Fermentability of carbohydrates in anin vitrobatch culture method using inocula from Nile tilapia (Oreochromis niloticus) and European sea bass (Dicentrarchus labrax)

Abstract

This study investigated in vitro fermentability of wheatderived carbohydrates using inocula of Nile tilapia and European sea bass. Distal intestinal contents were incubated in bottles containing one of four fermentable substrates, i.e. glucose (GL), native wheat starch (WS), arabinoxylan (ABX) and whole wheat (WHT). Cumulative gas production was measured for 168 h. At the end of incubation, fermentation end-products were measured. A monophasic model was fitted to the gas production profiles of each bottle, thereby allowing calculation of gas kinetic parameters. Total gas production (mL g )1 organic matter) differed significantly between substrates for tilapia (GL: 268.9; WS: 388.0; ABX: 411.9; WHT: 413.2) and sea bass (GL: 338.6; WS: 189.3; ABX: 296.3; WHT: 264.0). Fermentation rates were highest for GL and lowest for WS, both for tilapia and sea bass. Fermentation of ABX and WHT yielded predominantly acetic and butyric acid, whereas GL and WS yielded also significant amounts of lactic acid. Ammonia (mL g )1 organic matter) was highest for WHT (tilapia: 80.36; sea bass: 70.39) and lowest for GL (tilapia: 46.01; sea bass: 32.83). In conclusion, intestinal microbes from Nile tilapia and European sea bass have the potential to ferment carbohydrates. Large differences exist in fermentability and composition of fermentation endproducts between carbohydrates. KEY WORDS

The autochthonous microbiota of the freshwater omnivores jundiá (Rhamdia quelen) and tilapia (Oreochromis niloticus) and the effect of dietary carbohydrates

“…Jundiá Rhamdia quelen (Quoy & Gaimard), an opportunistic omnivore, which has a varied diet that includes molluscs, crustaceans, fish, insects, detritus, algae and weeds (Castro & Casatti ; Kütter, de Azevedo Bemvenuti & Moresco ), has a short intestine and utilizes dietary carbohydrates less efficiently than other omnivores (Oliveira‐Filho & Fracalossi ; Moro, Camilo, Moraes & Fracalossi ; Rodrigues, Gominho‐Rosa, Cargnin‐Ferreira, de Francisco & Fracalossi ). However, tilapia Oreochromis niloticus L., a typical omnivore, which feeds predominantly on algae, plants and phytoplankton, has a long intestine and can tolerate and utilize higher levels of dietary carbohydrate (Leenhouwers, Pellikaan, Huizing, Coolen, Verreth & Schrama ). Absorption is enhanced by its long intestinal length and increased epithelial surface provided by the mucosal folds.…”

Fermentation of Arabinoxylan-Oligosaccharides, Oligofructose and their Monomeric Sugars by Hindgut Bacteria from Siberian Sturgeon and African Catfish in Batch Culture in vitro

“…In carp, however, certain carbohydrate substrates resulted in high amounts of propionic acid during an incubation period of 6 h [22]. Butyric acid production was relatively high using inocula from tilapia and seabass during incubation periods of up to 168 h [27]. In this study, the proportion of butyric and branched-chain fatty acids reached 28% in batches inoculated with Siberian sturgeon hindgut contents in the presence of fructose and OF at the end of the fermentation period (48 h) ( Table 1).…”

“…Fermentation of various carbohydrates using inocula of fish hindgut microbes has also been reported in common carp (Cyprinus carpio) [22], tilapia (Oreochromis niloticus) and European seabass (Dicentrarchus labrax) [27].…”

Progress and perspectives of short‐chain fatty acids in aquaculture

“…In vitro cultures of arabinoxylan, whole wheat, soybean‐oligosaccharides, isomalto‐oligosaccharides, raffinose, gentiobiose, lactosucrose, AXOS, oligofructose, xylose or fructose using inocula of fish gut microbes have yielded high production of major SCFAs in fish species such as common carp ( Cyprinus carpio ) (Kihara & Sakata ), Nile tilapia ( Oreochromis niloticus ) and European seabass ( Dicentrarchus labrax ) (Leenhouwers et al . ) and Siberian sturgeon and African catfish (Geraylou et al . ).…”