Evaluation of Phoma sp. Biomass as an Endophytic Fungus for Synthesis of Extracellular Gold Nanoparticles with Antibacterial and Antifungal Properties.

The aim of our study was to examine the different concentrations of AuNPs as a new antimicrobial substance to control the pathogenic activity. The extracellular synthesis of AuNPs performed by using Phoma sp. as an endophytic fungus. Endophytic fungus was isolated from vascular tissue of peach trees (Prunus persica) from Baft, located in Kerman province, Iran. The UltraViolet-Visible Spectroscopy (UV-Vis spectroscopy) and Fourier transform infrared spectroscopy provided the absorbance peak at 526 nm, while the X-ray diffraction and transmission electron microscopy images released the formation of spherical AuNPs with sizes in the range of 10-100 nm. The findings of inhibition zone test of Au nanoparticles (AuNPs) showed a desirable antifungal and antibacterial activity against phytopathogens including Rhizoctonia solani AG1-IA (AG1-IA has been identified as the dominant anastomosis group) and Xanthomonas oryzae pv. oryzae. The highest inhibition level against sclerotia formation was 93% for AuNPs at a concentration of 80 µg/mL. Application of endophytic fungus biomass for synthesis of AuNPs is relatively inexpensive, single step and environmentally friendly. In vitro study of the antifungal activity of AuNPs at concentrations of 10, 20, 40 and 80 µg/mL was conducted against rice fungal pathogen R. solani to reduce sclerotia formation. The experimental data revealed that the Inhibition rate (RH) for sclerotia formation was (15, 33, 74 and 93%), respectively, for their corresponding AuNPs concentrations (10, 20, 40 and 80 µg/mL). Our findings obviously indicated that the RH strongly depend on AuNPs rates, and enhance upon an increase in AuNPs rates. The application of endophytic fungi biomass for green synthesis is our future goal.

Antioxidant epoxydon and benzolactone derivatives from the insect-associated fungus Phoma sp.

One new epoxydon ester (1) and a new benzolactone derivative (2), along with four known compounds (3-6), were isolated from the insect-associated fungus Phoma sp. Their structures were confirmed by extensive MS and NMR spectroscopic analysis and their absolute configurations were determined by a combination of modified Mosher method and Mo2(OCOCH3)4-induced electronic circular dichroism (ECD) experiments. Compounds 1 and 5 were revealed to have potent antioxidant activities, which were approximate to the potency of the positive control trolox. In addition, 1 also exhibited moderate cytotoxic effect against human MGC-803 tumor cell line.[Formula: see text].

Identification of the gene cluster for bistropolone-humulene meroterpenoid biosynthesis in Phoma sp.

Eupenifeldin, a bistropolone meroterpenoid, was first discovered as an antitumor agent from the fungus Eupenicillium brefeldianum. We also isolated this compound and a new congener from a strain of Phoma sp. (CGMCC 10481), and evaluated their antitumor effects. Eupenifeldin showed potent in vitro anti-glioma activity. This tropolone-humulene-tropolone meroterpenoid could be originated from two units of tropolone orthoquinone methides and a 10-hydroxyhumulene moiety via hetero-Diels-Alder reactions. To explore the biosynthesis of this class of tropolonic sesquiterpenes, the genome of a eupenifeldin-producing Phoma sp. was sequenced and analyzed. The biosynthetic gene cluster of eupenifeldin (eup) was identified and partially validated by genomic analysis, gene disruption, and product analysis. A nonreducing polyketide synthase EupA, a FAD-dependent monooxygenase EupB, and a non-heme Fe (II)-dependent dioxygenase EupC, were identified as the enzymes responsible for tropolone formation. While the terpene cyclase EupE of an unknown family was characterized to catalyze humulene formation, and a cytochrome P450 enzyme EupD was responsible for hydroxylation of humulene. This study sheds light on the biosynthesis of eupenifeldin, and paves the way to further decipher its biosynthetic pathway.

Investigating the antifungal activity and mechanism of a microbial pesticide Shenqinmycin against Phoma sp.

