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Khan A, Liu G, Zhang G, Li X. Radiation-resistant bacteria in desiccated soil and their potentiality in applied sciences. Front Microbiol 2024; 15:1348758. [PMID: 38894973 PMCID: PMC11184166 DOI: 10.3389/fmicb.2024.1348758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Accepted: 05/17/2024] [Indexed: 06/21/2024] Open
Abstract
A rich diversity of radiation-resistant (Rr) and desiccation-resistant (Dr) bacteria has been found in arid habitats of the world. Evidence from scientific research has linked their origin to reactive oxygen species (ROS) intermediates. Rr and Dr. bacteria of arid regions have the potential to regulate imbalance radicals and evade a higher dose of radiation and oxidation than bacterial species of non-arid regions. Photochemical-activated ROS in Rr bacteria is run through photo-induction of electron transfer. A hypothetical model of the biogeochemical cycle based on solar radiation and desiccation. These selective stresses generate oxidative radicals for a short span with strong reactivity and toxic effects. Desert-inhibiting Rr bacteria efficiently evade ROS toxicity with an evolved antioxidant system and other defensive pathways. The imbalanced radicals in physiological disorders, cancer, and lung diseases could be neutralized by a self-sustaining evolved Rr bacteria antioxidant system. The direct link of evolved antioxidant system with intermediate ROS and indirect influence of radiation and desiccation provide useful insight into richness, ecological diversity, and origin of Rr bacteria capabilities. The distinguishing features of Rr bacteria in deserts present a fertile research area with promising applications in the pharmaceutical industry, genetic engineering, biological therapy, biological transformation, bioremediation, industrial biotechnology, and astrobiology.
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Affiliation(s)
- Asaf Khan
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou, China
| | - Guangxiu Liu
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou, China
- Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China
| | - Gaosen Zhang
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou, China
- Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China
| | - Xiangkai Li
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China
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Benditkis AS, Ashikhmin AA, Moskalenko AA, Krasnovsky AA. Photogeneration and quenching of singlet molecular oxygen by bacterial C 40 carotenoids with long chain of conjugated double bonds. PHOTOSYNTHESIS RESEARCH 2024; 159:291-301. [PMID: 38315423 DOI: 10.1007/s11120-023-01070-6] [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: 06/12/2023] [Accepted: 12/14/2023] [Indexed: 02/07/2024]
Abstract
Measurement of photosensitized luminescence of singlet oxygen has been applied to studies of singlet oxygen generation and quenching by C40 carotenoids (neurosporene, lycopene, rhodopin, and spirilloxanthin) with long chain of conjugated double bonds (CDB) using hexafluorobenzene as a solvent. It has been found that neurosporene, lycopene, and rhodopin are capable of the low efficient singlet oxygen generation in aerated solutions upon photoexcitation in the spectral region of their main absorption maxima. The quantum yield of this process was estimated to be (1.5-3.0) × 10-2. This value is near the singlet oxygen yields in solutions of ζ-carotene (7 CDB) and phytoene (3 CDB) and many-fold smaller than in solutions of phytofluene (5 CDB) (Ashikhmin et al. Biochemistry (Mosc) 85:773-780, https://doi.org/10.1134/S0006297920070056 , 2020, Biochemistry (Mosc) 87:1169-1178, 2022, https://doi.org/10.1134/S00062979221001082022 ). Photogeneration of singlet oxygen was not observed in spirilloxanthin solutions. A correlation was found between the singlet oxygen yields and the quantum yields and lifetimes of the fluorescence of the carotenoid molecules. All carotenoids were shown to be strong physical quenchers of singlet oxygen. The rate constants of 1O2 quenching by the carotenoids with long chain of CDB (9-13) were close to the rate constant of the diffusion-limited reactions ≈1010 M-1 s-1, being many-fold greater than the rate constants of 1O2 quenching by the carotenoids with the short chain of CDB (3-7) phytoene, phytofluene, and ζ-carotene studied in prior papers of our group (Ashikhmin et al. 2020, 2022). To our knowledge, the quenching rate constants of rhodopin and spirilloxanthin have been obtained in this paper for the first time. The mechanisms of 1O2 photogeneration by carotenoids in solution and in the LH2 complexes of photosynthetic cells, as well as the efficiencies of their protective action are discussed.
