Fungal Isolates Research Articles

Ethyl Acetate Extracts Endophytic Fungi from the Medicinal Tree Fern Cyathea Contaminans (Hook) Copel with Antimicrobial Activity

Medicinal plants are a rich source of naturally occurring substances utilized in treating a wide range of diseases; as a result, they serve as the basis for discovering new drugs. Research has focused on the relationship between endophytic microorganisms and host plants, as they produce a variety of secondary metabolites with significant biological functions. This study aimed to extract the endophytic fungi from various plant parts, including the roots, barks, and leaves of the Cyathea contaminans (Hook) Copel, which was collected from Kerinci, Jambi, Indonesia. By employing direct planting and pouring techniques with fungal culture media, the fungi were separated from the roots, stems, hairs, and leaves of C. contaminans and grown on rice media. The secondary metabolite of the fungus was extracted using ethyl acetate. The extracts were then tested for antimicrobial activity using a disk diffusion assay against microbial pathogens Staphylococcus aureus ATCC29213, Escherichia coli ATCC25922, and Methicillin-Resistant Staphylococcus aureus (MRSA). This research yielded 19 endophyte fungi. In the antibacterial activity screening results, four fungal strains (CBK3, CDK1, CDK4, and CAK2) were active against S. aureus, MRSA, and E. coli, with an inhibition zone in the range of 15.08 ± 0.854 to 23.52 ± 0.87 mm. All active fungal isolates were identified molecularly. CBK3 and CDK1 were Paecilomyces subglobosus PP510226 and Penicillium citrinum PP510227, respectively, while CDK4 and CAK2 were comparable to Aspergillus terreus PP510229 and Aspergillus terreus PP510228. The four endophytic fungi of Cyathea contaminans may be a new source of antibacterial compounds. HIGHLIGHTS This is the 1st report of endophytic fungi isolated from medicinal tree fern Cyathea contaminans origin from Sungai Bungkal, Jambi, Indonesia. The four potential endophytic fungi that were successful in purification namely, Paecilomyces subglobosus, Penicillium citrinum, and Aspergillus tereus, which were reported as the source of bioactive compounds Endophytic fungi isolated from medicinal tree fern Cyathea contaminans showed good activity on some pathogenic bacteria: Staphylococcus aureus, Escherichia coli, and Methicillin-Resistant Staphylococcus aureus (MRSA) GRAPHICAL ABSTRACT

Characterization and applications of iron oxide nanoparticles synthesized from Phyllanthus emblica fruit extract

Nanotechnology is a treasure trove of diversified themes which are endowed with broad applications. Herein, iron oxide (Fe2O3) nanoparticles were synthesized using Phyllanthus emblica aqueous fruit extract. The UV-Visible spectrum exhibited a surface plasmon resonance peak at 295nm. Fourier Transform Infrared Spectroscopy provided insight into the functional groups responsible for capping. X-ray diffraction analysis authenticated the crystalline nature of nanoparticles, while energy dispersive X-ray spectroscopy divulged that iron and oxygen comprised 54% of the nanoparticles’ weight. Scanning electron microscopy established irregular morphology and agglomeration of nanoparticles. The Fe2O3 nanoparticles validated potent antimicrobial activity against 11 bacterial and 1 fungal isolates. The biggest zone of inhibition (23mm) was measured against S. enterica, whereas the smallest zone of inhibition (12mm) was documented against C. albicans and E. coli. The values for minimum inhibitory concentration ranged between 10 and 15μg/ml for all microbes. Nevertheless, no synergy was exhibited by the nanoparticles with any of the selected antibiotics (Fractional Inhibitory Concentration Index > 1). The photocatalytic dye degradation capability of Fe2O3 nanoparticles was assessed and the observations implied a significant increase in degradation of methyl red although, not of methylene blue. Furthermore, the nanoparticles were in possession of substantial antioxidant (34–38%) and anti-inflammatory (31–38%) capacities. Consequent upon the robust activities of P. emblica-mediated nanoparticles, these can be scrutinized for biomedical and environmental implementations in future.

