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Liang J, Chen Y, Li S, Liu D, Tian H, Xiang Q, Zhao K, Yu X, Chen Q, Fan H, Zhang L, Penttinen P, Gu Y. Transcriptomic analysis and carbohydrate metabolism-related enzyme expression across different pH values in Rhizopus delemar. Front Microbiol 2024; 15:1359830. [PMID: 38511010 PMCID: PMC10953822 DOI: 10.3389/fmicb.2024.1359830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 02/22/2024] [Indexed: 03/22/2024] Open
Abstract
Introduction pH is one of the important factors affecting the growth and performance of microorganisms. Methods We studied the pH response and plant growth-promoting (PGP) ability of Rhizopus delemar using cultivation experiments and transcriptomics, and verified the expression profiles using quantitative real-time PCR. Results pH affected the growth and PGP properties of R. delemar. At pH 7, the growth rate of R. delemar was rapid, whereas pH 4 and 8 inhibited mycelial growth and PGP ability, respectively. In the pot experiment, the plant height was the highest at pH 7, 56 cm, and the lowest at pH 4 and pH 5, 46.6 cm and 47 cm, respectively. Enzyme activities were highest at pH 6 to pH 7. Enzyme activities were highest at pH 6 to pH 7. Among the 1,629 differentially expressed genes (DEGs), 1,033 genes were up-regulated and 596 were down-regulated. A total of 1,623 DEGs were annotated to carbohydrate-active enzyme coding genes. Discussion The PGP characteristics, e.g., Phosphorus solubilization ability, of R. delemar were strongest at pH 7. The results provide useful information regarding the molecular mechanism of R. delemar pH response.
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Affiliation(s)
- Jinpeng Liang
- Department of Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Yulan Chen
- Department of Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
- Liangshan Tobacco Corporation of Sichuan Province, Xichang, China
| | - Sisi Li
- Department of Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Dongyang Liu
- Department of Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
- Liangshan Tobacco Corporation of Sichuan Province, Xichang, China
| | - Hong Tian
- Department of Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Quanju Xiang
- Department of Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Ke Zhao
- Department of Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Xiumei Yu
- Department of Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Qiang Chen
- Department of Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Hongzhu Fan
- Institute of Agricultural Resources and Environmental Science, Sichuan Academy of Agricultural Sciences, Chengdu, China
| | - Lingzi Zhang
- Department of Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Petri Penttinen
- Department of Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Yunfu Gu
- Department of Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
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Luo Y, Yan X, Xia Y, Cao Y. Tetracarboxylic acid transporter regulates growth, conidiation, and carbon utilization in Metarhizium acridum. Appl Microbiol Biotechnol 2023; 107:2969-2982. [PMID: 36941435 DOI: 10.1007/s00253-023-12471-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 02/25/2023] [Accepted: 02/28/2023] [Indexed: 03/23/2023]
Abstract
Carbon sources and their utilization are vital for fungal growth and development. C4-dicarboxylic acids are important carbon and energy sources that function as intermediate products of the tricarboxylic acid cycle. Transport and regulation of C4-dicarboxylic acid uptake are mainly dependent on tetracarboxylic acid transporters (Dcts) in many microbes, although the roles of Dct genes in fungi have only been partially characterized. Here, we report on the functions of two Dct genes (Dct1 and Dct2) in the entomopathogenic fungus Metarhizium acridum. Our data showed that loss of the MaDct1 gene affected utilization of tetracarboxylic acids and other carbon sources. ΔMaDct1 mutants showed larger colony sizes with extensive mycelial growth but were delayed in conidiation with decreased conidia yield as compared to the wild-type parental strain. On the nutrient-deficient medium, SYA, the wild-type strain produced microcycle conidia, whereas the ΔMaDct1 mutant produced (normal) aerial conidia. In addition, ΔMaDct1 had decreased tolerance to cell wall perturbing agents, but increased tolerances to UV-B radiation and osmotic stress. Insect bioassays indicated that loss of MaDct1 did not affect pathogenicity. In contrast, no distinct phenotypic change was observed for the MaDct2 mutant in terms of growth and biocontrol characteristics. Transcriptomic profiling between wild type and ΔMaDct1 showed that differentially expressed genes were enriched in carbohydrate and amino acid metabolism, transport and catabolism, and signal transduction. These results demonstrate that MaDct1 regulates the conidiation pattern shift and mycelial growth by affecting utilization of carbon sources. These findings are helpful for better understanding the effect of intermediates of carbon metabolism on fungal growth and conidiation. KEY POINTS: • MaDct1 influences fungal growth and conidiation by affecting carbon source utilization. • MaDct1 regulates conidiation pattern shift under nutrient deficiency condition. • MaDct1 is involved in stress tolerance and has no effect on virulence. • MaDct2 has no effect on growth and biocontrol characteristic.
