Dietary supplementation of Geotrichum candidum improves growth, gut microbiota, immune-related gene expression and disease resistance in gibel carp CAS III (Carassius auratus gibelio)

摘要

Geotrichum candidum is a filamentous fungus mostly used in the dairy industry for cheese ripening and flavoring. The current study was designed to evaluate the potential probiotics effect of dietary supplementation of G. candidum on growth, digestive enzymes activities, gut microbiota and immune-related gene expression and disease resistance in Gibel carp CAS III (Carassius auratus gibelio) against A. hydrophila infections. For this purpose, 420 healthy fish (initial body weight: 7.09 +/- 0.02g) were randomly divided into 7 feeding groups in triplicates of 20 fish in each tank. Seven isocaloric and isonitrogenous diets were prepared, supplemented with 6 different doses of G. candidum viz; C: 0, T1:10(6), T2:10(7), T3:10(8), T4:10(9), T5:10(10), T6:10(11) CFU/kg diet and fed to fish twice a day for 60 days. Results showed significantly higher weight gain (WG) and feed efficiency (FE) in groups fed 10(6) and 10(8) CFU/kg diet compared to the control (P < 0.05).