Name of bacteria and total number of strains Drop collapse assaya Oil spreading assayb Surface tension (mN/m)c
Bacillus cereus (3) B. megaterium (3) B. subtilis (4) Branhamella catarrhalis (2)
Citrobacter intermedius (5) Corynebacterium kutscheri (15) C. xerosis (2) Enterobacter aerogenes (2)
Escherichia coli (6)
Klebsiella ozaenae (5)
Lactobacillus casei (2)
L. delbrueckii (2)
Proteus inconstans (6)
Pseudomonas aeruginosa (23) P. fluorescens (1)
P. diminuta (12)
P. mallei (9)
Staphylococcus aureus (3)
Triton X-100 		+(2) ++(1)
+++(2)
++(1)
+++(3)
NA
NA ++(4)
+++(11)
+(1) +(2)
+(5)
NA
+(1)
++(2)
+(5)
++(5)
+++(18)
++(1)
+(10)
+(6)
+(2)
+++		 +(2) ++(1)
+++(2)
++(2)
+++(2)
NA
NA ++(3)
+++(12)
+(1) +(2)
+(5)
NA
+(1)
++(2)
+(5)
++(4)
+++(19)
++(1)
+(10)
+(5)
+(2)
+++		 +(1)
++(2)
+(1)
+++(2)
+(2)
++(2)
NA
NA
NA
++(13)
+++(2)
+(1)
++(1)
+(2)
+(3)
NA
+(2)
++(2)
+(4)
++(3)
+++(20)
+(1)
+(10)
+(4)
+(1)
+++
Drop collapse assaya: ‘NA’- no drop collapse activity, ‘+++’- drop collapse within 1 minute, ‘++’- drop collapse after 1minute and ‘+’ - drop collapse after 3 minutes of biosurfactant addition.
Oil spreading assayb: ‘NA’ - no oil spreading activity, ‘+’ - oil spreading with a clear zone of 0.5-1.5 cm, ‘++’ - oil spreading with a clear zone of 1.6 to 2.5 cm, ‘+++’ - oil spreading with a clear zone of 2.6 to 3.5 cm.
Surface tensionc: ‘NA’- no surfactant activity, ‘+++’- surface tension <40 mN/m ‘++’- surface tension 40 to 50,’+’- surface tension 51 to 70.
Values in () near ‘+’ sign are the number of positive strains in that category. Values in () near bacterial name are the total number of strains isolated.
Table 3: Drop collapse, oil spreading assays and surface tension measurement.