Production Of Bioactive Metabolites Research Articles

Bio-transforming Syzygium Cumini Kernel into Microbial Metabolites: Towards enhancing Pharmacological Characterization

Bioactive compounds of Syzygium cumini kernel bio-transformed into microbial metabolites exhibited potential increase in pharmacological characterization. Different probiotic bacterial consortia lead to the production of various bioactive metabolites. Most of the microbial metabolites derived from probiotic bacterial fermentation have pharmacological/ druglikeness properties and some metabolites have biological activities like anti-bacterial, anti-oxidant and anti-inflammatory properties. Molecular docking of microbial metabolites that have passed the rule of five criteria against the protein target of PDB ID 5IKR– cyclooxygenase-2 exhibit, enhanced anti-inflammatory property that may lead to pharmacological investigations. The binding energies of higher area percentage compounds are oxirane, hexadecyl- (-4.5kcal/mol), octadecanoic acid (-5.8kcal/mol), n-hexadecanoic acid (-4.1kcal/mol) and oleic acid (-3.8kcal/mol). Octadecanoic acid seems to show higher anti-inflammatory activity than the control drug asprin (-5.1kcal/mol).

Statistical Medium Optimization for the Production of Anti-Methicillin-Resistant Staphylococcus aureus Metabolites from a Coal-Mining-Soil-Derived Streptomyces rochei CMB47

The development of novel antibacterial drugs needs urgent action due to the global emergence of antibiotic resistance. In this challenge, actinobacterial strains from arid ecosystems are proving to be promising sources of new bioactive metabolites. The identified Streptomyces rochei strain CMB47, isolated from coal mine Saharan soil, provided an ethyl acetate extract which tested against a series of pathogens. It displayed a minimum inhibitory concentration of <0.439 µg/mL against MRSA. A statistical experimental design using a response surface methodology (RSM) based on the second-order rotatable central composite design (RCCD) was planned to develop an efficient fermentation process able to improve the bioactive metabolite production. The optimal conditions were determined for starch and NaNO3 concentrations, incubation time and the initial pH value, reaching the inhibition zone diameter of 20 mm, close to the experimental value, after validation of the model. A bioassay-guided fractionation of the crude extract provided the most active fractions, which were analyzed by HPLC equipped with a photodiode array detector and coupled online with an electrospray mass spectrometer (HPLC-DAD/ESI-MS), obtaining preliminary indications on the molecular structures of the metabolites. These results support the potential interest in further investigations into the purification and full characterization of the metabolites responsible for the biological activity observed so far.

Genome Mining and Screening for Secondary Metabolite Production in the Endophytic Fungus Dactylonectria alcacerensis CT-6.

Endophytic fungi are a treasure trove of natural products with great chemical diversity that is largely unexploited. As an alternative to the traditional bioactivity-guided screening approach, the genome-mining-based approach provides a new methodology for obtaining novel natural products from endophytes. In our study, the whole genome of an endophyte, Dactylonectria alcacerensis CT-6, was obtained for the first time. Genomic analysis indicated that D. alcacerensis CT-6 has one 61.8 Mb genome with a G+C content of 49.86%. Gene annotation was extensively carried out using various BLAST databases. Genome collinearity analysis revealed that D. alcacerensis CT-6 has high homology with three other strains of the Dactylonectria genus. AntiSMASH analysis displayed 45 secondary metabolite biosynthetic gene clusters (BGCs) in D. alcacerensis CT-6, and most of them were unknown and yet to be unveiled. Furthermore, only six known substances had been isolated from the fermented products of D. alcacerensis CT-6, suggesting that a great number of cryptic BGCs in D. alcacerensis CT-6 are silent and/or expressed at low levels under conventional conditions. Therefore, our study provides an important basis for further chemical study of D. alcacerensis CT-6 using the gene-mining strategy to awaken these cryptic BGCs for the production of bioactive secondary metabolites.