Tea white scab (TWS) is a major disease affecting tea trees in mid-elevation regions and often occurs during rainy seasons with low temperatures. This disease is caused by the fungal pathogen Phoma sp. TWS can infect young stems, tender leaves, and tender shoots and lead to the production of low-quality tea. Owing to the absence of an effective control, TWS can result in substantial loss in tea production. In this study, we isolated and identified the pathogen from tea leaves infected by TWS and then evaluated in vitro the antifungal activity of Shenqinmycin, polyoxin, azoxystrobin, oligosaccharins, and tebuconazole against Phoma sp. Our results indicated that Shenqinmycin can inhibit the growth of Phoma sp. mycelia, with the EC50 value of 0.74µg/mL. After Phoma sp. being incubated in PDB liquid medium with Shenqinmycin, its mycelia were distorted and distended at 1.56µg/mL of minimum inhibitory concentration for 6h. Crucial genes associated with cell redox homeostasis, proteins synthesis, energy metabolism, and cytoskeleton were studied at mRNA and protein levels through RT-qPCR and Nano-LC-MS/MS. The results showed that the genes of 3-phosphate-glyceraldehyde dehydrogenase, citrate synthase, NADH-ubiquinone oxidoreductase subunit (NADH-subunit), ribosomal protein, eukaryotic initiation factor 4A-I, ß-tubulin, and α-tubulin were up-regulated. Meanwhile, the genes of formate dehydrogenase (FDH), malate dehydrogenase, mitochondrial heat shock protein, and protein disulfide-isomerase (PDI) were up-regulated at mRNA level but down-regulated at protein level. These results indicated that Shenqinmycin contribute to cell redox homeostasis by up- or down-regulating NADH-subunit, FDH, and PDI.

α-Pyrone derivatives with cytotoxic activities, from the endophytic fungus Phoma sp. YN02-P-3.

Four new α-pyrone derivatives phomones C-F (1-4) together with four known compounds (5-8) were isolated from the endophytic fungus Phoma sp. YN02-P-3. Compound 1 is the first example of 6-α,ß-unsaturated ester-2-pyrone dimers via intermolecular symmetrical [2+2] cycloaddition. The chemical structures of these compounds were determined from spectroscopic data (1D/2D NMR, MS and IR). The acetylated product (9) of 1 along with compounds 1-8 were then tested for their cytotoxicity against HL-60, PC-3 and HCT-116 cell lines. Compounds 2, 3, 5 and 9 with acetyl groups showed significant inhibitory activities against the three cell lines with IC50 values in the range 0.52-9.85µM. while compounds 1, 4 and 6-8 that possess no acetyl group showed no inhibitory activity (IC50>50µM), indicating that the acetyl group at 10- or 12- are essential for their cytotoxic activities. The structure-activity relationships of these phomones were also reported.

An epigenetic modifier induces production of (10'S)-verruculide B, an inhibitor of protein tyrosine phosphatases by Phoma sp. nov. LG0217, a fungal endophyte of Parkinsonia microphylla.

Incorporation of the histone deacetylase (HDAC) inhibitor, suberoylanilide hydroxamic acid (SAHA), to a culture broth of the endophytic fungus Phoma sp. nov. LG0217 isolated from Parkinsonia microphylla changed its metabolite profile and resulted in the production of (10'S)-verruculide B (1), vermistatin (2) and dihydrovermistatin (3). When cultured in the absence of the epigenetic modifier, it produced a new metabolite, (S,Z)-5-(3',4'-dihydroxybutyldiene)-3-propylfuran-2(5H)-one (4) together with nafuredin (5). The structure of 4 was elucidated by spectroscopic analyses and its absolute configuration was determined by application of the modified Mosher's ester method. The absolute structure of (10'S)-verruculide B was determined as 5-[(10'S,2'E,6'E)-10',11'-dihydroxy-3',7',11'-trimethyldodeca-2',6'-dien-1'-yl]-(3R)-6,8-dihydroxy-3-methylisochroman-1-one (1) with the help of CD and NOE data. Compound 1 inhibited the activity of protein tyrosine phosphatases (PTPs) 1B (PTP1B), Src homology 2-containing PTP 1 (SHP1) and T-cell PTP (TCPTP) with IC50 values of 13.7±3.4, 8.8±0.6, and 16.6±3.8µM, respectively. Significance of these activities and observed modest selectivity of 1 for SHP1 over PTP1B and TCPTP is discussed.

Bioactive Diphenyl Ethers and Isocoumarin Derivatives from a Gorgonian-Derived Fungus Phoma sp. (TA07-1).

