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Buffi M, Cailleau G, Kuhn T, Li Richter XY, Stanley CE, Wick LY, Chain PS, Bindschedler S, Junier P. Fungal drops: a novel approach for macro- and microscopic analyses of fungal mycelial growth. MICROLIFE 2023; 4:uqad042. [PMID: 37965130 PMCID: PMC10642649 DOI: 10.1093/femsml/uqad042] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 10/11/2023] [Accepted: 10/17/2023] [Indexed: 11/16/2023]
Abstract
This study presents an inexpensive approach for the macro- and microscopic observation of fungal mycelial growth. The 'fungal drops' method allows to investigate the development of a mycelial network in filamentous microorganisms at the colony and hyphal scales. A heterogeneous environment is created by depositing 15-20 µl drops on a hydrophobic surface at a fixed distance. This system is akin to a two-dimensional (2D) soil-like structure in which aqueous-pockets are intermixed with air-filled pores. The fungus (spores or mycelia) is inoculated into one of the drops, from which hyphal growth and exploration take place. Hyphal structures are assessed at different scales using stereoscopic and microscopic imaging. The former allows to evaluate the local response of regions within the colony (modular behaviour), while the latter can be used for fractal dimension analyses to describe the hyphal network architecture. The method was tested with several species to underpin the transferability to multiple species. In addition, two sets of experiments were carried out to demonstrate its use in fungal biology. First, mycelial reorganization of Fusarium oxysporum was assessed as a response to patches containing different nutrient concentrations. Second, the effect of interactions with the soil bacterium Pseudomonas putida on habitat colonization by the same fungus was assessed. This method appeared as fast and accessible, allowed for a high level of replication, and complements more complex experimental platforms. Coupled with image analysis, the fungal drops method provides new insights into the study of fungal modularity both macroscopically and at a single-hypha level.
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Affiliation(s)
- Matteo Buffi
- Laboratory of Microbiology, University of Neuchâtel, Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland
| | - Guillaume Cailleau
- Laboratory of Microbiology, University of Neuchâtel, Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland
| | - Thierry Kuhn
- Laboratory of Microbiology, University of Neuchâtel, Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland
- Laboratory of Eco-Ethology, University of Neuchâtel, Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland
| | - Xiang-Yi Li Richter
- Laboratory of Microbiology, University of Neuchâtel, Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland
- Laboratory of Eco-Ethology, University of Neuchâtel, Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland
| | - Claire E Stanley
- Department of Bioengineering, Imperial College London, B304, Bessemer Building, South Kensington Campus, SW7 2AZ, London, United Kingdom
| | - Lukas Y Wick
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318 Leipzig, Germany
| | - Patrick S Chain
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, P.O. Box 1663, NM 87545, United States
| | - Saskia Bindschedler
- Laboratory of Microbiology, University of Neuchâtel, Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland
| | - Pilar Junier
- Laboratory of Microbiology, University of Neuchâtel, Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland
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Dinius A, Kozanecka ZJ, Hoffmann KP, Krull R. Intensification of bioprocesses with filamentous microorganisms. PHYSICAL SCIENCES REVIEWS 2023. [DOI: 10.1515/psr-2022-0112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Abstract
Many industrial biotechnological processes use filamentous microorganisms to produce platform chemicals, proteins, enzymes and natural products. Product formation is directly linked to their cellular morphology ranging from dispersed mycelia over loose clumps to compact pellets. Therefore, the adjustment and control of the filamentous cellular morphology pose major challenges for bioprocess engineering. Depending on the filamentous strain and desired product, optimal morphological shapes for achieving high product concentrations vary. However, there are currently no overarching strain- or product-related correlations to improve process understanding of filamentous production systems. The present book chapter summarizes the extensive work conducted in recent years in the field of improving product formation and thus intensifying biotechnological processes with filamentous microorganisms. The goal is to provide prospective scientists with an extensive overview of this scientifically diverse, highly interesting field of study. In the course of this, multiple examples and ideas shall facilitate the combination of their acquired expertise with promising areas of future research. Therefore, this overview describes the interdependence between filamentous cellular morphology and product formation. Moreover, the currently most frequently used experimental techniques for morphological structure elucidation will be discussed in detail. Developed strategies of morphology engineering to increase product formation by tailoring and controlling cellular morphology and thus to intensify processes with filamentous microorganisms will be comprehensively presented and discussed.
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Affiliation(s)
- Anna Dinius
- Institute of Biochemical Engineering , Technische Universität Braunschweig , Rebenring 56 , 38106 Braunschweig , Germany
- Center of Pharmaceutical Engineering , Technische Universität Braunschweig , Franz-Liszt-Str. 35a , 38106 Braunschweig , Germany
| | - Zuzanna J. Kozanecka
- Institute of Biochemical Engineering , Technische Universität Braunschweig , Rebenring 56 , 38106 Braunschweig , Germany
- Center of Pharmaceutical Engineering , Technische Universität Braunschweig , Franz-Liszt-Str. 35a , 38106 Braunschweig , Germany
| | - Kevin P. Hoffmann
- Institute of Biochemical Engineering , Technische Universität Braunschweig , Rebenring 56 , 38106 Braunschweig , Germany
- Center of Pharmaceutical Engineering , Technische Universität Braunschweig , Franz-Liszt-Str. 35a , 38106 Braunschweig , Germany
| | - Rainer Krull
- Institute of Biochemical Engineering , Technische Universität Braunschweig , Rebenring 56 , 38106 Braunschweig , Germany
- Center of Pharmaceutical Engineering , Technische Universität Braunschweig , Franz-Liszt-Str. 35a , 38106 Braunschweig , Germany
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Roberts N, Adamatzky A. Mining logical circuits in fungi. Sci Rep 2022; 12:15930. [PMID: 36151275 PMCID: PMC9508188 DOI: 10.1038/s41598-022-20080-3] [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: 08/13/2021] [Accepted: 09/08/2022] [Indexed: 11/23/2022] Open
Abstract
Living substrates are capable for nontrivial mappings of electrical signals due to the substrate nonlinear electrical characteristics. This property can be used to realise Boolean functions. Input logical values are represented by amplitude or frequency of electrical stimuli. Output logical values are decoded from electrical responses of living substrates. We demonstrate how logical circuits can be implemented in mycelium bound composites. The mycelium bound composites (fungal materials) are getting growing recognition as building, packaging, decoration and clothing materials. Presently the fungal materials are passive. To make the fungal materials adaptive, i.e. sensing and computing, we should embed logical circuits into them. We demonstrate experimental laboratory prototypes of many-input Boolean functions implemented in fungal materials from oyster fungi P. ostreatus. We characterise complexity of the functions discovered via complexity of the space-time configurations of one-dimensional cellular automata governed by the functions. We show that the mycelium bound composites can implement representative functions from all classes of cellular automata complexity including the computationally universal. The results presented will make an impact in the field of unconventional computing, experimental demonstration of purposeful computing with fungi, and in the field of intelligent materials, as the prototypes of computing mycelium bound composites.