“Isolation And Molecular Characterization Of Polythene-Degrading Fungus From Dumping Sites In Bhopal District, Madhya Pradesh”

“Isolation And Molecular Characterization Of Polythene-Degrading Fungus From Dumping Sites In Bhopal District, Madhya Pradesh”

Potential Bioactivities, Chemical Composition, and Conformation Studies of Exopolysaccharide-Derived Aspergillus sp. Strain GAD7.

This research identified a marine fungal isolate, Aspergillus sp. strain GAD7, which produces an acidic and sulfated extracellular polysaccharide (EPS) with notable anticoagulant and antioxidant properties. Six fungal strains from the Egyptian Mediterranean Sea were screened for EPS production, with Aspergillus sp. strain GAD7 (EPS-AG7) being the most potent, yielding ~5.19 ± 0.017 g/L. EPS-AG7 was characterized using UV-Vis and FTIR analyses, revealing high carbohydrate (87.5%) and sulfate (24%) contents. HPLC and GC-MS analyses determined that EPS-AG7 is a heterogeneous acidic polysaccharide with an average molecular weight (Mw¯) of ~7.34 × 103 Da, composed of mannose, glucose, arabinose, galacturonic acid, galactose, and lyxose in a molar ratio of 6.6:3.9:1.8:1.3:1.1:1.0, linked through α- and β-glycosidic linkages as confirmed by NMR analysis. EPS-AG7 adopted a triple helix-like conformation, as evidenced by UV-Vis (Congo Red experiment) and circular dichroism (CD) studies. This helical arrangement demonstrated stability under various experimental conditions, including concentration, ionic strength, temperature, and lipid interactions. EPS-AG7 exhibited significant anticoagulant activity, doubling blood coagulation time at a concentration of 3.0 mg/mL, and showed significant antioxidant activity, with scavenging activities reaching up to 85.90% and 58.64% in DPPH and ABTS+ assays at 5.0 mg/mL, and EC50 values of 1.40 mg/mL and 3.80 mg/mL, respectively. These findings highlight the potential of EPS-AG7 for therapeutic applications due to its potent biological activities.

Solubilization and enhanced degradation of benzene phenolic derivatives-Bisphenol A/Triclosan using a biosurfactant producing white rot fungus Hypocrea lixii S5 with plant growth promoting traits.

Endocrine disrupting chemicals (EDCs) as benzene phenolic derivatives being hydrophobic partition to organic matter in sludge/soil sediments and show slow degradation rate owing to poor bioavailability to microbes. In the present study, the potential of a versatile white rot fungal isolate S5 identified as Hypocrea lixii was monitored to degrade bisphenol A (BPA)/triclosan (TCS) under shake flask conditions with concomitant production of lipopeptide biosurfactant (BS) and plant growth promotion. Sufficient growth of WRF for 5 days before supplementation of 50 ppm EDC (BPA/TCS) in set B showed an increase in degradation rates by 23% and 29% with corresponding increase in secretion of lignin-modifying enzymes compared to set A wherein almost 84% and 97% inhibition in fungal growth was observed when BPA/TCS were added at time of fungal inoculation. Further in set B, EDC concentration stimulated expression of laccase and lignin peroxidase (Lip) with 24.44 U/L of laccase and 281.69 U/L of Lip in 100 ppm BPA and 344 U/L Lip in 50 ppm TCS supplemented medium compared to their respective controls (without EDC). Biodegradation was also found to be correlated with lowering of surface tension from 57.02 mN/m (uninoculated control) to 44.16 mN/m in case of BPA and 38.49 mN/m in TCS, indicative of biosurfactant (BS) production. FTIR, GC-MS, and LC-ESI/MSMS confirmed the presence of surfactin lipopeptide isoforms. The WRF also displayed positive plant growth promoting traits as production of ammonia, indole acetic acid, siderophores, Zn solubilization, and 1-1-aminocyclopropane-1-carboxylate (ACC) deaminase activity, reflecting its soil restoration ability. The combined traits of biosurfactant production, EDC degradation and plant growth promotion displayed by WRF will help in emulsifying the hydrophobic pollutants favoring their fast degradation along with restoration of contaminated soil in natural conditions.