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Affiliation(s)
- Yunxiao Luo
- School of Life Sciences, Chongqing University, Chongqing, 401331, People's Republic of China
- Chongqing Engineering Research Center for Fungal Insecticides, Chongqing, 401331, People's Republic of China
- Key Laboratory of Gene Function and Regulation Technologies Under Chongqing Municipal Education Commission, Chongqing, China
| | - Xi Yan
- School of Life Sciences, Chongqing University, Chongqing, 401331, People's Republic of China
- Chongqing Engineering Research Center for Fungal Insecticides, Chongqing, 401331, People's Republic of China
- Key Laboratory of Gene Function and Regulation Technologies Under Chongqing Municipal Education Commission, Chongqing, China
| | - Yuxian Xia
- School of Life Sciences, Chongqing University, Chongqing, 401331, People's Republic of China.
- Chongqing Engineering Research Center for Fungal Insecticides, Chongqing, 401331, People's Republic of China.
- Key Laboratory of Gene Function and Regulation Technologies Under Chongqing Municipal Education Commission, Chongqing, China.
| | - Yueqing Cao
- School of Life Sciences, Chongqing University, Chongqing, 401331, People's Republic of China.
- Chongqing Engineering Research Center for Fungal Insecticides, Chongqing, 401331, People's Republic of China.
- Key Laboratory of Gene Function and Regulation Technologies Under Chongqing Municipal Education Commission, Chongqing, China.
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Letourneau DR, Volmer DA. Mass spectrometry-based methods for the advanced characterization and structural analysis of lignin: A review. MASS SPECTROMETRY REVIEWS 2023; 42:144-188. [PMID: 34293221 DOI: 10.1002/mas.21716] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Revised: 06/23/2021] [Accepted: 06/28/2021] [Indexed: 06/13/2023]
Abstract
Lignin is currently one of the most promising biologically derived resources, due to its abundance and application in biofuels, materials and conversion to value aromatic chemicals. The need to better characterize and understand this complex biopolymer has led to the development of many different analytical approaches, several of which involve mass spectrometry and subsequent data analysis. This review surveys the most important analytical methods for lignin involving mass spectrometry, first looking at methods involving gas chromatography, liquid chromatography and then continuing with more contemporary methods such as matrix assisted laser desorption ionization and time-of-flight-secondary ion mass spectrometry. Following that will be techniques that directly ionize lignin mixtures-without chromatographic separation-using softer atmospheric ionization techniques that leave the lignin oligomers intact. Finally, ultra-high resolution mass analyzers such as FT-ICR have enabled lignin analysis without major sample preparation and chromatography steps. Concurrent with an increase in the resolution of mass spectrometers, there have been a wealth of complementary data analyses and visualization methods that have allowed researchers to probe deeper into the "lignome" than ever before. These approaches extract trends such as compound series and even important analytical information about lignin substructures without performing lignin degradation either chemically or during MS analysis. These innovative methods are paving the way for a more comprehensive understanding of this important biopolymer, as we seek more sustainable solutions for our human species' energy and materials needs.
