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Rieckmann MM, Blake RE, Chang SJ, Laursen KH. An optimized method for extraction and purification of inorganic phosphate from plant material for oxygen isotope ratio analysis. MethodsX 2024; 12:102541. [PMID: 38287963 PMCID: PMC10823127 DOI: 10.1016/j.mex.2023.102541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 12/26/2023] [Indexed: 01/31/2024] Open
Abstract
Compound-specific stable isotope ratio analysis of oxygen isotopes in inorganic phosphate can be used to study biological phosphorus cycling and the transformation processes controlling the fate of phosphorus. However, methods for extraction of inorganic phosphate from plant tissue for oxygen isotope ratio analysis are not consistent. Further, the purification into solid silver phosphate can be challenging and laborious. In this work, a detailed and optimized method to provide a more consistent, easily implementable and reproducible extraction using trichloroacetic acid and subsequent purification of inorganic phosphate from plant material for oxygen isotope ratio analysis is presented. Key focus points were: uniform extraction of inorganic phosphate from barley leaves, removal of dissolved organic material, flexibility in regards to the amount of inorganic phosphate extracted for the purification into silver phosphate, reduced use of chemicals and, removal of co-precipitated oxygen-bearing compounds before analysis. Most notable optimizations to the method and associated effects were:•Drying of plant material before inorganic phosphate extraction increases the method applicability to a broader range of plant sample types.•Removal of dissolved organic matter improves inorganic phosphate purification.•Sample volume adjustment according to inorganic phosphate content is vital for effective and quantitative precipitations.
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Affiliation(s)
- Maria Monrad Rieckmann
- Department of Plant and Environmental Sciences (PLEN), Faculty of Science, Plant and Soil Science Section, Plant Nutrients and Food Quality Research Group, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Copenhagen, Denmark
| | | | - Sae Jung Chang
- Korea Basic Science Institute, Seoul Center, Seoul, South Korea
| | - Kristian Holst Laursen
- Department of Plant and Environmental Sciences (PLEN), Faculty of Science, Plant and Soil Science Section, Plant Nutrients and Food Quality Research Group, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Copenhagen, Denmark
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Li J, Liu H, Liu Z, Zhang X, Blake RE, Huang Z, Cai M, Wang F, Yu C. Transformation mechanism of methylphosphonate to methane by Burkholderia sp: Insight from multi-labeled water isotope probing and transcriptomic. Environ Res 2023; 218:114970. [PMID: 36470350 DOI: 10.1016/j.envres.2022.114970] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 11/25/2022] [Accepted: 11/27/2022] [Indexed: 06/17/2023]
Abstract
Methylphosphonate (MPn), has been identified as a likely source of methane in aerobic ocean and may be responsible for the "ocean methane paradox", that is oversaturation of dissolved methane in oxic sea waters. However, the mechanism underlying the cleavage of C-P bonds during microbial degradation is not well understood. Using multi-labeled water isotope probing (MLWIP) and transcriptome analysis, we investigated the phosphate oxygen isotope systematics and mechanisms of microbial-mediated degradation of MPn in this study. In the aerobic culture containing MPn as the only phosphorus source, there was a significant release of inorganic phosphate (149.4 μmol/L) and free methane (268.3 mg/L). The oxygen isotopic composition of inorganic phosphorus (δ18OP) of accumulated released phosphate was 4.50‰, 23.96‰, and 40.88‰, respectively, in the corresponding 18O-labeled waters of -10.3‰, 9.9‰, and 30.6‰, and the slope obtained in plots of δ18OP versus the oxygen isotopic composition of water (δ18OW) was 0.89. Consequently, 89% of the oxygen atoms (Os) in phosphate (PO4) were exchanged with 18O-labeled waters in the medium, while the rest were exchanged with intracellular metabolic water. It has been confirmed that the C-P bond cleavage of MPn occurs in the cell with both ambient and metabolic water participation. Moreover, phn gene clusters play significant roles to cleave the C-P bond of MPn for Burkholderia sp. HQL1813, in which phnJ, phnM and phnI genes are significantly up-regulated during MPn decomposition to methane. In conclusion, the aerobic biotransformation of MPn to free methane by Burkholderia sp. HQL1813 has been elucidated, providing new insights into the mechanism that bio-cleaves C-P bonds to produce methane aerobically in aqueous environments for representative phosphonates.
