenty-eight genotypes of common bean. The obtained results suggest that the mutations resulted in four newly synthesized anthocyanins in the mutant bean seeds, namely, delphinidin 3-O-glucoside, cyanidin 3-O-glucoside, pelargonidin 3-O-glucoside, and petunidin 3-O-glucoside, in 20 accessions with colored seed shapes out of the total of 28. Importantly, the initial cultivar with white seeds, as well as the mutant white seeds, did not contain anthocyanins. The mutant lines were classified into groups based on their colors as novel qualitative characteristics. Five phenolic acids were further quantified: ferulic, p-coumaric, caffeic, sinapic, and traces of chlorogenic acids. Flavonoids were represented by epicatechin, quercetin, and luteolin, and their concentrations in the mutant genotypes were several-fold superior compared to those of the initial cultivar. All mutant lines exhibited higher concentrations of phenolic acids and flavonoids. These findings contribute to the understanding of the genetics and biochemistry of phenolic accumulation and anthocyanin production in common bean seeds, which is relevant to health benefits and might have implications for common bean breeding programs and food security efforts.

Salicylic acid promotes phenolic acid biosynthesis for the production of phenol acid-rich barley sprouts.

BACKGROUND: Phenolic acid exhibits a variety of well-known physiological functions. In this study, optimal germination conditions to ensure total phenolic acid enrichment in barley sprouts induced by salicylic acid treatment and its effects on sprout physiology and activity, as well as the gene expression of key enzymes for phenolic acid biosynthesis, were investigated. RESULTS: When sprouts were treated with 1 mmol L-1 salicylic acid during germination and germinated at 25 °C for 4 days, the phenolic acid content was 1.82 times that of the control, reaching 1221.54 µg g-1 fresh weight. Salicylic acid significantly increased the activity of phenylalanine aminolase and cinnamic acid-4-hydroxylase and the gene expression of phenylalanine aminolase, cinnamic acid-3-hydroxylase, cinnamic acid-4-hydroxylase, 4-coumaric acid-coenzyme A, caffeic acid O-methyltransferase, and ferulate-5-hydroxylase in barley sprouts. However, salicylic acid treatment significantly increased malondialdehyde and H2O2 content, H2O2 and O2 - fluorescence intensity, as well as significantly decreasing sprout length and fresh weight. Salicylic acid treatment markedly increased the activity of peroxidase and catalase and the gene expression of peroxidase, catalase, and ascorbate peroxidase in barley sprouts. CONCLUSION: Salicylic acid treatment during barley germination significantly promoted the enrichment of total phenolic acid by increasing the activities and gene expression levels of enzymes involved in the phenolic acid biosynthesis pathway. Salicylic acid induced the accumulation of reactive oxygen species, inhibited sprout growth, and activated the antioxidant system. This study provides a basis for the future development of functional foods using phenol acid-rich plants as raw materials. © 2024 Society of Chemical Industry.

[Content of secondary metabolites and antioxidant activities of Lonicera japonica flowers at different developmental stages from Shandong province].

This study established an ultrasound-assisted extraction-high performance liquid chromatography method for simulta-neously determinining the content of 11 bioactive compounds including iridoids, phenolic acids, and flavonoids in Lonicera japonica flowers. The flowers at six stages from the rice bud stage(ML) to the golden flower stage(JH) of L. japonica varieties 'Sijuhua' and 'Beihua No.1' in two planting bases in Shandong province were collected. The established method was employed to determine the content of 11 target compounds, on the basis of which the dynamics of active components in L. japonica sampels during different development stages was investigated. The correlation analysis was carried out to reveal the correlations of the content of iridoids, phenolic acids, and flavonoids. Furthermore, the antioxidant activities of samples at different developmental stages were determined, and the relationship between antioxidant activity and chemical components was analyzed by the correlation analysis. The results showed that the total content of the 11 components in 'Sijihua' changed in a "W" pattern from the ML to JH, being the highest at the ML and the second at the slight white stage(EB). The total content of 11 compounds in 'Beihua No.1' was the highest at the ML and decreased gra-dually from the ML to JH. The samples of 'Sijihua' had higher content of iridoids and lower content of phenolic acids than those of 'Beihua No.1'. The content of flavonoids and phenolic acids showed a positive correlation(R~2=0.90, P<0.05) in 'Sijihua' but no obvious correlation in 'Beihua No.1'. The antioxidant activity and phenolic acid content showed positive correlations, with the determination coefficients(R~2) of 0.84(P<0.05) in 'Beihua No.1' and 0.73(P<0.05) in 'Sijihua'. The antioxidant activity of both varieties was the strongest at the ML and the second at the EB. This study revealed that the content dynamics of iridoids, phenolic acids, and flavonoids in 'Sijihua' and 'Beihua No.1' cultivated in Shandong province during different developmental stages. The results indicated that the antioxidant activity of L. japonica flowers was significantly correlated with the content of phenolic acids at different deve-lopmental stages, which provided a basis for determining the optimum harvest time of L. japonica flowers.

