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Kim HS, Abassi S, Bui QTN, Ki JS. Nitrogen (N) balancing metabolism in the toxic dinoflagellate Alexandrium pacificum against N shift revealed by physiology and N-related genes regulation. CHEMOSPHERE 2025; 379:144437. [PMID: 40279932 DOI: 10.1016/j.chemosphere.2025.144437] [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: 01/06/2025] [Revised: 04/18/2025] [Accepted: 04/21/2025] [Indexed: 04/29/2025]
Abstract
The dinoflagellate Alexandrium pacificum is responsible for harmful algal blooms and paralytic shellfish poisoning in marine environments. Its physiology is greatly affected by nitrogen (N) sources; however, the molecular mechanisms involved in N acquisition and balancing are not clearly understood. Here, we determined the full-length gene sequences of nitrate (NO3-) transporter (ApNRT), NO3- reductase (ApNR), and ammonium (NH4+) transporter (ApAMT) from the dinoflagellate A. pacificum. In addition, we examined physiological and transcriptional responses of these three genes under diverse concentrations of NO3- (0.00-8.82 mM) and NH4+ (0.00-1.76 mM). The open reading frames of ApNRT, ApNR, and ApAMT were determined as 1767 bp, 3312 bp, and 1363 bp, without introns in their genomic coding regions. Their encoded proteins were phylogenetically close to those of other photosynthetic eukaryotes. NO3- supplementation promoted cell growth, while NH4+ inhibited it. Expression of ApNRT and ApNR were correlated in both low and high N conditions. Sufficient uptake of one of the N forms (NO3- and NH4+, respectively) suppressed the regulation of the other dissolved inorganic nitrogen (DIN) transporter (ApAMT and ApNRT, respectively). These results showed that A. pacificum may have a selective mechanism for N uptake depending on the available N sources, suggesting a proliferation strategy of dinoflagellate in eutrophic environments.
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Affiliation(s)
- Han-Sol Kim
- Department of Life Science, Sangmyung University, Seoul, 03016, South Korea; Institute of Natural Science, Sangmyung University, Seoul, 03016, South Korea
| | - Sofia Abassi
- Department of Life Science, Sangmyung University, Seoul, 03016, South Korea
| | - Quynh Thi Nhu Bui
- Department of Life Science, Sangmyung University, Seoul, 03016, South Korea
| | - Jang-Seu Ki
- Department of Life Science, Sangmyung University, Seoul, 03016, South Korea; Institute of Natural Science, Sangmyung University, Seoul, 03016, South Korea.
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Lv J, Sun D, Yan D, Ti X, Liu P, Li J. Quantitative Trait Loci Mapping and Marker Identification for Low Salinity Tolerance Trait in the Swimming Crab ( Portunus trituberculatus). Front Genet 2019; 10:1193. [PMID: 31850064 PMCID: PMC6900548 DOI: 10.3389/fgene.2019.01193] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 10/28/2019] [Indexed: 01/17/2023] Open
Abstract
Low salinity is one of the most important abiotic factors that directly affect the abundance of the swimming crab, Portunus trituberculatus. Quantitative trait loci (QTL) mapping could be helpful in identifying the markers and genes involved in low salinity tolerance. In this study, two QTLs of low salt tolerance were mapped on linkage group 17 (LG17, 2.6-5.2 cM) based on a high-density linkage map. Ninety-five markers related to low salinity tolerance were identified via association analysis, and seventy-nine low salt-related candidate genes (including ammonium transport, aldehyde dehydrogenase, and glucosyltransferase) were screened from draft genome of the species via these markers. This represents the first report of QTL mapping for low salinity tolerance in the swimming crab, which may be useful to elucidate salinity adaptation mechanisms.
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Affiliation(s)
- Jianjian Lv
- Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China.,Function Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Dongfang Sun
- Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China
| | - Deping Yan
- Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China
| | - Xingbin Ti
- Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China
| | - Ping Liu
- Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China.,Function Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Jian Li
- Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China.,Function Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
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Lauritano C, De Luca D, Amoroso M, Benfatto S, Maestri S, Racioppi C, Esposito F, Ianora A. New molecular insights on the response of the green alga Tetraselmis suecica to nitrogen starvation. Sci Rep 2019; 9:3336. [PMID: 30833632 PMCID: PMC6399242 DOI: 10.1038/s41598-019-39860-5] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 02/01/2019] [Indexed: 12/20/2022] Open
Abstract
Microalgae are currently considered one of the most promising resources for biofuel production, aquaculture feedstock and new pharmaceuticals. Among them, green algae of the genus Tetraselmis are extensively studied for their lipid accumulation in nutrient-starvation conditions. In this paper, we present the full-transcriptome of Tetraselmis suecica and differential expression analysis between nitrogen-starved and -repleted conditions (at stationary phase) focusing not only on lipid metabolism but giving new insights on nutrient starvation responses. Transcripts involved in signal transduction pathways, stress and antioxidant responses and solute transport were strongly up-regulated when T. suecica was cultured under nitrogen starvation. On the contrary, transcripts involved in amino acid synthesis, degradation of sugars, secondary metabolite synthesis, as well as photosynthetic activity were down-regulated under the same conditions. Among differentially expressed transcripts, a polyketide synthase and three lipoxygenases (involved in the synthesis of secondary metabolites with antipredator, anticancer and anti-infective activities) were identified, suggesting the potential synthesis of bioactive compounds by this microalga. In addition, the transcript for a putative nitrilase, enzyme used in nitrile bioremediation, is here reported for the first time for T. suecica. These findings give new insights on T. suecica responses to nutrient starvation and on possible biotechnological applications for green algae.