Comparative Analysis of Glucosinolate and Phenolic Compounds in Green and Red Kimchi Cabbage (Brassica rapa L. ssp. pekinensis) Hairy Roots after Exposure to Light and Dark Conditions

Brassica rapa L. ssp. pekinensis (Lour.) Hanelt (kimchi cabbage) is a major vegetable cultivated in Korea, and its hairy roots (HRs) are rich in glucosinolates and phenolic compounds. This study aimed to induce HRs from cotyledon explants via the transformation of the Agroacterium rhizogenes strain R1000 and examine the glucosinolate and phenolic compounds present in the HRs of two kimchi cabbage (green and red) cultivars after exposure to 16 h light/8 h dark conditions (photosynthetic photon flux density of 54.6 µmol m−2 s−1) and continuous dark conditions. The highest HR production was achieved in the green kimchi cabbage grown under dark conditions (0.37 ± 0.01 DW g/30 mL). The highest glucosinolate and phenolic contents were neoglucobrassicin and catechin hydrate, which were highest in the green kimchi HRs grown under dark (GKHD) conditions (5268.29 ± 292.84 µg/g DW) and green HRs grown under light (GKHL) conditions (203.49 ± 4.70 µg/g DW), respectively. A heat map showed that the red kimchi HRs grown under dark conditions (RKHD) and the GKHL condition accumulated the highest glucosinolate and phenolic contents. Principal component (PCA) and partial least-squares discriminant (PLS-DA) analyses of the 13 identified metabolites showed a clear separation. According to a variable importance in projection (VIP) analysis, quercetin was the most important metabolite, leading to a clear separation. The most suitable conditions for enhancing the glucosinolate and phenolic contents were the GKHD and GKHL conditions, respectively, whereas both compounds were enhanced in the RKHD condition. HRs cultures cultivated under light and dark conditions are a promising method to enhance the production of specific health-promoting bioactive metabolites, which might be helpful in the pharmaceutical and nutraceutical industries.

Simulate the Dynamic Interactions Across Nutritional Supplements, the Polybiome, and the Biochemical Approach Dependent on Patient-Derived Gastrointestinal Knowledge

Dietary and lifestyle planning decisions, dysbiosis in the composition of the microbial community and the production of bioactive metabolites by the gastrointestinal microbiota are all factors that have a significant influence on the mucosal integrity of the intestines and the progression of diseases like colon cancer.

Occurrence of aetokthonotoxin producer in natural samples – A PCR protocol for easy detection

Cyanobacteria are well known producers of bioactive metabolites, including harmful substances. The recently discovered “eagle killer” neurotoxin aetokthonotoxin (AETX) is produced by the epiphytic cyanobacterium Aetokthonos hydrillicola growing on invasive water thyme (Hydrilla verticillata). The biosynthetic gene cluster of AETX was previously identified from an Aetokthonos strain isolated from the J. Strom Thurmond Reservoir, Georgia, USA. Here, a PCR protocol for easy detection of AETX-producers in environmental samples of plant-cyanobacterium consortia was designed and tested. Three different loci of the AETX gene cluster were amplified to confirm the genetic potential for AETX production, along with two variable types of rRNA ITS regions to confirm the homogeneity of the producer´s taxonomic identity. In samples of Hydrilla from three Aetokthonos-positive reservoirs and one Aetokthonos-negative lake, the PCR of all four loci provided results congruent with the Aetokthonos presence/absence detected by light and fluorescence microscopy. The production of AETX in the Aetokthonos-positive samples was confirmed using LC-MS. Intriguingly, in J. Strom Thurmond Reservoir, recently Hydrilla free, an Aetokthonos-like cyanobacterium was found growing on American water-willow (Justicia americana). Those specimens were positive for all three aet markers but contained only minute amounts of AETX. The obtained genetic information (ITS rRNA sequence) and morphology of the novel Aetokthonos distinguished it from all the Hydrilla-hosted A. hydrillicola, likely at the species level. Our results suggest that the toxigenic Aetokthonos spp. can colonize a broader array of aquatic plants, however the level of accumulation of the toxin may be driven by host-specific interactions such as the locally hyper-accumulated bromide in Hydrilla.

