1
|
Philipp LA, Bühler K, Ulber R, Gescher J. Beneficial applications of biofilms. Nat Rev Microbiol 2024; 22:276-290. [PMID: 37957398 DOI: 10.1038/s41579-023-00985-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/05/2023] [Indexed: 11/15/2023]
Abstract
Many microorganisms live in the form of a biofilm. Although they are feared in the medical sector, biofilms that are composed of non-pathogenic organisms can be highly beneficial in many applications, including the production of bulk and fine chemicals. Biofilm systems are natural retentostats in which the biocatalysts can adapt and optimize their metabolism to different conditions over time. The adherent nature of biofilms allows them to be used in continuous systems in which the hydraulic retention time is much shorter than the doubling time of the biocatalysts. Moreover, the resilience of organisms growing in biofilms, together with the potential of uncoupling growth from catalytic activity, offers a wide range of opportunities. The ability to work with continuous systems using a potentially self-advancing whole-cell biocatalyst is attracting interest from a range of disciplines, from applied microbiology to materials science and from bioengineering to process engineering. The field of beneficial biofilms is rapidly evolving, with an increasing number of applications being explored, and the surge in demand for sustainable and biobased solutions and processes is accelerating advances in the field. This Review provides an overview of the research topics, challenges, applications and future directions in beneficial and applied biofilm research.
Collapse
Affiliation(s)
- Laura-Alina Philipp
- Hamburg University of Technology, Institute of Technical Microbiology, Hamburg, Germany
| | - Katja Bühler
- Department of Environmental Microbiology, Helmholtz-Centre for Environmental Research, Leipzig, Germany
| | - Roland Ulber
- RPTU Kaiserslautern-Landau, Institute of Bioprocess Engineering, Kaiserslautern, Germany
| | - Johannes Gescher
- Hamburg University of Technology, Institute of Technical Microbiology, Hamburg, Germany.
| |
Collapse
|
2
|
Hueso-Gil A, Calles B, de Lorenzo V. Engineering Green-light-responsive Heterologous Gene Expression in Pseudomonas. Methods Mol Biol 2024; 2721:35-44. [PMID: 37819513 DOI: 10.1007/978-1-0716-3473-8_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/13/2023]
Abstract
Engineering bacterial properties requires precision and fine-tuning for optimal control of the desired application. In consequence, it is essential to accurately turn the function of interest from OFF to ON state and vice versa, avoiding any type of residual activation. For this type of purpose, light switches have revealed a clean and powerful tool in which control does not depend on the addition of chemical compounds that may remain in the media. To reach this degree of directed regulation through light, the switch based on the cyanobacterial two-component system CcaSR system was previously adapted to manipulate Pseudomonas putida for transcription of a gene of interest. In this chapter, we describe how to induce biofilm formation by placing the expression of the c-di-GMP-producing diguanylate cyclase PleD from Caulobacter sp. under the control of the CcaSR system. The regulation through optogenetics accomplished with this protocol promotes higher exploitation of biofilm beneficial features in a cheaper and cleaner way compared to chemical induction.
Collapse
Affiliation(s)
- Angeles Hueso-Gil
- Systems Biology Department, Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA/CSIC), Madrid, Spain
| | - Belén Calles
- Systems Biology Department, Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain
| | - Víctor de Lorenzo
- Systems Biology Department, Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain.
| |
Collapse
|
3
|
Fenibo EO, Selvarajan R, Abia ALK, Matambo T. Medium-chain alkane biodegradation and its link to some unifying attributes of alkB genes diversity. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 877:162951. [PMID: 36948313 DOI: 10.1016/j.scitotenv.2023.162951] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 03/14/2023] [Accepted: 03/15/2023] [Indexed: 05/06/2023]
Abstract
Hydrocarbon footprints in the environment, via biosynthesis, natural seepage, anthropogenic activities and accidents, affect the ecosystem and induce a shift in the healthy biogeochemical equilibrium that drives needed ecological services. In addition, these imbalances cause human diseases and reduce animal and microorganism diversity. Microbial bioremediation, which capitalizes on functional genes, is a sustainable mitigation option for cleaning hydrocarbon-impacted environments. This review focuses on the bacterial alkB functional gene, which codes for a non-heme di‑iron monooxygenase (AlkB) with a di‑iron active site that catalyzes C8-C16 medium-chain alkane metabolism. These enzymes are ubiquitous and share common attributes such as being controlled by global transcriptional regulators, being a component of most super hydrocarbon degraders, and their distributions linked to horizontal gene transfer (HGT) events. The phylogenetic approach used in the HGT detection suggests that AlkB tree topology clusters bacteria functionally and that a preferential gradient dictates gene distribution. The alkB gene also acts as a biomarker for bioremediation, although it is found in pristine environments and absent in some hydrocarbon degraders. For instance, a quantitative molecular method has failed to link alkB copy number to contamination concentration levels. This limitation may be due to AlkB homologues, which have other functions besides n-alkane assimilation. Thus, this review, which focuses on Pseudomonas putida GPo1 alkB, shows that AlkB proteins are diverse but have some unifying trends around hydrocarbon-degrading bacteria; it is erroneous to rely on alkB detection alone as a monitoring parameter for hydrocarbon degradation, alkB gene distribution are preferentially distributed among bacteria, and the plausible explanation for AlkB affiliation to broad-spectrum metabolism of hydrocarbons in super-degraders hitherto reported. Overall, this review provides a broad perspective of the ecology of alkB-carrying bacteria and their directed biodegradation pathways.
Collapse
Affiliation(s)
- Emmanuel Oliver Fenibo
- World Bank Africa Centre of Excellence, Centre for Oilfield Chemical Research, University of Port Harcourt, Port Harcourt 500272, Nigeria
| | - Ramganesh Selvarajan
- Laboratory of Extraterrestrial Ocean Systems (LEOS), Institute of Deep-Sea Science and Engineering, Chinese Academy of Sciences, Sanya, China; Department of Environmental Science, University of South Africa, Florida Campus, 1710, South Africa
| | - Akebe Luther King Abia
- Department of Environmental Science, University of South Africa, Florida Campus, 1710, South Africa; Environmental Research Foundation, Westville 3630, South Africa
| | - Tonderayi Matambo
- Institute for the Development of Energy for African Sustainability, University of South Africa, Roodepoort 1709, South Africa.
| |
Collapse
|
4
|
Sivapuratharasan V, Lenzen C, Michel C, Muthukrishnan AB, Jayaraman G, Blank LM. Metabolic engineering of Pseudomonas taiwanensis VLB120 for rhamnolipid biosynthesis from biomass-derived aromatics. Metab Eng Commun 2022; 15:e00202. [PMID: 36017490 PMCID: PMC9396041 DOI: 10.1016/j.mec.2022.e00202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 07/01/2022] [Accepted: 07/27/2022] [Indexed: 12/02/2022] Open
Abstract
Lignin is a ubiquitously available and sustainable feedstock that is underused as its depolymerization yields a range of aromatic monomers that are challenging substrates for microbes. In this study, we investigated the growth of Pseudomonas taiwanensis VLB120 on biomass-derived aromatics, namely, 4-coumarate, ferulate, 4-hydroxybenzoate, and vanillate. The wild type strain was not able to grow on 4-coumarate and ferulate. After integration of catabolic genes for breakdown of 4-coumarate and ferulate, the metabolically engineered strain was able to grow on these aromatics. Further, the specific growth rate of the strain was enhanced up to 3-fold using adaptive laboratory evolution, resulting in increased tolerance towards 4-coumarate and ferulate. Whole-genome sequencing highlighted several different mutations mainly in two genes. The first gene was actP, coding for a cation/acetate symporter, and the other gene was paaA coding for a phenyl acetyl-CoA oxygenase. The evolved strain was further engineered for rhamnolipid production. Among the biomass-derived aromatics investigated, 4-coumarate and ferulate were promising substrates for product synthesis. With 4-coumarate as the sole carbon source, a yield of 0.27 (Cmolrhl/Cmol4-coumarate) was achieved, corresponding to 28% of the theoretical yield. Ferulate enabled a yield of about 0.22 (Cmolrhl/Cmolferulate), representing 42% of the theoretical yield. Overall, this study demonstrates the use of biomass-derived aromatics as novel carbon sources for rhamnolipid biosynthesis. Enabling 4-coumarate and ferulate degradation in Pseudomonas taiwanensis VLB120. The growth rate and tolerance was enhanced towards non-native substrates. Genetic mutations in actP and paaA contributed to the enhanced tolerance. Production of mono-rhamnolipids was established using all the chosen aromatics.