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Affiliation(s)
- Nic Roberts
- Unconventional Computing Laboratory, UWE, Bristol, UK.
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4
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Miyazawa K, Umeyama T, Hoshino Y, Abe K, Miyazaki Y. Quantitative Monitoring of Mycelial Growth of Aspergillus fumigatus in Liquid Culture by Optical Density. Microbiol Spectr 2022; 10:e0006321. [PMID: 34985327 PMCID: PMC8729762 DOI: 10.1128/spectrum.00063-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 11/17/2021] [Indexed: 01/24/2023] Open
Abstract
Filamentous fungi form multicellular hyphae, which generally form pellets in liquid shake cultures, during the vegetative growth stage. Because of these characteristics, growth-monitoring methods commonly used in bacteria and yeast have not been applied to filamentous fungi. We have recently revealed that the cell wall polysaccharide α-1,3-glucan and extracellular polysaccharide galactosaminogalactan (GAG) contribute to hyphal aggregation in Aspergillus oryzae. Here, we tested whether Aspergillus fumigatus shows dispersed growth in liquid media that can be quantitatively monitored, similar to that of yeasts. We constructed a double disruptant mutant of both the primary α-1,3-glucan synthase gene ags1 and the putative GAG synthase gene gtb3 in A. fumigatus AfS35 and found that the hyphae of this mutant were fully dispersed. Although the mutant lost α-1,3-glucan and GAG, its growth and susceptibility to antifungal agents were not different from those of the parental strain. Mycelial weight of the mutant in shake-flask cultures was proportional to optical density for at least 18 h. We were also able to quantify the dose response of hyphal growth to antifungal agents by measuring optical density. Overall, we established a convenient strategy to monitor A. fumigatus hyphal growth. Our method can be directly used for screening for novel antifungals against Aspergillus species. IMPORTANCE Filamentous fungi generally form hyphal pellets in liquid culture. This property prevents filamentous fungi so that we may apply the methods used for unicellular organisms such as yeast and bacteria. In the present study, by using the fungal pathogen Aspergillus fumigatus strain with modified hyphal surface polysaccharides, we succeeded in monitoring the hyphal growth quantitatively by optical density. The principle of this easy measurement by optical density could lead to a novel standard of hyphal quantification such as those that have been used for yeasts and bacteria. Dose response of hyphal growth by antifungal agents could also be monitored. This method could be useful for screening for novel antifungal reagents against Aspergillus species.
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Affiliation(s)
- Ken Miyazawa
- Department of Fungal Infection, National Institute of Infectious Diseases, Tokyo, Japan
| | - Takashi Umeyama
- Department of Fungal Infection, National Institute of Infectious Diseases, Tokyo, Japan
| | - Yasutaka Hoshino
- Department of Fungal Infection, National Institute of Infectious Diseases, Tokyo, Japan
| | - Keietsu Abe
- Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Yoshitsugu Miyazaki
- Department of Fungal Infection, National Institute of Infectious Diseases, Tokyo, Japan
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Lee SK, Lee JH, Kim HR, Chun Y, Lee JH, Park C, Yoo HY, Kim SW. Rapid and concise quantification of mycelial growth by microscopic image intensity model and application to mass cultivation of fungi. Sci Rep 2021; 11:24157. [PMID: 34921189 PMCID: PMC8683468 DOI: 10.1038/s41598-021-03512-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 11/30/2021] [Indexed: 11/16/2022] Open
Abstract
The microbial food fermentation industry requires real-time monitoring and accurate quantification of cells. However, filamentous fungi are difficult to quantify as they have complex cell types such as pellet, spores, and dispersed hyphae. In this study, numerous data of microscopic image intensity (MII) were used to develop a simple and accurate quantification method of Cordyceps mycelium. The dry cell weight (DCW) of the sample collected during the fermentation was measured. In addition, the intensity values were obtained through the ImageJ program after converting the microscopic images. The prediction model obtained by analyzing the correlation between MII and DCW was evaluated through a simple linear regression method and found to be statistically significant (R2 = 0.941, p < 0.001). In addition, validation with randomly selected samples showed significant accuracy, thus, this model is expected to be used as a valuable tool for predicting and quantifying fungal growth in various industries.
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Affiliation(s)
- Soo Kweon Lee
- Department of Chemical and Biological Engineering, Korea University, 145, Anam-Ro, Seongbuk-Gu, Seoul, 02841, Republic of Korea
| | - Ju Hun Lee
- Department of Chemical and Biological Engineering, Korea University, 145, Anam-Ro, Seongbuk-Gu, Seoul, 02841, Republic of Korea
| | - Hyeong Ryeol Kim
- Department of Chemical and Biological Engineering, Korea University, 145, Anam-Ro, Seongbuk-Gu, Seoul, 02841, Republic of Korea
| | - Youngsang Chun
- Department of Interdisciplinary Bio-Micro System Technology, College of Engineering, Korea University, 145 Anam-Ro, Seongbuk-Gu, Seoul, 02841, Republic of Korea
| | - Ja Hyun Lee
- Department of Food Science and Engineering, Dongyang Mirae University, 445, Gyeongin-Ro, Guro-Gu, Seoul, Republic of Korea
| | - Chulhwan Park
- Department of Chemical Engineering, Kwangwoon University, 20 Kwangwoon-Ro, Nowon-Gu, Seoul, 01897, Republic of Korea.
| | - Hah Young Yoo
- Department of Biotechnology, Sangmyung University, 20, Hongjimun 2-Gil, Jongno-Gu, Seoul, 03016, Republic of Korea.
| | - Seung Wook Kim
- Department of Chemical and Biological Engineering, Korea University, 145, Anam-Ro, Seongbuk-Gu, Seoul, 02841, Republic of Korea.
