Statista報告稱，2017年全球除臭劑市場估計價值約為699.1億美元。幾 乎 90％的18-29歲的青少年每天都在使用除臭劑。二乙酰基或2,3-丁二酮是導 致人類出汗惡臭的主要成分之一。Staphylococcus epidermidis (S. epidermidis)是 人類汗液中細菌之一。葡萄球菌細菌可以發酵甘油或乳酸以形成短鏈（C2- C3）揮發性脂肪 酸（VFA），如乙酸和丙酸。另外細菌可以將支鏈脂肪族氨 基酸轉化為高 度有氣味的短鏈（C4-C5）甲基支化的VFA，如異戊酸。這些 細菌代謝丙 酮酸，產生α-乙酰乳酸作為中間體，隨後通過氧化脫羧將α-乙酰乳酸非酶促轉化為二乙酰。 L乳酸是汗液中表皮葡萄球菌發酵的主要碳源， 以產生二乙酰。 我們設計了一種新的裝置，將表皮葡萄球菌培養物與GASTEC TUBES 92L（GT 92L）連接來測量當L-乳酸存在或不存在 ,雙乙酰生成量的變化。使用5-甲 基糠醛（5-MF）在表皮葡萄球菌L-乳酸發酵生產雙乙酰反應中作為 抑製劑。在 進行最大殺菌濃度（MBC）測試，我們發現0.15％的5-MF對表皮 葡萄球菌以及 CCD106KERTr角質形成細胞不具有毒性。在L-乳酸鹽存在下 培養表皮葡萄 球菌與5-MF明顯降低雙乙酰產生。我們的研究結果介紹了一種 檢測人類皮膚共生細菌發酵產生的惡臭的新設備，並提出5-MF作為下一代除 臭劑開發的 化合物具有巨大潛力。 關鍵字：二乙酰、甲基糠醛、揮發性脂肪酸、人類 角質形成細胞、GASTEC;5-methyl furfural inhibits the fermentation of L-lactate Staphylococcus epidermidis and diacetyl production: A potential novel deodorant targeting bacterial ermentation in human sweats
Statista reports that the global market of deodorants in 2017 is estimated to be worth about 69.91 billion US dollars. Almost 90% of teenagers aged 18-29 years are using deodorants every day. Diacetyl, or 2, 3-butanedione, is one of major components responsible for malodour in human sweats. Staphylococcus bacteria such as Staphylococcus epidermidis (S. epidermidis) are one of bacterial strains in the human sweats. Staphylococcus bacteria may ferment the glycerol or lactic acid to form short- chain (C2-C3) volatile fatty acids (VFAs), acetic and propionic acids. Additionally, the bacteria can convert the branched aliphatic amino acids to the highly odorous short-chain (C4-C5) methylbranched VFAs, like Isovaleric acid. These bacteria metabolize pyruvate, yield αacetolactate as intermediate and subsequently converted α-acetolactate nonenzymatically to diacetyl by oxidative decarboxylation. L-lactate is a major carbon source of S. epidermidis fermentation in sweats to produce diacetyl. We designed a new device for the measurement of diacetyl by connection of S. epidermidis culture to GASTEC TUBES 92L (GT 92L) in the absence or presence of L-lactate. 5-methyl furfural (5-MF) was used as an inhibitor for the production of diacetyl by S. epidermidis L-lactate fermentation. By conducting the maximum bacteriocidal concentration (MBC) test, we found that 0.15% of 5-MF is non-toxic to S. epidermidis as well as CCD 106 KERTr keratinocyte cells. Incubation of S. epidermidis with 5-MF in the presence of L- lactate significantly reduced the production of diacetyl. Our results introduce a novel device for detection of malodour produced by fermentation of human skin commensal bacteria and suggest that 5-MF holds great potential as a compound for development of next-generation deodorants. Keywords: Deodorants, Diacetyl, Fermentation, Methyl furfural, S.epidermidis