Collapse
Affiliation(s)
- Vaishnavi Sivapuratharasan
- Institute of Applied Microbiology, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, 600036, India
| | - Christoph Lenzen
- Institute of Applied Microbiology, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany
| | - Carina Michel
- Institute of Applied Microbiology, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany
| | - Anantha Barathi Muthukrishnan
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, 600036, India
| | - Guhan Jayaraman
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, 600036, India
| | - Lars M. Blank
- Institute of Applied Microbiology, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany
- Corresponding author.
| |
Collapse
|
5
|
Carvalho FM, Azevedo A, Ferreira MM, Mergulhão FJM, Gomes LC. Advances on Bacterial and Fungal Biofilms for the Production of Added-Value Compounds. BIOLOGY 2022; 11:biology11081126. [PMID: 36009752 PMCID: PMC9405441 DOI: 10.3390/biology11081126] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 07/21/2022] [Accepted: 07/22/2022] [Indexed: 11/24/2022]
Abstract
Simple Summary The production of bio-based materials, including organic acids, antibiotics, enzymes, ethanol, and hydrogen, is generally done by the cultivation of suspended cells rather than using immobilized cells. However, several studies suggest the application of productive biofilms as a reliable alternative for biocatalysis, with many advantages over suspended-growth systems. This review gives an overview of the breakthrough in the application of biofilm platforms for the sustainable production of valuable compounds, with particular insight into the latest advances in the production of recombinant proteins. Productive biofilms are shown to improve production rates and product yields, demonstrating great potential for industrial applications. Abstract In recent years, abundant research has been performed on biofilms for the production of compounds with biotechnological and industrial relevance. The use of biofilm platforms has been seen as a compelling approach to producing fine and bulk chemicals such as organic acids, alcohols, and solvents. However, the production of recombinant proteins using this system is still scarce. Biofilm reactors are known to have higher biomass density, operational stability, and potential for long-term operation than suspended cell reactors. In addition, there is an increasing demand to harness industrial and agricultural wastes and biorefinery residues to improve process sustainability and reduce production costs. The synthesis of recombinant proteins and other high-value compounds is mainly achieved using suspended cultures of bacteria, yeasts, and fungi. This review discusses the use of biofilm reactors for the production of recombinant proteins and other added-value compounds using bacteria and fungi.
Collapse
Affiliation(s)
- Fábio M. Carvalho
- LEPABE—Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal; (F.M.C.); (A.A.); (M.M.F.); (F.J.M.M.)
- ALiCE—Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Ana Azevedo
- LEPABE—Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal; (F.M.C.); (A.A.); (M.M.F.); (F.J.M.M.)
- ALiCE—Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Marta M. Ferreira
- LEPABE—Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal; (F.M.C.); (A.A.); (M.M.F.); (F.J.M.M.)
- ALiCE—Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Filipe J. M. Mergulhão
- LEPABE—Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal; (F.M.C.); (A.A.); (M.M.F.); (F.J.M.M.)
- ALiCE—Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Luciana C. Gomes
- LEPABE—Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal; (F.M.C.); (A.A.); (M.M.F.); (F.J.M.M.)
- ALiCE—Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
- Correspondence:
| |
Collapse
|
6
|
Williams SC, Austin RN. An Overview of the Electron-Transfer Proteins That Activate Alkane Monooxygenase (AlkB). Front Microbiol 2022; 13:845551. [PMID: 35295299 PMCID: PMC8918992 DOI: 10.3389/fmicb.2022.845551] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 01/24/2022] [Indexed: 11/13/2022] Open
Abstract
Alkane-oxidizing enzymes play an important role in the global carbon cycle. Alkane monooxygenase (AlkB) oxidizes most of the medium-chain length alkanes in the environment. The first AlkB identified was from P. putida GPo1 (initially known as P. oleovorans) in the early 1970s, and it continues to be the family member about which the most is known. This AlkB is found as part of the OCT operon, in which all of the key proteins required for growth on alkanes are present. The AlkB catalytic cycle requires that the diiron active site be reduced. In P. putida GPo1, electrons originate from NADH and arrive at AlkB via the intermediacy of a flavin reductase and an iron–sulfur protein (a rubredoxin). In this Mini Review, we will review what is known about the canonical arrangement of electron-transfer proteins that activate AlkB and, more importantly, point to several other arrangements that are possible. These other arrangements include the presence of a simpler rubredoxin than what is found in the canonical arrangement, as well as two other classes of AlkBs with fused electron-transfer partners. In one class, a rubredoxin is fused to the hydroxylase and in another less well-explored class, a ferredoxin reductase and a ferredoxin are fused to the hydroxylase. We review what is known about the biochemistry of these electron-transfer proteins, speculate on the biological significance of this diversity, and point to key questions for future research.
Collapse
Affiliation(s)
| | - Rachel Narehood Austin
- Department of Chemistry, Barnard College, Columbia University, New York City, NY, United States
- *Correspondence: Rachel Narehood Austin,
| |
Collapse
|
7
|
Pereira MS, de Araújo SS, Nagem RAP, Richard JP, Brandão TAS. The role of remote flavin adenine dinucleotide pieces in the oxidative decarboxylation catalyzed by salicylate hydroxylase. Bioorg Chem 2022; 119:105561. [PMID: 34965488 PMCID: PMC8824312 DOI: 10.1016/j.bioorg.2021.105561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 11/19/2021] [Accepted: 12/11/2021] [Indexed: 02/03/2023]
Abstract
Salicylate hydroxylase (NahG) has a single redox site in which FAD is reduced by NADH, the O2 is activated by the reduced flavin, and salicylate undergoes an oxidative decarboxylation by a C(4a)-hydroperoxyflavin intermediate to give catechol. We report experimental results that show the contribution of individual pieces of the FAD cofactor to the observed enzymatic activity for turnover of the whole cofactor. A comparison of the kinetic parameters and products for the NahG-catalyzed reactions of FMN and riboflavin cofactor fragments reveal that the adenosine monophosphate (AMP) and ribitol phosphate pieces of FAD act to anchor the flavin to the enzyme and to direct the partitioning of the C(4a)-hydroperoxyflavin reaction intermediate towards hydroxylation of salicylate. The addition of AMP or ribitol phosphate pieces to solutions of the truncated flavins results in a partial restoration of the enzymatic activity lost upon truncation of FAD, and the pieces direct the reaction of the C(4a)-hydroperoxyflavin intermediate towards hydroxylation of salicylate.
Collapse
Affiliation(s)
- Mozart S. Pereira
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Belo Horizonte, MG 31270-901, Brazil
| | - Simara S. de Araújo
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG 31270-901, Brazil
| | - Ronaldo A. P. Nagem
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG 31270-901, Brazil
| | - John P. Richard
- Department of Chemistry, University at Buffalo, SUNY, Buffalo, New York 14260-3000,CORRESPONDING AUTHOR: ;
| | - Tiago A. S. Brandão
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Belo Horizonte, MG 31270-901, Brazil.,CORRESPONDING AUTHOR: ;
| |
Collapse
|
8
|
Akkoyunlu B, Daly S, Casey E. Membrane bioreactors for the production of value-added products: Recent developments, challenges and perspectives. BIORESOURCE TECHNOLOGY 2021; 341:125793. [PMID: 34450442 DOI: 10.1016/j.biortech.2021.125793] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 08/10/2021] [Accepted: 08/13/2021] [Indexed: 06/13/2023]
Abstract
The potential of membrane bioreactors to produce value-added products such as biofuels, biopolymers, proteins, organic acids and lipids at high productivities is emerging. Despite the promising results at laboratory scale, industrial deployment of this technology is hindered due to challenges associated with scale-up. This review aims to address these challenges and create a framework to encourage further research directed towards industrial application of membrane bioreactors to produce value-added products. This review describes the current state-of-the art in such bioreactor systems by exploiting membranes to increase the mass transfer rate of the limiting substrates, reach high cell concentrations and separate the inhibitory substances that may inhibit the bioconversion reaction. It also covers the current trends in commercialization, challenges linked with membrane usage, such as high costs and membrane fouling, and proposes possible future directions for the wider application of membrane bioreactors.
