Treatment of Air Filters Using the Antimicrobial Natural Products Propolis and Grapefruit Seed Extract for Deactivation of Bioaerosols

Abstract

Two natural products; i.e., grapefruit seed extract (GSE) and propolis, were investigated for use in antimicrobial air filters. Staphylococcus aureus was investigated as a test bioaerosol, and was deposited on the antimicrobial filters, which were treated by spraying with various areal densities of GSE and propolis. The pressure drop and particle penetration were investigated to assess the filtration performance of the bioaerosol, and the bacterialinactivation performance of the filters was evaluated by quantifying S. aureus. There was little change in the pressure drop as a function of the areal density of GSE up to 185.9 mg/ cm 2 ; however, a significant change in the pressure drop was found for the air filter coated with propolis at an areal density of 98.4 mg/cm 2 . The penetration levels of bioaerosols in both filters were uniform and in the range 1.4-2.0% (based on particle number), regardless of the areal density of the deposited GSE or propolis. The inactivation rates of the filters with identical deposition masses of GSE and propolis were similar in the ranges of 92. 1-100%, 75.2-89.1%, and 54.4-75.5% at the control filters with colony numbers of 10 3 , 10 4 , and 10 5 CFU/mL, respectively. The bacterial inactivation rate could be described by an exponential function of the areal density of GSE/propolis per number of colonies.

New emerging fields of application of propolis

“…Ethanol extract Korea [117,118] Effect on the ruminal degradation of nutrients and reduction of methanogenesis in ruminants 70 % ethanol extract Brazilian red Egyptian brown [119] Closely related to food preservation is the application of propolis as a constituent of the socalled active packaging materials, based on the incorporation of active substances, mainly natural antimicrobial and antioxidant agents, in food biopackaging materials [105]. Its incorporation in polylactic acid films, and films obtained from starch and cellulose nanocrystals, has given excellent results in the preservation of cheese, butter [104] and bell peppers [103].…”

Chemical Analysis and Antimicrobial Effect of Propolis from Hakkari Province of Turkey against Some Pathogenic Microorganisms

“…Along with the rising interest in natural products, propolis has been a promising source for discovering new drugs (10). For this reason, propolis has been extensively studied especially due to its chemical structure and biological properties in recent years (11,12).…”

Recent advances in antimicrobial air filter

“…Depositing nanoparticle of antimicrobial agent onto membrane surface may be conducted by dip-coating [13,36,40,[54][55][56], layer-by-layer coating [44], spray coating [46], nebulization process (aerosol process) [34,37,38,42,48], and electro-spraying [4,43,49]. Illustrations of the methods are shown in Fig.…”