1
|
Liu A, Ellis D, Mhatre A, Brahmankar S, Seto J, Nielsen DR, Varman AM. Biomanufacturing of value-added chemicals from lignin. Curr Opin Biotechnol 2024; 89:103178. [PMID: 39098292 DOI: 10.1016/j.copbio.2024.103178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 07/16/2024] [Accepted: 07/22/2024] [Indexed: 08/06/2024]
Abstract
Lignin valorization faces persistent biomanufacturing challenges due to the heterogeneous and toxic carbon substrates derived from lignin depolymerization. To address the heterogeneous nature of aromatic feedstocks, plant cell wall engineering and 'lignin first' pretreatment methods have recently emerged. Next, to convert the resulting aromatic substrates into value-added chemicals, diverse microbial host systems also continue to be developed. This includes microbes that (1) lack aromatic metabolism, (2) metabolize aromatics but not sugars, and (3) co-metabolize both aromatics and sugars, each system presenting unique pros and cons. Considering the intrinsic complexity of lignin-derived substrate mixtures, emerging and non-model microbes with native metabolism for aromatics appear poised to provide the greatest impacts on lignin valorization via biomanufacturing.
Collapse
Affiliation(s)
- Arren Liu
- Biological Design Program, School for Engineering of Matter, Transport, and Energy, Arizona State University, Tempe, AZ, USA
| | - Dylan Ellis
- Chemical Engineering Program, School for Engineering of Matter, Transport, and Energy, Arizona State University, Tempe, AZ, USA
| | - Apurv Mhatre
- Chemical Engineering Program, School for Engineering of Matter, Transport, and Energy, Arizona State University, Tempe, AZ, USA
| | - Sumant Brahmankar
- Chemical Engineering Program, School for Engineering of Matter, Transport, and Energy, Arizona State University, Tempe, AZ, USA
| | - Jong Seto
- Chemical Engineering Program, School for Engineering of Matter, Transport, and Energy, Arizona State University, Tempe, AZ, USA
| | - David R Nielsen
- Biological Design Program, School for Engineering of Matter, Transport, and Energy, Arizona State University, Tempe, AZ, USA; Chemical Engineering Program, School for Engineering of Matter, Transport, and Energy, Arizona State University, Tempe, AZ, USA
| | - Arul M Varman
- Biological Design Program, School for Engineering of Matter, Transport, and Energy, Arizona State University, Tempe, AZ, USA; Chemical Engineering Program, School for Engineering of Matter, Transport, and Energy, Arizona State University, Tempe, AZ, USA.
| |
Collapse
|
2
|
Li DH, Zheng N, Liu ZH, Dong XR, Zhao C, Yan SG, Xie BB. Complete genome sequence of the 4-hydroxybenzoate-degrading bacterium Gymnodinialimonas sp. 57CJ19, a potential novel species from intertidal sediments. Mar Genomics 2024; 77:101135. [PMID: 39179312 DOI: 10.1016/j.margen.2024.101135] [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] [Received: 06/14/2024] [Revised: 07/10/2024] [Accepted: 07/11/2024] [Indexed: 08/26/2024]
Abstract
A bacterium Gymnodinialimonas sp. 57CJ19, was isolated from the intertidal sediments of Aoshan Bay, and further assays showed that it has the ability to degrade the antibacterial preservative 4-hydroxybenzoate. The complete genome sequence was sequenced, and phylogenomic analyses indicated that strain 57CJ19 represents a potential novel species in the genus Gymnodinialimonas (family Rhodobacteraceae). Its genome contains a 3,861,607-bp circular chromosome with 61.25% G + C content. Gene prediction revealed 3716 protein-encoding genes, 41 tRNA genes, 3 rrn operons, and 3 non-coding RNA genes. Functional annotation revealed a complete metabolic pathway for 4-hydroxybenzoate. The genome sequence of strain 57CJ19 provides new insights into the potential and underlying genomic basis of aromatic compound pollutant degradation by marine bacteria.
Collapse
Affiliation(s)
- Dong-Hui Li
- School of Bioengineering, Shandong Provincial Key Laboratory of Bioengineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China
| | - Ning Zheng
- Microbial Technology Institute and State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Zhen-Hai Liu
- School of Bioengineering, Shandong Provincial Key Laboratory of Bioengineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China
| | - Xiao-Rui Dong
- School of Bioengineering, Shandong Provincial Key Laboratory of Bioengineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China
| | - Chen Zhao
- School of Bioengineering, Shandong Provincial Key Laboratory of Bioengineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China
| | - Shi-Gan Yan
- School of Bioengineering, Shandong Provincial Key Laboratory of Bioengineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China.
| | - Bin-Bin Xie
- Microbial Technology Institute and State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China.
| |
Collapse
|
3
|
He Z, Jiang G, Gan L, He T, Tian Y. Bacterial valorization of lignin for the sustainable production of value-added bioproducts. Int J Biol Macromol 2024; 279:135171. [PMID: 39214219 DOI: 10.1016/j.ijbiomac.2024.135171] [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: 04/21/2024] [Revised: 08/09/2024] [Accepted: 08/27/2024] [Indexed: 09/04/2024]
Abstract
As the most abundant aromatic biopolymer in the biosphere, lignin represents a promising alternative feedstock for the industrial production of various value-added bioproducts with enhanced economical value. However, the large-scale implementation of lignin valorization remains challenging because of the heterogeneity and irregular structure of lignin. General fragmentation and depolymerization processes often yield various products, but these approaches necessitate tedious purification steps to isolate target products. Moreover, microbial biocatalytic processes, especially bacterial-based systems with high metabolic activity, can depolymerize and further utilize lignin in an eco-friendly way. Considering that wild bacterial strains have evolved several metabolic pathways and enzymatic systems for lignin degradation, substantial efforts have been made to exploit their potential for lignin valorization. This review summarizes recent advances in lignin valorization for the production of value-added bioproducts based on bacterial systems. Additionally, the remaining challenges and available strategies for lignin biodegradation processes and future trends of bacterial lignin valorization are discussed.
Collapse
Affiliation(s)
- Zhicheng He
- Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), College of Life Sciences, Guizhou University, Guiyang 550025, Guizhou Province, China
| | - Guangyang Jiang
- Key Laboratory of Leather Chemistry and Engineering (Ministry of Education), College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, Sichuan Province, China
| | - Longzhan Gan
- Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), College of Life Sciences, Guizhou University, Guiyang 550025, Guizhou Province, China.
| | - Tengxia He
- Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), College of Life Sciences, Guizhou University, Guiyang 550025, Guizhou Province, China
| | - Yongqiang Tian
- Key Laboratory of Leather Chemistry and Engineering (Ministry of Education), College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, Sichuan Province, China.
| |
Collapse
|
4
|
Anthony WE, Geng W, Diao J, Carr RR, Wang B, Ning J, Moon TS, Dantas G, Zhang F. Increased triacylglycerol production in Rhodococcus opacus by overexpressing transcriptional regulators. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2024; 17:83. [PMID: 38898475 PMCID: PMC11186279 DOI: 10.1186/s13068-024-02523-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Accepted: 05/23/2024] [Indexed: 06/21/2024]
Abstract
Lignocellulosic biomass is currently underutilized, but it offers promise as a resource for the generation of commercial end-products, such as biofuels, detergents, and other oleochemicals. Rhodococcus opacus PD630 is an oleaginous, Gram-positive bacterium with an exceptional ability to utilize recalcitrant aromatic lignin breakdown products to produce lipid molecules such as triacylglycerols (TAGs), which are an important biofuel precursor. Lipid carbon storage molecules accumulate only under growth-limiting low nitrogen conditions, representing a significant challenge toward using bacterial biorefineries for fuel precursor production. In this work, we screened overexpression of 27 native transcriptional regulators for their abilities to improve lipid accumulation under nitrogen-rich conditions, resulting in three strains that accumulate increased lipids, unconstrained by nitrogen availability when grown in phenol or glucose. Transcriptomic analyses revealed that the best strain (#13) enhanced FA production via activation of the β-ketoadipate pathway. Gene deletion experiments confirm that lipid accumulation in nitrogen-replete conditions requires reprogramming of phenylalanine metabolism. By generating mutants decoupling carbon storage from low nitrogen environments, we move closer toward optimizing R. opacus for efficient bioproduction on lignocellulosic biomass.
Collapse
Affiliation(s)
- Winston E Anthony
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Department of Pathology and Immunology, Division of Laboratory and Genomic Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Earth and Biological Systems Directorate, Pacific Northwest National Laboratory, Seattle, USA
| | - Weitao Geng
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Jinjin Diao
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Rhiannon R Carr
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Bin Wang
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Department of Pathology and Immunology, Division of Laboratory and Genomic Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Jie Ning
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Department of Pathology and Immunology, Division of Laboratory and Genomic Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Tae Seok Moon
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA.
- Division of Biology and Biomedical Sciences, Washington University in St. Louis, St. Louis, MO, 63130, USA.
| | - Gautam Dantas
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine, St. Louis, MO, 63110, USA.
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA.
- Division of Biology and Biomedical Sciences, Washington University in St. Louis, St. Louis, MO, 63130, USA.
- Department of Molecular Microbiology, Washington University School of Medicine in St Louis, St Louis, MO, 63110, USA.
- Department of Pediatrics, Washington University School of Medicine in St Louis, St Louis, MO, 63110, USA.
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA.
| | - Fuzhong Zhang
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA.
- Division of Biology and Biomedical Sciences, Washington University in St. Louis, St. Louis, MO, 63130, USA.
- Institute of Materials Science & Engineering, Washington University in St Louis, St Louis, MO, 63130, USA.
| |
Collapse
|
5
|
Benning S, Pritsch K, Radl V, Siani R, Wang Z, Schloter M. (Pan)genomic analysis of two Rhodococcus isolates and their role in phenolic compound degradation. Microbiol Spectr 2024; 12:e0378323. [PMID: 38376357 PMCID: PMC10986565 DOI: 10.1128/spectrum.03783-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 01/25/2024] [Indexed: 02/21/2024] Open
Abstract
The genus Rhodococcus is recognized for its potential to degrade a large range of aromatic substances, including plant-derived phenolic compounds. We used comparative genomics in the context of the broader Rhodococcus pan-genome to study genomic traits of two newly described Rhodococcus strains (type-strain Rhodococcus pseudokoreensis R79T and Rhodococcus koreensis R85) isolated from apple rhizosphere. Of particular interest was their ability to degrade phenolic compounds as part of an integrated approach to treat apple replant disease (ARD) syndrome. The pan-genome of the genus Rhodococcus based on 109 high-quality genomes was open with a small core (1.3%) consisting of genes assigned to basic cell functioning. The range of genome sizes in Rhodococcus was high, from 3.7 to 10.9 Mbp. Genomes from host-associated strains were generally smaller compared to environmental isolates which were characterized by exceptionally large genome sizes. Due to large genomic differences, we propose the reclassification of distinct groups of rhodococci like the Rhodococcus equi cluster to new genera. Taxonomic species affiliation was the most important factor in predicting genetic content and clustering of the genomes. Additionally, we found genes that discriminated between the strains based on habitat. All members of the genus Rhodococcus had at least one gene involved in the pathway for the degradation of benzoate, while biphenyl degradation was mainly restricted to strains in close phylogenetic relationships with our isolates. The ~40% of genes still unclassified in larger Rhodococcus genomes, particularly those of environmental isolates, need more research to explore the metabolic potential of this genus.IMPORTANCERhodococcus is a diverse, metabolically powerful genus, with high potential to adapt to different habitats due to the linear plasmids and large genome sizes. The analysis of its pan-genome allowed us to separate host-associated from environmental strains, supporting taxonomic reclassification. It was shown which genes contribute to the differentiation of the genomes based on habitat, which can possibly be used for targeted isolation and screening for desired traits. With respect to apple replant disease (ARD), our isolates showed genome traits that suggest potential for application in reducing plant-derived phenolic substances in soil, which makes them good candidates for further testing against ARD.
