Fusarium Chlamydosporum Research Articles

Molecular Characterization of Endophytic Fungal Strains for Green Synthesis of ZnO and Au Nanoparticles

Abstract Introduction/Objective Introduction: Traditional methods for nanoparticle synthesis often involve hazardous compounds, posing environmental risks and limiting their biomedical applications due to instability. The exploration of green synthesis approaches using natural products and eco-friendly solvents presents a challenging yet imperative pursuit in nanoparticle research. Methods/Case Report Methods: Endophytic fungi were isolated from healthy Eucalyptus sideroxylon plants collected from the Desert Research Center. Cultivation of fungi in malt extract broth was conducted at 28°C with agitation for 96 hours. Subsequently, fungal DNA was extracted, and ITS-rDNA regions were PCR-amplified for identification. Sequencing and phylogenetic analysis were performed to characterize the fungal isolates. Fungal filtrates were utilized for the biosynthesis of ZnO and Au nanoparticles (NPs) from ZnSO4 and HAuCl4 solutions, respectively. Results (if a Case Study enter NA) Results: Among the 13 fungal isolates, Fusarium chlamydosporum (FI-03) exhibited the most efficient synthesis of ZnO and Au NPs. Sequencing confirmed the identity of the fungal strain. The synthesized NPs displayed uniform spherical shapes, with ZnO NPs averaging 19.3 nm and Au NPs averaging 22.1 nm in size. Transmission electron microscopy (TEM) analysis further elucidated the morphology of the NPs. Conclusion Conclusion: Fusarium chlamydosporum emerged as a promising candidate for the green synthesis of ZnO and Au NPs. This environmentally friendly approach offers a cost-effective and biocompatible alternative to conventional nanoparticle synthesis methods.

Trichoderma produces methyl jasmonate-rich metabolites in the presence of Fusarium, showing biostimulant activity and wilt resistance in tomatoes

Bioactive secondary metabolites from fungi, including Trichoderma, are an excellent source of plant biostimulants. Although production of novel biostimulants from known microbes is critical, challenging them may produce novel bioactive compounds. With this hypothesis, the study used live Fusarium chlamydosporum (FOL7) culture as the inducer during T. harzianum (IF63) growth in broth. Plate assays and gas chromatography-mass spectrometry (GC-MS) analysis were used to characterise the metabolites. Microscopy, pot experiments and, biochemical estimations of the defence-related enzymes in tomato plants established the biostimulant activity of the induced Trichoderma metabolites. Fungal crude metabolites (FCM) obtained from IF63+FOL7 extracts (TF.ex) showed increased antimicrobial activity. TF.ex at 50 μg mL−1, inhibited the FOL7 growth by 68.33% compared to the Trichoderma alone extract. Scanning electron microscopy (SEM) revealed morphological disruption of FOL7 mycelia by TF.ex. GC-MS analysis of the extracts revealed the presence of approximately 64 compounds, of which at least 13 were detected explicitly in TF.ex. Methyl (3-oxo-2-pentylcyclopentyl) acetate (Methyl dihydrojasmonate), a lipid functionally related to jasmonic acid, was the major metabolite (∼21%) present in TF.ex. Tomato seed dressing with TF.ex promoted plant growth and induced systemic resistance against FOL7 compared to alone Trichoderma and Fusarium extracts. The TF.ex treatment increased the superoxide dismutase (33%) and catalase activity by 2.5-fold in tomato plants. The study concludes that fungal secondary metabolites may be modulated by providing appropriate challenges to produce effective metabolite-based biostimulants for agricultural applications.

Management of Fusarium fruit rot of Luffa cylindrical caused by Fusarium incarnatum and Fusarium chlamydosporum

