• Food Science of Animal Resources
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• v.28 no.5
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• pp.596-603
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• 2008

Lactobacillus acidophilus is a normal inhabitant of the human intestine and its numerous health benefits have been reported. This organism is referred to as a "starter culture". This study was conducted to verify that the production of flavor compounds in fermented milk was obtained using a good probiotic strain of L. acidophilus from breast-fed infant feces. The bitter-tasting amino acids, such as arginine and histidine were produced in larger amounts than other free amino acids when L. acidophilus strains were inoculated in skim milk. The lactic acid was the major acid produced from glucose. L. acidophilus NB 209 was the best producer of lactic acid. This L. acidophilus NB 209 produced higher amounts of acetaldehyde than other L. acidophilus strains. L. acidophilus NB 209 gave higher flavor and taste score of the yogurt produced than other L. acidophilus strains in sensory evaluation. These results indicate that L. acidophilus NB 209 has the potential to be developed as a starter culture for fermented milk products.

• Food Science of Animal Resources
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• v.25 no.1
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• pp.92-97
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• 2005

This study was carried out to determine the storage, cryotolerance, heat and drying resistance, when Lactobacillus acidophilus CT 01 isolated from preweaned piglet feces growing at suboptimal temperature. L. acidophilus CT 01 suboptimal temperature incubated for 48 hours had the slowest growth rate at 22℃ but the highest viable cell number after 36 hours at 22℃, with 1.3×10/sup 9/ CFU/mL. In case of 4 and 20℃ storage, the suboptimal temperature incubated groups had a viability higher than the control (p<0.01). The cryotolerance of suboptimal temperature incubated L. acidophilus CT 01 was a higher than the control (p<0.01). When L. acidophilus CT 01 was heat treated at 60℃ for 15 minutes and 30 minutes, the suboptimal temperature incubated L. acidophilus CT 01 at 22℃ had a viability higher more than the control (p<0.01). L. acidophilus CT 01 incubated suboptimal temperature was inoculated by 30% to the carrier, and dried at 50℃ for 12 hours had the highest viability in the suboptimal temperature incubated L. acidophilus CT 01 at 28℃.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.12
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• pp.1790-1797
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• 2002

Lactic acid bacteria were isolated from piglets and chicken and characterized. Lactic acid bacteria showing resistance to low pH and bile, adhesion to intestinal epithelium cells, and the inhibition of Escherichia coli and Salmonella spp. were identified as Lactobacillus acidophilus. L. acidophilus PF01 survived for 2 h in MRS broth adjusted to pH 2. L. acidophilus CF07 was less resistant than L. acidophilus PF01 to pH 2, but survived at pH 2.5 for 2 h. Both of isolates were able to grow in MRS broth containing 0.3% (w/v) bile, with L. acidophilus CF07 being more tolerant to bile than L. acidophilus PF01. L. acidophilus PF01 and CF07 adhered specifically to the duodenal and jejunal epithelium cells of piglet, and the cecal and duodenal epithelium cells of chicken, respectively. Both of isolates did not adhere to the epithelium cells of the various animal intestines from which they were isolated. When L. acidophilus was cultured with E. coli and Salmonella spp. in MRS broth, MRS broth containing 2% skim milk powder or modified tryptic soy broth at $37^{\circ}C$, L. acidophilus PF01 and CF07 inhibited the growths of E. coli K88 and K99, and S. enteritidis and S. typhimurium, respectively. Both of isolates were found to possess the essential characteristics of probiotic lactic acid bacteria for piglet and chicken.

