title: [Regulation of symbiotic interactions in algobacterial associations].
abstract: OBJECTIVE
  To study mechanisms of survival and regulation of natural algobacterial associations.
  
  
  METHODS
  Lysozyme, antilysozyme, catalase and antagonistic activity as well as hydrogen peroxide production were determined in algobacterial associations formed by green algae or cyanobacteria and satellite bacteria. For assessment of reactions of microbial interactions, derivates of Escherichia coli, which differ on the presence of antilysozyme and catalase signs, were used.
  
  
  RESULTS
  Multidirectional effects of symbionts in biocenosis were revealed. Involvement of functional systems lysozyme-antilysozyme and hydrogen peroxide-catalase in regulation of associative interactions in algae-bacterial biocenosis was established. In conditions of antibacterial action of algae's hydrogen peroxide, catalase activity of associate bacteria provides survival of microorganisms in association with algae, whereas high level of catalase activity promotes domination of associate bacteria in algobacterial communities. Antagonistic activity allows the microalgae to suppress growth of undesirable microorganisms and regulate their number in algobacterial cenosis.
  
  
  CONCLUSIONS
  Functional systems lysozyme-antilysozyme, hydrogen peroxide-catalase as well as antagonistic activity of symbionts form the basis for regulation of symbiotic interactions in associations of water microorganisms, which has ecological and sanitary-hygienic implications.
authors.forename: N V
authors.initials: NV
authors.lastname: Nemtseva
authors.forename: M E
authors.initials: ME
authors.lastname: Ignatenko
authors.forename: E A
authors.initials: EA
authors.lastname: Selivanova
authors.forename: O A
authors.initials: OA
authors.lastname: Gogoleva
authors.forename: T N
authors.initials: TN
authors.lastname: Iatsenko-Stepanova
authors.forename: A O
authors.initials: AO
authors.lastname: Plotnikov
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D002374:Catalase / Q000378:metabolism; D000460:Chlorophyta / Q000201:enzymology / Q000382:microbiology / Q000502:physiology*; D006861:Hydrogen Peroxide / Q000378:metabolism; D009113:Muramidase / Q000037:antagonists & inhibitors / Q000378:metabolism; D013559:Symbiosis
chemical_list: D006861:Hydrogen Peroxide; D002374:Catalase; D009113:Muramidase