Rosalina Stancheva, Sydney Brown, Gregory L. Boyer, Bofan Wei, Ramesh Goel, Simone Henry, Nathaniel V. Kristan, Betsy Read
{"title":"盐度胁迫和氮耗竭对淡水蓝藻微oleus anatoxicus Stancheva & Conklin 的生长、形态和毒素产生的影响","authors":"Rosalina Stancheva, Sydney Brown, Gregory L. Boyer, Bofan Wei, Ramesh Goel, Simone Henry, Nathaniel V. Kristan, Betsy Read","doi":"10.1007/s10750-024-05586-3","DOIUrl":null,"url":null,"abstract":"<p>Cyanobacterium <i>Microcoleus anatoxicus,</i> isolated from a coastal stream in northern California, produces both anatoxin-a (ATX) and dihydroanatoxin-a (dhATX), responsible for dog deaths, but its environmental preferences are unknown. We tested the effect of environmentally relevant stressors, e.g., salinity enrichment and nitrogen (N) depletion, on mat formation and toxicity of <i>M. anatoxicus</i> during the stationary growth phase in culture. <i>Microcoleus anatoxicus</i> showed broad salinity tolerance and the potential to enter estuaries and produce toxins in mesohaline conditions. Maximum growth was observed in oligohaline waters with salinity of 4.6 ppt. Moderate salinity stress (up to 7.8 ppt) did not affect dhATX production significantly. In contrast, higher salinity above 9.3 ppt had a detrimental effect on cell growth and significantly suppressed dhATX production. Formation of a common polysaccharide sheath covering multiple filaments was characteristic with increased salinity and may provide protection against osmotic stress. <i>Microcoleus anatoxicus</i> grown for 40 days in N-depleted medium formed mats with significantly elevated dhATX and increased ATX concentrations. Phycobilisome degradation was a possible acclimation response to N-limitation, as indicated by distinctly keritomized and pale cells in these cultures. In both experiments, most of the anatoxins were extracellular, probably due to toxin leaking during the stationary growth phase.</p>","PeriodicalId":13147,"journal":{"name":"Hydrobiologia","volume":"22 1","pages":""},"PeriodicalIF":2.2000,"publicationDate":"2024-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Effect of salinity stress and nitrogen depletion on growth, morphology and toxin production of freshwater cyanobacterium Microcoleus anatoxicus Stancheva & Conklin\",\"authors\":\"Rosalina Stancheva, Sydney Brown, Gregory L. Boyer, Bofan Wei, Ramesh Goel, Simone Henry, Nathaniel V. Kristan, Betsy Read\",\"doi\":\"10.1007/s10750-024-05586-3\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>Cyanobacterium <i>Microcoleus anatoxicus,</i> isolated from a coastal stream in northern California, produces both anatoxin-a (ATX) and dihydroanatoxin-a (dhATX), responsible for dog deaths, but its environmental preferences are unknown. We tested the effect of environmentally relevant stressors, e.g., salinity enrichment and nitrogen (N) depletion, on mat formation and toxicity of <i>M. anatoxicus</i> during the stationary growth phase in culture. <i>Microcoleus anatoxicus</i> showed broad salinity tolerance and the potential to enter estuaries and produce toxins in mesohaline conditions. Maximum growth was observed in oligohaline waters with salinity of 4.6 ppt. Moderate salinity stress (up to 7.8 ppt) did not affect dhATX production significantly. In contrast, higher salinity above 9.3 ppt had a detrimental effect on cell growth and significantly suppressed dhATX production. Formation of a common polysaccharide sheath covering multiple filaments was characteristic with increased salinity and may provide protection against osmotic stress. <i>Microcoleus anatoxicus</i> grown for 40 days in N-depleted medium formed mats with significantly elevated dhATX and increased ATX concentrations. Phycobilisome degradation was a possible acclimation response to N-limitation, as indicated by distinctly keritomized and pale cells in these cultures. In both experiments, most of the anatoxins were extracellular, probably due to toxin leaking during the stationary growth phase.</p>\",\"PeriodicalId\":13147,\"journal\":{\"name\":\"Hydrobiologia\",\"volume\":\"22 1\",\"pages\":\"\"},\"PeriodicalIF\":2.2000,\"publicationDate\":\"2024-06-18\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Hydrobiologia\",\"FirstCategoryId\":\"99\",\"ListUrlMain\":\"https://doi.org/10.1007/s10750-024-05586-3\",\"RegionNum\":3,\"RegionCategory\":\"生物学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"MARINE & FRESHWATER BIOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Hydrobiologia","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1007/s10750-024-05586-3","RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MARINE & FRESHWATER BIOLOGY","Score":null,"Total":0}
Effect of salinity stress and nitrogen depletion on growth, morphology and toxin production of freshwater cyanobacterium Microcoleus anatoxicus Stancheva & Conklin
Cyanobacterium Microcoleus anatoxicus, isolated from a coastal stream in northern California, produces both anatoxin-a (ATX) and dihydroanatoxin-a (dhATX), responsible for dog deaths, but its environmental preferences are unknown. We tested the effect of environmentally relevant stressors, e.g., salinity enrichment and nitrogen (N) depletion, on mat formation and toxicity of M. anatoxicus during the stationary growth phase in culture. Microcoleus anatoxicus showed broad salinity tolerance and the potential to enter estuaries and produce toxins in mesohaline conditions. Maximum growth was observed in oligohaline waters with salinity of 4.6 ppt. Moderate salinity stress (up to 7.8 ppt) did not affect dhATX production significantly. In contrast, higher salinity above 9.3 ppt had a detrimental effect on cell growth and significantly suppressed dhATX production. Formation of a common polysaccharide sheath covering multiple filaments was characteristic with increased salinity and may provide protection against osmotic stress. Microcoleus anatoxicus grown for 40 days in N-depleted medium formed mats with significantly elevated dhATX and increased ATX concentrations. Phycobilisome degradation was a possible acclimation response to N-limitation, as indicated by distinctly keritomized and pale cells in these cultures. In both experiments, most of the anatoxins were extracellular, probably due to toxin leaking during the stationary growth phase.
期刊介绍:
Hydrobiologia publishes original research, reviews and opinions regarding the biology of all aquatic environments, including the impact of human activities. We welcome molecular-, organism-, community- and ecosystem-level studies in contributions dealing with limnology and oceanography, including systematics and aquatic ecology. Hypothesis-driven experimental research is preferred, but also theoretical papers or articles with large descriptive content will be considered, provided they are made relevant to a broad hydrobiological audience. Applied aspects will be considered if firmly embedded in an ecological context.