Collapse
Affiliation(s)
- Burcu Akkoyunlu
- School of Chemical and Bioprocess Engineering, University College Dublin, Belfield, Dublin 4, Ireland; BiOrbic Bioeconomy SFI Research Centre, University College Dublin, Dublin, Ireland
| | - Sorcha Daly
- School of Chemical and Bioprocess Engineering, University College Dublin, Belfield, Dublin 4, Ireland; BiOrbic Bioeconomy SFI Research Centre, University College Dublin, Dublin, Ireland
| | - Eoin Casey
- School of Chemical and Bioprocess Engineering, University College Dublin, Belfield, Dublin 4, Ireland; BiOrbic Bioeconomy SFI Research Centre, University College Dublin, Dublin, Ireland.
| |
Collapse
|
9
|
Adebar N, Nastke A, Löwe J, Gröger H. Segmented Flow Processes to Overcome Hurdles of Whole-Cell Biocatalysis in the Presence of Organic Solvents. Angew Chem Int Ed Engl 2021; 60:15863-15869. [PMID: 33713367 PMCID: PMC8362180 DOI: 10.1002/anie.202015887] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 03/02/2021] [Indexed: 12/12/2022]
Abstract
In modern process development, it is imperative to consider biocatalysis, and whole‐cell catalysts often represent a favored form of such catalysts. However, the application of whole‐cell catalysis in typical organic batch two‐phase synthesis often struggles due to mass transfer limitations, emulsion formation, tedious work‐up and, thus, low yields. Herein, we demonstrate that utilizing segmented flow tools enables the conduction of whole‐cell biocatalysis efficiently in biphasic media. Exemplified for three different biotransformations, the power of such segmented flow processes is shown. For example, a 3‐fold increase of conversion from 34 % to >99 % and a dramatic simplified work‐up leading to a 1.5‐fold higher yield from 44 % to 65 % compared to the analogous batch process was achieved in such a flow process.
Collapse
Affiliation(s)
- Niklas Adebar
- Chair of Industrial Organic Chemistry and Biotechnology, Faculty of Chemistry, Bielefeld University, Universitätsstr. 25, 33615, Bielefeld, Germany
| | - Alina Nastke
- Chair of Industrial Organic Chemistry and Biotechnology, Faculty of Chemistry, Bielefeld University, Universitätsstr. 25, 33615, Bielefeld, Germany
| | - Jana Löwe
- Chair of Industrial Organic Chemistry and Biotechnology, Faculty of Chemistry, Bielefeld University, Universitätsstr. 25, 33615, Bielefeld, Germany
| | - Harald Gröger
- Chair of Industrial Organic Chemistry and Biotechnology, Faculty of Chemistry, Bielefeld University, Universitätsstr. 25, 33615, Bielefeld, Germany
| |
Collapse
|
10
|
Adebar N, Nastke A, Löwe J, Gröger H. Segmentierte Flow‐Prozesse zur Überwindung von Limitierungen der Ganzzell‐Biokatalyse in Gegenwart von organischen Lösungsmitteln. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202015887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Niklas Adebar
- Lehrstuhl für Industrielle Organische Chemie und Biotechnologie Fakultät der Chemie Universität Bielefeld Universitätsstr. 25 33615 Bielefeld Deutschland
| | - Alina Nastke
- Lehrstuhl für Industrielle Organische Chemie und Biotechnologie Fakultät der Chemie Universität Bielefeld Universitätsstr. 25 33615 Bielefeld Deutschland
| | - Jana Löwe
- Lehrstuhl für Industrielle Organische Chemie und Biotechnologie Fakultät der Chemie Universität Bielefeld Universitätsstr. 25 33615 Bielefeld Deutschland
| | - Harald Gröger
- Lehrstuhl für Industrielle Organische Chemie und Biotechnologie Fakultät der Chemie Universität Bielefeld Universitätsstr. 25 33615 Bielefeld Deutschland
| |
Collapse
|
11
|
Saravanan A, Senthil kumar P, Vo DVN, Jeevanantham S, Bhuvaneswari V, Anantha Narayanan V, Yaashikaa P, Swetha S, Reshma B. A comprehensive review on different approaches for CO2 utilization and conversion pathways. Chem Eng Sci 2021. [DOI: 10.1016/j.ces.2021.116515] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
12
|
Molina-Santiago C, de Vicente A, Romero D. Bacterial extracellular matrix as a natural source of biotechnologically multivalent materials. Comput Struct Biotechnol J 2021; 19:2796-2805. [PMID: 34093994 PMCID: PMC8138678 DOI: 10.1016/j.csbj.2021.05.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 04/29/2021] [Accepted: 05/02/2021] [Indexed: 12/15/2022] Open
Abstract
The extracellular matrix (ECM) is an intricate megastructure made by bacterial cells to form architecturally complex biostructures called biofilms. Protection of cells, modulation of cell-to-cell signalling, cell differentiation and environmental sensing are functions of the ECM that reflect its diverse chemical composition. Proteins, polysaccharides and eDNA have specific functionalities while cooperatively interacting to sustain the architecture and biological relevance of the ECM. The accumulated evidence on the chemical heterogeneity and specific functionalities of ECM components has attracted attention because of their potential biotechnological applications, from agriculture to the water and food industries. This review compiles information on the most relevant bacterial ECM components, the biophysical and chemical features responsible for their biological roles, and their potential to be further translated into biotechnological applications.
Collapse
Affiliation(s)
- Carlos Molina-Santiago
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Departamento de Microbiología, Universidad de Málaga, Bulevar Louis Pasteur 31 (Campus Universitario de teatinos), 29071 Málaga, Spain
| | - Antonio de Vicente
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Departamento de Microbiología, Universidad de Málaga, Bulevar Louis Pasteur 31 (Campus Universitario de teatinos), 29071 Málaga, Spain
| | - Diego Romero
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Departamento de Microbiología, Universidad de Málaga, Bulevar Louis Pasteur 31 (Campus Universitario de teatinos), 29071 Málaga, Spain
| |
Collapse
|
13
|
Heuschkel I, Hanisch S, Volke DC, Löfgren E, Hoschek A, Nikel PI, Karande R, Bühler K. Pseudomonas taiwanensis biofilms for continuous conversion of cyclohexanone in drip flow and rotating bed reactors. Eng Life Sci 2021; 21:258-269. [PMID: 33716623 PMCID: PMC7923564 DOI: 10.1002/elsc.202000072] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 12/15/2020] [Accepted: 12/16/2020] [Indexed: 12/25/2022] Open
Abstract
In this study, the biocatalytic performance of a Baeyer-Villiger monooxygenase (BVMO) catalyzing the reaction of cyclohexanone to ε-caprolactone was investigated in Pseudomonas biofilms. Biofilm growth and development of two Pseudomonas taiwanensis VLB120 variants, Ps_BVMO and Ps_BVMO_DGC, were evaluated in drip flow reactors (DFRs) and rotating bed reactors (RBRs). Engineering a hyperactive diguanylate cyclase (DGC) from Caulobacter crescentus into Ps_BVMO resulted in faster biofilm growth compared to the control Ps_BVMO strain in the DFRs. The maximum product formation rates of 92 and 87 g m-2 d-1 were observed for mature Ps_BVMO and Ps_ BVMO_DGC biofilms, respectively. The application of the engineered variants in the RBR was challenged by low biofilm surface coverage (50-60%) of rotating bed cassettes, side-products formation, oxygen limitation, and a severe drop in production rates with time. By implementing an active oxygen supply mode and a twin capillary spray feed, the biofilm surface coverage was maximized to 70-80%. BVMO activity was severely inhibited by cyclohexanol formation, resulting in a decrease in product formation rates. By controlling the cyclohexanone feed concentration at 4 mM, a stable product formation rate of 14 g m-2 d-1 and a substrate conversion of 60% was achieved in the RBR.
