Hu Y.,Huazhong Agricultural University |
Hu Y.,Hubei Collaborative Innovation Center for Industrial Fermentation |
Hu Y.,Hubei Normal University |
Qin H.,Huazhong Agricultural University |
And 10 more authors.
Biotechnology and Biotechnological Equipment | Year: 2016
Saccharomyces boulardii preparations are promising probiotics and clinical agents for animals and humans. This work focused on optimizing the nutritional conditions for the production of S. boulardii in solid-state fermentation by using classical and statistical methods. In single-factor experiments, the S. boulardii production was significantly increased by the addition of glucoamylase and the optimal carbon and nitrogen sources were found to be soluble starch and NH4Cl, respectively. The effects of the glucoamylase, soluble starch and NH4Cl on S. boulardii production were evaluated by a three-level three-factor Box-Behnken design and response surface methodology (RSM). The maximal yeast count (4.50 × 109CFU/g) was obtained under the optimized conditions (198 U/g glucoamylase, 2.37% soluble starch and 0.9% NH4Cl), which was in a good agreement with the predicted value of the model. This study has provided useful information on how to improve the accumulation of yeast cells by RSM. © 2015 The Author(s). Published by Taylor & Francis.
Liu L.,Huazhong Agricultural University |
Zhou Y.,Sunhy Biology Co. |
Wu J.,Huazhong Agricultural University |
Zhang W.,Huazhong Agricultural University |
And 3 more authors.
Aquaculture Research | Year: 2014
A feeding trial was conducted for 8 weeks to evaluate the effects of graded levels of neutral phytase supplementation using pretreatment or spraying method on growth performance, body composition, bone mineral content and serum biochemical parameter in grass carp, Ctenopharyngodon idellus. A control diet without phytase was added and six additional diets were arranged as a 2 × 3 factorial with two methods (pretreatment or spraying) and three levels of phytase (500, 1000 or 1500 U kg-1). The results showed that supplemental phytase at different levels in the diet and with different application methods all improved weight gain, specific growth rate and protein efficiency ratio of grass carp (P < 0.05). The feed conversion ratio in phytase-supplemented groups was lower than the control. Dietary phytase addition reduced the lipid content in the whole body of grass carp. Phytase supplementation with different method increased ash and mineral (P, Ca, Mg and Zn) contents in whole-body and vertebra (P < 0.05). The increase in these mineral contents was also observed in the serum. Based on the results, we may conclude that: 1) supplemental dietary phytase, regardless of the application methodology, improved the growth performance and nutrient utilization in grass carp; 2) the pretreatment mode of phytase application was more effective than spraying at the same phytase level. © 2013 John Wiley & Sons Ltd.
Liu L.W.,Huazhong Agricultural University |
Luo Y.L.,Huazhong Agricultural University |
Hou H.L.,SunHY Biology Co. |
Pan J.,Yunnan New Ocean Food Co. |
Zhang W.,SunHY Biology Co.
Journal of Applied Ichthyology | Year: 2013
A 9-week experiment was designed to study the effects of partial replacement of monocalcium phosphate (MCP) with neutral phytase on growth, body compositions, serum biochemical statuses and intestinal digestive enzyme activities of grass carp, Ctenopharyngodon idellus. The control diet (designated as P2.0) was prepared with 2.0% MCP but without phytase. The three other diets (designated as PP1.5, PP1.0 and PP0.5, respectively) were supplemented with 1.5, 1.0 and 0.5% MCP, respectively, along with 500 FTU of neutral phytase kg-1 diet in each. After a 9-week feeding trial, fish (initial body weight: 43.44 ± 2.37 g) fed with PP1.5 and PP1.0 had no significant change in weight gain (WG), specific growth rate (SGR), protein efficiency rate (PER) or feed conversion ratio (FCR) compared with the control (P > 0.05) whereas fish fed with PP0.5 showed significantly lower growth performance in the above parameters. The crude lipid content in whole body or muscle of the fish fed with PP1.5 was significantly lower than the control while significantly higher in fish fed with PP0.5 (P < 0.05), whereas no obvious change was observed in the fish fed with PP1.0. For serum indices, higher serum alkaline phosphatase (Alkp), phosphorus (P) and calcium (Ca) contents were observed in fish fed with phytase-supplemented diets in comparison with the control. In addition, dietary phytase supplementation increased amylase activity and decreased lipase activity in both foregut and hindgut. The present study suggests that dietary MCP can be reduced when neutral phytase is added to the grass carp diet, and that the maximum MCP reduction level can be up to 1% when neutral phytase is supplemented at 500 FTU kg-1 diet. © 2012 Blackwell Verlag GmbH.