Putative Fungi Research Articles

Screening, characterization and optimization of potential dichlorodiphenyl trichloroethane (DDT) degrading fungi

Dichlorodiphenyltrichloroethane is an organo-chlorine insecticide used for malaria and agricultural pest control, but it is the most persistent pollutant, endangering both human and environmental health. The primary aim of the research is to screen, characterize, and assess putative fungi that degrade DDT for mycoremediation. Samples of soil and wastewater were gathered from Addis Ababa, Koka, and Ziway. Fungi were isolated and purified using potato dextrose media. Matrix-Assisted Laser Desorption, Ionization, and Flight Duration The technique of mass spectrometry was employed to identify fungi. It was found that the finally selected isolate, AS1, was Aspergillus niger. Based on growth factor optimization at DDT concentrations (0, 3500, and 7000 ppm), temperatures (25, 30, and 35 °C), and pH levels (4, 7, and 10), the potential DDT-tolerant fungal isolates were investigated. A Box-Behnken experimental design was used to analyze and optimize fungal biomass and sporulation. The highest biomass (0.981 ± 0.22 g) and spore count (5.60 ± 0.32 log/mL) of A. niger were found through optimization assessment, and this fungus was chosen as a potential DDT-degrader. For DDT degradation investigations by A. niger in DDT-amended liquid media, gas chromatograph-electron capture detector technology was employed. DDT and its main metabolites, DDE and DDD, were eliminated from both media to the tune of 96–99 % at initial DDT concentrations of 1750, 3500, 5250, and 7000 ppm. In conclusion, it is a promising candidate for detoxifying and/or removing DDT and its breakdown products from contaminated environments.

Profiling of fungi associated with Lycopersicum esculentum mill. spoilage in Nigeria using internal transcribed spacer (its) sequence of rDNA method

Lycopersicum esculentum Mill often referred to as Tomato is among important vegetable fruits widely cultivated the world over. The fruits are made up of soft endocarp which make them susceptible to spoilage by fungi mold. The fungi produce mycotoxins that are injurious and detrimental to human health. This study is aimed at profiling fungi mold associated with Lycopersicum esculentum rot /spoilage and identify the putative fungi responsible for its spoilage in Nigeria, particularly Akwa Ibom State metropolis. Tomato fruits heavily infested with fungi mold were collected and marshed using a sterile electric blender. Serial dilution of sample in normal saline were made and grown on prepared plates of Potato Dextrose Agar (PDA) to obtain pure culture. High quality genomic DNA was isolated from the samples; it was quantified and checked for purity. The DNA samples were subjected to PCR amplification. The amplicons were gel eluted, sequenced and checked for homology by using Basic local alignment search tool - BLAST. Identification was obtained from the top similarility outcomes of the samples. Four fungal isolates identified were Aspergilus spp., Fusarium spp., Mucor spp. and Penicillium citrinium. The economic importance of fungi molds are not in doubt as some of them are important precursor of diseases as they produces mycotoxins which is capable of causing diseases in both humans and animals, while other sare important in the field of medicine, in industrial production of antibiotics especially Penicillin.

Characterization of Macrophomina phaseolina associated with leaf blight disease on Chlorophytum borivilianum Santapau & R.R. Fern. and its fungicidal susceptibility

Safed musli, Chlorophytum borivilianum Santapau & R.R. Fern. is an important medicinal plant due to aphrodisiac and immuno-modulatory properties. Leaf blight disease showing characteristic symptom of necrosis spots on tips and outer margin of leaves, which gradually progressed and cover large portion of leaf lamina. Severe infection causes premature drying of leaves, which give blighted appearance as observed on safed musli growing field of ICAR-Directorate of Medicinal and Aromatic Plants Research, Anand, Gujarat (India). Associated putative fungus was isolated from single microsclerotia and characterized through cultural, morphological and microscopic studies. The association of putative fungus confirmed by pathogenicity test on potted safed musli plants. Mycelium of the causative organism showed dark olive black colonies that ultimately turns black and were found embedded with abundant of microsclerotia. Morphologically microsclerotia were black, smooth, round to oblong, 49.88 - 99.74 ± 5.62 μm in diameter. Pycnidia were exclusively observed on the infected leaves of C. borivilianum, were dark to greyish, globose, membranous and 83.62- 123.88 ± 3.77 μm in diameter. Conidia were single celled, hyaline, aseptate, obovoid and measuring 13.83 - 17.28 ± 0.37 μm × 5.39 - 7.28 ± 0.28 μm. By comparing with available relevant literature, the fungus was tentative identified as Macrophomina phaseolina. The identity of associated pathogen was further confirmed by molecular sequencing of internal transcribed spacer (ITS) of rDNA region and actin gene. In vitro efficacy test showed that among the tested fungicides, metalaxyl 4.0% + mancozeb 64% causes highest mycelial growth inhibition (90.00%) at both, 0.1 and 0.2% concentration and of Pseudomonas fluorescence (PF7) showed 51.72% mycelial growth inhibition.