Collapse
Affiliation(s)
- Sarah Benning
- Research Unit for Comparative Microbiome Analysis, Helmholtz Munich, German Research Center for Environmental Health, Neuherberg, Germany
| | - Karin Pritsch
- Research Unit for Environmental Simulations, Helmholtz Munich, German Research Center for Environmental Health, Neuherberg, Germany
| | - Viviane Radl
- Research Unit for Comparative Microbiome Analysis, Helmholtz Munich, German Research Center for Environmental Health, Neuherberg, Germany
| | - Roberto Siani
- Research Unit for Comparative Microbiome Analysis, Helmholtz Munich, German Research Center for Environmental Health, Neuherberg, Germany
| | - Zhongjie Wang
- Research Unit for Comparative Microbiome Analysis, Helmholtz Munich, German Research Center for Environmental Health, Neuherberg, Germany
| | - Michael Schloter
- Research Unit for Comparative Microbiome Analysis, Helmholtz Munich, German Research Center for Environmental Health, Neuherberg, Germany
- Chair for Environmental Microbiology, TUM School of Life Sciences, Technical University Munich, Munich, Germany
| |
Collapse
|
6
|
Tsagogiannis E, Asimakoula S, Drainas AP, Marinakos O, Boti VI, Kosma IS, Koukkou AI. Elucidation of 4-Hydroxybenzoic Acid Catabolic Pathways in Pseudarthrobacter phenanthrenivorans Sphe3. Int J Mol Sci 2024; 25:843. [PMID: 38255919 PMCID: PMC10815724 DOI: 10.3390/ijms25020843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 01/05/2024] [Accepted: 01/08/2024] [Indexed: 01/24/2024] Open
Abstract
4-hydroxybenzoic acid (4-HBA) is an aromatic compound with high chemical stability, being extensively used in food, pharmaceutical and cosmetic industries and therefore widely distributed in various environments. Bioremediation constitutes the most sustainable approach for the removal of 4-hydroxybenzoate and its derivatives (parabens) from polluted environments. Pseudarthrobacter phenanthrenivorans Sphe3, a strain capable of degrading several aromatic compounds, is able to grow on 4-HBA as the sole carbon and energy source. Here, an attempt is made to clarify the catabolic pathways that are involved in the biodegradation of 4-hydroxybenzoate by Sphe3, applying a metabolomic and transcriptomic analysis of cells grown on 4-HBA. It seems that in Sphe3, 4-hydroxybenzoate is hydroxylated to form protocatechuate, which subsequently is either cleaved in ortho- and/or meta-positions or decarboxylated to form catechol. Protocatechuate and catechol are funneled into the TCA cycle following either the β-ketoadipate or protocatechuate meta-cleavage branches. Our results also suggest the involvement of the oxidative decarboxylation of the protocatechuate peripheral pathway to form hydroxyquinol. As a conclusion, P. phenanthrenivorans Sphe3 seems to be a rather versatile strain considering the 4-hydroxybenzoate biodegradation, as it has the advantage to carry it out effectively following different catabolic pathways concurrently.
Collapse
Affiliation(s)
- Epameinondas Tsagogiannis
- Laboratory of Biochemistry, Sector of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece; (E.T.); (S.A.); (A.P.D.); (O.M.)
| | - Stamatia Asimakoula
- Laboratory of Biochemistry, Sector of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece; (E.T.); (S.A.); (A.P.D.); (O.M.)
| | - Alexandros P. Drainas
- Laboratory of Biochemistry, Sector of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece; (E.T.); (S.A.); (A.P.D.); (O.M.)
| | - Orfeas Marinakos
- Laboratory of Biochemistry, Sector of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece; (E.T.); (S.A.); (A.P.D.); (O.M.)
| | - Vasiliki I. Boti
- Unit of Environmental, Organic and Biochemical High-Resolution Analysis-Orbitrap-LC-MS, University of Ioannina, 451110 Ioannina, Greece;
| | - Ioanna S. Kosma
- Laboratory of Food Chemistry, Sector of Industrial Chemistry and Food Chemistry, Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece;
| | - Anna-Irini Koukkou
- Laboratory of Biochemistry, Sector of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece; (E.T.); (S.A.); (A.P.D.); (O.M.)
| |
Collapse
|
7
|
Zhao ZM, Liu ZH, Zhang T, Meng R, Gong Z, Li Y, Hu J, Ragauskas AJ, Li BZ, Yuan YJ. Unleashing the capacity of Rhodococcus for converting lignin into lipids. Biotechnol Adv 2024; 70:108274. [PMID: 37913947 DOI: 10.1016/j.biotechadv.2023.108274] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 09/11/2023] [Accepted: 10/22/2023] [Indexed: 11/03/2023]
Abstract
Bioconversion of bioresources/wastes (e.g., lignin, chemical pulping byproducts) represents a promising approach for developing a bioeconomy to help address growing energy and materials demands. Rhodococcus, a promising microbial strain, utilizes numerous carbon sources to produce lipids, which are precursors for synthesizing biodiesel and aviation fuels. However, compared to chemical conversion, bioconversion involves living cells, which is a more complex system that needs further understanding and upgrading. Various wastes amenable to bioconversion are reviewed herein to highlight the potential of Rhodococci for producing lipid-derived bioproducts. In light of the abundant availability of these substrates, Rhodococcus' metabolic pathways converting them to lipids are analyzed from a "beginning-to-end" view. Based on an in-depth understanding of microbial metabolic routes, genetic modifications of Rhodococcus by employing emerging tools (e.g., multiplex genome editing, biosensors, and genome-scale metabolic models) are presented for promoting the bioconversion. Co-solvent enhanced lignocellulose fractionation (CELF) strategy facilitates the generation of a lignin-derived aromatic stream suitable for the Rhodococcus' utilization. Novel alkali sterilization (AS) and elimination of thermal sterilization (ETS) approaches can significantly enhance the bioaccessibility of lignin and its derived aromatics in aqueous fermentation media, which promotes lipid titer significantly. In order to achieve value-added utilization of lignin, biodiesel and aviation fuel synthesis from lignin and lipids are further discussed. The possible directions for unleashing the capacity of Rhodococcus through synergistically modifying microbial strains, substrates, and fermentation processes are proposed toward a sustainable biological lignin valorization.
Collapse
Affiliation(s)
- Zhi-Min Zhao
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; Department of Chemical & Biomolecular Engineering, University of Tennessee, Knoxville, TN 37996, United States; Key Laboratory of Ecology and Resource Use of the Mongolian Plateau (Ministry of Education), School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China
| | - Zhi-Hua Liu
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Tongtong Zhang
- Key Laboratory of Ecology and Resource Use of the Mongolian Plateau (Ministry of Education), School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China
| | - Rongqian Meng
- Key Laboratory of Ecology and Resource Use of the Mongolian Plateau (Ministry of Education), School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China
| | - Zhiqun Gong
- Key Laboratory of Ecology and Resource Use of the Mongolian Plateau (Ministry of Education), School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China
| | - Yibing Li
- Key Laboratory of Ecology and Resource Use of the Mongolian Plateau (Ministry of Education), School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China
| | - Jing Hu
- Key Laboratory of Ecology and Resource Use of the Mongolian Plateau (Ministry of Education), School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China
| | - Arthur J Ragauskas
- Department of Chemical & Biomolecular Engineering, University of Tennessee, Knoxville, TN 37996, United States; Joint Institute of Biological Science, Biosciences Division, Oak Ridge National Laboratory (ORNL), Oak Ridge, TN 37831, United States; Department of Forestry, Wildlife, and Fisheries, Center for Renewable Carbon, University of Tennessee Institute of Agriculture, Knoxville, TN 37996, United States.
| | - Bing-Zhi Li
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
| | - Ying-Jin Yuan
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| |
Collapse
|
8
|
Xi C, Diao J, Moon TS. Advances in ligand-specific biosensing for structurally similar molecules. Cell Syst 2023; 14:1024-1043. [PMID: 38128482 PMCID: PMC10751988 DOI: 10.1016/j.cels.2023.10.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Revised: 08/23/2023] [Accepted: 10/19/2023] [Indexed: 12/23/2023]
Abstract
The specificity of biological systems makes it possible to develop biosensors targeting specific metabolites, toxins, and pollutants in complex medical or environmental samples without interference from structurally similar compounds. For the last two decades, great efforts have been devoted to creating proteins or nucleic acids with novel properties through synthetic biology strategies. Beyond augmenting biocatalytic activity, expanding target substrate scopes, and enhancing enzymes' enantioselectivity and stability, an increasing research area is the enhancement of molecular specificity for genetically encoded biosensors. Here, we summarize recent advances in the development of highly specific biosensor systems and their essential applications. First, we describe the rational design principles required to create libraries containing potential mutants with less promiscuity or better specificity. Next, we review the emerging high-throughput screening techniques to engineer biosensing specificity for the desired target. Finally, we examine the computer-aided evaluation and prediction methods to facilitate the construction of ligand-specific biosensors.
Collapse
Affiliation(s)
- Chenggang Xi
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Jinjin Diao
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Tae Seok Moon
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO, USA; Division of Biology and Biomedical Sciences, Washington University in St. Louis, St. Louis, MO, USA.
| |
Collapse
|
9
|
Li X, Gluth A, Feng S, Qian WJ, Yang B. Harnessing redox proteomics to study metabolic regulation and stress response in lignin-fed Rhodococci. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:180. [PMID: 37986172 PMCID: PMC10662689 DOI: 10.1186/s13068-023-02424-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Accepted: 11/02/2023] [Indexed: 11/22/2023]
Abstract
BACKGROUND Rhodococci are studied for their bacterial ligninolytic capabilities and proclivity to accumulate lipids. Lignin utilization is a resource intensive process requiring a variety of redox active enzymes and cofactors for degradation as well as defense against the resulting toxic byproducts and oxidative conditions. Studying enzyme expression and regulation between carbon sources will help decode the metabolic rewiring that stymies lignin to lipid conversion in these bacteria. Herein, a redox proteomics approach was applied to investigate a fundamental driver of carbon catabolism and lipid anabolism: redox balance. RESULTS A consortium of Rhodococcus strains was employed in this study given its higher capacity for lignin degradation compared to monocultures. This consortium was grown on glucose vs. lignin under nitrogen limitation to study the importance of redox balance as it relates to nutrient availability. A modified bottom-up proteomics workflow was harnessed to acquire a general relationship between protein abundance and protein redox states. Global proteomics results affirm differential expression of enzymes involved in sugar metabolism vs. those involved in lignin degradation and aromatics metabolism. As reported previously, several enzymes in the lipid biosynthetic pathways were downregulated, whereas many involved in β-oxidation were upregulated. Interestingly, proteins involved in oxidative stress response were also upregulated perhaps in response to lignin degradation and aromatics catabolism, which require oxygen and reactive oxygen species and generate toxic byproducts. Enzymes displaying little-to-no change in abundance but differences in redox state were observed in various pathways for carbon utilization (e.g., β‑ketoadipate pathway), lipid metabolism, as well as nitrogen metabolism (e.g., purine scavenging/synthesis), suggesting potential mechanisms of redox-dependent regulation of metabolism. CONCLUSIONS Efficient lipid production requires a steady carbon and energy flux while balancing fundamental requirements for enzyme production and cell maintenance. For lignin, we theorize that this balance is difficult to establish due to resource expenditure for enzyme production and stress response. This is supported by significant changes to protein abundances and protein cysteine oxidation in various metabolic pathways and redox processes.
Collapse
Affiliation(s)
- Xiaolu Li
- Bioproducts, Sciences, and Engineering Laboratory, Department of Biological Systems Engineering, Washington State University, Richland, WA, 99354, USA
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Austin Gluth
- Bioproducts, Sciences, and Engineering Laboratory, Department of Biological Systems Engineering, Washington State University, Richland, WA, 99354, USA
| | - Song Feng
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Wei-Jun Qian
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Bin Yang
- Bioproducts, Sciences, and Engineering Laboratory, Department of Biological Systems Engineering, Washington State University, Richland, WA, 99354, USA.