Three new diphenyl ether derivatives-phomaethers A-C (1-3) and five known compounds-including a diphenyl ether analog, 2,3'-dihydroxy-4-methoxy-5',6-dimethyl diphenyl ether (4); and four isocoumarin derivatives, diaportinol (5), desmethyldiaportinol (6), citreoisocoumarinol (7), and citreoisocoumarin (8)-were isolated from a gorgonian-derived fungus Phoma sp. (TA07-1). Their structures were elucidated by extensive spectroscopic investigation. The absolute configurations of 1 and 2 were determined by acid hydrolysis reactions. It was the first report to discover the diphenyl glycoside derivatives from coral-derived fungi. Compounds 1, 3, and 4 showed selective strong antibacterial activity against five pathogenic bacteria with the minimum inhibiting concentration (MIC) values and minimum bactericidal concentration (MBC) values between 0.156 and 10.0 µM.

A novel 3,4-dihydronaphthalen-1(2H)-one with spiro-butyrolactone and a new isocoumarin isolated from the endophytic fungus Phoma sp. YN02-P-3.

A novel 3,4-dihydronaphthalen-1(2H)-one with spiro-butyrolactone phomol (1) and a new isocoumarin phomasatin (2), together with two known compounds (3-4) were isolated from the solid culture of the endophytic fungus Phoma sp. YN02-P-3. Their structures including the absolute configurations were characterized on the basis of extensive 1D, 2D NMR (HSQC, HMBC, NOESY), MS, and CD spectral data. Compound 1 showed selective cytotoxic activity against HL-60 cell line with the IC50 value of 29.05 µM.

Cytochalasin derivatives from a jellyfish-derived fungus Phoma sp.

Four new cytochalasin derivatives (1-4), together with proxiphomin (5), were isolated from a jellyfish-derived fungus Phoma sp. The planar structures and relative stereochemistry were established by analysis of 1D and 2D NMR data. The absolute configuration was defined by the modified Mosher's method. The compounds showed moderate cytotoxicity against a small panel of human solid tumor cell lines (A549, KB, and HCT116).

Draft genome sequence of the endophytic fungus Phoma sp. strain YAFEF320, isolated from Gerbera jamesonii.

Here, we report a draft genome sequence of endophytic fungus Phoma sp. strain YAFEF320, isolated from the roots of Gerbera jamesonii. The genome size of Phoma sp. YAFEF320 was 32,542,820 bp with 52.08% GC content. The genome resource will support future research into potential secondary metabolite diversity of this fungus.

Fungal polyketides produced by an endophytic fungus Phoma sp. associated with Gastrodia elata.

Two novel fungal polyketides, phometides A (1) and B (2), together with four known compounds (3-6), were isolated from the endophytic fungus Phoma sp. YUD17001 obtained from Gastrodia elata Blume. The structures were elucidated based on spectroscopic analyses, X-ray crystal diffraction, and time-dependent density functional theory/electronic circular dichroism (TDDFT/ECD) calculations. Structurally, phometide A (1) represented the first example of C12 polyketide characterized by an unusual tetrahydrobenzofuran-3(2H)-one core with an α,ß-unsaturated ketone functionality, while phometide B (2) was an unprecedented molecule containing a 2-pentylcycloheptan-1-one scaffold. In an antimicrobial activity assay, phometide A (1) exhibited significant inhibitory activity against Staphylococcus aureus with MIC value of 4 µg/mL. Phometide B (2) showed moderate antifungal activity against Candida albicans with an MIC value of 16 µg/mL. Furthermore, compounds 1 and 2 were evaluated for their acetylcholinesterase inhibitory and cytotoxic activities.

Screening of different species of Phoma for the synthesis of silver nanoparticles.

We have screened 18 Phoma spp. for the mycosynthesis of silver nanoparticles (AgNPs). Out of 18, 17 Phoma spp. demonstrated mycosynthesis of AgNPs, which were characterized by UV-vis spectrophotometry, Fourier transform infrared, X-ray diffraction, transmission electron microscopy (TEM), scanning electron microscopy (SEM), nanoparticle tracking and analysis system, and zeta potential measurement. SEM and TEM analysis showed the mycosynthesis of polydispersed spherical AgNPs, with the exception by P. sorghina (MTCC-2096), which revealed the fabrication of silver nanorods. The effect of pH, temperature, silver nitrate, fungal filtrate, and light intensity was studied to understand the mechanism of mycosynthesis of AgNPs by P. sorghina. The involvement of protein was found during the mycosynthesis but the process failed to follow the Michaelis-Menton kinetics of the enzyme-catalyzed reaction. A three-step hypothetical mechanism, that is, activation, nucleation, and reduction, for the mycosynthesis of silver nanorods is proposed. The present study will be useful for the stable and rapid mycosynthesis of AgNPs. The extracellular process involved in synthesis of AgNPs was found to be rapid, simple, easy, and ecofriendly.