Collapse
Affiliation(s)
- Ingeborg Heuschkel
- Department of Solar MaterialsHelmholtz‐Centre for Environmental ResearchLeipzigGermany
| | - Selina Hanisch
- Department of Solar MaterialsHelmholtz‐Centre for Environmental ResearchLeipzigGermany
- ZINT ‐ Zentrum für integrierte NaturstofftechnikTU DresdenDresdenGermany
| | - Daniel C. Volke
- The Novo Nordisk Foundation Center for BiosustainabilityTechnical University of DenmarkLyngbyDenmark
| | | | - Anna Hoschek
- Department of Solar MaterialsHelmholtz‐Centre for Environmental ResearchLeipzigGermany
| | - Pablo I. Nikel
- The Novo Nordisk Foundation Center for BiosustainabilityTechnical University of DenmarkLyngbyDenmark
| | - Rohan Karande
- Department of Solar MaterialsHelmholtz‐Centre for Environmental ResearchLeipzigGermany
| | - Katja Bühler
- Department of Solar MaterialsHelmholtz‐Centre for Environmental ResearchLeipzigGermany
- ZINT ‐ Zentrum für integrierte NaturstofftechnikTU DresdenDresdenGermany
| |
Collapse
|
14
|
Formation and characterization of biofilms formed by salt-tolerant yeast strains in seawater-based growth medium. Appl Microbiol Biotechnol 2021; 105:2411-2426. [PMID: 33630153 DOI: 10.1007/s00253-021-11132-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 12/30/2020] [Accepted: 01/20/2021] [Indexed: 10/22/2022]
Abstract
Yeast whole cells have been widely used in modern biotechnology as biocatalysts to generate numerous compounds of industrial, chemical, and pharmaceutical importance. Since many of the biocatalysis-utilizing manufactures have become more concerned about environmental issues, seawater is now considered a sustainable alternative to freshwater for biocatalytic processes. This approach plausibly commenced new research initiatives into exploration of salt-tolerant yeast strains. Recently, there has also been a growing interest in possible applications of microbial biofilms in the field of biocatalysis. In these complex communities, cells demonstrate higher resistance to adverse environmental conditions due to their embedment in an extracellular matrix, in which physical, chemical, and physiological gradients exist. Considering these two topics, seawater and biofilms, in this work, we characterized biofilm formation in seawater-based growth media by several salt-tolerant yeast strains with previously demonstrated biocatalytic capacities. The tested strains formed both air-liquid-like biofilms and biofilms on silicone surfaces, with Debaryomyces fabryi, Schwanniomyces etchellsii, Schwanniomyces polymorphus, and Kluyveromyces marxianus showing the highest biofilm formation. The extracted biofilm extracellular matrices mostly consisted of carbohydrates and proteins. The latter group was primarily represented by enzymes involved in metabolic processes, particularly the biosynthetic ones, and in the response to stimuli. Specific features were also found in the carbohydrate composition of the extracellular matrix, which were dependent both on the yeast isolate and the nature of formed biofilms. Overall, our findings presented herein provide a unique data resource for further development and optimization of biocatalytic processes and applications employing seawater and halotolerant yeast biofilms.Key points• Ability for biofilm formation of some yeast-halotolerant strains in seawater medium• ECM composition dependent on strain and biofilm-forming surface• Metabolic enzymes in the ECM with potential applications for biocatalysis.
Collapse
|
15
|
Abstract
Recent years have witnessed a growing interest in the use of biocatalysts in flow reactors. This merging combines the high selectivity and mild operation conditions typical of biocatalysis with enhanced mass transfer and resource efficiency associated to flow chemistry. Additionally, it provides a sound environment to emulate Nature by mimicking metabolic pathways in living cells and to produce goods through the systematic organization of enzymes towards efficient cascade reactions. Moreover, by enabling the combination of enzymes from different hosts, this approach paves the way for novel pathways. The present review aims to present recent developments within the scope of flow chemistry involving multi-enzymatic cascade reactions. The types of reactors used are briefly addressed. Immobilization methodologies and strategies for the application of the immobilized biocatalysts are presented and discussed. Key aspects related to the use of whole cells in flow chemistry are presented. The combination of chemocatalysis and biocatalysis is also addressed and relevant aspects are highlighted. Challenges faced in the transition from microscale to industrial scale are presented and discussed.
Collapse
|
16
|
Adebar N, Nastke A, Gröger H. Concepts for flow chemistry with whole-cell biocatalysts. REACT CHEM ENG 2021. [DOI: 10.1039/d0re00331j] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
By combining continuous flow processing and biocatalysis, efficient, stable and cost-effective processes can be realised. In this review, an overview about different concepts for continuous flow processes based on the use of whole-cells as catalysts is given.
Collapse
Affiliation(s)
- Niklas Adebar
- Chair of Industrial Organic Chemistry and Biotechnology
- Faculty of Chemistry
- Bielefeld University
- 33615 Bielefeld
- Germany
| | - Alina Nastke
- Chair of Industrial Organic Chemistry and Biotechnology
- Faculty of Chemistry
- Bielefeld University
- 33615 Bielefeld
- Germany
| | - Harald Gröger
- Chair of Industrial Organic Chemistry and Biotechnology
- Faculty of Chemistry
- Bielefeld University
- 33615 Bielefeld
- Germany
| |
Collapse
|
17
|
Biofilm reactors for value-added products production: An in-depth review. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2020. [DOI: 10.1016/j.bcab.2020.101662] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
|
18
|
Hu Y, Liu X, Ren ATM, Gu JD, Cao B. Optogenetic Modulation of a Catalytic Biofilm for the Biotransformation of Indole into Tryptophan. CHEMSUSCHEM 2019; 12:5142-5148. [PMID: 31621183 DOI: 10.1002/cssc.201902413] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 10/15/2019] [Indexed: 06/10/2023]
Abstract
In green chemical synthesis, biofilms as biocatalysts have shown great promise. Efficient biofilm-mediated biocatalysis requires the modulation of biofilm formation. Optogenetic tools are ideal to control biofilms because light is noninvasive, easily controllable, and cost-efficient. In this study, a gene circuit responsive to near-infrared (NIR) light was used to modulate the cellular level of bis-(3'-5') cyclic dimeric guanosine monophosphate (c-di-GMP), a central regulator of the prokaryote biofilm lifestyle, which allowed the regulation of biofilm formation by using NIR light. The engineered biofilm was applied to catalyze the biotransformation of indole into tryptophan in submerged biofilm reactors and NIR-light-enhanced biofilm formation resulted in an approximately 30 % increase in tryptophan yield, which demonstrates the feasibility of the application of light to modulate the formation and performance of catalytic biofilms for chemical production. The c-di-GMP-targeted optogenetic approach to modulate catalytic biofilms showcases applications for biofilm-mediated biocatalysis.
