Molecular identification of locally isolated bacteria from soil in Thiqar governorate and ability to produced antibiotics

Abstract EN

The objective of this study was to isolate and diagnose local bacterial isolates produced antimicrobials from some soil in Thiqar governorate and detecting the presence of 16SrRNA gene using DNA Sequence technique.

The study included collected 25 soil samples from different regions of Thiqar Governorate, 13 bacterial isolates wasisolated depending on shapes and colors, RL1 and RL2.These isolates were identified by biochemical tests.

They were identified as Bacillus isolates and were also identified using Vitek 2.

The technique was able to diagnose only 7 isolates.

The isolates were then tested to produce antimicrobial agents against 5 known bacterial pathogens Klebsiella pneumoniae, Proteus mirabilis, Pseudomonasaeruginosa, Staphylococcus aureus, Salmonella typhi.

Most isolates showed a positive result against these pathogenic bacteria and then isolated 9 isolates using 16SrRNA gene for PCR products.

All isolates were positive for this gene.

After treatment for each isolate using Mega 6 program, and obtained new isolate and get code MF423696 after matching them with NCBI.

And 5 isolates were selected for the purpose of completing the study.

The antibiotic was then extraction by centrifugation at 10.000 cycles / minute for 15 minutes and then filtered using 0.22µm micrometer filter.

It was used to inhibit the pathogenic bacteria.

A set of specific reagents was carried out to identify the active substances found in the extract including detection of phenols, flavonoids, amines, and saponins.

All isolates were positive for phenols, flavonoids, amines, and saponins except RL2 that showed negative to this test.