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Housh AB, Noel R, Powell A, Waller S, Wilder SL, Sopko S, Benoit M, Powell G, Schueller MJ, Ferrieri RA. Studies Using Mutant Strains of Azospirillum brasilense Reveal That Atmospheric Nitrogen Fixation and Auxin Production Are Light Dependent Processes. Microorganisms 2023; 11:1727. [PMID: 37512900 PMCID: PMC10383956 DOI: 10.3390/microorganisms11071727] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 06/27/2023] [Accepted: 06/29/2023] [Indexed: 07/30/2023] Open
Abstract
As the use of microbial inoculants in agriculture rises, it becomes important to understand how the environment may influence microbial ability to promote plant growth. This work examines whether there are light dependencies in the biological functions of Azospirillum brasilense, a commercialized prolific grass-root colonizer. Though classically defined as non-phototrophic, A. brasilense possesses photoreceptors that could perceive light conducted through its host's roots. Here, we examined the light dependency of atmospheric biological nitrogen fixation (BNF) and auxin biosynthesis along with supporting processes including ATP biosynthesis, and iron and manganese uptake. Functional mutants of A. brasilense were studied in light and dark environments: HM053 (high BNF and auxin production), ipdC (capable of BNF, deficient in auxin production), and FP10 (capable of auxin production, deficient in BNF). HM053 exhibited the highest rate of nitrogenase activity with the greatest light dependency comparing iterations in light and dark environments. The ipdC mutant showed similar behavior with relatively lower nitrogenase activity observed, while FP10 did not show a light dependency. Auxin biosynthesis showed strong light dependencies in HM053 and FP10 strains, but not for ipdC. Ferrous iron is involved in BNF, and a light dependency was observed for microbial 59Fe2+ uptake in HM053 and ipdC, but not FP10. Surprisingly, a light dependency for 52Mn2+ uptake was only observed in ipdC. Finally, ATP biosynthesis was sensitive to light across all three mutants favoring blue light over red light compared to darkness with observed ATP levels in descending order for HM053 > ipdC > FP10.
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Affiliation(s)
- Alexandra Bauer Housh
- Missouri Research Reactor Center, University of Missouri, Columbia, MO 65211, USA
- Chemistry Department, University of Missouri, Columbia, MO 65211, USA
- Interdisciplinary Plant Group, University of Missouri, Columbia, MO 65211, USA
| | - Randi Noel
- Missouri Research Reactor Center, University of Missouri, Columbia, MO 65211, USA
- Interdisciplinary Plant Group, University of Missouri, Columbia, MO 65211, USA
- Division of Plant Science & Technology, University of Missouri, Columbia, MO 65211, USA
| | - Avery Powell
- Missouri Research Reactor Center, University of Missouri, Columbia, MO 65211, USA
- Interdisciplinary Plant Group, University of Missouri, Columbia, MO 65211, USA
- School of Natural Resources, University of Missouri, Columbia, MO 65211, USA
| | - Spenser Waller
- Missouri Research Reactor Center, University of Missouri, Columbia, MO 65211, USA
- Interdisciplinary Plant Group, University of Missouri, Columbia, MO 65211, USA
- School of Natural Resources, University of Missouri, Columbia, MO 65211, USA
| | - Stacy L Wilder
- Missouri Research Reactor Center, University of Missouri, Columbia, MO 65211, USA
| | - Stephanie Sopko
- Missouri Research Reactor Center, University of Missouri, Columbia, MO 65211, USA
- Department of Biochemistry, University of Missouri, Columbia, MO 65211, USA
| | - Mary Benoit
- Missouri Research Reactor Center, University of Missouri, Columbia, MO 65211, USA
- Division of Plant Science & Technology, University of Missouri, Columbia, MO 65211, USA
| | - Garren Powell
- Missouri Research Reactor Center, University of Missouri, Columbia, MO 65211, USA
- Department of Biochemistry, University of Missouri, Columbia, MO 65211, USA
| | - Michael J Schueller
- Missouri Research Reactor Center, University of Missouri, Columbia, MO 65211, USA
- Chemistry Department, University of Missouri, Columbia, MO 65211, USA
| | - Richard A Ferrieri
- Missouri Research Reactor Center, University of Missouri, Columbia, MO 65211, USA
- Chemistry Department, University of Missouri, Columbia, MO 65211, USA
- Interdisciplinary Plant Group, University of Missouri, Columbia, MO 65211, USA
