Microbial cells do not live in isolation in their environment, but rather they communicate with each other using chemical signals. This sophisticated mode of cell-to-cell signalling, known as quorum ...sensing, was first discovered in bacteria, and coordinates the behaviour of microbial population behaviour in a cell-density-dependent manner. More recently, these mechanisms have been described in eukaryotes, particularly in fungi, where they regulate processes such as pathogenesis, morphological differentiation, secondary metabolite production and biofilm formation. In this manuscript, we review the information available to date on these processes in yeast, dimorphic fungi and filamentous fungi. We analyse the diverse chemical 'languages' used by different groups of fungi, their possible cross-talk and interkingdom interactions with other organisms. We discuss the existence of these mechanisms in multicellular organisms, the ecophysiological role of QS in fungal colonisation and the potential applications of these mechanisms in biotechnology and pathogenesis.
Seafood has an important role to play to achieve a sustainable food system that provides healthy food to a growing world population. Future seafood production will be increasingly reliant on ...aquaculture where feed innovation is essential to reduce environmental impacts and minimize feed and food competition. This study aimed to investigate whether a novel single cell protein feed ingredient based on Paecilomyces variotii grown on a side stream from the forest industry could improve environmental sustainability of farmed rainbow trout (Oncorhynchus mykiss) by replacing the soy protein concentrate used today. A Life Cycle Assessment including commonly addressed impacts but also the rarely assessed biodiversity impacts was performed. Furthermore, feeding trials were included for potential effects on fish growth, i.e., an assessment of the environmental impacts for the functional unit 'kg feed required to produce 1 kg live-weight rainbow trout'. Results showed that the best experimental diet containing P. variotii performed 16-73 % better than the control diet containing soy protein concentrate in all impact categories except for energy demand (21 % higher impact). The largest environmental benefits from replacing soy protein with P. variotii in rainbow trout diets was a 73 % reduction of impact on biodiversity and halved greenhouse gas emissions. The findings have high relevance for the aquaculture industry as the production scale and feed composition was comparable to commercial operations and because the effect on fish growth from inclusion of the novel ingredient in a complete diet was evaluated. The results on biodiversity loss from land use change and exploitation through fishing suggest that fishery can dominate impacts and exclusion thereof can greatly underestimate biodiversity impact. Finally, a novel feed ingredient grown on side streams from the forest industry has potential to add to food security through decreasing the dependence on increasingly scarce agricultural land resources.
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•Interactome represents a whole set of interactions during lignocellulose breakdown.•Fungus-substrate interactome drives enzyme expression.•Enzyme-enzyme interactome involves ...synergism and LMW molecules exchanging.•Interactome can be driven to enhance biomass valorization.•Interactome can unlock the full potential of lignocellulosic components.
Biomass represents an abundant and inexpensive source of sugars and aromatic compounds that can be used as raw materials for conversion into value-added bioproducts. Filamentous fungi are sources of plant cell wall degrading enzymes in nature. Understanding the interactions between enzymes is crucial for optimizing biomass degradation processes. Herein, the concept of the interactome is presented as a holistic approach that depicts the interactions among enzymes, substrates, metabolites, and inhibitors. The interactome encompasses several stages of biomass degradation, starting with the sensing of the substrate and the subsequent synthesis of hydrolytic and oxidative enzymes (fungus-substrate interaction). Enzyme-enzyme interactions are exemplified in the complex processes of lignocellulosic biomass degradation. The enzyme-substrate-metabolite-inhibitor interaction also provides a better understanding of biomass conversion, allowing bioproduct production from recalcitrant agro-industrial residues, thus bringing greater value to residual biomass. Finally, technological applications are presented for optimizing the interactome at various levels.
Filamentous fungi play an important role in human health and industrial/agricultural production. With the increasing number of full genomes available for fungal species, the study of filamentous ...fungi has brought about a wider range of genetic manipulation opportunities. However, the utilization of traditional methods to study fungi is time consuming and laborious. Recent rapid progress and wide application of a versatile genome editing technology, i.e., the CRISPR (clustered regularly interspaced short palindromic repeat)–Cas9 (CRISPR-related nuclease 9) system, has revolutionized biological research and has many innovative applications in a wide range of fields showing great promise in research and application of filamentous fungi. In this review, we introduce the CRISPR/Cas9 genome editing technology focusing on its application in research of filamentous fungi and we discuss the general considerations of genome editing using CRISPR/Cas9 system illustrating vector construction, multiple editing strategies, technical consideration of different sizes of homology arms on genome editing efficiency, off-target effects, and different transformation methodologies. In addition, we discuss the challenges encountered using CRISPR/Cas9 technology and give the perspectives of future applications of CRISPR/Cas9 technology for basic research and practical application of filamentous fungi.
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•Filamentous fungi survived better than bacteria in HAGS under 250d refrigeration.•The gene copy ratio of fungi-to-bacteria increased from <1 to 185.5 during recovery.•Filamentous ...fungi dominate the system by utilizing EPS and organic matter.•The fungal genus unclassified_f_Nectriaceae caused the disintegration of HAGS.