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Shaghaleh H, Hamoud YA, Xu X, Liu H, Wang S, Sheteiwy M, Dong F, Guo L, Qian Y, Li P, Zhang S. Thermo-/pH-responsive preservative delivery based on TEMPO cellulose nanofiber/cationic copolymer hydrogel film in fruit packaging. Int J Biol Macromol 2021; 183:1911-1924. [PMID: 34097955 DOI: 10.1016/j.ijbiomac.2021.05.208] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 05/30/2021] [Accepted: 05/31/2021] [Indexed: 10/21/2022]
Abstract
Hydrogels have great potential in food packaging. However, stimuli-responsive preservative delivery-based hydrogels for emerging active packaging have not yet been explored. Herein, Unprecedented pH/temperature-responsive hydrogel films for emerging active climacteric fruit packaging were developed based on TEMPO-oxidized nanofibrillated cellulose (TOCNFs) from wheat straw with food-grade cationic-modified poly(N-isopropyl acrylamide-co-acrylamide) (CPNIPAM-AM). TOCNF incorporation into CPNIPAM-AM revealed desirable enhancement of characterization, antimicrobial properties, and pH/thermal-responsive behaviour. In-vitro delivery and release mechanism studies with natamycin revealed the fastest release rates in preferred low pH media, up to 32.1 times higher than that under neutral conditions via anomalous diffusion. Applying a thermal stimulus increased natamycin release rates, providing 1.5-21% gradual-additional pulses by Fickian diffusion. The final hydrogel film showed efficient decay control in response to stimuli of the climacteric fruit environment with safe, recyclable, and feasible application demonstrating the significant potential to be used as an alternative-sustainable material for stimuli-triggered preservative delivery in climacteric fruit packaging.
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Affiliation(s)
- Hiba Shaghaleh
- College of Chemical Engineering, Jiangsu Provincial Key Lab for the Chemistry and Utilization of Agro-forest Biomass, Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Jiangsu Key Lab of Biomass-based Green Fuels and Chemicals, Nanjing Forestry University, Nanjing 210037, China; Institute of Chemical Industry of Forestry Products, Chinese Academy of Forestry, Nanjing 210042, China
| | - Yousef Alhaj Hamoud
- College of Agricultural Science and Engineering, Hohai University, Nanjing 210098, China
| | - Xu Xu
- College of Chemical Engineering, Jiangsu Provincial Key Lab for the Chemistry and Utilization of Agro-forest Biomass, Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Jiangsu Key Lab of Biomass-based Green Fuels and Chemicals, Nanjing Forestry University, Nanjing 210037, China.
| | - He Liu
- Institute of Chemical Industry of Forestry Products, Chinese Academy of Forestry, Nanjing 210042, China.
| | - Shifa Wang
- College of Chemical Engineering, Jiangsu Provincial Key Lab for the Chemistry and Utilization of Agro-forest Biomass, Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Jiangsu Key Lab of Biomass-based Green Fuels and Chemicals, Nanjing Forestry University, Nanjing 210037, China.
| | - Mohamed Sheteiwy
- Department of Agronomy, Faculty of Agriculture, Mansoura University, Mansoura 35516, Egypt; Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Science, Nanjing 210014, China
| | - Fuhao Dong
- College of Chemical Engineering, Jiangsu Provincial Key Lab for the Chemistry and Utilization of Agro-forest Biomass, Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Jiangsu Key Lab of Biomass-based Green Fuels and Chemicals, Nanjing Forestry University, Nanjing 210037, China
| | - Lizhen Guo
- College of Chemical Engineering, Jiangsu Provincial Key Lab for the Chemistry and Utilization of Agro-forest Biomass, Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Jiangsu Key Lab of Biomass-based Green Fuels and Chemicals, Nanjing Forestry University, Nanjing 210037, China
| | - Yuehan Qian
- College of Chemical Engineering, Jiangsu Provincial Key Lab for the Chemistry and Utilization of Agro-forest Biomass, Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Jiangsu Key Lab of Biomass-based Green Fuels and Chemicals, Nanjing Forestry University, Nanjing 210037, China
| | - Pengfei Li
- Guangxi Key Laboratory of Chemistry and Engineering of Forest Products, Guangxi Collaborative Innovation Center for Chemistry and Engineering of Forest Products, Guangxi University for Nationalities, Nanning 530006, China
| | - Shuangsheng Zhang
- College of Chemical Engineering, Jiangsu Provincial Key Lab for the Chemistry and Utilization of Agro-forest Biomass, Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Jiangsu Key Lab of Biomass-based Green Fuels and Chemicals, Nanjing Forestry University, Nanjing 210037, China
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8
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Adamatzky A, Tegelaar M, Wosten HA, Powell AL, Beasley AE, Mayne R. On Boolean gates in fungal colony. Biosystems 2020; 193-194:104138. [DOI: 10.1016/j.biosystems.2020.104138] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 03/27/2020] [Accepted: 03/27/2020] [Indexed: 12/21/2022]
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Kolláth IS, Molnár ÁP, Soós Á, Fekete E, Sándor E, Kovács B, Kubicek CP, Karaffa L. Manganese Deficiency Is Required for High Itaconic Acid Production From D-Xylose in Aspergillus terreus. Front Microbiol 2019; 10:1589. [PMID: 31338087 PMCID: PMC6629873 DOI: 10.3389/fmicb.2019.01589] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 06/26/2019] [Indexed: 12/30/2022] Open
Abstract
Itaconic acid is used as a bio-based, renewable building block in the polymer industry. It is produced by submerged fermentations of the filamentous fungus Aspergillus terreus from molasses or starch, but research over the efficient utilization of non-food, lignocellulosic plant biomass is soaring. The objective of this study was to test whether the application of two key cultivation parameters for obtaining itaconic acid from D-glucose in high yields - Mn2+ ion deficiency and high concentration of the carbon source - would also occur on D-xylose, the principal monomer of lignocellulose. To this end, a carbon and energy balance for itaconic acid formation was established, which is 0.83 moles/mole D-xylose. The effect of Mn2+ ions on itaconic acid formation was indeed similar to that on D-glucose and maximal yields were obtained below 3 μg L-1 Mn2+ ions, which were, however, only 0.63 moles of itaconic acid per mole D-xylose. In contrast to the case on D-glucose, increasing D-xylose concentration over 50 g L-1 did not change the above yield. By-products such as xylitol and α-ketoglutarate were found, but in total they remained below 2% of the concentration of D-xylose. Mass balance of the fermentation with 110 g L-1 D-xylose revealed that >95% of the carbon from D-xylose was accounted as biomass, itaconic acid, and the carbon dioxide released in the last step of itaconic acid biosynthesis. Our data show that the efficiency of biomass formation is the critical parameter for itaconic acid yield from D-xylose under otherwise optimal conditions.