Germplasm Resource Mining of Fen-Flavor Baijiu Brewing Micro-Organisms and Screening of Important Functional Strains

The exploration of microbial genetic resources for the production of fFen-flavor Baijiu has not only enriched the microbial library for baijiu production but has also laid the foundation for process improvement and strain optimization in baijiu brewing. In this study, a total of 177 fungal isolates were screened, including Saccharomyces cerevisiae, non-Saccharomyces cerevisiae, molds, and some pathogenic bacteria. Among them, Saccharomyces cerevisiae was the most abundant with 119 isolates, playing a major role in the fermentation of baijiu production. A total of 148 bacterial isolates were obtained from the fermentation mash samples, showing greater diversity compared to fungi. Bacillus species were the most abundant, with 94 isolates. Bacillus licheniformis, in particular, can produce a rich enzymatic system and flavor precursors, making it an important contributor to the sensory quality of baijiu. Lactic acid bacteria were the second most abundant, with 16 isolates. Additionally, five pathogenic fungal species were identified, including Candida pelliculosa, Candida lusitaniae, Fusarium oxysporum, Fusarium solani and Talaromyces marneffei. Six pathogenic bacterial species were also isolated, namely Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus xylosus, Moraxella osloensis, Actinomyces meyeri and Stenotrophomonas maltophilia. Finally, two strains of high acetate ethyl ester-producing yeast and lactate-degrading bacteria with good tolerance to temperature, pH, and ethanol concentration were identified as Saccharomyces cerevisiae and Bacillus licheniformis, respectively.

Dual-strategy approach for Rhynchophorus ferrugineus control: Endophytic Beauveria bassiana and Bacillus thuringiensis topical application

In an innovative approach to biological pest management, the entomopathogenic efficacy of endophytically colonized Beauveria bassiana and topically applied Bacillus thuringiensis was evaluated against various larval instars (2nd, 4th, and 6th) of the red palm weevil (RPW), Rhynchophorus ferrugineus. Initially, date palm leaf petioles were inoculated with five distinct isolates of the fungus to ascertain their endophytic potential over two years. Subsequently, the most proficiently colonized fungal isolate was selected for subsequent experimentation. During individual entomopathogen applications, larval instars of RPW were presented with plant petioles and colonized with fungus at 30 days post-inoculation or immersed in bacterial inoculum. Ιn combined treatments, larvae were exposed to both entomopathogen-treated plant petioles concurrently. The tested bacterium was administered at three concentrations (30, 40, and 50 μg/ml). Larval mortalities were markedly lower in treatments involving individual entomopathogens, whereas integrated applications yielded higher mortalities. Treatments associated with heightened larval mortalities corresponded to diminished pupation, adult emergence, and egg eclosion rates. Furthermore, the simultaneous application of both entomopathogens bolstered larval mortalities of RPW both additively and synergistically, with concentration also playing an important role. Similarly, the developmental periods of various insect stages were substantially influenced by combined entomopathogen applications. The inherent prevalence of these pathogens and their ability to colonize crop plants internally for extended periods render them promising agents against cryptic-feeding insects like RPW. However, further evaluation of suitable entomopathogen strains and optimal doses under field conditions is imperative before formulating concrete recommendations for date palm growers.

New insights into RNA mycoviruses of fungal pathogens causing Fusarium head blight

