• The Korean Journal of Food And Nutrition
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• v.10 no.1
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• pp.122-126
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• 1997

Bifidobacteria have been known as beneficial inhabitant of human intestine. Therefore, bifidobacteria began to be noticed as a starter in the manufacture of fermented dairy products. Perhaps the key for effective use of bifidobacteria in commercial dairy products is the maintenance of viability of bifidobacteria during large scale preparation of starter culture and distribution of products. So we tried to obtain the bifidobacteria having suitable characteristics for using as a starter in the manufacture of fermented dairy products. Among bifidobacteria isolated from Korean, E-4 strain showed the highest resistance to oxygen. To know whether the selected strain will be fit for manufacture of fermented dairy products, we also investigated resistance of the selected strain to HCI. The selected strain, E-4, was more resistant to environmental stresses such as oxygen, H2O2 and HCI than Bifidobacterium longum known as resistant strain to environmental stresses. According to carbohydrate fermentation patterns and morphological characteristics, E-4 strain was identified as B. bifidum. In conclusion, the selected strain, E-4, was thought to be fit for manufacture of fermented dairy products.

• Journal of Plant Biotechnology
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• v.30 no.2
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• pp.135-141
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• 2003

Peroxiredoxin(Pix) are large family of peroxidases that reduce alkyl hydroperoxides and hydrogen peroxide. A cDNA clone (referred to as swPrxl) encoding Pix was from a sweetpotato cDNA library constructed from suspension-sultured cells, and its expression was investigated in terms of stress. The swPrxl contained an open reading frame (ORF) encoding mature protein of 193 amino acids with calculated molecular mass of 20.8kDa. The predicted amino acid sequence of swPrxl has two conserved cysteines that are essential resicues for the reduction of peroxides. It showed high amino acid sequence homology ot PixIIF of Arabidopsis (77%) and putative Prx of rice(72%). RNA gel-blot analysis showed that swPrxl gene was expressed dominantly in leave among intact tissues, and also highly detect in suspension-cultured cells. Interestingly, the level of swPrxl transcripts was almost the same regardless of the growth stage in suspension culture. Furthermore, the transcription level of swPrxl gene was not significantly changed in response to various stress treatments such as wounding, extreme temperature and stress-related chemicals RT-PCR analyses.