• Journal of Animal Science and Technology
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• v.63 no.6
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• pp.1411-1422
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• 2021

Lactobacillus acidophilus is a gram-positive, microaerophilic, and acidophilic bacterial species. L. acidophilus strains in the gastrointestinal tracts of humans and other animals have been profiled, but strains found in the canine gut have not been studied yet. Our study helps in understanding the genetic features of the L. acidophilus C5 strain found in the canine gut, determining its adaptive features evolved to survive in the canine gut environment, and in elucidating its probiotic functions. To examine the canine L. acidophilus C5 genome, we isolated the C5 strain from a Korean dog and sequenced it using PacBio SMRT sequencing technology. A comparative genomic approach was used to assess genetic relationships between C5 and six other strains and study the distinguishing features related to different hosts. We found that most genes in the C5 strain were related to carbohydrate transport and metabolism. The pan-genome of seven L. acidophilus strains contained 2,254 gene families, and the core genome contained 1,726 gene families. The phylogenetic tree of the core genes in the canine L. acidophilus C5 strain was very close to that of two strains (DSM20079 and NCFM) from humans. We identified 30 evolutionarily accelerated genes in the L. acidophilus C5 strain in the ratio of non-synonymous to synonymous substitutions (dN/dS) analysis. Five of these thirty genes were associated with carbohydrate transport and metabolism. This study provides insights into genetic features and adaptations of the L. acidophilus C5 strain to survive the canine intestinal environment. It also suggests that the evolution of the L. acidophilus genome is closely related to the host's evolutionary adaptation process.

• Journal of Microbiology and Biotechnology
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• v.32 no.10
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• pp.1226-1233
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• 2022

Probiotics are live microorganisms that can be consumed by humans in amounts sufficient to offer health-promoting effects. Owing to their various biological functions, probiotics are widely used in biological engineering, industry and agriculture, food safety, and the life and health fields. Lactobacillus acidophilus (L. acidophilus), an important human intestinal probiotic, was originally isolated from the human gastrointestinal tract and its functions have been widely studied ever since it was named in 1900. L. acidophilus has been found to play important roles in many aspects of human health. Due to its good resistance against acid and bile salts, it has broad application prospects in functional, edible probiotic preparations. In this review, we explore the basic characteristics and biological functions of L. acidophilus based on the research progress made thus far worldwide. Various problems to be solved regarding the applications of probiotic products and their future development are also discussed.

• Journal of Microbiology and Biotechnology
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• v.4 no.2
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• pp.151-154
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• 1994

Lactobacillus acidophilus KFRI 233, a strain isolated from human, was selected as a candidate for probiotics due to its excellent growth in MRS broth where no special anaerobic condition is required. Both simultaneous and deferred agar diffusion assays exhibited Lb. acidophilus KFRI 233 to possess an antagonistic effect against Clostridium perfringens. Its antagonistic effect was pH dependent Associative culture of KFRI 233 and Cl. perfringens in broth resulted in maximum 94.04% inhibition of Cl. perfringens. $\beta$-Galactosidase activity of KFRI 233 was higher than other tested strains that are sold as commercial probiotics. Survival of KFRI 233 in pasteurized skim milk (4$^{\circ}C$) and Sherbet mix (-15$^{\circ}C$) after 7 days of storage were 71.9 and 105.5%, respectively.

• Food Science of Animal Resources
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• v.29 no.1
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• pp.15-23
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• 2009

In order to develop a new starter for fermented milk, 2082 bacteria were isolated from raw milk. The strain that showed excellent acid forming and ${\gamma}$-aminobutyric acid (GABA) production ($711.40{\mu}g/g$ D.W) characteristics after incubation at $37^{\circ}C$ for 18 hr was selected and identified as Lactobacillus acidophilus by the result of API carbohydrate fermentation pattern and 16S rDNA sequence. L. acidophilus RMK567 was investigated for its physiological characteristics. RMK67 strain showed good GABA production compared with commercial lactic acid bacteria. The optimum growth temperature of L. acidophilus RMK567 was $40^{\circ}C$ and cultures took 15 hr to reach pH 4.3. L. acidophilus RMK567 showed higher sensitivity to penicillin-G, novobiocin, as compared to other 14 different antibiotics. However, it showed more resistance to kanamycin, neomycin, streptomycin. It showed higher leucine arylamidase and ${\beta}$-galactosidase activities compared to 16 other enzymes. It was comparatively tolerant to bile juice and able to survive at pH 2 for 3 hr. It showed resistence to Escherichia coli, Salmonella typhimurium and Staphylococcus aureus with rates of 29.2%, 39.1% and 51.4%, respectively. Based on these and previous results, L. acidophilus RMK567 could be an excellent starter culture for fermented milk with excellent GABA contents.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1642-1647
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• 1999

