research article: the effects of l-carnitine levels on population growth of rotifer brachionus plicatilis fed with chlorella vulgaris

In this study, s-type rotifer brachionus plicatilis were enriched with 10 levels (0, 0.001, 0.01, 0.1, 1, 10, 100, 500, 1000 and 1500 mg l-carnitine per l) of l-carnitine supplements dissolved in chlorella vulgaris culture medium in a 10 ml individual culture trial for 7 days. the initial rotifer density was 1 individual ml^-1. the trials were conducted to 200×0^6 cell ml^-1 at food density at 25±1ºc under an axenic condition in the laboratory. l-carnitine enrichment has shown considerable influence on the population growth of rotifer brachionus plicatilis. as a result, the maximum number of individuals was determined as 1560  10.00 rot./ml in the group enriched with 100 mg/l l-carnitine supplement and the lowest number of individuals was determined 376.6725.17 rot./ml in the group enriched with 1500 mg/l l-carnitine addition (p<0.05). the maximum growth rate was found to be 0.63±0.02 rot/ day in the group enriched with 100 mg/l l-carnitine addition (p<0.05). the maximum doubling time was 1.31±0.02 rot./ day for the group enriched with 1000 mg/l l-carnitine (p<0.05). the results suggested that l-carnitine could be a positive factor to enhance reproduction and population growth on enriched brachionus plicatilis under the optimum concentration.