Enhancement of growth and intestinal flora in grass carp: The effect of exogenous cellulase

The draft genome of the grass carp (Ctenopharyngodon idellus) provides insights into its evolution and vegetarian adaptation

“…This analysis did not identify any genes encoding predicted cellulose-digesting enzymes in the gut, suggesting that the grass carp intestine may not digest and absorb cellulose, which reinforces the view that cellulase may be developed as an aquatic additive to promote the growth of grass carp 44 . However, sequencing of gut biota will likely prove to be more powerful in understanding how the grass carp digests plant materials.…”

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“…In our previous study with DORB, we found an increased utilization of DORB when the DORB was supplemented with exogenous enzymes in comparison to diet in which the enzyme was not supplemented in Labeo rohita diet (Ranjan et al, 2017). Zhou et al (2013) also found that cellulase supplemented duckweed based diet promoted the growth of grass carp. Present result is also supported by finding of Ai et al (2007), Yildrim and Turan (2010), Ghomi et al (2012) and Zamini et al (2014), who also reported positive effect of various commercial multi-enzyme complex (phytase, xylanase, β-glucanase, amylase, cellulase and pectinase) on the growth performance and feed efficiency of Lateolabrax japonicas, Clarias gariepinus, Huso huso and Salmo trutta, respectively.…”

“…are capable of disrupting plant cell wall integrity, consequently, this enhances rapid digestion by reducing viscosity in the gut (Zijlstra et al, 2010;Bedford & Cowieson, 2012). Apart from the potential of exogenous enzymes to enhance nutrient utilisation and growth (Adeola & Cowieson, 2011), they may alter substrates availability for specific populations of gut microbes, thus, altering bacterial community composition or activities (Bedford and Cowieson, 2012;Kiarie et al, 2013;Zhou et al, 2013;Jiang et al, 2014).…”

“…Similar observation were also made by many researchers for different species, Ng et al (1998) (1999) in Clarias gariepinus; Ng and Chen (2002) in Clarias macrocephalus × C. gariepinus., Kumar et al (2006) in Labeo rohita, Lin et al (2007) in Oreochromis niloticus × Oreochromis aureus; Zhou et al (2013) in Ctenopharyngodon idella. Increased endogenous enzyme activities lead to increased apparent nutrient digestibilities in Labeo rohita due to dietary exogenous enzyme, which is consistent with the findings of Ogunkoya et al (2006), who also found that exogenous enzyme supplementation to the soybean meal based diet improves the apparent digestibility coefficient of dry matter, protein, lipid and carbohydrate in Oncorhynchus mykiss.…”

Identification and characterization of Bacillus subtilis from grass carp (Ctenopharynodon idellus) for use as probiotic additives in aquatic feed

“…Cellulase is also frequently used in animal feeds to improve digestion, nutrient absorption and weight gain [45], especially for herbivorous fish, unable to produce cellulase endogenously to digest plant materials [46]. Additionally, previous studies suggested that cellulase could increase the amylase and protease activities and then promote the growth of fish [47], which is extremely important for stomachless fish. In this study, all the B. subtilis isolates had the ability to produce cellulase, which was in agreement with other studies [48,49].…”