Collapse
Affiliation(s)
- Yidan Hu
- Singapore Centre for Environmental Life Sciences Engineering, Interdisciplinary Graduate School, Nanyang Technological University, 60 Nanyang Dr, Singapore, 637551, Singapore
| | - Xiaobo Liu
- Singapore Centre for Environmental Life Sciences Engineering, Interdisciplinary Graduate School, Nanyang Technological University, 60 Nanyang Dr, Singapore, 637551, Singapore
- Laboratory of Environmental Microbiology and Toxicology, School of Biological Sciences, The University of Hong Kong, Hong Kong, P.R. China
| | - Aloysius Teng Min Ren
- Singapore Centre for Environmental Life Sciences Engineering, Interdisciplinary Graduate School, Nanyang Technological University, 60 Nanyang Dr, Singapore, 637551, Singapore
| | - Ji-Dong Gu
- Laboratory of Environmental Microbiology and Toxicology, School of Biological Sciences, The University of Hong Kong, Hong Kong, P.R. China
| | - Bin Cao
- Singapore Centre for Environmental Life Sciences Engineering, Interdisciplinary Graduate School, Nanyang Technological University, 60 Nanyang Dr, Singapore, 637551, Singapore
- School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Ave, Singapore, 639798, Singapore
| |
Collapse
|
19
|
Wynands B, Otto M, Runge N, Preckel S, Polen T, Blank LM, Wierckx N. Streamlined Pseudomonas taiwanensis VLB120 Chassis Strains with Improved Bioprocess Features. ACS Synth Biol 2019; 8:2036-2050. [PMID: 31465206 DOI: 10.1021/acssynbio.9b00108] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Microbes harbor many traits that are dispensable or even unfavorable under industrial and laboratory settings. The elimination of such traits could improve the host's efficiency, genetic stability, and robustness, thereby increasing the predictability and boosting its performance as a microbial cell factory. We engineered solvent-tolerant Pseudomonas taiwanensis VLB120 to yield streamlined chassis strains with higher growth rates and biomass yields, enhanced solvent tolerance, and improved process performance. In total, the genome was reduced by up to 10%. This was achieved by the elimination of genes that enable the cell to swim and form biofilms and by the deletion of the megaplasmid pSTY and large proviral segments. The resulting strain GRC1 had a 15% higher growth rate and biomass yield than the wildtype. However, this strain lacks the pSTY-encoded efflux pump TtgGHI, rendering it solvent-sensitive. Through reintegration of ttgGHI by chromosomal insertion without (GRC2) and with (GRC3) the corresponding regulator genes, the solvent-tolerant phenotype was enhanced. The generated P. taiwanensis GRC strains enlarge the repertoire of streamlined chassis with enhanced key performance indicators, making them attractive hosts for biotechnological applications. The different solvent tolerance levels of GRC1, GRC2, and GRC3 enable the selection of a fitting host platform in relation to the desired process requirements in a chassis à la carte principle. This was demonstrated in a metabolic engineering approach for the production of phenol from glycerol. The streamlined producer GRC1Δ5-TPL38 outperformed the equivalent nonstreamlined producer VLB120Δ5-TPL38 concerning phenol titer, rate, and yield, thereby highlighting the added value of the streamlined chassis.
Collapse
Affiliation(s)
- Benedikt Wynands
- Institute of Applied Microbiology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Maike Otto
- Institute of Applied Microbiology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Nadine Runge
- Institute of Applied Microbiology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
| | - Sarah Preckel
- Institute of Applied Microbiology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
| | - Tino Polen
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Lars M. Blank
- Institute of Applied Microbiology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
| | - Nick Wierckx
- Institute of Applied Microbiology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| |
Collapse
|
20
|
Dong J, Fernández‐Fueyo E, Hollmann F, Paul CE, Pesic M, Schmidt S, Wang Y, Younes S, Zhang W. Biocatalytic Oxidation Reactions: A Chemist's Perspective. Angew Chem Int Ed Engl 2018; 57:9238-9261. [PMID: 29573076 PMCID: PMC6099261 DOI: 10.1002/anie.201800343] [Citation(s) in RCA: 271] [Impact Index Per Article: 45.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Indexed: 01/25/2023]
Abstract
Oxidation chemistry using enzymes is approaching maturity and practical applicability in organic synthesis. Oxidoreductases (enzymes catalysing redox reactions) enable chemists to perform highly selective and efficient transformations ranging from simple alcohol oxidations to stereoselective halogenations of non-activated C-H bonds. For many of these reactions, no "classical" chemical counterpart is known. Hence oxidoreductases open up shorter synthesis routes based on a more direct access to the target products. The generally very mild reaction conditions may also reduce the environmental impact of biocatalytic reactions compared to classical counterparts. In this Review, we critically summarise the most important recent developments in the field of biocatalytic oxidation chemistry and identify the most pressing bottlenecks as well as promising solutions.
Collapse
Affiliation(s)
- JiaJia Dong
- Department of BiotechnologyDelft University of Technologyvan der Maasweg 92629HZDelftThe Netherlands
| | - Elena Fernández‐Fueyo
- Department of BiotechnologyDelft University of Technologyvan der Maasweg 92629HZDelftThe Netherlands
| | - Frank Hollmann
- Department of BiotechnologyDelft University of Technologyvan der Maasweg 92629HZDelftThe Netherlands
| | - Caroline E. Paul
- Department of BiotechnologyDelft University of Technologyvan der Maasweg 92629HZDelftThe Netherlands
| | - Milja Pesic
- Department of BiotechnologyDelft University of Technologyvan der Maasweg 92629HZDelftThe Netherlands
| | - Sandy Schmidt
- Department of BiotechnologyDelft University of Technologyvan der Maasweg 92629HZDelftThe Netherlands
| | - Yonghua Wang
- School of Food Science and EngineeringSouth China University of TechnologyGuangzhou510640P. R. China
| | - Sabry Younes
- Department of BiotechnologyDelft University of Technologyvan der Maasweg 92629HZDelftThe Netherlands
| | - Wuyuan Zhang
- Department of BiotechnologyDelft University of Technologyvan der Maasweg 92629HZDelftThe Netherlands
| |
Collapse
|
21
|
Dong J, Fernández-Fueyo E, Hollmann F, Paul CE, Pesic M, Schmidt S, Wang Y, Younes S, Zhang W. Biokatalytische Oxidationsreaktionen - aus der Sicht eines Chemikers. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201800343] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- JiaJia Dong
- Department of Biotechnology; Delft University of Technology; van der Maasweg 9 2629HZ Delft Niederlande
| | - Elena Fernández-Fueyo
- Department of Biotechnology; Delft University of Technology; van der Maasweg 9 2629HZ Delft Niederlande
| | - Frank Hollmann
- Department of Biotechnology; Delft University of Technology; van der Maasweg 9 2629HZ Delft Niederlande
| | - Caroline E. Paul
- Department of Biotechnology; Delft University of Technology; van der Maasweg 9 2629HZ Delft Niederlande
| | - Milja Pesic
- Department of Biotechnology; Delft University of Technology; van der Maasweg 9 2629HZ Delft Niederlande
| | - Sandy Schmidt
- Department of Biotechnology; Delft University of Technology; van der Maasweg 9 2629HZ Delft Niederlande
| | - Yonghua Wang
- School of Food Science and Engineering; South China University of Technology; Guangzhou 510640 P. R. China
| | - Sabry Younes
- Department of Biotechnology; Delft University of Technology; van der Maasweg 9 2629HZ Delft Niederlande
| | - Wuyuan Zhang
- Department of Biotechnology; Delft University of Technology; van der Maasweg 9 2629HZ Delft Niederlande
| |
Collapse
|
22
|
Wynands B, Lenzen C, Otto M, Koch F, Blank LM, Wierckx N. Metabolic engineering of Pseudomonas taiwanensis VLB120 with minimal genomic modifications for high-yield phenol production. Metab Eng 2018; 47:121-133. [PMID: 29548982 DOI: 10.1016/j.ymben.2018.03.011] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 03/07/2018] [Accepted: 03/11/2018] [Indexed: 12/31/2022]
Abstract
Aromatic chemicals are important building blocks for the production of a multitude of everyday commodities. Currently, aromatics production relies almost exclusively on petrochemical processes. To achieve sustainability, alternative synthesis methods need to be developed. Here, we strived for an efficient production of phenol, a model aromatic compound of industrial relevance, from renewable carbon sources using the solvent-tolerant biocatalyst Pseudomonas taiwanensis VLB120. First, multiple catabolic routes for the degradation of aromatics and related compounds were inactivated, thereby obtaining the chassis strain P. taiwanensis VLB120Δ5 incapable of growing on 4-hydroxybenzoate (ΔpobA), tyrosine (Δhpd), and quinate (ΔquiC, ΔquiC1, ΔquiC2). In this context, a novel gene contributing to the quinate catabolism was identified (quiC2). Second, we employed a combination of reverse- and forward engineering to increase metabolic flux towards the product, using leads obtained from the analysis of aromatics producing Pseudomonas putida strains previously generated by mutagenesis. Phenol production was enabled by the heterologous expression of a codon-optimized and chromosomally integrated tyrosine phenol-lyase encoding gene from Pantoea agglomerans AJ2985 (PaTPL2). The genomic modification of endogenous genes encoding TrpEP290S, AroF-1P148L, and PheAT310I, and the deletion of pykA improved phenol production 17-fold, while also minimizing the burden caused by plasmids and auxotrophies. The additional overexpression of known bottleneck enzymes (AroGfbr, TyrAfbr) derived from Escherichia coli further enhanced phenol titers. The best producing strain P. taiwanensis VLB120Δ5-TPL36 reached yields of 15.8% and 18.5% (Cmol/Cmol) phenol from glucose and glycerol, respectively, in a mineral medium without addition of complex nutrients. This is the highest yield ever reported for microbially produced phenol.
