• 한국생물공학회:학술대회논문집
• /
• 2005.04a
• /
• pp.181-185
• /
• 2005

We investigated the fermentative production of lactic acid from cheese whey and corn steep liquor as cheap raw materials using Lactobacillus sp. RKY2 to reduce the manufacturing cost of lactic acid. Lactic acid yields were obtained at more than 0.98 g/g from medium containing whey lactose. Lactic aid productivities and yields obtained from whey lactose were slightly higher than those obtained from pure lactose. The final concentration of lactic acid increased with increase, in whey lactose concentration, whereas the lactic acid productivity decreased probably due to substrate inhibition. The fermentation efficiencies were improved by addition of more corn steep liquor to the medium.

• Microbiology and Biotechnology Letters
• /
• v.43 no.3
• /
• pp.286-290
• /
• 2015

Lactic acid is a useful platform chemical for a wide range of food and industrial applications such as pharmaceuticals and cosmetics. Among 313 strains of lactic acid bacteria isolated from different traditional Korean fermented foods, eight Lactobacillus strains effectively utilized xylose as a carbon source to produce lactic acid. A lactic acid bacterium identified as Lactobacillus buchneri produced the highest amount of lactic acid from xylose under anaerobic conditions. The optimum xylose concentration and incubation temperature were 50 g/l and 37℃, respectively; under these conditions, 22.3 g/l lactic acid was produced.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.9 no.4
• /
• pp.303-308
• /
• 2004

We isolated a novel lactic acid bacterium from a Korean traditional fermented food, soybean paste. The newly isolated strain, dubbed RKY2, grew well on glucose, sucrose, galactose, and fructose, but it could not utilize xylose, starch, or glycerol. When the partially amplified 16S rDNA sequence (772 bp) of the strain RKY2 was compared with 10 reference strains, it was found to be most similar to Lactobacillus pentosus JCM $1588^T$, with 99.74% similarity. There-fore, the strain RKY2 was renamed Lactobacillus sp. RKY2, which has been deposited in the Korean Collection for Type Cultures as KCTC 10353BP. Lactobacillus sp. RKY2 was found to be a homofermentative lactic acid bacterium, because its end-product from glucose metabolism was found to be mainly lactic acid. It could produce more than 90 g/L of lactic acid from MRS medium supplemented with 100 g/L of glucose, with 5.2 g $L^-1$ $h^-1$ of productivity and 0.95 g/g of lactic acid yield.

• Journal of Microbiology and Biotechnology
• /
• v.25 no.1
• /
• pp.26-32
• /
• 2015

Four types of straw, namely, soybean, wheat, corn, and rice, were investigated for use in lactic acid production. These straws were mainly composed of cellulose, hemicellulose, and lignin. After pretreatment with ammonia, the cellulose content increased, whereas the hemicellulose and lignin contents decreased. Analytical results also showed that the liquid enzymatic hydrolysates were primarily composed of glucose, xylose, and cellobiose. Preliminary experiments showed that a higher lactic acid concentration could be obtained from the wheat and soybean straw. However, soybean straw was chosen as the substrate for lactic acid production owing to its high protein content. The maximum lactic acid yield (0.8 g/g) and lactic acid productivity (0.61 g/(l/h)) were obtained with an initial reducing sugar concentration of 35 g/l at 30℃ when using Lactobacillus casei (10% inoculum) for a 42 h fermentation period. Thus, the experimental results demonstrated the feasibility of using a soybean straw enzymatic hydrolysate as a substrate for lactic acid production.

