In recent years,red tides occurred frequently in coastal areas worldwide.Various methods based on the use of clay,copper sulfate,and bacteria have been successful in controlling red tides to some extent.As a new defen...In recent years,red tides occurred frequently in coastal areas worldwide.Various methods based on the use of clay,copper sulfate,and bacteria have been successful in controlling red tides to some extent.As a new defensive agent,marine microorganisms are important sources of compounds with potent inhibitory bioactivities against red-tide microalgae,such as Gymnodinium sp.(Pyrrophyta).In this study,we isolated a marine bacterium,HSB07,from seawater collected from Hongsha Bay,Sanya,South China Sea.Based on its 16S rRNA gene sequence and biochemical characteristics,the isolated strain HSB07 was identified as a member of the genus Halomonas.A crude ethyl acetate extract of strain HSB07 showed moderate inhibition activity against Gymnodinium sp.in a bioactive prescreening experiment.The extract was further separated into fractions A,B,and C by silica gel column chromatography.Fractions B and C showed strong inhibition activities against Gymnodinium.This is the first report of inhibitory activity of secondary metabolites of a Halomonas bacterium against a red-tide-causing microalga.展开更多
Abstract With the global ban on the application of organotin-based marine coatings by the International Maritime Organization, the development of environmentally friendly, low-toxic and nontoxic antifouling compounds ...Abstract With the global ban on the application of organotin-based marine coatings by the International Maritime Organization, the development of environmentally friendly, low-toxic and nontoxic antifouling compounds for marine industries has become an urgent need. Marine microorganisms have been considered as a potential source of natural antifoulants. In this study, the antifouling potential of marine dinoflagellate Amphidinium carterae, the toxic and red-tide microalgae, was investigated. We performed a series of operations to extract the bioactive substances from Amphidinium carterae and tested their antialgal and antilarval activities. The crude extract of Amphidinium carterae showed significant antialgal activity and the ECs0 value against Skeletonema costatum was 55.4 ~tg mL-1. After purification, the isolated bioactive substances （the organic extract C） exhibited much higher antialgal and antilar- val activities with ECso of 12.9μgmL-1 against Skeletonema costatum and LC50 of 15.1 μmL-1 against Amphibalanus amphitrite larvae. Subsequently, IR, Q-TOFMS, and GC-MS were utilized for the structural elucidation of the bioactive compounds, and a series of unsaturated and saturated 16- to 22-carbon fatty acids were detected. The data suggested the bioactive compounds isolated from Amphidinium carterae exhibited a significant inhibiting effect against the diatom Skeletonema costatum and Amphibalanus amphi- trite larvae, and could be substitutes for persistent, toxic antifouling compounds.展开更多
基金Supported by the Science & Technology Project of Nantong(No.AS2011012)the National Key Technology Research and Development Program(No.2011BAE06B04-05)the Open Project Program of the Key Laboratory of Marine Bio-resources Sustainable Utilization,SCSIO,CAS(No.LMB121006)
文摘In recent years,red tides occurred frequently in coastal areas worldwide.Various methods based on the use of clay,copper sulfate,and bacteria have been successful in controlling red tides to some extent.As a new defensive agent,marine microorganisms are important sources of compounds with potent inhibitory bioactivities against red-tide microalgae,such as Gymnodinium sp.(Pyrrophyta).In this study,we isolated a marine bacterium,HSB07,from seawater collected from Hongsha Bay,Sanya,South China Sea.Based on its 16S rRNA gene sequence and biochemical characteristics,the isolated strain HSB07 was identified as a member of the genus Halomonas.A crude ethyl acetate extract of strain HSB07 showed moderate inhibition activity against Gymnodinium sp.in a bioactive prescreening experiment.The extract was further separated into fractions A,B,and C by silica gel column chromatography.Fractions B and C showed strong inhibition activities against Gymnodinium.This is the first report of inhibitory activity of secondary metabolites of a Halomonas bacterium against a red-tide-causing microalga.
基金supported by the Natural Science Foundation of China under Grant No.41376106the Natural Science Foundation of Shandong province under Grant No.ZR2013DM017
文摘Abstract With the global ban on the application of organotin-based marine coatings by the International Maritime Organization, the development of environmentally friendly, low-toxic and nontoxic antifouling compounds for marine industries has become an urgent need. Marine microorganisms have been considered as a potential source of natural antifoulants. In this study, the antifouling potential of marine dinoflagellate Amphidinium carterae, the toxic and red-tide microalgae, was investigated. We performed a series of operations to extract the bioactive substances from Amphidinium carterae and tested their antialgal and antilarval activities. The crude extract of Amphidinium carterae showed significant antialgal activity and the ECs0 value against Skeletonema costatum was 55.4 ~tg mL-1. After purification, the isolated bioactive substances （the organic extract C） exhibited much higher antialgal and antilar- val activities with ECso of 12.9μgmL-1 against Skeletonema costatum and LC50 of 15.1 μmL-1 against Amphibalanus amphitrite larvae. Subsequently, IR, Q-TOFMS, and GC-MS were utilized for the structural elucidation of the bioactive compounds, and a series of unsaturated and saturated 16- to 22-carbon fatty acids were detected. The data suggested the bioactive compounds isolated from Amphidinium carterae exhibited a significant inhibiting effect against the diatom Skeletonema costatum and Amphibalanus amphi- trite larvae, and could be substitutes for persistent, toxic antifouling compounds.
