1
|
van Kasteren S, Rozen DE. Using click chemistry to study microbial ecology and evolution. ISME COMMUNICATIONS 2023; 3:9. [PMID: 36721064 PMCID: PMC9889756 DOI: 10.1038/s43705-022-00205-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 11/16/2022] [Accepted: 11/23/2022] [Indexed: 02/01/2023]
Abstract
Technological advances have largely driven the revolution in our understanding of the structure and function of microbial communities. Culturing, long the primary tool to probe microbial life, was supplanted by sequencing and other -omics approaches, which allowed detailed quantitative insights into species composition, metabolic potential, transcriptional activity, secretory responses and more. Although the ability to characterize "who's there" has never been easier or cheaper, it remains technically challenging and expensive to understand what the diverse species and strains that comprise microbial communities are doing in situ, and how these behaviors change through time. Our aim in this brief review is to introduce a developing toolkit based on click chemistry that can accelerate and reduce the expense of functional analyses of the ecology and evolution of microbial communities. After first outlining the history of technological development in this field, we will discuss key applications to date using diverse labels, including BONCAT, and then end with a selective (biased) view of areas where click-chemistry and BONCAT-based approaches stand to have a significant impact on our understanding of microbial communities.
Collapse
Affiliation(s)
- Sander van Kasteren
- Leiden Institute of Chemistry and The Institute of Chemical Immunology, Leiden University, Einsteinweg 55, Leiden, 2300 RA, The Netherlands.
| | - Daniel E Rozen
- Institute of Biology, Leiden University, Sylviusweg 72, Leiden, 2300 RA, The Netherlands.
| |
Collapse
|
2
|
Heterogeneous Distribution of Phospholipid Molecular Species in the Surface Culture of Flammulina velutipes: New Facts about Lipids Containing α-Linolenic Fatty Acid. J Fungi (Basel) 2023; 9:jof9010102. [PMID: 36675923 PMCID: PMC9865325 DOI: 10.3390/jof9010102] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 01/08/2023] [Accepted: 01/09/2023] [Indexed: 01/15/2023] Open
Abstract
Mycelial fungi grow as colonies consisting of polar growing hyphae, developing radially from spore or inoculum. Over time, the colony develops, hyphae are subject to various exogenous or endogenous stimuli, and mycelium becomes heterogeneous in growth, gene expression, biosynthesis, and secretion of proteins and metabolites. Although the biochemical and molecular mechanisms of mycelium heterogeneity have been the subject of many studies, the role of lipids in colony development and zonality is still not understood. This work was undertaken to extend our knowledge of mycelium heterogeneity and to answer the question of how different lipid molecular species are distributed in the surface colony of the basidial fungus Flammulina velutipes and how this distribution correlates with its morphology. The heterogeneity in the lipid metabolism and lipid composition of the fungal mycelium was demonstrated. According to the real-time PCR and LC-MS/MS results, the expression of genes of PC metabolism, accumulation of phospholipid classes, and degree of unsaturation of PC and PE increased in the direction from the center to the periphery of the colony. The peripheral zone of the colony was characterized by a higher value of the PC/PE ratio and a higher level of phospholipids esterified by linolenic acid. Considering that the synthesis of phospholipids in fungi occurs in different ways, we also conducted experiments with deuterium-labeled phospholipid precursors and found out that the Kennedy pathway is the predominant route for PC biosynthesis in F. velutipes. The zonal differences in gene expression and lipid composition can be explained by the participation of membrane lipids in polar growth maintenance and regulation.