A new anti-proliferative compound from an endophytic fungus, Phoma sp.

A new oxazole-type compound (1), named macrooxazole E, and three known macrooxazoles A-C (2-4), were isolated from ethyl acetate (EtOAc) extracts of Phoma sp. JS0228 cultures, an endophytic fungus of Morus alba (M. alba). Structures of the isolated compounds were determined using spectroscopic methods, such as 1 D- and 2 D-nuclear magnetic resonance (NMR) and high-resolution mass spectrometry (HRMS). Macrooxazole E (1) differed from macrooxazole C only in the presence of methyl carboxylate instead of free carboxylic acid. Macrooxazole C showed moderate anti-proliferative activities against human breast cancer (MCF-7) and prostate cancer (LNCaP) cell lines with IC50 values of 0.29 mM and 0.36 mM, respectively. This study presents the possibility of the endophytic fungus Phoma sp. JS0228 to produce new bioactive natural compounds.

Soil Fungi as Biomediator in Silver Nanoparticles Formation and Antimicrobial Efficacy.

Introduction and Objectives: Biogenic agents in nanoparticles fabrication are gaining great interest due to their lower possible negative environmental impacts. The present study aimed to isolate fungal strains from deserts in Saudi Arabia and assess their ability in silver nanoparticles (AgNPs) fabrication and evaluate their antibacterial effect. Methods: Soil fungi were identified using 18s rDNA, and their ability in NPs fabrication was assessed as extracellular synthesis, then UV-vis spectroscopy, dynamic light scattering (DLS), energy-dispersive X-ray spectroscopy, and transmission electron microscopy were used for AgNPs characterization. The antibacterial activity of fungal-based NPs was assessed against one Gram-positive methicillin-resistant S. aureus (MRSA) and three Gram-negative bacteria (E. coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae). Ultrastructural changes caused by fungal-based NPs on K. pneumoniae were investigated using TEM along with SDS-PAGE for protein profile patterns. Results: The three fungal isolates were identified as Phoma sp. (MN995524), Chaetomium globosum (MN995493), and Chaetomium sp. (MN995550), and their filtrate reduced Ag ions into spherical P-AgNPs, G-AgNPs, and C-AgNPs, respectively. DLS data showed an average size between 12.26 and 70.24 nm, where EDX spectrums represent Ag at 3.0 keV peak. G-AgNPs displayed strong antibacterial activities against Klebsiella pneumoniae, and the ultrastructural changes caused by NPs were noted. Additionally, SDS-PAGE analysis of treated K. pneumoniae revealed fewer bands compared to control, which could be related to protein degradation. Conclusion: Present findings have consequently developed an eco-friendly approach in NPs formation by environmentally isolated fungal strains to yield NPs as antibacterial agents.

Pyranone Derivatives With Antitumor Activities, From the Endophytic Fungus Phoma sp. YN02-P-3.

Two new pyranone derivatives phomapyrone A (2) and phomapyrone B (3), one new coumarin 11S, 13R-(+)-phomacumarin A (1), three known pyranones (4-6), together with three known amide alkaloids fuscoatramides A-C (7-9), as well as 9S, 11R-(+)-ascosalitoxin (10) were isolated from the endophytic fungus Phoma sp. YN02-P-3, which was isolated from the healthy leaf tissue of a Paulownia tree in Yunnan Province, China. Their structures were elucidated using extensive NMR spectroscopic and HRESIMS data and by comparing the information with literature data. In addition, all compounds were tested for their cytotoxicity activity against human tumor cell lines, and the results showed that new compounds 1-3 showed moderate inhibitory activity against the HL-60 cell line with IC50 values of 31.02, 34.62, and 27.90 µM, respectively.

Suppression of Pseudomonas syringae pv. tomato infection by rhizosphere fungi.