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Affiliation(s)
- Chiara Lauritano
- Marine Biotechnology Department, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Napoli, Italy.
| | - Daniele De Luca
- Integrative Marine Ecology Department, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Napoli, Italy
| | - Mariano Amoroso
- Marine Biotechnology Department, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Napoli, Italy
| | - Salvatore Benfatto
- Università degli Studi di Verona, Ca' Vignal 1, Strada Le Grazie 15, 37134, Verona, Italy
| | - Simone Maestri
- Università degli Studi di Verona, Ca' Vignal 1, Strada Le Grazie 15, 37134, Verona, Italy
| | - Claudia Racioppi
- Marine Biotechnology Department, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Napoli, Italy.,Center for Developmental Genetics, Department of Biology, College of Arts and Science, New York University, New York, USA
| | - Francesco Esposito
- Marine Biotechnology Department, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Napoli, Italy
| | - Adrianna Ianora
- Marine Biotechnology Department, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Napoli, Italy.
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Zhu Y, Hao Y, Liu H, Sun G, Chen R, Song S. Identification and characterization of two ammonium transporter genes in flowering Chinese cabbage ( Brassica campestris). PLANT BIOTECHNOLOGY (TOKYO, JAPAN) 2018; 35:59-70. [PMID: 31275038 PMCID: PMC6543737 DOI: 10.5511/plantbiotechnology.18.0202a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 02/02/2018] [Indexed: 06/09/2023]
Abstract
Ammonium transporters (AMTs), which include AMT1 and AMT2 subfamilies, have been identified and partially characterized in many plants. In this study, two AMT2-type genes from Brassica campestris, namely BcAMT2 and BcAMT2like, were identified and characterized. BcAMT2 and BcAMT2like are 2666 bp and 2952 bp, encode proteins of 490 and 489 amino acids, respectively, and contain five exons and four introns. Transient expression of these proteins labelled with green fluorescence protein in onion epidermal cells indicated that both are located on the plasma membrane. When expressing BcAMT2 or BcAMT2like, the mutant yeast strain 31019b could grow on medium containing 2 mM ammonium as the only nitrogen source when expressing BcAMT2 or BcAMT2like, indicating that both are functional AMT genes. Quantitative PCR results showed that BcAMT2 and BcAMT2like were expressed in all tissues, but they displayed different expression patterns in the reproductive stages. BcAMT2s transcript levels in leaves were positively correlated with ammonium concentration and external pH. Moreover, the expression BcAMT2s responded to diurnal change. Furthermore, the uncharged form of ammonium, i.e., ammonia, might also be transported by BcAMT2s. These results provide new insights into the molecular mechanisms underlying ammonium absorption and transportation by the AMT2 subfamily in B. campestris.
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Affiliation(s)
- Yunna Zhu
- College of Horticulture, South China Agricultural University, 510642, Guangzhou, People’s Republic of China
| | - Yanwei Hao
- College of Horticulture, South China Agricultural University, 510642, Guangzhou, People’s Republic of China
| | - Houcheng Liu
- College of Horticulture, South China Agricultural University, 510642, Guangzhou, People’s Republic of China
| | - Guangwen Sun
- College of Horticulture, South China Agricultural University, 510642, Guangzhou, People’s Republic of China
| | - Riyuan Chen
- College of Horticulture, South China Agricultural University, 510642, Guangzhou, People’s Republic of China
| | - Shiwei Song
- College of Horticulture, South China Agricultural University, 510642, Guangzhou, People’s Republic of China
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Kakinuma M, Nakamoto C, Kishi K, Coury DA, Amano H. Isolation and functional characterization of an ammonium transporter gene, PyAMT1, related to nitrogen assimilation in the marine macroalga Pyropia yezoensis (Rhodophyta). MARINE ENVIRONMENTAL RESEARCH 2017; 128:76-87. [PMID: 27581686 DOI: 10.1016/j.marenvres.2016.08.007] [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: 12/11/2015] [Revised: 05/25/2016] [Accepted: 08/22/2016] [Indexed: 06/06/2023]
Abstract
Ammonium and nitrate are the primary nitrogen sources in natural environments, and are essential for growth and development in photosynthetic eukaryotes. In this study, we report on the isolation and characterization of an ammonium transporter gene (PyAMT1) which performs a key function in nitrogen (N) metabolism of Pyropia yezoensis thalli. The predicted length of PyAMT1 was 483 amino acids (AAs). The AA sequence included 11 putative transmembrane domains and showed approximately 33-44% identity to algal and plant AMT1 AA sequences. Functional complementation in an AMT-defective yeast mutant indicated that PyAMT1 mediated ammonium transport across the plasma membrane. Expression analysis showed that the PyAMT1 mRNA level was strongly induced by N-deficiency, and was more highly suppressed by resupply of inorganic-N than organic-N. These results suggest that PyAMT1 plays important roles in the ammonium transport system, and is highly regulated in response to external/internal N-status.