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Affiliation(s)
- A S Benditkis
- A.N. Bach Institute of Biochemistry, Federal Research Center of Biotechnology of the Russian Academy of Sciences, 119071, Moscow, Russia
| | - A A Ashikhmin
- Pushchino Scientific Center for Biological Research of Russian Academy of Sciences, Institute of Basic Biological Problems, Russian Academy of Sciences, 142290, Pushchino, Russia
| | - A A Moskalenko
- Pushchino Scientific Center for Biological Research of Russian Academy of Sciences, Institute of Basic Biological Problems, Russian Academy of Sciences, 142290, Pushchino, Russia
| | - A A Krasnovsky
- A.N. Bach Institute of Biochemistry, Federal Research Center of Biotechnology of the Russian Academy of Sciences, 119071, Moscow, Russia.
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Ma ZX, Feng CX, Song YZ, Sun J, Shao Y, Song SZ, Wan B, Zhang C, Fan H, Bao K, Yang S. Engineering photo-methylotrophic Methylobacterium for enhanced 3-hydroxypropionic acid production during non-growth stage fermentation. BIORESOURCE TECHNOLOGY 2024; 393:130104. [PMID: 38008225 DOI: 10.1016/j.biortech.2023.130104] [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: 10/18/2023] [Revised: 11/23/2023] [Accepted: 11/23/2023] [Indexed: 11/28/2023]
Abstract
This study explored the potential of methanol as a sustainable feedstock for biomanufacturing, focusing on Methylobacterium extorquens, a well-established representative of methylotrophic cell factories. Despite this bacterium's long history, its untapped photosynthetic capabilities for production enhancement have remained unreported. Using genome-scale flux balance analysis, it was hypothesized that introducing photon fluxes could boost the yield of 3-hydroxypropionic acid (3-HP), an energy- and reducing equivalent-consuming chemicals. To realize this, M. extorquens was genetically modified by eliminating the negative regulator of photosynthesis, leading to improved ATP levels and metabolic activity in non-growth cells during a two-stage fermentation process. This modification resulted in a remarkable 3.0-fold increase in 3-HP titer and a 2.1-fold increase in its yield during stage (II). Transcriptomics revealed that enhanced light-driven methanol oxidation, NADH transhydrogenation, ATP generation, and fatty acid degradation were key factors. This development of photo-methylotrophy as a platform technology introduced novel opportunities for future production enhancements.
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Affiliation(s)
- Zeng-Xin Ma
- School of Life Sciences, Shandong Province Key Laboratory of Applied Mycology, and Qingdao International Center on Microbes Utilizing Biogas, Qingdao Agricultural University, Qingdao 266109, Shandong, People's Republic of China
| | - Chen-Xi Feng
- School of Life Sciences, Shandong Province Key Laboratory of Applied Mycology, and Qingdao International Center on Microbes Utilizing Biogas, Qingdao Agricultural University, Qingdao 266109, Shandong, People's Republic of China
| | - Ya-Zhen Song
- School of Life Sciences, Shandong Province Key Laboratory of Applied Mycology, and Qingdao International Center on Microbes Utilizing Biogas, Qingdao Agricultural University, Qingdao 266109, Shandong, People's Republic of China
| | - Jing Sun
- School of Life Sciences, Shandong Province Key Laboratory of Applied Mycology, and Qingdao International Center on Microbes Utilizing Biogas, Qingdao Agricultural University, Qingdao 266109, Shandong, People's Republic of China
| | - Yi Shao
- School of Life Sciences, Shandong Province Key Laboratory of Applied Mycology, and Qingdao International Center on Microbes Utilizing Biogas, Qingdao Agricultural University, Qingdao 266109, Shandong, People's Republic of China
| | - Shu-Zhen Song
- School of Life Sciences, Shandong Province Key Laboratory of Applied Mycology, and Qingdao International Center on Microbes Utilizing Biogas, Qingdao Agricultural University, Qingdao 266109, Shandong, People's Republic of China
| | - Bin Wan
- School of Life Sciences, Shandong Province Key Laboratory of Applied Mycology, and Qingdao International Center on Microbes Utilizing Biogas, Qingdao Agricultural University, Qingdao 266109, Shandong, People's Republic of China
| | - Cong Zhang
- School of Life Sciences, Shandong Province Key Laboratory of Applied Mycology, and Qingdao International Center on Microbes Utilizing Biogas, Qingdao Agricultural University, Qingdao 266109, Shandong, People's Republic of China
| | - Huan Fan
- Tianjin Key Laboratory of Animal Molecular Breeding and Biotechnology, Tianjin Engineering Research Center of Animal Healthy Farming, Institute of Animal Science and Veterinary, Tianjin Academy of Agricultural Sciences, Tianjin 300381, People's Republic of China
| | - Kai Bao
- School of Life Sciences, Hubei University, Wuhan 430062, Hubei, People's Republic of China
| | - Song Yang
- School of Life Sciences, Shandong Province Key Laboratory of Applied Mycology, and Qingdao International Center on Microbes Utilizing Biogas, Qingdao Agricultural University, Qingdao 266109, Shandong, People's Republic of China; Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin University, Tianjin 300072, People's Republic of China.
