富锌微生物的筛选及其饲喂鸡的生物学效价评定

Screening of Zinc-Enriched Microorganism and Its Relative Biological Value for Chickens

本试验旨在筛选出能将无机锌高效转化为微生物锌的微生物,并评定其作为锌源饲喂鸡的生物学效价。首先,从实验室已有的16株饲用微生物中筛选出对无机锌具有高转化率的菌株,随后对影响其转化率的无机锌浓度、培养温度、培养时间和菌液接种量进行单因素优化和正交优化。然后,选用18周龄的海兰褐公鸡20只,随机分成4组,每组5个重复,每个重复1只。对照1组和对照2组饲喂无机锌(ZnSO_4·7H_2O),饲粮锌含量分别为60和90 mg/kg;试验组1和试验2组饲喂酵母锌,饲粮锌含量也分别为60和90 mg/kg。预试期和正试期各5 d。结果表明:58号菌种(酿酒酵母菌)为最优无机锌转化菌,无机锌转化为微生物锌的转化率达52.68%;在无机锌浓度1.5 mg/L、菌液接种量4%、28℃条件下培养66 h,其对无机锌转化为微生物锌的转化效率可达98.01%;以该菌种转化的富锌酵母菌(酵母锌)饲喂鸡,其中锌相对于硫酸锌中锌的相对生物学效价为114.83%。由此可见,58号菌种是一种对无机锌具有高转化率的富锌微生物。

The purpose of this experiment was to screen out the microorganism that can efficiently transform inorganic zinc into microbial zinc,and to evaluate the biological value of the zinc source for feeding chickens.First,from the 16 strains of laboratory microorganisms available in the laboratory,strains with a high conversion rate to inorganic zinc were selected,and then the factors such as inorganic zinc concentration,culture temperature,culture time and inoculum quantity of bacteria were affected thought single factor optimization and orthogonal optimization.Then,twenty Hy-Line cocks at 18-week-old were randomly divided into 4 groups with 45 replicates per group and 1 chick per replicate.Chicks in the control group 1 and control group 2 fed the inorganic zinc(ZnSO 4·7H 2O),dietary zinc contents were 60 and 90 mg/kg,respectively;chicks in the test group 1 and test group 2 fed the yeast zinc,dietary zinc contents were 60 and 90 mg/kg,respectively.Each the pre trial period and the trial period were 5 days.The results showed that No.58 strain(Saccharomyces cerevisiae)was the optimal inorganic zinc transforming strain,its inorganic zinc to microbial zinc conversion rate was 52.68%;under the condition of inorganic zinc concentration 1.5 mg/L,inoculum quantity of bacteria 4%and temperature 28℃cultured for 66 h,the inorganic zinc to microbial zinc conversion rate could add up to 98.01%.Used the zinc-enriched yeast(yeast zinc)transform by the strain fed to chickens,the relative biological value of zinc in yeast zinc relative to zinc in zinc sulfate was 114.83%.In conclusion,No.58 strain is a zinc-enriched microorganism with a high conversion rate to inorganic zinc.