Biotechnological Investigation for the Prevention of Marine Biofouling II. Blue-Green Algae as Potential Producers of Biogenic Agents for the Growth Inhibition of Microfouling Organisms

1999 ◽  
Vol 42 (5) ◽  
Author(s):  
S. Abarzua ◽  
S. Jakubowski ◽  
S. Eckert ◽  
P. Fuchs
1997 ◽  
Vol 33 (4) ◽  
pp. 215-222 ◽  
Author(s):  
SATOSHI NAKAI ◽  
YUTAKA INOUE ◽  
MASAAKI HOSOMI ◽  
AKIHIKO MURAKAMI

1999 ◽  
Vol 39 (8) ◽  
pp. 47-53 ◽  
Author(s):  
Satoshi Nakai ◽  
Yutaka Inoue ◽  
Masaaki Hosomi ◽  
Akihiko Murakami

Inhibitory effects of macrophytes on the growth of blue-green algae (i.e. Microcystis aeruginosa, Anabaena flos-aquae, or Phormidium tenue) were evaluated in a coexistence culture system in which concentrations of different macrophyte species were varied (i.e. Egeria densa, Cabomba caroliniana, Myriophyllum spicatum, Ceratophyllum demersum, Eleocharis acicularis, Potamogeton oxyphyllus, Potamogeton crispus, Limnophila sessiliflora, or Vallisneria denseserrulata). Coexistence assay results showed that only the macrophytes C. caroliniana or M. spicatum inhibited the growth of all blue-green algae, with the inhibitory effects of M. spicatum being stronger than those of C. caroliniana and being produced by the release of allelopathic compounds. In subsequent initial addition assays using M. spicatum with the alga M. aeruginosa, no significant growth inhibition was observed; whereas, in contrast, quasi-continuous addition assays showed strong growth inhibition by M. spicatum. These results provide the first evidence that unstable, growth-inhibiting allelopathic compounds are continuously secreted by M. spicatum.


Author(s):  
L. V. Leak

Electron microscopic observations of freeze-fracture replicas of Anabaena cells obtained by the procedures described by Bullivant and Ames (J. Cell Biol., 1966) indicate that the frozen cells are fractured in many different planes. This fracturing or cleaving along various planes allows one to gain a three dimensional relation of the cellular components as a result of such a manipulation. When replicas that are obtained by the freeze-fracture method are observed in the electron microscope, cross fractures of the cell wall and membranes that comprise the photosynthetic lamellae are apparent as demonstrated in Figures 1 & 2.A large portion of the Anabaena cell is composed of undulating layers of cytoplasm that are bounded by unit membranes that comprise the photosynthetic membranes. The adjoining layers of cytoplasm are closely apposed to each other to form the photosynthetic lamellae. Occassionally the adjacent layers of cytoplasm are separated by an interspace that may vary in widths of up to several 100 mu to form intralamellar vesicles.


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