Fusarium head blight (FHB) continues to be a major problem in wheat production and is considered a disease complex caused by several fungal pathogens including Fusarium culmorum, F. graminearum and F. equiseti. With the objective of investigating diversity of mycoviruses in FHB-associated pathogens, we isolated Fusarium spp. from six wheat (Triticum aestivum) cultivars. In total, 56 Fusarium isolates (29 F. culmorum, 24 F. graminearum, one F. equiseti) were screened for mycoviruses by extracting and sequencing double-stranded RNA. We found that a large proportion of Fusarium isolates (46 %) were infected with mycoviruses. F. culmorum, previously described to harbor only one mycovirus, tended to host more viruses than F. graminearum, with a few isolates harboring seven mycoviruses simultaneously. Based on the RNA-dependent RNA polymerase domain analysis, ten were positive-sense single-stranded RNA viruses (related to viruses from families Mitoviridae, Botourmiaviridae, Narnaviridae, Tymoviridae, Gammaflexiviridae, as well as proposed Ambiguiviridae and ormycovirus viral group), one was double-stranded RNA virus (Partitiviridae), and five were negative-sense single-stranded RNA viruses (related to members in the families of Yueviridae, Phenuiviridae, Mymonaviridae, as well as proposed Mycoaspiviridae). Five mycoviruses were shared between F. graminearum and F. culmorum. These results increase our general understanding of mycovirology. To our knowledge, this is the first in-depth report of the mycovirome in F. culmorum and the first report on the diversity of mycoviruses from Danish isolates of FHB-causing fungi in general.

Isolation and Characterization of Pathogen causing Northern Corn Leaf Blight of Maize in Ri-Bhoi, Meghalaya, India

The present study was carried out to identify and characterize the Exserohilum turcicum causing northern corn leaf blight of maize based on the cultural, morphological and molecular characteristics. Diseased leaf samples from maize fields exhibiting typical cigar shaped symptoms of northern corn leaf blight were collected from the research fields of CPGS-AS (Umiam), College of Agriculture (Kyrdemkulai) and ICAR-RC for NEH region (Umiam) located in Ri-Bhoi district, Meghalaya. Through cultural, morphological, molecular characterization the fungal isolate was identified as Exserohilum sp. Phylogenetic analysis of ITS rDNA gene sequence indicates as Exserohilum turcicum is associated with the disease northern corn leaf blight of maize. The findings underscore the importance of pathogen Exserohilum turcicum causing northern corn leaf blight impact on the maize crop, highlighting potential threat to its production.

The effects of organic waste on the postharvest fungal attack and disease severity on <i>Irvingia gabonensis</i> kernels

The effects of organic waste, orange peels and charcoal on the postharvest fungal attack and disease severity on Irvingia gabonensis kernels stored for six (6) months was investigated. Irvingia gabonensis kernels were treated with orange peels and charcoal and the fungal load and diversity were determined using standard microbiological techniques. The study revealed that the same fungal species which include Aspergillus fumigatus, Aspergillusniger, Aspergillus terreus and Mucorspp were encountered in both treatment and control. Furthermore, it was observed that disease severity in the treatment sample reduced by 50 % on the average. The kernels stored in bags without treatment was discoloured and lost its market value whereas 86-88% of kernels stored in bags with either dried orange peels or charcoal remained in good condition. It was observed that the fungal load which ranged 1 CFU/g - too many to count in the control was significantly higher than those stored in bottles with treatment (1-3CFU/g). In orange peel treated kernels Aspergillus fumigatus was the most occurring fungal isolate (3 CFU/g). Aspergillus fumigatus and Mucor spp. were the most occurring in charcoal treated kernels with 2 CFU/g. while Mucor spp. was the most occurring (25 CFU/g) in the control, closely followed by Aspergillus fumigatus (14 CFU/g). Orange peels and charcoal were effective in reducing fungal spoilage of kernels and would prove useful in reducing postharvest loss.

Fungi from Antarctic marine sediment: characterization and assessment for textile dye decolorization and detoxification.