Recent Advances in Microbial Metabolic Engineering for Production of Natural Phenolic Acids.

Phenolic acids are important natural bioactive compounds with varied physiological functions. They are extensively used in food, pharmaceutical, cosmetic, and other chemical industries and have attractive market prospects. Compared to plant extraction and chemical synthesis, microbial fermentation for phenolic acid production from renewable carbon sources has significant advantages. This review focuses on the structural information, physiological functions, current applications, and biosynthesis pathways of phenolic acids, especially advances in the development of metabolically engineered microbes for the production of phenolic acids. This review provides useful insights concerning phenolic acid production through metabolic engineering of microbial cell factories.

Metabolic Engineering of Pseudomonas putida KT2440 for De Novo Biosynthesis of Vanillic Acid.

Vanillic acid (VA), as a plant-derived phenolic acid compound, has widespread applications and good market prospects. However, the traditional production process cannot meet market demand. In this study, Pseudomonas putida KT2440 was used for de novo biosynthesis of VA. Multiple metabolic engineering strategies were applied to construct these P. putida-based cell factories, including the introduction of a Hs-OMTopt, engineering the cofactor S-adenosylmethionine supply pathway through the overexpression of metX and metH, reforming solubility of Hs-OMTopt, increasing a second copy of Hs-OMTopt, and the optimization of the fermentation medium. The resulting strain, XCS17, de novo biosynthesized 5.4 g/L VA from glucose in a fed-batch fermentation system; this is the highest VA production titer reported up to recently. This study showed that P. putida KT2440 is a robust platform for achieving the effective production of phenolic acids.

Potential roles of hydroxybenzoate paralytic shellfish toxins in modulating toxin biokinetics in scallops.

Paralytic shellfish toxins (PSTs) produced by some marine dinoflagellates can cause severe human intoxication via vectors like bivalves. Toxic dinoflagellate Gymnodinium catenatum produce a novel group of hydroxybenzoate PSTs named GC toxins, but their biokinetics in bivalves haven't been well examined. In this experiment, we analyzed PSTs in bay scallops Argopecten irradians exposed to G. catenatum (strain MEL11) to determine their accumulation, elimination, anatomical distribution, and biotransformation. To our surprise, up to 30% of the PSTs were accumulated in the adductor muscle of scallops at the end of the experiment, and the toxicity of adductor muscle exceeded the regulatory limit of 800 µg STXeq/kg in only 6 days. High concentration of toxins in the adductor muscle are likely linked to the rapid transfer of GC toxins from viscera to other tissues. Moreover, most GC toxins in scallops were found rapidly transformed to decarbamoyl toxins through enzyme-mediated hydrolysis, which was further supported by the in vitro incubation experiments. Our study demonstrates that GC toxins actively participate in toxin distribution and transformation in scallops, which may increase the risks of food poisoning associated with the consumption of scallop adductor muscle. ENVIRONMENTAL IMPLICATION: The negative impacts of harmful algal blooms (HABs) have become a global environmental concern under the joint effects of cultural eutrophication and climate change. Our study, targeted on the biokinetics of paralytic shellfish toxins in scallops exposed to Gymnodinium catenatum producing unique GC toxins, aims to elucidate potential risks of seafood poisoning associated with GC toxins. The findings of this study will help us to understand the roles of GC toxins in seafood poisoning, and to develop effective management strategies against toxic algal blooms and phycotoxins.

Withania somnifera (L.) Dunal: Enhanced production of withanolides and phenolic acids from hairy root culture after application of elicitors.

Withania somnifera (L.) Dunal is an important indigenous medicinal plant with extensive pharmaceutical potential. The root is the main source of major bioactive compounds of this plant species including withanolides, withanine, phenolic acids, etc. Hairy root culture (HRC) is a crucial method for low-cost production of active compounds on a large scale. Four different Agrobacterium rhizogenes strains have been used for the hairy root induction. Maximum transformation efficiency (87.34 ± 2.13%) was achieved with A4 bacterial strain-mediated transformed culture. The genetic transformation was confirmed by using specific primers of seven different genes. Seven HR (Hairy root) lines were selected after screening 29 HR lines based on their fast growth rate and high accumulation of withanolides and phenolic acids content. Two biotic and three abiotic elicitors were applied to the elite root line to trigger more accumulation of withanolides and phenolic acids. While all the elicitors effectively increased withanolides and phenolic acids production, among the five different elicitors, salicylic acid (4.14 mg l-1) induced 11.49 -fold increase in withanolides (89.07 ± 2.75 mg g-1 DW) and 5.34- fold increase in phenolic acids (83.69 ± 3.11 mg g- 1 DW) after 5 days of elicitation compared to the non-elicited culture (7.75 ± 0.63 mg g-1 DW of withanolides and 15.66 ± 0.92 mg g-1 DW of phenolic acids). These results suggest that elicitors can tremendously increase the biosynthesis of active compounds in this system; thus, the HRC of W. somnifera is cost-effective and can be efficiently used for the industrial production of withanolides and phenolic acids.