Spectrophotometric analysis of bioactive metabolites and fermentation optimisation of Streptomyces sp. HU2014 with antifungal potential against Rhizoctonia solani

Streptomyces spp. produce a range of secondary metabolites that can inhibit phytopathogen growth. This study aimed to optimise the environmental and nutritional parameters for improving the production of antifungal components by Streptomyces sp. HU2014 through statistical approaches. Spectrophotometry and bioassay revealed that two fractions, F6 and F8, from the cell-free filtrates of HU2014 culture broth were rich in antifungal compounds. Subsequently, single-factor experiments were conducted using glucose-peptone-yeast extract medium as basal medium, and the effects of different parameters on the production of bioactive metabolites by Streptomyces sp. HU2014 were evaluated and optimised using shake-flask experiments as follows: incubation time, 10 days; temperature, 25 °C; agitation speed, 150 rpm; inoculum size, 5% (v/v); initial pH, 7.0; and medium composition, dextrin, yeast extract and KNO3. The central composite face-centred design from response surface methodology predicted 39.6 g/L dextrin, 8.5 g/L yeast extract and 2.5 g/L KNO3 as the optimum medium composition. The validation experiment confirmed that a 50-fold dilution of the optimised filtered fermentation broth of the strain culture showed an increase of 14.9% in the inhibition of Rhizoctonia solani YL-3 when compared with the basal medium. A good correlation between measured and predicted values of the model validated both the responses. Thus, the present study used statistical optimisation to improve the bioactive metabolites productivity in Streptomyces sp. HU2014.

Micropropagation and elicited production of triterpenoid saponin glycosides and stigmasterol via precursor and elicitor feeding in Bacopa floribunda (R.Br.) Wettst.-A potential nootropic herb.

Bacopa floribunda (Family: Plantaginaceae) is used in folklore medicines for the management of cognitive dysfunction. It has nootropic, antiaging, anti-inflammatory, anti-cholinesterase, and antioxidant properties. We developed an efficient and reproducible protocol for in vitro propagation of B. floribunda using the nodal explants. We assessed the effects of Murashige and Skoog (MS) medium fortified with various plant growth regulatory substances (PGRs), a precursor, and elicitors and their optimal combinations on regeneration and production of total saponins, triterpenoid saponin glycosides (bacoside A3, bacopaside X, bacopaside II, and bacosaponin C), and stigmasterol content in in vitro grown biomass of B. floribunda. The growth of the shoots and roots was stimulated by MS + 2.0 mg/l BAP + 2.0 mg/l KIN and MS + 0.5 mg/l IAA + 0.5 mg/l IBA + 1.0 mg/l NAA, respectively. After 10 weeks of acclimatization, plantlets of B. floribunda had a survival rate of 95%. The highest total saponin content (35.95 ± 0.022 mg DE/g DW) was noted in the treatment of MS + 2.0 mg/l BAP + 1.5 μM SQ. Similarly, total triterpenoid saponin glycosides and stigmasterol were found maximum in biomass derived from MS + 2.0 mg/l BAP + 1.5 μM SQ and MS + 2.0 mg/l BAP, respectively. At the same treatments, bacoside A3 (1.01 ± 0.195 mg/g DW), bacopaside II (43.62 ± 0.657 mg/g DW), bacopaside X (1.23 ± 0.570 mg/g DW), bacosaponin C (0.19 ± 0.195 mg/g DW), and stigmasterol (7.69 ± 0.102 mg/g DW) were reported. The present findings will help to highlight B. floribunda as a potent memory-enhancing herb, and in future also, it could be a potential substitute to B. monnieri. The current work is the first to describe the micropropagation and the elicited production of bioactive metabolites from the in vitro grown biomass of B. floribunda. In addition, further research is needed on production of bioactives, their pharmacological effects, and the elicited production using callus, cell suspension, and hairy root cultures.

In vitro bioactive metabolite production and plant regeneration of medicinal plant Angelica sinensis

