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3. Ethanol Enhances Astaxanthin Production by Aurantiochytrium sp

Author

Sakamoto, Takaiku, Ikeda, Yusuke, Masuda, Naruho, and Sakuradani, Eiji

Subjects
astaxanthin, ethanol stress, β-carotene, Aurantiochytrium
Abstract

Two-percent ethanol increased the astaxanthin productivity of heterotrophic microalgae Aurantiochytrium sp. O5-1-1 to 2.231 mg/L, 45-fold higher than under ethanol-free condition. Ethanol in the medium decreased at the same rate as spontaneous volatilization, suggesting that it was not a transient signaling factor but a continuous stress on the cells. The triply mutated strain OM3-3 produced 5.075 mg/L astaxanthin under 2% ethanol conditions. Furthermore, the astaxanthin accumulation of the mutant OM3-9 was 0.895 mg/g, which was 150-fold higher than that of strain O5-1-1 in ethanol-free condition. These results are beneficial for the commercial exploitation of carotenoids producing Aurantiochytrium spp.

Published
2023

11. Isolation and characterization of indigo-reducing bacteria and analysis of microbiota from indigo fermentation suspensions

Author

Nakagawa, Kasumi, primary, Takeuchi, Michiki, additional, Tada, Manami, additional, Matsunaga, Momoka, additional, Kugo, Masami, additional, Kiyofuji, Suzuna, additional, Kikuchi, Mayu, additional, Yomota, Kazuya, additional, Sakamoto, Takaiku, additional, Kano, Kenji, additional, Ogawa, Jun, additional, and Sakuradani, Eiji, additional

Published
2021
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12. Simultaneous Imaging and Characterization of Polyunsaturated Fatty Acids, Carotenoids, and Microcrystalline Guanine in Single Aurantiochytrium limacinumCells with Linear and Nonlinear Raman Microspectroscopy

Author

Sasaki, Risa, Toda, Shogo, Sakamoto, Takaiku, Sakuradani, Eiji, and Shigeto, Shinsuke

Abstract

Thraustochytrids are heterotrophic marine protists known for their high production capacity of various compounds with health benefits, such as polyunsaturated fatty acids and carotenoids. Although much effort has been focused on developing optimal cultivation methods for efficient microbial production, these high-value compounds and their interrelationships are not well understood at the single-cell level. Here we used spontaneous (linear) Raman and multiplex coherent anti-Stokes Raman scattering (CARS) microspectroscopy to visualize and characterize lipids (e.g., docosahexaenoic acid) and carotenoids (e.g., astaxanthin) accumulated in single living Aurantiochytrium limacinumcells. Spontaneous Raman imaging with the help of multivariate curve resolution–alternating least-squares enabled us to make unambiguous assignments of the molecular components we detected and derive their intracellular distributions separately. Near-IR excited CARS imaging yielded the Raman images at least an order of magnitude faster than spontaneous Raman imaging, with suppressed contributions of carotenoids. As the culture time increased from 2 to 5 days, the lipid amount increased by a factor of ∼7, whereas the carotenoid amount did not change significantly. Furthermore, we observed a highly localized component in A. limacinumcells. This component was found to be mixed crystals of guanine and other purine derivatives. The present study demonstrates the potential of the linear–nonlinear Raman hybrid approach that allows for accurate molecular identification and fast imaging in a label-free manner to link information derived from single cells with strategies for mass culture of useful thraustochytrids.

Published
2023
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19. Isolation and characterization of indigo-reducing bacteria and analysis of microbiota from indigo fermentation suspensions

Author

Nakagawa, Kasumi, Takeuchi, Michiki, Tada, Manami, Matsunaga, Momoka, Kugo, Masami, Kiyofuji, Suzuna, Kikuchi, Mayu, Yomota, Kazuya, Sakamoto, Takaiku, Kano, Kenji, Ogawa, Jun, and Sakuradani, Eiji

Abstract

In natural indigo dyeing, the water-insoluble indigo included in the composted indigo leaves called sukumois converted to water-soluble leuco-indigo through the reduction activities of microorganisms under alkaline conditions. To understand the relationship between indigo reduction and microorganisms in indigo-fermentation suspensions, we isolated and identified the microorganisms that reduce indigo and analyzed the microbiota in indigo-fermentation suspensions. Indigo-reducing microorganisms, which were not isolated by means of a conventional indigo carmine-reduction assay method, were isolated by using indigo as a direct substrate and further identified and characterized. We succeeded in isolating bacteria closely related to Corynebacterium glutamicum, Chryseomicrobium aureum, and Enterococcussp. for the first time. Anthraquinone was found to be an effective mediator that facilitated the indigo-reduction activity of the isolated strains. On analysis of the microbiota in indigo-fermentation suspensions, the ratio of indigo-reducing bacteria and others was found to be important for maintaining the indigo-reduction activity.Graphical AbstractThe new indigo-reducing bacteria were isolated by the novel method from the indigo fermentation suspensions. The dyeing activities were explained by the analysis of microbiota.

Published
2022
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27. Changes in the Gene Expression of the White Rot Fungus Phanerochaete chrysosporium Due to the Addition of Atropine.

Author

Minami, Masahiko, Suzuki, Kazumi, Shimizu, Akifumi, Hongo, Tomohiro, Sakamoto, Takaiku, Ohyama, Naoki, Kitaura, Hironori, Kusaka, Akiho, Iwama, Kenji, and Irie, Toshikazu

Subjects
GENE expression, PHANEROCHAETE, ATROPINE, BIOMARKERS, GENES, LIGNIN biodegradation
Abstract

The article presents a study on the changes in gene expression of fungus phanerochaete chrysosporium due to atropine. It states that a long serial analysis of gene expression library from a 3-d culture of fungus with atropine which contains tags was constructed. Also, 2-d cultures in which the fungus has not yet produced ligninolytic enzymes were also analyzed. It was found that of the 595 genes, 164 showed expression patterns, in which many of those 164 genes involved in lignin degradation.

Published
2009
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30. The white-rot fungus pleurotus ostreatus transformant overproduced intracellular cAMP and laccase.

Author

Yao Y, Sakamoto T, Honda Y, Kagotani Y, Izumitsu K, Suzuki K, and Irie T

Subjects
Copper Sulfate pharmacology, Coumaric Acids pharmacology, Culture Media, Fungal Proteins metabolism, GTP-Binding Protein alpha Subunits metabolism, Laccase biosynthesis, Mutation, Pleurotus drug effects, Pleurotus enzymology, Transformation, Genetic, Transgenes, Cyclic AMP biosynthesis, Fungal Proteins genetics, GTP-Binding Protein alpha Subunits genetics, Gene Expression Regulation, Fungal, Laccase genetics, Pleurotus genetics
Abstract

Transformation of Pleurotus ostreatus PC9 with the mutated heterotrimeric G protein alpha subunit (Gα) gene resulted in higher laccase (Lac) activity and intracellular cyclic adenosine monophosphate (cAMP) concentrations as compared to those in wild-type PC9. The transformant also exhibited higher Lac activity than the wild type when cultured in a medium containing known Lac inducers CuSO4 and ferulic acid.

Published
2013
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