Mycelial pellet formation by Penicillium ochrochloron species due to exposure to pyrene

Three strategy rules of filamentous fungi in hydrocarbon remediation: an overview

Remediation of hydrocarbon contaminations requires much attention nowadays since it causes detrimental effects on land and even worse impacts on aquatic environments. Tools of bioremediation especially filamentous fungi permissible for cleaning up as much as conceivable, at least they turn into non-toxic residues with less consumed periods. Inorganic chemicals, CO2, H2O, and cell biomass are produced as a result of the breakdown and mineralization of petroleum hydrocarbon pollutants. This paper presents a detailed overview of three strategic rules of filamentous fungi in remediating the various aliphatic, and aromatic hydrocarbon compounds: utilizing carbons from hydrocarbons as sole energy, Co-metabolism manners (Enzymatic and Non-enzymatic theories), and Biosorption approaches. Upliftment in the degradation rate of complex hydrocarbon by the Filamentous Fungi in consortia scenario we can say, "Fungal Talk", which includes a variety of cellular mechanisms, including biosurfactant production, biomineralization, and precipitation, etc., This review not only displays its efficiency but showcases the field applications - cost-effective, reliable, eco-friendly, easy to culture as biomass, applicable in both land and any water bodies in operational environment cleanups. Nevertheless, the potentiality of fungi-human interaction has not been fully understood, henceforth further studies are highly endorsed with spore pathogenicity of the fungal species capable of high remediation rate, and the gene knockout study, if the specific peptides cause toxicity to any living matters via Genomics and Proteomics approaches, before application of any in situ or ex situ environments.

A novel mycelial pellet applied to remove polycyclic aromatic hydrocarbons: High adsorption performance & its mechanisms

Mycelial pellets formed by Penicillium thomii ZJJ were applied as efficient biosorbents for the removal of polycyclic aromatic hydrocarbons (PAHs), which are a type of ubiquitous harmful hydrophobic pollutants. The live mycelial pellets were able to remove 93.48 % of pyrene at a concentration of 100 mg/L within 48 h, demonstrating a maximum adsorption capacity of 285.63 mg/g. Meanwhile, the heat-killed one also achieved a removal rate of 65.01 %. Among the six typical PAHs (pyrene, phenanthrene, fluorene, anthracene, fluoranthene, benzo[a]pyrene), the mycelial pellets preferentially adsorbed the high molecular weight PAHs, which also have higher toxicity, resulting in higher removal efficiency. The experimental results showed that the biosorption of mycelial pellets was mainly a spontaneous physical adsorption process that occurred as a monolayer on a homogeneous surface, with mass transfer being the key rate-limiting step. The main adsorption sites on the surface of mycelia were carboxyl and N-containing groups. Extracellular polymeric substances (EPS) produced by mycelial pellets could enhance adsorption, and its coupling with dead mycelia could achieve basically the same removal effect to that of living one. It can be concluded that biosorption by mycelial pellets occurred due to the influence of electrostatic and hydrophobic interactions, consisting of five steps. Furthermore, the potential applicability of mycelial pellets has been investigated considering diverse factors. The mycelia showed high environmental tolerance, which could effectively remove pyrene across a wide range of pH and salt concentration. And pellets diameters and humic acid concentration had a significant effect on microbial adsorption effect. Based on a cost-effectiveness analysis, mycelium pellets were found to be a low-cost adsorbent. The research outcomes facilitate a thorough comprehension of the adsorption process of pyrene by mycelial pellets and their relevant applications, proposing a cost-effective method without potential environmental issues (heat-killed mycelial pellets plus EPS) to removal PAHs.

Enhancing Monascus Pellet Formation for Improved Secondary Metabolite Production

Filamentous fungi are well-known for their ability to form mycelial pellets during submerged cultures, a characteristic that has been extensively studied and applied. However, Monascus, a filamentous saprophytic fungus with a rich history of medicinal and culinary applications, has not been widely documented for pellet formation. This study aimed to investigate the factors influencing pellet formation in Monascus and their impact on citrinin production, a key secondary metabolite. Through systematic exploration, we identified pH and inoculum size as critical factors governing pellet formation. Monascus exhibited optimal pellet growth within the acidic pH range from 5 to 6, resulting in smaller, more homogeneous pellets with lower citrinin content. Additionally, we found that inoculum size played a vital role, with lower spore concentrations favoring the formation of small, uniformly distributed pellets. The choice of carbon and nitrogen sources also influenced pellet stability, with glucose, peptone, and fishmeal supporting stable pellet formation. Notably, citrinin content was closely linked to pellet diameter, with larger pellets exhibiting higher citrinin levels. Our findings shed light on optimizing Monascus pellet formation for enhanced citrinin production and provide valuable insights into the cultivation of this fungus for various industrial applications. Further research is warranted to elucidate the molecular mechanisms underlying these observations.

