Characterization and phylogeny of fungi isolated from industrial wastewater using multiple genes

Phylogenetic studies and distinction of aflatoxin-producing Aspergillus species in section Flavi, Ochraceorosei and Nidulantes: A review

Aspergillus species produce polyketides, which form the basis of aflatoxins, some of the most significant mycotoxins in agriculture. Aflatoxins contaminate cereals, oilseeds, and nuts, both in the field and during storage. Of the 13 naturally occurring aflatoxins, the most potent are aflatoxins B1, B2, G1, and G2. The primary aflatoxigenic species are A. flavus, A. parasiticus, and A. nomius, while A. arachidicola, A. minisclerotigenes, and A. saccharicola also documented. These aflatoxin producers belong to three sections- 'Flavi', 'Ochraceorosei', and 'Nidulantes.' Aspergillus flavus, within section Flavi, shows morphological diversity, classified into Group I (S- and L- strains) and Group II (S- strains), with S-strains producing higher levels of aflatoxins. Aflatoxin biosynthesis is primarily regulated by the aflR gene, though other genes like aflS, aflP, aflQ, aflC, and aflM are also associated. However, presence of the aflR gene does not guarantee aflatoxin production across species. Sterigmatocystin serves as a precursor molecule within the pathway leading to aflatoxin production. Phylogenetic assessment, using ITS, BenA, CaM, and RBP2 gene sequences, reveals distinct clusters within Aspergillus sections and highlights the co-evolution of aflatoxigenic and non-aflatoxigenic species. Aspergillus ochraceoroseus and A. rambellii diverged out of aflatoxin-producing species earlier in evolutionary history, before splitting from a shared ancestor with A. fumigatus, which neither produces aflatoxins nor sterigmatocystin. Non-aflatoxigenic species like A. oryzae may evolve from aflatoxigenic species like A. flavus due to variations in evolutionary rates, telomere deletions, and mutations in aflatoxin biosynthesis genes. Comparative genomic analysis of AF, AF/ST and ST gene cluster shows that A. flavus has a larger aflatoxin gene cluster, while A. ochraceoroseus lacks the genes aflP and aflQ. Additionally, A. ochraceoroseus and A. rambellii possess a smaller genome, suggesting that genetic drift and deletions have refined their genomes for more efficient aflatoxin production.

The Potential Proallergenic Activity of Tranzschelia pruni-spinosae and Phragmidium rubi-idaei in vitro Studies

Purpose

Allergic diseases have escalated to epidemic levels worldwide, impacting nearly 30% of the global population. Fungi are a significant source of allergens responsible for up to 6% of respiratory diseases in the general population. However, the specific cause of respiratory allergies often remains unidentified. This study aimed to investigate the potential of two common rust fungi, Tranzschelia pruni-spinosae and Phragmidium rubi-idaei, to trigger a proinflammatory response in vitro models representing the upper and lower respiratory tract.

Materials and Methods

The BEAS-2B and A549 cell lines simulated upper and lower respiratory endothelial cells. The cytotoxicity of fungal extracts was evaluated using MTT and flow cytometry assays. Cell reactive oxygen species (ROS) production was measured via flow cytometry, while ELISA tests quantified the production of proinflammatory cytokines. Immunofluorescence techniques were employed to assess cell integrity markers.

Results

Extracts from T. pruni-spinosae and P. rubi-idaei significantly stimulated the production of proinflammatory cytokines IL-1β and GM-CSF in both cell lines, all of which are associated with the development of allergic responses. The increase in these cytokines and the elevated ROS production were linked to the disruption of epithelial cell junctions.

Conclusion

The findings suggest the potential of T. pruni-spinosae and P. rubi-idaei extracts to collectively disrupt the epithelial barrier in the upper and lower respiratory tract by inducing proinflammatory cytokines and the production of reactive oxygen species and metalloproteinases. Although none of the above parameters was spectacularly high, all of them together could cause a decrease in the presence of tight junction proteins, such as E-cadherin and occludin, in epithelial cells.