- Division of Plant Science & Technology, University of Missouri, Columbia, MO 65211, USA
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Kamnev AA, Tugarova AV. Bioanalytical applications of Mössbauer spectroscopy. RUSSIAN CHEMICAL REVIEWS 2021. [DOI: 10.1070/rcr5006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Abstract
Data on the applications of Mössbauer spectroscopy in the transmission (mainly on 57Fe nuclei) and emission (on 57Co nuclei) variants for analytical studies at the molecular level of metal-containing components in a wide range of biological objects (from biocomplexes and biomacromolecules to supramolecular structures, cells, tissues and organisms) and of objects that are participants or products of biological processes, published in the last 15 years are discussed and systematized. The prospects of the technique in its biological applications, including the developing fields (emission variant, use of synchrotron radiation), are formulated.
The bibliography includes 248 references.
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Turkovskaya OV, Golubev SN. The Collection of Rhizosphere Microorganisms: its importance for the study of associative plant-bacterium interactions. Vavilovskii Zhurnal Genet Selektsii 2020; 24:315-324. [PMID: 33659814 PMCID: PMC7716537 DOI: 10.18699/vj20.623] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Microbial culture collections are very important components of biological science. They provide researchers with material for studies and preserve biological resources. One such collection is the Collection of Rhizosphere Microorganisms, kept at the Institute of Biochemistry and Physiology of Plants and Microorganisms of the Russian Academy of Sciences, Saratov (IBPPM). Its activity is primarily directed toward the isolation and preservation of microorganisms from the plant root zone. The international research interest in microorganisms from this ecological niche is not waning, because they are very important for plant growth and development and, consequently, for plant breeding. The group of bacteria with properties of significance for plants has been given the name "plant-growth-promoting rhizobacteria" (PGPR). This group includes nitrogen-fixing soil alpha-proteobacteria of the genus Azospirillum, which form the core of the IBPPM collection. First discovered by Brazilian scientists in the 1970s, azospirilla are now a universally recognized model object for studying the molecular mechanisms underlying plant-bacterium interactions. The broad range of useful properties found in these microorganisms, including the fixation of atmospheric nitrogen, production of phytohormones, solubilization of phosphates, control of pathogens, and formation of induced systemic resistance in the colonized plants, make these bacteria an all-purpose tool that has been used for several decades in basic and applied research. This article reviews the current state of Azospirillum research, with emphasis on the results obtained at the IBPPM. Scientific expeditions across the Saratov region undertaken by IBPPM microbiologists in the early 1980s formed the basis for the unique collection of members of this bacterial taxon. Currently, the collection has more than 160 Azospirillum strains and is one of the largest collections in Europe. The research conducted at the IBPPM is centered mostly on the Azospirillum structures involved in associative symbiosis with plants, primarily extracellular polysaccharide-containing complexes and lectins. The development of immunochemical methods contributed much to our understanding of the overall organization of the surface of rhizosphere bacteria. The extensive studies of the Azospirillum genome largely deepened our understanding of the role of the aforesaid bacterial structures, motility, and biofilms in the colonization of host plant roots. Of interest are also applied studies focusing on agricultural and environmental technologies and on the "green" synthesis of Au, Ag, and Se nanoparticles. The Collection of Rhizosphere Microorganisms continues to grow, being continually supplemented with newly isolated strains. The data presented in this article show the great importance of specialized microbial culture repositories, such as the IBPPM collection, for the development and maintenance of the microbial research base and for the effective solution of basic and applied tasks in microbiology.
