A polyphasic molecular approach was used in order to characterize and taxonomically assign Debaryomyces yeast isolates of different origins. Actin 1 (ACT1) gene sequences coupled with AFLP markers showed that the investigated yeasts belonged to the recently reinstated species D. hansenii, D. fabryi and D. tyrocola. The strain HA1179 was supposed to be a D. hansenii strain with introgressed D. fabryi DNA segments. This strain acquired ribosomal RNA encoding genes (rDNA) and the ACT1 gene from the species D. fabryi and D. hansenii respectively. Comparative sequence analysis of the ACT1 gene, ITS1-5.8S-ITS2 (5.8S-ITSs) and D1/D2 regions, suggested that five strains isolated from a municipal wastewater treatment plant could represent a new taxon of the genus, for which the name Debaryomyces vindobonensis was proposed. The calculated degree of similarity between the AFLP patterns indicated that the strains of D. vindobonensis and the closely related species were separated by the values ＜0.5. New yeast isolates showed very similar morphological and physiological properties to related Debaryomyces species. They differed notably only by the assimilation of rhamnose and growth at 50% glucose. In contrast to the other species, D. vindobonensis was unable to assimilate starch.

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　Fermented dairy products have been consumed widely by our society as a part of their daily meal. Nowadays, because of the high awareness of people about health in relation to food consumption, demand on fermented dairy products which are not only affordable, delicious, and fulfil the nutritious requirement, but also beneficial for our health are gaining attention. Traditionally, there are many fermented milk products produced in some area in the world and have been believed to confer beneficial effect to host. However, because the fermentation processes occur naturally, the quality of the products is not always stable. Several studies have been done to isolate and characterize the indigenous starter microorganisms from several traditional dairy products, for example some endogenous lactic acid bacteria from traditional fermented milk or moulds from fermented cheeses. To exhibit functional effect, starter microorganisms should be well proven to show good physiological effects, not only during fermentation but also when they enter host's body. In this review, biochemical studies on probiotic properties of endogenous Lactobacillus rhamnosus strains isolated from fermented Sumbawa mare's milk (FSMM) and also characterization of several non-commercial Penicillium strains as mould-ripened cheeses starter will be discussed.

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輸入及び国産ナチュラルチーズより分離したPenicillium roqueforti は, 2%酵母エキス-50%ショ糖液体培地 (YES) にて供試37菌株中16菌株にマイコフェノール酸の生産性を認めた. 供試37菌株のうち, 14℃培養でロックフォール由来5菌株 (14.7～55.0μg/mL) 及びダナブルー由来2菌株 (5.3, 17.7μg/mL) にマイコフェノール生産能を認め, 培養温度14℃の方が25℃より高生産量であった. 国産青かびチーズ由来菌では10菌株中9菌株に4.1～12.2μg/mLのマイコフェノール酸生産能があった. 一方, P. camemberti はYES培地25℃培養で供試20菌株中すべての菌株に痕跡量～6.09μg/mLのサイクロピアゾン酸の生産能がみられ, 培養温度14℃の方が25℃よりも低生産量であった.

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　本研究は，カビ熟成型チーズのスターターとしての特徴づけを目的とし，非商業用Penicillium roqueforti K10株およびR26株，ならびにPenicillium caseicolum DL102株のタンパク質分解活性および脂質分解活性を評価した。また，各菌株を個別に接種したカードスラリー培地を用い，pHの経時変化，揮発性香気成分，アミノ酸組成，ペプチド成分および食品に見出される典型的なカビ毒について明らかにした。その結果，対照として用いた商業用Penicillium roqueforti CB2株ならびにPenicillium camemberti PCTT033株と比較して，K10株とR26株は低い最大pH値を，DL102株はpH値の緩やかな経時変化を示した。これは，カードスラリー培地中において非商業用ペニシリウム属3菌株が商業用2菌株と比較して有意に低いプロテアーゼ活性を示すことを反映していた。カードスラリー培地中の総遊離アミノ酸量は，CB2株と比較してK10株は33%，R26株は39%であり，PCTT033株と比較してDL102株は99%であった。非商業用Penicillium属3菌株の脂質分解活性は，商業用Penicillium属2菌株と比較して有意に低かった。揮発性香気成分の種類はK10株，R26株，CB2株間で同じであったが，DL102株はPCTT033株と比較して少なかった。非商業用Penicillium属3菌株を摂取したカードスラリー培地中に数種類の生理活性ペプチドを検出した。いずれの非商業用Penicillium属菌株もカビ毒は検出限界以下であり，その安全性が示唆された。以上から，非商業用Penicillium属菌株K10株，R26株，CB2株は，カビ熟成型チーズのスターターとして高い利用可能性が示されたが，それらの産業利用には実用面でのさらなる調査研究が必要である。

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