The root of Angelica sinensis (Oliv.) Diels is a traditional Chinese medicine (TCM) widely used for the cardio-cerebrovascular, anti-inflammatory, and anti-cancer agents, etc. Currently, the root yield is mainly limited by narrow geographical distribution, early bolting and flowering (EBF), continuous cropping obstacle, and germplasm degeneration. While two ancillary strategies to produce bioactive metabolites by bioreactor and innovate new germplasms by genome editing have not been conducted. Here is reported embryogenic callus induction, histomorphological structure identification, suspension cell culture, bioactive metabolite determination, shoot bud and root differentiation, and plantlet acclimatization at different treatments such as explants, hormones, and culture conditions. The embryogenic calli can be effectively induced (99.0%) from the root of aseptic seedlings by a combination of 2.0 mg/L IBA and 0.2 mg/L KT, and embryogenic cells including: three-cell, globular-, heart-, torpedo-, and cotyledon-shaped embryos were observed. The maximum growth rate, bioactive metabolites contents (i.e., ferulic acid, soluble sugar, flavonoids, and phenolic), and antioxidant capacities were observed at 9–12 d with inoculum density 40 g/L, 22 ℃ and 16/8 h light/dark. Robust plantlets can be obtained within 180 d after successive shoot bud and root differentiation as well as plantlet acclimation. Based on the strategies for the satisfaction of root demand, an effective and complete scheme is proposed for producing bioactive metabolites and regenerating plant of A. sinensis.

Investigation of Secondary Metabolites from Marine‐Derived FungiAspergillus

AbstractMarine fungiAspergillus flavipesandA. terreuswere investigated for secondary metabolites using electrospray ionization‐quadrupole time‐of‐flight mass spectrometry (ESI‐QTOF MS) analysis. The ESI‐MS analysis showed thatA. flavipesshowed molecular ion peaks for compounds, terrein(1), butyrolactone I(2), butyrolactone I‐carboxylic acid(3), butyrolactone III(4), while,A. terreushad additional presence of new compound aspernolide Q(5)with absence of compound(3). By using tandem mass spectrometry data, the prominent fragment ions helped in the establishing the structure of compounds(2‐5). Further, chemical transformation of butyrolactone I to butyrolactone III and aspernolide Q were carried out followed by NMR analysis which strongly suggested their structures. The evaluation of salt stress experiment ofA. terreusculture medium affected the production of major bioactive metabolites, terrein and butyrolactone I(2). The HPLC analysis showed that culture produces high amount of terrein at 35 ‰, while, maximum production of butyrolactone I was observed in fresh water i. e. 0‰. The study highlighted an importance of salinity in producing these metabolites where, terrein and butyrolactone I could be produced in equal ratio at 18‰. Importantly, we have demonstrated that using this fungal strain and by growing in medium at specific salinity could be way forward for commercial production of these bioactive compounds.

Exogenous melatonin enhances the growth and production of bioactive metabolites in Lemna aequinoctialis culture by modulating metabolic and lipidomic profiles

BackgroundLemna species are cosmopolitan floating plants that have great application potential in the food/feed, pharmaceutical, phytoremediation, biofuel, and bioplastic industries. In this study, the effects of exogenous melatonin (0.1, 1, and 10 µM) on the growth and production of various bioactive metabolites and intact lipid species were investigated in Lemna aequinoctialis culture.ResultsMelatonin treatment significantly enhanced the growth (total dry weight) of the Lemna aequinoctialis culture. Melatonin treatment also increased cellular production of metabolites including β-alanine, ascorbic acid, aspartic acid, citric acid, chlorophyll, glutamic acid, phytosterols, serotonin, and sucrose, and intact lipid species; digalactosyldiacylglycerols, monogalactosyldiacylglycerols, phosphatidylinositols, and sulfoquinovosyldiacylglycerols. Among those metabolites, the productivity of campesterol (1.79 mg/L) and stigmasterol (10.94 mg/L) were the highest at day 28, when 10 µM melatonin was treated at day 7.ConclusionThese results suggest that melatonin treatment could be employed for enhanced production of biomass or various bioactive metabolites and intact lipid species in large-scale L. aequinoctialis cultivation as a resource for food, feed, and pharmaceutical industries.

Endophytic microbes and their diverse beneficial aspects in various sectors: A critical insight

