硒酵母的培养及其养虾效果

对五株假丝酵母菌株进行利用淀粉废水和转化硒元素的筛选试验,其中CY-173菌株所得的蛋白质含量和蛋白态硒总量最多.对其进行耐高温试验,在33～45℃范围内,菌株都能生长,但超过40℃生长速度开始减缓,45℃时明显受到抑制.在6L标准发酵罐内进行pH与温度条件试验,pH在3～5之间,菌株生长差异不显著;在33～40℃范围内,菌株都能较好生长,但以37℃的蛋白质含量与蛋白态硒总量为最高.将所得的硒酵母替代部分鱼粉用于养殖中国对虾,结果三组硒酵母饲料(含10%、20%、30%硒酵母)的养殖效果均优于对照饲料,其中10%硒酵母添加量的饲料(含硒0.6×10-6),其饵料系数最低,为2.56,比对照组的2.95减少了13.3%.

Culture of selenium yeast and its application of the yeast to shrimp culture

The selecting experiment on ut ilizing starch wastewater by f ive Candida tropicalis strains and their transforming of selenium were studied. The result s showed that the strain of CY-173 produced more protein and protein-form selenium than the others . The temperature tolerance test proved that the bacteria were able to grow upto 33- 45 e . The growth rate slowed down when temperature were above 40 e and the growth was inhibited at 45 e . An experiment concerning the ef fects of pH and temperatures on their growth rate and the amount of protein produced was also carried out in a standard 6-liter tun. The dif ference of growth rates of the strains was not significant at pH 3- 5 , and they could grow normally at 33- 40 e . The amounts of protein and protein-form selenium produced by the strains reached the highest level at 37 e .Feed with the seleniumrich yeast was used in the culture of Penaeus chinensis . The results showed that the three groups fed with the selenium-rich yeast ( containing 10% , 20%, 30% selenium yeast ) had better effect s than the control group , and the group with 10% of the yeast ( containing 0. 6 @ 10 - 6 selenium ) had the lowest feed rat io, 2. 56, reducing 13. 3% compared with the control group.