Niemi R M, Niemelä S I
National Board of Waters and the Environment, Helsinki, Finland.
Int J Food Microbiol. 1994 Sep;23(1):71-8. doi: 10.1016/0168-1605(94)90222-4.
Growth of known species of Enterococcus, Lactococcus and Streptococcus and Aerococcus viridans in selective and nonselective liquid media routinely used to enumerate faecal streptococci was measured optically at different temperatures. Growth of environmental isolates was measured in some of these media. Growth of the reference strains on Bile esculin azide agar at elevated incubation temperatures was tested. The results revealed only minor differences between media but strong influence of incubation temperature. Some media tended to yield higher cell densities than others. For many species the inoculum size affected maximum turbidity. To combine selective media with selective incubation temperatures seems to be necessary to achieve satisfactory reliability in traditional liquid enumeration methods for faecal streptococci. Because of the diversity of this group, optimal selectivity and recovery can hardly be achieved simultaneously.
在常用于计数粪链球菌的选择性和非选择性液体培养基中，于不同温度下通过光学方法测定了肠球菌、乳球菌、链球菌的已知菌种以及绿色气球菌的生长情况。还测定了环境分离株在其中一些培养基中的生长情况。测试了参考菌株在升高培养温度的胆汁七叶苷叠氮琼脂上的生长情况。结果显示培养基之间只有微小差异，但培养温度的影响很大。一些培养基往往比其他培养基产生更高的细胞密度。对于许多菌种而言，接种量会影响最大浊度。为了在传统的粪链球菌液体计数方法中获得令人满意的可靠性，似乎有必要将选择性培养基与选择性培养温度相结合。由于该菌群的多样性，很难同时实现最佳的选择性和回收率。