BACKGROUND: Induced resistance against several plant pathogens was reported using different beneficial plant growth-promoting microorganisms. The potential of five fungal isolates, Trichoderma harzianum GT 3-2, Fusarium equiseti GF 18-3, F. equiseti GF 19-1, Phoma sp. GS 10-1 and Phoma sp. GS 14-1, to stimulate tomato growth and resistance against bacterial speck disease caused by Pseudomonas syringae pathovar (pv.) tomato DC3000 was evaluated. RESULTS: Based on the results of disease severity and growth promotion experiments, GF 18-3 exhibited the best results among all fungal isolates. Treatment with barley grain inocula (BGI) and culture filtrate (CF) of the isolates promoted tomato growth and suppressed the pathogen in pot trials. Furthermore, expressions of the pathogenesis-related genes (PR-1, ß-1,3-glucanase A, ß-1,3-glucanase B and LOX) were relatively higher than the control in the leaves of tomato plants treated with both BGI and CF. The transcription levels remained consistently higher than the control plants for 6 days post-inoculation with pathogen. CONCLUSION: Taken together, the results indicate that the tested fungal isolates have the potential to promote tomato growth and induce systemic resistance against the bacterial speck disease. Analysis of certain PR gene expression revealed significant activation in both BGI and CF treatments, leading to stimulated resistance against the pathogen. © 2021 Society of Chemical Industry.

Systemic resistance induced by Phoma sp. GS8-3 and nanosilica against Cucumber mosaic virus.

Cucumber mosaic virus (CMV) is a very serious hazard to vegetable production worldwide. This study is focused on evaluation of resistance stimulated by the plant growth-promoting fungus, Phoma sp. GS8-3, or nanosilica against CMV under pot and field conditions. The specific aim was to illustrate the mechanism of resistance stimulated by GS8-3 against CMV using microarray technology. Treatments with GS8-3 as well as nanosilica significantly decreased CMV severity and titer in tobacco and cucumber under pot and field conditions, respectively. Growth characters of tobacco and cucumber were significantly increased due to GS8-3 inoculation followed by nanosilica compared with control and BTH treatments. Microarray results showed highly upregulation of defense-related genes expression specially those related to heat shock proteins. Therefore, GS8-3 as well as nanosilica is suitable to serve as effective inducers against CMV in cucumber plants.

Rare Persistent Corneal Infection by Phoma sp. - A Case Report.

We report a case of severe Phoma sp. corneal infection in a middle-aged, otherwise healthy, female patient who was using a soft contact lens. This is the first time that such an infection has been reported in Greece. Our case demonstrates the clinical difficulties and management challenges presented by these recalcitrant corneal infections. Management steps included corneal grafting, vitrectomy, and intravitreal antibiotics.

Potentiality of the Phoma sp. inactive fungal biomass, a waste from the bioherbicide production, for the treatment of colored effluents.

The potentiality of Phoma sp. inactive fungal biomass, waste from the bioherbicide production, was evaluated for the treatment of colored effluents containing Acid Red 18 (AR 18) dye. The batch experiments were performed to evaluate the following parameters: pH of the solution (2-10), dye concentration (50-200 mg L-1), adsorbent dose (0.5-2.5 g L-1), contact time (0-180 min) and temperature (298-328 K). The batch experiments using a synthetic dye solution revealed that Phoma sp. was efficient at pH of 2.0, 298 K and using a dosage of 1.25 g L-1. The process was fast, being the equilibrium reached within 180 min. The maximum value of biosorption capacity was 63.58 mg g-1, being the process favorable and exothermic. From the fixed bed assays, breakthrough curves were obtained, presenting a mass transfer zone of 7.08 cm and breakthrough time of 443 min. Phoma sp. was efficient to decolorize a simulated effluent, removing more than 90% of the color. From the obtained results, it can be concluded that Phoma sp. inactive biomass is a low-cost option to treat colored effluents in continuous and discontinuous biosorption modes. These indicate that Phoma sp. of inactive biomass is an option for the treatment of colored effluents.

Bioactive polyketides from the mangrove endophytic fungi Phoma sp. SYSU-SK-7.

Five new polyketides, colletotric B (2), 3-hydroxy-5-methoxy-2,4,6-trimethylbenzoic acid (3), colletotric C (4), chaetochromone D (6) and 8-hydroxy-pregaliellalactone B (9), together with four known analogues (1, 5 and 7-8) were isolated from the mangrove endophytic fungus Phoma sp. SYSU-SK-7. Their structures were elucidated by analysis of extensive spectroscopic data and mass spectrometric data. Compounds 1-2 showed strong antimicrobial activity against the P. aeruginosa, MRSA and C. albicans with the MIC values in the range of 1.67-6.28 µg/ml. Furthermore, Compounds 1-5 also exhibited significant α-glucosidase inhibitory activity with the IC50 values in the range of 36.2-90.6 µM. Compound 7 was found to inhibited radical scavenging activity against DPPH with the EC50 value of 11.8 µM.