Germs need an alkaline environment in which to thrive and multiply, making lemon juice a natural enemy due to its rich acid content. One oz. of pure lemon juice contains 1.44 g of citric acid.
Lab studies support the effectiveness of lemon juice as an antibacterial. The Leptospirosis Information Center finds the citric acid in lemon juice a suitable substitute for chemical cleaners. Leptospirosis is a bacteria that can cause disease in animals and humans, and is not tolerant of acids.
In a 1993 test to determine the effectiveness of lemon juice in purifying water in Argentina, the National Center for Biotechnology Information reported a significant reduction in the v. cholera bacterium as long as enough lemon juice was used to lower the water's alkalinity levels, which encourage bacterial growth.
Because of its properties as a germ killer, lemon juice can serve as an effective and natural alternative to household disinfectants, as well as a natural freshener.
Rachel Lovejoy has been writing professionally since 1990 and currently writes a weekly column entitled "From the Urban Wilderness" for the Journal Tribune in Biddeford, Maine, as well as short novellas for Amazon Kindle. Lovejoy graduated from the University of Southern Maine in 1996 with a Bachelor of Arts in English.