Microbiome based approaches for the degradation of polycyclic aromatic hydrocarbons (PAHs): A current perception

Globally, polycyclic aromatic hydrocarbons (PAHs) pollution is primarily driven by their release into the air through various combustion processes, including burning fossil fuels such as coal, oil, and gas in motor vehicles, power plants, and industries, as well as burning organic matter like wood, tobacco, and food in fireplaces, cigarettes, and grills. Apart from anthropogenic pollution sources, PAHs also occur naturally in crude oil, and their potential release during oil extraction, refining processes, and combustion further contributes to contamination and pollution concerns. PAHs are resistant and persistent in the environment because of their inherent features, viz., heterocyclic aromatic ring configurations, hydrophobicity, and thermostability. A wide range of microorganisms have been found to be effective degraders of these recalcitrant contaminants. The presence of hydrocarbons as a result of numerous anthropogenic activities is one of the primary environmental concerns. PAHs are found in soil, water, and the air, making them ubiquitous in nature. The presence of PAHs in the environment creates a problem, as their presence has a detrimental effect on humans and animals. For a variety of life forms, PAH pollutants are reported to be toxic, carcinogenic, mutation-inducing, teratogenic, and immune toxicogenics. Degradation of PAHs via biological activity is an extensively used approach in which diverse microorganisms (fungal, algal, clitellate, and protozoan) and plant species and their derived composites are utilized as biocatalysts and biosurfactants. Some microbes have the ability to transform and degrade these PAHs, allowing them to be removed from the environment. The goal of this review is to provide a critical overview of the existing understanding of PAH biodegradation. It also examines current advances in diverse methodologies for PAH degradation in order to shed light on fundamental challenges and future potential.

The Deciphering of Growth-Dependent Strategies for Quorum-Sensing Networks in Pseudomonas aeruginosa

Pseudomonas aeruginosa is recognized as a significant cause of morbidity and mortality among nosocomial pathogens. In respiratory infections, P. aeruginosa acts not only as a single player but also collaborates with the opportunistic fungal pathogen Aspergillus fumigatus. This study introduced a QS molecule portfolio as a potential new biomarker that affects the secretion of virulence factors and biofilm formation. The quantitative levels of QS molecules, including 3-o-C12-HSL, 3-o-C8-HSL, C4-HSL, C6-HSL, HHQ, PQS, and PYO, measured using mass spectrometry in a monoculture, indicated metabolic changes during the transition from planktonic to sessile cells. In the co-cultures with A. fumigatus, the profile of abundant QS molecules was reduced to 3-o-C12-HSL, C4-HSL, PQS, and PYO. A decrease in C4-HSL by 50% to 170.6 ± 11.8 ng/mL and an increase 3-o-C12-HSL by 30% up to 784.4 ± 0.6 ng/mL were detected at the stage of the coverage of the hyphae with bacteria. Using scanning electron microscopy, we showed the morphological stages of the P. aeruginosa biofilm, such as cell aggregates, maturated biofilm, and cell dispersion. qPCR quantification of the genome equivalents of both microorganisms suggested that they exhibited an interplay strategy rather than antagonism. This is the first study demonstrating the quantitative growth-dependent appearance of QS molecule secretion in a monoculture of P. aeruginosa and a co-culture with A. fumigatus.

