Bibliometric analysis of domestic symbiotic and epibiotic marine microorganisms based on CNKI database

The application of overgrowth microorganisms in ocean research was discussed,using the China National Knowledge Infrastructure(CNKI)network database to retrieve papers on the topic of symbiotic microbes(=198)and symbiotic marine microorganisms(n=94).Bibliometric Analysis are conducted in terms of the published trends,subject headings and other aspects.The output of literature in this field has increased rapidly in the past15years.57.4%of the papers were published in the last five years.And the relevance of research topics has increased in recent years.The current research focuses on community diversity,secondary metabolites,biological activities and antibacterial activities.Literature analysis is helpful to understand the overall development trend of overgrowth microorganisms in ocean research.

New Records of Marine Diatoms for the American Continent Found on Stone Scorpionfish Scorpaena mystes

The survey of new benthic substrata is expected to yield new records of diatom taxa. A particular type of substratum is the skin of the Stone scorpionfish Scorpaena mystes Jordan & Starks, 1895 that, because of its benthic form of life, represents a potential colonizing surface for various organisms, including epizoic and opportunistic diatom taxa (epibiotic community). Thus, a floristic survey of diatoms was carried out by sampling the epibiotic community from S. mystes specimens collected in the east coast of Baja California Sur (Gulf of California). Thirty diatoms are new records for Mexican littorals. Twelve of these taxa had not been hitherto recorded for American coasts. Micrographs, and morphometric and distribution data on these taxa are provided.

Antibacterial and bioiflm inhibitory activities of bacteria associated with polychaetes

Objective:To study the antibacterial and antibiofilm activities expressed by epibiotic bacteria associated with the polychaetes Platynereis dumerilii and Syllis sp.Methods:A total of 32 cultivable bacterial strains were isolated from the two polychaete species.The crude extracts were tested for antibacterial activity and biofilm inhibitory activity against pathogenic and biofilm-forming bacterial strains.Extracts of the strains which showed strong activity were analyzed by thin-layer chromatography(TLC)and the bacterial strains were identified based on 16S rRNA gene sequencing.Results:Extracts of 13 bacterial strains showed inhibitory activity against pathogenic and biofilm-forming bacteria.The crude extracts also affected the synthesis of extracellular polymeric substances and cell surface hydrophobicity of the Alteromonas sp.isolated from marine biofilm.The adhesion of Alteromonas sp.on glass surface showed significant variation between surface-associated bacterial crude extract treatment and control groups.Among the 13 bacteria,two strains PA8 and PA19 were further analyzed for bioactive fractions.Thinlayer chromatography indicated the presence of a single active fraction in the crude extract of both the bacterial strains.The epibiotic bacterial strains P8 and P19 were identified as Exiguobacterium sp.and Actinobacterium sp.respectively based on 16S rRNA gene sequencing.Conclusions:The present study indicates that bacteria associated with marine invertebrates inhabiting the coastal waters could be used as a potential source for the isolation of bioactive metabolites.