In vitro Vulnerability of Aspergillus niger, Aspergillus fumigatus, Pseudomonas aeruginosa and Xanthomonas campestris to Bioactivities of Garlic (Allium sativum) and Ginger (Zingiber officinale) Extracts

Abstract

Bacterial and fungal pathogens caused diseases on plant that lead to economic losses. These losses adversely influences agricultural productivity by declining crop yields. Prevalent resistance of plant pathogens to synthetic antimicrobial agents elicits seeking alternative plant-based biocides. This study aimed at evaluating the antimicrobial activities of ginger (Zingiber officinale) and garlic (Allium sativum) against selected bacterial and fungal pathogens using different solvents for extractions. The percentage yields of ethanolic extract from both ginger (4.4%) and garlic (3.3%) were higher compared with aqueous extract from ginger (3.2%) and garlic (2.4%). Ethanolic extract from garlic at 100mg/mL exhibited the most effective antibacterial capacity against Pseudomonas aeruginosa (17.20mm) and Xanthomonas campestris (16.20mm), as well as antifungal activities on Aspergillus niger (12.90 mm) and A. fumigatus (9.20 mm). Similarly, ethanolic extract from ginger at 100mg/mL exhibited higher antibacterial and antifungal activity on P. aeruginosa (11.22 mm) and A. niger(11.21 mm) respectively. The minimum bactericidal concentration (MBC) and minimum fungicidal concentration (MFC) results showed that garlic had lower MBC values for both bacterial pathogens (3.125mg/mL) and higher fungicidal activity against A. niger (MFC 25 mg/mL). Ginger exhibited stronger fungicidal activity than garlic, with lower MFC values (6.5 mg/mL for A. niger). This research showcased both garlic and ginger ethanolic extracts as significant antimicrobial agents, as garlic exhibited more antibacterial activity while ginger demonstrated stronger antifungal capacity. Thus, this study lends credence to the potential of the test plants as natural and alternative plant disease control agents.