Table 2: A number of strains were isolated from Arauca river sediment samples. The number in each column compares the total actinobacteria-like isolates obtained after the applied physicochemical pretreatment versus the total number of isolates with positive antimicrobial bioactivity. Physicochemical pretreatments are abbreviated as follows: U (Sonication); C (Calcium carbonate); M (Microwave); F (Phenol); T (Thermal) and S (Direct Seeding).

Pretreatment Sample Point Total Isolates
Point 1 Point 2 Point 3 Point 4
S 35/5 55/0 22/0 47/4 159/9
C 34/6 34/2 36/1 40/4 144/13
F 51/12 46/1 32/4 29/3 158/20
M 47/11 57/3 24/0 37/3 165/17
U 43/10 41/3 26/1 33/4 143/18
T 4/0 3/0 3/0 11/1 21/1
Total Isolates 214/44 236/9 143/6 197/19 790/78