Plant hormones and phenolic acids response to UV-B stress in Rhododendron chrysanthum pall.

Our study aims to identify the mechanisms involved in regulating the response of Rhodoendron Chrysanthum Pall. (R. chrysanthum) leaves to UV-B exposure; phosphorylated proteomics and metabolomics for phenolic acids and plant hormones were integrated in this study. The results showed that UV-B stress resulted in the accumulation of salicylic acid and the decrease of auxin, jasmonic acid, abscisic acid, cytokinin and gibberellin in R. chrysanthum. The phosphorylated proteins that changed in plant hormone signal transduction pathway and phenolic acid biosynthesis pathway were screened by comprehensive metabonomics and phosphorylated proteomics. In order to construct the regulatory network of R. chrysanthum leaves under UV-B stress, the relationship between plant hormones and phenolic acid compounds was analyzed. It provides a rationale for elucidating the molecular mechanisms of radiation tolerance in plants.

Heterologous expression and enzymatic characteristics of sulfatase from Lactobacillus plantarum dy-1.

Barley, rich in bioactive components including dietary fiber, polyphenolic compounds and functional proteins, exhibits health benefits such as regulating glucose and lipid metabolism. Previous studies have found that the content and composition of free phenolic acids in barley may be significantly changed by fermentation with the laboratory patented strain Lactobacillus plantarum dy-1 (L. p dy-1), but the mechanism of enzymatic release of phenolic acid remains to be elucidated. Based on this, this study aimed to identify the key enzyme in L. p dy-1 responsible for releasing the bound phenolic acid and to further analyze its enzymatic properties. The Carbohydrate-Active enZYmes database revealed that L. p dy-1 encodes 7 types of auxiliary enzymes, among which we have identified a membrane sulfatase. The enzyme gene LPMS05445 was heterologous to that expressed in E. coli, and a recombinant strain was induced to produce the target protein and purified. The molecular weight of the purified enzyme was about 59.9 kDa, with 578.21 U mg-1 enzyme activity. The optimal temperature and pH for LPMS05445 expression were 40 °C and 7.0, respectively. Furthermore, enzymatic hydrolysis by LPMS05445 can obviously change the surface microstructure of dietary fiber from barley bran and enhance the release of bound phenolic acid, thereby increasing the free phenolic acid content and improving its physiological function. In conclusion, sulfatase produced by Lactobacillus plantarum dy-1 plays a key role in releasing bound phenolic acids during the fermentation of barley.

[Advances in the microbial synthesis of active ingredients in cosmetics].

With the rapid development of the medical beauty industry, functional skin care products become increasingly popular. The functions of cosmetics mainly depend on the active ingredients, which are mainly proteins, peptides, polysaccharides, phenolic acids, terpenes, vitamins, and amino acids. These active ingredients endow cosmetics with skin repairing, moistening, whitening, UV protecting, and anti-aging effects. They are mainly obtained through biological extraction and chemical synthesis. In recent years, with the development of biomanufacturing, microbial synthesis of active ingredients in cosmetics has been widely studied and applied. This article reviews the research progresses in the production of natural products including collagens, peptides, hyaluronic acid, polyphenols, terpenes, and vitamins by microbial synthetic biotechnology. Moreover, this article highlighted the synthetic pathways, metabolic regulation, and prospects of the natural products, providing a reference for subsequent microbial synthesis of active ingredients in cosmetics.

Unveiling biotransformation of free flavonoids into phenolic acids and Chromones alongside dynamic migration of bound Phenolics in Lactobacillus-fermented lychee pulp.

Lactobacillus strains have emerged as promising probiotics for enhancing the bioactivities of plant-based foods associated with flavonoid biotransformation. Employing microbial fermentation and mass spectrometry, we explored flavonoid metabolism in lychee pulp fermented separately by Lactiplantibacillus plantarum and Limosilactobacillus fermentum. Two novel metabolites, 3,5,7-trihydroxychromone and catechol, were exclusively identified in L. plantarum-fermented pulp. Concomitant with consumption of catechin and quercetin glycosides, dihydroquercetin glycosides, 2,4-dihydroxybenzoic acid and p-hydroxyphenyllactic acid were synthesized by two strains through hydrogenation and fission of C-ring. Quantitative analysis revealed that bound phenolics were primarily located in water-insoluble polysaccharides in lychee pulp. Quercetin 3-O-rutinoside was partially liberated from water-insoluble polysaccharides and migrated to water-soluble polysaccharides during fermentation. Meanwhile, substantial accumulations in short-chain fatty acids (increased 1.45 to 3.08-fold) and viable strains (increased by 1.97 to 2.00 Log10 CFU/mL) were observed in fermentative pulp. These findings provide broader insight into microbial biotransformation of phenolics and possible guidance for personalized nutrition.