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
| |
Collapse
|
10
|
Wang Y, Luo CB, Li YQ. Biofuneling lignin-derived compounds into lipids using a newly isolated Citricoccus sp. P2. BIORESOURCE TECHNOLOGY 2023; 387:129669. [PMID: 37573985 DOI: 10.1016/j.biortech.2023.129669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 08/08/2023] [Accepted: 08/09/2023] [Indexed: 08/15/2023]
Abstract
Lignin-derived compounds (LDCs) bioconversion into lipids is a promising yet challenging task. This study focuses on the isolation of the ligninolytic bacterium Citricoccus sp. P2 and investigates its mechanism for producing lipids from LDCs. Although strain P2 exhibits a relatively low lignin degradation rate of 44.63%, it efficiently degrades various concentrations of LDCs. The highest degradation rate is observed when incubated with 0.6 g/L vanillic acid, 0.6 g/L syringic acid, 0.8 g/L p-coumaric acid, and 0.4 g/L phenol, resulting in respective lipid yields of 0.16 g/L, 0.13 g/L, 0.24 g/L, and 0.13 g/L. The genome of strain P2 provides insights into LDCs bioconversion into lipids and stress tolerance. Moreover, Citricoccus sp. P2 has been successfully developed a non-sterilized lipid production using its native alkali-halophilic characteristics, which significantly enhances the lipid yield. This study presents a promising platform for lipids production from LDCs and has potential to promote valorization of lignin.
Collapse
Affiliation(s)
- Yan Wang
- College of Life Science, Leshan Normal University, Leshan 614000, China
| | - Chao-Bing Luo
- College of Life Science, Leshan Normal University, Leshan 614000, China
| | - Yuan-Qiu Li
- College of Life Science, Leshan Normal University, Leshan 614000, China.
| |
Collapse
|
11
|
Xue L, Zhao Y, Li L, Rao X, Chen X, Ma F, Yu H, Xie S. A key O-demethylase in the degradation of guaiacol by Rhodococcus opacus PD630. Appl Environ Microbiol 2023; 89:e0052223. [PMID: 37800939 PMCID: PMC10617553 DOI: 10.1128/aem.00522-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 07/24/2023] [Indexed: 10/07/2023] Open
Abstract
Rhodococcus opacus PD630 is a high oil-producing strain with the ability to convert lignin-derived aromatics to high values, but limited research has been done to elucidate its conversion pathway, especially the upper pathways. In this study, we focused on the upper pathways and demethylation mechanism of lignin-derived aromatics metabolism by R. opacus PD630. The results of the aromatic carbon resource utilization screening showed that R. opacus PD630 had a strong degradation capacity to the lignin-derived methoxy-containing aromatics, such as guaiacol, 3,4-veratric acid, anisic acid, isovanillic acid, and vanillic acid. The gene of gcoAR, which encodes cytochrome P450, showed significant up-regulation when R. opacus PD630 grew on diverse aromatics. Deletion mutants of gcoAR and its partner protein gcoBR resulted in the strain losing the ability to grow on guaiacol, but no significant difference to the other aromatics. Only co-complementation alone of gcoAR and gcoBR restored the strain's ability to utilize guaiacol, demonstrating that both genes were equally important in the utilization of guaiacol. In vitro assays further revealed that GcoAR could convert guaiacol and anisole to catechol and phenol, respectively, with the production of formaldehyde as a by-product. The study provided robust evidence to reveal the molecular mechanism of R. opacus PD630 on guaiacol metabolism and offered a promising study model for dissecting the demethylation process of lignin-derived aromatics in microbes.IMPORTANCEAryl-O-demethylation is believed to be the key rate-limiting step in the catabolism of heterogeneous lignin-derived aromatics in both native and engineered microbes. However, the mechanisms of O-demethylation in lignin-derived aromatic catabolism remain unclear. Notably, guaiacol, the primary component unit of lignin, lacks in situ demonstration and illustration of the molecular mechanism of guaiacol O-demethylation in lignin-degrading bacteria. This is the first study to illustrate the mechanism of guaiacol metabolism by R. opacus PD630 in situ as well as characterize the purified key O-demethylase in vitro. This study provided further insight into the lignin metabolic pathway of R. opacus PD630 and could guide the design of an efficient biocatalytic system for lignin valorization.
Collapse
Affiliation(s)
- Le Xue
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Yiquan Zhao
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Ling Li
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Xinran Rao
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Xinjie Chen
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Fuying Ma
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Hongbo Yu
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Shangxian Xie
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
| |
Collapse
|
12
|
Grechishnikova EG, Shemyakina AO, Novikov AD, Lavrov KV, Yanenko AS. Rhodococcus: sequences of genetic parts, analysis of their functionality, and development prospects as a molecular biology platform. Crit Rev Biotechnol 2023; 43:835-850. [PMID: 35786136 DOI: 10.1080/07388551.2022.2091976] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Revised: 04/19/2022] [Accepted: 05/12/2022] [Indexed: 12/19/2022]
Abstract
Rhodococcus bacteria are a fast-growing platform for biocatalysis, biodegradation, and biosynthesis, but not a platform for molecular biology. That is, Rhodococcus are not convenient for genetic engineering. One major issue for the engineering of Rhodococcus is the absence of a publicly available, curated, and commented collection of sequences of genetic parts that are functional in biotechnologically relevant species of Rhodococcus (R. erythropolis, R. rhodochrous, R. ruber, and R. jostii). Here, we present a collection of genetic parts for Rhodococcus (vector replicons, promoter regions, regulators, markers, and reporters) supported by a thorough analysis of their functionality. We also highlight and discuss the gaps in Rhodococcus-related genetic parts and techniques, which should be filled in order to make these bacteria a full-fledged molecular biology platform independent of Escherichia coli. We conclude that all major types of required genetic parts for Rhodococcus are available now, except multicopy replicons. As for model Rhodococcus strains, there is a particular shortage of strains with high electrocompetence levels and strains designed for solving specific genetic engineering tasks. We suggest that these obstacles are surmountable in the near future due to an intensification of research work in the field of genetic techniques for non-conventional bacteria.
Collapse
Affiliation(s)
- Elena G Grechishnikova
- NRC "Kurchatov Institute" - GOSNIIGENETIKA, Kurchatov Genomic Center, Moscow, Russia
- NRC "Kurchatov Institute", Moscow, Russia
| | - Anna O Shemyakina
- NRC "Kurchatov Institute" - GOSNIIGENETIKA, Kurchatov Genomic Center, Moscow, Russia
- NRC "Kurchatov Institute", Moscow, Russia
| | - Andrey D Novikov
- NRC "Kurchatov Institute" - GOSNIIGENETIKA, Kurchatov Genomic Center, Moscow, Russia
- NRC "Kurchatov Institute", Moscow, Russia
| | - Konstantin V Lavrov
- NRC "Kurchatov Institute" - GOSNIIGENETIKA, Kurchatov Genomic Center, Moscow, Russia
- NRC "Kurchatov Institute", Moscow, Russia
| | - Alexander S Yanenko
- NRC "Kurchatov Institute" - GOSNIIGENETIKA, Kurchatov Genomic Center, Moscow, Russia
- NRC "Kurchatov Institute", Moscow, Russia
| |
Collapse
|
13
|
Roell G, Schenk C, Anthony WE, Carr RR, Ponukumati A, Kim J, Akhmatskaya E, Foston M, Dantas G, Moon TS, Tang YJ, García Martín H. A High-Quality Genome-Scale Model for Rhodococcus opacus Metabolism. ACS Synth Biol 2023; 12:1632-1644. [PMID: 37186551 PMCID: PMC10278598 DOI: 10.1021/acssynbio.2c00618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Indexed: 05/17/2023]
Abstract
Rhodococcus opacus is a bacterium that has a high tolerance to aromatic compounds and can produce significant amounts of triacylglycerol (TAG). Here, we present iGR1773, the first genome-scale model (GSM) of R. opacus PD630 metabolism based on its genomic sequence and associated data. The model includes 1773 genes, 3025 reactions, and 1956 metabolites, was developed in a reproducible manner using CarveMe, and was evaluated through Metabolic Model tests (MEMOTE). We combine the model with two Constraint-Based Reconstruction and Analysis (COBRA) methods that use transcriptomics data to predict growth rates and fluxes: E-Flux2 and SPOT (Simplified Pearson Correlation with Transcriptomic data). Growth rates are best predicted by E-Flux2. Flux profiles are more accurately predicted by E-Flux2 than flux balance analysis (FBA) and parsimonious FBA (pFBA), when compared to 44 central carbon fluxes measured by 13C-Metabolic Flux Analysis (13C-MFA). Under glucose-fed conditions, E-Flux2 presents an R2 value of 0.54, while predictions based on pFBA had an inferior R2 of 0.28. We attribute this improved performance to the extra activity information provided by the transcriptomics data. For phenol-fed metabolism, in which the substrate first enters the TCA cycle, E-Flux2's flux predictions display a high R2 of 0.96 while pFBA showed an R2 of 0.93. We also show that glucose metabolism and phenol metabolism function with similar relative ATP maintenance costs. These findings demonstrate that iGR1773 can help the metabolic engineering community predict aromatic substrate utilization patterns and perform computational strain design.
Collapse
Affiliation(s)
- Garrett
W. Roell
- Department
of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Christina Schenk
- BCAM
- Basque Center for Applied Mathematics, Bilbao 48009, Spain
- Biological
Systems and Engineering Division, Lawrence
Berkeley National Lab, Berkeley, California 94720, United States
| | - Winston E. Anthony
- The Edison
Family Center for Genome Sciences and Systems Biology, Washington University in St. Louis School of Medicine, St. Louis, Missouri 63110, United States
- Department
of Pathology and Immunology, Washington
University in St. Louis School of Medicine, St. Louis, Missouri 63108, United States
| | - Rhiannon R. Carr
- Department
of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Aditya Ponukumati
- Department
of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Joonhoon Kim
- DOE
Agile BioFoundry, Emeryville, California 94608, United States
- DOE
Joint BioEnergy Institute, Emeryville, California 94608, United States
| | - Elena Akhmatskaya
- BCAM
- Basque Center for Applied Mathematics, Bilbao 48009, Spain
- Biological
Systems and Engineering Division, Lawrence
Berkeley National Lab, Berkeley, California 94720, United States
- IKERBASQUE,
Basque Foundation for Science, Bilbao 48009, Spain
| | - Marcus Foston
- Department
of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Gautam Dantas
- The Edison
Family Center for Genome Sciences and Systems Biology, Washington University in St. Louis School of Medicine, St. Louis, Missouri 63110, United States
- Department
of Pathology and Immunology, Washington
University in St. Louis School of Medicine, St. Louis, Missouri 63108, United States
- Department
of Biomedical Engineering, Washington University
in St. Louis, St Louis, Missouri 63130, United States
- Department
of Molecular Microbiology, Washington University
in St. Louis School of Medicine, St. Louis, Missouri 63108, United States
- Department
of Pediatrics, Washington University School
of Medicine in St Louis, St Louis, Missouri 63110, United States
| | - Tae Seok Moon
- Department
of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Yinjie J. Tang
- Department
of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Hector García Martín
- BCAM
- Basque Center for Applied Mathematics, Bilbao 48009, Spain
- DOE
Agile BioFoundry, Emeryville, California 94608, United States
- Biological
Systems and Engineering Division, Lawrence
Berkeley National Lab, Berkeley, California 94720, United States
- DOE
Joint BioEnergy Institute, Emeryville, California 94608, United States
| |
Collapse
|
14
|
Borchert AJ, Bleem A, Beckham GT. RB-TnSeq identifies genetic targets for improved tolerance of Pseudomonas putida towards compounds relevant to lignin conversion. Metab Eng 2023; 77:208-218. [PMID: 37059293 DOI: 10.1016/j.ymben.2023.04.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Revised: 03/21/2023] [Accepted: 04/12/2023] [Indexed: 04/16/2023]
Abstract
Lignin-derived mixtures intended for bioconversion commonly contain high concentrations of aromatic acids, aliphatic acids, and salts. The inherent toxicity of these chemicals places a significant bottleneck upon the effective use of microbial systems for the valorization of these mixtures. Pseudomonas putida KT2440 can tolerate stressful quantities of several lignin-related compounds, making this bacterium a promising host for converting these chemicals to valuable bioproducts. Nonetheless, further increasing P. putida tolerance to chemicals in lignin-rich substrates has the potential to improve bioprocess performance. Accordingly, we employed random barcoded transposon insertion sequencing (RB-TnSeq) to reveal genetic determinants in P. putida KT2440 that influence stress outcomes during exposure to representative constituents found in lignin-rich process streams. The fitness information obtained from the RB-TnSeq experiments informed engineering of strains via deletion or constitutive expression of several genes. Namely, ΔgacAS, ΔfleQ, ΔlapAB, ΔttgR::Ptac:ttgABC, Ptac:PP_1150:PP_1152, ΔrelA, and ΔPP_1430 mutants showed growth improvement in the presence of single compounds, and some also exhibited greater tolerance when grown using a complex chemical mixture representative of a lignin-rich chemical stream. Overall, this work demonstrates the successful implementation of a genome-scale screening tool for the identification of genes influencing stress tolerance against notable compounds within lignin-enriched chemical streams, and the genetic targets identified herein offer promising engineering targets for improving feedstock tolerance in lignin valorization strains of P. putida KT2440.