Collapse
Affiliation(s)
- Benedikt Wynands
- Institute of Applied Microbiology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
| | - Christoph Lenzen
- Institute of Applied Microbiology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
| | - Maike Otto
- Institute of Applied Microbiology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
| | - Falk Koch
- Institute of Applied Microbiology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
| | - Lars M Blank
- Institute of Applied Microbiology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
| | - Nick Wierckx
- Institute of Applied Microbiology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany.
| |
Collapse
|
23
|
Polakovič M, Švitel J, Bučko M, Filip J, Neděla V, Ansorge-Schumacher MB, Gemeiner P. Progress in biocatalysis with immobilized viable whole cells: systems development, reaction engineering and applications. Biotechnol Lett 2017; 39:667-683. [PMID: 28181062 DOI: 10.1007/s10529-017-2300-y] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 02/01/2017] [Indexed: 11/28/2022]
Abstract
Viable microbial cells are important biocatalysts in the production of fine chemicals and biofuels, in environmental applications and also in emerging applications such as biosensors or medicine. Their increasing significance is driven mainly by the intensive development of high performance recombinant strains supplying multienzyme cascade reaction pathways, and by advances in preservation of the native state and stability of whole-cell biocatalysts throughout their application. In many cases, the stability and performance of whole-cell biocatalysts can be highly improved by controlled immobilization techniques. This review summarizes the current progress in the development of immobilized whole-cell biocatalysts, the immobilization methods as well as in the bioreaction engineering aspects and economical aspects of their biocatalytic applications.
Collapse
Affiliation(s)
- Milan Polakovič
- Institute of Chemical and Environmental Engineering, Faculty of Chemical and Food Technology, Slovak Technical University, Bratislava, Slovakia
| | - Juraj Švitel
- Institute of Chemical and Environmental Engineering, Faculty of Chemical and Food Technology, Slovak Technical University, Bratislava, Slovakia
| | - Marek Bučko
- Department of Glycobiotechnology, Institute of Chemistry, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Jaroslav Filip
- Center for Advanced Materials, Qatar University, Doha, Qatar
| | - Vilém Neděla
- Institute of Scientific Instruments, Academy of Sciences Czech Republic, Brno, Czech Republic
| | | | - Peter Gemeiner
- Department of Glycobiotechnology, Institute of Chemistry, Slovak Academy of Sciences, Bratislava, Slovakia.
| |
Collapse
|
24
|
Terrestrial Microalgae: Novel Concepts for Biotechnology and Applications. PROGRESS IN BOTANY VOL. 79 2017. [DOI: 10.1007/124_2017_10] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
|
25
|
Tong X, Barberi TT, Botting CH, Sharma SV, Simmons MJH, Overton TW, Goss RJM. Rapid enzyme regeneration results in the striking catalytic longevity of an engineered, single species, biocatalytic biofilm. Microb Cell Fact 2016; 15:180. [PMID: 27769259 PMCID: PMC5073922 DOI: 10.1186/s12934-016-0579-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 10/14/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Engineering of single-species biofilms for enzymatic generation of fine chemicals is attractive. We have recently demonstrated the utility of an engineered Escherichia coli biofilm as a platform for synthesis of 5-halotryptophan. E. coli PHL644, expressing a recombinant tryptophan synthase, was employed to generate a biofilm. Its rapid deposition, and instigation of biofilm formation, was enforced by employing a spin-down method. The biofilm presents a large three-dimensional surface area, excellent for biocatalysis. The catalytic longevity of the engineered biofilm is striking, and we had postulated that this was likely to largely result from protection conferred to recombinant enzymes by biofilm's extracellular matrix. SILAC (stable isotopic labelled amino acids in cell cultures), and in particular dynamic SILAC, in which pulses of different isotopically labelled amino acids are administered to cells over a time course, has been used to follow the fate of proteins. To explore within our spin coated biofilm, whether the recombinant enzyme's longevity might be in part due to its regeneration, we introduced pulses of isotopically labelled lysine and phenylalanine into medium overlaying the biofilm and followed their incorporation over the course of biofilm development. RESULTS Through SILAC analysis, we reveal that constant and complete regeneration of recombinant enzymes occurs within spin coated biofilms. The striking catalytic longevity within the biofilm results from more than just simple protection of active enzyme by the biofilm and its associated extracellular matrix. The replenishment of recombinant enzyme is likely to contribute significantly to the catalytic longevity observed for the engineered biofilm system. CONCLUSIONS Here we provide the first evidence of a recombinant enzyme's regeneration in an engineered biofilm. The recombinant enzyme was constantly replenished over time as evidenced by dynamic SILAC, which suggests that the engineered E. coli biofilms are highly metabolically active, having a not inconsiderable energetic demand. The constant renewal of recombinant enzyme highlights the attractive possibility of utilising this biofilm system as a dynamic platform into which enzymes of interest can be introduced in a "plug-and-play" fashion and potentially be controlled through promoter switching for production of a series of desired fine chemicals.
Collapse
Affiliation(s)
- Xiaoxue Tong
- School of Chemistry, University of St. Andrews, St. Andrews, KY16 9ST, UK.,Biomedical Sciences Research Complex, University of St. Andrews, St. Andrews, KY16 9ST, UK
| | - Tania Triscari Barberi
- School of Chemistry, University of St. Andrews, St. Andrews, KY16 9ST, UK.,Biomedical Sciences Research Complex, University of St. Andrews, St. Andrews, KY16 9ST, UK
| | - Catherine H Botting
- Biomedical Sciences Research Complex, University of St. Andrews, St. Andrews, KY16 9ST, UK
| | - Sunil V Sharma
- School of Chemistry, University of St. Andrews, St. Andrews, KY16 9ST, UK.,Biomedical Sciences Research Complex, University of St. Andrews, St. Andrews, KY16 9ST, UK
| | - Mark J H Simmons
- School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham, B152TT, UK
| | - Tim W Overton
- School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham, B152TT, UK
| | - Rebecca J M Goss
- School of Chemistry, University of St. Andrews, St. Andrews, KY16 9ST, UK. .,Biomedical Sciences Research Complex, University of St. Andrews, St. Andrews, KY16 9ST, UK.
