Enabling community-based metrology for wood-degrading fungi

Raman Micro-spectroscopy and Imaging of Filamentous Fungi

Filamentous fungi grow by the elongation of tubular cells called hyphae and form mycelia through repeated hyphal tip growth and branching. Since hyphal growth is closely related to the ability to secrete large amounts of enzymes or invade host cells, a more detailed understanding and the control of its growth are important in fungal biotechnology, ecology, and pathogenesis. Previous studies using fluorescence imaging revealed many of the molecular mechanisms involved in hyphal growth. Raman microspectroscopy and imaging methods are now attracting increasing attention as powerful alternatives due to their high chemical specificity and label-free, non-destructive properties. Spatially resolved information on the relative abundance, structure, and chemical state of multiple intracellular components may be simultaneously obtained. Although Raman studies on filamentous fungi are still limited, this review introduces recent findings from Raman studies on filamentous fungi and discusses their potential use in the future.

Waste Rose Flower and Lavender Straw Biomass-An Innovative Lignocellulose Feedstock for Mycelium Bio-Materials Development Using Newly Isolated Ganoderma resinaceum GA1M

In this study, for the first time, the potential of rose flowers and lavender straw waste biomass was studied as feeding lignocellulose substrates for the cultivation of newly isolated in Bulgaria Ganoderma resinaceum GA1M with the objective of obtaining mycelium-based bio-composites. The chemical characterization and Fourier Transform Infrared (FTIR) spectroscopy established that the proximate composition of steam distilled lavender straw (SDLS) and hexane extracted rose flowers (HERF) was a serious prerequisite supporting the self-growth of mycelium bio-materials with improved antibacterial and aromatic properties. The basic physico-mechanical properties of the developed bio-composites were determined. The apparent density of the mycelium HERF-based bio-composites (462 kg/m³) was higher than that of the SDLS-based bio-composite (347 kg/m³) and both were much denser than expanded polystyren (EPS), lighter than medium-density fiber board (MDF) and oriented strand board (OSB) and similar to hempcrete. The preliminary testing of their compressive behavior revealed that the compressive resistance of SDLS-based bio-composite was 718 kPa, while for HERF-based bio-composite it was 1029 kPa and both values are similar to the compressive strength of hempcrete with similar apparent density. Water absorbance analysis showed, that both mycelium HERF- and SDLS-based bio-composites were hydrophilic and further investigations are needed to limit the hydrophilicity of the lignocellulose fibers, to tune the density and to improve compressive resistance.

Renewable mycelium based composite - sustainable approach for lignocellulose waste recovery and alternative to synthetic materials - a review

The agricultural waste with lignocellulose origin is considered to be one of the major environmental pollutants which, because of their high nutritional value, represent an extremely rich resource with significant potential for the production of value added bio-products. This review discusses the applications of higher fungi to upcycle abundant agricultural by-products into more sustainable materials and to promote the transition to a circular economy. It focuses on the main factors influencing the properties and application of mycelium composites - the feedstock, the basidiomycete species and their interaction with the feedstock. During controlled solid state cultivation on various lignocellulose substrates, the basidiomycetes of class Agaricomycetes colonize their surfaces and form a three-dimensional mycelium net. Fungal mycelium secretes enzymes that break down lignocellulose over time and are partially replaced by mycelium. The mycelium adheres to the residual undegraded substrates resulting in the formation of a high-mechanical-strength bio-material called a mycelium based bio-composite. The mycelium based bio-composites are completely natural, biodegradable and can be composted after their cycle of use is completed. The physicochemical, mechanical, and thermodynamic characteristics of mycelium based bio-composites are competitive with those of synthetic polymers and allow them to be successfully used in the construction, architecture, and other industries.

Trade-off between Plasticity and Velocity in Mycelial Growth

Tip-growing fungal cells maintain cell polarity at the apical regions and elongate by de novo synthesis of the cell wall. Cell polarity and tip growth rate affect mycelial morphology.