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Affiliation(s)
- István S. Kolláth
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Ákos P. Molnár
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Áron Soós
- Institute of Food Science, Faculty of Agricultural and Food Science and Environmental Management, University of Debrecen, Debrecen, Hungary
| | - Erzsébet Fekete
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Erzsébet Sándor
- Institute of Food Science, Faculty of Agricultural and Food Science and Environmental Management, University of Debrecen, Debrecen, Hungary
| | - Béla Kovács
- Institute of Food Science, Faculty of Agricultural and Food Science and Environmental Management, University of Debrecen, Debrecen, Hungary
| | - Christian P. Kubicek
- Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Vienna, Austria
| | - Levente Karaffa
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
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Cairns TC, Zheng X, Zheng P, Sun J, Meyer V. Moulding the mould: understanding and reprogramming filamentous fungal growth and morphogenesis for next generation cell factories. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:77. [PMID: 30988699 PMCID: PMC6446404 DOI: 10.1186/s13068-019-1400-4] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 03/09/2019] [Indexed: 05/21/2023]
Abstract
Filamentous fungi are harnessed as cell factories for the production of a diverse range of organic acids, proteins, and secondary metabolites. Growth and morphology have critical implications for product titres in both submerged and solid-state fermentations. Recent advances in systems-level understanding of the filamentous lifestyle and development of sophisticated synthetic biological tools for controlled manipulation of fungal genomes now allow rational strain development programs based on data-driven decision making. In this review, we focus on Aspergillus spp. and other industrially utilised fungi to summarise recent insights into the multifaceted and dynamic relationship between filamentous growth and product titres from genetic, metabolic, modelling, subcellular, macromorphological and process engineering perspectives. Current progress and knowledge gaps with regard to mechanistic understanding of product secretion and export from the fungal cell are discussed. We highlight possible strategies for unlocking lead genes for rational strain optimizations based on omics data, and discuss how targeted genetic manipulation of these candidates can be used to optimise fungal morphology for improved performance. Additionally, fungal signalling cascades are introduced as critical processes that can be genetically targeted to control growth and morphology during biotechnological applications. Finally, we review progress in the field of synthetic biology towards chassis cells and minimal genomes, which will eventually enable highly programmable filamentous growth and diversified production capabilities. Ultimately, these advances will not only expand the fungal biotechnology portfolio but will also significantly contribute to a sustainable bio-economy.
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Affiliation(s)
- Timothy C. Cairns
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 People’s Republic of China
| | - Xiaomei Zheng
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 People’s Republic of China
| | - Ping Zheng
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 People’s Republic of China
| | - Jibin Sun
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 People’s Republic of China
| | - Vera Meyer
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- Department of Applied and Molecular Microbiology, Institute of Biotechnology, Technische Universität Berlin, 13355 Berlin, Germany
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Nevalainen H, Peterson R, Curach N. Overview of Gene Expression Using Filamentous Fungi. ACTA ACUST UNITED AC 2019; 92:e55. [PMID: 30040195 DOI: 10.1002/cpps.55] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Filamentous fungi are lower eukaryotes increasingly used for expression of foreign proteins ranging from industrial enzymes originating from other fungi and bacteria to proteins of mammalian origin, such as antibodies and growth factors. Their strengths include an excellent capacity for protein secretion and their eukaryotic protein processing machinery. Proteins secreted from filamentous fungi are modified in the secretory pathway, with folding, proteolytic processing, and addition of glycans being the main modifications. Unlike from many other expression systems, however, plasmids and host strains for expression of gene products in filamentous fungi are not readily available commercially, and the expression system must thus be stitched together in the laboratory. In this overview, the key elements of fungal expression systems are discussed from a practical point of view and with a view towards the future. The principles and considerations presented here can be applied to a range of filamentous fungi. © 2018 by John Wiley & Sons, Inc.
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Affiliation(s)
- Helena Nevalainen
- Department of Molecular Sciences, Macquarie University, Sydney, Australia.,Biomolecular Discovery and Design Research Centre, Macquarie University, Sydney, Australia
| | - Robyn Peterson
- Department of Molecular Sciences, Macquarie University, Sydney, Australia.,Biomolecular Discovery and Design Research Centre, Macquarie University, Sydney, Australia
| | - Natalie Curach
- Department of Molecular Sciences, Macquarie University, Sydney, Australia
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Rajković KM, Milošević NT, Otašević S, Jeremić S, Arsenijević VA. Aspergillus fumigatus branching complexity in vitro: 2D images and dynamic modeling. Comput Biol Med 2018; 104:215-219. [PMID: 30529573 DOI: 10.1016/j.compbiomed.2018.11.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Revised: 11/27/2018] [Accepted: 11/27/2018] [Indexed: 11/18/2022]
Abstract
BACKGROUND Aspergillus fumigatus causes serious infections in humans, and its virulence correlates with hyphal growth, branching and formation of the filamentous mycelium. The filamentous mycelium is a complex structure inconvenient for quantity analysis. In this study, we monitored the branching of A. fumigatus filamentous mycelium in vitro at different points in time in order to assess the complexity degree and develop a dynamic model for the branching complexity. METHOD We used fractal analysis of microscopic images (FAMI) to measure the fractal dimensions (D) of the branching complexity within 24 h of incubation. RESULTS By photographing the filamentous mycelium dynamically and processing the images, the D variation curve of A. fumigatus complexity degree was obtained. We acquired the D variation curve which contained initial exponential period and stationary period of A. fumigatus branching. Further, the obtained data of D was modeled via the logistic model (LM) to develop a dynamic model of A. fumigatus branching for the prediction of the specific growth rate of branching value (0.23 h-1). CONCLUSIONS Developed FAMI and LM models present a simple and non-destructive method of predicting the evolution of branching complexity of A. fumigatus. These models are useful as laboratory measurements for the prediction of hyphal and mycelium development, especially relevant to the pathogenesis study of aspergillosis, as well as pathogenesis of other diseases caused by moulds.