Collapse
|
3
|
Palacio‐Barrera AM, Schlembach I, Finger M, Büchs J, Rosenbaum MA. Reliable online measurement of population dynamics for filamentous co-cultures. Microb Biotechnol 2022; 15:2773-2785. [PMID: 35972427 PMCID: PMC9618322 DOI: 10.1111/1751-7915.14129] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 07/28/2022] [Indexed: 11/30/2022] Open
Abstract
Understanding population dynamics is a key factor for optimizing co-culture processes to produce valuable compounds. However, the measurement of independent population dynamics is difficult, especially for filamentous organisms and in presence of insoluble substrates like cellulose. We propose a workflow for fluorescence-based online monitoring of individual population dynamics of two filamentous microorganisms. The fluorescent tagged target co-culture is composed of the cellulolytic fungus Trichoderma reesei RUT-C30-mCherry and the pigment-producing bacterium Streptomyces coelicolor A3(2)-mNeonGreen (mNG) growing on insoluble cellulose as a substrate. To validate the system, the fluorescence-to-biomass and fluorescence-to-scattered-light correlation of the two strains was characterized in depth under various conditions. Thereby, especially for complex filamentous microorganisms, microbial morphologies have to be considered. Another bias can arise from autofluorescence or pigments that can spectrally interfere with the fluorescence measurement. Green autofluorescence of both strains was uncoupled from different green fluorescent protein signals through a spectral unmixing approach, resulting in a specific signal only linked to the abundance of S. coelicolor A3(2)-mNG. As proof of principle, the population dynamics of the target co-culture were measured at varying inoculation ratios in presence of insoluble cellulose particles. Thereby, the respective fluorescence signals reliably described the abundance of each partner, according to the variations in the inocula. With this method, conditions can be fine-tuned for optimal growth of both partners along with natural product formation by the bacterium.
Collapse
Affiliation(s)
- Ana M. Palacio‐Barrera
- Leibniz Institute for Natural Product Research and Infection BiologyHans‐Knöll‐InstituteJenaGermany
- Faculty of Biological SciencesFriedrich‐Schiller‐University JenaJenaGermany
| | - Ivan Schlembach
- Leibniz Institute for Natural Product Research and Infection BiologyHans‐Knöll‐InstituteJenaGermany
- Faculty of Biological SciencesFriedrich‐Schiller‐University JenaJenaGermany
| | - Maurice Finger
- RWTH Aachen UniversityAVT—Biochemical EngineeringAachenGermany
| | - Jochen Büchs
- RWTH Aachen UniversityAVT—Biochemical EngineeringAachenGermany
| | - Miriam A. Rosenbaum
- Leibniz Institute for Natural Product Research and Infection BiologyHans‐Knöll‐InstituteJenaGermany
- Faculty of Biological SciencesFriedrich‐Schiller‐University JenaJenaGermany
| |
Collapse
|
4
|
Bartholomai BM, Gladfelter AS, Loros JJ, Dunlap JC. PRD-2 mediates clock-regulated perinuclear localization of clock gene RNAs within the circadian cycle of Neurospora. Proc Natl Acad Sci U S A 2022; 119:e2203078119. [PMID: 35881801 PMCID: PMC9351534 DOI: 10.1073/pnas.2203078119] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Accepted: 06/24/2022] [Indexed: 02/02/2023] Open
Abstract
The transcription-translation negative feedback loops underlying animal and fungal circadian clocks are remarkably similar in their molecular regulatory architecture and, although much is understood about their central mechanism, little is known about the spatiotemporal dynamics of the gene products involved. A common feature of these circadian oscillators is a significant temporal delay between rhythmic accumulation of clock messenger RNAs (mRNAs) encoding negative arm proteins, for example, frq in Neurospora and Per1-3 in mammals, and the appearance of the clock protein complexes assembled from the proteins they encode. Here, we report use of single-molecule RNA fluorescence in situ hybridization (smFISH) to show that the fraction of nuclei actively transcribing the clock gene frq changes in a circadian manner, and that these mRNAs cycle in abundance with fewer than five transcripts per nucleus at any time. Spatial point patterning statistics reveal that frq is spatially clustered near nuclei in a time of day-dependent manner and that clustering requires an RNA-binding protein, PRD-2 (PERIOD-2), recently shown also to bind to mRNA encoding another core clock component, casein kinase 1. An intrinsically disordered protein, PRD-2 displays behavior in vivo and in vitro consistent with participation in biomolecular condensates. These data are consistent with a role for phase-separating RNA-binding proteins in spatiotemporally organizing clock mRNAs to facilitate local translation and assembly of clock protein complexes.
