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Wang G, Wu W, Keller NP, Guo X, Li E, Ma J, Xing F. Metarhizium spp. encode an ochratoxin cluster and a high efficiency ochratoxin-degrading amidohydrolase revealed by genomic analysis. J Adv Res 2024:S2090-1232(24)00308-4. [PMID: 39089618 DOI: 10.1016/j.jare.2024.07.023] [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: 11/20/2023] [Revised: 07/02/2024] [Accepted: 07/25/2024] [Indexed: 08/04/2024] Open
Abstract
INTRODUCTION Ochratoxins (OTs) are worldwide regulated mycotoxins contaminating a variety of food-environment and agro-environment. Several Aspergillus and Pencillium species synthesize OTs from a six-gene biosynthetic gene cluster (BGC) to produce the highly toxic final product OTA. Although many studies on OTA-degrading enzymes were performed, high efficiency enzymes with strong stability are extremely needed, and the OTA degrading mechanism is poorly understood. OBJECTIVES The study aimed to explore the OT-degradation enzyme and investigate its degradation mechanisms in Metarhizium, which contain an OT biosynthetic gene cluster. METHODS Phylogenomic relationship combined with RNA expression analysis were used to explore the distribution of OT BGC in fungi. Bioactivity-guided isolation and protein mass spectrometry were conducted to trace the degrading enzymes in Metarhizium spp., and the enzymes were heterologously expressed in E. coli and verified by in vitro assays. Structure prediction and point mutation were performed to reveal the catalytic mechanism of MbAmh1. RESULTS Beyond Aspergillus and Pencillium species, three species of the distant phylogenetic taxon Metarhizium contain an expressed OT-like BGC but lack an otaD gene. Unexpectedly, no OT BGC products were found in some Metarhizium species. Instead, Metarhizium metabolized both OTA and OTB to their non-toxic degradation products. This activity of M. brunneum was attributed to an intracellular hydrolase MbAmh1, which was tracked by bioactivity-guided proteomic analysis combined with in vitro reaction. Recombinant MbAmh1 (5 μg/mL) completely degraded 1 μg/mL OTA within 3 min, demonstrating a strong degrading ability towards OTA. Additionally, MbAmh1 showed considerable temperature adaptability ranging from 30 to 70 °C and acidic pH stability ranging from 4.0 to 7.0. Identification of active sites supported the crucial role of metal iron for this enzymatic reaction. CONCLUSION These findings reveal different patterns of OT synthesis in fungi and provide a potential OTA degrading enzyme for industrial applications.
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Affiliation(s)
- Gang Wang
- Key Laboratory of Agro-Products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, PR China.
| | - Wenqing Wu
- Horticulture and Landscape College, Tianjin Agricultural University, Tianjin 300392, PR China.
| | - Nancy P Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI 53706, USA.
| | - Xu Guo
- Horticulture and Landscape College, Tianjin Agricultural University, Tianjin 300392, PR China.
| | - Erfeng Li
- Horticulture and Landscape College, Tianjin Agricultural University, Tianjin 300392, PR China.
| | - Junning Ma
- Key Laboratory of Agro-Products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, PR China.
| | - Fuguo Xing
- Key Laboratory of Agro-Products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, PR China.
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Huang J, Chen D, Jiang J. Preferential catabolism of the (S)-enantiomer of the herbicide napropamide mediated by the enantioselective amidohydrolase SnaH and the dioxygenase Snpd in Sphingobium sp. strain B2. Environ Microbiol 2019; 22:286-296. [PMID: 31667998 DOI: 10.1111/1462-2920.14847] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 10/25/2019] [Accepted: 10/28/2019] [Indexed: 12/25/2022]
Abstract
The (R)- and (S)-enantiomers of the chiral herbicide napropamide (NAP) show different biological activities and ecotoxicities. These two enantiomers behave differently in the environment due to enantioselective catabolism by microorganisms. However, the molecular mechanisms underlying this enantioselective catabolism remain largely unknown. In this study, the genes (snaH and snpd) involved in the catabolism of NAP were cloned from Sphingobium sp. B2, which was capable of catabolizing both NAP enantiomers. Compared with (R)-NAP, (S)-NAP was much more rapidly transformed by the amidase SnaH, which initially cleaved the amide bonds of (S)/(R)-NAP to form (S)/(R)-2-(1-naphthalenyloxy)-propanoic acid [(S)/(R)-NP] and diethylamine. The α-ketoglutarate-dependent dioxygenase Snpd, showing strict stereoselectivity for (S)-NP, further transformed (S)-NP to 1-naphthol and pyruvate. Molecular docking and site-directed mutagenesis analyses revealed that when the (S)-enantiomers of NAP and NP occupied the active sites, the distance between the ligand molecule and the coordination atom was shorter than that when the (R)-enantiomers occupied the active sites, which facilitated formation of the transition state complex. This study enhances our understanding of the preferential catabolism of the (S)-enantiomer of NAP on the molecular level.
