Antimicrobial Potential of Streptomyces spp. Isolated from the Rift Valley Regions of Ethiopia

Table 2

Inhibition zone of the actinomycete isolates against the test pathogens.

Test pathogens
S.No.	Isolates code	Gram-negative bacteria					Gram-positive bacteria		Fungi
		Ec	Kp	Pa	St1	St2	Sa	Se	A. niger
1	RVE002	32 ± 0.45	30 ± 0.20	27 ± 0.20	17 ± 0.58	20 ± 0.96	12 ± 0.35	20 ± 0.30	22 ± 0.58
2	RVE004	—	14 ± 0.31	14 ± 0.50	24 ± 0.16	28 ± 0.65	27 ± 0.77	21 ± 0.30	11 ± 0.6
3	RVE029	24 ± 0.45	—	—	13 ± 0.16	15 ± 0.96	25 ± 0.77	26 ± 0.30	14 ± 0.6
4	RVE077	17 ± 0.33	8 ± 0.20	27 ± 0.50	—	—	10 ± 0.50	13 ± 0.58	20 ± 0.0
5	RVE116	16 ± 0.20	22 ± 0.50	—	15 ± 0.60	—	16 ± 0.58	15 ± 1.16	12 ± 0.58
6	RVE118	15 ± 0.20	12 ± 0.50	16 ± 0.58	17 ± 0.60	17 ± 0.65	20 ± 1.00	20 ± 0.80	17 ± 1.20
7	RVE125	25 ± 0.33	5 ± 0.31		15 ± 0.96	27 ± 1.00	30 ± 0.60	30 ± 0.60	10 ± 0.00
8	RVE129	>35	22 ± 0.36	17 ± 0.40	>31	>31	>35	>40	30 ± 0.0
9	RVE133	22 ± 0.60	30 ± 0.31	25 ± 0.40	22 ± 0.58	28 ± 1.00	20 ± 1.00	10 ± 0.60	18 ± 0.58
10	RVE144	18 ± 0.45	—	–	26 ± 0.58	19 ± 1.00	21 ± 0.50	—	10 ± 0.88
11	RVE165	10 ± 0.60	—	25 ± 0.40	12 ± 0.58	12 ± 0.36	12 ± 0.50	—	12 ± 0.58
12	RVE172	20 ± 0.60	19 ± 0.31	32 ± 0.58	—	29 ± 0.50	12 ± 0.50	14 ± 0.40	—
13	RVE187	>31	27 ± 0.31	28 ± 0.10	>35	>35	>40	>40	27 ± 0.0
14	RVE193	15 ± 0.33	7 ± 0.50	5 ± 0.10	17 ± 0.60	21 ± 1.00	20 ± 0.35	22 ± 1.16	10 ± 0.58
15	RVE194	13 ± 0.33	18 ± 0.50	19 ± 0.58	15 ± 0.60	18 ± 1.00	16 ± 1.16	16 ± 1.16	17 ± 0.60
16	RVE214	15 ± 0.33	18 ± 0.36	20 ± 0.20	16 ± 0.80	15 ± 0.50	32 ± 0.35	33 ± 0.58	18 ± 1.20
17	RVE217	28 ± 0.20	18 ± 0.36	28 ± 0.20	>35	>35	>35	>35	30 ± 0.0
18	RVE219	18 ± 0.20	19 ± 0.50	18 ± 0.40	—	—	17 ± 0.58	14 ± 0.80	20 ± 0.6
19	RVE226	15 ± 0.45	22 ± 0.36	18 ± 0.58	15 ± 0.8	10 ± 0.65	33 ± 0.50	33 ± 0.58	—
20	RVE227	21 ± 0.20	16 ± 0.20	25 ± 0.40	22 ± 0.16	16 ± 0.36	17 ± 0.58	—	18 ± 0.6
21	RVE234	25 ± 0.33	15 ± 0.31	9 ± 0.10	31 ± 0.58	20 ± 0.50	11 ± 1.00	14 ± 0.30	—
22	RVE239	—	8 ± 0.36	8 ± 0.10	10 ± 0.58	14 ± 0.50	24 ± 0.77	34 ± 0.30	11 ± 0.58
23	RVE257	21 ± 0.45	—	—	16 ± 0.58	15 ± 1.00	26 ± 0.77	6 ± 0.30	14 ± 0.58
24	RVE258	19 ± 0.60	—	21 ± 0.20	30 ± 0.16	19 ± 0.36	15 ± 0.77	13 ± 0.58	20 ± 0.0

Note: values are mean of three replicates ± standard deviation (SD). (—): no antimicrobial activity; Sa: Staphylococcus aureus; Ec: Escherichia coli; Pa: Pseudomonas aeruginosa; Kp: Klebsiella pneumoniae; St1: Salmonella typhi ATCC-13311; St2: Salmonella typhi ATCC-14028; Se: Staphylococcus epidermidis; A. niger.