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Affiliation(s)
- O V Turkovskaya
- Institute of Biochemistry and Physiology of Plants and Microorganisms of the Russian Academy of Sciences, Saratov, Russia
| | - S N Golubev
- Institute of Biochemistry and Physiology of Plants and Microorganisms of the Russian Academy of Sciences, Saratov, Russia
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Kamnev AA, Tugarova AV, Shchelochkov AG, Kovács K, Kuzmann E. Diffuse reflectance infrared Fourier transform (DRIFT) and Mössbauer spectroscopic study of Azospirillum brasilense Sp7: Evidence for intracellular iron(II) oxidation in bacterial biomass upon lyophilisation. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2020; 229:117970. [PMID: 31887674 DOI: 10.1016/j.saa.2019.117970] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Revised: 12/17/2019] [Accepted: 12/17/2019] [Indexed: 06/10/2023]
Abstract
Microbial cells are well known to be capable of remaining viable when desiccated, and a variety of beneficial microorganisms can thus be preserved for storage. For the ubiquitous widely studied soil bacterium Azospirillum brasilense (wild-type strain Sp7), which has a significant agrobiotechnological potential owing to its plant-growth-promoting capabilities perspective for its use in biofertilisers, Fourier transform infrared (FTIR) spectroscopy (in the diffuse reflectance mode, DRIFT) was used to control the state of biomass, together with 57Fe transmission Mössbauer spectroscopy to monitor intracellular iron speciation in live rapidly frozen cell suspension and in the lyophilised biomass (both measured at T = 80 K). It has been shown for the first time that a relatively large part of ferrous iron in live cells (22% of the whole cellular iron pool, represented by two high-spin Fe(II) forms, in the 18-h culture grown on 57Fe(III) complex with nitrilotriacetic acid as the sole source of iron) gets largely oxidised upon lyophilisation. The remaining part of iron(II) in the resulting dry biomass was found to be ca. 3% only. The major part of ferric iron in the dry biomass was shown to be comprised of ferritin-like ferric species (giving a typical magnetically split sextet at T = 5 K), while the iron(III) formed from cellular iron(II) by oxidation in air in the course of drying remained in a paramagnetic state even at T = 5 K. The possibility of intracellular iron(II) oxidation to iron(III) upon desiccation may be a specific natural strategy to avoid cell damage caused by Fenton-type reactions in dormant (frozen, dried) cells. The results obtained may have important implications related to iron speciation and redox transformations in dried bacterial preparations intended for long-term storage.
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Affiliation(s)
- Alexander A Kamnev
- Laboratory of Biochemistry, Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, Prosp. Entuziastov, 13, Saratov 410049, Russia.
