• Journal of Microbiology and Biotechnology
• /
• 제12권5호
• /
• pp.716-721
• /
• 2002

The ldhL gene encoding the $_L$-(+) lactate dehydrogenase was cloned from Lactobacillus reuteri ATCC 55739 chromosomal DNA and characterized. An internal 750-bp fiagment of ldhL gene was amplified by PCR using primers based on the conserved region of lactobacilli ldhL genes. A genomic library off. reuteri ATCC 55739 was constructed using pBR322, and colony hybridization experiments were performed using the 750-bp fragment as aprobe. One clone harboring a 4.0-kb PstI fragment was identified, and nucleotide sequencing confirmed it as an open reading frame of 972 bp in size in the middle. In addition to IdhL gene, an ORF homologous to Streptococcus pneumoniae TIGR4 hydrolase gene and 3' part of phosphomevalonate kinase gene (mvaK2) were also found on the 4 kb fragment. $_L$-LDH of L. reuteri ATCC 55739 showed the highest degree of homology with the $_L$-LDH of Pediococcus acidilactici (62.4%), fullowed by the $_L$-LDH of Lactobacillus pentosus (58.7%). The size of IdhL transcript determined by Northern blot was 1 kb, indicating the monocistronic nature of IdhL.

• Food Science and Biotechnology
• /
• 제15권5호
• /
• pp.677-682
• /
• 2006

Strain HY701 was isolated from human feces for probiotic use by selecting highly resistant isolates to artificial gastric acid and bile acid. Strain HY701 was identified as Lactobacillus reuteri using 16S rDNA sequencing, and tentatively named L. reuteri HY701. The resistance of L. reuteri HY701 to artificial gastric acid (PH 2.5) was high with a survival rate of over 90%. L. reuteri HY701 also showed high tolerance to artificial bile acid after incubation in artificial gastric acid. Using the API ZYM test kit, the carcinogenic enzymes (${\beta}$-glucuronidase and (${\beta}$-glucosidase were not detected with L. reuteri HY70l, while the beneficial enzyme (${\beta}$-galactosidase was weakly detected. L. reuteri HY701 was sensitive to $100\;{\mu}g/mL$ nisin, $20\;{\mu}g/mL$ roxithromycin, $15\;{\mu}g/mL$ erythromycin, but resistant to $20\;{\mu}g/mL$ streptomycin, $10\;{\mu}g/mL$ tetracycline, $20\;{\mu}g/mL$ ciprofloxacin, $20\;{\mu}g/mL$ nystatin, $20\;{\mu}g/mL$ gentamycin, $10\;{\mu}g/mL$ doxycycline, $10\;{\mu}g/mL$ chloramphenicol, and $20\;{\mu}g/mL$ ampicillin. L. reuteri HY701 was shown to possess bactericidal activity as it inhibited the growth of Listeria monocytogenes ATCC 19111 and Escherichia coli JM109 completely within 24 hr of incubation. These results indicate that L. reuteri HY701 could be used as a probiotic strain.

• Journal of Microbiology and Biotechnology
• /
• 제20권8호
• /
• pp.1215-1218
• /
• 2010

The recombinant DNA pLR5cat_PSAB, in which pediocin PA-1 structural and immunity genes (pedAB) fused with the promoter and deduced signal sequence of an ${\alpha}$-amylase gene from a bifidobacterial strain were inserted in Escherichia coli-lactobacilli shuttle vector pLR5cat, was transferred to Lactobacillus reuteri KCTC 3679 and the transformant presented bacteriocin activity. The recombinant L. reuteri KCTC 3679 transformed with the shortened pLR5cat(S)_PSAB, where a nonessential region for the lactobacilli replicon was removed, also showed bacteriocin activity. The molecular mass of the secreted pediocin PA-1 from the recombinant bacteria was the same as that of native pediocin PA-1 (~4.6 kDa) from Pediococcus acidilactici K10 on a sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE) gel. In cocultures with Listeria monocytogenes, the recombinant L. reuteri KCTC 3679 effectively reduced the viable cell count of the pathogenic bacterium by a 3 log scale compared with a control where L. monocytogenes was incubated alone.