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Yanykin D, Paskhin M, Ashikhmin AA, Bolshakov MA. Carotenoid-dependent singlet oxygen photogeneration in light-harvesting complex 2 of Ectothiorhodospira haloalkaliphila leads to the formation of organic hydroperoxides and damage to both pigments and protein matrix. PeerJ 2024; 12:e16615. [PMID: 38250719 PMCID: PMC10798160 DOI: 10.7717/peerj.16615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 11/15/2023] [Indexed: 01/23/2024] Open
Abstract
Earlier, it was suggested that carotenoids in light-harvesting complexes 2 (LH2) can generate singlet oxygen, further oxidizing bacteriochlorophyll to 3-acetyl-chlorophyll. In the present work, it was found that illumination of isolated LH2 preparations of purple sulfur bacterium Ectothiorhodospira haloalkaliphila with light in the carotenoid absorption region leads to the photoconsumption of molecular oxygen, which is accompanied by the formation of hydroperoxides of organic molecules in the complexes. Photoformation of two types of organic hydroperoxides were revealed: highly lipophilic (12 molecules per one LH2) and relatively hydrophobic (68 per one LH2). It has been shown that illumination leads to damage to light-harvesting complexes. On the one hand, photobleaching of bacteriochlorophyll and a decrease in its fluorescence intensity are observed. On the other hand, the photoinduced increase in the hydrodynamic radius of the complexes, the reduction in their thermal stability, and the change in fluorescence intensity indicate conformational changes occurring in the protein molecules of the LH2 preparations. Inhibition of the processes described above upon the addition of singlet oxygen quenchers (L-histidine, Trolox, sodium L-ascorbate) may support the hypothesis that carotenoids in LH2 preparations are capable of generating singlet oxygen, which, in turn, damage to protein molecules.
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Affiliation(s)
- Denis Yanykin
- Institute of Basic Biological Problems, FRC PSCBR, Pushchino, Moscow, Russia
- Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow, Moscow, Russia
| | - Mark Paskhin
- Institute of Basic Biological Problems, FRC PSCBR, Pushchino, Moscow, Russia
- Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow, Moscow, Russia
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Wolnicka-Glubisz A, Wisniewska-Becker A. Dual Action of Curcumin as an Anti- and Pro-Oxidant from a Biophysical Perspective. Antioxidants (Basel) 2023; 12:1725. [PMID: 37760028 PMCID: PMC10525529 DOI: 10.3390/antiox12091725] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 08/30/2023] [Accepted: 09/04/2023] [Indexed: 09/29/2023] Open
Abstract
Curcumin, a natural polyphenol widely used as a spice, colorant and food additive, has been shown to have therapeutic effects against different disorders, mostly due to its anti-oxidant properties. Curcumin also reduces the efficiency of melanin synthesis and affects cell membranes. However, curcumin can act as a pro-oxidant when blue light is applied, since upon illumination it can generate singlet oxygen. Our review aims to describe this dual role of curcumin from a biophysical perspective, bearing in mind its concentration, bioavailability-enhancing modifications and membrane interactions, as well as environmental conditions such as light. In low concentrations and without irradiation, curcumin shows positive effects and can be recommended as a beneficial food supplement. On the other hand, when used in excess or irradiated, curcumin can be toxic. Therefore, numerous attempts have been undertaken to test curcumin as a potential photosensitizer in photodynamic therapy (PDT). At that point, we underline that curcumin-based PDT is limited to the treatment of superficial tumors or skin and oral infections due to the weak penetration of blue light. Additionally, we conclude that an increase in curcumin bioavailability through the using nanocarriers, and therefore its concentration, as well as its topical use if skin is exposed to light, may be dangerous.