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Affiliation(s)
- Dane R Letourneau
- Department of Chemistry, Humboldt University Berlin, Berlin, Germany
| | - Dietrich A Volmer
- Department of Chemistry, Humboldt University Berlin, Berlin, Germany
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Wu Z, Peng K, Zhang Y, Wang M, Yong C, Chen L, Qu P, Huang H, Sun E, Pan M. Lignocellulose dissociation with biological pretreatment towards the biochemical platform: A review. Mater Today Bio 2022; 16:100445. [PMID: 36212906 PMCID: PMC9535326 DOI: 10.1016/j.mtbio.2022.100445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 09/24/2022] [Accepted: 09/27/2022] [Indexed: 11/30/2022]
Abstract
Lignocellulose utilization has been gaining great attention worldwide due to its abundance, accessibility, renewability and recyclability. Destruction and dissociation of the cross-linked, hierarchical structure within cellulose hemicellulose and lignin is the key procedure during chemical utilization of lignocellulose. Of the pretreatments, biological treatment, which can effectively target the complex structures, is attractive due to its mild reaction conditions and environmentally friendly characteristics. Herein, we report a comprehensive review of the current biological pretreatments for lignocellulose dissociation and their corresponding degradation mechanisms. Firstly, we analyze the layered, hierarchical structure of cell wall, and the cross-linked network between cellulose, hemicellulose and lignin, then highlight that the cracking of β-aryl ether is considered the key to lignin degradation because of its dominant position. Secondly, we explore the effect of biological pretreatments, such as fungi, bacteria, microbial consortium, and enzymes, on substrate structure and degradation efficiency. Additionally, combining biological pretreatment with other methods (chemical methods and catalytic materials) may reduce the time necessary for the whole process, which also help to strengthen the lignocellulose dissociation efficiency. Thirdly, we summarize the related applications of lignocellulose, such as fuel production, chemicals platform, and bio-pulping, which could effectively alleviate the energy pressure through bioconversion into high value-added products. Based on reviewing of current progress of lignocellulose pretreatment, the challenges and future prospects are emphasized. Genetic engineering and other technologies to modify strains or enzymes for improved biotransformation efficiency will be the focus of future research.
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Affiliation(s)
- Zengyou Wu
- College of Materials Science and Engineering, Nanjing Forestry University, Nanjing, 210037, China
- Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization/Key Laboratory of Saline-Alkali Soil Improvement and Utilization (Coastal Saline-Alkali Lands), Ministry of Agriculture and Rural Affairs/Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China
| | - Kun Peng
- School of Agricultural Engineering, Jiangsu University, Zhenjiang, 212013, China
| | - Yin Zhang
- College of Materials Science and Engineering, Nanjing Forestry University, Nanjing, 210037, China
| | - Mei Wang
- School of Agricultural Engineering, Jiangsu University, Zhenjiang, 212013, China
| | - Cheng Yong
- Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization/Key Laboratory of Saline-Alkali Soil Improvement and Utilization (Coastal Saline-Alkali Lands), Ministry of Agriculture and Rural Affairs/Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China
| | - Ling Chen
- Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization/Key Laboratory of Saline-Alkali Soil Improvement and Utilization (Coastal Saline-Alkali Lands), Ministry of Agriculture and Rural Affairs/Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China
| | - Ping Qu
- Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization/Key Laboratory of Saline-Alkali Soil Improvement and Utilization (Coastal Saline-Alkali Lands), Ministry of Agriculture and Rural Affairs/Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China
| | - Hongying Huang
- Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization/Key Laboratory of Saline-Alkali Soil Improvement and Utilization (Coastal Saline-Alkali Lands), Ministry of Agriculture and Rural Affairs/Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China
| | - Enhui Sun
- Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization/Key Laboratory of Saline-Alkali Soil Improvement and Utilization (Coastal Saline-Alkali Lands), Ministry of Agriculture and Rural Affairs/Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China
- School of Agricultural Engineering, Jiangsu University, Zhenjiang, 212013, China
- College of Agriculture, Engineering and Science, University of KwaZulu-Natal (Pietermaritzburg Campus), Private Bag X01, Scottsville, 3209, South Africa
- Corresponding author. Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization/Key Laboratory of Saline-Alkali Soil Improvement and Utilization (Coastal Saline-Alkali Lands), Ministry of Agriculture and Rural Affairs/Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China.
| | - Mingzhu Pan
- College of Materials Science and Engineering, Nanjing Forestry University, Nanjing, 210037, China
- Corresponding author.