Structural disintegration caused by the overgrowth of filamentous microorganisms is a major threat to the stable operation of aerobic granular sludge (AGS). In this study, the overgrowth of filamentous fungi was observed for the first time in halophilic aerobic granular sludge (HAGS) following reactivation after 250 days of refrigeration storage. The dominant filamentous fungi genera, with a relative abundance of 98.3 ± 0.2 %, were affiliated to the family Nectriaceae (unclassified_f_Nectriaceae). Originally existing in the HAGS nuclei, these filamentous fungi extended their hypha from the core to the surface of the HAGS during reactivation in the wastewater treatment system. The filamentous fungi could degrade extracellular polymeric substances produced by bacteria, as well as the organic matter in saline wastewater, under both anaerobic and aerobic conditions. These characteristics help the fungi maintain the growth advantage when bacteria in the HAGS were inhibited under the low temperature and anaerobic conditions. Under the aerobic condition, fungal growth was further promoted due to their broad carbon utilization and facultative respiration capacities, exerting a strong competitive advantage against halophilic bacteria, such as Marinobacterium, Halomonas and Vibrio. This study is the first to find and reveal the overgrowth of filamentous fungi in HAGS, providing a basis to regulate fungal growth and maintain the structural stability of HAGS.
Microalgae can provide a wide range of adsorption groups and have remarkable effects on pollutant removal owing to the presence of extracellular polymeric substances (EPS), with polysaccharides, ...polysaccharides, lipids, and nucleic acids as key components. However, the problem of high-cost harvesting of microalgae has become a bottleneck limiting their industrial application, due to microalgae due to their negatively charged cell surfaces in culture and their existence in suspended systems in their natural state. Because of their simple operation, safety and efficiency, filamentous fungi assist microalgae to forming symbiotic fungus-microalgae mycelium spheres as a new, green, and environmentally friendly microalgae harvesting technique. This review describes research progress on the construction conditions, symbiotic forces, and effectiveness of wastewater treatment using fungus-microalgae symbiotic systems. The factors influencing the construction of stable fungal-microalgal symbiotic mycelial spheres with efficient harvesting efficiency in culture (temperature, pH, carbon source, rotational speed, and light intensity), and the forces involved in the symbiotic process including electrostatic interactions, van der Waals forces, and EPS interaction, are briefly outlined. Symbiotic systems of fungi and algae in different industrial wastewaters have shown good treatment of chemical oxygen demand, total nitrogen, total phosphorous, and CO2. The current challenges and future prospects of the microalgae mycelium spheres are discussed. In addition, symbiotic mycelium spheres enhance the performance of wastewater treatment compared to microalgae or fungi system alone, which solves the difficult harvesting problem of microalgae and increases the feasibility of the system for practical industrial applications.
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•Symbiosis with filamentous fungi can achieve the purpose of microalgae harvesting.•The establishment of stable symbiosis system is related to various culture conditions.•The symbiosis between fungi and microalgae involves many forces.•Fungus-microalgae symbiotic system has a mutual and cooperative effect on pollutant removal.
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•Aspergillus nidulans successfully secreted high yields of recombinant AFUMN-GH10.•Biochemical and biophysical parameters of AFUMN-GH10 were elucidated.•The mode of action and ...biochemical properties were determined.•AFUMN-GH10 removed residual xylan from pre-treated lignocellulosic feedstock.
Xylanases decrease the xylan content in pretreated biomass releasing it from hemicellulose, thus improving the accessibility of cellulose for cellulases. In this work, an endo-β-1,4-xylanase from Aspergillus fumigatus var. niveus (AFUMN-GH10) was successfully expressed. The structural analysis and biochemical characterization showed this AFUMN-GH10 does not contain a carbohydrate-binding module. The enzyme retained its activity in a pH range from 4.5 to 7.0, with an optimal temperature at 60 °C. AFUMN-GH10 showed the highest activity in beechwood xylan. The mode of action of AFUMN-GH10 was investigated by hydrolysis of APTS-labeled xylohexaose, which resulted in xylotriose and xylobiose as the main products. AFUMN-GH10 released 27% of residual xylan from hydrothermally-pretreated corn stover and 14% of residual xylan from hydrothermally-pretreated sugarcane bagasse. The results showed that environmentally friendly pretreatment followed by enzymatic hydrolysis with AFUMN-GH10 in low concentration is a suitable method to remove part of residual and recalcitrant hemicellulose from biomass.
Biorefinery operations may be made more cost competitive through use of cheaper feedstocks (e.g. lignocellulosic wastes) and integration of multiple revenue streams. Current methods for converting ...lignocellulosics into valuable products are inefficient and expensive due to the complexity of the feedstock. By looking to nature, however, these expensive and complex processes may be consolidated into a simple, cheap, and environmentally benign process. The findings of this review demonstrate that the diversity of filamentous fungi is such that each step of the biorefining process may be catalyzed by a number of different species. While no single microorganism may catalyze all the process steps, by combining certain strains and targeting multiple products, the complete valorization of biomass may be achieved. This review describes in detail the variety of valuable chemical products that filamentous fungi produce, the variety of substrates used to produce these chemicals, and methods for maximizing production. The technical and economic findings herein demonstrate the means by which a successful integrated biorefinery model may be devised using filamentous fungi.
•Waste biomass is complex but may be completely valorized using filamentous fungi.•Biological methods for biomass conversion are environmentally advantageous.•Filamentous fungi convert biomass into a myriad of valuable products.•Filamentous fungi may enhance the economic viability of biomass operations.
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