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Affiliation(s)
- Katarina M Rajković
- Institute of Microbiology and Immunology, Faculty of Medicine University of Belgrade, Serbia; College of Applied Studies of Technics and Technology, Kruševac, Serbia
| | - Nebojša T Milošević
- Department of Biophysics, Faculty of Medicine, University of Belgrade, Serbia
| | - Suzana Otašević
- Institute of Microbiology and Immunology, Faculty of Medicine University of Niš, Serbia, Public Health Institute-Niš, Serbia
| | - Sanja Jeremić
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Serbia
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Morphology-driven downscaling of Streptomyces lividans to micro-cultivation. Antonie van Leeuwenhoek 2017; 111:457-469. [PMID: 29094245 PMCID: PMC5816114 DOI: 10.1007/s10482-017-0967-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Accepted: 10/19/2017] [Indexed: 11/20/2022]
Abstract
Actinobacteria are prolific producers of secondary metabolites and industrially relevant enzymes. Growth of these mycelial micro-organisms in small culture volumes is challenging due to their complex morphology. Since morphology and production are typically linked, scaling down culture volumes requires better control over morphogenesis. In larger scale platforms, ranging from shake flasks to bioreactors, the hydrodynamics play an important role in shaping the morphology and determining product formation. Here, we report on the effects of agitation on the mycelial morphology of Streptomyces lividans grown in microtitre plates. Our work shows that at the appropriate agitation rates cultures can be scaled down to volumes as small as 100 µl while maintaining the same morphology as seen in larger scale platforms. Using image analysis and principal component analysis we compared the morphologies of the cultures; when agitated at 1400–1600 rpm the mycelial morphology in micro-cultures was similar to that obtained in shake flasks, while product formation was also maintained. Our study shows that the morphology of actinobacteria in micro-cultures can be controlled in a similar manner as in larger scale cultures by carefully controlling the mixing rate. This could facilitate high-throughput screening and upscaling.
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Munialo CD, van der Linden E, Ako K, Nieuwland M, Van As H, de Jongh HH. The effect of polysaccharides on the ability of whey protein gels to either store or dissipate energy upon mechanical deformation. Food Hydrocoll 2016. [DOI: 10.1016/j.foodhyd.2015.08.013] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
Filamentous fungi play an important role not only in the bio-manufacturing of value-added products, but also in bioenergy and environmental research. The bioprocess manipulation of filamentous fungi is more difficult than that of other microbial species because of their different pellet morphologies and the presence of tangled mycelia under different cultivation conditions. Fungal pellets, which have the advantages of harvest ease, low fermentation broth viscosity and high yield of some proteins, have been used for a long time. Many attempts have been made to establish the relationship between pellet and product yield using quantitative approaches. Fungal pellet formation is attributed to the combination of electrostatic interactions, hydrophobicity and specific interactions from spore wall components. Electrostatic interactions result from van der Waals forces and negative charge repulsion from carboxyl groups in the spore wall structure. Electrostatic interactions are also affected by counter-ions (cations) and the physiologic conditions of spores that modify the carboxyl groups. Fungal aggregates are promoted by the hydrophobicity generated by hydrophobins, which form a hydrophobic coat that covers the spore. The specific interactions of spore wall components contribute to spore aggregation through salt bridging. A model of spore aggregation was proposed based on these forces. Additionally, some challenges were addressed, including the limitations of research techniques, the quantitative determination of forces and the complex information of biological systems, to clarify the mechanism of fungal pellet formation.
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Affiliation(s)
- Jianguo Zhang
- a School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology and
| | - Jining Zhang
- b Eco-environmental Protection Research Institute, Shanghai Academy of Agricultural Sciences , Shanghai , China
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Walisko R, Moench-Tegeder J, Blotenberg J, Wucherpfennig T, Krull R. The Taming of the Shrew--Controlling the Morphology of Filamentous Eukaryotic and Prokaryotic Microorganisms. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2015; 149:1-27. [PMID: 25796624 DOI: 10.1007/10_2015_322] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
One of the most sensitive process characteristics in the cultivation of filamentous biological systems is their complex morphology. In submerged cultures, the observed macroscopic morphology of filamentous microorganisms varies from freely dispersed mycelium to dense spherical pellets consisting of a more or less dense, branched and partially intertwined network of hyphae. Recently, the freely dispersed mycelium form has been in high demand for submerged cultivation because this morphology enhances the growth and production of several valuable products. A distinct filamentous morphology and productivity are influenced by the environment and can be controlled by inoculum concentration, spore viability, pH value, cultivation temperature, dissolved oxygen concentration, medium composition, mechanical stress or process mode as well as through the addition of inorganic salts or microparticles, which provides the opportunity to tailor a filamentous morphology. The suitable morphology for a given bioprocess varies depending on the desired product. Therefore, the advantages and disadvantages of each morphological type should be carefully evaluated for every biological system. Because of the high industrial relevance of filamentous microorganisms, research in previous years has aimed at the development of tools and techniques to characterise their growth and obtain quantitative estimates of their morphological properties. The focus of this review is on current advances in the characterisation and control of filamentous morphology with a separation of eukaryotic and prokaryotic systems. Furthermore, recent strategies to tailor the morphology through classical biochemical process parameters, morphology and genetic engineering to optimise the productivity of these filamentous systems are discussed.
