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Aiswarya N, Tabraiz S, Taneja H, Ahmed A, Aravinda Narayanan R. Nonlinear viscoelasticity of filamentous fungal biofilms of Neurospora discreta. Biofilm 2024; 8:100227. [PMID: 39430296 PMCID: PMC11490880 DOI: 10.1016/j.bioflm.2024.100227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2024] [Revised: 09/30/2024] [Accepted: 10/01/2024] [Indexed: 10/22/2024] Open
Abstract
The picture of bacterial biofilms as a colloidal gel composed of rigid bacterial cells protected by extracellular crosslinked polymer matrix has been pivotal in understanding their ability to adapt their microstructure and viscoelasticity to environmental assaults. This work explores if an analogous perspective exists in fungal biofilms with long filamentous cells. To this end, we consider biofilms of the fungus Neurospora discreta formed on the air-liquid interface, which has shown an ability to remove excess nitrogen and phosphorous from wastewater effectively. We investigated the changes to the viscoelasticity and the microstructure of these biofilms when the biofilms uptake varying concentrations of nitrogen and phosphorous, using large amplitude oscillatory shear flow rheology (LAOS) and field-emission scanning electron microscopy (FESEM), respectively. A distinctive peak in the loss modulus (G″) at 30-50 % shear strain is observed, indicating the transition from an elastic to plastic deformation state. Though a peak in G″ has been observed in several soft materials, including bacterial biofilms, it has eluded interpretation in terms of quantifiable microstructural features. The central finding of this work is that the intensity of the G″ peak, signifying resistance to large deformations, correlates directly with the protein and polysaccharide concentrations per unit biomass in the extracellular matrix and inversely with the shear-induced changes in filament orientation in the hyphal network. These correlations have implications for the rational design of fungal biofilms with tuneable mechanical properties.
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Affiliation(s)
- N.M. Aiswarya
- Department of Physics, Birla Institute of Technology and Science Pilani, Hyderabad Campus, India
| | - Shamas Tabraiz
- Section of Natural and Applied Sciences, Canterbury Christ Church University, UK
- Department of Civil and Environmental Engineering, Imperial College London, South Kensington Campus, Imperial College Road, SW7 2BU, London, UK
| | - Himani Taneja
- Section of Natural and Applied Sciences, Canterbury Christ Church University, UK
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA UK
| | - Asma Ahmed
- Section of Natural and Applied Sciences, Canterbury Christ Church University, UK
- Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham, Nottingham NG7 2RD, UK
| | - R. Aravinda Narayanan
- Department of Physics, Birla Institute of Technology and Science Pilani, Hyderabad Campus, India
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Tabraiz S, Aiswarya NM, Taneja H, Narayanan RA, Ahmed A. Biofilm-based simultaneous nitrification, denitrification, and phosphorous uptake in wastewater by Neurospora discreta. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 324:116363. [PMID: 36208511 DOI: 10.1016/j.jenvman.2022.116363] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 09/14/2022] [Accepted: 09/22/2022] [Indexed: 06/16/2023]
Abstract
Biological removal of nitrogen and phosphorous from wastewater conventionally involves multiple processing steps to satisfy the differing oxygen requirements of the microbial species involved. In this work, simultaneous nitrification, denitrification, and phosphorous removal from synthetic wastewater were achieved by the fungus Neurospora discreta in a single-step, biofilm-based, aerobic process. The concentrations of carbon, nitrogen, and phosphorous in the synthetic wastewater were systematically varied to investigate their effects on nutrient removal rates and biofilm properties. Biofilm growth was significantly (p < 0.05) affected by carbon and nitrogen, but not by phosphorous concentration. Scanning electron microscopy revealed the effects of nutrients on biofilm microstructure, which in turn correlated with nutrient removal efficiencies. The carbohydrate and protein content in the biofilm matrix decreased with increasing carbon and nitrogen concentrations but increased with increasing phosphorous concentration in the wastewater. High removal efficiencies of carbon (96%), ammonium (86%), nitrate (100%), and phosphorus (82%) were achieved under varying nutrient conditions. Interestingly, decreasing the phosphorus concentration increased the nitrification and denitrification rates, and decreasing the nitrogen concentration increased the phosphorus removal rates significantly (p < 0.05). Correlations between biofilm properties and nutrient removal rates were also evaluated in this study.
