Table 4.

Antibacterial studies of sisal fibers.

Sisal Modification	Bacteria	Type	Method	Result	Ref
Sisal Extracts
Sisal extract	Escherichia coli	Gram- negative	Disc diffusion—Qualitative method, absence or presence of a zone of inhibition in different concentrations	Significant inhibition, with zones or rings of inhibition of 10.69–12.17 mm. In addition, if the bacterial population is lower, the growth-inhibitory properties of the sisal extract could be improved	[103]
	Bacillus stearothermophilus	Gram- positive	Delvo test SP-NT kit—Broad spectrum microbial inhibition and antibiotic residues test—Colorimetric method: Purple color means to contain an inhibitor and Yellow color does not contain an inhibitor of microbial growth	100% inhibition—All samples were purple
Aqueous Sisal extract	Staphylococcus aureus	Gram- positive	Two methods: Agar well diffusion method in vitro, absence or presence of a zone of inhibition in different concentrations. The test tube dilution method determines levels of resistance to an antimicrobial substance and measures minimum inhibitory concentration (MIC)	Significant inhibition, with zones or rings of inhibition of 29 mm. Its MIC of 10 mg/mL demonstrated significant biological activity against the test pathogenic organisms	[104]
	Salmonella typhi	Gram- negative		Significant inhibition, with zones or rings of inhibition of 27 mm. Its MIC of 20 mg/mL demonstrated a medium biological activity against the test pathogenic organisms
Non-Modified Sisal Fibers
Sisal fibers	Escherichia coli	Gram- negative	Microtiter plate biofilm assay semiquantitative assessment of the biofilm. Measure the optical density (OD) and classify it into strong, moderate, or weak biofilm creators	Microtiter plate biofilm assay semiquantitative assessment of the biofilm. Measure the optical density (OD) and classify it into strong, moderate, or weak biofilm creators	[101]
Modified Sisal Fibers
Sisal-based activated carbon fibers	Escherichia coli	Gram- negative	The flasks with fibers and bacteria were shaken at 37°C for different periods. Surviving bacteria in the solution after contact with samples were counted by the spread plate culture method. The survival amount of bacteria (CFU/mL) was counted from the colony formed on the medium.	Completely kill E. coli at the concentration of 5 × 108 CFU/mL in 8 h	[105]