Grieves R B, Wang S L
Appl Microbiol. 1967 Jan;15(1):76-81. doi: 10.1128/am.15.1.76-81.1967.
An experimental investigation established the effect of the presence of inorganic salts on the foam separation of Pseudomonas fluorescens and of Bacillus subtilis var. niger (B. globigii) from aqueous suspension by use of a cationic surfactant. For P. fluorescens, 5.0 mueq/ml of NaCl, KCl, Na(2)SO(4), K(2)SO(4), CaCl(2), CaSO(4), MgCl(2), or MgSO(4) produced increases in the cell concentration in the residual suspension (not carried into the foam) from 2.9 x 10(5) up to 1.6 x 10(6) to 2.8 x 10(7) cells per milliliter (initial suspensions contain from 3.3 x 10(7) to 4.8 x 10(7) cells per milliliter). The exceptional influence of magnesium was overcome by bringing the cells into contact first with the surfactant and then the salt. For B. subtilis, the presence of 5.0 mueq/ml of any of the eight salts increased the residual cell concentration by one order of magnitude from 1.2 x 10(4) to about 4.0 x 10(5) cells per milliliter. This occurred regardless of the sequence of contact as long as the surfactant contact period was sufficient. The presence of salts increased collapsed foam volumes with P. fluorescens and decreased collapsed foam volumes with B. subtilis.
一项实验研究确定了无机盐的存在对荧光假单胞菌和枯草芽孢杆菌变种尼日尔（球形芽孢杆菌）从水悬浮液中通过使用阳离子表面活性剂进行泡沫分离的影响。对于荧光假单胞菌，5.0微当量/毫升的氯化钠、氯化钾、硫酸钠、硫酸钾、氯化钙、硫酸钙、氯化镁或硫酸镁使残余悬浮液（未进入泡沫中的）中的细胞浓度从每毫升2.9×10⁵增加到1.6×10⁶至2.8×10⁷个细胞（初始悬浮液每毫升含有3.3×10⁷至4.8×10⁷个细胞）。通过先使细胞与表面活性剂接触然后再与盐接触，克服了镁的特殊影响。对于枯草芽孢杆菌，5.0微当量/毫升的八种盐中的任何一种的存在使残余细胞浓度从每毫升1.2×10⁴增加一个数量级至约4.0×10⁵个细胞。只要表面活性剂接触时间足够，无论接触顺序如何都会发生这种情况。盐的存在使荧光假单胞菌的泡沫塌陷体积增加，而使枯草芽孢杆菌的泡沫塌陷体积减小。