Filamentous fungi for sustainable remediation of pharmaceutical compounds, heavy metal and oil hydrocarbons

This review presents a comprehensive summary of the latest research in the field of bioremediation with filamentous fungi. The main focus is on the issue of recent progress in remediation of pharmaceutical compounds, heavy metal treatment and oil hydrocarbons mycoremediation that are usually insufficiently represented in other reviews. It encompasses a variety of cellular mechanisms involved in bioremediation used by filamentous fungi, including bio-adsorption, bio-surfactant production, bio-mineralization, bio-precipitation, as well as extracellular and intracellular enzymatic processes. Processes for wastewater treatment accomplished through physical, biological, and chemical processes are briefly described. The species diversity of filamentous fungi used in pollutant removal, including widely studied species of Aspergillus, Penicillium, Fusarium, Verticillium, Phanerochaete and other species of Basidiomycota and Zygomycota are summarized. The removal efficiency of filamentous fungi and time of elimination of a wide variety of pollutant compounds and their easy handling make them excellent tools for the bioremediation of emerging contaminants. Various types of beneficial byproducts made by filamentous fungi, such as raw material for feed and food production, chitosan, ethanol, lignocellulolytic enzymes, organic acids, as well as nanoparticles, are discussed. Finally, challenges faced, future prospects, and how innovative technologies can be used to further exploit and enhance the abilities of fungi in wastewater remediation, are mentioned.

A review on mycelial pellets as biological carriers: Wastewater treatment and recovery for resource and energy

Mycelial pellets, a new environment friendly biological carrier, have received wide attention from researchers due to porosity, stability and unique biocompatibility. In this article, the theoretical basis and mechanism of mycelial pellets as a biological carrier were analyzed from the properties of mycelial pellets and the interaction between mycelial pellets and other microorganisms. This article aims to collate and present the current application and development trend of mycelial pellets as biological carriers in wastewater treatment, resource and energy recovery, especially the symbiotic particle system formed by mycelial pellets and microalgae is an important way to break through the technical bottleneck of biodiesel recovery from wastewater. This review also analyzes the research hotspots and trends of mycelial pellets as carriers in recent years, discusses the challenges faced by this technology, and puts forward corresponding solutions.

Pyrene remediation by Trametes maxima: an insight into secretome response and degradation pathway

The rapid pace of economic development has resulted in the release of several polycyclic aromatic hydrocarbons (PAHs) into the environment. Microbial degradation using white-rot fungi is a promising method for the removal of PAHs from the environment. In the present study, biodegradation of recalcitrant PAH by a white-rot fungus, Trametes maxima IIPLC-32, was investigated using pyrene. The pyrene concentration decreased by 79.80%, 65.37%, and 56.37% within 16 days from the initial levels of 10 mg L^-1, 25 mg L^-1, and 50 mg L^-1, respectively. Gas chromatographic-mass spectrometric identification of prominent metabolites 1-hydroxypyrene, 2-methyl-1-naphthyl acetic acid, di-n-butyl phthalate, and diethyl phthalate helped in determining the pyrene degradation pathway. The presence of 81 extracellular proteins was revealed by secretome analysis. The identified proteins up-regulated in response to pyrene degradation were classified into detoxification proteins (6.12%), redox proteins (6.12%), stress proteins (4.08%), metabolic-related proteins (26.53%), translation and transcriptional proteins (49%), catalytic proteins (49%), and other proteins (8.16%). Knowledge of secretome analysis in pyrene degradation helped to understand the degradation mechanism of pyrene. Also, the study suggests that T. maxima IIPLC-32 has the potential to be used in the bioremediation of PAH contaminated aquatic environment.

Methane Generation from Anthracite by Fungi and Methanogen Mixed Flora Enriched from Produced Water Associated with the Qinshui Basin in China

Biogenic coalbed methane (CBM) is generally believed to be formed by anaerobic bacteria and methanogens, while a few studies took fungi into account. Here, the microflora consisting of fungi and methanogens was enriched from the produced water associated with the Qinshui Basin using anthracite as the only carbon source. The maximum methane yield of 231 μmol/g coal was obtained after 22 days of cultivation under the optimum temperature of 35 °C, pH of 8, salinity of 0-2%, particle size of 0.075-0.150 mm, and the solid-liquid ratio of 1:30. It could remain active even after exposure to air for 24 h. Miseq results showed that the archaea were mainly composed of Methanocella, a hydrogenotrophic methanogen, followed by acetoclastic methanogen Methanosaeta and Methanosarcina, which could use various methanogenic substrates. The fungal communities mainly included Amorphotheca, Alternaria, Aspergillus, and Penicilium, which are all able to degrade complex organics such as aromatics and lignin. After cultivation, the crystal structure of anthracite became looser, as shown by XRD results, which might be due to the swelling effect caused by the destruction of the aromatic ring structure of coal under the function of fungi. The stretching vibration intensity of each functional group in coal decreased with cultivation, as revealed by FTIR. The GC-MS results showed that the concentration of alkanes and alcohols decreased significantly, which are the products of ring-opening of aromatics by fungi. These results suggested that fungi and methanogens in the coalbed also can syntrophically degrade coal effectively, especially for aromatics in coal.