Fusarium rot of Luffa cylindrical was detected at Kafr-El-Dawar province, Beheira governorate, North Egypt during the growing season 2021. Surveyed disease incidence at Beheira, Kafr El-Shekh and Sharkia governorate showed fruit rot incidences of 18.33%, 16.12%, and 12.42%, respectively. Two fungal isolates of Fusarium spp. were tested for their pathogenic ability to induce Fusarium rot disease and typical disease symptoms. The online Basic Local Alignment Search Tool for Nucleotide Sequences (BLASTN) was used for identification and confirmation of identity performance of Internal Transcribed Spacer (ITS) and DNA sequencing, then compared with sequences available in GenBank. The two fungal isolates were identified as Fusarium incarnatum and Fusarium chlamydosporum and registered under accession number MN480497 and MN480498, respectively. Under laboratory conditions, organic acids, essential oils and organic salts significantly inhibited the growth of the two fungal isolates. Complete inhibition of fungal growth (100%) was recorded at 0.75 g/l of Topsin-M70 (Thiophanate-methyl) and 0.5% of salicylic acid. Meanwhile, a moderate growth reduction was observed using benzoic acid, coumarine, and cinnamon, thyme oil and garlic oil treatments. Under field conditions for two successive seasons, similar trends were observed. Foliar sprays with the fungicide Topsin-M70 showed the largest reduction in disease expression. The highest fruit rot disease reduction was recorded for salicylic acid and coumarin treatments followed by thyme oil, benzoic acid and potassium carbonate, garlic oil, boric acid and sodium bicarbonate. We concluded that the treatments are effective, safe and cost-effective methods for the control of this pre-harvest fruit disease under field conditions.

Bacillus subtilis NBRI-W9 simultaneously activates SAR and ISR against Fusarium chlamydosporum NBRI-FOL7 to increase wilt resistance in tomato.

The study aimed to determine the pathogenicity of Fusarium species currently prevalent in tomato fields having history of chemical fungicide applications and determine the bio-efficacy of Bacillus subtilis NBRI-W9 as a potent biological control agent. Fusarium was isolated from surface-sterilized infected tomato plants collected from fields. Pathogenicity of 30 Fusarium isolates was determined by in vitro and in vivo assays. Following Koch's postulates, F. chlamydosporum (FOL7) was identified as a virulent pathogen. The biological control of FOL 7 by B. subtilis NBRI-W9 (W9) and the colonization potential of W9 were established using spontaneous rifampicin-resistant mutants. W9 showed 82% inhibition of FOL7 on a dual-culture plate and colonization levels in tomato plants of ∼5.5, ∼3.3, and ∼2.2 log10 CFU/g in root, stem, and leaf tissue, respectively. Antagonistic activity was shown by scanning electron microscopy (SEM) and cell-wall-degradative enzymes. W9 reduced FOL7 infection in net-house and field experiments by 60% and 41%, respectively. Biochemical investigation, defence enzymes, defence gene expression analysis, SEM, and field studies provide evidence of hyperparasitism and induced resistance as the mode of biological control. The study also demonstrates that the potent biocontrol agent W9, isolated from Piper, can colonize tomato plants, control fungal disease by inducing induced systemic resistance (ISR) and systemic acquired resistance (SAR) simultaneously, and increase crop yield by 21.58% under field conditions. This study concludes that F. chlamydosporum (NBRI-FOL7) is a potent, fungicide-resistant pathogen causing wilt in tomatoes. NBRI-W9 controlled FOL7 through mycoparasitism and simultaneously activated ISR and SAR in plants, providing an attractive tool for disease control that acts at multiple levels.

Assessment of the Microbial Quality of Food Sold in Some Restaurants within Katsina Metropolis

Foods are substances that when consumed provide the body with nutrients for growth and development. Foods for consumption should be within the acceptable limit of microbial load, exceeding it may lead to food-borne intoxication and illness. This study aimed to determine the microbial quality of commonly sold foods in some restaurants within Katsina metropolis. Physiochemical properties of the food namely; pH, temperature, colour, and taste were determined using a pH meter, thermometer, and organoleptic approach respectively. Conventional methods of identification were used to identify the isolates and a modified method by Kirby Bauer was employed to determine antimicrobial assays of the identified isolates. The results obtained showed that the physiochemical parameters of pH and temperature range between 5.50 to 7.40, and 30.0 oC to 32.0 oC respectively with a normal taste and colour. Total bacterial (1.04 x107 CFU/g) and fungal (4.8 x106 CFU/g) counts of the samples fall within the unsatisfactory limits set by the International Commission on Microbiological Specifications for Food (ICMSF). A total of nine (9) bacteria and five (5) fungi were identified from fifteen (15) samples examined. E. coli (26.31%) was most prevalent followed by Enterobacter aerogens and Staphylococcus epidermis (15.78%), Bacillus subtilis, and Salmonella spp (10.52%) while Proteus mirabilis, Micrococcus luteus, Pseudomonas aeroginosa, and Clostridium spp. have the least occurrence (5.26%). Aspergillus flavus (45.45%) was most prevalent among the fungal isolates followed by Mucor (27.27%) and Botrytis, Alternaria, and Fusarium chlamydosporum (9.09%) have the least occurrence. The antimicrobial assay shows that Gentamycin, levofloxacin, Erythromycin, and Ciprofloxacin were effective against Micrococcus luteus, Staphylococcus spp., Clostridium spp., and Bacillus subtilis. Norfloxacin and Amoxicillin were resisted by Micrococcus luteus and Staphylococcus spp., Ketoconazole and Fluconazole inhibited Mucor and Aspergillus flavus but were resisted by Alternaria, Botrytis, and Fusarium chlamydosporum. It was concluded that foods sold in some restaurants within the Katsina metropolis fall within the unsatisfactory limits of ICMSF standards, thus, improved strict hygiene compliance is recommended.