Cold-adapted microorganisms can produce enzymes with activity at low and mild temperatures, which can be applied to environmental biotechnology. This study aimed to characterize 20 Antarctic fungi to identify their genus (ITS rDNA marker) and growth temperatures and evaluate their ability to decolorize and detoxify the textile dye indigo carmine (IC). An individual screening was performed to assess the decolorization and detoxification of IC by the isolates, as well as in consortia with other fungi. The isolates were affiliated with seven ascomycete genera: Aspergillus (n = 4), Cosmospora (n = 2), Leuconeurospora (n = 2), Penicillium (n = 3), Pseudogymnoascus (n = 6), Thelebolus (n = 2), and Trichoderma (n = 1). The two isolates from the genus Leuconeurospora were characterized as psychrophilic, while the others were psychrotolerant. The Penicillium isolates were able to decolorize between 60 and 82% of IC. The isolates identified as Pseudogymnoascus showed the best detoxification capacity, with results varying from 49 to 74%. The consortium using only Antarctic ascomycetes (C1) showed 45% of decolorization, while the consortia with the addition of basidiomycetes (C1 + Peniophora and C1 + Pholiota) showed 40% and 50%, respectively. The consortia C1 with the addition of the basidiomycetes presented a lower toxicity after the treatments. In addition, a higher fungal biomass was produced in the presence of dye when compared with the experiment without the dye, which can be indicative of dye metabolization. The results highlight the potential of marine-derived Antarctic fungi in the process of textile dye degradation. The findings encourage further studies to elucidate the degradation and detoxification pathways of the dye IC by these fungal isolates.

Isolation, morphological characterization, and screening virulence of Beauveria bassiana and Metarhizium robertsii fungal isolates on Galleria mellonella

Background Entomopathogenic fungi exists naturally in plants as an asymptote and have the potential to reduce the population of insect pests through indirect interactions. This study was conducted to detect and characterize the endophytic fungi Beauveria bassiana and Metarhizium robertsii from the rhizosphere soil of tomato plants and their virulence effect on Galleria melonella. Methods From the rhizosphere soil of 40 tomato fields, three Beauveria bassiana and seven Metarhizium robertsii isolates were isolated using the galleria bait method. All fungi isolate were morphologically characterized by their colony color, shape, and surface texture. Isolates with the highest percentages of germination, conidial yield, and radial growth were selected, and their virulence was evaluated on second instar larvae of Galleria melonella under laboratory conditions. Results In this study, Beauveria bassiana showed white colony color and aseptate hyphae, whereas Metarhizium robertsii showed dark green to light green colony color and septate hyphal structures. Maximum spore production and conidial length were obtained by Beauveria bassiana isolate APPRC-27 with 2.67x107 spores ml-1 and 3.24 µm, respectively. Colony radial growth rates ranged from 1.73 to 3.24 mm day-1. The results revealed that the highest mortality rate of Galleria melonella (100%) was obtained by Metarhizium robertsii isolates K-61 and K-102 at a concentration of 1x108 conidial ml-1 at 7 days post-inoculation. The lowest mortality rate was registered by Metarhizium robertsii isolate RST-11. Conclusions In the present study, isolates that produced the most spores and had the highest germination rates were the most virulent to Galleria mellonella second instar larvae. Therefore, virulent entomopathogenic fungi, Beauveria bassiana and Metarhizium robertsii, are promising bioagents for the control of insect pests.

Phoma herbarum: A Potential Biocontrol Agent Against Weeds, that Promotes Wheat Growth

The usage of chemical weedicide adversely affects the soil fertility and environment. Hence, in order to reduce the use of chemical weedicide, current study was aimed to isolate plant pathogenic microorganisms from diseased weeds and evaluate their potential as a bioherbicide in wheat field. Twelve bacterial and thirty-one fungal isolates were screened to determine their bioherbicidal activity against prevalent weeds (Avena fatua, Phalaris minor, and Chenopodium album) by using detached leaf assay and in-vitro seed testing methods. Among the forty-three isolates, two potential isolates were selected for further studies. Potential fungal isolates DGL 8C and DGL 7A with significant bioherbicidal activity were molecularly (ITS sequencing) identified as Phoma herbarum R21 (GenBank ID- ON705696) and K_NESO2 (GenBank ID- ON705704). Phoma herbarum R21 was chosen for further research due to its superior herbicidal effect and positive influence on wheat growth. Effective herbicidal activity (up to 90%) of potential isolate was obtained in pre-germination testing, compared to control. Cell free culture filtrate (CFCF) treatment showed nonspecific inhibition in the germination of weeds and wheat. While, CFCF selectively deteriorated the target weeds in post-germination treatment. Phoma herbarum R21 enhanced the growth of Durum wheat varieties Poshan and Tejas, as it promoted the growth of shoot, root, and fresh weight up to 88% compared to control. Phoma herbarum R21 significantly inhibited the growth of phytopathogenic fungi up to 57%. In this study, Phoma herbarum R21 was identified as a potential bioherbicide against the weeds of wheat along with its growth promoting and antifungal activities.