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Affiliation(s)
- Makoto Kakinuma
- Graduate School of Bioresources, Mie University, 1577 Kurima-machiya, Tsu, Mie 514-8507, Japan.
| | - Chika Nakamoto
- Graduate School of Bioresources, Mie University, 1577 Kurima-machiya, Tsu, Mie 514-8507, Japan
| | - Kazuki Kishi
- Graduate School of Bioresources, Mie University, 1577 Kurima-machiya, Tsu, Mie 514-8507, Japan
| | - Daniel A Coury
- Graduate School of Bioresources, Mie University, 1577 Kurima-machiya, Tsu, Mie 514-8507, Japan
| | - Hideomi Amano
- Graduate School of Bioresources, Mie University, 1577 Kurima-machiya, Tsu, Mie 514-8507, Japan
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Zhu C, Fan Q, Wang W, Shen C, Meng X, Tang Y, Mei B, Xu Z, Song R. Characterization of a glutamine synthetase gene DvGS2 from Dunaliella viridis and biochemical identification of DvGS2-transgenic Arabidopsis thaliana. Gene 2014; 536:407-15. [PMID: 24334123 DOI: 10.1016/j.gene.2013.11.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 10/16/2013] [Accepted: 11/05/2013] [Indexed: 01/23/2023]
Abstract
The salt-tolerant green alga Dunaliella has remarkable capability to survive in some extreme environments such as nitrogen starvation, which makes Dunaliella be a proper model for mining novel genes on nitrogen uptake or assimilation. In this study, a glutamine synthetase (GS) gene DvGS2 with amino acid identity of 72% to other homologous GS proteins, was isolated and characterized from Dunaliella viridis. Phylogenetic comparison with other GSs revealed that DvGS2 occupied an independent phylogenetic position. Expressional analysis in D. viridis cells under nitrogen starvation confirmed that DvGS2 increased its mRNA level in 12h. Subcellular localization study and functional analysis in a GS-deficient Escherichia coli mutant proved that DvGS2 was a chloroplastic and functional GS enzyme. In order to investigate the potential application of DvGS2 in higher plants, the transgenic studies of DvGS2 in Arabidopsis thaliana were carried out. Results showed that the transgenic lines expressed the DvGS2 gene and demonstrated obviously enhanced root length (29%), fresh weight (40%-48% at two concentrations of nitrate supplies), stem length (21%), leaf size (39%) and silique number (44%) in contrast with the wild-type Arabidopsis. Furthermore, the transgenic lines had higher total nitrogen content (35%-43%), total GS activity (39%-45%) and soluble protein concentration (23%-24%) than the wild type. These results indicated that the overexpression of DvGS2 in A. thaliana resulted in higher biomass and the improvement of the host's nitrogen use efficiency.
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Affiliation(s)
- Chenguang Zhu
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, 99 Shangda Road, 200444 Shanghai, China
| | - Qianlan Fan
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, 99 Shangda Road, 200444 Shanghai, China
| | - Wei Wang
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, 99 Shangda Road, 200444 Shanghai, China
| | - Chunlei Shen
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, 99 Shangda Road, 200444 Shanghai, China
| | - Xiangzong Meng
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, 99 Shangda Road, 200444 Shanghai, China
| | - Yuanping Tang
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, 99 Shangda Road, 200444 Shanghai, China
| | - Bing Mei
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, 99 Shangda Road, 200444 Shanghai, China
| | - Zhengkai Xu
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, 99 Shangda Road, 200444 Shanghai, China
| | - Rentao Song
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, 99 Shangda Road, 200444 Shanghai, China.