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Affiliation(s)
- Shamas Tabraiz
- Section of Natural and Applied Sciences, Canterbury Christ Church University, UK
| | - N M Aiswarya
- Department of Physics, Birla Institute of Technology and Science Pilani, Hyderabad Campus, India
| | - Himani Taneja
- Section of Natural and Applied Sciences, Canterbury Christ Church University, UK
| | - R Aravinda Narayanan
- Department of Physics, Birla Institute of Technology and Science Pilani, Hyderabad Campus, India
| | - Asma Ahmed
- Section of Natural and Applied Sciences, Canterbury Christ Church University, UK.
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Antinori ME, Contardi M, Suarato G, Armirotti A, Bertorelli R, Mancini G, Debellis D, Athanassiou A. Advanced mycelium materials as potential self-growing biomedical scaffolds. Sci Rep 2021; 11:12630. [PMID: 34135362 PMCID: PMC8209158 DOI: 10.1038/s41598-021-91572-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 05/17/2021] [Indexed: 12/11/2022] Open
Abstract
Mycelia, the vegetative part of fungi, are emerging as the avant-garde generation of natural, sustainable, and biodegradable materials for a wide range of applications. They are constituted of a self-growing and interconnected fibrous network of elongated cells, and their chemical and physical properties can be adjusted depending on the conditions of growth and the substrate they are fed upon. So far, only extracts and derivatives from mycelia have been evaluated and tested for biomedical applications. In this study, the entire fibrous structures of mycelia of the edible fungi Pleurotus ostreatus and Ganoderma lucidum are presented as self-growing bio-composites that mimic the extracellular matrix of human body tissues, ideal as tissue engineering bio-scaffolds. To this purpose, the two mycelial strains are inactivated by autoclaving after growth, and their morphology, cell wall chemical composition, and hydrodynamical and mechanical features are studied. Finally, their biocompatibility and direct interaction with primary human dermal fibroblasts are investigated. The findings demonstrate the potentiality of mycelia as all-natural and low-cost bio-scaffolds, alternative to the tissue engineering systems currently in place.
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Affiliation(s)
- Maria Elena Antinori
- Smart Materials, Fondazione Istituto Italiano Di Tecnologia, Via Morego 30, 16163, Genova, Italy
- DIBRIS, University of Genoa, Genoa, Italy
| | - Marco Contardi
- Smart Materials, Fondazione Istituto Italiano Di Tecnologia, Via Morego 30, 16163, Genova, Italy
| | - Giulia Suarato
- Smart Materials, Fondazione Istituto Italiano Di Tecnologia, Via Morego 30, 16163, Genova, Italy
- Translational Pharmacology, Fondazione Istituto Italiano Di Tecnologia, Via Morego 30, 16163, Genova, Italy
| | - Andrea Armirotti
- Analytical Chemistry Lab, Fondazione Istituto Italiano Di Tecnologia, Via Morego 30, 16163, Genova, Italy
| | - Rosalia Bertorelli
- Translational Pharmacology, Fondazione Istituto Italiano Di Tecnologia, Via Morego 30, 16163, Genova, Italy
| | - Giorgio Mancini
- Smart Materials, Fondazione Istituto Italiano Di Tecnologia, Via Morego 30, 16163, Genova, Italy
| | - Doriana Debellis
- Electron Microscopy Facility, Fondazione Istituto Italiano Di Tecnologia, Via Morego 30, 16163, Genova, Italy
| | - Athanassia Athanassiou
- Smart Materials, Fondazione Istituto Italiano Di Tecnologia, Via Morego 30, 16163, Genova, Italy.
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