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Affiliation(s)
- Robert Walisko
- Institute of Biochemical Engineering, Technische Universität Braunschweig, Gaußstraße 17, 38106, Braunschweig, Germany,
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17
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Improvement of glucoamylase production using axial impellers with low power consumption and homogeneous mass transfer. Biochem Eng J 2015. [DOI: 10.1016/j.bej.2015.03.025] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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18
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De Gracia M, Cascales M, Expert P, Bellanger MN, Le Cam B, Lemaire C. How Did Host Domestication Modify Life History Traits of Its Pathogens? PLoS One 2015; 10:e0122909. [PMID: 26091067 PMCID: PMC4475019 DOI: 10.1371/journal.pone.0122909] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 02/16/2015] [Indexed: 01/08/2023] Open
Abstract
Understanding evolutionary dynamics of pathogens during domestication of their hosts and rise of agro-ecosystems is essential for durable disease management. Here, we investigated changes in life-history traits of the fungal pathogen Venturia inaequalis during domestication of the apple. Life traits linked to fungal dispersal were compared between 60 strains that were sampled in domestic and wild habitats in Kazakhstan, the center of origin of both host and pathogen. Our two main findings are that transition from wild to agro-ecosystems was associated with an increase of both spore size and sporulation capacity; and that distribution of quantitative traits of the domestic population mostly overlapped with those of the wild population. Our results suggest that apple domestication had a considerable impact on fungal characters linked to its dispersal through selection from standing phenotypic diversity. We showed that pestification of V. inaequalis in orchards led to an enhanced allocation in colonization ability from standing variation in the wild area. This study emphasizes the potential threat that pathogenic fungal populations living in wild environments represent for durability of resistance in agro-ecosystems.
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Affiliation(s)
- Marie De Gracia
- INRA, IRHS, SFR QUASAV, Beaucouzé, 49071, France
- Université d’Angers, IRHS, PRES UNAM, SFR QUASAV, Angers, 49045, France
- Agrocampus Ouest, IRHS, SFR QUASAV, Angers, 49045, France
| | - Mathilde Cascales
- INRA, IRHS, SFR QUASAV, Beaucouzé, 49071, France
- Université d’Angers, IRHS, PRES UNAM, SFR QUASAV, Angers, 49045, France
- Agrocampus Ouest, IRHS, SFR QUASAV, Angers, 49045, France
| | - Pascale Expert
- INRA, IRHS, SFR QUASAV, Beaucouzé, 49071, France
- Université d’Angers, IRHS, PRES UNAM, SFR QUASAV, Angers, 49045, France
- Agrocampus Ouest, IRHS, SFR QUASAV, Angers, 49045, France
| | - Marie-Noelle Bellanger
- INRA, IRHS, SFR QUASAV, Beaucouzé, 49071, France
- Université d’Angers, IRHS, PRES UNAM, SFR QUASAV, Angers, 49045, France
- Agrocampus Ouest, IRHS, SFR QUASAV, Angers, 49045, France
| | - Bruno Le Cam
- INRA, IRHS, SFR QUASAV, Beaucouzé, 49071, France
- Université d’Angers, IRHS, PRES UNAM, SFR QUASAV, Angers, 49045, France
- Agrocampus Ouest, IRHS, SFR QUASAV, Angers, 49045, France
| | - Christophe Lemaire
- INRA, IRHS, SFR QUASAV, Beaucouzé, 49071, France
- Université d’Angers, IRHS, PRES UNAM, SFR QUASAV, Angers, 49045, France
- Agrocampus Ouest, IRHS, SFR QUASAV, Angers, 49045, France
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19
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Barrera GN, Calderón-Domínguez G, Chanona-Pérez J, Gutiérrez-López GF, León AE, Ribotta PD. Evaluation of the mechanical damage on wheat starch granules by SEM, ESEM, AFM and texture image analysis. Carbohydr Polym 2013; 98:1449-57. [DOI: 10.1016/j.carbpol.2013.07.056] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 07/23/2013] [Accepted: 07/24/2013] [Indexed: 10/26/2022]
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21
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Wucherpfennig T, Lakowitz A, Krull R. Comprehension of viscous morphology--evaluation of fractal and conventional parameters for rheological characterization of Aspergillus niger culture broth. J Biotechnol 2012; 163:124-32. [PMID: 23059168 DOI: 10.1016/j.jbiotec.2012.08.027] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Revised: 08/01/2012] [Accepted: 08/06/2012] [Indexed: 11/30/2022]
Abstract
The filamentous fungus Aspergillus niger is a widely used host in industrial processes from food, chemical to pharmaceutical industry. The most prominent feature of this filamentous microorganism in submerged cultivation is its complex morphology which comprises dense spherical pellets as well as viscous elongated filaments. Depending on culture conditions, the exhibited morphology has tremendous effect on the overall process, making a precise understanding of fungal growth and morphology indispensable. Morphology, however, is only industrially relevant as long as it can be linked to important cultivation characteristics of filamentous microorganisms such as culture broth flow behavior. In the present study, different conventional and fractal morphological parameters gained from automatic image analysis were tested for their eligibility to predict culture broth rheology from morphologic appearance. The introduced biomass independent rheological parameters K(BDW) and n(BDW) obtained by power law relationship were successfully estimated from morphology related fractal and conventional parameters. For improved characterization of morphologic appearance of filamentous fungi newly introduced fractal quotient and lacunarity were compared to conventional particle shape parameters in form of the earlier established Morphology number (MN).