Molecular Dialogue During Host Manipulation by the Vascular Wilt Fungus Fusarium oxysporum.

Vascular wilt fungi are a group of hemibiotrophic phytopathogens that infect diverse crop plants. These pathogens have adapted to thrive in the nutrient-deprived niche of the plant xylem. Identification and functional characterization of effectors and their role in the establishment of compatibility across multiple hosts, suppression of plant defense, host reprogramming, and interaction with surrounding microbes have been studied mainly in model vascular wilt pathogens Fusarium oxysporum and Verticillium dahliae. Comparative analysis of genomes from fungal isolates has accelerated our understanding of genome compartmentalization and its role in effector evolution. Also, advances in recent years have shed light on the cross talk of root-infecting fungi across multiple scales from the cellular to the ecosystem level, covering their interaction with the plant microbiome as well as their interkingdom signaling. This review elaborates on our current understanding of the cross talk between vascular wilt fungi and the host plant, which eventually leads to a specialized lifestyle in the xylem. We particularly focus on recent findings in F. oxysporum, including multihost associations, and how they have contributed to understanding the biology of fungal adaptation to the xylem. In addition, we discuss emerging research areas and highlight open questions and future challenges.

Endophytic fungal diversity and bioactive potentials: investigating antimicrobial and antioxidant activities.

This study investigates the colonization of endophytic fungi in nettle leaf tissues and evaluates their antibacterial and antioxidant activities. Using an inverted optical microscope, extensive fungal colonization was observed in all leaf parts, with hyphae prevalent in epidermal cells, parenchyma cells, and vascular tissues. 144 endophytic fungal isolates were isolated from 800 leaf fragments, indicating an 18% retention rate. ANOVA analysis revealed significant differences (p < 0. 001) in colonization frequencies among 20 subjects, with subject 3 showing the highest frequency (40%) and subject 11 the lowest (2. 5%). Ethyl acetate extracts of the three most abundant endophytic fungi demonstrated notable antibacterial activity against both Gram-positive and Gram-negative bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). Inhibition zones ranged from 9. 5 to 15. 16 mm, with minimum inhibitory concentrations (MICs) between 0. 19 to 25 mg/mL. Alternaria sp. exhibited the highest antimicrobial activity against MRSA. Antioxidant activity was assessed using the DPPH radical scavenging test and FRAP method. All extracts showed substantial free radical scavenging properties, with IC50 values close to those of standards like BHT. Alternaria sp. had the highest antioxidant activity, followed by Epicocum sp. and Ulocladium sp. The FRAP method confirmed high reducing potential, with Alternaria sp. again exhibiting the highest activity. These findings highlight the potential of endophytic fungi in nettle leaves as sources of antimicrobial and antioxidant agents, with significant implications for pharmaceutical and biotechnological applications.

Synthesis and Characterization of Silver Nanoparticles Stabilized with Biosurfactant and Application as an Antimicrobial Agent.