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Vuong TV, Singh R, Eltis LD, Master ER. The Comparative Abilities of a Small Laccase and a Dye-Decoloring Peroxidase From the Same Bacterium to Transform Natural and Technical Lignins. Front Microbiol 2021; 12:723524. [PMID: 34733245 PMCID: PMC8559727 DOI: 10.3389/fmicb.2021.723524] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 09/23/2021] [Indexed: 11/29/2022] Open
Abstract
The relative ability of the small laccase (sLac) and dye-decoloring peroxidase (DyP2) from Amycolatopsis sp. 75iv2 to transform a variety of lignins was investigated using time-of-flight secondary ion mass spectrometry (ToF-SIMS). The enzymes modified organosolv hardwood lignin to different extents even in the absence of an added mediator. More particularly, sLac decreased the lignin modification metric S (S-lignin)/Ar (total aromatics) by 58% over 16h, while DyP2 lowered this ratio by 31% in the absence of exogenous H2O2. When used on their own, both sLac and DyP2 also modified native lignin present in aspen wood powder, albeit to lesser extents than in the organosolv lignin. The addition of ABTS for sLac and Mn2+ as well as H2O2 for DyP2 led to increased lignin modification in aspen wood powder as reflected by a decrease in the G/Ar metric by up to a further 13%. This highlights the importance of exogenous mediators for transforming lignin within its native matrix. Furthermore, the addition of ABTS reduced the selectivity of sLac for S-lignin over G-lignin, indicating that the mediator also altered the product profiles. Finally, when sLac was included in reactions containing DyP2, in part to generate H2O2in situ, the relative abundance of lignin products differed from individual enzymatic treatments. Overall, these results identify possible routes to tuning lignin modification or delignification through choice of enzyme and mediator. Moreover, the current study expands the application of ToF-SIMS to evaluating enzyme action on technical lignins, which can accelerate the discovery and engineering of industrially relevant enzymes for lignin valorization.
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Affiliation(s)
- Thu V Vuong
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada
| | - Rahul Singh
- Department of Microbiology and Immunology, BioProducts Institute, The University of British Columbia, Vancouver, BC, Canada.,Genome British Columbia, Vancouver, BC, Canada
| | - Lindsay D Eltis
- Department of Microbiology and Immunology, BioProducts Institute, The University of British Columbia, Vancouver, BC, Canada
| | - Emma R Master
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada.,Department of Bioproducts and Biosystems, Aalto University, Espoo, Finland
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Evolution of Fungal Carbohydrate-Active Enzyme Portfolios and Adaptation to Plant Cell-Wall Polymers. J Fungi (Basel) 2021; 7:jof7030185. [PMID: 33807546 PMCID: PMC7998857 DOI: 10.3390/jof7030185] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 02/25/2021] [Accepted: 02/25/2021] [Indexed: 12/21/2022] Open
Abstract
The postindustrial era is currently facing two ecological challenges. First, the rise in global temperature, mostly caused by the accumulation of carbon dioxide (CO2) in the atmosphere, and second, the inability of the environment to absorb the waste of human activities. Fungi are valuable levers for both a reduction in CO2 emissions, and the improvement of a circular economy with the optimized valorization of plant waste and biomass. Soil fungi may promote plant growth and thereby increase CO2 assimilation via photosynthesis or, conversely, they may prompt the decomposition of dead organic matter, and thereby contribute to CO2 emissions. The strategies that fungi use to cope with plant-cell-wall polymers and access the saccharides that they use as a carbon source largely rely on the secretion of carbohydrate-active enzymes (CAZymes). In the past few years, comparative genomics and phylogenomics coupled with the functional characterization of CAZymes significantly improved the understanding of their evolution in fungal genomes, providing a framework for the design of nature-inspired enzymatic catalysts. Here, we provide an overview of the diversity of CAZyme enzymatic systems employed by fungi that exhibit different substrate preferences, different ecologies, or belong to different taxonomical groups for lignocellulose degradation.