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Affiliation(s)
- Junwei Huang
- Department of Microbiology, Key Lab of Microbiology for Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 210095, Nanjing, China
| | - Dian Chen
- Department of Microbiology, Key Lab of Microbiology for Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 210095, Nanjing, China.,State Key Laboratory of Microbial Metabolism, School of Life Science and Biotechnology, Shanghai Jiao Tong University, 200240, Shanghai, China
| | - Jiandong Jiang
- Department of Microbiology, Key Lab of Microbiology for Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 210095, Nanjing, China
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Lopes AR, Sousa VM, Estevinho BN, Leite JP, Moreira NFF, Gales L, Rocha F, Nunes OC. Production of microparticles of molinate degrading biocatalysts using the spray drying technique. CHEMOSPHERE 2016; 161:61-68. [PMID: 27421102 DOI: 10.1016/j.chemosphere.2016.07.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 06/16/2016] [Accepted: 07/02/2016] [Indexed: 06/06/2023]
Abstract
Previous studies demonstrated the capability of mixed culture DC1 to mineralize the thiocarbamate herbicide molinate through the activity of molinate hydrolase (MolA). Because liquid suspensions are not compatible with long-term storage and are not easy to handle when bioremediation strategies are envisaged, in this study spray drying was evaluated as a cost-effective method to store and transport these molinate biocatalysts. Microparticles of mixed culture DC1 (DC1) and of cell free crude extracts containing MolA (MA) were obtained without any carrier polymer, and with calcium alginate (CA) or modified chitosan (MCt) as immobilizing agents. All the DC1 microparticles showed high molinate degrading activity upon storage for 6 months, or after 9 additions of ∼0.4 mM molinate over 1 month. The DC1-MCt microparticles were those with the highest survival rate and lowest heterogeneity. For MA microparticles, only MA-MCt degraded molinate. However, its Vmax was only 1.4% of that of the fresh cell free extract (non spray dried). The feasibility of using the DC1-MCt and MA-MCt microparticles in bioaugmentation processes was assessed in river water microcosms, using mass (g):volume (L) ratios of 1:13 and 1:0.25, respectively. Both type of microparticles removed ∼65-75% of the initial 1.5 mg L(-1) molinate, after 7 days of incubation. However, only DC1-MCt microparticles were able to degrade this environmental concentration of molinate without disturbing the native bacterial community. These results suggest that spray drying can be successfully used to produce DC1-MCt microparticles to remediate molinate polluted sites through a bioaugmentation strategy.
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Affiliation(s)
- Ana R Lopes
- LEPABE, Laboratório de Engenharia de Processos, Ambiente, Biotecnologia e Energia, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Vera M Sousa
- LEPABE, Laboratório de Engenharia de Processos, Ambiente, Biotecnologia e Energia, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Berta N Estevinho
- LEPABE, Laboratório de Engenharia de Processos, Ambiente, Biotecnologia e Energia, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - José P Leite
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal; IBMC, Instituto de Biologia Molecular e Celular da Universidade do Porto, Rua do Campo Alegre, 823, 4150-180 Porto, Portugal
| | - Nuno F F Moreira
- LEPABE, Laboratório de Engenharia de Processos, Ambiente, Biotecnologia e Energia, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Luís Gales
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal; IBMC, Instituto de Biologia Molecular e Celular da Universidade do Porto, Rua do Campo Alegre, 823, 4150-180 Porto, Portugal; ICBAS - Instituto de Ciências Biomédicas Abel Salazar, Rua de Jorge Viterbo Ferreira n.º 228, 4050-313 Porto, Portugal
| | - Fernando Rocha
- LEPABE, Laboratório de Engenharia de Processos, Ambiente, Biotecnologia e Energia, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Olga C Nunes
- LEPABE, Laboratório de Engenharia de Processos, Ambiente, Biotecnologia e Energia, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal.
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