Effects of natural polymer (Poly-β-hydroxybutyrate) and its degrading bacteria on lipid metabolism and digestive tract pH in Siberian Sturgeon Acipenser baerii Brandt, 1869 fingerlings

Five hundred and ninety two Siberian sturgeon (A. baerii) fingerlings (average weight, 11.1±0.9 g) were randomly distributed in 16 tanks (150 L) at a density of 35 fish per tank and fed different treatments (Control, degrading bacteria, 2% PHB, degrading bacteria 2%PHB) for 60 days. At the end of the experiment, the results indicated that the fish fed PHB or bacteria treatments had low midgut pH and the lowest pH was observed in PHB treatment. Also PHB significantly decreased hindgut pH then the others and the lowest hindgut pH was seen in PHB treatment (p