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7
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Huang X, Zhang R, Qiu Y, Wu H, Xiang Q, Yu X, Zhao K, Zhang X, Chen Q, Penttinen P, Gu Y. RNA-seq Profiling Showed Divergent Carbohydrate-Active Enzymes (CAZymes) Expression Patterns in Lentinula edodes at Brown Film Formation Stage Under Blue Light Induction. Front Microbiol 2020; 11:1044. [PMID: 32536907 PMCID: PMC7267012 DOI: 10.3389/fmicb.2020.01044] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 04/27/2020] [Indexed: 12/12/2022] Open
Abstract
Lentinula edodes (shiitake mushroom) is one of the most important edible mushrooms worldwide. The L. edodes cultivation cycle includes a unique developing stage called brown film formation that directly affects the development of primordium and the quality of fruiting body. Brown film formation is induced by light, especially blue light. To promote our understanding of the role of blue light in brown film formation mechanisms of L. edodes, we used RNA-seq and compared the transcriptomes of L. edodes grown under blue light and in dark, and validated the expression profiles using qRT-PCR. Blue light stimulated the formation of brown film and increased the content of polysaccharides in L. edodes. Blue light also promoted L. edodes to absorb more polysaccharides by enhancing the activities of enzymes. Among the 730 differentially expressed genes (DEGs), 433 genes were up-regulated and 297 were down-regulated. Most of the DEGs were in the oxidoreductase activity group. Pentose and glucuronic acid conversion and starch and sucrose metabolism were the most important pathways in the formation of brown film. A total of 79 genes of DEGs were identified as genes encoding carbohydrate-active enzymes (CAZymes). Fifty-one of the CAZymes genes were up-regulated, suggesting that CAZymes play important roles in brown film formation to provide sufficient nutrition for L. edodes. The results will facilitate future functional investigations of the genes involved in the developmental control of L. edodes.
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Affiliation(s)
- Xiying Huang
- Department of Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Runji Zhang
- Department of Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Yijie Qiu
- Department of Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Haibing Wu
- Department of Livestock and Fisheries, Mianyang Academy of Agricultural University, Mianyang, China
| | - Quanju Xiang
- Department of Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Xiumei Yu
- Department of Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Ke Zhao
- Department of Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Xiaoping Zhang
- Department of Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Qiang Chen
- Department of Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Petri Penttinen
- Department of Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
| | - Yunfu Gu
- Department of Microbiology, College of Resources, Sichuan Agricultural University, Chengdu, China
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Goacher RE, Braham EJ, Michienzi CL, Flick RM, Yakunin AF, Master ER. Direct analysis by time-of-flight secondary ion mass spectrometry reveals action of bacterial laccase-mediator systems on both hardwood and softwood samples. PHYSIOLOGIA PLANTARUM 2018; 164:5-16. [PMID: 29286544 DOI: 10.1111/ppl.12688] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Revised: 12/20/2017] [Accepted: 12/26/2017] [Indexed: 06/07/2023]
Abstract
The modification and degradation of lignin play a vital role in carbon cycling as well as production of biofuels and bioproducts. The possibility of using bacterial laccases for the oxidation of lignin offers a route to utilize existing industrial protein expression techniques. However, bacterial laccases are most frequently studied on small model compounds that do not capture the complexity of lignocellulosic materials. This work studied the action of laccases from Bacillus subtilis and Salmonella typhimurium (EC 1.10.3.2) on ground wood samples from yellow birch (Betula alleghaniensis) and red spruce (Picea rubens). The ability of bacterial laccases to modify wood can be facilitated by small molecule mediators. Herein, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), gallic acid and sinapic acid mediators were tested. Direct analysis of the wood samples was achieved by time-of-flight secondary ion mass spectrometry (ToF-SIMS), a surface sensitive mass spectrometry technique that has characteristic peaks for H, G and S lignin. The action of the bacterial laccases on both wood samples was demonstrated and revealed a strong mediator influence. The ABTS mediator led to delignification, evident in an overall increase of polysaccharide peaks in the residual solid, along with equal loss of G and S-lignin peaks. The gallic acid mediator demonstrated minimal laccase activity. Meanwhile, the sinapic acid mediator altered the S/G peak ratio consistent with mediator attaching to the wood solids. The current investigation demonstrates the action of bacterial laccase-mediator systems directly on woody materials, and the potential of using ToF-SIMS to uncover the fundamental and applied role of bacterial enzymes in lignocellulose conversion.