Some soilborne pathogens causing root rot and wilting of pistachio trees in southeastern Turkey

Soilborne fungal pathogens that cause root rot, wilting and dying are the most important problems in pistachio production. The purpose of this study was to examine, isolate, and diagnose the pathogens from diseased pistachio trees in orchards and nurseries located in southeastern Turkey. Fungi isolated from the pistachio trees were identified by morphology and the sequences of the internal transcribed spacer (ITS) region and translation elongation factor-1α (TEF-1α). Fusarium solani, Fusarium oxysporum, Fusarium brachygibbosum, Fusarium chlamydosporum and Macrophomina phaseolina were the most important fungi causing root rot, wilting and decline of pistachio trees. Pathogenicity studies showed that all of the fungi identified can colonize and damage the vascular tissues of a sapling and cause substantial lesions and vascular discolourations. This study provides the first evidence of wilting due to the root and crown rot in pistachio trees in Siirt province of Turkey caused by some Fusarium species, especially F. solani, F. oxysporum, F. chlamydosporum, F. brachygibbosum and M. phaseolina. Finally, the research enabled the identification of some fungal pathogens that are seriously harming pistachio trees in southeastern Turkey.

Identification of Some Fungi Causing Okra Root Rot Disease from Different Regions of Anbar and Waist and Testing Pathogenicity

The study was conducted in the Department of Plant Protection - College of Agriculture - University of Anbar for the year 2022, as the results of collecting samples from the regions of Anbar and Waist governorates showed the spread of okra root rot disease in most of the study areas, and the results of phenotypic and molecular diagnosis showed the presence of the fungal species Pythium Aphanidermatum, Fusarium proliferatum, Epicoccum nigrum, Itersonilia perplexans, Fusarium chlamydosporum, Rhizoctonia solani, which were deposited in the International Genbank OQ572440, OQ540926, OQ566939, OQ540927, OQ540928, OQ540929 (NCBI) seeds, respectively. Okra, as the tested isolates achieved a significant decrease in the germination of okra seeds on the culture medium (W.A. Water agar) compared with the control treatment that was not contaminated with any of the tested isolates, in which the infection rate was 0.0%.

Physico-Chemical Alternatives for Synthesis of Metal Nanoparticles Using Fusarium Chlamydosporum

