Role of bacteria with regard to chitin degradation in the digestive tract of the cod Gadus morhua
Danulat, E. (1986). Role of bacteria with regard to chitin degradation in the digestive tract of the cod Gadus morhua. Mar. Biol. (Berl.) 90(3): 335-343. https://dx.doi.org/10.1007/BF00428557
In: Marine Biology: International Journal on Life in Oceans and Coastal Waters. Springer: Heidelberg; Berlin. ISSN 0025-3162; e-ISSN 1432-1793, meer
|  |
| Trefwoorden |
Gadus morhua Linnaeus, 1758 [WoRMS]
Marien/Kust |
| Abstract |
Numbers of aerobic, heterotrophic and chitinolytic bacteria in stomach, pyloric caeca and intestine of eight specimens of freshly caught cod (Gadus morhua L.) were determined by the spread plate method (medium: sea water agar, including 1% chitin). In crude enzyme extracts, chitinase activity was assayed according to the end product measurement. Results revealed no correlation between the number of chitinoclasts and the level of chitinase activity in any part of the digestive tract of cod. In another series of studies, antibiotics (Ampicillin/Sisomicin, or Chloramphenicol) were applied via tank water and feed. In most cases, antibiotic treatment resulted in the complete elimination of bacteria from the digestive tract. In contrast, up to 1.0×109 chitinoclasts per g wet wt were determined in control fish. Chitinase did not reflect the absence or presence of bacteria: no significant difference in enzyme activities of cod treated with Ampicillin/Sisomicin and non-treated fish could be demonstrated. A decrease of chitinase activities of cod exposed to Chloramphenicol is interpreted as a toxic effect of this antibiotic on the fish. It is concluded that chitinase activities measured in the digestive tract of G. morhua primarily originate from fish tissues. |
|