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Affiliation(s)
- Thomas Wucherpfennig
- Institute of Biochemical Engineering, Technische Universität Braunschweig, Gaußstraße 17, 38106 Braunschweig, Germany
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22
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Barry DJ. Quantifying the branching frequency of virtual filamentous microbes using fractal analysis. Biotechnol Bioeng 2012; 110:437-47. [DOI: 10.1002/bit.24709] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Revised: 07/31/2012] [Accepted: 08/07/2012] [Indexed: 01/08/2023]
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Espinosa-Mendoza RE, Solorza-Feria J, Arenas-Ocampo ML, Camacho-Díaz BH, Del Villar-Martínez AA, Vanegas-Espinoza PE, Jiménez-Aparicio AR. Morphostructural characterization of rice grain (Oryza sativa L.) variety Morelos A-98 during filling stages. ScientificWorldJournal 2012; 2012:940293. [PMID: 22645473 PMCID: PMC3356751 DOI: 10.1100/2012/940293] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Accepted: 01/03/2012] [Indexed: 11/19/2022] Open
Abstract
The morphostructure of grain rice Morelos A-98 was characterized in five stages of physiological maturation, in order to generate morphometric information during the filling process. Micrographic images from optical and scanning electron microscopy coupled to a digital capture system were used. Images were digitally processed to measure different descriptors such as shape, fractal dimension, and surface texture. Results showed that, two weeks after anthesis, an accelerated grain filling was observed, particularly on those grains positioned in the distal panicle zone, compared to those located in the base of this one. As deposition of assimilates in the grain increased, the area and perimeter of the transversal cut of the grains also increased (P ≤ 0.05); meanwhile, the rounded shape factor tended to increase as well (P ≤ 0.05), while the elliptic shape factor decreased. As the dehydrated endosperm passed from “milky” to “doughy” stages, values of fractal dimension area and endosperm perimeter as well as surface texture values showed that grain borders tended to become smoother and that there was a greater structured endosperm area (P ≤ 0.05).
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Affiliation(s)
- Rosa Elena Espinosa-Mendoza
- Centro de Desarrollo de Productos Bióticos, IPN, Carretera Yautepec-Jojutla Km 6, Calle CEPROBI No. 8, San Isidro, 62731 Yautepec, Mor, Mexico
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24
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Sin MLY, Liu T, Pyne JD, Gau V, Liao JC, Kin Wong P. In situ electrokinetic enhancement for self-assembled-monolayer-based electrochemical biosensing. Anal Chem 2012; 84:2702-7. [PMID: 22397486 PMCID: PMC4069200 DOI: 10.1021/ac203245j] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
This study reports a multifunctional electrode approach which directly implements electrokinetic enhancement on a self-assembled-monolayer-based electrochemical sensor for point-of-care diagnostics. Using urinary tract infections as a model system, we demonstrate that electrokinetic enhancement, which involves in situ stirring and heating, can enhance the sensitivity of the strain specific 16S rRNA hybridization assay for 1 order of magnitude and accelerate the time-limiting incubation step with a 6-fold reduction in the incubation time. Since the same electrode platform is used for both electrochemical signal enhancement and electrochemical sensing, the multifunctional electrode approach provides a highly effective strategy toward fully integrated lab-on-a-chip systems for various biomedical applications.
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Affiliation(s)
- Mandy L. Y. Sin
- Department of Aerospace and Mechanical Engineering, University of Arizona, Tucson, Arizona 85721, United States
| | - Tingting Liu
- Department of Aerospace and Mechanical Engineering, University of Arizona, Tucson, Arizona 85721, United States
| | - Jeffrey D. Pyne
- Department of Aerospace and Mechanical Engineering, University of Arizona, Tucson, Arizona 85721, United States
| | - Vincent Gau
- GeneFluidics Inc, Irwindale, California 91010, United States
| | - Joseph C. Liao
- Department of Urology, Stanford University, Palo Alto, California 94304, United States
- Veterans Affairs Palo Alto Health Care System, Palo Alto, California 94304, United States
| | - Pak Kin Wong
- Department of Aerospace and Mechanical Engineering, University of Arizona, Tucson, Arizona 85721, United States
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Wucherpfennig T, Lakowitz A, Driouch H, Krull R, Wittmann C. Customization of Aspergillus niger morphology through addition of talc micro particles. J Vis Exp 2012:4023. [PMID: 22453998 PMCID: PMC3539677 DOI: 10.3791/4023] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
The filamentous fungus A. niger is a widely used strain in a broad range of industrial processes from food to pharmaceutical industry. One of the most intriguing and often uncontrollable characteristics of this filamentous organism is its complex morphology. It ranges from dense spherical pellets to viscous mycelia (Figure 1). Various process parameters and ingredients are known to influence fungal morphology 1. Since optimal productivity correlates strongly with a specific morphological form, the fungal morphology often represents the bottleneck of productivity in industrial production. A straight forward and elegant approach to precisely control morphological shape is the addition of inorganic insoluble micro particles (like hydrous magnesium silicate, aluminum oxide or titanium silicate oxide) to the culture medium contributing to increased enzyme production 2-6. Since there is an obvious correlation between micro particle dependent morphology and enzyme production it is desirable to mathematically link productivity and morphological appearance. Therefore a quantitative precise and holistic morphological description is targeted. Thus, we present a method to generate and characterize micro particle dependent morphological structures and to correlate fungal morphology with productivity (Figure 1) which possibly contributes to a better understanding of the morphogenesis of filamentous microorganisms. The recombinant strain A. niger SKAn1015 is cultivated for 72 h in a 3 L stirred tank bioreactor. By addition of talc micro particles in concentrations of 1 g/L, 3 g/L and 10 g/L prior to inoculation a variety of morphological structures is reproducibly generated. Sterile samples are taken after 24, 48 and 72 hours for determination of growth progress and activity of the produced enzyme. The formed product is the high-value enzyme β-fructofuranosidase, an important biocatalyst for neo-sugar formation in food or pharmaceutical industry, which catalyzes among others the reaction of sucrose to glucose 7-9. Therefore, the quantification of glucose after adding sucrose implies the amount of produced β-fructofuranosidase. Glucose quantification is made by a GOD/POD-Assay 10, which is modified for high-throughput analysis in 96-well micro titer plates. Fungal morphology after 72 hours is examined by microscope and characterized by digital image analysis. In doing so, particle shape factors for fungal macro morphology like Feret's diameter, projected area, perimeter, circularity, aspect ratio, roundness und solidity are calculated with the open source image processing program ImageJ. Relevant parameters are combined to a dimensionless Morphology number (Mn) 11, which enables a comprehensive characterization of fungal morphology. The close correlation of the Morphology number and productivity are highlighted by mathematical regression.
