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Rodriguez A, Hirakawa MP, Geiselman GM, Tran-Gyamfi MB, Light YK, George A, Sale KL. Prospects for utilizing microbial consortia for lignin conversion. FRONTIERS IN CHEMICAL ENGINEERING 2023. [DOI: 10.3389/fceng.2023.1086881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Naturally occurring microbial communities are able to decompose lignocellulosic biomass through the concerted production of a myriad of enzymes that degrade its polymeric components and assimilate the resulting breakdown compounds by members of the community. This process includes the conversion of lignin, the most recalcitrant component of lignocellulosic biomass and historically the most difficult to valorize in the context of a biorefinery. Although several fundamental questions on microbial conversion of lignin remain unanswered, it is known that some fungi and bacteria produce enzymes to break, internalize, and assimilate lignin-derived molecules. The interest in developing efficient biological lignin conversion approaches has led to a better understanding of the types of enzymes and organisms that can act on different types of lignin structures, the depolymerized compounds that can be released, and the products that can be generated through microbial biosynthetic pathways. It has become clear that the discovery and implementation of native or engineered microbial consortia could be a powerful tool to facilitate conversion and valorization of this underutilized polymer. Here we review recent approaches that employ isolated or synthetic microbial communities for lignin conversion to bioproducts, including the development of methods for tracking and predicting the behavior of these consortia, the most significant challenges that have been identified, and the possibilities that remain to be explored in this field.
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Alves TA, Pinheiro PF, Praça-Fontes MM, Andrade-Vieira LF, Lourenço MP, Lage MR, Alves TA, Cruz FA, Carneiro JWM, Ferreira A, Soares TCB. Bioactivity and molecular properties of Phenoxyacetic Acids Derived from Eugenol and Guaiacol compared to the herbicide 2,4-D. AN ACAD BRAS CIENC 2021; 93:e20191368. [PMID: 34705933 DOI: 10.1590/0001-3765202120191368] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 07/16/2020] [Indexed: 11/22/2022] Open
Abstract
Herbicides are agrochemicals applied in the control of weeds. With the frequent and repetitive use of these substances, serious problems have been reported. Compounds of natural origin and their derivatives are attractive options to obtain new compounds with herbicidal properties. By aiming to develop compounds with potentiated herbicidal activity, phenoxyacetic acids were synthesized from eugenol and guaiacol. The synthesized compounds were characterized and the herbicidal potential of phenoxyacetic acids and precursors was evaluated through bioassays regarding the germination and initial development of Lactuca sativa and Sorghum bicolor seedlings, with the induction of DNA damage. The induction of changes in the mitotic cycle of meristematic cells of roots of L. sativa was also analyzed. At the concentration of 3 mmol L-1, phenols and their respective phenoxyacetic acids presented phytotoxic and cytotoxic activities in L. sativa and S. bicolor. Eugenol and guaiacol also presented genotoxic action in L. sativa. The toxic effect of eugenoxyacetic acid was more pronounced in L. sativa than in S. bicolor, similar to the commercial 2,4-D herbicide. Molecular properties of the phenols and their derivatives phenoxyacetic acids were compared with the ones obtained for the herbicide 2,4-D, where it was found a correlation between their molecular properties and bioactivity.