Chemical characterization, pathway enrichments and bioactive potentials of catechin-producing endophytic fungi isolated from tea leaves

Endophytes acquire flavonoid biosynthetic genes from the host medicinal plants. Despite tea (Camellia sinensis (L.) Kuntze) being the major source of bioactive catechins, catechin-producing endophytic fungi have never been reported from the tea plant. Here, we report the isolation and characterization of catechin-producing endophytic fungi isolated from tea leaves, their chemical characterization, and associated bioactivities. Among the nine isolated endophytes, two (CSPL6 and CSPL5b) produced catechin (381.48 and 166.40 μg per mg extract) and epigallocatechin-o-gallate (EGCG; 484.41 and 281.99 μg per mg extract) as quantified by high-performance liquid chromatography (HPLC). The isolates were identified as Pseudopestalotiopsis camelliae-sinensis and Didymella sinensis based on molecular and morphological characterization. Untargeted metabolomics using gas-chromatography mass spectroscopy (GCMS) revealed the presence of several bioactive phytochemicals mostly belonging to tyrosols, pyridoxines, fatty acids, aminopyrimidine, and benzenetriol classes. Metabolic pathways pertaining to the biosynthesis of unsaturated fatty acids (UFAs), butanoate metabolism, and linoleic acid metabolism were highly enriched in both catechin-producing isolates. The isolates were able to differentially scavenge intracellular O2 and N2 free-radicals, but CSPL5b demonstrated relatively superior bioactivities compared to CSPL6. Both isolates stimulated the growth of various probiotic strains, indicating prebiotic effects that are otherwise known to be associated with catechins. Collectively, the current study demonstrated that fungal endophytes CSPL6 and CSPL5b, isolated from tea leaves, could be used as alternative sources of catechins, and hold promising potential in evidence-based therapeutics.

Evaluation of the novel endophytic fungus Chaetomium ascotrichoides 1-24-2 from Pinus massoniana as a biocontrol agent against pine wilt disease caused by Bursaphelenchus xylophilus

BACKGROUND

Bursaphelenchus xylophilus, the causative agent of pine wilt disease (PWD), is an ever-increasing threat to Pinus forests worldwide. This study aimed to develop biological control of PWD by the application of endophytic fungi isolated from healthy pine trees.

RESULTS

We successfully isolated a novel endophytic fungal strain 1-24-2 from branches of healthy Pinus massoniana. The culture filtrates (CFs) of strain 1-24-2 exhibited strong nematicidal activity against Bursaphelenchus xylophilus, with a corrected mortality rate of 99.00%. Based on the morphological and molecular characteristics, the isolated strain 1-24-2 was identified as Chaetomium ascotrichoides. In the in-planta assay, pine seedlings (2-years-old) treated with 1-24-2 CFs + pine wood nematode (T2) showed a significant control effect of 80%. A total of 24 toxic compounds were first identified from 1-24-2 CFs through gas chromatography-mass spectrometry (GC-MS) analysis, from which O-methylisourea, 2-chlorobenzothiazole, and 4,5,6-trihydroxy-7-methylphthalide showed robust binding sites at Tyr119 against phosphoethanolamine methyltransferase (PMT) protein of Bursaphelenchus xylophilus by molecular docking approach and could be used as potential compounds for developing effective nematicides. Interestingly, strain 1-24-2 produces toxic volatile organic compounds (VOCs), which disturb the natural development process of B. xylophilus, whose total number decreased by up to 83.32% in the treatment group as compared to control and also reduced Botrytis cinerea growth by up to 71.01%.

CONCLUSION

Our results highlight the potential of C. ascotrichoides 1-24-2 as a promising biocontrol agent with solid nematicidal activity against B. xylophilus. This is the first report of C. ascotrichoides isolated from P. massoniana exhibiting strong biocontrol potential against B. xylophilus in the world. © 2024 Society of Chemical Industry.

Phenol biodegradation using bio-filter tower packed column with immobilized bacterial consortium: a batch test study

The effluents from pulp and paper manufacturing industries contain high concentrations of phenol, which when discharged directly into surface water streams, increases the biological oxygen demand (BOD) and chemical oxygen demand (COD). In this study, two dominant bacteria SP-4 and SP-8 were isolated from the effluent emanating with a pulp and paper industry. The selected phenol-degrading isolates were identified as Staphylococcus sp. and Staphylococcus sciuri respectively by using nucleotide sequence alignment and phylogenetic analysis of 16 S rRNA regions of the genome. The two isolates used for the biodegradation process effectively degraded phenol concentration of pulp and paper industry effluent upto 1600 and 1800 mg/L resepctively. The individual isolates and consortium were immobilized using activated carbon, wood dust, and coal ash. Additionally, the effluent was treated using a bio-filter tower packed column immobilized with bacterial cells at a constant flow rate of 5 mL/min. The present study showed that the developed immobilized microbial consortium can effectively degrade 99% of the phenol present in pulp and paper industry effluents, resulting in a significant reduction in BOD and COD of the system. This study can be well implemented on real-scale systems as the bio-filter towers packed with immobilized bacterial consortium can effectively treat phenol concentrations up to 1800 mg/L. The study can be implemented for bioremediation processes in phenolic wastewater-contaminated sites.