First report of Diplodia seriata de Not. causing black rot of apple (Malus domestica L. Borkh.) in Meghalaya, North Eastern India

In a survey conducted during Januray-May, 2020, apple trees showing characteristic symptoms of frogeye leaf spots, canker and twig die back that in severe cases causing dead branches and severe defoliation have been observed from apple plantation of Umiam, Meghalaya. Isolation of the associated causal fungal agent was done in selective media and its cultural, morphological as well as microscopical studies were carried out. Furthermore, confirmation of the putative fungus was done by conducting pathogenicity test to prove Koch’s postulate. From the available literature, the fungus associated with the disease symptom have been identified as Diplodia seriata causing black rot of apple. To the best of the knowledge, this is the first report of isolation and pathogenicity confirmation of black rot of apple caused by D. seriata from Meghalaya, India.

Prasinophyte bloom and putative fungi abundance near the Kačák event (Middle Devonian) from the Odivelas Limestone, Southwest Iberia

The Kacak Event is one of the several prominent Devonian climatic and biotic perturbations with a supra-regional to global extent. Its record can be traced in the litho- and biostratigraphy of uppermost Eifelian-lowermost Givetian strata and with multiple geochemical and geophysical proxies. In southwest Iberia, within southwestern Ossa-Morena Zone domains, there are rare, scattered Early-Middle Devonian limestone occurrences. One of these occurrences—the Odivelas Limestone type locality—is revisited in terms of conodont biostratigraphy and palynology and the results compared with previous data on reef macrofauna and magnetic susceptibility stratigraphy. The new data show that this locality is probably within the Polygnathus hemiansatus zone, i.e. of the earliest Givetian age. The palynological content of a ca. 2 m of black, organic-rich, fine grained limestone section is dominated, in varied proportions, by amorphous organic matter, putative fungal hyphae, and prasinophycean algae. The results are interpreted as an indication of high organic productivity and deposition in hypoxic to anoxic settings and probable biotic crisis, in both marine and terrestrial realms, connected with the Middle Devonian Kacak Event. The similarity of this record with other Devonian events is discussed.

A role for fungi as parasites in the black box of marine trophic interactions.

The role of microbial parasites in aquatic environments remains under-investigated and likely under-estimated limiting our understanding of trophic interactions and biogeochemical cycles (Lefèvre et al., ; Worden et al., ). All natural interactions between microbes are difficult to capture and study but those occurring in the open ocean more so, because the scale and the complexity of the system makes repeat sampling a challenge. Lepère and colleagues, by combining a range of cell recovery and detection techniques, have identified parasitic interactions between putative fungi and eukaryotic algae (Lepère et al., ) allowing us to peer into the black box of microbial parasitism in the marine water column.

Probable Proterozoic fungi

Abstract A large, morphologically heterogeneous population of acanthomorphic acritarchs from the early Neoproterozoic Wynniatt Formation, Victoria Island, northwestern Canada, is ascribed to two form-genera, Tappania and Germinosphaera, but just a single natural taxon, Tappania. Analysis of Tappania morphology shows it to have been an actively growing, benthic, multicellular organism capable of substantial differentiation. Most notably, its septate, branching, filamentous processes were capable of secondary fusion, a synapomorphy of the “higher fungi.” Combined with phylogenetic, taphonomic and functional morphologic evidence, such “hyphal fusion” identifies Tappania reliably, if not conclusively, as a fungus, probably a sister group to the “higher fungi,” but more derived than the zygomycetes. The presence of Tappania in the Mesoproterozoic Roper Group of Australia extends the record of putative fungi to 1430 Ma. Along with other Proterozoic acritarchs exhibiting fungus-like characteristics (e.g., Trachy...

Emergence and partial characterization of rice stripe necrosis virus and its fungus vector in South America.

A new disease of rice, known as ‘entorchamiento’ (crinkling), was first noticed in the Department of Meta, Colombia, in 1991. Symptoms include seedling death, foliar striping and severe plant malformation. Tissue extracts and purified preparations from diseased rice plants, contained virus-like particles ca. 20 nm in diameter, with a bimodal length of 260 and 360 nm. Particle aggregates were also observed in the cytoplasm of infected rice leaf cells. Electrophoretic analyses of purified preparations and dsRNA extracts, revealed a single protein species of M 22,500, and four dsRNA bands ca. 6300, 4600, 2700 and 1800 bp in size. Cystosori, characteristic of plasmodiophorid fungal vectors of plant viruses, were consistently observed in the roots of diseased rice plants. PCR and sequence analyses of amplified fungal DNA products from infected rice roots, revealed that the putative fungus vector was Polymyxa graminis. A Western blot of tissue extracts obtained from ‘crinkled’ rice plants from Colombia, using antiserum against a West African isolate of rice stripe necrosis furovirus (RSNV), resulted in the detection of a protein band of approximately M 22,000. The RSNV antiserum recognized the Colombian virus isolate in serologically specific electron microscopy tests. These results confirm the presence of RSNV in the Americas.