Collapse
Affiliation(s)
- Bradley M. Bartholomai
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
| | - Amy S. Gladfelter
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Jennifer J. Loros
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
| | - Jay C. Dunlap
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
| |
Collapse
|
5
|
Abstract
Anoxic microsites arising in fungal biofilms may foster the presence of obligate anaerobes. Here, we analyzed whether and to which degree hyphae of Coprinopsis cinerea thriving in oxic habitats enable the germination, growth, and dispersal of the obligate anaerobic soil bacterium Clostridium acetobutylicum. Time-resolved optical oxygen mapping, microscopy, and metabolite analysis revealed the formation and persistence of anoxic circum hyphal niches, allowing for spore germination, growth, and fermentative activity of the obligate anaerobe in an otherwise inhabitable environment. Hypoxic liquid films containing 80% ± 10% of atmospheric oxygen saturation around single air-exposed hyphae thereby allowed for efficient clostridial dispersal amid spatially separated (>0.5 cm) anoxic sites. Hyphae hence may serve as good networks for the activity and spatial organization of obligate anaerobic bacteria in oxygenated heterogeneous environments such as soil.
Collapse
|
6
|
Xiong BJ, Stanley CE, Dusny C, Schlosser D, Harms H, Wick LY. pH Distribution along Growing Fungal Hyphae at Microscale. J Fungi (Basel) 2022; 8:599. [PMID: 35736082 PMCID: PMC9224906 DOI: 10.3390/jof8060599] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 05/30/2022] [Accepted: 05/31/2022] [Indexed: 02/06/2023] Open
Abstract
Creating unique microenvironments, hyphal surfaces and their surroundings allow for spatially distinct microbial interactions and functions at the microscale. Using a microfluidic system and pH-sensitive whole-cell bioreporters (Synechocystis sp. PCC6803) attached to hyphae, we spatially resolved the pH along surfaces of growing hyphae of the basidiomycete Coprinopsis cinerea. Time-lapse microscopy analysis of ratiometric fluorescence signals of >2400 individual bioreporters revealed an overall pH drop from 6.3 ± 0.4 (n = 2441) to 5.0 ± 0.3 (n = 2497) within 7 h after pH bioreporter loading to hyphal surfaces. The pH along hyphal surfaces varied significantly (p < 0.05), with pH at hyphal tips being on average ~0.8 pH units lower than at more mature hyphal parts near the entrance of the microfluidic observation chamber. Our data represent the first dynamic in vitro analysis of surface pH along growing hyphae at the micrometre scale. Such knowledge may improve our understanding of spatial, pH-dependent hyphal processes, such as the degradation of organic matter or mineral weathering.
Collapse
Affiliation(s)
- Bi-Jing Xiong
- Helmholtz Centre for Environmental Research-UFZ, Department of Environmental Microbiology, Permoserstraβe 15, 04318 Leipzig, Germany; (B.-J.X.); (D.S.); (H.H.)
| | - Claire E. Stanley
- Department of Bioengineering, Imperial College of London, South Kensington Campus, London SW7 2AZ, UK;
| | - Christian Dusny
- Helmholtz Centre for Environmental Research-UFZ, Department of Solar Materials, Permoserstraβe 15, 04318 Leipzig, Germany;
| | - Dietmar Schlosser
- Helmholtz Centre for Environmental Research-UFZ, Department of Environmental Microbiology, Permoserstraβe 15, 04318 Leipzig, Germany; (B.-J.X.); (D.S.); (H.H.)
| | - Hauke Harms
- Helmholtz Centre for Environmental Research-UFZ, Department of Environmental Microbiology, Permoserstraβe 15, 04318 Leipzig, Germany; (B.-J.X.); (D.S.); (H.H.)
| | - Lukas Y. Wick
- Helmholtz Centre for Environmental Research-UFZ, Department of Environmental Microbiology, Permoserstraβe 15, 04318 Leipzig, Germany; (B.-J.X.); (D.S.); (H.H.)