Endophytes are ubiquitous and grow in plant tissues without causing any harmful effects to the host. They include different groups of microorganisms such as bacteria, fungi and actinomycetes. Along with the host plants, the existing endophytes also co-evolve after a long relationship between them. Host plant-endophyte interaction is similar to that of plant growth promoting microbes as they induce the growth of the host plant and increase resilience against biotic and abiotic stresses. The interaction of plant endophytes at the molecular level and the effect of endophytes on host gene expression is a new field of study and are still rarely explored. Endophytes act as a promising resource of many invaluable bioactive secondary metabolites. Some of these bioactive compounds include alkaloids, polyphenols, sterols, xanthones, terpenoids, flavones, coumarins, polyketides, quinones, saponins, tannins, benzopyrones, dibenzofurans. These secondary metabolites are beneficial for agriculture, industrial and pharmacological purposes. As endophytes have beneficial effects in sustainable agriculture, plant disease management, pharmaceuticals, industry and environmental management in an eco-friendly way, thus improving the strategy of application of endophytes as biological agents in every aspect of our life is a very challenging field of research. Our aim in this present review is to focus on plant-endophyte interactions and their various dimensions in order to address some future possibilities for expediting the bioactive secondary metabolite production.

Cold Plasma Treatment Increases Bioactive Metabolites in Oat (Avena sativa L.) Sprouts and Enhances In Vitro Osteogenic Activity of their Extracts

Cold plasma treatment has been studied to enhance the germination, growth, and bioactive phytochemical production in crops. Here, we aimed to investigate the effects of cold plasma treatment on the growth, bioactive metabolite production, and protein expression related to the physiological and osteogenic activities of oat sprouts. Oat seeds were soaked for 12 h, and then exposed to plasma for 6 min/day for 3 days after sowing. Plasma exposure did not significantly change the growth of oat sprouts; however, increased the content of bioactive metabolites. A single exposure for 6 min on the first day (T-1) increased the content of free amino acids (39.4%), γ-aminobutyric acid (53%), and avenacoside B (23%) compared to the control. Hexacosanol content was the highest in T-3 (6 min exposure on each day for 3 days), 28% higher than that in the control. Oat sprout extracts induced the phosphorylation of adenosine 5′-monophosphate-activated protein kinase and osteoblast differentiation was enhanced by increasing the alkaline phosphatase (ALP) activity; all these effects were induced by plasma treatment. Avenacoside B content was positively correlated with ALP activity (r = 0.911, p < 0.1). These results suggest that plasma treatment has the potential to improve the value of oat sprouts and that it may be used in food fortification to enhance nutritional value for promoting human health.

Valorization of Invasive Plant Extracts against the Bispecies Biofilm Staphylococcus aureus-Candida albicans by a Bioguided Molecular Networking Screening.

Invasive plants efficiently colonize non-native territories, suggesting a great production of bioactive metabolites which could be effective antibiofilm weapons. Our study aimed to look for original molecules able to inhibit bispecies biofilm formed by S. aureus and C. albicans. Extracts from five invasive macrophytes (Ludwigia peploides, Ludwigia grandiflora, Myriophyllum aquaticum, Lagarosiphon major and Egeria densa) were prepared and tested in vitro against 24 h old bispecies biofilms using a crystal violet staining (CVS) assay. The activities of the extracts reducing the biofilm total biomass by 50% or more were comparatively analyzed against each microbial species forming the biofilm by flow cytometry (FCM) and scanning electron microscopy. Extracts active against both species were fractionated. Obtained fractions were analyzed by UHPLC-MS/MS and evaluated by the CVS assay. Chemical and biological data were combined into a bioactivity-based molecular networking (BBMN) to identify active compounds. The aerial stem extract of L. grandiflora showed the highest antibiofilm activity (&gt;50% inhibition at 50 µg∙mL-1). The biological, chemical and BBMN investigations of its fractions highlighted nine ions correlated with the antibiofilm activity. The most correlated compound, identified as betulinic acid (BA), inhibited bispecies biofilms regardless of the three tested couples of strains (ATCC strains: &gt;40% inhibition, clinical isolates: ≈27% inhibition), confirming its antibiofilm interest.

Screening for agroactive and bioactive metabolites production by actinobacteria isolated from rhizospheric soils

Screening for agroactive and bioactive metabolites production by actinobacteria isolated from rhizospheric soils

Volatile Compounds in Actinomycete Communities: A New Tool for Biosynthetic Gene Cluster Activation, Cooperative Growth Promotion, and Drug Discovery.

