Isolation and Characterization of Antibiotic-producing Bacteria from the Salt Range of Kallar Kahar, Pakistan




Agar plug method, Antibiotics, Streptomyces, Starch Casein Agar


The emergence of antibiotic resistance in pathogenic bacteria has heightened the need for new antibiotics. Streptomycetes are filamentous gram-positive bacteria that are ubiquitous and present in saline soil and produce antibiotics as secondary metabolites under stressful conditions. Naturally, Streptomyces produce over two-thirds of antibiotics that are used clinically. Saline soil was collected from Kallar Kahar, Pakistan. The soil sample was serially diluted and three dilutions were plated on Streptomyces selection media (starch-casein agar and glucose yeast malt agar) after growing the culture, pure colonies were selected based on their morphological features and subsequently examined using Gram-staining. The antimicrobial activity of two selected strains (P1 and P2) was evaluated using the agar plug method and agar well diffusion method against both gram-positive (Bacillus subtilis) and gram-negative (Escherichia coli) pathogenic bacteria. In the agar plug method, the clear zone of inhibitions was not clearly visible against the test bacteria. The zone of inhibitions were only observed in agar well diffusion assay in which the P1 strain exhibited a diameter of 0.6mm against E. coli and 0.75mm against B. subtilis and the P2 strain showed antibacterial activity only against E. coli with a diameter of 0.75mm. The results were not significant, these slight zones of inhibition warrant further improvements in methods for isolation and purification of antibiotic-producing bacteria. Such methods should aim to enhance the efficiency of antibiotics.


Law JW-F, Tan K-X, Wong SH, Ab Mutalib N-S, Lee L-H. Taxonomic and characterization methods of Streptomyces: a review. Prog Microbes Mol Biol. 2018;1(1):e0000009.

Talbot GH, Jezek A, Murray BE, et al. The Infectious Diseases Society of America’s 10×’20 initiative (10 new systemic antibacterial agents US Food and Drug Administration approved by 2020): is 20×’20 a possibility? Clin Infect Dis. 2019;69(1):1-11.

Rosa L, Andrade-Júnior F, Cordeiro L, et al. Association study between ceftriaxone and a synthetic amide against strains of Pseudomonas aeruginosa. Bra J Biol. 2023;83:e274149.

Akter A, Islam F, Bepary S, et al. CNS depressant activities of Averrhoa carambola leaves extract in thiopental-sodium model of Swiss albino mice: implication for neuro-modulatory properties. Biologia. 2022;77(5):1337-1346.

Bernardini S, Tiezzi A, Laghezza Masci V, Ovidi E. Natural products for human health: an historical overview of the drug discovery approaches. Nat Prod Res. 2018;32(16):1926-1950.

Apreja M, Sharma A, Balda S, et al. Antibiotic residues in environment: antimicrobial resistance development, ecological risks, and bioremediation. Environ Sci Poll Res. 2022:1-17.

Yu T, Yang F, Hou F, Dong J, Song Z, Wang Z. Research Progress on Anti-tumour, Anti-microbial and Anti-viral Activities of Crocodile Blood. IEEE; 2023:13-17.

Abdel-Razek AS, El-Naggar ME, Allam A, Morsy OM, Othman SI. Microbial natural products in drug discovery. 2020;8(4):470.

Ayed A, Slama N, Mankai H, et al. Streptomyces tunisialbus sp. nov., a novel Streptomyces species with antimicrobial activity. Antonie Van Leeuwenhoek. 2018;111:1571-1581.

Hungund BS, Honnangi S, Desai SS, Badiger K, Tennalli GB. Diversity and Classification of Streptomyces. Actinobacteria: Ecology, Diversity, Classification and Extensive Applications. Springer; 2022:89-116.

Bawazir AMA, Shivanna GB, Shantaram M. Impact of Different Media for Growth and Production of Different Soluble Pigments in Actinomycetes Isolated from Soils of Hadhramout, Yemen. Eur J Biomed. 2018;5:615-619.

Valdes-Pena MA, Massaro NP, Lin Y-C, Pierce JGJAocr. Leveraging marine natural products as a platform to tackle bacterial resistance and persistence. Acc of Chem Res. 2021;54(8):1866-1877.

Trenozhnikova L, Azizan A. Discovery of actinomycetes from extreme environments with potential to produce novel antibiotics. Cent Asian J Global Health. 2018;7(1).

Mirsonbol SZ, Issazadeh K, Zarrabi S, Mirpour M. Evaluation of antibacterial activity of new Streptomyces species isolated from soils of eastern Gilan province and optimization of antibacterial compounds produced by it. Int J Mol Clin Microbiol. 2019;9(1):1128-1137.

Baniya A, Singh S, Singh M, et al. Isolation and screening of antibiotics producing Streptomyces spp from the soil collected around the root of Alnus nepalensis from Godawari. Nepal J Biotechnol. 2018;6(1):46-56.

Romano-Armada N, Yañez-Yazlle MF, Irazusta VP, Rajal VB, Moraga N. Potential of bioremediation and PGP traits in Streptomyces as strategies for bio-reclamation of salt-affected soils for agriculture. Pathogens. 2020;9(2):117.

Donald L, Pipite A, Subramani R, Owen J, Keyzers RA, Taufa TJ. Streptomyces: Still the biggest producer of new natural secondary metabolites, a current perspective. Microbiol Res. 2022;13(3):418-465.

Xia H, Zhan X, Mao X-M, Li Y-Q. The regulatory cascades of antibiotic production in Streptomyces. World J Microbiol Biotechnol. 2020;36(1):13.

Goyal K, Goyal A, Awasthi R, Rani N, Kaur RJRJoP, Technology. Synthesis and Biological Evaluation of Nitro-substituted chalcones as potent Antibacterial and Antifungal agents. Res J of Pharm and Technol. 2023;16(4):1931-1939.

Kowalska-Krochmal B, Dudek-Wicher R. The minimum inhibitory concentration of antibiotics: Methods, interpretation, clinical relevance. Pathogens. 2021;10(2):165.




How to Cite

Iftikhar, N., & Khalid, I. (2023). Isolation and Characterization of Antibiotic-producing Bacteria from the Salt Range of Kallar Kahar, Pakistan. TSF Journal of Biology , 1(1), 67–75.