Abstract Introduction/Objective Background: Synthesizing metal nanoparticles (NPs) by chemical or physical methods is difficult due to energy and time consumption, equipment costs, and chemical toxicity. Chemosynthesis-derived NPs are unstable, limiting their biological applications. Thus, identifying alternative green sources to address these drawbacks is difficult scientifically. The hardest part of green metal nanoparticle synthesis is finding a nontoxic natural product and an eco-friendly solvent. Objectives: Isolation of fungal endophytes from Eucalyptus sideroxylon leaves to synthesize ZnO and Au nanoparticles. Methods/Case Report Materials and methods: We used healthy Eucalyptus sideroxylon plant samples from the desert research center to separate endophytes. All fungi were grown on malt extract broth on a rotary shaker at 28 °C (120 rpm) for 96 hours after isolation. Biomass components were removed by filtration and washing in distilled water. Nanoparticles came from biomass cell filtrate. 0.1 M, 1 mL of Zn SO4, and HAuCl4 were added to 10 mL of fungal filtrate and agitated for 24 hours in the dark at room temperature to make Zn and Au nanoparticles separately. Characterization of nanoparticles shows a green synthesis of ZnONPs and AuNPs. Results (if a Case Study enter NA) Results: Fungal endophytes' filtrates were mixed with 1mM Zn SO4 and HAuCl4 solutions to test their extracellular biosynthesis of ZnO and Au NPs. The fungal filtrate became colorless and violet after mixing with Zn SO4 and HAuCl4. Only FI-03 is from 13 (FI-01 to FI-013). The most potent fungal strain for Zn O NP and Au NP nanoparticle synthesis was Fusarium Chlamydosporum. Pure, mostly spherical ZnO and Au NPs averaged 19.3 and 22.1 nm. UV-Vis absorption: Excitonic absorption peaks of ZnO NPs were between 300 and 400 nm. ZnO NPs' maximum absorption peak was 305 nm, while Au NPs' peak was 520 nm. One absorption peak indicates metallic gold nanoparticles. Au and ZnO NPs aggregate the most due to their hydrophilicity, HD of 34.88 and 15.77 nm, and PdI of 0.77, 1.00, and 0.952. Gold face-centered cubic fcc structure dominates Au NPs' XRD pattern. EDX shows 64.61 and 35.39 percent Zn and O, respectively, in both nanoparticles. The optical absorption band of gold nanocrystallites peaked at 2.2 keV in energy-dispersive X-rays. Conclusion Endophytic fungus biosynthesizes ZnO and Au NPs, which are bioactive compounds for medicine and food without toxic chemicals and are environmentally friendly.

Seasonal diversity & spaciotemporal distribution of fungal endophytes associated with the medicinal plant Coleus forskohlii Briq.

Fungi that colonize the healthy tissues of the plants without showing any disease symptoms in the host plants are termed as fungal endophytes. The presence of fungal endophytes provides a positive effect on the host’s growth & development and also triggers the production of some essential bioactive compounds in the host. This study was undertaken to isolate, identify and understand the spaciotemporal distribution and seasonal diversity of fungal endophytes associated with the leaf, stem & root of Coleus forskohlii, an important and endangered medicinal plant. Sampling was done for a period of 12 months between May 2020–April 2021. A total of 950 fungal endophytes were isolated from a total of 1680 tissues of the leaf, stem & root of C. forskohlii. The fungi were identified based on their morphological features and some of them were identified by molecular identification by 18S rRNA sequencing. The endophytic isolates belonged to 10 different orders belonging to 3 different classes-Sordariomycetes (Hypocreales, Xylariales, Microascales, Trichosphaeriales, Glomerellales & Sordariales), Dothiomycetes (Pleosporales, Capnodiales, Botryosphaeriales) & Eurotiomyctes (Eurotiales). About 81.26% of the isolates belonged to Ascomycota & 2.63% of the isolates belonged to Mucoromycota. Chaetomium globosum, Collariella bostrychodes, C. robusta, Colletotrichum gloeosporioides, Fusarium chlamydosporum, Sterile hyaline mycelia, Aspergillus niger, Xylaria curta, X. grammica, Mucor circinelloides & Trichoderma harizianum were the frequently isolated species of fungi. C. globosum, C. bostrychodes, C. gloeosporioides, sterile hyaline mycelia & X. curta were found distributed in all the tissues of the plant. C. forskohlii has thus revealed a rich diversity of fungal endophytes that could be isolated & cultured to yield some pharmacologically important bioactive compounds.

The determination of the biological function of bacterial pink pigment and Fusarium chlamydosporum on alfalfa (Medicago sativa L.)

Bacterial pigment is one of the secondary metabolites produced by bacteria and has functions that are yet to be understood in relation to soil-borne pathogenic fungi and plants in mutualistic processes. The study evaluates the growth, photosynthetic, and physiological characteristics of alfalfa after interacting with different concentrations of Cp2 pink pigment and Fusarium chlamydosporum. The findings showed that Cp2 pink pigment has the ability to inhibit the growth of alfalfa, with the inhibition ratio gradually increasing with rising concentration. F. chlamydosporum inhibited the growth of alfalfa, which reduced the photosynthetic physiological response and elevated antioxidant enzymes, which are typically manifested by yellowing leaves and shortened roots. Under the combined effect of Cp2 pink pigment and F. chlamydosporum, increasing concentrations of Cp2 pink pigment intensified the symptoms in alfalfa and led to more pronounced growth and physiological response. This indicates that the Cp2 pink pigment is one of the potential virulence factors secreted by the Erwinia persicina strain Cp2, which plays an inhibitory role in the interactions between F. chlamydosporum and alfalfa, and also has the potential to be developed into a plant immunomodulator agent.

