Pest management science · 2026
UV mutagenesis-enhanced Streptomyces nogalater produces a novel streptothricin-like compound with strong activity against cabbage soft rot.
СтатьяНазвание и аннотация: Перевод пока не подготовлен
Обработка статьи · этапы, ошибки и управление
Загрузка состояния…
Ошибки и ограничения
История · было → стало
Состояние обновляется каждые 5 секунд, пока блок открыт. Процент показывается только там, где известен объём работы. Пауза останавливает продолжение этапа; текущий запрос к источнику может завершиться.
Kim Young Sook, Umurzokov Mirjalol, Kim Hae Young, Jin Chun-Zhi, Kim Eun Ae, Cho Kwang Min
Аннотация
BACKGROUND: A total of 1000 soil-derived actinomycetes were isolated and screened for antibacterial activity against Pectobacterium carotovorum subsp. carotovorum (cabbage soft-rot disease). The most potent isolate, KRA705-18, was selected and UV mutagenesis was performed to improve its bioactivity. The active compound was purified, and its molecular formula and structure were identified through multiple spectroscopic analysis.
RESULTS: An irradiation time of 90 s was found to be optimal for mutant selection, yielding a 1.09% survival rate. After two successive mutagenesis cycles, the mutant strain (Streptomyces sp. KRA0514-6) exhibited the strongest and most stable antibacterial activity, consistently achieving over 90% inhibition within 24 h. The culture broth of the mutant achieved complete (100%) cabbage soft rot control at a 250-fold dilution, comparable to oxolinic acid (200 ppm) under glasshouse conditions. Field trials further showed stable activity at the same dilution rates, with control efficacies of more than 70% at 21 days after treatment. Phylogenetic analysis based on 16S rRNA gene sequencing identified the mutant strain as Streptomyces sp. KRA0514-6, closely related to Streptomyces nogalater JCM4799T. Bioassay-guided fractionation and purification of culture filtrate using C18 open-column chromatography, Sephadex LH-20, preparative high-performance liquid chromatography and hydrophilic interaction liquid chromatography led to the isolation of the active substance HL-3. In vivo glasshouse assays confirmed that purified HL-3 provided 100% cabbage soft rot disease control at concentrations >1 ppm. HR-ESI-MS analysis determined the molecular weight of HL-3 to be 459 g mol-1, leading to the identification of its molecular formula as C17H29N7O8. Finally, by nuclear magnetic resonance spectroscopic analysis, HL-3 was identified as novel streptothricin-like compound containing N-methylglycine instead of β-lysine.
CONCLUSION: Overall, UV mutagenesis effectively enhanced the antibacterial potential of the wild strain, and the purified compound, HL-3, exhibited potent activity against cabbage soft rot disease, which can be a promising biocontrol agent for sustainable plant disease management strategies. The results of this study provide new insights into streptothricin structure-activity relationships and suggest the existence of unknown biosynthetic mechanisms of S. nogalater. © 2026 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
RESULTS: An irradiation time of 90 s was found to be optimal for mutant selection, yielding a 1.09% survival rate. After two successive mutagenesis cycles, the mutant strain (Streptomyces sp. KRA0514-6) exhibited the strongest and most stable antibacterial activity, consistently achieving over 90% inhibition within 24 h. The culture broth of the mutant achieved complete (100%) cabbage soft rot control at a 250-fold dilution, comparable to oxolinic acid (200 ppm) under glasshouse conditions. Field trials further showed stable activity at the same dilution rates, with control efficacies of more than 70% at 21 days after treatment. Phylogenetic analysis based on 16S rRNA gene sequencing identified the mutant strain as Streptomyces sp. KRA0514-6, closely related to Streptomyces nogalater JCM4799T. Bioassay-guided fractionation and purification of culture filtrate using C18 open-column chromatography, Sephadex LH-20, preparative high-performance liquid chromatography and hydrophilic interaction liquid chromatography led to the isolation of the active substance HL-3. In vivo glasshouse assays confirmed that purified HL-3 provided 100% cabbage soft rot disease control at concentrations >1 ppm. HR-ESI-MS analysis determined the molecular weight of HL-3 to be 459 g mol-1, leading to the identification of its molecular formula as C17H29N7O8. Finally, by nuclear magnetic resonance spectroscopic analysis, HL-3 was identified as novel streptothricin-like compound containing N-methylglycine instead of β-lysine.
CONCLUSION: Overall, UV mutagenesis effectively enhanced the antibacterial potential of the wild strain, and the purified compound, HL-3, exhibited potent activity against cabbage soft rot disease, which can be a promising biocontrol agent for sustainable plant disease management strategies. The results of this study provide new insights into streptothricin structure-activity relationships and suggest the existence of unknown biosynthetic mechanisms of S. nogalater. © 2026 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.