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Affiliation(s)
- Thammyres A Alves
- Programa de Pós-Graduação em Genética e Melhoramento da Universidade Federal do Espírito Santo, Alto Universitário, s/n, 29500-000 Alegre, ES, Brazil
| | - Patrícia F Pinheiro
- Universidade Federal de Viçosa, Departamento de Química, Avenida Peter Henry Rolfs, Campus Universitário, s/n, 36570-900 Viçosa, MG, Brazil
| | - Milene M Praça-Fontes
- Programa de Pós-Graduação em Genética e Melhoramento da Universidade Federal do Espírito Santo, Alto Universitário, s/n, 29500-000 Alegre, ES, Brazil.,Universidade Federal do Espírito Santo, Centro de Ciências Exatas, Naturais e da Saúde, Departamento de Biologia, Alto Universitário, s/n, 29500-000 Alegre, ES, Brazil
| | - Larissa F Andrade-Vieira
- Universidade Federal de Lavras, Departamento de Biologia, Aquenta Sol, s/n, 37200-000 Lavras, MG, Brazil
| | - Maicon P Lourenço
- Universidade Federal do Espírito Santo, Centro de Ciências Exatas, Naturais e da Saúde, Departamento de Química e Física, Alto Universitário, s/n, 29500-000 Alegre, ES, Brazil
| | - Mateus R Lage
- Programa de Pós-Graduação em Ciência dos Materiais, Universidade Federal do Maranhão, Centro de Ciências Sociais, Saúde e Tecnologia, Rua Urbano Santos, 1734, 65900-410 Imperatriz, MA, Brazil.,Universidade Federal do Maranhão, Campus Balsas, MA-140, Km 04, Centro, 65800-000 Balsas, MA, Brazil
| | - Thayllon A Alves
- Universidade Federal do Espírito Santo, Centro de Ciências Agrárias e Engenharias, Departamento de Agronomia, Alto Universitário, s/n, 29500-000 Alegre, ES, Brazil
| | - Franceli A Cruz
- Universidade Federal de Lavras, Departamento de Biologia, Aquenta Sol, s/n, 37200-000 Lavras, MG, Brazil
| | - José W M Carneiro
- Universidade Federal Fluminense, Departamento de Química Inorgânica, Outeiro São João Batista, s/n, 24020-141 Niterói, RJ, Brazil
| | - Adésio Ferreira
- Universidade Federal do Espírito Santo, Centro de Ciências Agrárias e Engenharias, Departamento de Agronomia, Alto Universitário, s/n, 29500-000 Alegre, ES, Brazil
| | - Taís C B Soares
- Programa de Pós-Graduação em Genética e Melhoramento da Universidade Federal do Espírito Santo, Alto Universitário, s/n, 29500-000 Alegre, ES, Brazil.,Universidade Federal do Espírito Santo, Centro de Ciências Exatas, Naturais e da Saúde, Departamento de Farmácia e Nutrição, Alto Universitário, s/n, 29500-000 Alegre, ES, Brazil
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Javaid R, Sabir A, Sheikh N, Ferhan M. Recent Advances in Applications of Acidophilic Fungi to Produce Chemicals. Molecules 2019; 24:E786. [PMID: 30813221 PMCID: PMC6412211 DOI: 10.3390/molecules24040786] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 07/28/2018] [Accepted: 08/08/2018] [Indexed: 12/16/2022] Open
Abstract
Processing of fossil fuels is the major environmental issue today. Biomass utilization for the production of chemicals presents an alternative to simple energy generation by burning. Lignocellulosic biomass (cellulose, hemicellulose and lignin) is abundant and has been used for variety of purposes. Among them, lignin polymer having phenyl-propanoid subunits linked together either through C-C bonds or ether linkages can produce chemicals. It can be depolymerized by fungi using their enzyme machinery (laccases and peroxidases). Both acetic acid and formic acid production by certain fungi contribute significantly to lignin depolymerization. Fungal natural organic acids production is thought to have many key roles in nature depending upon the type of fungi producing them. Biological conversion of lignocellulosic biomass is beneficial over physiochemical processes. Laccases, copper containing proteins oxidize a broad spectrum of inorganic as well as organic compounds but most specifically phenolic compounds by radical catalyzed mechanism. Similarly, lignin peroxidases (LiP), heme containing proteins perform a vital part in oxidizing a wide variety of aromatic compounds with H₂O₂. Lignin depolymerization yields value-added compounds, the important ones are aromatics and phenols as well as certain polymers like polyurethane and carbon fibers. Thus, this review will provide a concept that biological modifications of lignin using acidophilic fungi can generate certain value added and environmentally friendly chemicals.
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Affiliation(s)
- Rehman Javaid
- Lignin Valorization & Nanomaterials Lab, Centre for Applied Molecular Biology (CAMB), University of the Punjab, 87-West Canal Bank Road, Thokar Niaz Baig, 53700 Lahore, Pakistan.
