2025, Vol. 6, Issue 2, Part A
Optimizing the production and efficacy of antimicrobial compounds obtained from bacillus species isolated from agricultural sites in Port Harcourt, Nigeria
Author(s): Gloria Chile Amadi-Wali, Owhorchukwu Amadi-Wali and Onyemaechi Collins Micah
Abstract: Antimicrobial resistance has become a global health challenge because infectious microbes continue to develop resistance against available antibiotics. Hence, the urgent need to search for novel antibiotic drugs. This study is aimed at optimizing the production and efficacy of antimicrobial compounds obtained from Bacillus species isolated from agricultural sites in Port Harcourt, Nigeria. Bacillus species were isolated from agricultural sites and identified using standard culture techniques. These Bacillus species were stressed at 300C, 400C and 450C at the pH of 4.0 and 8.0 for 72 hours. The bacterial extract obtained were screened for antimicrobial activity using agar well diffusion technique of the Modified Kirby-Bauer antibiotic susceptibility test against already identified microorganism including Escherichia coli, Klebsiella species, Pseudomonas species and Staphylococus aureus. Visible zone of inhibitions were measured with reference to standard antibiotics used as control. The result of total heterotrophic bacteria counts showed that there was no significant difference in the total heterotrophic bacteria counts of the different depths sampled (p=0.091). At 72hours of incubation, the highest mean of zone of inhibition was recorded at 300C (15.36mm) which is moderately sensitive while at 48hours the lowest mean of zone of inhibition was recorded at 450C (12.49mm). The secretory molecules produced at acidic and alkaline pH by Bacilli isolated from soil surface and 15cm soil depth were moderately sensitive. The mean of zone of inhibitions (ZI) showing the effect of time on isolates from different soil depth showed that the highest mean of ZI was spotted in soil surface at 48hours and 72hours of incubation with an increase in ZI of 2.14mm (ZI 14.36 and 16.50 respectively) after 72 hours of incubation while 5cm depth had the lowest mean of ZI at 48 hours and 72hour (12.17 and 12.98 respectively) with an increase in ZI of 0.81mm after 72hours of incubation. It was discovered that increase in incubation time did not significantly increase the zone of inhibition. Gas Chromatography - Mass Spectrometry (GC-MS) analysis of the bacteria extracts revealed compounds contained in Bacteria extract as Cyclohexasiloxane, dodecamethyl, Dodecanoic acid, 1H-Pyrrolo[3,4-d]pyrimidine-2,5-di one, 4,6-bis(4-hydroxyphenyl), Methyl tetradecanoate, 1H-Pyrrolo[3,4-d]pyrimidine-2,5-di one, 4,6, bis(4-hydroxyphenyl), Cyclododecane, 1-Cyclopenteneacetic acid, 5-oxo- Bicyclo[4.1.1]oct-2-ene. In conclusion, the secretory molecules produced by Bacilli isolated from the soil sampled in this study have antibiotic potential and are chemically similar to the molecules found in phytochemicals such as flavonoids, alkaloids, terpenoids, and phenolic compounds.
DOI: 10.22271/micro.2025.v6.i2a.237
Pages: 48-55 | Views: 567 | Downloads: 128
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How to cite this article:
Gloria Chile Amadi-Wali, Owhorchukwu Amadi-Wali, Onyemaechi Collins Micah. Optimizing the production and efficacy of antimicrobial compounds obtained from bacillus species isolated from agricultural sites in Port Harcourt, Nigeria. J Adv Microbiol Res 2025;6(2):48-55. DOI: 10.22271/micro.2025.v6.i2a.237