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Zhu C, Fan Q, Wang W, Shen C, Wang P, Meng X, Tang Y, Mei B, Xu Z, Song R. Characterization of a glutamine synthetase gene DvGS1 from Dunaliella viridis and investigation of the impact on expression of DvGS1 in transgenic Arabidopsis thaliana. Mol Biol Rep 2013; 41:477-87. [PMID: 24307252 DOI: 10.1007/s11033-013-2882-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Accepted: 11/21/2013] [Indexed: 11/26/2022]
Abstract
A novel glutamine synthetase (GS) gene DvGS1 showing highest amino acid sequence identity of 78 % with the other homologous GS proteins from green algae, was isolated and characterized from Dunaliella viridis. Phylogenetic analysis revealed that DvGS1 occupied an independent phylogenetic position which was different with the GSs from higher plants, animals and microbes. Functional complement in E. coli mutant confirmed that the DvGS1 encoded functional GS enzyme. Real-time PCR analysis of DvGS1 in D. viridis cells under nitrogen starvation revealed that the mRNA level of DvGS1 was positively up-regulated in 12 h. The DvGS1 levels at the points of 12 and 24 h were separately twofold and fourfold of the level before nitrogen starvation. In order to investigate the potential application of DvGS1 in higher plants, the transgenic study of DvGS1 in Arabidopsis thaliana was carried out. Phenotype identification demonstrated that all three transgenic lines of T3 generation showed obviously enhanced root length (26 %), fresh weight (22-46 % at two concentrations of nitrate supplies), stem length (26 %), leaf size (29 %) and silique number (30 %) compared with the wild-type Arabidopsis. Biochemical analysis confirmed that all three transgenic lines had higher total nitrogen content, soluble protein concentration, total amino acid content and the leaf GS activity than the wild type plants. The free NH4 (+) and NO3 (-) concentration in fresh leaves of three transgenic lines were reduced by 17-26 % and 14-15 % separately (at two concentrations of nitrate supplies) compared with those of the wild types. All the results indicated that over-expression of DvGS1 in Arabidopsis significantly results in the improvement of growth phenotype and the host's nitrogen use efficiency.
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Affiliation(s)
- Chenguang Zhu
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai, 200444, China
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Scherzer S, Krol E, Kreuzer I, Kruse J, Karl F, von Rüden M, Escalante-Perez M, Müller T, Rennenberg H, Al-Rasheid KAS, Neher E, Hedrich R. The Dionaea muscipula ammonium channel DmAMT1 provides NH₄⁺ uptake associated with Venus flytrap's prey digestion. Curr Biol 2013; 23:1649-57. [PMID: 23954430 DOI: 10.1016/j.cub.2013.07.028] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Revised: 05/07/2013] [Accepted: 07/03/2013] [Indexed: 01/07/2023]
Abstract
BACKGROUND Ammonium transporter (AMT/MEP/Rh) superfamily members mediate ammonium uptake and retrieval. This pivotal transport system is conserved among all living organisms. For plants, nitrogen represents a macronutrient available in the soil as ammonium, nitrate, and organic nitrogen compounds. Plants living on extremely nutrient-poor soils have developed a number of adaptation mechanisms, including a carnivorous lifestyle. This study addresses the molecular nature, function, and regulation of prey-derived ammonium uptake in the Venus flytrap, Dionaea muscipula, one of the fastest active carnivores. RESULTS The Dionaea muscipula ammonium transporter DmAMT1 was localized in gland complexes where its expression was upregulated upon secretion. These clusters of cells decorating the inner trap surface are engaged in (1) secretion of an acidic digestive enzyme cocktail and (2) uptake of prey-derived nutrients. Voltage clamp of Xenopus oocytes expressing DmAMT1 and membrane potential recordings with DmAMT1-expressing Dionaea glands were used to monitor and compare electrophysiological properties of DmAMT1 in vitro and in planta. DmAMT1 exhibited the hallmark biophysical properties of a NH4(+)-selective channel. At depolarized membrane potentials (Vm = 0), the Km (3.2 ± 0.3 mM) indicated a low affinity of DmAMT1 for ammonium that increased systematically with negative going voltages. Upon hyperpolarization to, e.g., -200 mV, a Km of 0.14 ± 0.015 mM documents the voltage-dependent shift of DmAMT1 into a NH4(+) transport system of high affinity. CONCLUSIONS We suggest that regulation of glandular DmAMT1 and membrane potential readjustments of the endocrine cells provide for effective adaptation to varying, prey-derived ammonium sources.
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Affiliation(s)
- Sönke Scherzer
- Institute for Molecular Plant Physiology and Biophysics, Julius-von-Sachs Platz 2, 97082 Würzburg, Germany; Department for Membrane Biophysics, Max Planck Institute for Biophysical Chemistry, 37077 Goettingen, Germany
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Characterization of an ammonium transporter in the oleaginous alga Chlorella protothecoides. Appl Microbiol Biotechnol 2012; 97:919-28. [DOI: 10.1007/s00253-012-4534-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Revised: 10/18/2012] [Accepted: 10/20/2012] [Indexed: 11/26/2022]
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