| |
Collapse
|
26
|
Halan B, Vassilev I, Lang K, Schmid A, Buehler K. Growth of Pseudomonas taiwanensis VLB120∆C biofilms in the presence of n-butanol. Microb Biotechnol 2016; 10:745-755. [PMID: 27696696 PMCID: PMC5481524 DOI: 10.1111/1751-7915.12413] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 08/25/2016] [Accepted: 08/31/2016] [Indexed: 12/28/2022] Open
Abstract
Biocatalytic processes often encounter problems due to toxic reactants and products, which reduce biocatalyst viability. Thus, robust organisms capable of tolerating or adapting towards such compounds are of high importance. This study systematically investigated the physiological response of Pseudomonas taiwanensisVLB120∆C biofilms when exposed to n‐butanol, one of the potential next generation biofuels as well as a toxic substance using microscopic and biochemical methods. Initially P. taiwanensisVLB120∆C biofilms did not show any observable growth in the presence of 3% butanol. Prolonged cultivation of 10 days led to biofilm adaptation, glucose and oxygen uptake doubled and consequently it was possible to quantify biomass. Complementing the medium with yeast extract and presumably reducing the metabolic burden caused by butanol exposure further increased the biomass yield. In course of cultivation cells reduced their size in the presence of n‐butanol which results in an enlarged surface‐to‐volume ratio and thus increased nutrient uptake. Finally, biofilm enhanced its extracellular polymeric substances (EPS) production when exposed to n‐butanol. The predominant response of these biofilms under n‐butanol stress are higher energy demand, increased biomass yield upon medium complements, larger surface‐to‐volume ratio and enhanced EPS production. Although we observed a distinct increase in biomass in the presence of 3% butanol it was not possible to cultivate P. taiwanensisVLB120∆C biofilms at higher n‐butanol concentrations. Thereby this study shows that biofilms are not per se tolerant against solvents, and need to adapt to toxic n‐butanol concentrations.
Collapse
Affiliation(s)
- Babu Halan
- Department of Solar Materials, Helmholtz-Centre for Environmental Research - UFZ GmbH, Permoserstraße 15, 04318, Leipzig, Germany
| | - Igor Vassilev
- Laboratory of Chemical Biotechnology, Department of Biochemical and Chemical Engineering, TU Dortmund University, Emil-Figge-Str. 66, 44227, Dortmund, Germany
| | - Karsten Lang
- Laboratory of Chemical Biotechnology, Department of Biochemical and Chemical Engineering, TU Dortmund University, Emil-Figge-Str. 66, 44227, Dortmund, Germany
| | - Andreas Schmid
- Department of Solar Materials, Helmholtz-Centre for Environmental Research - UFZ GmbH, Permoserstraße 15, 04318, Leipzig, Germany
| | - Katja Buehler
- Department of Solar Materials, Helmholtz-Centre for Environmental Research - UFZ GmbH, Permoserstraße 15, 04318, Leipzig, Germany
| |
Collapse
|
27
|
Willrodt C, Halan B, Karthaus L, Rehdorf J, Julsing MK, Buehler K, Schmid A. Continuous multistep synthesis of perillic acid from limonene by catalytic biofilms under segmented flow. Biotechnol Bioeng 2016; 114:281-290. [DOI: 10.1002/bit.26071] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 07/25/2016] [Accepted: 08/01/2016] [Indexed: 02/06/2023]
Affiliation(s)
- Christian Willrodt
- Department of Solar Materials; Helmholtz Centre for Environmental Research (UFZ); Permoserstrasse 15 04318 Leipzig Germany
| | - Babu Halan
- Department of Solar Materials; Helmholtz Centre for Environmental Research (UFZ); Permoserstrasse 15 04318 Leipzig Germany
| | - Lisa Karthaus
- Department of Biochemical and Chemical Engineering; Laboratory of Chemical Biotechnology; TU Dortmund University; Dortmund Germany
| | | | - Mattijs K. Julsing
- Department of Biochemical and Chemical Engineering; Laboratory of Chemical Biotechnology; TU Dortmund University; Dortmund Germany
| | - Katja Buehler
- Department of Solar Materials; Helmholtz Centre for Environmental Research (UFZ); Permoserstrasse 15 04318 Leipzig Germany
| | - Andreas Schmid
- Department of Solar Materials; Helmholtz Centre for Environmental Research (UFZ); Permoserstrasse 15 04318 Leipzig Germany
| |
Collapse
|
28
|
Soussan L, Pen N, Belleville MP, Marcano JS, Paolucci-Jeanjean D. Alkane biohydroxylation: Interests, constraints and future developments. J Biotechnol 2016; 222:117-42. [DOI: 10.1016/j.jbiotec.2016.02.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Revised: 01/17/2016] [Accepted: 02/02/2016] [Indexed: 01/07/2023]
|
29
|
Kremer F, Blank LM, Jones PR, Akhtar MK. A Comparison of the Microbial Production and Combustion Characteristics of Three Alcohol Biofuels: Ethanol, 1-Butanol, and 1-Octanol. Front Bioeng Biotechnol 2015; 3:112. [PMID: 26301219 PMCID: PMC4526805 DOI: 10.3389/fbioe.2015.00112] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2015] [Accepted: 07/21/2015] [Indexed: 11/13/2022] Open
Abstract
Over the last decade, microbes have been engineered for the manufacture of a variety of biofuels. Saturated linear-chain alcohols have great potential as transport biofuels. Their hydrocarbon backbones, as well as oxygenated content, confer combustive properties that make it suitable for use in internal combustion engines. Herein, we compared the microbial production and combustion characteristics of ethanol, 1-butanol, and 1-octanol. In terms of productivity and efficiency, current microbial platforms favor the production of ethanol. From a combustion standpoint, the most suitable fuel for spark-ignition engines would be ethanol, while for compression-ignition engines it would be 1-octanol. However, any general conclusions drawn at this stage regarding the most superior biofuel would be premature, as there are still many areas that need to be addressed, such as large-scale purification and pipeline compatibility. So far, the difficulties in developing and optimizing microbial platforms for fuel production, particularly for newer fuel candidates, stem from our poor understanding of the myriad biological factors underpinning them. A great deal of attention therefore needs to be given to the fundamental mechanisms that govern biological processes. Additionally, research needs to be undertaken across a wide range of disciplines to overcome issues of sustainability and commercial viability.
Collapse
Affiliation(s)
- Florian Kremer
- Institute for Combustion Engines (VKA), RWTH Aachen University , Aachen , Germany
| | - Lars M Blank
- Aachen Biology and Biotechnology (ABBt), Institute of Applied Microbiology (iAMB), RWTH Aachen University , Aachen , Germany
| | - Patrik R Jones
- Department of Life Sciences, Imperial College London , London , UK
| | - M Kalim Akhtar
- Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh , Edinburgh , UK
| |
Collapse
|
30
|
Holtmann D, Fraaije MW, Arends IWCE, Opperman DJ, Hollmann F. The taming of oxygen: biocatalytic oxyfunctionalisations. Chem Commun (Camb) 2015; 50:13180-200. [PMID: 24902635 DOI: 10.1039/c3cc49747j] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The scope and limitations of oxygenases as catalysts for preparative organic synthesis is discussed.
Collapse
Affiliation(s)
- Dirk Holtmann
- DECHEMA Research Institute, Theodor-Heuss-Allee 25, 60486 Frankfurt am Main, Germany
| | | | | | | | | |
Collapse
|
31
|
Al-Kaidy H, Duwe A, Huster M, Muffler K, Schlegel C, Sieker T, Stadtmüller R, Tippkötter N, Ulber R. Biotechnology and Bioprocess Engineering - From the First Ullmann's Article to Recent Trends. CHEMBIOENG REVIEWS 2015. [DOI: 10.1002/cben.201500008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
|
32
|
Lang K, Buehler K, Schmid A. Multistep Synthesis of (S)-3-Hydroxyisobutyric Acid from Glucose usingPseudomonas taiwanensisVLB120 B83 T7 Catalytic Biofilms. Adv Synth Catal 2015. [DOI: 10.1002/adsc.201500205] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
33
|
Stabilization of single species Synechocystis biofilms by cultivation under segmented flow. J Ind Microbiol Biotechnol 2015; 42:1083-9. [PMID: 25948048 DOI: 10.1007/s10295-015-1626-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 04/25/2015] [Indexed: 12/18/2022]
Abstract
The application of segmented flow on a Synechocystis sp. PCC 6803 biofilm prevented excessive biomass formation and clogging by fundamentally changing the structure of the microbial community. It was possible to continuously operate a capillary microreactor for 5 weeks, before the experiment was actively terminated. The biofilm developed up to a thickness of 70-120 µm. Surprisingly, the biofilm stopped growing at this thickness and stayed constant without any detachment events occurring afterwards. The substrates CO2 and light were supplied in a counter-current fashion. Confocal microscopy revealed a throughout photosynthetically active biofilm, indicated by the red fluorescence of photo pigments. This control concept and biofilm reaction setup may enable continuous light driven synthesis of value added compounds in future.