• Archives of Pharmacal Research
• /
• v.28 no.3
• /
• pp.325-329
• /
• 2005

The hepatoprotective activity of lactic acid bacteria (Lactobacillus brevis HY7401, Lactobacillus acidophilus CSG and Bifidobacterium longum HY8001), which inhibited $\beta$-glucuronidase productivity of intestinal microflora, on t-BHP- or CCl$_4$-induced hepatotoxicity of mice were evaluated. These oral administration of lactic acid bacteria lowered $\beta$-glucuronidase production of intestinal microflora as well as Escherichia coli HGU-3. When lactic acid bacteria at a dose of 0.5 or 2 g (wet weight)/kg was orally administered on CCl$_4$-induced liver injury in mice, these bacteria significantly inhibited the increase of plasma alanine transferase and aspartate transferase activities by $17-57\%$ and $57-66\%$ of the $CCI_4$ control group, respectively. These lactic acid bacteria also showed the potent hepatoprotective effect against t-BHP-induced liver injury in mice. The inhibitory effects of these lactic acid bacteria were more potent than that of dimethyl diphenyl bicarboxylate (DDB), which have been used as a commercial hepatoprotective agent. Among these lactic acid bacteria, L. acidophilus CSG exhibited the most potent hepatoprotective effect. Based on these findings, we insist that an inhibitor of $\beta$-glucuronidase production in intestine, such as lactic acid bacteria, may be hepatoprotective.

• Food Science of Animal Resources
• /
• v.32 no.2
• /
• pp.155-161
• /
• 2012

This study was carried out to investigate the encapsulation of lactic acid in starch matrix for the application into emulsified sausages. For the encapsulation of lactic acid in starch, the extrusion method was applied, by the different extrusion pressure level. The particle size and morphology of lactic acid containing starch granules and the rate of release of lactic acid from those granules were determined by using Mastersizer$^{(R)}$, a scanning electron microscopy, and electrical conductivity. The size varied slightly depending upon the extruder pressure and influenced entrapment efficiency. Lactic acid was released more slowly, when the extruder had fewer holes, which meant higher extrusion pressure, than when the extruder had more holes. Extruder pressure is therefore critical for producing finer granules that can retain lactic acid longer, during the processing of meat products.

• Asian-Australasian Journal of Animal Sciences
• /
• v.18 no.11
• /
• pp.1582-1588
• /
• 2005

This study aimed to evaluate the effects of silage additives on the fermentation qualities and residual mono- and disaccharides composition of silages. Forage Oats (Avena sativa L.) and Italian Ryegrass (Lolium multiflorum Lam.) were ensiled with glucose, sorbic acid and pre-fermented juice of epiphytic lactic acid bacteria (FJLB) treatments for 30 days. In both species grass silages, although the respective controls had higher contents of butyric acid (20.86, 33.45g $kg^{-1}$ DM) and ammonia-N/total nitrogen (100.07, 114.91 g $kg^{-1}$) as compared with other treated silages in forage oats and Italian ryegrass, the fermentation was clearly dominated by lactic acid bacteria. This was well indicated by the low pH value (4.27, 4.38), and high lactic acid/acetic acid (6.53, 5.58) and lactic acid content (61.67, 46.85 g $kg^{-1}$ DM). Glucose addition increased significantly (p<0.05) lactic acid/acetic acid, and significantly (p<0.05) decreased the values of pH and ammonia-N/total nitrogen, and the contents of butyric acid and volatile fatty acids as compared with control, however, there was a slightly but significantly (p<0.05) higher butyric acid and lower residual mono- and di-saccharides as compared with sorbic acid and FJLB additions. Sorbic acid addition showed the lowest ethanol, acetic acid and ammonia-N/total nitrogen, and highest contents of residual fructose, total mono- and di-saccharides and dry matter as well as high lactic acid/acetic acid and lactic acid content. FJLB addition had the lowest pH value and the highest lactic acid content, the most intensive lactic acid fermentation occurring in FJLB treated silages. This resulted in the faster accumulation of lactic acid and faster pH reduction. Sorbic acid and FJLB additions depressed clostridia or other undesirable bacterial fermentation, thus this decreased the water-soluble carbohydrates loss and saved the fermentable substrate for lactic acid fermentation.