- Cell and Molecular Biology Lab, Department of Zoology, University of the Punjab Quaid-e Azam Campus, 54590 Lahore, Pakistan.
| | - Aqsa Sabir
- Lignin Valorization & Nanomaterials Lab, Centre for Applied Molecular Biology (CAMB), University of the Punjab, 87-West Canal Bank Road, Thokar Niaz Baig, 53700 Lahore, Pakistan.
| | - Nadeem Sheikh
- Lignin Valorization & Nanomaterials Lab, Centre for Applied Molecular Biology (CAMB), University of the Punjab, 87-West Canal Bank Road, Thokar Niaz Baig, 53700 Lahore, Pakistan.
- Cell and Molecular Biology Lab, Department of Zoology, University of the Punjab Quaid-e Azam Campus, 54590 Lahore, Pakistan.
| | - Muhammad Ferhan
- Lignin Valorization & Nanomaterials Lab, Centre for Applied Molecular Biology (CAMB), University of the Punjab, 87-West Canal Bank Road, Thokar Niaz Baig, 53700 Lahore, Pakistan.
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Min K, Yum T, Kim J, Woo HM, Kim Y, Sang BI, Yoo YJ, Kim YH, Um Y. Perspectives for biocatalytic lignin utilization: cleaving 4- O-5 and C α-C β bonds in dimeric lignin model compounds catalyzed by a promiscuous activity of tyrosinase. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:212. [PMID: 28912833 PMCID: PMC5594458 DOI: 10.1186/s13068-017-0900-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Accepted: 09/05/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND In the biorefinery utilizing lignocellulosic biomasses, lignin decomposition to value-added phenolic derivatives is a key issue, and recently biocatalytic delignification is emerging owing to its superior selectivity, low energy consumption, and unparalleled sustainability. However, besides heme-containing peroxidases and laccases, information about lignolytic biocatalysts is still limited till date. RESULTS Herein, we report a promiscuous activity of tyrosinase which is closely associated with delignification requiring high redox potentials (>1.4 V vs. normal hydrogen electrode [NHE]). The promiscuous activity of tyrosinase not only oxidizes veratryl alcohol, a commonly used nonphenolic substrate for assaying ligninolytic activity, to veratraldehyde but also cleaves the 4-O-5 and Cα-Cβ bonds in 4-phenoxyphenol and guaiacyl glycerol-β-guaiacyl ether (GGE) that are dimeric lignin model compounds. Cyclic voltammograms additionally verified that the promiscuous activity oxidizes lignin-related high redox potential substrates. CONCLUSION These results might be applicable for extending the versatility of tyrosinase toward biocatalytic delignification as well as suggesting a new perspective for sustainable lignin utilization. Furthermore, the results provide insight for exploring the previously unknown promiscuous activities of biocatalysts much more diverse than ever thought before, thereby innovatively expanding the applicable area of biocatalysis.
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Affiliation(s)
- Kyoungseon Min
- Clean Energy Research Center, Korea Institute of Science and Technology (KIST), Seoul, 02792 Republic of Korea
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919 Republic of Korea
- Present Address: Gwangju Bioenergy Research Center, Korea Institute of Energy Research (KIER), Daejeon, 34129 Republic of Korea
| | - Taewoo Yum
- Clean Energy Research Center, Korea Institute of Science and Technology (KIST), Seoul, 02792 Republic of Korea
| | - Jiye Kim
- Clean Energy Research Center, Korea Institute of Science and Technology (KIST), Seoul, 02792 Republic of Korea
| | - Han Min Woo
- Clean Energy Research Center, Korea Institute of Science and Technology (KIST), Seoul, 02792 Republic of Korea
- Present Address: Department of Food Sciencen and Biotechnology, Sungkyunkwan University, Suwon, 16419 Republic of Korea
| | - Yunje Kim
- Clean Energy Research Center, Korea Institute of Science and Technology (KIST), Seoul, 02792 Republic of Korea
| | - Byoung-In Sang
- Department of Chemical Engineering, Hanyang University, Seoul, 04763 Republic of Korea
| | - Young Je Yoo