• Asian-Australasian Journal of Animal Sciences
• /
• 제21권9호
• /
• pp.1324-1329
• /
• 2008

This study was conducted to evaluate the potential of the transformed Lactobacillus reuteri Pg4 (T-Pg4) harboring the ${\beta}$-glucanase gene as a poultry probiotic. The probiotic properties of the T-Pg4 strain were evaluated in vitro by their adherence capability and acid and bile salt tolerance, and were evaluated in vivo by their survival and adhesion in the gastrointestinal tract (GIT) of specific-pathogen-free (SPF) chickens. The results showed that the T-Pg4 strain exhibited resistance to acidic conditions and contact with bile salt, and adhered efficiently to the crop and intestinal epithelial cells of chickens in vitro. The T-Pg4 strain also could survive and colonize the gastrointestinal epithelium of the experimental SPF chickens in vivo. In addition, radial enzyme diffusion was used to demonstrate that the Lactobacillus spp. randomly isolated from the GIT of the SPF chickens fed T-Pg4 possessed ${\beta}$-glucanase secretion capability. These findings have demonstrated that the transformed L. reuteri Pg4 survives transit through the stomach and intestine, and may secrete ${\beta}$-glucanase in the chicken GIT. Therefore, it is suggested that this organism could be used as a multifunctional poultry probiotic.

• 한국가금학회지
• /
• 제31권2호
• /
• pp.85-91
• /
• 2004

본 연구는 사료내 복합생균제의 첨가에 따른 육계의 성장률 및 영양소 소화율에 미치는 영향을 알아보고자 실시하였다. 사양시험은 2일령 Arbor Acre Broiler(♂) 288수를 공시하였고, 사양시험은 5주간 실시하였다. 시험설계는 옥수수-대두박 위주의 사료인 1) 대조구(CON, basal diet), 2) DFM-1(basal diet + 0.2% Enterococcus sp. ＆ Lactobacillur reuteri), 3) DFM-2(basal diet + 0.2% Enterococcus sp. ＆ Lactobacillus plantarum), 4) DFM-3(basal diet + 0.2% Enterococcus sp. ＆ Lactobacillu reuteri ＆ Lactobacillu plantarum), 5) DFM-4(basal diet + 0.2% Enterococcus sp. ＆ Lactobacillus reuteri ＆ Lactobacillus plantarum ＆ Yeast), 6) DFM-5(basal diet + 0.2% Enterococcus sp. ＆Lactobacillus reuteri ＆ Lactobacillus plantarum ＆ Bacillus subtilis)로 6개 처리로 하였다. 처리당 4반복 12수씩 완전임의 배치하였다. 시작 후 1주까지 생균제 처리구에서 증체량과 사료효율 등에서 대조구보다 높은 결과를 보였으나 유의적인 차이는 없었다. 3∼5주의 기간에서는 생균제 첨가구에서 증체량이 대조구에 비해 개선된 효과를 보였으나 유의적인 차이는 없었다. 전 시험기간에 걸친 변화를 보면 생균제를 첨가한 처리구에서 유의적인 차이는 없었으나 대조구보다 증체량이 높은 경향을 보여 육계 사육기간의 초, 중반기에서 후반기로 갈수록 증체량과, 사료섭취량, 사료효율 등에서 대조구에 비해 개선된 결과를 보였다. DFM-3처리구는 DFM-1보다 성장능력이 낮았으며 DFM-2와 유사하였고, 효모와 Bacillus subtilis가 혼합된 DFM-4와 DFM-5처리구는 높은 성장능력을 보였으나 유의적인 차이는 없었으며 특정생균제의 효과도 발견할 수 없었다. 영양소 소화율은 질소 소화율에서 생균제 처리구가 향상되는 경향을 보였으나 통계적인 차이는 없었다. 결론적으로 복합생균제의 첨가가 복합생균제간 또는 생균제 처리구와 대조구간에는 육계의 생산성에 유의적 차이는 없었으나 후기에 있어서 증체량 및 사료효율을 향상시키는 경향이 있었다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제18권3호
• /
• pp.370-374
• /
• 2005