| |
Collapse
|
7
|
Morales DP, Robinson AJ, Pawlowski AC, Ark C, Kelliher JM, Junier P, Werner JH, Chain PSG. Advances and Challenges in Fluorescence in situ Hybridization for Visualizing Fungal Endobacteria. Front Microbiol 2022; 13:892227. [PMID: 35722318 PMCID: PMC9199388 DOI: 10.3389/fmicb.2022.892227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 05/04/2022] [Indexed: 11/18/2022] Open
Abstract
Several bacteria have long been known to interact intimately with fungi, but molecular approaches have only recently uncovered how cosmopolitan these interactions are in nature. Currently, bacterial–fungal interactions (BFI) are inferred based on patterns of co-occurrence in amplicon sequencing investigations. However, determining the nature of these interactions, whether the bacteria are internally or externally associated, remains a grand challenge in BFI research. Fluorescence in situ hybridization (FISH) is a robust method that targets unique sequences of interest which can be employed for visualizing intra-hyphal targets, such as mitochondrial organelles or, as in this study, bacteria. We evaluate the challenges and employable strategies to resolve intra-hyphal BFI to address pertinent criteria in BFI research, such as culturing media, spatial distribution of bacteria, and abundance of bacterial 16S rRNA copies for fluorescent labeling. While these experimental factors influence labeling and detection of endobacteria, we demonstrate how to overcome these challenges thorough permeabilization, appropriate media choice, and targeted amplification using hybridization chain reaction FISH. Such microscopy imaging approaches can now be utilized by the broader research community to complement sequence-based investigations and provide more conclusive evidence on the nature of specific bacterial–fungal relationships.
Collapse
Affiliation(s)
- Demosthenes P. Morales
- Center of Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM, United States
- *Correspondence: Demosthenes P. Morales,
| | - Aaron J. Robinson
- Biosecurity and Public Health, Los Alamos National Laboratory, Los Alamos, NM, United States
| | - Andrew C. Pawlowski
- Department of Genetics, Harvard Medical School, Boston, MA, United States
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, United States
| | - Caitlyn Ark
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, United States
| | - Julia M. Kelliher
- Biosecurity and Public Health, Los Alamos National Laboratory, Los Alamos, NM, United States
| | - Pilar Junier
- Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - James H. Werner
- Center of Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM, United States
| | - Patrick S. G. Chain
- Biosecurity and Public Health, Los Alamos National Laboratory, Los Alamos, NM, United States
| |
Collapse
|
8
|
Bartholomai BM, Gladfelter AS, Loros JJ, Dunlap JC. Quantitative single molecule RNA-FISH and RNase-free cell wall digestion in Neurospora crassa. Fungal Genet Biol 2021; 156:103615. [PMID: 34425213 PMCID: PMC8463489 DOI: 10.1016/j.fgb.2021.103615] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 08/13/2021] [Accepted: 08/15/2021] [Indexed: 10/20/2022]
Abstract
Single molecule RNA-FISH (smFISH) is a valuable tool for analysis of mRNA spatial patterning in fixed cells that is underutilized in filamentous fungi. A primary complication for fixed-cell imaging in filamentous fungi is the need for enzymatic cell wall permeabilization, which is compounded by considerable variability in cell wall composition between species. smFISH adds another layer of complexity due to a requirement for RNase free conditions. Here, we describe the cloning, expression, and purification of a chitinase suitable for supplementation of a commercially available RNase-free enzyme preparation for efficient permeabilization of the Neurospora cell wall. We further provide a method for smFISH in Neurospora which includes a tool for generating numerical data from images that can be used in downstream customized analysis protocols.
Collapse
Affiliation(s)
- Bradley M Bartholomai
- Geisel School of Medicine at Dartmouth, Department of Molecular and Systems Biology, Hanover, NH, USA
| | - Amy S Gladfelter
- University of North Carolina, Department of Biology, Chapel Hill, NC, USA
| | - Jennifer J Loros
- Geisel School of Medicine at Dartmouth, Department of Biochemistry and Cell Biology, Hanover, NH, USA
| | - Jay C Dunlap
- Geisel School of Medicine at Dartmouth, Department of Molecular and Systems Biology, Hanover, NH, USA.