Collapse
|
34
|
Muschiol J, Peters C, Oberleitner N, Mihovilovic MD, Bornscheuer UT, Rudroff F. Cascade catalysis – strategies and challenges en route to preparative synthetic biology. Chem Commun (Camb) 2015; 51:5798-811. [DOI: 10.1039/c4cc08752f] [Citation(s) in RCA: 251] [Impact Index Per Article: 27.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
In this feature article recent progress and future perspectives of cascade catalysis combining bio/bio or bio/chemo catalysts are presented.
Collapse
Affiliation(s)
- Jan Muschiol
- Institute of Biochemistry
- Dept. of Biotechnology & Enzyme Catalysis
- Greifswald University
- 17489 Greifswald
- Germany
| | - Christin Peters
- Institute of Biochemistry
- Dept. of Biotechnology & Enzyme Catalysis
- Greifswald University
- 17489 Greifswald
- Germany
| | - Nikolin Oberleitner
- Institute of Applied Synthetic Chemistry
- Vienna University of Technology
- 1060 Vienna
- Austria
| | - Marko D. Mihovilovic
- Institute of Applied Synthetic Chemistry
- Vienna University of Technology
- 1060 Vienna
- Austria
| | - Uwe T. Bornscheuer
- Institute of Biochemistry
- Dept. of Biotechnology & Enzyme Catalysis
- Greifswald University
- 17489 Greifswald
- Germany
| | - Florian Rudroff
- Institute of Applied Synthetic Chemistry
- Vienna University of Technology
- 1060 Vienna
- Austria
| |
Collapse
|
35
|
Al-Kaidy H, Duwe A, Huster M, Muffler K, Schlegel C, Sieker T, Stadtmüller R, Tippkötter N, Ulber R. Biotechnologie und Bioverfahrenstechnik - Vom ersten Ullmanns Artikel bis hin zu aktuellen Forschungsthemen. CHEM-ING-TECH 2014. [DOI: 10.1002/cite.201400083] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
|
36
|
Halan B, Letzel T, Schmid A, Buehler K. Solid support membrane-aerated catalytic biofilm reactor for the continuous synthesis of (S)-styrene oxide at gram scale. Biotechnol J 2014; 9:1339-49. [DOI: 10.1002/biot.201400341] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 07/27/2014] [Accepted: 08/07/2014] [Indexed: 11/09/2022]
|
37
|
|
38
|
Isolation and characterization of a thermotolerant ene reductase from Geobacillus sp. 30 and its heterologous expression in Rhodococcus opacus. Appl Microbiol Biotechnol 2014; 98:5925-35. [PMID: 24927695 DOI: 10.1007/s00253-014-5668-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Revised: 03/04/2014] [Accepted: 03/05/2014] [Indexed: 01/04/2023]
Abstract
Rhodococcus opacus B-4 cells are adhesive to and even dispersible in water-immiscible hydrocarbons owing to their highly lipophilic nature. In this study, we focused on the high operational stability of thermophilic enzymes and applied them to a biocatalytic conversion in an organic reaction medium using R. opacus B-4 as a lipophilic capsule of enzymes to deliver them into the organic medium. A novel thermo- and organic-solvent-tolerant ene reductase, which can catalyze the enantioselective reduction of ketoisophorone to (6R)-levodione, was isolated from Geobacillus sp. 30, and the gene encoding the enzyme was heterologously expressed in R. opacus B-4. Another thermophilic enzyme which catalyzes NAD(+)-dependent dehydrogenation of cyclohexanol was identified from the gene-expression library of Thermus thermophilus and the gene was coexpressed in R. opacus B-4 for cofactor regeneration. While the recombinant cells were not viable in the mixture due to high reaction temperature, 634 mM of (6R)-levodione could be produced with an enantiopurity of 89.2 % ee by directly mixing the wet cells of the recombinant R. opacus with a mixture of ketoisophorone and cyclohexanol at 50 °C. The conversion rate observed with the heat-killed recombinant cells was considerably higher than that obtained with a cell-free enzyme solution, demonstrating that the accessibility between the substrates and enzymes could be improved by employing R. opacus cells as a lipophilic enzyme capsule. These results imply that a combination of thermophilic enzymes and lipophilic cells can be a promising approach for the biocatalytic production of water-insoluble chemicals.
Collapse
|
39
|
Metabolic engineering of Pseudomonas sp. strain VLB120 as platform biocatalyst for the production of isobutyric acid and other secondary metabolites. Microb Cell Fact 2014; 13:2. [PMID: 24397404 PMCID: PMC3897908 DOI: 10.1186/1475-2859-13-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 12/29/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Over the recent years the production of Ehrlich pathway derived chemicals was shown in a variety of hosts such as Escherichia coli, Corynebacterium glutamicum, and yeast. Exemplarily the production of isobutyric acid was demonstrated in Escherichia coli with remarkable titers and yields. However, these examples suffer from byproduct formation due to the fermentative growth mode of the respective organism. We aim at establishing a new aerobic, chassis for the synthesis of isobutyric acid and other interesting metabolites using Pseudomonas sp. strain VLB120, an obligate aerobe organism, as host strain. RESULTS The overexpression of kivd, coding for a 2-ketoacid decarboxylase from Lactococcus lactis in Ps. sp. strain VLB120 enabled for the production of isobutyric acid and isobutanol via the valine synthesis route (Ehrlich pathway). This indicates the existence of chromosomally encoded alcohol and aldehyde dehydrogenases catalyzing the reduction and oxidation of isobutyraldehyde. In addition we showed that the strain possesses a complete pathway for isobutyric acid metabolization, channeling the compound via isobutyryl-CoA into valine degradation. Three key issues were addressed to allow and optimize isobutyric acid synthesis: i) minimizing isobutyric acid degradation by host intrinsic enzymes, ii) construction of suitable expression systems and iii) streamlining of central carbon metabolism finally leading to production of up to 26.8 ± 1.5 mM isobutyric acid with a carbon yield of 0.12 ± 0.01 g g(glc)⁻¹. CONCLUSION The combination of an increased flux towards isobutyric acid using a tailor-made expression system and the prevention of precursor and product degradation allowed efficient production of isobutyric acid in Ps. sp. strain VLB120. This will be the basis for the development of a continuous reaction process for this bulk chemicals.
Collapse
|
40
|
Hellriegel J, Günther S, Kampen I, Bolea Albero A, Kwade A, Böl M, Krull R. A Biomimetic Gellan-Based Hydrogel as a Physicochemical Biofilm Model. ACTA ACUST UNITED AC 2014. [DOI: 10.4236/jbnb.2014.52011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
41
|
Application of biofilm bioreactors in white biotechnology. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2014; 146:123-61. [PMID: 24402458 DOI: 10.1007/10_2013_267] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The production of valuable compounds in industrial biotechnology is commonly done by cultivation of suspended cells or use of (immobilized) enzymes rather than using microorganisms in an immobilized state. Within the field of wastewater as well as odor treatment the application of immobilized cells is a proven technique. The cells are entrapped in a matrix of extracellular polymeric compounds produced by themselves. The surface-associated agglomerate of encapsulated cells is termed biofilm. In comparison to common immobilization techniques, toxic effects of compounds used for cell entrapment may be neglected. Although the economic impact of biofilm processes used for the production of valuable compounds is negligible, many prospective approaches were examined in the laboratory and on a pilot scale. This review gives an overview of biofilm reactors applied to the production of valuable compounds. Moreover, the characteristics of the utilized materials are discussed with respect to support of surface-attached microbial growth.
Collapse
|