Twenty healthy adult volunteers (divided into two groups) were given with 100 mL of acidophilus milk, twice a day, containing $1{\times}10^8\;cfu/mL$ of Lactobacillus acidophilus SNUL 01 or SNUL 02 originated from healthy Korean adults. The floral changes of lactobacilli, Escherichia coli, and Clostridium perfringens surviving in the feces as well as the pH of the fecal material have been studied for three weeks. Initial pH of the fecal samples before taking acidophilus milk were about pH 7 and it has been decreased to about pH 5 when the acidophilus milk was given. Population of fecal lactobacilli increased from about $10^7\;cfu/g\;to\;10^8\;cfu/g$ of fecal material after 4 days of acidophilus milk intake and the high population of lactobacilli was maintained up to 21 days. Viable cells of the fecal E. coli and C. perfringens have been decreased from about $10^7{\sim}10^8\;cfu/g\;and\;10^5{\sim}10^6\;cfu/g\;to\;10^6\;cfu/g\;and\;10^3\;cfu/g$ of fecal material after 21 days, respectively. In conclusion, continuous intake of acidophilus milk made with L. acidophilus SNUL 01 and SNUL 02 helped maintaining normal intestinal microflora, suppress harmful microorganisms.

• Applied Biological Chemistry
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• v.27 no.1
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• pp.7-13
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• 1984

The effects of various nutrients added to soy milk on the growth of Lactobacillus acidophilus were investigated. Soy milk was prepared from defatted soy flour and various nutrients such as sugars, growth stimulating agents, amino acid and milk by-products. The growth curve obtained from the experiment suggested that the log phase ended after 12hr. Glucose and fructose greatly enhanced the acid production by L. acidophilus. The optimum concentration of these two sugars in the media was approximately 3% each. Among the tested growth stimulating agents, yeast extract stimulated the acid production by L. acidophilus, and the optimum concentration of this additive was approximately 0.5%. L-methionine reduced the acid production by L. acidophilus. Whey powder and skim mills powder did not significantly stimulated the growth and acid production by L. acidophilus. Concentration of protein in soy milk did not affect the growth and acid production by L. acidophilus.

• Preventive Nutrition and Food Science
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• v.10 no.4
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• pp.333-339
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• 2005

Three lactobacillus strains, two from infant feces, and one from cow's milk, were selected among 172 isolates, from multiple sources, for further study based on the antimicrobial activities against six strains of pathogenic bacteria and identified as Lactobacillus acidophilus. The strains revealed a wide scope of spectrum against pathogenic bacteria. Viable Lactobacillus acidophilus KH-l cell counts at pH 2.0 were slightly decreased to $1.42\times10^7$ CFU/mL from $4.18\times10^7$ CFU/mL, while remaining at $3.42\times10^7$ CFU/mL at pH 4.0 with the survival rate of $33.97\%\;and\;81.82\%$, respectively. At the concentration of $0.1\%$ oxgall, L acidophilus KH-l kept growing up to $3.12\times10^7$ CFU/mL with a mean growth rate constant (k) of 0.25, and cell number was slightly decreased to $1.21\times10^7$ CFU/mL (k=0.19) with $0.3\%$ oxgall, but remained at $7.6\times10^6$ CFU/mL (k=0.17) with $0.5\%$ oxgall. L. acidophilus KH-l had a $D_{60}$ value of 7.14, with viable cell numbers $1.4\times10^5$ CFU/mL after heat treatment at $60^{\circ}C$ for 30 minutes. Stability of L acidophilus KH-l at $-20^{\circ}C$ was significantly higher, when the strain was cultivated under the optimum growth temperature $(54.41\%\;and\;54.35\%)$ than at the temperature $(13.53\%)$.