Preparation Processes Of Enteromorpha Prolifera Base Biological Feed And Its Application To Apostichopus Japonicus Culture

This paper put the Enteromorpha prolifera as the research object, and studied the optimum process of using Brewer’s yeast to degrade E.prolifera and evaluated the effects of adding E.prolifera and microbial fermentation on juvenile sea cucumbers and achieved the preparation technology for the Enteromorpha-biological feed. Laboratory studies were conducted in Aquatic Animal Nutrition Laboratory at Yellow Sea Fisheries Research Institute, Qingdao. Feeding trials were conducted in Qingdao Ruizi Seafood Development Co.,LTD. Results of this paper are presented as follows:1. In order to studied the optimum process of using Brewer’s yeast to degrade E.prolifera, this trial used 3×4 orthogonal experiment design with the powder of E.prolifera as fermentation substrate and Brewer’s yeast fungus liquid as fermented liquid. The results showed as follows: Each strain concentration in the fermentation product was between 2.2 × 106 to 9.2 × 107, and the content of reducing sugar and soluble protein had changed. Finally, this study gained the best fermentation condition, moisture content 60%, bacterial inoculum 10%, fermentation time 2d and temperature at 35 ℃.2. A 46-day feeding trial was conducted to evaluate the effects of adding E.prolifera and microbial fermentation on growth, digestion and non-specific immune of juvenile sea cucumbers(Apostichopus japonicus Selenka). Main sources included Enteromorpha prolifera, Sargassum polycystum,Sargassum thunbergii,U.lactuca and so on. Five diets were formulated to contain 0,10%, 20 %, 30 %, 40 % of E.prolifera,respectively. Half of each diet was fermented by the suspension of Brewer’s yeast. The trial finally had 10 experimental diets. Each diet was randomly fed to one group with 3 replicates of 30 sea cucumber [average body weight of(3.94±0.46)g]. The results showed as follows: 1) the weight gain rate(WGR),specific growth rate(SGR), and feed efficiency(FE) of sea cucumbers were increased with increasing of E.prolifera adding ratio increasing among the non-fermented groups, and the group of 40% E.prolifera was the best; the WGR, SGR and FE of sea cucumbers were firstly increased and then decreased with E.prolifera adding ratio increasing among the fermented groups, and the group of 30% E.prolifera was the best. The WGR, SGR and FE in the group of 30% and 40% E.prolifera were not significantly different(P>0.05), but all of them were significantly higher than those in the group of 10% E. prolifera(P<0.05). The growth performance indices of sea cucumbers were not significantly affected by microbial fermentation(P>0.05). 2) The intestinal cellulase activity was increased in the first stage and then decreased with E.prolifera adding ratio increasing among the non-fermented groups. However, the intestinal cellulase activity tended to increase with E.prolifera adding ratio increasing among the fermented groups. In the same adding ratio, the intestinal cellulase activity in the fermented groups was higher than that in the non-fermented groups, and the significant differences were found when adding ratios were 10%, 20%, and 40%(P<0.05). 3) The superoxide dismutase(SOD), acid phosphatase(ACP) and alkaline phosphatase(AKP) of coelomic fluid were not significantly affected by yes or no fermentation and E.prolifera adding ratio(P>0.05). It can be concluded that the optimal adding ratio of E.prolifera in the diet of juvenile sea cucumber is between 30% and 40%. And microbial fermentation can promote the intestinal cellulase activity of juvenile sea cucumber to some extent.3. The purpose of this study was to explore the processing conditions for the production of Enteromorpha-Biological feed hydrolyzed by alkaline protease and fermented by Brewer’s yeast. An orthogonal array design based on single factor experiments was employed to examine the influence of concentration of alkaline protease, inoculum amount, temperature and time on fermentation conditions. It was found that the content of total soluble protein had significantly changed after hydrolyzed by alkaline protease and the group of 8‰ alkaline protease had no significant difference with 6‰ and 10‰ but significantly higher than other groups.The order of factors of influencing on fermentation obtained by analyzing the data of the reducing sugar in range-method was time, moisture content, inoculum size and adding ratio of alkaline protease, respectively. The optimal processing conditions were firstly hydrolyzed by alkaline protease of 6 ‰(conditions: 50 ℃, 2.5 h), then fermented by Brewer’s yeast at 30℃ for 24 h with an inoculum amount of 16 %.4. A 42-day feeding trial was conducted to evaluate the effects of five different kind of Enteromorpha-Biological feed(got by five treatment on diets in above trial) on growth, digestion and non-specific immune of juvenile sea cucumbers. Each diet was fed to juvenile sea cucumber [ average body weight of(3.94 ± 0.46) g ]. The results showed as follows: 1) The R of sea cucumbers had no difference among groups(P>0.05). The SR of the composite-group had no significant difference with the controlgroup and the fermented-group(P>0.05), but was significantly below the fluid-group and higher than the hydrolyzed-group(P<0.05). The above law can be applied to the WGR, SGR and FC. 2) The AMS activity of fermented-group and control-group in second, forth, sixth week had no difference(P>0.05), but was significantly higher than hydrolyzed-group and below fluid-group and composite-group(P<0.05). The Cellulase activity of composite-group was significantly higher than that in controlgroup and hydrolyzed-group in second, fourth week(P<0.05), but significantly higher than other groups in sixth week(P<0.05). The TRY activity of fermented-group was significantly higher than that of hydrolyzed-group in forth week(P<0.05), and significantly below other groups(P<0.05). The TRY activity of composite-group had no significant difference with the control-group and the fluid-group(P>0.05), but was significantly higher than that of the hydrolyzed-group and higher than fermented-group(P<0.05) in sixth week.3) The ACP、AKP and SOD of coelomic fluid had significant difference among groups(P>0.05). The activity of ACP in fluid-group had no significant difference with composite-group(P>0.05) but was significantly higher than other groups(P<0.05). The activity of AKP in fluid-group and composite-group was significantly higher than hydrolyzed-group and control-group but had no significant difference with fermented-group(P>0.05). There was no difference among the SOD of each group.