| |
Collapse
|
9
|
Böl M, Schrinner K, Tesche S, Krull R. Challenges of influencing cellular morphology by morphology engineering techniques and mechanical induced stress on filamentous pellet systems-A critical review. Eng Life Sci 2021; 21:51-67. [PMID: 33716605 PMCID: PMC7923580 DOI: 10.1002/elsc.202000060] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 09/25/2020] [Accepted: 09/29/2020] [Indexed: 11/30/2022] Open
Abstract
Filamentous microorganisms are main producers of organic acids, enzymes, and pharmaceutical agents such as antibiotics and other active pharmaceutical ingredients. With their complex cell morphology, ranging from dispersed mycelia to dense pellets, the cultivation is challenging. In recent years, various techniques for tailor-made cell morphologies of filamentous microorganisms have been developed to increase product formation and have been summarised under the term morphology engineering. These techniques, namely microparticle-enhanced cultivation, macroparticle-enhanced cultivation, and alteration of the osmolality of the culture medium by addition of inorganic salts, the salt-enhanced cultivation, are presented and discussed in this review. These techniques have already proven to be useful and now await further proof-of-concept. Furthermore, the mechanical behaviour of individual pellets is of special interest for a general understanding of pellet mechanics and the productivity of biotechnological processes with filamentous microorganisms. Correlating them with substrate uptake and finally with productivity would be a breakthrough not to be underestimated for the comprehensive characterisation of filamentous systems. So far, this research field is under-represented. First results on filamentous pellet mechanics are discussed and important future aspects, which the filamentous expert community should deal with, will be presented and critically discussed.
Collapse
Affiliation(s)
- Markus Böl
- Institute of Mechanics and AdaptronicsTechnische Universität BraunschweigBraunschweigGermany
- Center of Pharmaceutical Engineering (PVZ)Technische Universität BraunschweigBraunschweigGermany
| | - Kathrin Schrinner
- Center of Pharmaceutical Engineering (PVZ)Technische Universität BraunschweigBraunschweigGermany
- Institute of Biochemical EngineeringTechnische Universität BraunschweigBraunschweigGermany
| | - Sebastian Tesche
- Center of Pharmaceutical Engineering (PVZ)Technische Universität BraunschweigBraunschweigGermany
- Institute of Biochemical EngineeringTechnische Universität BraunschweigBraunschweigGermany
| | - Rainer Krull
- Center of Pharmaceutical Engineering (PVZ)Technische Universität BraunschweigBraunschweigGermany
- Institute of Biochemical EngineeringTechnische Universität BraunschweigBraunschweigGermany
| |
Collapse
|
10
|
Tesche S, Krull R. An image analysis method to quantify heterogeneous filamentous biomass based on pixel intensity values – Interrelation of macro- and micro-morphology in Actinomadura namibiensis. Biochem Eng J 2021. [DOI: 10.1016/j.bej.2020.107865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
11
|
Schmideder S, Müller H, Barthel L, Friedrich T, Niessen L, Meyer V, Briesen H. Universal law for diffusive mass transport through mycelial networks. Biotechnol Bioeng 2020; 118:930-943. [PMID: 33169831 DOI: 10.1002/bit.27622] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 10/13/2020] [Accepted: 10/31/2020] [Indexed: 01/01/2023]
Abstract
Filamentous fungal cell factories play a pivotal role in biotechnology and circular economy. Hyphal growth and macroscopic morphology are critical for product titers; however, these are difficult to control and predict. Usually pellets, which are dense networks of branched hyphae, are formed during industrial cultivations. They are nutrient- and oxygen-depleted in their core due to limited diffusive mass transport, which compromises productivity of bioprocesses. Here, we demonstrate that a generalized law for diffusive mass transport exists for filamentous fungal pellets. Diffusion computations were conducted based on three-dimensional X-ray microtomography measurements of 66 pellets originating from four industrially exploited filamentous fungi and based on 3125 Monte Carlo simulated pellets. Our data show that the diffusion hindrance factor follows a scaling law with respect to the solid hyphal fraction. This law can be harnessed to predict diffusion of nutrients, oxygen, and secreted metabolites in any filamentous pellets and will thus advance the rational design of pellet morphologies on genetic and process levels.