Tip-growing fungal cells maintain cell polarity at the apical regions and elongate by de novo synthesis of the cell wall. Cell polarity and tip growth rate affect mycelial morphology. However, it remains unclear how both features act cooperatively to determine cell shape. Here, we investigated this relationship by analyzing hyphal tip growth of filamentous fungi growing inside extremely narrow 1 μm-width channels of microfluidic devices. Since the channels are much narrower than the diameter of hyphae, any hypha growing through the channel must adapt its morphology. Live-cell imaging analyses revealed that hyphae of some species continued growing through the channels, whereas hyphae of other species often ceased growing when passing through the channels, or had lost apical polarity after emerging from the other end of the channel. Fluorescence live-cell imaging analyses of the Spitzenkörper, a collection of secretory vesicles and polarity-related proteins at the hyphal tip, in Neurospora crassa indicates that hyphal tip growth requires a very delicate balance of ordered exocytosis to maintain polarity in spatially confined environments. We analyzed the mycelial growth of seven fungal species from different lineages, including phytopathogenic fungi. This comparative approach revealed that the growth defects induced by the channels were not correlated with their taxonomic classification or with the width of hyphae, but, rather, correlated with the hyphal elongation rate. This report indicates a trade-off between morphological plasticity and velocity in mycelial growth and serves to help understand fungal invasive growth into substrates or plant/animal cells, with direct impact on fungal biotechnology, ecology, and pathogenicity.

Rapid and simultaneous screening of pathway designs and chassis organisms, applied to engineered living materials

Achieving a high product titer through pathway optimization often requires screening many combinations of enzymes and genetic parts. Typically, a library is screened in a single chassis that is a model or production organism. Here, we present a technique where the library is first introduced into B. subtilis XPORT, which has the ability to transfer the DNA to many Gram-positive species using an inducible integrated conjugated element (ICE). This approach is demonstrated using a two-gene pathway that converts tyrosine to melanin, a pigment biopolymer that can serve as a protective coating. A library of 18 pathway variants is conjugated by XPORT into 18 species, including those isolated from soil and industrial contaminants. The resulting 324 strains are screened and the highest titer is 1.2 g/L in B. amyloliquefaciens BT16. The strains were evaluated as co-cultures in an industrial process to make mycelia-grown bulk materials, where the bacteria need to be productive in a stressful, spatially non-uniform and dynamic environment. B. subtilis BGSC 3A35 is found to perform well under these conditions and make melanin in the material, which can be seen visually. This approach enables the simultaneous screening of genetic designs and chassis during the build step of metabolic engineering.

Growing a circular economy with fungal biotechnology: a white paper

Fungi have the ability to transform organic materials into a rich and diverse set of useful products and provide distinct opportunities for tackling the urgent challenges before all humans. Fungal biotechnology can advance the transition from our petroleum-based economy into a bio-based circular economy and has the ability to sustainably produce resilient sources of food, feed, chemicals, fuels, textiles, and materials for construction, automotive and transportation industries, for furniture and beyond. Fungal biotechnology offers solutions for securing, stabilizing and enhancing the food supply for a growing human population, while simultaneously lowering greenhouse gas emissions. Fungal biotechnology has, thus, the potential to make a significant contribution to climate change mitigation and meeting the United Nation’s sustainable development goals through the rational improvement of new and established fungal cell factories. The White Paper presented here is the result of the 2nd Think Tank meeting held by the EUROFUNG consortium in Berlin in October 2019. This paper highlights discussions on current opportunities and research challenges in fungal biotechnology and aims to inform scientists, educators, the general public, industrial stakeholders and policymakers about the current fungal biotech revolution.

From Hashtag to High School: How Viral Tweets Are Inspiring Young Scientists To Embrace STEM

Social media is an increasingly important professional tool for scientists. In particular, scientists use their social media profiles to communicate science and build communities with like-minded scientists and nonscientists. These networks include journalists who can amplify social media science communication, disseminating it to new audiences on- and offline. Our experience with an outreach project where Peeps marshmallows were inoculated with diverse fungi, which we called #FungalPeeps, has demonstrated that these networks can be an effective conduit between researchers and high school students. Following popular science journalism, #FungalPeeps, a project initiated at West Virginia University, inspired a mycology research project in Notre Dame High School in San Jose, California. Herein, we describe how this connection between academia, journalists, and the high school classroom happened, and how everyone involved benefited from this educational collaboration. We further suggest ways that modern social media networks could be leveraged to incorporate more such practical learning experiences into progressive science curricula to better cultivate young STEM scientists.