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Affiliation(s)
- Junhong Li
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, 430062, Wuhan, China
| | - Houquan Liu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, 430062, Wuhan, China
| | - Zeqin Liu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, 430062, Wuhan, China
| | - Xianhua Zhang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, 430062, Wuhan, China
| | - Ruth Elaine Blake
- Department of Earth and Planetary Sciences, Yale University, New Haven, CT, 06520-8109, USA
| | - Zhiyong Huang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, National Technology Innovation Center of Synthetic Biology, 300308, Tianjin, China
| | - Minmin Cai
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, National Engineering Research Centre of Microbial Pesticides, Huazhong Agricultural University, 430070, Wuhan, China
| | - Fei Wang
- School of Environment, Beijing Normal University, 19 Xinjiekouwai, Haidian District, 100875, Beijing, China.
| | - Chan Yu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, 430062, Wuhan, China.
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Xia C, Geng H, Li X, Zhang Y, Wang F, Tang X, Blake RE, Li H, Chang SJ, Yu C. Mechanism of methylphosphonic acid photo-degradation based on phosphate oxygen isotopes and density functional theory. RSC Adv 2019; 9:31325-31332. [PMID: 35527942 PMCID: PMC9072446 DOI: 10.1039/c9ra05169d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 09/06/2019] [Indexed: 11/21/2022] Open
Abstract
Methylphosphonic acid (MPn) is an intermediate in the synthesis of the phosphorus-containing nerve agents, such as sarin and VX, and a biosynthesis product of marine microbes with ramifications to global climate change and eutrophication. Here, we applied the multi-labeled water isotope probing (MLWIP) approach to investigate the C-P bond cleavage mechanism of MPn under UV irradiation and density functional theory (DFT) to simulate the photo-oxidation reaction process involving reactive oxygen species (ROS). The results contrasted with those of the addition of the ROS-quenching compounds, 2-propanol and NaN3. The degradation kinetics results indicated that the extent of MPn degradation was more under alkaline conditions and that the degradation process was more rapid at the initial stage of the reaction. The phosphate oxygen isotope data confirmed that one exogenous oxygen atom was incorporated into the product orthophosphate (PO4) following the C-P bond cleavage, and the oxygen isotopic composition of this free PO4 was found to vary with pH. The combined results of the ROS-quenching experiments and DFT indicate that the C-P bond was cleaved by OH-/˙OH and not by other reactive oxygen species. Based on these results, we have established a mechanistic model for the photolysis of MPn, which provides new insights into the fate of MPn and other phosphonate/organophosphate compounds in the environment.
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Affiliation(s)
- Congcong Xia
- Jiangxi Transportation Institute China 809 Jinsha Road 330038 Nanchang China
- School of Energy & Environmental Engineering, University of Science and Technology Beijing 30 Xueyuan Road 100083 Beijing China
| | - Huanhuan Geng
- School of Energy & Environmental Engineering, University of Science and Technology Beijing 30 Xueyuan Road 100083 Beijing China
| | - Xiaobao Li
- Jiangxi Transportation Institute China 809 Jinsha Road 330038 Nanchang China
| | - Yiyue Zhang
- School of Energy & Environmental Engineering, University of Science and Technology Beijing 30 Xueyuan Road 100083 Beijing China
| | - Fei Wang
- School of Energy & Environmental Engineering, University of Science and Technology Beijing 30 Xueyuan Road 100083 Beijing China
| | - Xiaowen Tang
- School of Pharmaceutical Sciences, Sun Yet-sen University 510006 Guangzhou China
| | - R E Blake
- School of Energy & Environmental Engineering, University of Science and Technology Beijing 30 Xueyuan Road 100083 Beijing China
- Department of Geology and Geophysics, Yale University P.O. Box 208109 New Haven CT 06520-8109 USA
| | - Hui Li
- Department of Geology and Geophysics, Yale University P.O. Box 208109 New Haven CT 06520-8109 USA
| | - Sae Jung Chang
- Department of Geology and Geophysics, Yale University P.O. Box 208109 New Haven CT 06520-8109 USA
| | - Chan Yu
- School of Energy & Environmental Engineering, University of Science and Technology Beijing 30 Xueyuan Road 100083 Beijing China
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Yu C, Wang F, Chang SJ, Yao J, Blake RE. Phosphate oxygen isotope evidence for methylphosphonate sources of methane and dissolved inorganic phosphate. Sci Total Environ 2018; 644:747-753. [PMID: 29990922 DOI: 10.1016/j.scitotenv.2018.06.382] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 06/21/2018] [Accepted: 06/29/2018] [Indexed: 06/08/2023]