• Journal of Animal Science and Technology
• /
• v.51 no.1
• /
• pp.15-24
• /
• 2009

Two experiments were conducted to compare the effects of different organic acids on growth performance and apparent nutrients digestibility in weaned pigs. In both the experiments, 180 pigs were assigned to four treatments with three replicates comprising of 15 pigs in each. Formic acid, ammonium-formate, lactic acid, and acid mixture were added to diets at 0.50% (Exp. 1) and 0.30% (Exp. 2) as dietary treatments for 5 and 6 wk feeding trial, respectively. The acid mixture was prepared by mixing formic acid and lactic acid at 50:50 ratios. To investigate the apparent ileal amino acids digestibility, twelve pigs (3 per treatment) were used and fitted with simple ileo-caecal T-cannula for both experiments. In Exp.1, growth performance was comparable (P>0.05) among pigs fed different organic acids, while acid mixture had higher (P<0.05) weight gain than that of lactic acid in Exp.2. The apparent ileal digestibility of amino acids was highest (P<0.05) in pigs fed acid mixture and lowest (P<0.05) in pigs fed formic acid diets in both experiments. These results indicated that supplementation with acid mixture (formic acid and lactic acid) improved performance and ileal amino acid digestibility in weaned pigs.

• Journal of environmental and Sanitary engineering
• /
• v.19 no.4 s.54
• /
• pp.69-75
• /
• 2004

The inhibitory effect of the food processing agent on growth of Escherichia coli O157:H7, Salmonella Enteritidis, and Listeria monocytogenes was performed with hydrogen peroxide and lactic acid, and combination of hydrogen peroxide and lactic acid. The minimun inhibitory concentration (MIC) of hydrogen peroxide in E coli O157:H7 was 100 ppm at pH 5.0, 6.0, 6.5 and 7.0, while in Listeria monocytogenes 25 ppm at PH 5.5, 6.0 and 50 ppm at PH 6.5, 75ppm at pH 7.0. MIC of lactic acid in E coli O157:H7 was 2500 ppm at pH 5.0, 6.0, 6.5 and 7.0. MIC of lactic acid in S. Enteritidis was 1250 ppm at pH 5.0, 2500 ppm at pH 5.5, 6.0, 5.5 and 7.0, while in L monocytogenes 625 ppm at pH 5.5 and 125 ppm at pH 6.0, 6.5 and 7.0. MIC of combined hydrogen Peroxide and lactic acid in E. coli O157:H7, S. Enteritidis, and L. monocytogenes was 75 ppm of hydrogen peroxide with 2500 ppm of lactic acid at pH 6.5. The correlations between MICs of hydrogen peroxide and lactic acid in E. coli O157:H7, S. Enteritidis and L. monocytogene were obtained through the coefficient of $determination(R^2)$. $R^2$ value were 0.9994, 0.9935 and 0.9283, respectively. The inhibitory effect of hydrogen peroxide and lactic acid in E. coli O157:H7, S. Enteritidis and L. monocytogenes could be confirmed from the result of this experiment. Therefore, it was expected that the food process would increase or maintain by using lactic acid together with hydrogen peroxide.

• The Korean Journal of Community Living Science
• /
• v.21 no.4
• /
• pp.509-515
• /
• 2010

The physicochemical properties of the lactic acid fermented rice flour prepared using ABT-L(mixture of Lactobacillus acidophilus, Bacillus longum, Streptococcus thermophilus) were investigated. The efficiency of deproteinizing of lactic acid fermentated rice was higher than soaking fermented rice. The structural properties of lactic acid fermented rice flour showed slightly decreased inner particle size but maintained regular structural form. Molar mass and molar size after being treated with soaking or lactic acid fermentation were decreased. Amylograms except for pasting temperature of lactic acid fermented rice flours or soaking fermented rice flours were more significantly decreased than the control sample. The ratio of flours passed through 100 mesh and 150 mesh sieves of lactic acid fermented rice flours were higher than soaking fermented rice flours. Lactic acid fermented rice flours being passed through 100 mesh sieves showed finer particle flours than those treated with soaking. These results showed that lactic acid fermentation, which can have a high efficiency on the deproteinizing of rice, contributed to the changes of particle size and its distribution of rice flour.