Production of Lycopene by Fusarium chlamydosporum and its Anti-inflammatory Activity on Raw Macrophage Cell Line

Production of Lycopene by Fusarium chlamydosporum and its Anti-inflammatory Activity on Raw Macrophage Cell Line

Petroleum-Degrading Fungal Isolates for the Treatment of Soil Microcosms.

The main purpose of this study was to degrade total petroleum hydrocarbons (TPHs) from contaminated soil in batch microcosm reactors. Native soil fungi isolated from the same petroleum-polluted soil and ligninolytic fungal strains were screened and applied in the treatment of soil-contaminated microcosms in aerobic conditions. The bioaugmentation processes were carried out using selected hydrocarbonoclastic fungal strains in mono or co-cultures. Results demonstrated the petroleum-degrading potential of six fungal isolates, namely KBR1 and KBR8 (indigenous) and KBR1-1, KB4, KB2 and LB3 (exogenous). Based on the molecular and phylogenetic analysis, KBR1 and KB8 were identified as Aspergillus niger [MW699896] and tubingensis [MW699895], while KBR1-1, KB4, KB2 and LB3 were affiliated with the genera Syncephalastrum sp. [MZ817958], Paecilomyces formosus [MW699897], Fusarium chlamydosporum [MZ817957] and Coniochaeta sp. [MW699893], respectively. The highest rate of TPH degradation was recorded in soil microcosm treatments (SMT) after 60 days by inoculation with Paecilomyces formosus 97 ± 2.54%, followed by bioaugmentation with the native strain Aspergillus niger (92 ± 1.83%) and then by the fungal consortium (84 ± 2.21%). The statistical analysis of the results showed significant differences.

Investigating the impact of fungicides and mungbean genotypes on the management of pod rot disease caused by Fusarium equiseti and Fusarium chlamydosporum.

Mungbean is a vital pulse crop in India that can thrive in dry-land conditions and is grown in three seasons, with the added benefit of being used as green manure due to its ability to fix atmospheric nitrogen. Recently, pod rot disease has emerged as a serious threat to mungbean cultivation in India. In this study, morpho-molecular identification of associated pathogens and the bio-efficacy of systemic and non-systemic fungicides as well as genotype screening was performed during the years 2019 and 2020. The pathogens associated with this disease were confirmed on the basis of morphological and molecular characterization. For the molecular characterization, the translation elongation factor 1-alpha (tef-1) gene sequences were amplified by using primers (EF1 and EF2). Under in vitro conditions, trifloxystrobin + tebuconazole 75% WG was found to be the most effective against Fusarium equiseti (ED50 2.39 μg ml-1) and Fusarium chlamydosporum (ED50 4.23 μg ml-1) causal agents of pod rot of mungbean. Under field conditions, three applications of trifloxystrobin + tebuconazole 75% WG at 0.07% as a foliar application at fortnightly intervals starting from the last week of July proved to be the most effective against pod rot disease on mungbean cultivars, i.e., ML 2056 and SML 668. To identify the potential resistance sources, 75 interspecific derivative and mutant lines of mungbean were screened for disease reaction to pod rot under natural epiphytotic conditions for the years 2019 and 2020. Genotypic differences were observed for resistance to pod rot disease. The study revealed that among the tested genotypes, ML 2524 exhibited resistance to pod rot disease, with a disease incidence of 15.62% and disease severity of 7.69%. In addition, 41 other genotypes were found to be moderately resistant (MR) to the disease. Altogether, the identified management options will offer an immediate solution to manage this disease under recent outbreak conditions and pave a path for futuristic disease management using identified resistant sources in breeding programs.