Abstract
The ocean is an important source of methane, however, the sources of oceanic methane and mechanisms of its release to the atmosphere have only recently begun to be understood. Recent studies have identified methylphosphonate (MPn) as a previously unknown and likely source of methane in the aerobic ocean (Karl et al., 2008), as well as shown the biosynthesis of methylphosphonic acid to be a widespread trait in marine microbes (Metcalf et al., 2012). The mechanisms and reaction pathways from MPn to free methane, however, have not been well studied. Here we present results of laboratory studies on the photo-degradation of MPn, a likely mechanism of methane release to the atmosphere and phosphate release to the surface oceans. Phosphonoacetic acid was also studied as an additional model compound for comparison. We used the multi-labeled water isotope probing (MLWIP) approach, involving 18O-labeled waters to probe the photolytic mechanism of CP bond cleavage in phosphates through analysis of P released from MPn as PO4. These studies identified distinct reaction pathways involving phosphates compared with other common organophosphorus compounds (e.g., phosphoesters), as well as suggest the involvement of both ambient water and atmospheric oxygen in CP bond cleavage. There is only a small amount of water oxygen incorporated into product PO4 after cleavage of the CP bond in MPn, suggesting atmospheric O2 or radicals formed from O2 under Ultra Violet Radiation (UVR), as the primary source of O that replaces C in the CP bond of MPn. Model calculations suggest that the δ18OP signature of phosphate released via UV-degradation of phosphates is largely (75%) inherited from the original phosphate substrate. This opens up the possibility of tracing and differentiating specific phosphate sources of dissolved phosphate from other organophosphorus (Porg) sources (e.g., phosphoesters) used in primary production, as well as for tracing specific MPn sources of atmospheric methane.
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Affiliation(s)
- Chan Yu
- Hubei Key Laboratory of Industrial Biotechnology, College of Life Sciences, Hubei University, 430062 Wuhan, China
| | - Fei Wang
- School of Energy & Environmental Engineering, University of Science and Technology Beijing, 100083 Beijing, China
| | - Sae Jung Chang
- Department of Geology and Geophysics, Yale University, New Haven, CT 06520-8109, USA; Seoul Center, Korea Basic Science Institute, Seoul 02841, Republic of Korea
| | - Jun Yao
- School of Water Resources and Environment, University of Geosciences, 100083 Beijing, China
| | - Ruth Elaine Blake
- School of Energy & Environmental Engineering, University of Science and Technology Beijing, 100083 Beijing, China; Department of Geology and Geophysics, Yale University, New Haven, CT 06520-8109, USA.
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Blake RE, Alt JC, Martini AM. Oxygen isotope ratios of PO4: an inorganic indicator of enzymatic activity and P metabolism and a new biomarker in the search for life. Proc Natl Acad Sci U S A 2001; 98:2148-53. [PMID: 11226207 PMCID: PMC30107 DOI: 10.1073/pnas.051515898] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The distinctive relations between biological activity and isotopic effect recorded in biomarkers (e.g., carbon and sulfur isotope ratios) have allowed scientists to suggest that life originated on this planet nearly 3.8 billion years ago. The existence of life on other planets may be similarly identified by geochemical biomarkers, including the oxygen isotope ratio of phosphate (delta(18)O(p)) presented here. At low near-surface temperatures, the exchange of oxygen isotopes between phosphate and water requires enzymatic catalysis. Because enzymes are indicative of cellular activity, the demonstration of enzyme-catalyzed PO(4)-H(2)O exchange is indicative of the presence of life. Results of laboratory experiments are presented that clearly show that delta(18)O(P) values of inorganic phosphate can be used to detect enzymatic activity and microbial metabolism of phosphate. Applications of delta(18)O(p) as a biomarker are presented for two Earth environments relevant to the search for extraterrestrial life: a shallow groundwater reservoir and a marine hydrothermal vent system. With the development of in situ analytical techniques and future planned sample return strategies, delta(18)O(p) may provide an important biosignature of the presence of life in extraterrestrial systems such as that on Mars.
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Affiliation(s)
- R E Blake
- Department of Geology and Geophysics, Yale University, New Haven, CT 06520-8109, USA.
