MICROBIOLOGICAL CHARACTERISTICS OF SOME BACTERIAL AGENTS ISOLATED FROM RAINBOW TROUT FARMS

ADVANCES IN AQUACULTURE AND FISHERIES RESEARCH, Prof. Dr. Aysun KOP,Dr. Öğr. Üyesi Boran KARATAŞ, Editör, İksad Yayınevi, Ankara, ss.39-58, 2022

The most common bacterial diseases in our country are Yersinia ruckeri,

Lactococcus garvieae, Vibrio salmonicida, Aeromonas hydrophila, Listonella

anguillarum, Pseudomonas picicida, Flavobacterium psychophilium,

Renibacterium salmoninarium in freshwater fish. In marine fish; Listonella

anguillarum (Vibriosis), Photobacterium damsela subsp. Piscidia

(Pasteurellosis), Tenacibaculum maritimum (Myxobacteriosis), Streptococcus

iniae, Lactococcus garvieae, Streptococcus uberis (Streptococcosis,

Lactococcosis), Aeromonas hydrophila (Motile Aeromonas Septicaemia) and

Pseudomonas anguilliseptica (Winter diseases) (Timur and Timur, 1985).

If we look at the general structure of bacteria; they have a "prokaryotic"

cell structure because they do not have nuclei and membrane-enclosed

organelles. Molecules such as chlorophyll and oxygenated respiratory enzymes

are found on the folds extending from the cell membrane to the cytoplasm or

free in the cytoplasm

All bacterial cells contain membrane, wall, ribosome, DNA, RNA and

various enzyme systems. In some species, in addition to these structures, there

may be some specialised functions. Cilia and flagella, which extend outward

from the cell membrane, provide movement and protection. In very few species,

there is a third cell covering. This structure, called capsule, increases the

resistance to unfavourable conditions. For this reason, encapsulated bacteria are

usually pathogenic (disease-causing). The cell wall in bacteria is made of

protein, fat and carbohydrate and does not contain cellulose. It shapes and

protects the bacteria