Collapse
Affiliation(s)
- Stefan Schmideder
- School of Life Sciences Weihenstephan, Chair of Process Systems Engineering, Technical University of Munich, Freising, Germany
| | - Henri Müller
- School of Life Sciences Weihenstephan, Chair of Process Systems Engineering, Technical University of Munich, Freising, Germany
| | - Lars Barthel
- Institute of Biotechnology, Faculty III Process Sciences, Chair of Applied and Molecular Microbiology, Technische Universität Berlin, Berlin, Germany
| | - Tiaan Friedrich
- School of Life Sciences Weihenstephan, Chair of Process Systems Engineering, Technical University of Munich, Freising, Germany
| | - Ludwig Niessen
- School of Life Sciences Weihenstephan, Chair of Technical Microbiology, Technical University of Munich, Freising, Germany
| | - Vera Meyer
- Institute of Biotechnology, Faculty III Process Sciences, Chair of Applied and Molecular Microbiology, Technische Universität Berlin, Berlin, Germany
| | - Heiko Briesen
- School of Life Sciences Weihenstephan, Chair of Process Systems Engineering, Technical University of Munich, Freising, Germany
| |
Collapse
|
12
|
Mela AP, Rico-Ramírez AM, Glass NL. Syncytia in Fungi. Cells 2020; 9:cells9102255. [PMID: 33050028 PMCID: PMC7600787 DOI: 10.3390/cells9102255] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 09/27/2020] [Accepted: 09/29/2020] [Indexed: 12/27/2022] Open
Abstract
Filamentous fungi typically grow as interconnected multinucleate syncytia that can be microscopic to many hectares in size. Mechanistic details and rules that govern the formation and function of these multinucleate syncytia are largely unexplored, including details on syncytial morphology and the regulatory controls of cellular and molecular processes. Recent discoveries have revealed various adaptations that enable fungal syncytia to accomplish coordinated behaviors, including cell growth, nuclear division, secretion, communication, and adaptation of the hyphal network for mixing nuclear and cytoplasmic organelles. In this review, we highlight recent studies using advanced technologies to define rules that govern organizing principles of hyphal and colony differentiation, including various aspects of nuclear and mitochondrial cooperation versus competition. We place these findings into context with previous foundational literature and present still unanswered questions on mechanistic aspects, function, and morphological diversity of fungal syncytia across the fungal kingdom.
Collapse
Affiliation(s)
- Alexander P. Mela
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA; (A.P.M.); (A.M.R.-R.)
| | - Adriana M. Rico-Ramírez
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA; (A.P.M.); (A.M.R.-R.)
| | - N. Louise Glass
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA; (A.P.M.); (A.M.R.-R.)
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Correspondence:
| |
Collapse
|
13
|
Schrinner K, Veiter L, Schmideder S, Doppler P, Schrader M, Münch N, Althof K, Kwade A, Briesen H, Herwig C, Krull R. Morphological and physiological characterization of filamentous Lentzea aerocolonigenes: Comparison of biopellets by microscopy and flow cytometry. PLoS One 2020; 15:e0234125. [PMID: 32492063 PMCID: PMC7269266 DOI: 10.1371/journal.pone.0234125] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 05/19/2020] [Indexed: 12/27/2022] Open
Abstract
Cell morphology of filamentous microorganisms is highly interesting during cultivations as it is often linked to productivity and can be influenced by process conditions. Hence, the characterization of cell morphology is of major importance to improve the understanding of industrial processes with filamentous microorganisms. For this purpose, reliable and robust methods are necessary. In this study, pellet morphology and physiology of the rebeccamycin producing filamentous actinomycete Lentzea aerocolonigenes were investigated by microscopy and flow cytometry. Both methods were compared regarding their applicability. To achieve different morphologies, a cultivation with glass bead addition (Ø = 969 μm, 100 g L-1) was compared to an unsupplemented cultivation. This led to two different macro-morphologies. Furthermore, glass bead addition increased rebeccamycin titers after 10 days of cultivation (95 mg L-1 with glass beads, 38 mg L-1 without glass beads). Macro-morphology and viability were investigated through microscopy and flow cytometry. For viability assessment fluorescent staining was used additionally. Smaller, more regular pellets were found for glass bead addition. Pellet diameters resulting from microscopy followed by image analysis were 172 μm without and 106 μm with glass beads, diameters from flow cytometry were 170 and 100 μm, respectively. These results show excellent agreement of both methods, each considering several thousand pellets. Furthermore, the pellet viability obtained from both methods suggested an enhanced metabolic activity in glass bead treated pellets during the exponential production phase. However, total viability values differ for flow cytometry (0.32 without and 0.41 with glass beads) and confocal laser scanning microscopy of single stained pellet slices (life ratio in production phase of 0.10 without and 0.22 with glass beads), which is probably caused by the different numbers of investigated pellets. In confocal laser scanning microscopy only one pellet per sample could be investigated while flow cytometry considered at least 50 pellets per sample, resulting in an increased statistical reliability.