- School of Chemical and Biological Engineering, Seoul National University, Seoul, 08826 Republic of Korea
| | - Yong Hwan Kim
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919 Republic of Korea
| | - Youngsoon Um
- Clean Energy Research Center, Korea Institute of Science and Technology (KIST), Seoul, 02792 Republic of Korea
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Aguayo-Ulloa L, Pascual-Alonso M, Campo M, Olleta J, Villarroel M, Pizarro D, Miranda-de la Lama G, María G. Effects of an enriched housing environment on sensory aspects and fatty-acid composition of the longissimus muscle of light-weight finished lambs. Meat Sci 2014; 97:490-6. [DOI: 10.1016/j.meatsci.2014.02.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Revised: 02/21/2014] [Accepted: 02/28/2014] [Indexed: 10/25/2022]
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Jokela J, Pellinen J, Salkinoja-Salonen M. Initial steps in the pathway for bacterial degradation of two tetrameric lignin model compounds. Appl Environ Microbiol 2010; 53:2642-9. [PMID: 16347484 PMCID: PMC204166 DOI: 10.1128/aem.53.11.2642-2649.1987] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We investigated the metabolic route by which a lignin tetramer-degrading mixed bacterial culture degraded two tetrameric lignin model compounds containing beta-O-4 and 5-5 biphenyl structures. The alpha-hydroxyl groups in the propane chain of both phenolic and nonphenolic tetramers were first oxidized symmetrically in two successive steps to give monoketones and diketones. These ketone metabolites were decomposed through C(alpha)(=O)-C(beta) cleavage, forming trimeric carboxyl acids which were further metabolized through another C(alpha)(=O)-C(beta) cleavage. Dehydrodiveratric acid, which resulted from the cleavage of the carbon bonds of the nonphenol tetramer, was demethylated twice. Four metabolites of the phenolic tetramer were purified and identified. All of these were stable compounds in sterile mineral medium, but were readily degraded by lignin tetramer-degrading bacteria along the same pathway as the phenol tetramer. No monoaromatic metabolites accumulated. All metabolites were identified by mass and proton magnetic resonance spectrometry. The metabolic route by which the mixed bacterial culture degraded tetrameric lignin model compounds was different from the route of the main ligninase-catalyzed C(alpha)-C(beta) cleavage by Phanerochaete chrysosporium.
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Affiliation(s)
- J Jokela
- Department of General Microbiology, University of Helsinki, SF 00280 Helsinki, Finland
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Vasta V, Priolo A. Ruminant fat volatiles as affected by diet. A review. Meat Sci 2006; 73:218-28. [PMID: 22062292 DOI: 10.1016/j.meatsci.2005.11.017] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2005] [Revised: 11/18/2005] [Accepted: 11/18/2005] [Indexed: 10/25/2022]
Abstract
Volatile compounds in meat have been widely studied for their favourable or undesirable effects on meat flavour, or for their potential use in tracing the animal feeding system. To date, the chemical mechanisms causing the appearance of volatile compounds in meat have been largely understood. Several variables are involved in the accumulation of volatiles in animal tissues and among them animal diet plays a key role. The purpose of the present review is to highlight the effects of different dietary regimes (concentrate, green grass and fat-enriched diets) on the appearance of fat volatile compounds in ruminant meat. Grain-based diets induce greater accumulations in meat of branched-chain fatty acids, some aldehydes, and lactones while meat fat from grazing animals contains high levels of phenols, terpenes, indoles and sulphur compounds. Fat-enriched diets exert their effect mainly on those volatiles which originate from polyunsaturated fatty acids. Cooking procedures have been considered for their contribution to fat volatiles in meat by reactions induced by high temperatures.