Extra-Heavy Crude Oil Degradation by Alternaria sp. Isolated from Deep-Sea Sediments of the Gulf of Mexico

The Gulf of Mexico (GoM) is an important source of oil for the United States and Mexico. There has been growing interest, particularly after the Deepwater Horizon oil spill, in characterizing the fungal diversity of the GoM and identifying isolates for use in the bioremediation of petroleum in the event of another spill. Most studies have focused on light crude oil bioremediation processes, while heavy crude oil (HCO) and extra-heavy crude oil (EHCO) have been largely ignored. In this work, we evaluated the ability of fungal isolates obtained from deep-sea sediments of the Mexican economic exclusive zone (EEZ) of the GoM to degrade HCO (16–20° API) and EHCO (7–10° API). Alternaria sp., Penicillium spp., and Stemphylium sp. grew with HCO as the sole carbon source. Remarkably, Alternaria sp. was the only isolate able to grow with EHCO as the sole carbon source, degrading up to 25.6% of the total EHCO and 91.3% of the aromatic fraction, as demonstrated by gas chromatography analysis of the saturate, aromatic, and polar fractions. These findings proved to be significant, identifying Alternaria sp. as one of the few fungi reported so far capable of degrading untreated EHCO and as a suitable candidate for bioremediation of EHCO in future studies.

Biodegradation of C20 carbon clusters from Diesel Fuel by Coriolopsis gallica: optimization, metabolic pathway, phytotoxicity

This study is to test the capacity of the white rot fungus Coriolopsis gallica for the biodegradation of Diesel Fuel hydrocarbons (DHs). Using the experimental face centered central composite design (FCCCD), culture conditions of the Diesel-mended medium were optimized to reach 110.43% of DHs removal rate, and l5267.35 U L-1 of laccase production by C. gallica, simultaneously. The optimal combination of the cultural parameters was: Diesel concentration range of 2.95-3.14%, inoculum size of 3%, incubation time of 15 days, Tween 80 concentration of 0.05%, and the ratio glucose/peptone (G/P) range of 10.15-10.27. Further, the degradation ability of C. gallica for Diesel Fuel was evaluated through mycelial pellets uptake and oxidative action of fungal enzymes in the optimized degrading-medium using gas chromatography-mass spectrometry (GC-MS). Cyclosiloxanes and C20 PAHs detected as the major compound in Diesel Fuel (46%) was completely bio-transformed to simple metabolites including, essentially benzoic acid ester (71%), alcohols (1.52%) epoxy alkane (1.07%), carboxylic acids (1.24%) and quinones (0.33%). Germination rate and root elongation, as a rapid phytotoxicity test demonstrated that toxicity of Diesel's PAHs is minimized by fungal treatment.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13205-021-02769-w.

A novel strain of Aureobasidium sp. TeO12 for theophylline production from caffeine

A total of 40 fungal cultures were isolated for their ability to grow on caffeine as a sole source carbon and nitrogen, and further screened for theophylline-producing activities under the growing cell system. Based on thin-layer chromatography and high-performance liquid chromatography analyses, the potent strain Aureobasidium sp. TeO12 was chosen for its capability to generate theophylline via biotransformation of caffeine. It was identified based on phenotypic characteristics and its ITS1-5.8S-ITS2 rDNA sequencing data (GenBank accession number no. KT439072). To improve theophylline yield, the effects of various factors, such as resting cell density, Fe(II) concentration, and course of the transformation of caffeine, were studied in a biotransformation reaction containing 0.1 M sodium phosphate buffer (pH 7), Aureobasidium sp. TeO12 resting cells as the whole-cell catalyst and caffeine (2.5 g/L) as the substrate, and the reaction was incubated at 30 °C on an orbital shaker (200 rpm). The results indicated that optimal combination included resting cell density 6 g/L, Fe(II) concentration 75 mg/L, and the biotransformation time 72 h. Under these optimal reaction conditions, the highest theophylline concentration of 1.55 g/L (molar yield of 67%) with an average degradation yield of the substrate of about 83% was obtained in the biotransformation process. This is the first report on the biotransformation of caffeine into theophylline by a novel strain of the genus Aureobasidium.