Collapse
Affiliation(s)
- Kathrin Schrinner
- Institute of Biochemical Engineering, Technische Universität Braunschweig, Braunschweig, Germany
- Technische Universität Braunschweig, Center of Pharmaceutical Engineering, Braunschweig, Germany
| | - Lukas Veiter
- Institute of Chemical, Environmental and Bioscience Engineering, Research Area Biochemical Engineering, Technische Universität Wien, Vienna, Austria
- Competence Center CHASE GmbH, Linz, Austria
| | - Stefan Schmideder
- School of Life Sciences, Chair of Process Systems Engineering, Technische Universität München, Freising, Germany
| | - Philipp Doppler
- Institute of Chemical, Environmental and Bioscience Engineering, Research Area Biochemical Engineering, Technische Universität Wien, Vienna, Austria
| | - Marcel Schrader
- Technische Universität Braunschweig, Center of Pharmaceutical Engineering, Braunschweig, Germany
- Institute for Particle Technology, Technische Universität Braunschweig, Braunschweig, Germany
| | - Nadine Münch
- School of Life Sciences, Chair of Process Systems Engineering, Technische Universität München, Freising, Germany
| | - Kristin Althof
- Institute of Biochemical Engineering, Technische Universität Braunschweig, Braunschweig, Germany
| | - Arno Kwade
- Technische Universität Braunschweig, Center of Pharmaceutical Engineering, Braunschweig, Germany
- Institute for Particle Technology, Technische Universität Braunschweig, Braunschweig, Germany
| | - Heiko Briesen
- School of Life Sciences, Chair of Process Systems Engineering, Technische Universität München, Freising, Germany
| | - Christoph Herwig
- Institute of Chemical, Environmental and Bioscience Engineering, Research Area Biochemical Engineering, Technische Universität Wien, Vienna, Austria
| | - Rainer Krull
- Institute of Biochemical Engineering, Technische Universität Braunschweig, Braunschweig, Germany
- Technische Universität Braunschweig, Center of Pharmaceutical Engineering, Braunschweig, Germany
| |
Collapse
|
14
|
Biofilm Mode of Cultivation Leads to an Improvement of the Entomotoxic Patterns of Two Aspergillus Species. Microorganisms 2020; 8:microorganisms8050705. [PMID: 32403244 PMCID: PMC7284871 DOI: 10.3390/microorganisms8050705] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 05/02/2020] [Accepted: 05/07/2020] [Indexed: 12/29/2022] Open
Abstract
Two fungi, i.e., Aspergillus flavus Link and Aspergillus oryzae (Ahlb.) E. Cohn, were cultivated according to two methodologies, namely submerged and biofilm cultures with the primary aim to use their secondary metabolites the supernatant CL50, and CL90 varied between 1.3% (v/v) to 12.7% (v/v) for incubation times from 24 to 72 h. While the A. flavus supernatant entomotoxicity was higher than this of A. oryzae, the biofilm culture application increased the efficiency of the former. Proteomic analysis of the supernatants revealed discrepancies among the two species and modes of cultivation. Furthermore, the secondary metabolite profiles of both Aspergillus cultures were verified. Aspergillic acid, beta-cyclopiazonic acid, cyclopiazonic acid, ferrineospergillin, flavacol, and spermadin A were most predominant. Generally, these secondary metabolites were present in higher concentrations in the supernatants of A. flavus and biofilm cultures. These molecular identifications correlated positively with entomotoxic activity. Noteworthy, the absence of carcinogenic aflatoxins was remarkable, and it will allow further valorization to produce A. flavus to develop potential biopesticides.
