Exploring the application of Corynebacterium glutamicum single cell protein in the diet of flathead grey mullet (Mugil cephalus): effects on growth performance, digestive enzymes activity and gut microbiota

The capacity of utilising a single cell protein (SCP) ingredient coming from Corynebacterium glutamicum was assessed on adult grey mullet ( Mugil cephalus ) reared in captive conditions. experiment carried out using triplicate groups 68 g average initial body weight. Three diets, SCP0, SCP10 and SCP20 with increasing inclusion SCP (0%, 10% 20%) substitution soybean, poultry fish meal were formulated to contain 30% protein, fat 18.5 Mj/kg feed digestible energy. After 113 days, fed diets presented significantly lower growth performance significant activity the alkaline proteases aminopeptidases compared diet without inclusion. Gut microbiota appeared modulated by being dominated at phylum level Fusobacteria SCP0 (51.1%), while (67.3%) (53.2%) Proteobacteria dominant. Data evinces deficiency utilisation as cause poor diets. A hypothesis has been proposed that an incomplete cell-wall lysis accounts for this outcome because particular organisation digestive system (which lack acidic stomach digestion) failing development functional gizzard (no access sand conditions). Even though outcomes research quite unexpected, they will improve our knowledge flathead provide some theoretical basis improved low FM SBM aquafeed species.