Pod rot of mungbean in Punjab, India: First record of association of Fusarium equiseti and Fusarium chlamydosporum

Pod rot of mungbean in Punjab, India: First record of association of Fusarium equiseti and Fusarium chlamydosporum

Fungal and Bacterial Contaminants Associated with the Spoilage of Mushroom Spawn

Contamination has been a major problem associated with spawn of mushroom. In this study, the contaminating microorganisms in the spawn were isolated, identified and described. Results indicated that majority of microorganisms causing spawn contamination were mainly fungal pathogens; a very low percentage of bacterial contamination was observed. The fungal species causing contamination were Fusarium chlamydosporum, Phoma exigua, Aspergillus niger, Penicillium chrysogenum, Aspergillus fumigatus and Fusarium pallidoroseum. Only one bacterial contaminant i.e. Bacillus sp. was reported under study. Aspergillus fumigatus was the major fungal contaminant and Bacillus sp. was the only bacterial contaminant isolated from spawn incubation room environment, whereas from spawn inoculation room contaminants isolated wereFusarium pallidoroseum and Staphylococcus sp.

Comparative proteome profiling of fusarium chlamydosporum and elucidation of pigment biosynthetic pathway under nitrogen stress

The main aim of this study was to understand the protein expression of F. chlamydosporum in two different medium composition in varying concentrations of nitrogen. The interesting phenomenon of producing diverse pigments by a single strain in different concentrations of Nitrogen made us further to explore the difference in the protein expression of the fungus when grown in these two media. For this, we had adopted non-gel-based method of protein separation by LC-MS/MS analysis followed by label free identification of proteins by SWATH analysis. The molecular and biological functions of each protein and their Gene Ontology annotations were analyzed by UniProt KB and KEGG pathway; the secondary metabolite pathways and the carbohydrate metabolic pathways were analyzed by DAVID bioinformatics tool. The positively regulated proteins biologically functioned for the secondary metabolite production in optimized medium were Diphosphomevalonate decarboxylase (terpenoid backbone biosynthesis), Phytoene synthase (carotenoid biosynthesis), 6,7-dimethyl-8-ribityllumazine synthase (riboflavin biosynthesis). The main characteristic change observed was that proteins related to carotenoid biosynthesis and terpenoid synthesis were not regulated in nitrogen limited medium. Except for the protein 6,7-dimethyl-8-ribityllumazine synthase, all the enzymes related to fatty acid biosynthesis and polyketide chain elongation were up regulated. Apart from the proteins related to secondary metabolite production, two novel proteins were found to be up regulated in Nitrogen Limited Medium; C-fem protein responsible for fungal pathogenesis and DAO domain containing protein which functions as a neuromodulator and catalyzes the synthesis of dopamine. SignificanceThis particular strain of F. chlamydosporum of immense genetic and biochemical diversity represents an interesting example of a microorganism which can produce a variety of bioactive compounds and this can be exploited in various industries. The production of carotenoids and polyketides by this fungus when grown in the same media with different concentrations of Nitrogen has been published by us following which we analyzed the proteome sequence of the fungus in varying Nutrient conditions. Following the proteome analysis and expression, we could derive the pathway leading to the biosynthesis of varying secondary metabolites by the fungus which has not been published or studied so far.

Cultural Characterization and Antagonistic Activity of Cladobotryum virescens against Some Phytopathogenic Fungi and Oomycetes

In this study, the characteristic growth of Cladobotryum virescens on nine culture media was analyzed. The growing behavior of this fungus was dependent on the culture medium. In vitro analysis showed that oat agar was better than other media tested with the highest conidia production. The antifungal activity against Fusarium chlamydosporum and Alternaria brassicicola was evaluated by the Dual Culture method. C. virescens displayed high activity against both pathogens acting through antibiosis and mycoparasitism. This effect was increased by a higher competitiveness of the strain for the substrate. Furthermore, the crude ethyl acetate extract of the culture broth was tested in vitro against Botrytis cinerea and Septoria tritici, as well as the hemibiotrophic oomycete Phytophthora infestans using a microtiter plate assay at different concentrations. The extract showed excellent inhibition even below 5 ppm. According to these results, we concluded that C. virescens can be considered as a potential biological control agent in agriculture. To the best of our knowledge, this is the first study to investigate C. virescens as a biocontrol agent for different diseases caused by five relevant pathogens that affect cereals and vegetables.