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Affiliation(s)
- V Vasta
- Dottorato di Ricerca in Produzioni Foraggere Mediterranee, University of Palermo, Viale delle Scienze 13, 90128 Palermo, Italy
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Chen L, Nanny MA, Knappe DRU, Wagner TB, Ratasuk N. Chemical characterization and sorption capacity measurements of degraded newsprint from a landfill. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2004; 38:3542-3550. [PMID: 15296303 DOI: 10.1021/es0305914] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Newsprint samples collected from 12-16 ft (top layer (TNP)), 20-24 ft (middle layer (MNP)), and 32-36 ft (bottom layer (BNP)) below the surface of the Norman Landfill (NLF) were characterized by infrared (IR) spectroscopy, cross-polarization, magic-angle spinning 13C nuclear magnetic resonance (CP-MAS 13C NMR) spectroscopy, and tetramethylammonium hydroxide (TMAH) thermochemolysis gas chromatography/mass spectrometry (GC/MS). The extent of NLF newsprint degradation was evaluated by comparing the chemical composition of NLF newsprint to that of fresh newsprint (FNP) and newsprint degraded in the laboratory under methanogenic conditions (DNP). The O-alkyl/alkyl, cellulose/lignin, and lignin/resin acid ratios showed that BNP was the most degraded, and that all three NLF newsprint samples were more degraded than DNP. 13C NMR and TMAH thermochemolysis data demonstrated selective enrichment of lignin over cellulose, and TMAH thermochemolysis further exhibited selective enrichment of resin acids over lignin. In addition, the crystallinity of cellulose in NLF newsprint samples was significantly lower relative to that of FNP and DNP as shown by 13C NMR spectra. The yield of lignin monomers from TMAH thermochemolysis suggested that hydroxyl groups were removed from the propyl side chain of lignin during the anaerobic decomposition of newsprint in the NLF. Moreover, the vanillyl acid/aldehyde ratio, which successfully describes aerobic lignin degradation, was not a good indicator of the anaerobic degradation of lignin on the basis of the TMAH data. The toluene sorption capacity increased as the degree of newsprint degradation increased or as the O-alkyl/alkyl ratio of newsprint decreased. The results of this study further verified that the sorbent O-alkyl/ alkyl ratio is useful for predicting sorption capacities of natural organic materials for hydrophobic organic contaminants.
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Affiliation(s)
- Lixia Chen
- School of Civil Engineering and Environmental Science, University of Oklahoma, Norman, Oklahoma, USA
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Kajikawa H, Kudo H, Kondo T, Jodai K, Honda Y, Kuwahara M, Watanabe T. Degradation of benzyl ether bonds of lignin by ruminal microbes. FEMS Microbiol Lett 2000; 187:15-20. [PMID: 10828393 DOI: 10.1111/j.1574-6968.2000.tb09129.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
We examined microbial activity in the rumen to cleave benzyl ether bonds of lignin model compounds that fluoresced when the bonds were cleaved. 4-Methylumbelliferone veratryl ether dimer was degraded completely within 8 h even in the presence of fungicidal antibiotics, but no significant degradation occurred with bactericidal antibiotics. Degradation of a phenolic beta-O-4 trimer incorporating 4-methylumbelliferone by a benzyl ether linkage was stimulated by ruminal microbes, although its corresponding non-phenolic model compound, 1-(4-ethoxy-3-methoxyphenyl)-1-O-(4-methylumbelliferyl)-2-(2-methoxyp henoxy)-3-propanol, was not degraded. A coniferyl dehydrogenation polymer bearing fluorescent beta-O-4 benzyl ether that contains both phenolic and non-phenolic benzyl ether bonds was partially degraded (about 20%) in 48 h. These results suggest that ruminal microbes decompose benzyl ether linkages of lignin polymers under anaerobic conditions.