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Affiliation(s)
- Robyn E Goacher
- Department of Biochemistry, Chemistry and Physics, Niagara University, 5795 Lewiston Road, Lewiston, NY, 14109, USA
| | - Erick J Braham
- Department of Biochemistry, Chemistry and Physics, Niagara University, 5795 Lewiston Road, Lewiston, NY, 14109, USA
- Department of Chemistry, Texas A&M University, 580 Ross Street, College Station, TX, 77843, USA
| | - Courtney L Michienzi
- Department of Biochemistry, Chemistry and Physics, Niagara University, 5795 Lewiston Road, Lewiston, NY, 14109, USA
| | - Robert M Flick
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario, M5S 3E5, Canada
| | - Alexander F Yakunin
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario, M5S 3E5, Canada
| | - Emma R Master
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario, M5S 3E5, Canada
- Department of Bioproducts and Biosystems, Aalto University, FI-00076 Aalto, Kemistintie 1, Espoo, Finland
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Cuesta S, Arias J, Gallegos F, Alzate-Morales J, Meneses L. On the Reaction Mechanism of the 3,4-Dimethoxybenzaldehyde Formation from 1-(3',4'-Dimethoxyphenyl)Propene. Molecules 2018; 23:E412. [PMID: 29443875 PMCID: PMC6017041 DOI: 10.3390/molecules23020412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 01/25/2018] [Accepted: 01/29/2018] [Indexed: 11/17/2022] Open
Abstract
Lignin peroxidase (LiP) is an important enzyme for degrading aromatic hydrocarbons not only in nature but also in industry. In the presence of H₂O₂, this enzyme can easily decompose lignin and analogue compounds under mild conditions. In this reaction mechanism, LiP catalyzes the C-C cleavage of a propenyl side chain, being able to produce veratraldehyde (VAD) from 1-(3',4'-dimethoxyphenyl) propene (DMPP). One of the few and complete proposed mechanisms includes several non-enzymatic reactions. In this study, we performed a computational study to gain insight about the non-enzymatic steps involved in the reaction mechanism of VAD formation from DMPP using LiP as a catalyst. A kinetic characterization of the reaction using the reaction force and the reaction force constant concepts within the density functional theory (DFT) framework is proposed. All theoretical calculations for the reaction pathway were performed using the Minnesota Global Hybrid functional M06-2X and a 6-31++G(d,p) basis set. The complete reaction comprises seven steps (five steps not including LiP as a catalyst), which include radical species formation, bond transformation, water and oxygen addition, atom reordering, and deacetylation. The overall mechanism is an endothermic process with mixed activation energies depending on the four transition states. These results are the first attempt to fully understand the catalytic role of LiP in the degradation of lignin and its aromatic derivative compounds in terms of the electronic structure methods and future hybrid calculation approaches that we have recently been performing.
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Affiliation(s)
- Sebastián Cuesta
- Chemistry Department, Pontifical Catholic University of Equator, Av. 12 de Octubre 1076 y Roca, Quito 170109, Ecuador.
| | - Josefa Arias
- Chemistry Department, Pontifical Catholic University of Equator, Av. 12 de Octubre 1076 y Roca, Quito 170109, Ecuador.
| | - Felipe Gallegos
- Chemistry Department, Pontifical Catholic University of Equator, Av. 12 de Octubre 1076 y Roca, Quito 170109, Ecuador.
| | - Jans Alzate-Morales
- Center for Bioinformatics and Molecular Simulations, Faculty of Engineering, University of Talca, 2 Norte 685, Casilla 721, Talca 3640000, Chile.
| | - Lorena Meneses
- Chemistry Department, Pontifical Catholic University of Equator, Av. 12 de Octubre 1076 y Roca, Quito 170109, Ecuador.
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10
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Goacher RE, Michienzi CL. How does soaking wood in various pH buffers impact ToF-SIMS spectra? SURF INTERFACE ANAL 2017. [DOI: 10.1002/sia.6354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Abstract
The global push toward an efficient and economical biobased economy has driven research to develop more cost-effective applications for the entirety of plant biomass, including lignocellulosic crops. As discussed elsewhere (Karlsson M, Atanasova L, Funck Jensen D, Zeilinger S, in Heitman J et al. [ed], Tuberculosis and the Tubercle Bacillus, 2nd ed, in press), significant progress has been made in the use of polysaccharide fractions from lignocellulose, cellulose, and various hemicellulose types. However, developing processes for use of the lignin fraction has been more challenging. In this chapter, we discuss characteristics of lignolytic enzymes and the fungi that produce them as well as potential and current uses of lignin-derived products.
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