Production of Two Novel Polyketide Pigments by Fusarium chlamydosporum

Aim: The aim of the present study was to evaluate the pigment production by the fungus Fusarium chlamydosporum in Glucose Peptone Yeast Extract medium and further to assess its toxicity by in vitro methods. Materials and Methods: The coloured crude extract yielded 4 fractions when subjected to column chromatography, upon which Fraction 2 and 4 were subjected to characterization procedures by UV-Visible spectrophotometry, Fourier Transform Infrared Spectroscopy and Molecular weight determination by Liquid Chromatography Mass Spectroscopy (LCMS). The toxicity of the pigments was evaluated in vitro on L-929 Mouse Fibroblast cell lines by MTT Assay. Results: The fungus produced dark red pigment in Glucose Peptone Yeast Extract medium on extraction with ice cold chloroform. The results summarized Fraction 2 and 4 to be the polyketide derivatives, Rubrofusarin and 8-O-methyl fusarubin respectively wherein the IC50 values of rubrofusarin and 8-O-methyl fusarubin was 183.85 and 82.366 μg/ml respectively. Conclusion: The significance of the present study lies in the characterization of 2 novel polyketides, rubrofusarin and 8-O-methyl fusarubin from F. chlamydosporum and there have been no literature reviews on the production of these pigments from the fungus.

Isolation and identification of Epicoccum nigrum as the causal agent of brown spot disease in Solanum tuberosum in China

AbstractBrown spots occurring on potato leaves affect the normal growth of host plants. Recently, a new brown spot disease with some black dots was discovered on potato leaves in Dingxi, China. To confirm the causal agents of potato brown spots, the diseased lesions were collected and disinfected, and only one type of isolate, with football‐shaped conidia, was obtained from disinfected diseased leaves in three experimental fields. Pathogenicity tests of four representative isolates revealed that they can cause disease symptoms on 50%–75% of wounded and non‐wounded potato leaves. In addition, a typical isolate, DXPH, was identified based on morphological and molecular characteristics, and the colony and conidial characteristics were similar to those of Epicoccum sp. Multilocus sequence analysis showed that the internal transcribed spacer (ITS), RNA polymerase II second largest subunit (RPB2) and β‐tubulin (Tub2) genes of DXPH were 100%, 100% and 99% identical to the sequences of Epicoccum nigrum (CBS 140523), respectively. Additionally, antagonistic evaluation confirmed that the representative pathogenic strain DXPH showed greatest inhibition of the mycelial growth of Colletotrichum coccodes and Fusarium chlamydosporum in vitro, with antagonistic effects of 66.67% and 61.56%, respectively. Our findings provide evidence that E. nigrum can be pathogenic to potatoes in vivo in China, while retaining a biocontrol capacity on C. coccodes, Fusarium spp. and Botrytis cinerea in vitro, which will be helpful for the effective control of potato brown spot disease and management of the use of E. nigrum as a biological control agent.

Synthesis, Spectral Studies and Antimicrobial Activity of Zinc(II) Azide Complexes with N,N-Donor and N,N,S-Donor Schiff Base Ligands Derived from 2-Pyridinecarboxaldehyde

Two water soluble Zn(II) Schiff base complexes of composition [Zn(L1)3][Zn(N3)4] (1) and [Zn(L2)2][Zn(N3)4] (2) were synthesized using bidentate N,N-donor (L1) and tridentate N,N,S-donor (L2) of Schiff base ligands viz. (E)-1-phenyl-N-(pyridin-2-ylmethylene)methanamine (L1) and (E)-2-((pyridin-2-ylmethylene)amino)benzenethiol (L2). Different spectroscopic tools such as FT-IR, UV-Vis, 1H NMR and fluorescence spectroscopy have been employed to characterize complexes 1 and 2. Efforts for getting single crystals suitable for X-ray crystal structure could not be achieved. However, from the spectroscopic data and on the basis of the structures of the related zinc(II) complexes reported earlier in the literature, the complexes could be proposed to adopt six coordinated octahedral geometries in one zinc centre coordinated to the ligands and while the other zinc centre has four azides (N3) terminally coordinated resulting in the octahedral and tetrahedral metal geometries around zinc metal atoms. The compounds behave as electrolytes in acetonitrile solution. In vitro antimicrobial activity of the Zn(II) complexes were studied against some microbes like Aspergillus niger, Fusarium ventricossum and Fusarium chlamydosporum. Effective antifungal activity of complex 2 was found against the tested fungal strains.