| | - Anna V Tugarova
- Laboratory of Biochemistry, Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, Prosp. Entuziastov, 13, Saratov 410049, Russia
| | - Alexei G Shchelochkov
- Laboratory of Biochemistry, Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, Prosp. Entuziastov, 13, Saratov 410049, Russia
| | - Krisztina Kovács
- Laboratory of Nuclear Chemistry, Institute of Chemistry, Eötvös Loránd University, P.O. Box 32, Budapest 1512, Hungary
| | - Ernő Kuzmann
- Laboratory of Nuclear Chemistry, Institute of Chemistry, Eötvös Loránd University, P.O. Box 32, Budapest 1512, Hungary
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Tugarova AV, Mamchenkova PV, Khanadeev VA, Kamnev AA. Selenite reduction by the rhizobacterium Azospirillum brasilense, synthesis of extracellular selenium nanoparticles and their characterisation. N Biotechnol 2020; 58:17-24. [PMID: 32184193 DOI: 10.1016/j.nbt.2020.02.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 02/24/2020] [Accepted: 02/29/2020] [Indexed: 01/25/2023]
Abstract
Microbial reduction of selenium oxyanions has attracted attention in recent years. In this study, an original and simple method for the synthesis of extracellular selenium nanoparticles (Se NPs) of relatively uniform size has been developed using strains Sp7 and Sp245 of the ubiquitous plant-growth promoting rhizobacterium Azospirillum brasilense, both capable of selenite (SeO32-) reduction. In addition, a reliable purification protocol for the recovery of the Se NPs has been perfected, which could be applied with minor modifications to cultures of other microbial species. Importantly, it was found that, by changing the conditions of bacterial reduction of selenite, extracellularly localised Se NPs can be obtained using bacteria which would otherwise produce intracellular Se NPs. In particular, bacterial cultures grown up to the end of the logarithmic growth phase, washed free of culture medium and then incubated with selenite, were used to obtain extracellular Se NPs. Their sizes depended on the initial selenite concentration (∼25-80 nm in diameter at 50-10 mM selenite, respectively). The Se NPs obtained were characterised by transmission electron microscopy (TEM), dynamic light scattering, as well as Raman and UV-vis spectroscopies. Their zeta potential was found to be negative (ca. minus 21-24 mV). Bacterial selenite reduction was also studied in the presence of the efflux pump inhibitor carbonyl cyanide m-chlorophenylhydrazone (CCCP). In this case, TEM indicated the formation only of intracellular selenium crystallites. The data show that the formation of extracellular Se NPs requires normal bacterial metabolic activity, while CCCP evidently blocks the membrane export of Se0 nuclei.
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Affiliation(s)
- Anna V Tugarova
- Laboratory of Biochemistry, Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, 13 Prosp. Entuziastov, 410049, Saratov, Russia.
| | - Polina V Mamchenkova
- Laboratory of Biochemistry, Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, 13 Prosp. Entuziastov, 410049, Saratov, Russia
| | - Vitaly A Khanadeev
- Laboratory of Nanobiotechnology, Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, 13 Prosp. Entuziastov, 410049, Saratov, Russia
| | - Alexander A Kamnev
- Laboratory of Biochemistry, Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, 13 Prosp. Entuziastov, 410049, Saratov, Russia.
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Kamnev AA, Tugarova AV. Sample treatment in Mössbauer spectroscopy for protein-related analyses: Nondestructive possibilities to look inside metal-containing biosystems. Talanta 2017; 174:819-837. [PMID: 28738659 DOI: 10.1016/j.talanta.2017.06.057] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 06/01/2017] [Accepted: 06/19/2017] [Indexed: 01/07/2023]
Abstract
In this review, the unique possibilities are considered of the 57Fe transmission (TMS) and 57Co emission (EMS) variants of Mössbauer (nuclear γ-resonance) spectroscopy as nondestructive techniques with minimal sample preparation/treatment and a significant analytical potential, with a focus on the analysis of cation-binding sites in metalloproteins. The techniques are shown to provide unique structural and quantitative information on the coordination microenvironment, the chemical state and transformations of the Mössbauer nuclides in sophisticated metal-containing proteins, including those within complicated supramolecular structures, and in microbial cells or tissues. Recent representative examples of analyses of Fe-containing proteins by 57Fe TMS are briefly discussed, along with the newly emerging data on using 57Co EMS for probing the structural organisation of 57Co-doped cation-binding sites in sophisticated biocomplexes including metalloenzymes. Finally, some rare or exotic applications of Mössbauer spectroscopy (including the synchrotron-based methodology) in protein-related studies are outlined.
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Affiliation(s)
- Alexander A Kamnev
- Laboratory of Biochemistry, Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, 13 Prosp. Entuziastov, 410049, Saratov, Russia.
| | - Anna V Tugarova
- Laboratory of Biochemistry, Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, 13 Prosp. Entuziastov, 410049, Saratov, Russia
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