Collapse
Affiliation(s)
- Andrew J Borchert
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA; Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Alissa Bleem
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA; Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Gregg T Beckham
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA; Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, USA.
| |
Collapse
|
15
|
Wang G, Li Q, Zhang Z, Yin X, Wang B, Yang X. Recent progress in adaptive laboratory evolution of industrial microorganisms. J Ind Microbiol Biotechnol 2023; 50:kuac023. [PMID: 36323428 PMCID: PMC9936214 DOI: 10.1093/jimb/kuac023] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Accepted: 10/24/2022] [Indexed: 01/12/2023]
Abstract
Adaptive laboratory evolution (ALE) is a technique for the selection of strains with better phenotypes by long-term culture under a specific selection pressure or growth environment. Because ALE does not require detailed knowledge of a variety of complex and interactive metabolic networks, and only needs to simulate natural environmental conditions in the laboratory to design a selection pressure, it has the advantages of broad adaptability, strong practicability, and more convenient transformation of strains. In addition, ALE provides a powerful method for studying the evolutionary forces that change the phenotype, performance, and stability of strains, resulting in more productive industrial strains with beneficial mutations. In recent years, ALE has been widely used in the activation of specific microbial metabolic pathways and phenotypic optimization, the efficient utilization of specific substrates, the optimization of tolerance to toxic substance, and the biosynthesis of target products, which is more conducive to the production of industrial strains with excellent phenotypic characteristics. In this paper, typical examples of ALE applications in the development of industrial strains and the research progress of this technology are reviewed, followed by a discussion of its development prospects.
Collapse
Affiliation(s)
- Guanglu Wang
- Laboratory of Biotransformation and Biocatalysis, School of Tobacco Science and Engineering, Zhengzhou University of Light Industry, Zhengzhou, Henan 450000, People's Republic of China
| | - Qian Li
- Laboratory of Biotransformation and Biocatalysis, School of Tobacco Science and Engineering, Zhengzhou University of Light Industry, Zhengzhou, Henan 450000, People's Republic of China
| | - Zhan Zhang
- Technology Center, China Tobacco Henan Industrial Co., Ltd. Zhengzhou, Henan 450000, People's Republic of China
| | - Xianzhong Yin
- Technology Center, China Tobacco Henan Industrial Co., Ltd. Zhengzhou, Henan 450000, People's Republic of China
| | - Bingyang Wang
- Laboratory of Biotransformation and Biocatalysis, School of Tobacco Science and Engineering, Zhengzhou University of Light Industry, Zhengzhou, Henan 450000, People's Republic of China
| | - Xuepeng Yang
- Laboratory of Biotransformation and Biocatalysis, School of Tobacco Science and Engineering, Zhengzhou University of Light Industry, Zhengzhou, Henan 450000, People's Republic of China
| |
Collapse
|
16
|
Bai W, Anthony WE, Hartline CJ, Wang S, Wang B, Ning J, Hsu FF, Dantas G, Zhang F. Engineering diverse fatty acid compositions of phospholipids in Escherichia coli. Metab Eng 2022; 74:11-23. [PMID: 36058465 DOI: 10.1016/j.ymben.2022.08.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 04/15/2022] [Accepted: 08/26/2022] [Indexed: 11/28/2022]
Abstract
Bacterial fatty acids (FAs) are an essential component of the cellular membrane and are an important source of renewable chemicals as they can be converted to fatty alcohols, esters, ketones, and alkanes, and used as biofuels, detergents, lubricants, and commodity chemicals. Most prior FA bioconversions have been performed on the carboxylic acid group. Modification of the FA hydrocarbon chain could substantially expand the structural and functional diversity of FA-derived products. Additionally, the effects of such modified FAs on the growth and metabolic state of their producing cells are not well understood. Here we engineer novel Escherichia coli phospholipid biosynthetic pathways, creating strains with distinct FA profiles enriched in ω7-unsaturated FAs (ω7-UFAs, 75%), Δ5-unsaturated FAs (Δ5-UFAs, 60%), cyclopropane FAs (CFAs, 55%), internally-branched FAs (IBFAs, 40%), and Δ5,ω7-double unsaturated FAs (DUFAs, 46%). Although bearing drastically different FA profiles in phospholipids, UFA, CFA, and IBFA enriched strains display wild-type-like phenotypic profiling and growth. Transcriptomic analysis reveals DUFA production drives increased differential expression and the induction of the fur iron starvation transcriptional cascade, but higher TCA cycle activation compared to the UFA producing strain. This likely reflects a slight cost imparted for DUFA production, which resulted in lower maximum growth in some, but not all, environmental conditions. The IBFA-enriched strain was further engineered to produce free IBFAs, releasing 96 mg/L free IBFAs from 154 mg/L of the total cellular IBFA pool. This work has resulted in significantly altered FA profiles of membrane lipids in E. coli, greatly increasing our understanding of the effects of FA structure diversity on the transcriptome, growth, and ability to react to stress.
Collapse
Affiliation(s)
- Wenqin Bai
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, Saint Louis, MO, 63130, USA
| | - Winston E Anthony
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine in St. Louis, Saint Louis, MO, 63110, USA
| | - Christopher J Hartline
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, Saint Louis, MO, 63130, USA
| | - Shaojie Wang
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, Saint Louis, MO, 63130, USA
| | - Bin Wang
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine in St. Louis, Saint Louis, MO, 63110, USA; Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, Saint Louis, MO, 63110, USA
| | - Jie Ning
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine in St. Louis, Saint Louis, MO, 63110, USA; Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, Saint Louis, MO, 63110, USA
| | - Fong-Fu Hsu
- Mass Spectrometry Resource, Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Gautam Dantas
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University School of Medicine in St. Louis, Saint Louis, MO, 63110, USA; Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, Saint Louis, MO, 63110, USA; Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, Saint Louis, MO, 63110, USA; Department of Biomedical Engineering, Washington University in St. Louis, Saint Louis, MO, 63130, USA.
| | - Fuzhong Zhang
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, Saint Louis, MO, 63130, USA; Institute of Materials Science & Engineering, Washington University in St. Louis, Saint Louis, MO, 63130, USA.
| |
Collapse
|
17
|
Deciphering the transcriptional regulation of the catabolism of lignin-derived aromatics in Rhodococcus opacus PD630. Commun Biol 2022; 5:1109. [PMID: 36261484 DOI: 10.1038/s42003-022-04069-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Accepted: 10/04/2022] [Indexed: 11/08/2022] Open
Abstract
Rhodococcus opacus PD630 has considerable potential as a platform for valorizing lignin due to its innate "biological funneling" pathways. However, the transcriptional regulation of the aromatic catabolic pathways and the mechanisms controlling aromatic catabolic operons in response to different aromatic mixtures are still underexplored. Here, we identified and studied the transcription factors for aromatic degradation using GFP-based sensors and comprehensive deletion analyses. Our results demonstrate that the funneling pathways for phenol, guaiacol, 4-hydroxybenzoate, and vanillate are controlled by transcriptional activators. The two different branches of the β-ketoadipate pathway, however, are controlled by transcriptional repressors. Additionally, promoter activity assays revealed that the substrate hierarchy in R. opacus may be ascribed to the transcriptional cross-regulation of the individual aromatic funneling pathways. These results provide clues to clarify the molecule-level mechanisms underlying the complex regulation of aromatic catabolism, which facilitates the development of R. opacus as a promising chassis for valorizing lignin.
Collapse
|
18
|
Salusjärvi L, Ojala L, Peddinti G, Lienemann M, Jouhten P, Pitkänen JP, Toivari M. Production of biopolymer precursors beta-alanine and L-lactic acid from CO2 with metabolically versatile Rhodococcus opacus DSM 43205. Front Bioeng Biotechnol 2022; 10:989481. [PMID: 36281430 PMCID: PMC9587121 DOI: 10.3389/fbioe.2022.989481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 09/16/2022] [Indexed: 11/18/2022] Open
Abstract
Hydrogen oxidizing autotrophic bacteria are promising hosts for conversion of CO2 into chemicals. In this work, we engineered the metabolically versatile lithoautotrophic bacterium R. opacus strain DSM 43205 for synthesis of polymer precursors. Aspartate decarboxylase (panD) or lactate dehydrogenase (ldh) were expressed for beta-alanine or L-lactic acid production, respectively. The heterotrophic cultivations on glucose produced 25 mg L−1 beta-alanine and 742 mg L−1 L-lactic acid, while autotrophic cultivations with CO2, H2, and O2 resulted in the production of 1.8 mg L−1 beta-alanine and 146 mg L−1 L-lactic acid. Beta-alanine was also produced at 345 μg L−1 from CO2 in electrobioreactors, where H2 and O2 were provided by water electrolysis. This work demonstrates that R. opacus DSM 43205 can be engineered to produce chemicals from CO2 and provides a base for its further metabolic engineering.
Collapse
Affiliation(s)
- Laura Salusjärvi
- VTT Technical Research Centre of Finland Ltd., Espoo, Finland
- *Correspondence: Laura Salusjärvi,
| | - Leo Ojala
- VTT Technical Research Centre of Finland Ltd., Espoo, Finland
| | - Gopal Peddinti
- VTT Technical Research Centre of Finland Ltd., Espoo, Finland
| | | | - Paula Jouhten
- Department of Bioproducts and Biosystems, Aalto University, Espoo, Finland
| | | | - Mervi Toivari
- VTT Technical Research Centre of Finland Ltd., Espoo, Finland
| |
Collapse
|
19
|
Ivshina I, Bazhutin G, Tyumina E. Rhodococcus strains as a good biotool for neutralizing pharmaceutical pollutants and obtaining therapeutically valuable products: Through the past into the future. Front Microbiol 2022; 13:967127. [PMID: 36246215 PMCID: PMC9557007 DOI: 10.3389/fmicb.2022.967127] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Accepted: 09/12/2022] [Indexed: 11/18/2022] Open
Abstract
Active pharmaceutical ingredients present a substantial risk when they reach the environment and drinking water sources. As a new type of dangerous pollutants with high chemical resistance and pronounced biological effects, they accumulate everywhere, often in significant concentrations (μg/L) in ecological environments, food chains, organs of farm animals and humans, and cause an intense response from the aquatic and soil microbiota. Rhodococcus spp. (Actinomycetia class), which occupy a dominant position in polluted ecosystems, stand out among other microorganisms with the greatest variety of degradable pollutants and participate in natural attenuation, are considered as active agents with high transforming and degrading impacts on pharmaceutical compounds. Many representatives of rhodococci are promising as unique sources of specific transforming enzymes, quorum quenching tools, natural products and novel antimicrobials, biosurfactants and nanostructures. The review presents the latest knowledge and current trends regarding the use of Rhodococcus spp. in the processes of pharmaceutical pollutants’ biodegradation, as well as in the fields of biocatalysis and biotechnology for the production of targeted pharmaceutical products. The current literature sources presented in the review can be helpful in future research programs aimed at promoting Rhodococcus spp. as potential biodegraders and biotransformers to control pharmaceutical pollution in the environment.
