Lysis of Antarctic algal strains by bacterial pathogen.
The present paper describes the isolation, physiological and genetic characteristic of a bacterial agent which inhibits the growth of algae and causes death of laboratory cultures of Antarctic microalgal strains: prokaryotic cyanobacteria Synechocystis salina and green eukaryotic microalga Choricistis minor. The bacterial strain LB1 was isolated from algal damaged laboratory cultures of S. salina. It was established that this bacterium is obligate aerobic, Gram-positive, non-spore-forming, immotile, irregular rods with dimensions 0.3-2 μm. Our results showed that LB1 has algicidal effect to S. salina as well as to C. minor. Transmission electron microscopy observations confirmed the destruction of S. salina by the bacterium. Biochemical analysis of LB1 revealed positive reaction to D-glucose, catalase, hydrolysis of gelatin, acid production from: lactose, L-arabinose, L-ramnose, esculin and β-galactosidase. The partial sequence (1,404 bp) of the 16S rRNA gene of LB1 showed 99 % similarity with type strains of the genus Microbacterium. The results of the biochemical, antimicrobial and of 16S rRNA analysis of LB1 allowed us to identify LB1 as Microbacterium sp. Studying expression of pathogenicity of the bacteria to algal cultures will help to solve the problem of algal production for biotechnological purposes.
Department of Experimental Algology, Institute of Plant Physiology and Genetics, Bulgarian Academy of Sciences, 21 Acad. G. Bonchev Str., 1113, Sofia, Bulgaria, juivanova@yahoo.com.
Juliana
J
Ivanova
Galina
G
Stoyancheva
Irina
I
Pouneva
D000192:Actinomycetales / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D000864:Antarctic Regions; D015373:Bacterial Typing Techniques; D001433:Bacteriolysis; D000460:Chlorophyta / Q000502:physiology*; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D046939:Synechocystis / Q000502:physiology*
D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S