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Affiliation(s)
- Thomas Wucherpfennig
- Institute of Biochemical Engineering, Technische Universität Braunschweig, Braunschweig, Germany
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BARRY D, WILLIAMS G. Microscopic characterisation of filamentous microbes: towards fully automated morphological quantification through image analysis. J Microsc 2011; 244:1-20. [DOI: 10.1111/j.1365-2818.2011.03506.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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27
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Wucherpfennig T, Hestler T, Krull R. Morphology engineering--osmolality and its effect on Aspergillus niger morphology and productivity. Microb Cell Fact 2011; 10:58. [PMID: 21801352 PMCID: PMC3178489 DOI: 10.1186/1475-2859-10-58] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2011] [Accepted: 07/29/2011] [Indexed: 05/26/2023] Open
Abstract
Background The filamentous fungus Aspergillus niger is a widely used strain in a broad range of industrial processes from food to pharmaceutical industry. One of the most intriguing and often uncontrollable characteristics of this filamentous organism is its complex morphology, ranging from dense spherical pellets to viscous mycelia depending on culture conditions. Optimal productivity correlates strongly with a specific morphological form, thus making high demands on process control. Results In about 50 2L stirred tank cultivations the influence of osmolality on A. niger morphology and productivity was investigated. The specific productivity of fructofuranosidase producing strain A. niger SKAn 1015 could be increased notably from 0.5 to 9 U mg-1 h-1 around eighteen fold, by increasing the culture broth osmolality by addition of sodium chloride. The specific productivity of glucoamylase producing strain A. niger AB1.13, could be elevated using the same procedure. An optimal producing osmolality was shown to exist well over the standard osmolality at about 3.2 osmol kg-1 depending on the strain. Fungal morphology of all cultivations was examined by microscope and characterized by digital image analysis. Particle shape parameters were combined to a dimensionless Morphology number, which enabled a comprehensive characterization of fungal morphology correlating closely with productivity. A novel method for determination of germination time in submerged cultivations by laser diffraction, introduced in this study, revealed a decelerated germination process with increasing osmolality. Conclusions Through the introduction of the versatile Morphology number, this study provides the means for a desirable characterization of fungal morphology and demonstrates its relation to productivity. Furthermore, osmolality as a fairly new parameter in process engineering is introduced and found to affect fungal morphology and productivity. Osmolality might provide an auspicious and reliable approach to increase the productivity in industrial processes. Because of the predictable behavior fungal morphology showed in dependence of osmolality, a customization of morphology for process needs seems feasible.
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Affiliation(s)
- Thomas Wucherpfennig
- Institute of Biochemical Engineering, Technische Universität Braunschweig, Gaußstraße 17, 38106 Braunschweig, Germany
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Barry DJ, Chan C, Williams GA. Morphological quantification of filamentous fungal development using membrane immobilization and automatic image analysis. J Ind Microbiol Biotechnol 2009; 36:787-800. [PMID: 19277741 DOI: 10.1007/s10295-009-0552-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2008] [Accepted: 02/17/2009] [Indexed: 10/21/2022]
Abstract
Mycelial morphology is a critically important process property in industrial fermentations of filamentous micro-organisms, as particular phenotypes are associated with maximum productivity. However, the accurate quantification of complex morphologies still represents a significant challenge in elucidating this relationship. A system has been developed for high-resolution characterisation of filamentous fungal growth on a solid substrate, using membrane immobilization and fully-automatic plug-ins developed for the public domain, Java-based, image-processing software, ImageJ. The system has been used to quantify the microscopic development of Aspergillus oryzae on malt agar, by measuring spore projected area and circularity, the total length of a hyphal element, the number of tips per element, and the hyphal growth unit. Two different stages of growth are described, from the swelling of a population of conidiospores up to fully developed, branched hyphae 24 h after inoculation. Spore swelling expressed as an increase in mean equivalent spore diameter was found to be approximately linear with time. Widespread germination of spores was observed by 8 h after inoculation. From approximately 12 h, the number of tips was found to increase exponentially. The specific growth rate of a population of hyphae was calculated as approximately 0.24-0.27 h(-1). A wide variation in growth kinetics was found within the population. The robustness of the image-analysis system was verified by testing the effect of small variations in the input data.
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Affiliation(s)
- David J Barry
- School of Biological Sciences, Dublin Institute of Technology, Kevin Street, Dublin 8, Ireland.
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Golinski MR, Boecklen WJ, Dawe AL. Two-dimensional fractal growth properties of the filamentous fungusCryphonectria parasitica: the effects of hypovirus infection. J Basic Microbiol 2008; 48:426-9. [DOI: 10.1002/jobm.200800017] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Ali S. Application of kaolin to improve citric acid production by a thermophilic Aspergillus niger. Appl Microbiol Biotechnol 2006; 73:755-62. [PMID: 16871375 DOI: 10.1007/s00253-006-0533-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2006] [Revised: 05/31/2006] [Accepted: 06/01/2006] [Indexed: 10/24/2022]
Abstract
Citric acid production by a thermophilic strain of the filamentous fungus Aspergillus niger IIB-6 in a medium containing blackstrap cane molasses was improved by the addition of kaolin to the fermentation medium. The fermentation was run in a 7.5-l stirred bioreactor (60% working volume). The optimal sugar concentration was found to be 150 g/l. Kaolin (1.0 ml) was added to the fermentation medium to enhance volumetric production. The best results in terms of product formation were observed when 15 parts per million (ppm) kaolin was added 24 h after inoculation. With added kaolin, citric acid production was enhanced 2.34-fold, compared to a control fermentation without added kaolin. The length of incubation to attain this product yield was shortened from 168 to 96 h. The comparison of kinetic parameters showed improved citrate synthase activity of the culture (Y (p/x)=7.046 g/g). When the culture grown at various kaolin concentrations was monitored for Q (p), Q (s), and q (p), there was significant improvement in these variables over the control. Specific production by the culture (q (p)=0.073 g/g cells/h) was improved several fold. The addition of kaolin substantially improved the enthalpy (DeltaH (D)=74.5 kJ/mol) and entropy of activation (DeltaS=-174 J/mol/K) for citric acid production, free energies for transition state formation, and substrate binding for sucrose hydrolysis. The performance of fuzzy logic control of the bioreactor was found to be very promising for an improvement ( approximately 4.2-fold) in the production of citric acid (96.88 g/l), which is of value in commercial applications.
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Affiliation(s)
- Sikander Ali
- Molecular Genetics and Biotechnology Labs, GC University Lahore, Lahore, Pakistan.
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