Collapse
|
20
|
Jiang W, Gao H, Sun J, Yang X, Jiang Y, Zhang W, Jiang M, Xin F. Current status, challenges and prospects for lignin valorization by using Rhodococcus sp. Biotechnol Adv 2022; 60:108004. [PMID: 35690272 DOI: 10.1016/j.biotechadv.2022.108004] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 05/30/2022] [Accepted: 06/03/2022] [Indexed: 11/18/2022]
Abstract
Lignin represents the most abundant renewable aromatics in nature, which has complicated and heterogeneous structure. The rapid development of biotransformation technology has brought new opportunities to achieve the complete lignin valorization. Especially, Rhodococcus sp. possesses excellent capabilities to metabolize aromatic hydrocarbons degraded from lignin. Furthermore, it can convert these toxic compounds into high value added bioproducts, such as microbial lipids, polyhydroxyalkanoate and carotenoid et al. Accordingly, this review will discuss the potentials of Rhodococcus sp. as a cell factory for lignin biotransformation, including phenol tolerance, lignin depolymerization and lignin-derived aromatic hydrocarbon metabolism. The detailed metabolic mechanism for lignin biotransformation and bioproducts spectrum of Rhodococcus sp. will be comprehensively discussed. The available molecular tools for the conversion of lignin by Rhodococcus sp. will be reviewed, and the possible direction for lignin biotransformation in the future will also be proposed.
Collapse
Affiliation(s)
- Wankui Jiang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, PR China
| | - Haiyan Gao
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, PR China
| | - Jingxiang Sun
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, PR China
| | - Xinyi Yang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, PR China
| | - Yujia Jiang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, PR China
| | - Wenming Zhang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, PR China; Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing 211816, PR China.
| | - Min Jiang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, PR China; Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing 211816, PR China.
| | - Fengxue Xin
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, PR China; Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing 211816, PR China.
| |
Collapse
|
21
|
Mueller J, Willett H, Feist AM, Niu W. Engineering Pseudomonas putida for Improved Utilization of Syringyl Aromatics. Biotechnol Bioeng 2022; 119:2541-2550. [PMID: 35524438 PMCID: PMC9378539 DOI: 10.1002/bit.28131] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 04/22/2022] [Accepted: 05/01/2022] [Indexed: 11/08/2022]
Abstract
Lignin is a largely untapped source for the bioproduction of value‐added chemicals. Pseudomonas putida KT2440 has emerged as a strong candidate for bioprocessing of lignin feedstocks due to its resistance to several industrial solvents, broad metabolic capabilities, and genetic amenability. Here we demonstrate the engineering of P. putida for the ability to metabolize syringic acid, one of the major products that comes from the breakdown of the syringyl component of lignin. The rational design was first applied for the construction of strain Sy‐1 by overexpressing a native vanillate demethylase. Subsequent adaptive laboratory evolution (ALE) led to the generation of mutations that achieved robust growth on syringic acid as a sole carbon source. The best mutant showed a 30% increase in the growth rate over the original engineered strain. Genomic sequencing revealed multiple mutations repeated in separate evolved replicates. Reverse engineering of mutations identified in agmR, gbdR, fleQ, and the intergenic region of gstB and yadG into the parental strain recaptured the improved growth of the evolved strains to varied extent. These findings thus reveal the ability of P. putida to utilize lignin more fully as a feedstock and make it a more economically viable chassis for chemical production.
Collapse
Affiliation(s)
- Joshua Mueller
- Department of Chemical and Biomolecular Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska, 68588, United States
| | - Howard Willett
- Department of Chemical and Biomolecular Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska, 68588, United States
| | - Adam M Feist
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, USA.,Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
| | - Wei Niu
- Department of Chemical and Biomolecular Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska, 68588, United States.,The Nebraska Center for Integrated Biomolecular Communication (NCIBC), University of Nebraska-Lincoln, Lincoln, Nebraska, 68588, United States
| |
Collapse
|
22
|
Yu C, Wang H, Blaustein RA, Guo L, Ye Q, Fu Y, Fan J, Su X, Hartmann EM, Shen C. Pangenomic and functional investigations for dormancy and biodegradation features of an organic pollutant-degrading bacterium Rhodococcus biphenylivorans TG9. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 809:151141. [PMID: 34688761 DOI: 10.1016/j.scitotenv.2021.151141] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Revised: 10/14/2021] [Accepted: 10/18/2021] [Indexed: 06/13/2023]
Abstract
Environmental bacteria contain a wealth of untapped potential in the form of biodegradative genes. Leveraging this potential can often be confounded by a lack of understanding of fundamental survival strategies, like dormancy, for environmental stress. Investigating bacterial dormancy-to-degradation relationships enables improvement of bioremediation. Here, we couple genomic and functional assessment to provide context for key attributes of the organic pollutant-degrading strain Rhodococcus biphenylivorans TG9. Whole genome sequencing, pangenome analysis and functional characterization were performed to elucidate important genes and gene products, including antimicrobial resistance, dormancy, and degradation. Rhodococcus as a genus has strong potential for degradation and dormancy, which we demonstrate using R. biphenylivorans TG9 as a model. We identified four Resuscitation-promoting factor (Rpf) encoding genes in TG9 involved in dormancy and resuscitation. We demonstrate that R. biphenylivorans TG9 grows on fourteen typical organic pollutants, and exhibits a robust ability to degrade biphenyl and several congeners of polychlorinated biphenyls. We further induced TG9 into a dormant state and demonstrated pronounced differences in morphology and activity. Together, these results expand our understanding of the genus Rhodococcus and the relationship between dormancy and biodegradation in the presence of environmental stressors.
Collapse
Affiliation(s)
- Chungui Yu
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Hui Wang
- College of Eco-Environmental Engineering, Guizhou Minzu University, Guiyang, Guizhou, China; Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Ryan Andrew Blaustein
- Department of Civil and Environmental Engineering, Northwestern University, Evanston, IL, USA
| | - Li Guo
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Qi Ye
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Yulong Fu
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Jiahui Fan
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xiaomei Su
- College of Geography and Environmental Science, Zhejiang Normal University, Jinhua, Zhejiang, China; Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Erica Marie Hartmann
- Department of Civil and Environmental Engineering, Northwestern University, Evanston, IL, USA.
| | - Chaofeng Shen
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, Zhejiang, China.
| |
Collapse
|
23
|
CRISPR-based metabolic engineering in non-model microorganisms. Curr Opin Biotechnol 2022; 75:102698. [PMID: 35217297 DOI: 10.1016/j.copbio.2022.102698] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 01/20/2022] [Accepted: 02/07/2022] [Indexed: 12/13/2022]
Abstract
Non-model microorganisms possess unique and versatile metabolic characteristics, offering great opportunities as cell factories for biosynthesis of target products. However, lack of efficient genetic tools for pathway engineering represents a big challenge to unlock the full production potential of these microbes. Over the past years, CRISPR systems have been extensively developed and applied to domesticate non-model microorganisms. In this paper, we summarize the current significant advances in designing and constructing CRISPR-mediated genetic modification systems in non-model microorganisms, such as bacteria, fungi and cyanobacteria. We particularly put emphasis on reviewing some successful implementations in metabolic pathway engineering via CRISPR-based genome editing tools. Moreover, the current barriers and future perspectives on improving the editing efficiency of CRISPR systems in non-model microorganisms are also discussed.
Collapse
|
24
|
Firrincieli A, Grigoriev B, Dostálová H, Cappelletti M. The Complete Genome Sequence and Structure of the Oleaginous Rhodococcus opacus Strain PD630 Through Nanopore Technology. Front Bioeng Biotechnol 2022; 9:810571. [PMID: 35252163 PMCID: PMC8892189 DOI: 10.3389/fbioe.2021.810571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Accepted: 12/27/2021] [Indexed: 11/19/2022] Open
Affiliation(s)
- Andrea Firrincieli
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
| | - Beatrice Grigoriev
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
| | | | - Martina Cappelletti
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
- *Correspondence: Martina Cappelletti,
| |
Collapse
|
25
|
Weiland F, Kohlstedt M, Wittmann C. Guiding stars to the field of dreams: Metabolically engineered pathways and microbial platforms for a sustainable lignin-based industry. Metab Eng 2021; 71:13-41. [PMID: 34864214 DOI: 10.1016/j.ymben.2021.11.011] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 11/25/2021] [Accepted: 11/29/2021] [Indexed: 12/19/2022]
Abstract
Lignin is an important structural component of terrestrial plants and is readily generated during biomass fractionation in lignocellulose processing facilities. Due to lacking alternatives the majority of technical lignins is industrially simply burned into heat and energy. However, regarding its vast abundance and a chemically interesting richness in aromatics, lignin is presently regarded as the most under-utilized and promising feedstock for value-added applications. Notably, microbes have evolved powerful enzymes and pathways that break down lignin and metabolize its various aromatic components. This natural pathway atlas meanwhile serves as a guiding star for metabolic engineers to breed designed cell factories and efficiently upgrade this global waste stream. The metabolism of aromatic compounds, in combination with success stories from systems metabolic engineering, as reviewed here, promises a sustainable product portfolio from lignin, comprising bulk and specialty chemicals, biomaterials, and fuels.
Collapse
Affiliation(s)
- Fabia Weiland
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | - Michael Kohlstedt
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | - Christoph Wittmann
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany.
| |
Collapse
|
26
|
Ahmad M, Wang P, Li JL, Wang R, Duan L, Luo X, Irfan M, Peng Z, Yin L, Li WJ. Impacts of bio-stimulants on pyrene degradation, prokaryotic community compositions, and functions. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 289:117863. [PMID: 34352636 DOI: 10.1016/j.envpol.2021.117863] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 07/26/2021] [Accepted: 07/27/2021] [Indexed: 06/13/2023]
Abstract
Bio-stimulation of the indigenous microbial community is considered as an effective strategy for the bioremediation of polluted environments. This examination explored the near effects of various bio-stimulants on pyrene degradation, prokaryotic community compositions, and functions using 16S rRNA amplicon sequencing and qPCR. At first, the results displayed significant differences (p < 0.05) between the prokaryotic community structures of the control group, PYR (contains pyrene only), and bio-stimulants amended groups. Among the bio-stimulants, biochar, oxalic acid, salicylate, NPK, and ammonium sulfate augmented the pyrene degradation potential of microbial communities. Moreover, the higher abundance of genera, such as Flavobacterium, Hydrogenophaga, Mycobacterium, Rhodococcus, Flavihumibacter, Pseudomonas, Novosphingobium, etc., across the treatments indicated that these genera play a vital role in pyrene metabolism. Based on the higher abundance of GP-RHD and nidA genes, we speculated that Gram-positive prokaryotic communities are more competent in pyrene dissipation than Gram-negative. Furthermore, the marked abundance of nifH, and pqqC genes in the NPK and SA treatments, respectively, suggested that different bio-stimulants might enrich certain bacterial assemblages. Besides, the significant distinctions (p < 0.05) between the bacterial consortia of HA (humic acid) and SA (sodium acetate) groups from NPK, OX (oxalic acid), UR (urea), NH4, and SC (salicylate) groups also suggested that different bio-stimulants might induce distinct ecological impacts influencing the succession of prokaryotic communities in distinct directions. This work provides new insight into the bacterial degradation of pyrene using the bio-stimulation technique. It suggests that it is equally important to investigate the community structure and functions along with studying their impacts on degradation when devising a bio-stimulation technology.