Two experiments were conducted to evaluate the effects of direct-fed microbial supplementation on the growth performance and nutrient digestibility in pigs. In experiment 1, forty eight pigs were used in a 42-d growth assay. There were four pigs per pen and three pens per treatment. Dietary treatments included 1) NC (without antibiotic basal diet), 2) PC (NC diet+0.1% antibiotic, 100 g/kg chlortetracycline), 3) DFM-1 (NC diet+0.2% Lactobacillus reuteri and Lactobacillus salivarius complex) and 4) DFM-2 (NC diet+0.2% Lactobacillus reuteri, Lactobacillus salivarius, Lactobacillus plantarum and Yeast complex). For the overall period, no treatment had significant effects in growth performance. In the nutrition digestibility, the pigs fed DFM diets were improved in DM and N digestibility compared with the pigs fed NC and PC diets but it was not significantly different. In experiment 2, sixty four crossbred pigs were used in a 98-d growth assay. There were four pigs per pen and four pens per treatment. Dietary treatments included 1) HND (high nutrient diet), 2) LND (low nutrient diet), 3) HND+DFM (HND diet+0.2% Lactobacillus reuteri and Lactobacillus plantarum complex) and 4) LND+DFM (LND diet+0.2% Lactobacillus reuteri and Lactobacillus plantarum complex). For overall period of growing phase, the pigs fed LND diets had improved gain/feed (p=0.01) and for overall period in the finishing phase, the pigs fed LND with DFM diets had higher ADG, ADFI and gain/feed than the others but there were no significant differences (p>0.13). In total period of growing-finishing phase, the pigs fed LND diet had higher gain/feed than the pigs fed HND diets (p<0.05). In growing phase, there were not significant differences among the treatments means for DM and N digestibility. However, the pigs fed diets with DFM had improved N digestibility (p<0.02) compared to the pigs fed diets without DFM in finishing phase. In conclusion, DFM slightly improved the growth performance in growing-finishing pigs.

• Journal of Microbiology and Biotechnology
• /
• 제15권6호
• /
• pp.1178-1182
• /
• 2005

Survival of thermotolerant Lactobacillus reuteri KUB-AC5 in $20\%$ (w/v) skim milk was found to be $11.3\%$ after spray drying by using a pilot scale spray dryer with inlet temperature at $170^{\circ}C$ and outlet temperature at $85^{\circ}C$. The ability of dried cell to produce antimicrobial activity was not affected by the spray drying. The model system for predicting viability of spray-dried L. reuteri KUB-AC5 during long-term storage was established, based on the Arrhenius equation, and verified by experimental data, because the viability of cells during storage can be correlated with storage temperature. The viability during storage at $30^{\circ}C$ declined more rapidly than that storage at $4^{\circ}C$.

