The purpose of this study is to examine the bio-corrosion of an ancient knife that was discovered in burial soil and to assess the effectiveness of garlic extract (GAE) as a biocide. The knife was swabbed for microorganisms, and those organisms were subsequently cultured in tryptic soy broth at 37 degrees Celsius for 24 hours. The knife was analyzed using scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), the corrosion products were analyzed using X-ray diffraction, and the garlic extract was analyzed using gas chromatography-mass spectrometry (GCMS) and Fourier transform infrared spectroscopy (FT-IR). Coupons constructed of synthetic materials with the same chemical composition as the knife under study were manufactured and then submitted to isolated species of bacteria to examine the behavior of microbial corrosion. Scanning electron microscopy was used to examine the biofilm that had formed on the coupons' surfaces. Results indicated that the knife's blade seemed to be made of carbon steel and that five distinct species of bacteria and six different types of fungus were found. The bacteria were determined to consist of four distinct species of iron-oxidizing bacteria (IOB) and one kind of acid-producing bacteria (APB). Sessile IOB was quantified in terms of CFU to examine the bacterial proliferation on the agar plate's surface. A compound in GAE that is rich in sulfur and may block the development of bacteria was discovered using GCMS. The active ingredient in garlic responsible for its antibacterial properties against both Gram-positive and Gram-negative bacteria is allicin. Therefore, GAE may be offered as a natural biocide to replace more hazardous commercial biocides.