Surfactants can be used as nanoparticle stabilizing agents. However, since synthetic surfactants are not economically viable and environmentally friendly, biosurfactants are emerging as a green alternative for the synthesis and stabilization of nanoparticles. Nanoparticles have been applied in several areas of industry, such as the production of biomedical and therapeutic components, packaging coating, solar energy generation and transmission and distribution of electrical energy, among others. The aim of this study was to synthesize, in a simple and green way, silver nanoparticles (AgNPs) using the biosurfactant produced by Candida lipolytica UCP 0899 as a stabilizer. AgNPs were examined and morphologically characterized using the techniques of ultraviolet-visible spectroscopy (UV-visible), scanning electron microscopy (SEM), zeta potential and energy dispersive X-ray spectroscopy (EDS). Newly formed silver nanoparticles showed a maximum UV-visible absorption peak at 400 nm, while a shift to 410 nm was observed in those stored for 120 days. SEM micrograph confirmed the formation of nanoparticles with an average size of 20 nm and with a predominant spherical structure, while a zeta potential of -60 mV suggested that the use of the biosurfactant promoted their stability. Stabilized nanoparticles were tested for their antimicrobial activity against bacterial isolates of Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli and Enterobacter sp., as well as fungal isolates of Candida albicans and Aspergillus niger. At a concentration of 16.50 µg/mL, AgNPs inhibited the growth of all target microorganisms according to the following decreasing order: E. coli (95%), S. aureus, C. albicans (90%), A. niger (85%), Enterobacter sp. (75%) and P. aeruginosa (71%). These results suggest the potential use of the biosurfactant as a stabilizer of silver nanoparticles as an antimicrobial agent in different industrial sectors. Furthermore, the in vivo toxicity potential of biosurfactants was evaluated using the Tenebrio molitor model. The larvae were treated with concentrations in the range of 2.5, 5.0 and 10 g/L, and no mortality was observed within the 24 to 72 h period, demonstrating non-toxicity within the tested concentration range. These findings support the safety, efficacy and non-toxicity of biosurfactant-stabilized nanoparticles.

Molecular Characterization of Native Isolates of Metarhizium rileyi (Farlow) Samson (Ascomycetes: Hypocreales) from Major Cropping Ecosystems of Northeastern Karnataka, India

Aims: In India, commercial biopesticides have been recommended against different insect pests on different crops, but their application has shown only a reduced efficiency attributed to differences in susceptibility of target insect pests or non-adaptability to Indian agro-climatic conditions. Therefore, there is a need to isolate region-specific biopesticide strains to enhance the efficacy of such biopesticides for pest management. The current study aimed to explore the new isolates of the entomopathogenic fungus, Metarhizium rileyi (Farlow) Samson species across the major cropping ecosystems of kalyana Karnataka. M. rileyi is an important entomopathogenic fungus of more than 30 species of Lepidoptera larvae. The aim of this research was to characterize the isolate of M. rileyi from Northeastern Karnataka by using morphological and molecular approaches. Methodology: The fungus was isolated from the naturally infected cadavers collected from different cropping ecosystems and it was cultured on Sabouraud’s Maltose Yeast Extract Agar (SMAY) media for morphological characterization, SMY media used for molecular characterization. The vegetative hyphae of fungi were 2-3 µm in diameter and hyaline, septate. The conidia ellipsoidal, smooth, and pale green were observed under the optical microscope. The DNA was isolated using the CTAB method and an internal transcribed spacer (ITS1, ITS4) was used as the primers for the amplification. The amplified products of 650 bp were purified and sequenced at ClustaL W in both directions using the above primers. A consensus sequence was obtained by alignment of the forward and reverse sequences for this region and deposited in GenBank (UASRBC Mr-24, UASRBC Mr-3, UASRBC Mr-20, UASRBC Mr-29, UASRBC Mr-7, UASRBC Mr-18). Result: A BLAST search of the sequence in GenBank revealed a 50-100 percent identity with several strains of M. rileyi (Eg. JQ686668, MN907775 and KJ725726 etc.,). Conclusion: The phylogenetic relationship was derived from comparisons of the ITS gene sequences and a Dendrogram was constructed. The homology and variations based on amino acid sequences among the isolates showed 71 per cent (OK184897) and 51 per cent similarity with four isolates (OK184899, OK177835, OK178862 and OK184898).

Evaluating Mechanisms of Soil Microbiome Suppression of Striga Infection in Sorghum.