Mycelial pellet formation by edible ascomycete filamentous fungi, Neurospora intermedia

Pellet formation of filamentous fungi in submerged culture is an imperative topic of fermentation research. In this study, we report for the first time the growth of filamentous ascomycete fungus, Neurospora intermedia in its mycelial pellet form. In submerged culture, the growth morphology of the fungus was successfully manipulated into growing as pellets by modifying various cultivation conditions. Factors such as pH (2.0–10.0), agitation rate (100–150 rpm), carbon source (glucose, arabinose, sucrose, and galactose), the presence of additive agents (glycerol and calcium chloride) and trace metals were investigated for their effect on the pellet formation. Of the various factors screened, uniform pellets were formed only at pH range 3.0–4.0, signifying it as the most influential factor for N. intermedia pellet formation. The average pellet size ranged from 2.38 ± 0.12 to 2.86 ± 0.38 mm. The pellet formation remained unaffected by the inoculum type used and its size showed an inverse correlation with the agitation rate of the culture. Efficient glucose utilization was observed with fungal pellets, as opposed to the freely suspended mycelium, proving its viability for fast-fermentation processes. Scale up of the pelletization process was also carried out in bench-scale airlift and bubble column reactors (4.5 L).

Effects of selenium oxyanions on the white-rot fungus Phanerochaete chrysosporium

The ability of Phanerochaete chrysosporium to reduce the oxidized forms of selenium, selenate and selenite, and their effects on the growth, substrate consumption rate, and pellet morphology of the fungus were assessed. The effect of different operational parameters (pH, glucose, and selenium concentration) on the response of P. chrysosporium to selenium oxyanions was explored as well. This fungal species showed a high sensitivity to selenium, particularly selenite, which inhibited the fungal growth and substrate consumption when supplied at 10 mg L(-1) in the growth medium, whereas selenate did not have such a strong influence on the fungus. Biological removal of selenite was achieved under semi-acidic conditions (pH 4.5) with about 40 % removal efficiency, whereas less than 10 % selenium removal was achieved for incubations with selenate. P. chrysosporium was found to be a selenium-reducing organism, capable of synthesizing elemental selenium from selenite but not from selenate. Analysis with transmission electron microscopy, electron energy loss spectroscopy, and a 3D reconstruction showed that elemental selenium was produced intracellularly as nanoparticles in the range of 30-400 nm. Furthermore, selenite influenced the pellet morphology of P. chrysosporium by reducing the size of the fungal pellets and inducing their compaction and smoothness.

Biodegradation of a mixture of PAHs by non-ligninolytic fungal strains isolated from crude oil-contaminated soil

Nine native non-ligninolytic fungal strains were isolated from Maya crude oil-contaminated soil and selected based on their ability to grow and use crude oil and several polycyclic aromatic hydrocarbons (PAHs) as carbon source, for their application to PAH removal in soil. The fungi were identified by PCR amplification of intergenic transcribed sequences regions and microbiological techniques, and results showed them to be part of the genera Fusarium, Neurospora, Aspergillus, Scedosporium, Penicillium, Neosartorya and Talaromyces. A primary selection of fungi was made in minimal medium plates, considering the tolerance to different concentrations of PAHs for each strain. The radial extension rate exhibited significant differences (p < 0.05) from 200 to 1,000 mg of PAHs mixture l⁻¹. A secondary selection of Aspergillus terreus, Talaromyces spectabilis, and Fusarium sp. was achieved based on their tolerance to 2,000 mg of a mixture of Phenanathrene and Pyrene kg⁻¹ of soil in a solid-state microcosm system for 2 weeks. The percentage of PAH removal obtained by the three strains was approximately 21 % of the mixture.