Collapse
Affiliation(s)
- Manzoor Ahmad
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, PR China
| | - Pandeng Wang
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, PR China
| | - Jia-Ling Li
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, PR China
| | - Renfei Wang
- Division of Biosciences, University College London, Gower Street, London, WC1E 6BT, UK
| | - Li Duan
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, PR China
| | - Xiaoqing Luo
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, PR China
| | - Muhammad Irfan
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, FL, United States
| | - Ziqi Peng
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, PR China
| | - Lingzi Yin
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, PR China
| | - Wen-Jun Li
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, PR China; State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, PR China.
| |
Collapse
|
27
|
Azubuike CC, Allemann MN, Michener JK. Microbial assimilation of lignin-derived aromatic compounds and conversion to value-added products. Curr Opin Microbiol 2021; 65:64-72. [PMID: 34775172 DOI: 10.1016/j.mib.2021.10.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 10/19/2021] [Accepted: 10/21/2021] [Indexed: 11/03/2022]
Abstract
Lignin is an abundant and sustainable source of aromatic compounds that can be converted to value-added products. However, lignin is underutilized, since depolymerization produces a complex mixture of aromatic compounds that is difficult to convert to a single product. Microbial conversion of mixed aromatic substrates provides a potential solution to this conversion challenge. Recent advances have expanded the range of lignin-derived aromatic substrates that can be assimilated and demonstrated efficient conversion via central metabolism to new potential products. The development of additional non-model microbial hosts and genetic tools for these hosts have accelerated engineering efforts. However, yields with real depolymerized lignin are still low, and additional work will be required to achieve viable conversion processes.
Collapse
Affiliation(s)
| | - Marco N Allemann
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Joshua K Michener
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA.
| |
Collapse
|
28
|
Donini E, Firrincieli A, Cappelletti M. Systems biology and metabolic engineering of Rhodococcus for bioconversion and biosynthesis processes. Folia Microbiol (Praha) 2021; 66:701-713. [PMID: 34215934 PMCID: PMC8449775 DOI: 10.1007/s12223-021-00892-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 06/12/2021] [Indexed: 11/04/2022]
Abstract
Rhodococcus spp. strains are widespread in diverse natural and anthropized environments thanks to their high metabolic versatility, biodegradation activities, and unique adaptation capacities to several stress conditions such as the presence of toxic compounds and environmental fluctuations. Additionally, the capability of Rhodococcus spp. strains to produce high value-added products has received considerable attention, mostly in relation to lipid accumulation. In relation with this, several works carried out omic studies and genome comparative analyses to investigate the genetic and genomic basis of these anabolic capacities, frequently in association with the bioconversion of renewable resources and low-cost substrates into triacylglycerols. This review is focused on these omic analyses and the genetic and metabolic approaches used to improve the biosynthetic and bioconversion performance of Rhodococcus. In particular, this review summarizes the works that applied heterologous expression of specific genes and adaptive laboratory evolution approaches to manipulate anabolic performance. Furthermore, recent molecular toolkits for targeted genome editing as well as genome-based metabolic models are described here as novel and promising strategies for genome-scaled rational design of Rhodococcus cells for efficient biosynthetic processes application.
Collapse
Affiliation(s)
- Eva Donini
- Department of Pharmacy and Biotechnology, University of Bologna, Via Irnerio 42, 40126, Bologna, Italy
| | - Andrea Firrincieli
- Department of Pharmacy and Biotechnology, University of Bologna, Via Irnerio 42, 40126, Bologna, Italy
| | - Martina Cappelletti
- Department of Pharmacy and Biotechnology, University of Bologna, Via Irnerio 42, 40126, Bologna, Italy.
| |
Collapse
|
29
|
Cai C, Xu Z, Zhou H, Chen S, Jin M. Valorization of lignin components into gallate by integrated biological hydroxylation, O-demethylation, and aryl side-chain oxidation. SCIENCE ADVANCES 2021; 7:eabg4585. [PMID: 34516898 PMCID: PMC8442903 DOI: 10.1126/sciadv.abg4585] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Converting lignin components into a single product is a promising way to upgrade lignin. Here, an efficient biocatalyst was developed to selectively produce gallate from lignin components by integrating three main reactions: hydroxylation, O-demethylation, and aryl side-chain oxidation. A rationally designed hydroxylase system was first introduced into a gallate biodegradation pathway–blocked Rhodococcus opacus mutant so that gallate accumulated from protocatechuate and compounds in its upper pathways. Native and heterologous O-demethylation systems were then used, leading to multiple lignin-derived methoxy aromatics being converted to gallate. Furthermore, an aryl side-chain oxidase was engaged to broaden the substrate spectrum. Consequently, the developed biocatalyst showed that gallate yields as high as 0.407 and 0.630 g of gallate per gram of lignin when alkaline-pretreated lignin and base-depolymerized ammonia fiber explosion lignin were applied as substrates, respectively. These results suggested that this rationally developed biocatalyst enabled the lignin valorization process to be simple and efficient.
Collapse
Affiliation(s)
- Chenggu Cai
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, 200 Xiaolingwei Street, Nanjing 210094, China
| | - Zhaoxian Xu
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, 200 Xiaolingwei Street, Nanjing 210094, China
| | - Huarong Zhou
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, 200 Xiaolingwei Street, Nanjing 210094, China
| | - Sitong Chen
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, 200 Xiaolingwei Street, Nanjing 210094, China
| | - Mingjie Jin
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, 200 Xiaolingwei Street, Nanjing 210094, China
- Corresponding author.
| |
Collapse
|
30
|
Henson WR, Meyers AW, Jayakody LN, DeCapite A, Black BA, Michener WE, Johnson CW, Beckham GT. Biological upgrading of pyrolysis-derived wastewater: Engineering Pseudomonas putida for alkylphenol, furfural, and acetone catabolism and (methyl)muconic acid production. Metab Eng 2021; 68:14-25. [PMID: 34438073 DOI: 10.1016/j.ymben.2021.08.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Revised: 08/18/2021] [Accepted: 08/22/2021] [Indexed: 10/20/2022]
Abstract
While biomass-derived carbohydrates have been predominant substrates for biological production of renewable fuels, chemicals, and materials, organic waste streams are growing in prominence as potential alternative feedstocks to improve the sustainability of manufacturing processes. Catalytic fast pyrolysis (CFP) is a promising approach to generate biofuels from lignocellulosic biomass, but it generates a complex, carbon-rich, and toxic wastewater stream that is challenging to process catalytically but could be biologically upgraded to valuable co-products. In this work, we implemented modular, heterologous catabolic pathways in the Pseudomonas putida KT2440-derived EM42 strain along with the overexpression of native toxicity tolerance machinery to enable utilization of 89% (w/w) of carbon in CFP wastewater. The dmp monooxygenase and meta-cleavage pathway from Pseudomonas putida CF600 were constitutively expressed to enable utilization of phenol, cresols, 2- and 3-ethyl phenol, and methyl catechols, and the native chaperones clpB, groES, and groEL were overexpressed to improve toxicity tolerance to diverse aromatic substrates. Next, heterologous furfural and acetone utilization pathways were incorporated, and a native alcohol dehydrogenase was overexpressed to improve methanol utilization, generating reducing equivalents. All pathways (encoded by genes totaling ~30 kilobases of DNA) were combined into a single strain that can catabolize a mock CFP wastewater stream as a sole carbon source. Further engineering enabled conversion of all aromatic compounds in the mock wastewater stream to (methyl)muconates with a ~90% (mol/mol) yield. Biological upgrading of CFP wastewater as outlined in this work provides a roadmap for future applications in valorizing other heterogeneous waste streams.
Collapse
Affiliation(s)
- William R Henson
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Alex W Meyers
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Lahiru N Jayakody
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Annette DeCapite
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Brenna A Black
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - William E Michener
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Christopher W Johnson
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA.
| | - Gregg T Beckham
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA.
| |
Collapse
|
31
|
Liang Y, Wei Y, Jiao S, Yu H. A CRISPR/Cas9-based single-stranded DNA recombineering system for genome editing of Rhodococcus opacus PD630. Synth Syst Biotechnol 2021; 6:200-208. [PMID: 34430726 PMCID: PMC8365321 DOI: 10.1016/j.synbio.2021.08.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 07/13/2021] [Accepted: 08/02/2021] [Indexed: 12/01/2022] Open
Abstract
Genome engineering of Rhodococcus opacus PD630, an important microorganism used for the bioconversion of lignin, is currently dependent on inefficient homologous recombination. Although a CRISPR interference procedure for gene repression has previously been developed for R. opacus PD630, a CRISPR/Cas9 system for gene knockout has yet to be reported for the strain. In this study, we found that the cytotoxicity of Cas9 and the deficiency in pathways for repairing DNA double-strand breaks (DSBs) were the major causes of the failure of conventional CRISPR/Cas9 technologies in R. opacus, even when augmented with the recombinases Che9c60 and Che9c61. We successfully developed an efficient single-stranded DNA (ssDNA) recombineering system coupled with CRISPR/Cas9 counter-selection, which facilitated rapid and scarless editing of the R. opacus genome. A two-plasmid system, comprising Cas9 driven by a weak Rhodococcus promoter Pniami, designed to prevent cytotoxicity, and a single-guide RNA (sgRNA) under the control of a strong constitutive promoter, was proven to be appropriate with respect to cleavage function. A novel recombinase, RrRecT derived from a Rhodococcus ruber prophage, was identified for the first time, which facilitated recombination of short ssDNA donors (40–80 nt) targeted to the lagging strand and enabled us to obtain a recombination efficiency up to 103-fold higher than that of endogenous pathways. Finally, by incorporating RrRecT and Cas9 into a single plasmid and then co-transforming cells with sgRNA plasmids and short ssDNA donors, we efficiently achieved gene disruption and base mutation in R. opacus, with editing efficiencies ranging from 22 % to 100 %. Simultaneous disruption of double genes was also confirmed, although at a lower efficiency. This effective genome editing tool will accelerate the engineering of R. opacus metabolism.
Collapse
Affiliation(s)
- Youxiang Liang
- Department of Chemical Engineering, Tsinghua University, Beijing, 100084, China.,Key Laboratory of Industrial Biocatalysis (Tsinghua University), The Ministry of Education, Beijing, 100084, China
| | - Yuwen Wei
- Department of Chemical Engineering, Tsinghua University, Beijing, 100084, China.,Key Laboratory of Industrial Biocatalysis (Tsinghua University), The Ministry of Education, Beijing, 100084, China
| | - Song Jiao
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea
| | - Huimin Yu
- Department of Chemical Engineering, Tsinghua University, Beijing, 100084, China.,Key Laboratory of Industrial Biocatalysis (Tsinghua University), The Ministry of Education, Beijing, 100084, China.,Center for Synthetic and Systems Biology, Tsinghua University, Beijing, 100084, China
| |
Collapse
|
32
|
Challenges and opportunities in biological funneling of heterogeneous and toxic substrates beyond lignin. Curr Opin Biotechnol 2021; 73:1-13. [PMID: 34242853 DOI: 10.1016/j.copbio.2021.06.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 06/02/2021] [Accepted: 06/07/2021] [Indexed: 12/12/2022]
Abstract
Significant developments in the understanding and manipulation of microbial metabolism have enabled the use of engineered biological systems toward a more sustainable energy and materials economy. While developments in metabolic engineering have primarily focused on the conversion of carbohydrates, substantial opportunities exist for using these same principles to extract value from more heterogeneous and toxic waste streams, such as those derived from lignin, biomass pyrolysis, or industrial waste. Funneling heterogeneous substrates from these streams toward valuable products, termed biological funneling, presents new challenges in balancing multiple catabolic pathways competing for shared cellular resources and engineering against perturbation from toxic substrates. Solutions to many of these challenges have been explored within the field of lignin valorization. This perspective aims to extend beyond lignin to highlight the challenges and discuss opportunities for use of biological systems to upgrade previously inaccessible waste streams.