The increasing appearance of multiresistant pathogens, as well as emerging diseases, has highlighted the need for new strategies to discover natural compounds that can be used as therapeutic alternatives, especially in the genus Streptomyces, which is one of the largest producers of bioactive metabolites. In recent years, the study of volatile compounds (VOCs) has raised interest because of the variety of their biological properties in addition to their involvement in cell communication. In this work, we analyze the implications of VOCs as mediating molecules capable of inducing the activation of biosynthetic pathways of bioactive compounds in surrounding Actinomycetes. For this purpose, several strains of Streptomyces were co-cultured in chamber devices that allowed VOC exchange while avoiding physical contact. In several of those strains, secondary metabolism was activated by VOCs emitted by companion strains, resulting in increased antibiotic production and synthesis of new VOCs. This study shows a novel strategy to exploit the metabolic potential of Actinomycetes as well as emphasizes the importance of studying the interactions between different microorganisms sharing the same ecological niche.

Natural products, including a new caboxamycin, from Streptomyces and other Actinobacteria isolated in Spain from storm clouds transported by Northern winds of Arctic origin.

Actinobacteria, mostly Streptomyces species, are the main source of natural products essential in medicine. While the majority of producer microorganisms of secondary metabolite are reported from terrestrial or marine environments, there are limited reports of their isolation from atmospheric precipitations. Clouds are considered as atmospheric oases for microorganisms and there is a recent paradigm shift whereby atmospheric-derived Actinobacteria emerge as an alternative source for drug discovery. In this context, we studied a total of 18 bioactive Actinobacteria strains, isolated by sampling nine precipitation events with prevailing Northern winds in the Cantabrian Sea coast, Northern Spain. Backward trajectories meteorological analyses indicate that air masses were originated mostly in the Arctic Ocean, and their trajectory to downwind areas involved the Atlantic Ocean and also terrestrial sources from continental Europe, and in some events from Canada, Greenland, Mauritania and Canary Islands. Taxonomic identification of the isolates, by 16S rRNA gene sequencing and phylogenetic analyses, revealed that they are members of three Actinobacteria genera. Fifteen of the isolates are Streptomyces species, thus increasing the number of bioactive species of this genus in the atmosphere to a 6.8% of the total currently validated species. In addition, two of the strains belong to the genus Micromonospora and one to genus Nocardiopsis. These findings reinforce a previous atmospheric dispersal model, extended herein to the genus Micromonospora. Production of bioactive secondary metabolites was screened in ethyl acetate extracts of the strains by LC-UV-MS and a total of 94 secondary metabolites were detected after LC/MS dereplication. Comparative analyses with natural products databases allowed the identification of 69 structurally diverse natural products with contrasted biological activities, mostly as antibiotics and antitumor agents, but also anti-inflammatory, antiviral, antiparasitic, immunosuppressant and neuroprotective among others. The molecular formulae of the 25 remaining compounds were determined by HRMS. None of these molecules had been previously reported in natural product databases indicating potentially novel metabolites. As a proof of concept, a new metabolite caboxamycin B (1) was isolated from the culture broth of Streptomyces sp. A-177 and its structure was determined by various spectrometric methods. To the best of our knowledge, this is the first novel natural product obtained from an atmospheric Streptomyces, thus pointing out precipitations as an innovative source for discovering new pharmaceutical natural products.

Evaluation of antibacterial potential of endophytic fungi and GC-MS profiling of metabolites from Talaromyces trachyspermus

• Endophytic fungi were isolated from different healthy wild and cultivated plants and identified. • Culture filtrate of most of the test endophytic fungi showed strong antibacterial activity in vitro. • Most effective isolates of endophytic fungi were further studied for characterization of their organic compounds. • Oily n -hexane extract from mycelium and n -hexane fraction of culture filtrates of endophytic fungus Talaromyces trachyspermus revealed the presence of several compounds. Microorganisms are essential for human life. Since time immemorial, every process on earth has been affected by an unending ability of microorganisms to renovate the world. From the last two decades, microbes residing inside plants have gained special attention, and are called endophytes. These microbes have natural potential for production of various bioactive secondary metabolites and can be directly or indirectly used as therapeutic agents against a plethora of maladies. For this purpose, endophytic fungi were isolated and identified from different healthy, wild and cultivated plants. They were tested against common laboratory bacteria ( Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella typhimurium, Bacillus subtilis and Escherichia coli) and they showed strong antibacterial activity against pathogenic bacteria. Most effective isolates of endophytic fungi were further studied for characterization of their organic compounds. Oily n -hexane extract from mycelium and n -hexane fraction of culture filtrates of endophytic fungus Talaromyces trachyspermus revealed the presence of several compounds. The identification of bioactive compounds by GC-MS (Gas Chromatography-Mass Spectrometry) is based on the molecular weights, peak areas, mass fragmentations and retention times. Most of these compounds have therapeutic properties and are used in the pharmaceutical field. The major bioactive compounds, eicosane, oleic Acid, n -hexadecanoic acid, ethyl Oleate, cis -vaccenic acid, heptacosane identified from T. trachyspermus have been reported to possess antioxidant, antibacterial, antifungal and nematicidal properties. These results will lead to further in-depth research towards the potential use of this endophytic fungus and their bio-constituents can be further isolated and used in therapeutic applications.