• 생명과학회지
• /
• 제22권5호
• /
• pp.575-581
• /
• 2012

본 연구는 가축용 생균제로서 이용성이 우수한 $Lactobacillus$ $plantarum$과 $Lactobacillus$ $reuteri$의 대량생산을 위한 경제적 최적 배지조성을 도출하기 위하여 수행되었다. 두 균주의 배양을 위한 배지성분 요인들은 유산균 배지로 알려진 MRS broth를 기준으로 하여, sucrose, glucose, molasses, yeast extract, corn steep liquor, soy peptone, dipotassium phosphate, manganese chloride, magnesium chloride, tween 80, sodium chloride, sodium acetate, ammonium citrate, sodium sulphate 및 ferrous sulphate 등 총 15가지를 선택하였다. 각 배지성분들이 각 균주들의 세포성장에 미치는 요인분석은 20개의 실험으로 구성된 Plackett-Burman design 방법을 이용하여 분석하였다. 그 결과 $L.$ $plantarum$의 성장에 있어서는 sucrose, glucose, molasses, yeast extract, corn steep liquor, soy peptone, sodium acetate, ammonium citrate 등이 긍정적인 효과(positive effect)를 나타내었다. $L.$ $reuteri$의 경우, yeast extract, soy peptone, $K_2PHO_4$, tween 80에서 수준간의 격차가 큰 긍정적인 효과가 나타났다. 두 가지 균주들에서 얻어진 표준화된 통합적 효과의 주 효과를 분석한 결과, sucrose, yeast extract, soy peptone에서 긍정적인 효과가 나타났다. 최종적으로 $L.$ $plantarum$과 $L.$ $reuteri$ 두 균주에 공통적으로 적용할 수 있는 유효 배지 성분들로 sucrose (20.0 g/l), glucose (5.0 g/l), soy peptone (11.0 g/l), yeast extract (5.0 g/l), $K_2PHO_4$ (0.2 g/l), $CH_3COONa$ (2 g/l) 및 $MgCl_2$ (0.02 g/l)를 선택하였다.

• 대한수의학회지
• /
• 제56권1호
• /
• pp.1-7
• /
• 2016

Lactic acid bacteria (LAB) are commonly used as probiotics in poultry. The present study employed in vitro and in vivo methods to select and test LAB isolated from Muscovy duck ceca as potential probiotics. In the in vitro study, 50 LAB were isolated from Muscovy duck ceca and tested for growth inhibition against Salmonella (S.) Enteritidis. Eleven isolates strongly inhibited S. Enteritidis and only 1 isolate (MD5-2) showing the strongest inhibition was selected for identification. This isolate was called as Lactobacillus (L.) reuteri MD5-2. For the in vivo investigation, 90 1-day-old Muscovy ducks were randomly assigned into three groups of 30 animals each (group 1, control; group 2, treated with $10^8$ colony-forming unit (CFU) of L. reuteri MD5-2 orally once on day 1; and group 3, treated with $10^8CFU$ of L. reuteri MD5-2 orally once daily from days 1 to 5). The ducks were housed in three large cages and raised for 50 days, after which body weight, duodenal villus height and crypt depth were measured. Both villus height and villus height to crypt depth ratio were significantly greater in group 3 than in groups 1 and 2. In conclusion, further investigation of L. reuteri MD5-2 as a potential probiotic strain is warranted.

• Journal of Animal Science and Technology
• /
• 제50권4호
• /
• pp.509-518
• /
• 2008

본 연구는 육계 및 산란계 맹장에서 분리하여 유기산 생성 능력, 내산성, 내담즙성 및 성장특성을 토대로 선발된 유산균 6종(Lacto- bacillus reuteri BLA5, Lactobacillus crispatus avibro1, Lactobacillus reuteri avibro2, Lacto- bacillus amylovorus LLA7, Lactobacillus crispatus avihen1, Lactobacillus vaginalis avihen2)의 효소, 항균 활성 및 항생제 감수성을 조사하여 생균제로서의 이용 가치를 구명하고자 실시하였다. 육계 및 산란계 맹장 유래 유산균은 효소 활성에 있어서는 균주마다 차이가 있었으나, 일반적으로 amylase와 lipase 활성이 강한 것으로 나타났고 반면, cellulase 및 protease의 활성은 약한 것으로 나타났다. 유산균 배양액은 병원성 E. coli에 대하여 강한 항균 활성을 보였으며, 주요 억제 요인으로는 유기산 분비에 의한 pH 저하에 의한 것으로 나타났다. 병원성 Salmo- nella에 대해서는 유산균 배양액의 억제성이 약한 것으로 나타났다. 유산균은 치료용 항생제로 이용되는 ampicillin과 amoxicillin에 대해서는 높은 감수성을 보인 반면 사료용 항생제(virginiamycin 및 salinomycin)의 경우 정상적인 첨가 수준에서는 영향을 받지 않았다.