Collapse
|
33
|
DeLorenzo DM, Diao J, Carr R, Hu Y, Moon TS. An Improved CRISPR Interference Tool to Engineer Rhodococcus opacus. ACS Synth Biol 2021; 10:786-798. [PMID: 33787248 DOI: 10.1021/acssynbio.0c00591] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Rhodococcus opacus is a nonmodel bacterium that is well suited for valorizing lignin. Despite recent advances in our systems-level understanding of its versatile metabolism, studies of its gene functions at a single gene level are still lagging. Elucidating gene functions in nonmodel organisms is challenging due to limited genetic engineering tools that are convenient to use. To address this issue, we developed a simple gene repression system based on CRISPR interference (CRISPRi). This gene repression system uses a T7 RNA polymerase system to express a small guide RNA, demonstrating improved repression compared to the previously demonstrated CRISPRi system (i.e., the maximum repression efficiency improved from 58% to 85%). Additionally, our cloning strategy allows for building multiple CRISPRi plasmids in parallel without any PCR step, facilitating the engineering of this GC-rich organism. Using the improved CRISPRi system, we confirmed the annotated roles of four metabolic pathway genes, which had been identified by our previous transcriptomic analysis to be related to the consumption of benzoate, vanillate, catechol, and acetate. Furthermore, we showed our tool's utility by demonstrating the inducible accumulation of muconate that is a precursor of adipic acid, an important monomer for nylon production. While the maximum muconate yield obtained using our tool was 30% of the yield obtained using gene knockout, our tool showed its inducibility and partial repressibility. Our CRISPRi tool will be useful to facilitate functional studies of this nonmodel organism and engineer this promising microbial chassis for lignin valorization.
Collapse
Affiliation(s)
- Drew M. DeLorenzo
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Jinjin Diao
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Rhiannon Carr
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Yifeng Hu
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Tae Seok Moon
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
- Division of Biology and Biomedical Sciences, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| |
Collapse
|
34
|
Liang Y, Yu H. Genetic toolkits for engineering Rhodococcus species with versatile applications. Biotechnol Adv 2021; 49:107748. [PMID: 33823269 DOI: 10.1016/j.biotechadv.2021.107748] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Revised: 03/31/2021] [Accepted: 03/31/2021] [Indexed: 02/09/2023]
Abstract
Rhodococcus spp. are a group of non-model gram-positive bacteria with diverse catabolic activities and strong adaptive capabilities, which enable their wide application in whole-cell biocatalysis, environmental bioremediation, and lignocellulosic biomass conversion. Compared with model microorganisms, the engineering of Rhodococcus is challenging because of the lack of universal molecular tools, high genome GC content (61% ~ 71%), and low transformation and recombination efficiencies. Nevertheless, because of the high interest in Rhodococcus species for bioproduction, various genetic elements and engineering tools have been recently developed for Rhodococcus spp., including R. opacus, R. jostii, R. ruber, and R. erythropolis, leading to the expansion of the genetic toolkits for Rhodococcus engineering. In this article, we provide a comprehensive review of the important developed genetic elements for Rhodococcus, including shuttle vectors, promoters, antibiotic markers, ribosome binding sites, and reporter genes. In addition, we also summarize gene transfer techniques and strategies to improve transformation efficiency, as well as random and precise genome editing tools available for Rhodococcus, including transposition, homologous recombination, recombineering, and CRISPR/Cas9. We conclude by discussing future trends in Rhodococcus engineering. We expect that more synthetic and systems biology tools (such as multiplex genome editing, dynamic regulation, and genome-scale metabolic models) will be adapted and optimized for Rhodococcus.
Collapse
Affiliation(s)
- Youxiang Liang
- Department of Chemical Engineering, Tsinghua University, Beijing 100084, China; Key Laboratory of Industrial Biocatalysis (Tsinghua University), the Ministry of Education, Beijing 100084, China
| | - Huimin Yu
- Department of Chemical Engineering, Tsinghua University, Beijing 100084, China; Key Laboratory of Industrial Biocatalysis (Tsinghua University), the Ministry of Education, Beijing 100084, China; Center for Synthetic and Systems Biology, Tsinghua University, Beijing 100084, China.
| |
Collapse
|
35
|
Yaguchi AL, Lee SJ, Blenner MA. Synthetic Biology towards Engineering Microbial Lignin Biotransformation. Trends Biotechnol 2021; 39:1037-1064. [PMID: 33712323 DOI: 10.1016/j.tibtech.2021.02.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 02/03/2021] [Accepted: 02/03/2021] [Indexed: 01/19/2023]
Abstract
Lignin is the second most abundant biopolymer on earth and is a major source of aromatic compounds; however, it is vastly underutilized owing to its heterogeneous and recalcitrant nature. Microorganisms have evolved efficient mechanisms that overcome these challenges to depolymerize lignin and funnel complex mixtures of lignin-derived monomers to central metabolites. This review summarizes recent synthetic biology efforts to enhance lignin depolymerization and aromatic catabolism in bacterial and fungal hosts for the production of both natural and novel bioproducts. We also highlight difficulties in engineering complex phenotypes and discuss the outlook for the future of lignin biological valorization.
Collapse
Affiliation(s)
- Allison L Yaguchi
- Department of Chemical and Biomolecular Engineering, Clemson University, 206 South Palmetto Boulevard, Clemson, SC 29634, USA
| | - Stephen J Lee
- Department of Chemical and Biomolecular Engineering, Clemson University, 206 South Palmetto Boulevard, Clemson, SC 29634, USA
| | - Mark A Blenner
- Department of Chemical and Biomolecular Engineering, Clemson University, 206 South Palmetto Boulevard, Clemson, SC 29634, USA; Current address: Department of Chemical and Biomolecular Engineering, University of Delaware, 590 Avenue 1743, Newark, DE 19713, USA.
| |
Collapse
|
36
|
Cappelletti M, Presentato A, Piacenza E, Firrincieli A, Turner RJ, Zannoni D. Biotechnology of Rhodococcus for the production of valuable compounds. Appl Microbiol Biotechnol 2020; 104:8567-8594. [PMID: 32918579 PMCID: PMC7502451 DOI: 10.1007/s00253-020-10861-z] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 08/14/2020] [Accepted: 08/26/2020] [Indexed: 12/31/2022]
Abstract
Bacteria belonging to Rhodococcus genus represent ideal candidates for microbial biotechnology applications because of their metabolic versatility, ability to degrade a wide range of organic compounds, and resistance to various stress conditions, such as metal toxicity, desiccation, and high concentration of organic solvents. Rhodococcus spp. strains have also peculiar biosynthetic activities that contribute to their strong persistence in harsh and contaminated environments and provide them a competitive advantage over other microorganisms. This review is focused on the metabolic features of Rhodococcus genus and their potential use in biotechnology strategies for the production of compounds with environmental, industrial, and medical relevance such as biosurfactants, bioflocculants, carotenoids, triacylglycerols, polyhydroxyalkanoate, siderophores, antimicrobials, and metal-based nanostructures. These biosynthetic capacities can also be exploited to obtain high value-added products from low-cost substrates (industrial wastes and contaminants), offering the possibility to efficiently recover valuable resources and providing possible waste disposal solutions. Rhodococcus spp. strains have also recently been pointed out as a source of novel bioactive molecules highlighting the need to extend the knowledge on biosynthetic capacities of members of this genus and their potential utilization in the framework of bioeconomy. KEY POINTS: • Rhodococcus possesses promising biosynthetic and bioconversion capacities. • Rhodococcus bioconversion capacities can provide waste disposal solutions. • Rhodococcus bioproducts have environmental, industrial, and medical relevance. Graphical abstract.
Collapse
Affiliation(s)
- Martina Cappelletti
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Bologna, Italy.
| | - Alessandro Presentato
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Palermo, Italy
| | - Elena Piacenza
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Palermo, Italy
- National Interuniversity Consortium of Materials Science and Technology (INSTM), Florence, Italy
| | - Andrea Firrincieli
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Bologna, Italy
| | - Raymond J Turner
- Department of Biological Sciences, Calgary University, Calgary, AB, Canada
| | - Davide Zannoni
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Bologna, Italy
| |
Collapse
|
37
|
Characterization of alkylguaiacol-degrading cytochromes P450 for the biocatalytic valorization of lignin. Proc Natl Acad Sci U S A 2020; 117:25771-25778. [PMID: 32989155 DOI: 10.1073/pnas.1916349117] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Cytochrome P450 enzymes have tremendous potential as industrial biocatalysts, including in biological lignin valorization. Here, we describe P450s that catalyze the O-demethylation of lignin-derived guaiacols with different ring substitution patterns. Bacterial strains Rhodococcus rhodochrous EP4 and Rhodococcus jostii RHA1 both utilized alkylguaiacols as sole growth substrates. Transcriptomics of EP4 grown on 4-propylguaiacol (4PG) revealed the up-regulation of agcA, encoding a CYP255A1 family P450, and the aph genes, previously shown to encode a meta-cleavage pathway responsible for 4-alkylphenol catabolism. The function of the homologous pathway in RHA1 was confirmed: Deletion mutants of agcA and aphC, encoding the meta-cleavage alkylcatechol dioxygenase, grew on guaiacol but not 4PG. By contrast, deletion mutants of gcoA and pcaL, encoding a CYP255A2 family P450 and an ortho-cleavage pathway enzyme, respectively, grew on 4-propylguaiacol but not guaiacol. CYP255A1 from EP4 catalyzed the O-demethylation of 4-alkylguaiacols to 4-alkylcatechols with the following apparent specificities (k cat/K M): propyl > ethyl > methyl > guaiacol. This order largely reflected AgcA's binding affinities for the different guaiacols and was the inverse of GcoAEP4's specificities. The biocatalytic potential of AgcA was demonstrated by the ability of EP4 to grow on lignin-derived products obtained from the reductive catalytic fractionation of corn stover, depleting alkylguaiacols and alkylphenols. By identifying related P450s with complementary specificities for lignin-relevant guaiacols, this study facilitates the design of these enzymes for biocatalytic applications. We further demonstrated that the metabolic fate of the guaiacol depends on its substitution pattern, a finding that has significant implications for engineering biocatalysts to valorize lignin.
Collapse
|
38
|
Chatterjee A, DeLorenzo DM, Carr R, Moon TS. Bioconversion of renewable feedstocks by Rhodococcus opacus. Curr Opin Biotechnol 2020; 64:10-16. [DOI: 10.1016/j.copbio.2019.08.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 08/19/2019] [Accepted: 08/25/2019] [Indexed: 12/18/2022]
|
39
|
Tailoring microbes to upgrade lignin. Curr Opin Chem Biol 2020; 59:23-29. [PMID: 32388219 DOI: 10.1016/j.cbpa.2020.04.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Revised: 03/31/2020] [Accepted: 04/01/2020] [Indexed: 12/16/2022]
Abstract
Lignin depolymerization generates a mixture of numerous compounds that are difficult to separate cost-effectively. To address this heterogeneity issue, microbes have been employed to 'biologically funnel' a broad range of compounds present in depolymerized lignin into common central metabolites that can be converted into a single desirable product. Because the composition of depolymerized lignin varies significantly with the type of biomass and the depolymerization method, microbes should be selected and engineered by considering this compositional variation. An ideal microbe must efficiently metabolize all relevant lignin-derived compounds regardless of the compositional variation of feedstocks, but discovering or developing such a perfect microbe is very challenging. Instead, developing multiple tailored microbes to tolerate a given mixture of lignin-derived compounds and to convert most of these into a target product is more practical. This review summarizes recent progress toward the development of such microbes for lignin valorization and offers future directions.
