실내 공기질 관리의 중요성이 대두되면서 쾌적한 실내환경에 도움을 주는 공기청정 기능과 습도 조절 기능을 동시에 갖춘 제습기와 공기청정기가 각광받고 있다. 하지만 오랜 기간 동안 공기정화제품을 사용하게 될 시에는 필터가 오염되어 본연의 기능을 상실하게 되는 것으로 알려져 있지만 이에 대한 구체적인 연구나 보고는 드문 편이다. 이에 본 연구에서는 가정과 사무실 등에서 사용한 공기정화제품을 수거하여 주요 부위별 미생물 오염도 및 주요 오염 미생물들을 분석하였다. 그 결과, 4 종류의 공기정화제품에서 오염도가 높은 부위는 필터부위, 물이 직접 닿는 부위 및 공기가 외부로부터 직접적으로 들어오는 입구부위 등에서 미생물학적 오염도가 가장 높았다. 하지만 공기정화제품은 사용하는 환경과 조건에 따라서 미생물학적 오염도 및 오염 미생물의 성상은 각각 다르게 나타났다. 하지만 이들 공기정화제품들에는 공통적으로 Staphylococcus sp., Micrococcus sp. 그리고 Bacillus sp.의 세균과 Cladosporium sp. 및 Penicillium sp.의 진균이 공통적으로 오염되어 있는 우점종인 것으로 분석되었다.

In order to develop a natural food preservative, the root bark of Morus alba was extracted with several solvents, and then antimicrobial activity was investigated. The optimum extracting condition for the antimicrobial substance from the sample, minimum inhibitory concentration (MIC) of the extracted substance against microorganisms were also examined. The antimicrobial activity of the ethanol extract from the sample was atronger than those of the extracts by the other solvents such as water, methanol, ethyl acetate and acetone. The optimum extracting condition for antimicrobial substance from the sample was shaking extraction twice for 5 hours at room temperature in case of 7 times of absolute ethanol added to the crushed root bark of Morus albs. The ethanol extract from the root bark of Mores albs had strong antimicrobial activity against Gram positive bacteria(MIC, 6.4-19.2 g/ml) such as B. subtilis, B. cereus, L. monocytogenes and S. aureus. Especially, Bacillus species was the most susceptible to the extracted substance. The ethanol extract showed antimicrobial activity against Gram negative bacteria(MIC, 160-1600 g/ml) and yeasts(MIC, 1600 g/ml) such as C. albicans and S. acidifaeciens. The extract also showed growth inhibition against molds such as A. niger, A. parasiticus, A. versicolar and T. uiride.

The effect of the ethanol extract from salviae miltiorrhizae radix (Salvia miltiorrhiza) on the microbial growth and the stability of the extracted antimicrobial material were investigated. The ethanol extract had strong growth inhibition activity (MIC, 3.13-50.0 pg/ml) against Gram-positive bacteria such as B. subtilis, L. monocytogenes and S. aureus. Among Gram-positive bacteria tested, B. subtilis was the most susceptible to the extracted substance. While the antimicrobial activity of the ethanol extract was weak (MIC, 400-800 ug/ml) to E. coli and yeasts (C. albicans. Sacch. diastaticus). The ethanol extract had bactericidal action at higher concentration than MIC against B. subtilis, while the extract had only bacteriostatic action against S. aureus. The extracted antimicrobial substance was stable in the pH range of 4.0 to 10.0, heat treatment at 121℃ for 15 min, and freezing and thawing