Nanotechnology-Based Strategies to Combat Multidrug-Resistant Candida auris Infections

An emerging multidrug-resistant pathogenic yeast called Candida auris has a high potential to spread quickly among hospitalized patients and immunodeficient patients causing nosocomial outbreaks. It has the potential to cause pandemic outbreaks in about 45 nations with high mortality rates. Additionally, the fungus has become resistant to decontamination techniques and can survive for weeks in a hospital environment. Nanoparticles might be a good substitute to treat illnesses brought on by this newly discovered pathogen. Nanoparticles have become a trend and hot topic in recent years to combat this fatal fungus. This review gives a general insight into the epidemiology of C. auris and infection. It discusses the current conventional therapy and mechanism of resistance development. Furthermore, it focuses on nanoparticles, their different types, and up-to-date trials to evaluate the promising efficacy of nanoparticles with respect to C. auris.

Wastewater surveillance beyond COVID-19: a ranking system for communicable disease testing in the tri-county Detroit area, Michigan, USA

Introduction

Throughout the coronavirus disease 2019 (COVID-19) pandemic, wastewater surveillance has been utilized to monitor the disease in the United States through routine national, statewide, and regional monitoring projects. A significant canon of evidence was produced showing that wastewater surveillance is a credible and effective tool for disease monitoring. Hence, the application of wastewater surveillance can extend beyond monitoring SARS-CoV-2 to encompass a diverse range of emerging diseases. This article proposed a ranking system for prioritizing reportable communicable diseases (CDs) in the Tri-County Detroit Area (TCDA), Michigan, for future wastewater surveillance applications at the Great Lakes Water Authority's Water Reclamation Plant (GLWA's WRP).

Methods

The comprehensive CD wastewater surveillance ranking system (CDWSRank) was developed based on 6 binary and 6 quantitative parameters. The final ranking scores of CDs were computed by summing the multiplication products of weighting factors for each parameter, and then were sorted based on decreasing priority. Disease incidence data from 2014 to 2021 were collected for the TCDA. Disease incidence trends in the TCDA were endowed with higher weights, prioritizing the TCDA over the state of Michigan.

Results

Disparities in incidences of CDs were identified between the TCDA and state of Michigan, indicating epidemiological differences. Among 96 ranked CDs, some top ranked CDs did not present relatively high incidences but were prioritized, suggesting that such CDs require significant attention by wastewater surveillance practitioners, despite their relatively low incidences in the geographic area of interest. Appropriate wastewater sample concentration methods are summarized for the application of wastewater surveillance as per viral, bacterial, parasitic, and fungal pathogens.

Discussion

The CDWSRank system is one of the first of its kind to provide an empirical approach to prioritize CDs for wastewater surveillance, specifically in geographies served by centralized wastewater collection in the area of interest. The CDWSRank system provides a methodological tool and critical information that can help public health officials and policymakers allocate resources. It can be used to prioritize disease surveillance efforts and ensure that public health interventions are targeted at the most potentially urgent threats. The CDWSRank system can be easily adopted to geographical locations beyond the TCDA.

Diversity, Lifestyle, Genomics, and Their Functional Role of Cochliobolus, Bipolaris, and Curvularia Species in Environmental Remediation and Plant Growth Promotion under Biotic and Abiotic Stressors

Cochliobolus, Bipolaris, and Curvularia genera contain various devastating plant pathogens that cause severe crop losses worldwide. The species belonging to these genera also perform a variety of diverse functions, including the remediation of environmental contaminations, beneficial phytohormone production, and maintaining their lifestyle as epiphytes, endophytes, and saprophytes. Recent research has revealed that despite their pathogenic nature, these fungi also play an intriguing role in agriculture. They act as phosphate solubilizers and produce phytohormones, such as indole acetic acid (IAA) and gibberellic acid (GAs), to accelerate the growth of various plants. Some species have also been reported to play a significant role in plant growth promotion during abiotic stresses, such as salinity stress, drought stress, heat stress, and heavy metal stress, as well as act as a biocontrol agent and a potential mycoherbicide. Similarly, these species have been reported in numerous industrial applications to produce different types of secondary metabolites and biotechnological products and possess a variety of biological properties, such as antibacterial, antileishmanial, cytotoxic, phytotoxic, and antioxidant activities. Additionally, some of the species have been utilized in the production of numerous valuable industrial enzymes and biotransformation, which has an impact on the growth of crops all over the world. However, the current literature is dispersed, and some of the key areas, such as taxonomy, phylogeny, genome sequencing, phytohormonal analysis, and diversity, are still being neglected in terms of the elucidation of its mechanisms, plant growth promotion, stress tolerance, and bioremediation. In this review, we highlighted the potential role, function, and diversity of Cochliobolus, Curvularia, and Bipolaris for improved utilization during environmental biotechnology.