Collapse
|
40
|
Yaguchi A, Franaszek N, O'Neill K, Lee S, Sitepu I, Boundy-Mills K, Blenner M. Identification of oleaginous yeasts that metabolize aromatic compounds. J Ind Microbiol Biotechnol 2020; 47:801-813. [PMID: 32221720 DOI: 10.1007/s10295-020-02269-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 02/29/2020] [Indexed: 01/02/2023]
Abstract
The valorization of lignin is critical for the economic viability of the bioeconomy. Microbial metabolism is advantageous for handling the myriad of aromatic compounds resulting from lignin chemical or enzymatic depolymerization. Coupling aromatic metabolism to fatty acid biosynthesis makes possible the production of biofuels, oleochemicals, and other fine/bulk chemicals derived from lignin. Our previous work identified Cutaneotrichosporon oleaginosus as a yeast that could accumulate nearly 70% of its dry cell weight as lipids using aromatics as a sole carbon source. Expanding on this, other oleaginous yeast species were investigated for the metabolism of lignin-relevant monoaromatics. Thirty-six oleaginous yeast species from the Phaff yeast collection were screened for growth on several aromatic compounds representing S-, G-, and H- type lignin. The analysis reported in this study suggests that aromatic metabolism is largely segregated to the Cutaenotrichosporon, Trichosporon, and Rhodotorula clades. Each species tested within each clade has different properties with respect to the aromatics metabolized and the concentrations of aromatics tolerated. The combined analysis suggests that Cutaneotrichosporon yeast are the best suited to broad spectrum aromatic metabolism and support its development as a model system for aromatic metabolism in yeast.
Collapse
Affiliation(s)
- Allison Yaguchi
- Department of Chemical and Biomolecular Engineering, Clemson University, 206 S. Palmetto Blvd, Clemson, SC, 29634, USA
| | - Nicole Franaszek
- Department of Chemical and Biomolecular Engineering, Clemson University, 206 S. Palmetto Blvd, Clemson, SC, 29634, USA
| | - Kaelyn O'Neill
- Department of Chemical and Biomolecular Engineering, Clemson University, 206 S. Palmetto Blvd, Clemson, SC, 29634, USA
| | - Stephen Lee
- Department of Chemical and Biomolecular Engineering, Clemson University, 206 S. Palmetto Blvd, Clemson, SC, 29634, USA
| | - Irnayuli Sitepu
- Phaff Yeast Culture Collection, Food Science and Technology, University of California Davis, One Shields Ave, Davis, CA, 95616, USA
| | - Kyria Boundy-Mills
- Phaff Yeast Culture Collection, Food Science and Technology, University of California Davis, One Shields Ave, Davis, CA, 95616, USA
| | - Mark Blenner
- Department of Chemical and Biomolecular Engineering, Clemson University, 206 S. Palmetto Blvd, Clemson, SC, 29634, USA.
| |
Collapse
|
41
|
Liang Y, Jiao S, Wang M, Yu H, Shen Z. A CRISPR/Cas9-based genome editing system for Rhodococcus ruber TH. Metab Eng 2020; 57:13-22. [DOI: 10.1016/j.ymben.2019.10.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 10/10/2019] [Accepted: 10/10/2019] [Indexed: 02/03/2023]
|
42
|
Becker J, Wittmann C. A field of dreams: Lignin valorization into chemicals, materials, fuels, and health-care products. Biotechnol Adv 2019; 37:107360. [DOI: 10.1016/j.biotechadv.2019.02.016] [Citation(s) in RCA: 207] [Impact Index Per Article: 41.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 02/18/2019] [Accepted: 02/22/2019] [Indexed: 02/07/2023]
|
43
|
Roell GW, Carr RR, Campbell T, Shang Z, Henson WR, Czajka JJ, Martín HG, Zhang F, Foston M, Dantas G, Moon TS, Tang YJ. A concerted systems biology analysis of phenol metabolism in Rhodococcus opacus PD630. Metab Eng 2019; 55:120-130. [DOI: 10.1016/j.ymben.2019.06.013] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 06/19/2019] [Accepted: 06/30/2019] [Indexed: 01/28/2023]
|
44
|
DeLorenzo DM, Moon TS. Construction of Genetic Logic Gates Based on the T7 RNA Polymerase Expression System in Rhodococcus opacus PD630. ACS Synth Biol 2019; 8:1921-1930. [PMID: 31362487 DOI: 10.1021/acssynbio.9b00213] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Rhodococcus opacus PD630 (R. opacus) is a nonmodel, Gram-positive bacterium that holds promise as a biological catalyst for the conversion of lignocellulosic biomass to value-added products. In particular, it demonstrates both a high tolerance for and an ability to consume inhibitory lignin-derived aromatics, generates large quantities of lipids, exhibits a relatively rapid growth rate, and has a growing genetic toolbox for engineering. However, the availability of genetic parts for tunable, high-activity gene expression is still limited in R. opacus. Furthermore, genetic logic circuits for sophisticated gene regulation have never been demonstrated in Rhodococcus spp. To address these shortcomings, two inducible T7 RNA polymerase-based expression systems were implemented for the first time in R. opacus and applied to the construction of AND and NAND genetic logic gates. Additionally, three isopropyl β-d-1-thiogalactopyranoside (IPTG)-inducible promoters were created by inserting LacI binding sites into newly characterized constitutive promoters. Furthermore, four novel aromatic sensors for 4-hydroxybenzoic acid, vanillic acid, sodium benzoate, and guaiacol were developed, expanding the gene expression toolbox. Finally, the T7 RNA polymerase platform was combined with a synthetic IPTG-inducible promoter to create an IMPLY logic gate. Overall, this work represents the first demonstration of a heterologous RNA polymerase system and synthetic genetic logic in R. opacus, enabling complex and tunable gene regulation in this promising nonmodel host for bioproduction.
Collapse
Affiliation(s)
- Drew M. DeLorenzo
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Tae Seok Moon
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
- Division of Biology and Biomedical Sciences, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| |
Collapse
|
45
|
Sandberg TE, Salazar MJ, Weng LL, Palsson BO, Feist AM. The emergence of adaptive laboratory evolution as an efficient tool for biological discovery and industrial biotechnology. Metab Eng 2019; 56:1-16. [PMID: 31401242 DOI: 10.1016/j.ymben.2019.08.004] [Citation(s) in RCA: 262] [Impact Index Per Article: 52.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 08/01/2019] [Accepted: 08/05/2019] [Indexed: 12/21/2022]
Abstract
Harnessing the process of natural selection to obtain and understand new microbial phenotypes has become increasingly possible due to advances in culturing techniques, DNA sequencing, bioinformatics, and genetic engineering. Accordingly, Adaptive Laboratory Evolution (ALE) experiments represent a powerful approach both to investigate the evolutionary forces influencing strain phenotypes, performance, and stability, and to acquire production strains that contain beneficial mutations. In this review, we summarize and categorize the applications of ALE to various aspects of microbial physiology pertinent to industrial bioproduction by collecting case studies that highlight the multitude of ways in which evolution can facilitate the strain construction process. Further, we discuss principles that inform experimental design, complementary approaches such as computational modeling that help maximize utility, and the future of ALE as an efficient strain design and build tool driven by growing adoption and improvements in automation.
Collapse
Affiliation(s)
- Troy E Sandberg
- Department of Bioengineering, University of California, San Diego, CA, 92093, USA
| | - Michael J Salazar
- Department of Bioengineering, University of California, San Diego, CA, 92093, USA
| | - Liam L Weng
- Department of Bioengineering, University of California, San Diego, CA, 92093, USA
| | - Bernhard O Palsson
- Department of Bioengineering, University of California, San Diego, CA, 92093, USA; Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800, Lyngby, Denmark
| | - Adam M Feist
- Department of Bioengineering, University of California, San Diego, CA, 92093, USA; Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800, Lyngby, Denmark.
| |
Collapse
|
46
|
Brink DP, Ravi K, Lidén G, Gorwa-Grauslund MF. Mapping the diversity of microbial lignin catabolism: experiences from the eLignin database. Appl Microbiol Biotechnol 2019; 103:3979-4002. [PMID: 30963208 PMCID: PMC6486533 DOI: 10.1007/s00253-019-09692-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 02/06/2019] [Accepted: 02/09/2019] [Indexed: 12/18/2022]
Abstract
Lignin is a heterogeneous aromatic biopolymer and a major constituent of lignocellulosic biomass, such as wood and agricultural residues. Despite the high amount of aromatic carbon present, the severe recalcitrance of the lignin macromolecule makes it difficult to convert into value-added products. In nature, lignin and lignin-derived aromatic compounds are catabolized by a consortia of microbes specialized at breaking down the natural lignin and its constituents. In an attempt to bridge the gap between the fundamental knowledge on microbial lignin catabolism, and the recently emerging field of applied biotechnology for lignin biovalorization, we have developed the eLignin Microbial Database ( www.elignindatabase.com ), an openly available database that indexes data from the lignin bibliome, such as microorganisms, aromatic substrates, and metabolic pathways. In the present contribution, we introduce the eLignin database, use its dataset to map the reported ecological and biochemical diversity of the lignin microbial niches, and discuss the findings.
Collapse
Affiliation(s)
- Daniel P Brink
- Applied Microbiology, Department of Chemistry, Lund University, P.O. Box 124, SE-221 00, Lund, Sweden.
| | - Krithika Ravi
- Department of Chemical Engineering, Lund University, Lund, Sweden
| | - Gunnar Lidén
- Department of Chemical Engineering, Lund University, Lund, Sweden
| | - Marie F Gorwa-Grauslund
- Applied Microbiology, Department of Chemistry, Lund University, P.O. Box 124, SE-221 00, Lund, Sweden
| |
Collapse
|
47
|
Anthony WE, Carr RR, DeLorenzo DM, Campbell TP, Shang Z, Foston M, Moon TS, Dantas G. Development of Rhodococcus opacus as a chassis for lignin valorization and bioproduction of high-value compounds. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:192. [PMID: 31404385 PMCID: PMC6683499 DOI: 10.1186/s13068-019-1535-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 07/24/2019] [Indexed: 05/09/2023]
Abstract
The current extraction and use of fossil fuels has been linked to extensive negative health and environmental outcomes. Lignocellulosic biomass-derived biofuels and bioproducts are being actively considered as renewable alternatives to the fuels, chemicals, and materials produced from fossil fuels. A major challenge limiting large-scale, economic deployment of second-generation biorefineries is the insufficient product yield, diversity, and value that current conversion technologies can extract from lignocellulose, in particular from the underutilized lignin fraction. Rhodococcus opacus PD630 is an oleaginous gram-positive bacterium with innate catabolic pathways and tolerance mechanisms for the inhibitory aromatic compounds found in depolymerized lignin, as well as native or engineered pathways for hexose and pentose sugars found in the carbohydrate fractions of biomass. As a result, R. opacus holds potential as a biological chassis for the conversion of lignocellulosic biomass into biodiesel precursors and other value-added products. This review begins by examining the important role that lignin utilization will play in the future of biorefineries and by providing a concise survey of the current lignin conversion technologies. The genetic machinery and capabilities of R. opacus that allow the bacterium to tolerate and metabolize aromatic compounds and depolymerized lignin are also discussed, along with a synopsis of the genetic toolbox and synthetic biology methods now available for engineering this organism. Finally, we summarize the different feedstocks that R. opacus has been demonstrated to consume, and the high-value products that it has been shown to produce. Engineered R. opacus will enable lignin valorization over the coming years, leading to cost-effective conversion of lignocellulose into fuels, chemicals, and materials.
Collapse
Affiliation(s)
- Winston E. Anthony
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University in St. Louis School of Medicine, St. Louis, MO 63110 USA
| | - Rhiannon R. Carr
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO 63130 USA
| | - Drew M. DeLorenzo
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO 63130 USA
| | - Tayte P. Campbell
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University in St. Louis School of Medicine, St. Louis, MO 63110 USA
| | - Zeyu Shang
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO 63130 USA
| | - Marcus Foston
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO 63130 USA
| | - Tae Seok Moon
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO 63130 USA
| | - Gautam Dantas
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University in St. Louis School of Medicine, St. Louis, MO 63110 USA
- Department of Pathology and Immunology, Washington University in St. Louis School of Medicine, St. Louis, MO 63108 USA
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130 USA
- Department of Molecular Microbiology, Washington University in St. Louis School of Medicine, St. Louis, MO 63108 USA
| |
Collapse
|