Collapse
|
15
|
Division of labor and growth during electrical cooperation in multicellular cable bacteria. Proc Natl Acad Sci U S A 2020; 117:5478-5485. [PMID: 32094191 PMCID: PMC7071850 DOI: 10.1073/pnas.1916244117] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cable bacteria form centimeter-long, multicellular filaments whose energy metabolism involves cooperation among cells that separately perform oxidation of the electron donor and reduction of the electron acceptor. This cooperative division of labor is facilitated via long-range electrical currents that run from cell to cell along a network of conductive fibers. Here we show that biomass synthesis shows a surprising asymmetry along the filament: only the cells oxidizing the electron donor conserve energy for growth, while the other cells reduce electron acceptors without biosynthesis. Our study hence provides insights into the physiology of an unconventional chemolithotroph, which forms a multicellular electrically connected system with unique functional differentiation, integration, and coordination. Multicellularity is a key evolutionary innovation, leading to coordinated activity and resource sharing among cells, which generally occurs via the physical exchange of chemical compounds. However, filamentous cable bacteria display a unique metabolism in which redox transformations in distant cells are coupled via long-distance electron transport rather than an exchange of chemicals. This challenges our understanding of organismal functioning, as the link among electron transfer, metabolism, energy conservation, and filament growth in cable bacteria remains enigmatic. Here, we show that cells within individual filaments of cable bacteria display a remarkable dichotomy in biosynthesis that coincides with redox zonation. Nanoscale secondary ion mass spectrometry combined with 13C (bicarbonate and propionate) and 15N-ammonia isotope labeling reveals that cells performing sulfide oxidation in deeper anoxic horizons have a high assimilation rate, whereas cells performing oxygen reduction in the oxic zone show very little or no label uptake. Accordingly, oxygen reduction appears to merely function as a mechanism to quickly dispense of electrons with little to no energy conservation, while biosynthesis and growth are restricted to sulfide-respiring cells. Still, cells can immediately switch roles when redox conditions change, and show no differentiation, which suggests that the “community service” performed by the cells in the oxic zone is only temporary. Overall, our data reveal a division of labor and electrical cooperation among cells that has not been seen previously in multicellular organisms.
Collapse
|
16
|
Tegelaar M, Bleichrodt RJ, Nitsche B, Ram AFJ, Wösten HAB. Subpopulations of hyphae secrete proteins or resist heat stress in Aspergillus oryzae colonies. Environ Microbiol 2019; 22:447-455. [PMID: 31736205 PMCID: PMC6972715 DOI: 10.1111/1462-2920.14863] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 10/17/2019] [Accepted: 11/14/2019] [Indexed: 01/19/2023]
Abstract
Hyphae at the outer part of colonies of Aspergillus niger and Aspergillus oryzae are heterogeneous with respect to transcriptional and translational activity. This heterogeneity is maintained by Woronin body mediated closure of septal pores that block interhyphal mixing of cytoplasm. Indeed, heterogeneity between hyphae is abolished in ΔhexA strains that lack Woronin bodies. The subpopulation of hyphae with high transcriptional and translational activity secretes enzymes that degrade the substrate resulting in breakdown products that serve as nutrients. The role of hyphae with low transcriptional and translational activity was not yet known. Here, we show that this subpopulation is more resistant to environmental stress in A. oryzae, in particular to temperature stress, when compared to hyphae with high transcriptional and translational activity. Notably, all hyphae of the ΔhexA strain of A. oryzae were sensitive to heat stress explained by the reduced heterogeneity in this strain. Together, we show that different subpopulations of hypha secrete proteins and resist heat stress showing the complexity of a fungal mycelium.
Collapse
Affiliation(s)
- Martin Tegelaar
- Microbiology, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | | | - Benjamin Nitsche
- Molecular Microbiology and Biotechnology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
| | - Arthur F J Ram
- Molecular Microbiology and Biotechnology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
| | - Han A B Wösten
- Microbiology, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| |
Collapse
|
17
|
Filamentous fungi for the production of enzymes, chemicals and materials. Curr Opin Biotechnol 2019; 59:65-70. [DOI: 10.1016/j.copbio.2019.02.010] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 01/28/2019] [Accepted: 02/09/2019] [Indexed: 02/02/2023]
|