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Simon JA, Robinson DE, Andrews MC, Hildebrand JR, Rocci ML, Blake RE, Hodgen GD. The absorption of oral micronized progesterone: the effect of food, dose proportionality, and comparison with intramuscular progesterone. Fertil Steril 1993; 60:26-33. [PMID: 8513955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
OBJECTIVES To examine the effects of food ingestion and administered dose on the absorption of oral micronized P (Utrogestan; Besins-Iscovesco, Paris, France) and to compare the bioavailability of intramuscular versus oral routes of administration. DESIGN Prospective, randomized, open label crossover protocol with 7 days between dosages. SETTING Academic institution. PARTICIPANTS Fifteen normal postmenopausal women. INTERVENTIONS All subjects participated in three separate protocols: [1] micronized P (200 mg) or placebo under fasting or nonfasting conditions once daily for 5 days; [2] micronized P (100, 200, or 300 mg) once daily under fasting conditions for 5 days; and [3] micronized P (200 mg) or intramuscular P (50 mg in oil) administered once daily for 2 days. MAIN OUTCOME MEASURES Serum P concentrations were measured in all groups. RESULTS Concomitant food ingestion increased the area under the serum P concentration versus time curve (AUC0 to 24) and the maximum serum P concentration (Cmax) without affecting time to maximum serum concentration (Tmax) (P < 0.05). Micronized P absorption and elimination were first-order processes and exhibited dose-independent pharmacokinetics between 100 and 300 mg. After intramuscular P, Cmax was higher and Tmax occurred later compared with the oral P preparation. Oral P had lower relative bioavailability (8.6%) than intramuscular P. CONCLUSIONS Absorption of micronized P was enhanced twofold in the presence of food. Both absorption and elimination were dose-independent, dose proportionality being confirmed. Bioavailability of the oral P was approximately 10% compared with intramuscular P.
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Affiliation(s)
- J A Simon
- Obstetrics and Gynecology, Georgetown University School of Medicine, Washington, D.C. 20007
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Blake RE, Rajguru S, Nolan GH, Ahluwalia BS. Dexamethasone suppresses sex-hormone binding globulin. Fertil Steril 1988; 49:66-70. [PMID: 3121398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Dexamethasone suppression (DEX-S) for 14 days has been used to determine the probable source of androgen excess. The exact mechanism(s) of DEX-S is still unclear. The authors postulated that dexamethasone (DEX) inhibits either the synthesis or secretion of sex-hormone binding globulin (SHBG). To examine this hypothesis, 14 women with polycystic ovarian disease (PCOD) and 3 volunteers were given DEX for 14 days. The PCOD group included obese and nonobese women (+/- 15% ideal body weight). Plasma determinations by radioimmunoassay of total testosterone, free testosterone, androstenedione, dehydroepiandrosterone sulfate, luteinizing hormone; follicle-stimulating hormone; cortisol, and SHBG were made. DEX suppressed SHBG levels (P less than 0.01). SHBG levels were significantly lower in the obese than in the nonobese (P less than 0.01). All androgens were suppressed by DEX, with the exception of androstenedione post-DEX levels, which were significantly greater than pre-DEX levels in 6 of 14 subjects (P greater than 0.05). This observation is consistent with DEX suppression of SHBG.
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Affiliation(s)
- R E Blake
- Department of Obstetrics and Gynecology, Howard University College of Medicine, Washington, D.C. 20060
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Blake RE, Maroulis GB, Sherman BM, Khalil A. Prolactinoma and adrenal androgens. J Reprod Med 1986; 31:675-9. [PMID: 3772886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Theories about the relationship between hyperprolactinemia and hyperandrogenism are conflicting. Several reports assert that prolactin affects the delta 5 and delta 4 pathways through its effect on the activity of 3beta-hydroxysteroid dehydrogenase (3beta-OHSD). We measured delta 5 and delta 4 steroids, prolactin and cortisol in 18 amenorrheic, hyperprolactinemic women before and after resection of prolactinomas. Similar determinations of delta 5: delta 4 steroids were made in a control group of five women. The ratios of individual delta 5: delta 4 steroids were also analyzed. Our results support a modification of delta 5, delta 4 pathways through an effect on the rate-limiting enzyme 3 beta-OHSD. In hyperprolactinemic women the differences between the preoperative and postoperative steroid levels were significant. Further, since the androgens decreased irrespective of the prolactin following surgery, there probably is a factor other than ACTH and prolactin modulating the adrenal androgens.
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Robertson BJ, Blake RE. Tuboplasty: use, resources, and nursing implications. Perioper Nurs Q 1985; 1:49-56. [PMID: 2409550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Blake RE. Preventive podiatry in a Veterans Administration hospital. J Am Podiatry Assoc 1967; 57:78-80. [PMID: 6039780 DOI: 10.7547/87507315-57-2-78] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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