Performance of enhanced biological SBR process for aniline treatment by mycelial pellet as biomass carrier

Mycelial pellet of Aspergillus niger Y3 was used as a biomass carrier to immobilize the aniline-degrading bacterium, Acinetobacter calcoaceticus JH-9 and the mix culture of the COD rapid degradation bacteria. In order to investigate its removal effect on aniline and COD, the combined mycelial pellets were applied in the SBR. Comparison of the performances was conducted between another SBR inoculated with sole strain JH-9 and the above SBR. The results showed that the stable degradations of aniline and COD were observed in both reactors. In the SBR with combined mycelial pellet, the biological removal efficiency was about 0.9 mg aniline/(L·d). It was much higher than that in the activated sludge reactor. Meanwhile, the performances of the sedimentation velocity, liquid-solid phase separation and the effluent quality were better in the SBR. According to SEM images and PCR-DGGE analysis, the species immobilized on the biomass carrier were more predominant in this system.

Preliminary screening of co-substrates for bioremediation of pyrene-contaminated soil through composting

The feasibility of using different organic amendments of different origin and properties in the bioremediation of pyrene-contaminated soil by means of composting has been tested. The selected pyrene concentration was 1g of pyrene per kg of dry soil. The organic amendments used include: raw organic fraction of municipal solid wastes (OFMSW), industrial compost from OFMSW composting (COFMSW), compost derived from home composting of OFMSW (HCOFMSW), anaerobically digested sludge (ADS), non-digested activated sludge (NDS) and centrifuged non-digested activated sludge (CNDS). The degradation rate was related to the amendment properties that directly affected the composting process. Raw OFMSW was not capable to enhance pyrene degradation in comparison to control, but stable HCOFMSW exhibited the highest removal rate (69%). The amendments stability and the temperatures reached as a consequence influenced the process, and thermophilic temperatures showed an inhibition effect on the microbial activity related to pyrene degradation. Some of the tested wastes need to be further investigated to find inexpensive organic amendments for soil bioremediation.

Potential of Penicillium species in the bioremediation field

The effects on the environment of pollution, particularly that caused by various industrial activities, have been responsible for the accelerated fluxes of organic and inorganic matter in the ecosphere. Xenobiotics such as phenol, phenolic compounds, polycyclic aromatic hydrocarbons (PAHs), and heavy metals, even at low concentrations, can be toxic to humans and other forms of life. Many of the remediation technologies currently being used for contaminated soil and water involve not only physical and chemical treatment, but also biological processes, where microbial activity is the responsible for pollutant removal and/or recovery. Fungi are present in aquatic sediments, terrestrial habitats and water surfaces and play a significant part in natural remediation of metal and aromatic compounds. Fungi also have advantages over bacteria since fungal hyphae can penetrate contaminated soil, reaching not only heavy metals but also xenobiotic compounds. Despite of the abundance of such fungi in wastes, penicillia in particular have received little attention in bioremediation and biodegradation studies. Additionally, several studies conducted with different strains of imperfecti fungi, Penicillium spp. have demonstrated their ability to degrade different xenobiotic compounds with low co-substrate requirements, and could be potentially interesting for the development of economically feasible processes for pollutant transformation.

Interaction of higher plant (jute), electrofused bacteria and mycorrhiza on anthracene biodegradation

The interaction of bacteria, mycorrhiza and jute (Corchotus capsulari, a higher plant) to reduce anthracene in different concentrations of spiked soils was investigated. Dominant indigenous bacterium (Pseudomonas sp.) isolated in the rhizosphere of jute was electrofused with anthracene degraders (Sphingomonas paucimobilis and Pseudomonas aeruginosa) which were able to produce different types of biosurfactants. The highest population (56 x 10(5)CFU/g) was found in the planted soil with the inoculation of mixtures of electrofused anthracene degraders after 7 days. The growth of anthracene degraders in the spiked soil was improved by gene transfer from indigenous bacteria. After 35 days, enhanced anthracene removals were observed in inoculated soils planted with jute (65.5-75.2%) compared with unplanted soil without inoculation (12.5%). The interaction of jute and electrofused S. paucimobilis enabled the greatest reduction of soil anthracene with or without the addition of P. aeruginosa. Mycorrhizal colonization was not significantly inhibited by anthracene in soils up to 150 mg/kg. Inoculation of jute with Glomus mosseae and Glomus intraradices improved plant growth and enhanced anthracene removal in the presence of electrofused S. paucimobilis.