Auxin production of the filamentous cyanobacterial Planktothricoides strain isolated from a polluted river in Vietnam. (December 2021)

• Record Type: Journal Article
• Authors: Duong, Thi Thuy; Nguyen, Thi Thu Lien; Dinh, Thi Hai Van; Hoang, Thi Quynh; Vu, Thi Nguyet; Doan, Thi Oanh; Dang, Thi Mai Anh; Le, Thi Phuong Quynh; Tran, Dang Thuan; Le, Van Nhan; Nguyen, Quang Trung; Le, Phuong Thu; Nguyen, Trung Kien; Pham, Thi Dau; Bui, Ha Manh
• Is Part Of: Chemosphere. Volume 284(2021)
• Publication Date: 2021-12
• Subjects: Biofertilizer -- Cyanobacteria -- Indole-3-acetic acid -- Planktothricoides raciborskii -- Polluted river; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2021.131242
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Cyanobacteria are photosynthetic microorganisms with widespread diversity and extensive global distribution. They produce a wide variety of bioactive substances (e.g., lipopeptides, fatty acids, toxins, carotenoids, vitamins and plant growth regulators) that are released into culture media. In this study, the capability of a cyanobacterial strain of Planktothricoides raciborskii to produce intra- and extracellular auxins was investigated. The filamentous cyanobacterial P. raciborskii strain was isolated from a river in Vietnam, and it was cultivated in the laboratory under the optimum conditions of the BG11 culture medium and a pH of 7.0. The auxins were identified and quantified by the Salkowski colorimetric method and high-performance liquid chromatography coupled with mass spectrometry (HPLC–MS). Colorimetric analysis revealed that P. raciborskii produces extracellular indole-3-acetic acid (IAA) in the absence and presence of l -tryptophan. The maximum extracellular IAA concentration of the culture reached 118 ± 2 μg mL −1, which was supplemented with 900 μg mL −1 of l -tryptophan. HPLC–MS analysis revealed that the isolated cyanobacteria accumulate other plant-growth-promoting hormones besides IAA, such as indole-3-carboxylic acid (ICA), indole-3 butyric acid (IBA) and indole propionic acid (IPA). This is the first report on the production of auxins in an isolated strain of cyanobacteria Planktothricoides from a polluted river. The capability of producing auxins makes the P. raciborskii strain an appropriate candidate for the formulation of a biofertilizer. Graphical abstract: Image 1 Highlights: Planktothricoides raciborskii was isolated from a polluted river in Vietnam and cultured in BG 11 medium. Four Auxins (IBA, IPA, ICA, IAA) were found in the isolated P. raciborskii strain by HPLC-ESI-MS/MS analysis. Increased levels of IAA was observed in P. raciborskii strain under supplementation of l -tryptophan.