title: [Isolation and identification of Marinobacter adhaerens HY-3 and its allelopathy on Skeletonema costatum].
abstract: The allelopathy between bacteria and algae is a very complicated physical and ecological phenomenon. A marine bacterium was isolated from the water of a shrimp and crab mix-culturing pond. By 16S rRNA analysis, it was identified as Marinobacter adhaerens HY-3. Skeletonema costatum, a common dominant species of red-tide microorganism in China, was chosen as the other research object. The allelopathic effect of Marinobacter adhaerens HY- 3 on S. costatum was studied. Using the growth mass of Skeletonema costatum and the content of chlorophyll a as the parameters, the effects of HY-3 on the growth and photosynthesis of Skeletonema costatum were studied after co-cultivation and addition of extracellular metabolites of HY-3. The results showed that the growth of S. costatum was inhibited when the concentration of the strain HY-3 was above 10(4), and the growth mass of the 10(4), 10(6) and 10(8) HY-3 group was 70%, 23% and 22% of the control group respectively on the 10th day, with the content of chlorophyll being 88%, 62% and 60% of the control group, respectively. Therefore, the suppression increased with increasing concentration of HY-3. However, addition of extracellular metabolites of HY-3 had no effect on the growth of S. costatum.
  
  
  CONCLUSIONS
  M. adhaerens HY-3 had certain allelopathy on S. costatum and affected its growth and photosynthesis. Moreover, interaction between M. adhaerens HY-3 and S. costatum was achieved by their direct contact and the extracellular metabolites did not contain allelopathy factors.
authors.affiliation: School of Environment Science and Spatial Informatics, China University of Mining and Technology, Xuzhou 221008, China. whbvirus@126.com
authors.forename: Hong-Bin
authors.initials: HB
authors.lastname: Wang
authors.forename: Wen-Hui
authors.initials: WH
authors.lastname: Chen
authors.forename: Xin-Shu
authors.initials: XS
authors.lastname: Li
authors.forename: Shi-Hu
authors.initials: SH
authors.lastname: Li
authors.forename: Bin-Lun
authors.initials: BL
authors.lastname: Yan
mesh_terms: D064089:Allelopathy; D017377:Diatoms / Q000254:growth & development* / Q000502:physiology*; D005068:Eutrophication; D008386:Marine Biology; D053520:Marinobacter / Q000302:isolation & purification* / Q000502:physiology*