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Affiliation(s)
- Agnieszka Wolnicka-Glubisz
- Department of Biophysics and Cancer Biology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Krakow, Poland
| | - Anna Wisniewska-Becker
- Department of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Krakow, Poland
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Ashikhmin AA, Benditkis AS, Moskalenko AA, Krasnovsky AA. ζ-Carotene: Generation and Quenching of Singlet Oxygen, Comparison with Phytofluene. BIOCHEMISTRY (MOSCOW) 2022; 87:1169-1178. [DOI: 10.1134/s0006297922100108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Makhneva ZK, Smolova TN, Bolshakov MA, Moskalenko AA. LH2 Complex from Sulfur Bacteria Allochromatium vinosum – Natural Singlet Oxygen Sensor. BIOCHEMISTRY (MOSCOW) 2022; 87:1159-1168. [DOI: 10.1134/s0006297922100091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Makhneva ZK, Moskalenko AA. Carotenoids in LH2 Complexes from Allochromatium vinosum under Illumination Are Able to Generate Singlet Oxygen Which Oxidizes BChl850. Microbiology (Reading) 2022. [DOI: 10.1134/s002626172230021x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Zbyradowski M, Duda M, Wisniewska-Becker A, Heriyanto, Rajwa W, Fiedor J, Cvetkovic D, Pilch M, Fiedor L. Triplet-driven chemical reactivity of β-carotene and its biological implications. Nat Commun 2022; 13:2474. [PMID: 35513374 PMCID: PMC9072317 DOI: 10.1038/s41467-022-30095-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 04/14/2022] [Indexed: 11/09/2022] Open
Abstract
The endoperoxides of β-carotene (βCar-EPOs) are regarded as main products of the chemical deactivation of 1O2 by β-carotene, one of the most important antioxidants, following a concerted singlet-singlet reaction. Here we challenge this view by showing that βCar-EPOs are formed in the absence of 1O2 in a non-concerted triplet-triplet reaction: 3O2 + 3β-carotene → βCar-EPOs, in which 3β-carotene manifests a strong biradical character. Thus, the reactivity of β-carotene towards oxygen is governed by its excited triplet state. βCar-EPOs, while being stable in the dark, are photochemically labile, and are a rare example of nonaromatic endoperoxides that release 1O2, again not in a concerted reaction. Their light-induced breakdown triggers an avalanche of free radicals, which accounts for the pro-oxidant activity of β-carotene and the puzzling swap from its anti- to pro-oxidant features. Furthermore, we show that βCar-EPOs, and carotenoids in general, weakly sensitize 1O2. These findings underlie the key role of the triplet state in determining the chemical and photophysical features of β-carotene. They shake up the prevailing models of carotenoid photophysics, the anti-oxidant functioning of β-carotene, and the role of 1O2 in chemical signaling in biological photosynthetic systems. βCar-EPOs and their degradation products are not markers of 1O2 and oxidative stress but of the overproduction of extremely hazardous chlorophyll triplets in photosystems. Hence, the chemical signaling of overexcitation of the photosynthetic apparatus is based on a 3chlorophyll-3β-carotene relay, rather than on extremely short-lived 1O2.
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Affiliation(s)
- Mateusz Zbyradowski
- Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387, Cracow, Poland
| | - Mariusz Duda
- Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387, Cracow, Poland
| | - Anna Wisniewska-Becker
- Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387, Cracow, Poland
| | - Heriyanto
- Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387, Cracow, Poland.,Ma Chung Research Center for Photosynthetic Pigments, Ma Chung University, Villa Puncak Tidar N-01, Malang, 65151, Indonesia
| | - Weronika Rajwa
- Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387, Cracow, Poland
| | - Joanna Fiedor
- Faculty of Physics and Applied Computer Science, AGH-University of Science and Technology, Mickiewicza 30, 30-059, Cracow, Poland
| | - Dragan Cvetkovic
- Faculty of Technology, University of Niš, 16000, Leskovac, Serbia
| | - Mariusz Pilch
- Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387, Cracow, Poland.,Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387, Kraków, Poland
| | - Leszek Fiedor
- Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387, Cracow, Poland.