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Affiliation(s)
- H Kajikawa
- National Institute of Animal Industry, Tsukuba Norindanchi, Ibaraki, Japan
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Kortekaas S, Vidal G, Yan-Ling H, Lettinga G, Field JA. Anaerobic-aerobic treatment of toxic pulping black liquor with upfront effluent recirculation. ACTA ACUST UNITED AC 1998. [DOI: 10.1016/s0922-338x(98)80041-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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Besle JM, Jouany JP, Cornu A. Transformations of structural phenylpropanoids during cell wall digestion. FEMS Microbiol Rev 1995. [DOI: 10.1111/j.1574-6976.1995.tb00154.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Field JA, Stams AJ, Kato M, Schraa G. Enhanced biodegradation of aromatic pollutants in cocultures of anaerobic and aerobic bacterial consortia. Antonie Van Leeuwenhoek 1995; 67:47-77. [PMID: 7741529 DOI: 10.1007/bf00872195] [Citation(s) in RCA: 132] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Toxic aromatic pollutants, concentrated in industrial wastes and contaminated sites, can potentially be eliminated by low cost bioremediation systems. Most commonly, the goal of these treatment systems is directed at providing optimum environmental conditions for the mineralization of the pollutants by naturally occurring microflora. Electrophilic aromatic pollutants with multiple chloro, nitro and azo groups have proven to be persistent to biodegradation by aerobic bacteria. These compounds are readily reduced by anaerobic consortia to lower chlorinated aromatics or aromatic amines but are not mineralized further. The reduction increases the susceptibility of the aromatic molecule for oxygenolytic attack. Sequencing anaerobic and and aerobic biotreatment steps provide enhanced mineralization of many electrophilic aromatic pollutants. The combined activity of anaerobic and aerobic bacteria can also be obtained in a single treatment step if the bacteria are immobilized in particulate matrices (e.g. biofilm, soil aggregate, etc.). Due to the rapid uptake of oxygen by aerobes and facultative bacteria compared to the slow diffusion of oxygen, oxygen penetration into active biofilms seldom exceeds several hundred micrometers. The anaerobic microniches established inside the biofilms can be applied to the reduction of electron withdrawing functional groups in order to prepare recalcitrant aromatic compounds for further mineralization in the aerobic outer layer of the biofilm. Aside from mineralization, polyhydroxylated and chlorinated phenols as well as nitroaromatics and aromatic amines are susceptible to polymerization in aerobic environments. Consequently an alternative approach for bioremediation systems can be directed towards incorporating these aromatic pollutants into detoxified humic-like substances. The activation of aromatic pollutants for polymerization can potentially be encouraged by an anaerobic pretreatment step prior to oxidation. Anaerobic bacteria can modify aromatic pollutants by demethylating methoxy groups and reducing nitro groups. The resulting phenols and aromatic amines are readily polymerized in a subsequent aerobic step.
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Affiliation(s)
- J A Field
- Department of Environmental Technology, Wageningen Agricultural University, The Netherlands
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McSweeney CS, Dulieu A, Katayama Y, Lowry JB. Solubilization of lignin by the ruminal anaerobic fungus Neocallimastix patriciarum. Appl Environ Microbiol 1994; 60:2985-9. [PMID: 8085834 PMCID: PMC201753 DOI: 10.1128/aem.60.8.2985-2989.1994] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The ability of the ruminal anaerobic phycomycete Neocallimastix patriciarum to digest model lignin compounds and lignified structures in plant material was studied in batch culture. The fungus did not degrade or transform model lignin compounds that were representative of the predominant intermonomer linkages in lignin, nor did it solubilize acid detergent lignin that had been isolated from spear grass. In a stem fraction of sorghum, 33.6% of lignin was apparently solubilized by the fungus. Solubilization of ester- and either-linked phenolics accounted for 9.2% of the lignin released. The amounts of free phenolic acids detected in culture fluid were equivalent to the apparent loss of ester-linked phenolics from the sorghum substrate. However, the fungus was unable to cleave the ether bond in hydroxycinnamic acid bridges that cross-link lignin and polysaccharide. It is suggested that the majority of the solubilized lignin fraction was a lignin carbohydrate complex containing ether-linked hydroxycinnamic acids. The lignin carbohydrate complex was probably solubilized through dissolution of xylan in the lignin-xylan matrix rather than by lignin depolymerization.
