• 한국미생물·생명공학회지
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• 제22권3호
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• pp.309-315
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• 1994

Selective agar media were constructed for the counting of bifidobacteria in dairy produ- cts containing bifidobacteria, lactobacilli and streptococci. This media containing antibiotics inhibited the growth of lactobacilli and streptococci at less than 10$^{5}$ cfu/ml, but had no influence on the recovery of bifidobacteria. In order to inhibit the growth of 10$^{5}$ cfu/ml of lactobacilli and streptoco- cci, the addition of 1.0~2.0 $\mu$g/ml of tetracycline in BL agar medium was needed. When 25 $\mu$g/ml of neomycin and paromomycin were mixed with 1.0 $\mu$g/ml of tetracycline in BL agar medium, it was able to inhibit the growth of 10$^{6}$ cfu/ml of lactobacilli and streptococci but had a little negative effect on the recovery of colonies of bifidobacteria. The results revealed that the BL agar medium containing 1.0 $\mu$g/ml of tetracycline was suitable to count the cell number of bifidobacteria selecti- vely in the presence of a 1 to 10$^{5}$-fold excess of L. casei, L. acidophilus and S. salivarius subsp.thermophilus.

• Journal of Plant Biotechnology
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• 제41권1호
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• pp.50-55
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• 2014

Plant-based vaccines possess some advantages over other types of vaccine biotechnology such as safety, low cost of mass vaccination programs, and wider use of vaccines for medicine. This study was undertaken to develop the transgenic maize as edible vaccine candidates for humans. The immature embryos of HiII genotype were inoculated with A. tumefaciens strain C58C1 containing the binary vectors (V662 or V663). The vectors carrying nptII gene as selection marker and scEDIII (V662) or wCTB-scEDIII (V663) target gene, which code EIII proteins inhibite viral adsorption by cells. In total, 721 maize immature embryos were transformed and twenty-two putative transgenic plants were regenerated after 12 weeks selection regime. Of them, two- and six-plants were proved to be integrated with scEDIII and wCTB-scEDIII genes, respectively, by Southern blot analysis. However, only one plant (V662-29-3864) can express the gene of interest confirmed by Northern blot analysis. These results demonstrated that this plant could be used as a candidated source of the vaccine production.

• Journal of Dairy Science and Biotechnology
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• 제41권4호
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• pp.211-218
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• 2023

This study aimed to identify lactic acid bacteria isolated from eight fermented milk products in Iran. We enumerated Lactobacillus species using De Man-Rogosa-Sharpe (MRS)-maltose and MRS agar with pH adjusted to 5.2, as well as assessment at 37℃ for 48 hr, studied Streptococcus spp. using M17 agar at 43℃ for 24 hr, and assessed Bifidobacterium species using nalidixic acid, paromomycin sulfate, neomycin sulfate, and lithium chloride (BL-NPNL) agar at 37℃ for 48 hr. The total viable Streptococcus spp. cell in fermented milk varied at 4.73-8.83 log CFU/mL. However, Bifidobacterium spp. were not detected in any of the tested samples. Lactobacilli were not detected in four of the eight samples, and viable Lactobacilli cells in the remaining four samples ranged 2.48-3.85 log CFU/mL. The pH of the tested samples ranged 3.53-4.19, and soluble solids (Brix measurement) ranged 7.5%-17.9%. A total of 130 isolates of gram-positive catalase-positive bacteria were characterized at the species level using 16S rRNA sequencing. Sequence analysis identified six species: Streptococcus thermophilus, Lactobacillus delbrueckii subsp. sunkii, Lactobacillus delbrueckii subsp. indicus, Lactiplantibacillus plantarum, Lacticaseibacillus rhamnosus, and Levilactobacillus brevis.

• 한국축산식품학회지
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• 제30권1호
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• pp.154-162
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• 2010

This study was carried out to compare the efficacy and selectivity of TOS and BS media for enumeration of bifidobacteria in commercial fermented milk products. First, bifidobacteria was isolated from 20 fermented milk products, and all isolated bifidobacteria were identified by genomic technology as Bifidobacterium lactis. The two media significantly differed from each other with regard to the recovery of B. lactis, that is, the recovery of this organism was as much as 6 logs lower on BS medium than on TOS. When the concentration of BS solution (mixture of paromomycin sulfate, neomycin, sodium propionate, and lithium chloride) used in BS medium was reduced to 50% (BS50), a relatively high percentage recovery of bifidobacteria from pure cultures was achieved. Susceptibility tests to antibiotics and tests for selective agents for the isolated bifidobacteria and lactic acid bacteria were conducted. The BS solution inhibited some lactic acid bacteria and Bifidobacterium species, while mupirocin (MU) suppressed the growth of all tested lactic acid bacteria but not Bifidobacterium. As compared with BS50 medium, TOS with or without MU showed good bifidobacteria recovery and readily distinguishable colonies; in particular, TOS supplemented with MU had a high selectivity for bifidobacteria. In conclusion, all results suggested that TOS medium with or without MU was found to be suitable for selective enumeration of bifidobacteria from mixed cultures in fermented milk, and better in that capacity than BS medium.

• Journal of Plant Biotechnology
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• 제32권3호
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• pp.161-165
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• 2005

Agrobacterium과 자엽절편의 공동배양으로 박과작물인 오이의 형질전환체를 생산하였다. 오이 배양재료는 "은침"의 자엽절편을 사용하였으며, reporter유전자로서 gus유전자와 선발표지로서 bar 또는 nptII유전자로 각각 제작된 pPTN289와 pPTN290벡터를 GV3101, LBA4404, EHA101에 형질전환하여 공동배양하였다. 형질전환빈도는 Agrobacterium의 종류에 따라 현저한 차이가 있었으며, 특히 사용한 균주중 EHA101에서 0.35%로 가장 높았다. 선발배지에서 형성된 오이 식물체중 제초제 저항성 (12개체)과 paromomycin 저항성 (3개체)을 얻었고, 이들 모두 gus양성반응 나타냈다. Southern분석에 의하여 오이 형질전환체의 genome에 gus유전자가 도입되어 있음을 확인 하였다.

• Journal of Plant Biotechnology
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• 제32권4호
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• pp.257-262
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• 2005

Agrobacterium과 자엽절 공동배양으로 대두 형질전환체를 생산하였다. 멜론 (슈피VIP품종)의 자엽절 절편은 선발 마커로서 bar와 reporter로서 gus유전자가 포함된 pPTN289 또는 선발마커로서 nptII유전자와 reporter로서 gus유전자로 제작된 pPTN290벡터를 LBA4401, GV3101, EHA101에 각각 형질전환하여 공동 배양하였다. 최대 형질전환빈도(0.16%)는 EHA101 (pPTN289)균주로 공동배양한 자엽절 절편을 glufosinate가 첨가된 선발배지에서 얻을 수 있었으며, 최종적으로 glufosinate저항성과 잎 ($T_0$), 화기 ($T_0$), 종자 ($T_1$) 및 유식물체 ($T_1$)에서 GUS양성반응을 나타내는 5개체를 얻었다. Southern분석에 의하여 GUS유전자가 멜론 genomic DNA에 도입되어 있음을 확인하였다.