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Makhneva ZK, Bolshakov MA, Moskalenko AA. Carotenoids Do Not Protect Bacteriochlorophylls in Isolated Light-Harvesting LH2 Complexes of Photosynthetic Bacteria from Destructive Interactions with Singlet Oxygen. Molecules 2021; 26:5120. [PMID: 34500552 PMCID: PMC8434301 DOI: 10.3390/molecules26175120] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 08/18/2021] [Accepted: 08/20/2021] [Indexed: 11/22/2022] Open
Abstract
The effect of singlet oxygen on light-harvesting (LH) complexes has been studied for a number of sulfur (S+) and nonsulfur (S-) photosynthetic bacteria. The visible/near-IR absorption spectra of the standard LH2 complexes (B800-850) of Allochromatium (Alc.) vinosum (S+), Rhodobacter (Rba.) sphaeroides (S-), Rhodoblastus (Rbl.) acidophilus (S-), and Rhodopseudomonas (Rps.) palustris (S-), two types LH2/LH3 (B800-850 and B800-830) of Thiorhodospira (T.) sibirica (S+), and an unusual LH2 complex (B800-827) of Marichromatium (Mch.) purpuratum (S+) or the LH1 complex from Rhodospirillum (Rsp.) rubrum (S-) were measured in aqueous buffer suspensions in the presence of singlet oxygen generated by the illumination of the dye Rose Bengal (RB). The content of carotenoids in the samples was determined using HPLC analysis. The LH2 complex of Alc. vinosum and T. sibirica with a reduced content of carotenoids was obtained from cells grown in the presence of diphenylamine (DPA), and LH complexes were obtained from the carotenoidless mutant of Rba. sphaeroides R26.1 and Rps. rubrum G9. We found that LH2 complexes containing a complete set of carotenoids were quite resistant to the destructive action of singlet oxygen in the case of Rba. sphaeroides and Mch. purpuratum. Complexes of other bacteria were much less stable, which can be judged by a strong irreversible decrease in the bacteriochlorophyll (BChl) absorption bands (at 850 or 830 nm, respectively) for sulfur bacteria and absorption bands (at 850 and 800 nm) for nonsulfur bacteria. Simultaneously, we observe the appearance of the oxidized product 3-acetyl-chlorophyll (AcChl) absorbing near 700 nm. Moreover, a decrease in the amount of carotenoids enhanced the spectral stability to the action of singlet oxygen of the LH2 and LH3 complexes from sulfur bacteria and kept it at the same level as in the control samples for carotenoidless mutants of nonsulfur bacteria. These results are discussed in terms of the current hypothesis on the protective functions of carotenoids in bacterial photosynthesis. We suggest that the ability of carotenoids to quench singlet oxygen (well-established in vitro) is not well realized in photosynthetic bacteria. We compared the oxidation of BChl850 in LH2 complexes of sulfur bacteria under the action of singlet oxygen (in the presence of 50 μM RB) or blue light absorbed by carotenoids. These processes are very similar: {[BChl + (RB or carotenoid) + light] + O2} → AcChl. We speculate that carotenoids are capable of generating singlet oxygen when illuminated. The mechanism of this process is not yet clear.
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Affiliation(s)
| | | | - Andrey A. Moskalenko
- Institute of Basic Biological Problems RAS, 142290 Pushchino, Russia; (Z.K.M.); (M.A.B.)