The root parasitic weed Striga hermonthica has a devastating effect on sorghum and other cereal crops in Sub-Saharan Africa. Available Striga management strategies are rarely sufficient or not widely accessible or affordable. Identification of soil- or plant-associated microorganisms that interfere in the Striga infection cycle holds potential for development of complementary biological control measures. Such inoculants should be preferably based on microbes native to the regions of their application. We developed a method to assess microbiome-based soil suppressiveness to Striga with a minimal amount of field-collected soil. We previously used this method to identify the mechanisms of microbe-mediated suppression of Striga infection and to test individual microbial strains. Here, we present protocols to assess the functional potential of the soil microbiome and individual bacterial taxa that adversely affect Striga parasitism in sorghum via three major known suppression mechanisms. These methods can be further extended to other Striga hosts and other root parasitic weeds. Key features • This protocol provides a detailed description of the methods used in Kawa et al. [1]. • This protocol is optimized to assess soil suppressiveness to Striga infection by using natural field-collected soil and the same soil sterilized by gamma-radiation. • This protocol is optimized to test bacterial (and not fungal) isolates. • This protocol can be easily extended to other host-parasite-microbiome systems.

Molecular Identification of Fungal Species Isolated from the External Surfaces of Ants Caught from Educational Hospitals in Babol City (2021-2022)

Background. Since the ants play a key role in transmitting microorganisms, it is important to identify the fungal species isolated from the external surfaces of ants caught from hospitals. Therefore, the present study aimed to identify the fungal species isolated from the external surfaces of ants caught from Babol hospitals. Methods. Ants were collected by trapping inside sterile tubes and were washed with normal saline for 20 seconds. Then, 100 µL of the resulting solution was cultured in Sabouraud Dextrose Agar (SDA) medium and incubated for one week at 35C°. Macroscopic, microscopic, and RFLP-PCR molecular techniques were employed to confirm the grown isolates. Results. A total of 79 fungal isolates including 47 isolates of hyaline fungi (59.49%) and 32 isolates of black fungi (40.51%) were obtained from 63 captured ants. Out of 47 cultured fungi, 15 fungi (31.91%) were Aspergillus niger and 15 (31.91%) were A. flavus, 12 (25.53%) were A. fumigatus and 5 isolates were Penicillium (10.63%). Conclusion. Taking into account the increasing number of immunocompromised patients, outbreak of COVID-19 in recent years, and numerous reports about the invasive fungal diseases among COVID-19 patients, it was found necessary to control the ants as carriers of these organisms. Practical Implications. It was necessary to control these insects effectively in order to prevent the increasing prevalence of the fungal diseases among the hospitalized people.

Characterization of Silver Nanoparticles Synthesized With Fungi Isolated From Cocoa and Orange Plantation Soils

Green synthesis of nanoparticles with various metals is being interested among researchers globally attention for due to their safety, environmental friendliness and non-toxicity in contrast to chemical synthesis. Here, fungi were isolated from rhizosphere of cocoa and orange obtained from Federal University of Technology, Akure using standard mycological techniques with the aim of synthesizing silver nanoparticles. The silver nanoparticles synthesized by these fungal isolates were characterized using Ultraviolet-Visible (UV-Vis) and Fourier Transmission Infra- Red (FTIR) spectroscopy. Seven fungi isolated from the soil samples viz. Nigrospora sphaerica, Penicillium discolor, P. digitatum, Neurospora crassa, Alternarium infectoria, Trichophyton verrucosum and Mucor mucedo. The colour transformation from yellow to brown indicated the formation of silver nanoparticles. All the isolates showed an intense peak in the wavelength range of 410-440 nm. The FTIR analysis of silver nanoparticles synthesized by N. sphaerica, P. discolor, P. digitatum, N. crassa, A. infectoria, T. verrucosum and M. mucedo revealed the existence of a band at different stretches of bonds at different peaks of 3314.36 cm-1, 3310.47 cm-1, 2412.22 cm-1, 3912.33 cm-1 3614.52 cm-1, 3852.11 cm-1 and 2112.11 cm-1, respectively. The silver nanoparticles synthesized could have the potential application in agricultural, pharmaceutical and food industries as well as petrochemical industries for the clean - up of crude oil contaminated soils. J. Bio-Sci. 32(2): 31-44, 2024