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Affiliation(s)
- C S McSweeney
- Long Pocket Laboratories, CSIRO Division of Tropical Animal Production, Indooroopilly, Queensland, Australia
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Isolation and characterization of dioxane-soluble lignins from faeces of sheep fed on orchardgrass hay and silage. Anim Feed Sci Technol 1993. [DOI: 10.1016/0377-8401(93)90014-b] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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15
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HA JKIM, LINDSAY R. Volatile Alkylphenols and Thiophenol in Species-related Characterizing Flavors of Red Meats. J Food Sci 1991. [DOI: 10.1111/j.1365-2621.1991.tb04733.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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17
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Silanikove N, Brosh A. Lignocellulose degradation and subsequent metabolism of lignin fermentation products by the desert black Bedouin goat fed on wheat straw as a single-component diet. Br J Nutr 1989; 62:509-20. [PMID: 2819030 DOI: 10.1079/bjn19890049] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Bedouin goats were fed on wheat straw as a single-component diet under two watering regimens, drinking once daily or once every 4 d, in order to clarify whether lignin-degradation products were absorbed, metabolized and excreted in urine. Acid-soluble lignin accounted for 220 g/kg total lignin, its digestibility was the highest (0.87) and was unaffected by water deprivation. Acid-insoluble lignin accounted for 780 g/kg total lignin and its digestibility increased during water deprivation from 0.21 to 0.41. Alkali-soluble lignin accounted for 320 g/kg total lignin and its digestibility increased during water deprivation from 0.44 to 0.53. Digestibility of structural carbohydrate was considerably higher than that observed in other domesticated ruminants fed on wheat straw. It responded positively to water deprivation, increasing from 0.63 to 0.73 with cellulose and from 0.61 to 0.68 with hemicellulose. The amount of urinary aromatic acids, mainly in the form of hippuric acid, considerably exceeded the potential contribution of any non-lignin component which might affect the excretion of aromatic acids. A considerable percentage (71-76) of the apparently digested lignin was not accounted for as soluble phenolic compounds in faeces or as aromatic acids in urine, and hence was apparently completely metabolized. Lignin is a key substrate which is extensively digested in goats fed on low-quality forage, with subsequent absorption of endproducts. This enhanced the availability of structural carbohydrates for fermentation and was associated with excretion of high-energy metabolites in the form of benzoic and hippuric acids.
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Affiliation(s)
- N Silanikove
- Migal-Galilee Technical Center, Kiryat Shmona, Israel
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den Camp HJMO, Verhagen FJM, Kivaisi AK, de Windt FE. Effects of lignin on the anaerobic degradation of (ligno) cellulosic wastes by rumen microorganisms. Appl Microbiol Biotechnol 1988. [DOI: 10.1007/bf00265827] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Chen W, Ohmiya K, Shimizu S, Kawakami H. Isolation and characterization of an anaerobic dehydrodivanillin-degrading bacterium. Appl Environ Microbiol 1988; 54:1254-7. [PMID: 3389817 PMCID: PMC202635 DOI: 10.1128/aem.54.5.1254-1257.1988] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
A novel, strictly anaerobic, gram-negative, non-spore-forming, fusiform, rod-shaped bacterium having high dehydrodivanillin (DDV)-degrading activity was isolated from cow ruminal fluid. This strain degraded a range of six main lignin-related compounds such as DDV, ferulic acid, dehydrodiisoeugenol, guaiacoxyacetic acid, vanillin, and veratrylglycerol-beta-guaiacyl ether to the extent of 14 to 83% within 2 days under strictly anaerobic conditions. As DDV degradation intermediates, three aromatic compounds (dehydrodivanillic acid, vanillic acid, and 5-carboxyvanillic acid) and two alicyclic compounds (cyclohexanecarboxylic acid and cyclohexanol) were detected by thin-layer, high-performance liquid, and gas chromatography and mass spectrometry. The addition of 1% glucose and peptone in a synthetic medium stimulated growth of the strain but slowed down DDV degradation. The presence of 0.1% yeast extract increased both cell growth and DDV degradation. The growth yield in defined medium was 151.5 g (dry weight) of cells per mol of DDV utilized. Characterization of the strain indicated that it was distinct from known Fusobacterium and Clostridium species. The bacterium was easily induced to form protoplasts after treatment with either penicillin or lysozyme. The frequencies of protoplast formation and regeneration in the strain were 94 and 18%, respectively.
