Medical Mycology: Open Access

Description

Aspergillus is a diverse group of filamentous, cosmopolitan fungi that thrive in virtually all natural and man-made substrates. Due to their significance in medical and industrial mycology, these fungi are extensively studied and have a significant impact on contemporary society. Raper and Fennell identified 150 species, and more than 340 Aspergillus species are currently classified into four subgenera and 19 sections. Black aspergillus is one of the most studied groups due to its significant biotechnological and industrial potential. They are part of the subgenus Circumdati, which includes 26 species that are classified as A. niger, A. carbonarius, A. heteromorphus, A. homomorphus, and A. acualeatus, respectively. Previously, most fungal identification criteria were macro- and micromorphological. However, molecular identification, which compares specific genes or partial sequences and is referred to as molecular markers, has made it easier to identify taxa in the genus Aspergillus. Multiple locus identification has been proposed for Aspergillus species identification. This method makes use of ITS in addition to the molecular markers for betatubulin (Bt), calmoduline (CMD), and transcriptional elongation factor 1 (Tef). Unfortunately, species belonging to section Nigri cannot always be identified using this method of multiple locus identification. As a result, it has been suggested that a polyphasic method be used to define, identify, and describe Aspergillus species. DNA sequences, morphological, physiological, and ecological data, and extrolite analysis are all used in the polyphasic identification to arrive at a consensus result with greater fidelity and robustness. Additionally, the polyphasic focus prevents mistakes that could have been made using only morphological or/and molecular methods. For various fungal groups that adapt to more significant characters, reference protocols for polyphasic identification have been proposed, and several prestigious laboratories offer this kind of identification. Polyphasic Identification, a free online tool from the Westerdikj Fungal Biodiversity Institute (previously CBS), can be used to identify Aspergillus, Penicillium, and yeast species by comparing user data with CBS-KNAW, the institute's database, in order to identify a fungal isolate using a polyphasic approach.

Host-Pathogen Interaction

Enzymatic production is one of the most common uses for species of Aspergillus section Nigri that have been used in various industrial bioprocesses. Due to their widespread industrial application, cellulose-degrading enzymes have received extensive research. EGs generate reducing and nonreducing ends that are attached by CBHI and CBHII, respectively, releasing cellobioses, which are then hydrolyzed by BGLs after EGs act on cellulose's -1,4-glucosidic bonds. Cellulases and cellulolytic organisms can benefit from research on cellulosic biomass processing. Through a focus on biotechnology, we could learn more about new fungi isolates and produce effective enzymes for use in industry. A polyphasic method for identifying an Aspergillus isolate from the Paranaense rainforest was used in this study to investigate its cellulolytic potential and its potential for biotechnological applications. The symptoms of rice blast depend on the host plant's resistance and age in the environment. The pathogen primarily affects foliage, causing blasting on the necks and panicles during the vegetative growth phase or during the reproductive stage. In the case of blast of the neck, which is typically characterized by an infection at the panicle's base and its rotting, these symptoms are extreme. The disease is brought on by M. oryzae, a heterothallic ascomycete that lives in structures called asci and produces asexual or sexual spores (ascospores). The pathogen begins infection through a prolonged biotrophic stage, during which the fungus grows within host cells before moving on to a necrotrophic stage that results in the development of a lesion. This stage is bounded by the plasma membrane of the invaginated plant. Branched, septate, and uninucleate hyphae make up the mycelium. Septate conidiophores with a dark base that acrogenously form hyaline and pyriform conidia. The pathogen causes leaf blast, leaf collar blast, culm blast, panicle neck rot, and panicle blast on leaves, culms, and panicles. The plant's developmental stage and the environment influence the color and shape of these lesions.

Pathogenesis and infection cycle

Volatile compounds are a group of metabolites that are known to play a significant role in a distant antagonism interaction. However, little is known about the effects of interspecific interactions between ectomycorrhizal and saprotrophic fungi on the production of volatiles. During the fungal interaction's time course, at three days (without inhibition), eight days (inhibition with statistical significance), and fourteen days (maximal inhibition), the production of volatile organic compounds (VOCs) by Pt-Hf interaction and corresponding controls (Pt-Pt and Hf-Hf) was monitored in this study. Formally and tentatively identified VOCs belong to distinct chemical classes, the three dual cultures produce VOCs that are qualitatively and semi-quantitatively distinct from one another. The changing trend of each individual VOC during fungal interactions was evaluated for the purpose of comprehending the dynamics of VOC production over time and the potential function of antagonistic compounds. In contrast to the controls' Hf-Hf and Pt-Pt interactions, any compound was produced de novo in this study. However, VOC production underwent significant shifts at various interaction stages. The untargeted PCA analysis of the pre-processed raw data allowed for the differentiation of volatile profiles after 8 and 14 days in Pt-Hf and Hf-Hf interactions, whereas all volatile profiles derived from all Pt-Pt interaction periods and after 3 days of co-cultures remained undifferentiated. When the two principal components (PC1 and PC2) are taken into account, a PCA with 41 variables (peak areas of 41 compounds) reveals a variance of 78.07% higher. Due to their communality values below 0.56, the variables 3-methylbutanoic acid, 6-methyl-5-hepten-2-one, menthol, longifolene, 1,4-dichlorobenzene, toluene, ethylbenzene, and -xylene were not included in the subsequent target analysis. The clear differentiation between Pt-Hf and Hf-Hf interactions over time was supported by the representation of variables and fungal interactions over 3, 8, and 14 days using the first two PCs of targeted analysis. After 8 and 14 days of interaction, both PCA approaches produced scores with similar distribution patterns, confirming the strong relationship between Pt-Hf and Hf-Hf. After 14 days of interaction, the unidentified nitrogen-like compound 1 and fungal cultures are positively correlated with the first principal component (PC1), which accounts for 98.23 percent of the total variance. With - muurolene, naphthalene, and cultures after eight days of interaction, there is a positive correlation between the second principal component (PC2), which accounts for 0.98 percent of the total variance. Pt collaborations at 3, 8 and 14 days are set nearer in the projection, adversely connected with PC1 and PC2.