Endophytic Candida membranifaciens from Euphorbia milii L. Alleviate Salt Stress Damages in Maize

Fungal endophytes are not widely known for their role in bioactive metabolite production and salinity stress alleviation in different crop plants. Presently, we investigated the salt stress (NaCl, KCl, and H2SO4) mitigation capabilities of fungal endophyte Candida membranifaciens (FH15) isolated from Euphorbia milii L. The pure culture filtrate (CF) of C. membranifaciens revealed siderophore production and solubilization of phosphate, with high levels of indoleacetic acid (IAA: 35.8µg/mL), phenolics (70 µg/mL), and flavonoids (50 µg/mL) by using a UV spectrophotometer. The LC/MS analysis of the CF showed different phenols and flavonoids that were identified as Salicylic acid, Baicalein, Aconitic acid, Feruloylquinic acid, Coniferyl aldehyde hexoside, Pentose, Chlorogenic acid, Myricetin, Propoxyphene, and Amino-flunitrazepam. Inoculation of maize seedlings with C. membranifaciens significantly (p = 0.05) enhanced the fresh and dry biomass, carotenoid, and chlorophyll contents under 100 mM salt stress conditions. Similarly, the catalase, peroxidase activity, phenols, proline flavonoids and relative water contents (RWC) of the maize plants were enhanced. More interestingly, the inoculation of C. membranifaciens on maize revealed a higher endogenous IAA level as compared to non-inoculated control plants. Endophyte C. membranifaciens inoculation on maize seedlings under salt stress revealed a 20.87% and 16.60% increase in fresh and dry biomass, as well as significantly enhanced root shoot length and allied growth attributes, in addition to an alleviation of the adverse effects of salinity stress. Conclusively, endophytic C. membranifaciens significantly enhanced the growth attributes of maize and mitigated the adverse effects of salinity stress. Such endophytic fungal strain could be used for further field trails to enhance agricultural productivity and facilitate sustainable agricultural practices.

Improving artemisinin and essential oil production from Artemisia plant through in vivo elicitation with gamma irradiation nano-selenium and chitosan coupled with bio-organic fertilizers

Artemisia plants process potential bioactive secondary metabolites such as artemisinin and essential oil. They are useful in controlling potential pests and microbes and have a therapeutic effect. The commercial production of artemisinin and essential oil is limited to regarding the worldwide demand. Urgent attempts must be undertaken to improve the production of bioactive secondary metabolites. The objectives of this experiment were to increase the production and improve the quality of bioactive secondary metabolites in order to limit the use of agrochemicals. Therefore, a field experiment was conducted during the 2018 and 2019 seasons. Treatments included three elicitations (gamma irradiation, nano-selenium, and chitosan) and three kinds of fertilizers (NPK, Moringa leaf extract, and humic acid). The experiment was conducted as a factorial with a completely randomized block. The designs and treatments were arranged in a split–split plot with three replicates. A single application of elicitors showed that chitosan &amp;gt; nano-selenium, chitosan &amp;gt; gamma irradiation, and Moringa &amp;gt; humic acid &amp;gt; NPK in plants’ artemisinin and essential oil content, while the interaction showed a significant synergistic relationship between elicitors and the fertilizers in enhancing the quantity and quality of artemisinin and essential oil of Artemisia plants. Without using any pesticides, there was no infection that appeared in Artemisia plants, this could be due to the enhancement of bioactive secondary metabolite production.