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Dong D, Sun H, Qi Z, Liu X. Improving microbial bioremediation efficiency of intensive aquacultural wastewater based on bacterial pollutant metabolism kinetics analysis. CHEMOSPHERE 2021; 265:129151. [PMID: 33302206 DOI: 10.1016/j.chemosphere.2020.129151] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 10/28/2020] [Accepted: 11/27/2020] [Indexed: 06/12/2023]
Abstract
How to effectively bioremediate aquacultural wastewater using microbes is an urgent issue for the application of aquaculture beneficial microorganisms. Purple non-sulfur bacteria (PNSB) are beneficial in preventing related pollution in aquaculture applications. An autochthonous PNSB Rhodobacter sphaeroides was employed in this study to explore an effective bioremediation strategy of aquacultural wastewater. The test bacterium showed high performance in the removal of ammonium (97.50% ± 0.78% of 42 mg L-1 NH4+-N) and phosphate (93.24% ± 0.71% of 50 mg L-1 PO43--P) in the synthetic wastewater, which are the two crucial indicators of the aquacultural wastewater bioremediation. The study also unveiled that the imbalanced ratio of nutrients in water was the principal reason for limiting the efficient bioremediation of shrimp-culture wastewater. Therefore, an effective microbial bioremediation strategy was proposed by comprehensively considering bacterial pollutant metabolism kinetics constants such as specific consumption yields of chemical oxygen demand (COD)/phosphorous and nitrogen/phosphorous. Finally, COD, total nitrogen (TN), total phosphorus (TP), and ammonium (NH4+-N) in the wastewater were examined, and the results showed that they all decreased to the acceptable values. In conclusion, this study suggested a novel method for improved bioremediation efficiency of aquacultural wastewater, and the findings revealed that this strategy is promising due to its characteristics to be used in various aquaculture wastewater types.
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Affiliation(s)
- Die Dong
- State Key Laboratory of Bio-based Material and Green Papermaking (LBMP), Qilu University of Technology (Shandong Academy of Sciences), Jinan, Shandong, PR China
| | - Haoyu Sun
- State Key Laboratory of Bio-based Material and Green Papermaking (LBMP), Qilu University of Technology (Shandong Academy of Sciences), Jinan, Shandong, PR China; Key Laboratory of Shandong Microbial Engineering, College of Bioengineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, Shandong, PR China
| | - Zhengliang Qi
- Key Laboratory of Shandong Microbial Engineering, College of Bioengineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, Shandong, PR China.
| | - Xinli Liu
- State Key Laboratory of Bio-based Material and Green Papermaking (LBMP), Qilu University of Technology (Shandong Academy of Sciences), Jinan, Shandong, PR China; Key Laboratory of Shandong Microbial Engineering, College of Bioengineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, Shandong, PR China
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Ashikhmin AA, Benditkis AS, Moskalenko AA, Krasnovsky AA. Phytofluene as a Highly Efficient UVA Photosensitizer of Singlet Oxygen Generation. BIOCHEMISTRY (MOSCOW) 2020; 85:773-780. [PMID: 33040721 DOI: 10.1134/s0006297920070056] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Phytoene and phytofluene - uncolored C40 carotenoids with short chain of conjugated double bonds (3 and 5, respectively) - are known to be universal precursors in biosynthesis of colored carotenoids in photosynthesizing organisms. It is commonly recognized that C40 carotenoids are photoprotectors of cells and tissues. We have shown that phytofluene is an exception to this rule. By measuring photosensitized phosphorescence of singlet oxygen (1O2) we found out that phytofluene was very effective photosensitizer of 1O2 formation in aerated solutions under UVA irradiation (quantum yield of 85 ± 5%), whereas phytoene was almost inactive in this process. It was demonstrated that both carotenoids quench singlet oxygen in the dark. The obtained quenching rate constants [(4 ± 1) × 106 M-1·s-1 for phytoene and (2 ± 0.5) × 107 M-1·s-1 for phytofluene] were smaller than the rate constant of the diffusion-controlled reactions by 3-4 orders of magnitude. Thus, both carotenoids displayed rather weak protector properties. Moreover, phytofluene due to its high photosensitizing activity might be considered as a promoter of cell photodamage and a promising UVA photosensitizer for medical purposes.
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Affiliation(s)
- A A Ashikhmin
- Institute of Basic Biological Problems, Federal Research Center "Pushchino Scientific Center for Biological Research, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia.
| | - A S Benditkis
- Bach Institute of Biochemistry, Federal Research Center of Biotechnology, Russian Academy of Sciences, Moscow, 119071, Russia.
| | - A A Moskalenko
- Institute of Basic Biological Problems, Federal Research Center "Pushchino Scientific Center for Biological Research, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia.
| | - A A Krasnovsky
- Bach Institute of Biochemistry, Federal Research Center of Biotechnology, Russian Academy of Sciences, Moscow, 119071, Russia.
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