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Affiliation(s)
- W Chen
- Department of Food Science and Technology, School of Agriculture, Nagoya University, Japan
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Vicuña R, González B, Mozuch MD, Kirk TK. Metabolism of Lignin Model Compounds of the Arylglycerol-β-Aryl Ether Type by
Pseudomonas acidovorans
D
3. Appl Environ Microbiol 1987; 53:2605-9. [PMID: 16347479 PMCID: PMC204160 DOI: 10.1128/aem.53.11.2605-2609.1987] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A natural bacterial isolate that we have classified as
Pseudomonas acidovorans
grows on the lignin model compounds 1-(3,4-dimethoxyphenyl)-2-(2-methoxyphenoxy)propane-1,3-diol (compound 1) and 1-(4-hydroxy-3-methoxyphenyl)-2-(2-methoxyphenoxy)propane-1,3-diol (compound 1′), as well as on the corresponding 1-oxo compounds (2 and 2′) as sole sources of carbon and energy. Metabolic intermediates present in cultures growing on compound 1 included compound 2, 2-methoxyphenol (guaiacol [compound 3]), β-hydroxypro-pioveratrone (compound 4), acetoveratrone (compound 5), and veratric acid (compound 6). Also identified were compounds 1′, 2′, β-hydroxypropiovanillone (compound 4′), and acetovanillone (compound 5′), indicating that 4-O demethylation also occurs. The phenolic intermediates were the same as those found in cultures growing on compound 1′. Compounds 2 and 2′ were in part also reduced to compounds 1 and 1′, respectively. Compound 3 was shown to be derived from the 2-methoxyphenoxy moiety. A suggested degradation scheme is as follows: compound 1→2→(3 + 4)→5→6 (and similarly for 1′). In this scheme, the key reaction is cleavage of the ether linkage between C-2 (C
β
) of the phenylpropane moiety and the 2-methoxyphenoxy moiety in compounds 2 and 2′ (i.e., β-aryl ether cleavage). On the basis of compounds identified, viz., 3 and 4 (4′), cleavage appears formally to be reductive. Because this is unlikely, the initial cleavage products probably were not detected. The implications of these results for the enzyme(s) responsible are discussed.
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Affiliation(s)
- R Vicuña
- Laboratorio de Bioquimica, Pontificia Universidad Catolica de Chile, Santiago, Chile, and Forest Products Laboratory, Forest Service, U.S. Department of Agriculture, Madison, Wisconsin 53705-2398
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Neilson AH, Allard AS, Lindgren C, Remberger M. Transformations of chloroguaiacols, chloroveratroles, and chlorocatechols by stable consortia of anaerobic bacteria. Appl Environ Microbiol 1987; 53:2511-9. [PMID: 3426218 PMCID: PMC204138 DOI: 10.1128/aem.53.10.2511-2519.1987] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Metabolically stable consortia of anaerobic bacteria obtained by enrichment of sediment samples with 3,4,5-trimethoxybenzoate (TMBA), 3,4,5-trihydroxybenzoate (gallate [GA]), or 5-chlorovanillin (CV) were used to study the anaerobic transformation of a series of chloroveratroles, chloroguaiacols, and chlorocatechols used as cosubstrates. Experiments were carried out with growing cultures, and the following pathways were demonstrated for metabolism of the growth substrates: (i) TMBA produced GA, which was further degraded without the formation of aromatic intermediates; (ii) GA formed pyrogallol, which was stable to further transformation; and (iii) CV was degraded by a series of steps involving de-O-methylation, oxidation of the aldehyde group, and decarboxylation to 3-chlorocatechol before ring cleavage. Mono-de-O-methylation of the cosubstrates occurred rapidly in the order 4,5,6-trichloroguaiacol greater than 3,4,5-trichloroguaiacol approximately 3,4,5-trichloroveratrole approximately tetrachloroveratrole greater than tetrachloroguaiacol and was concomitant with degradation of the growth substrates. For the polymethoxy compounds--chloroveratroles, 1,2,3-trichloro-4,5,6-trimethoxybenzene, and 4,5,6-trichlorosyringol--de-O-methylation took place sequentially. The resulting chlorocatechols were stable to further transformation until the cultures had exhausted the growth substrates; selective dechlorination then occurred with the formation of 3,5-dichlorocatechol from 3,4,5-trichlorocatechol and of 3,4,6-trichlorocatechol from tetrachlorocatechol. 2,4,5-, 2,4,6-, and 3,4,5-trichoroanisole and 2,3,4,5-tetrachloroanisole were de-O-methylated, but the resulting chlorophenols were resistant to dechlorination. These results extend those of a previous study with spiked sediment samples and their endogenous microflora and illustrate some of the transformations of chloroguaiacols and chlorocatechols which may be expected to occur in anaerobic sediments.
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Affiliation(s)
- A H Neilson
- Swedish Environmental Research Institute, Stockholm
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