• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.1
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• pp.23-28
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• 2005

Lactic acid is a green chemical that can be used as a raw material for biodegradable polymer. To produce lactic acid through microbial fermentation, we previously screened a novel lactic acid bacterium. In this work, we optimized lactic acid fermentation using a newly isolated and homofermentative lactic acid bacterium. The optimum medium components were found to be glucose, yeast extract, $(NH_4)_{2}HPO_4,\;and\;MnSO_4$. The optimum pH and temperature for a batch culture of Lactobacillus sp. RKY2 was found to be 6.0 and $36^{\circ}C$, respectively. Under the optimized culture conditions, the maximum lactic acid concentration (153.9 g/L) was obtained from 200 g/L of glucose and 15 g/L of yeast extract, and maximum lactic acid productivity ($6.21\;gL^{-1}h^{-1}$) was obtained from 100 g/L of glucose and 20 g/L of yeast extract. In all cases, the lactic acid yields were found to be above 0.91 g/g. This article provides the optimized conditions for a batch culture of Lactobacillus sp. RKY2, which resulted in highest productivity of lactic acid.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.5
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• pp.522-529
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• 1998

This experiment was conducted to study the effects of lactic acid bacteria (LAB) inoculation either alone or in combination with cell wall degrading enzymes on the fermentation characteristics and chemical compositions of Rhodesgrass silage. Over to 1 kg of fresh Rhodesgrass sample a treatment of inoculant LAB with or without addition of an enzyme of Acremoniumcellulase (A) or Meicelase (M) or a mixture of both enzymes (AM) was applied. The treatments were control untreated, LAB-treated (application rate $1.0{\times}10^5cfu/g$ fresh sample), LAB+A 0.005%, LAB+A 0.01%, LAB+A 0.02%, LAB+M 0.005%, LAB+M 0.01%, LAB+M 0.02 %, LAB+AM 0.005%, LAB+AM 0.01%, and LAB+AM 0.02%. The sample was ensiled into 2-L vinyl bottle silo, with 9 silages of each treatment were made. Three silages of each treatment were incubated at 20, 30 and $40^{\circ}C$ for 2-months of storage period. All silages were well preserved with their fermentation quality has low pH values (3.91-4.26) and high lactic acid concentrations (4.11-9.89 %DM). No differences were found in fermentation quality and chemical composition of the control untreated silage as compared to the LAB-treated silage. Combined treatment of LAB+cellulases improved the fermentation quality of silages measured in terms of lower (p < 0.01) pH values and higher (p < 0.05) lactic concentrations than those of LAB-treated silages. Increasing amount of cellulase addition resulted in decrease (p < 0.05) of pH value and increase (p < 0.05) of lactic acid concentration. LAB + cellulase treatments (all cellulase types) reduced (p < 0.01) NDF, ADF and in vitro dry matter digestibility of silages compared with the control untreated silages. The fermentation quality and the rate of cell wall reduction were higher (p < 0.01) in the silages treated with LAB + cellulase A than in the silages treated with either LAB+cellulase M or LAB + cellulase AM. Incubation temperature of $40^{\circ}C$ was likely to be more appropriate environment for stimulating the fermentation of Rhodesgrass silages than those of 20 and $30^{\circ}C$.

• The Korean Journal of Food And Nutrition
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• v.29 no.2
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• pp.237-245
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• 2016

In this study, the physicochemical and sensory characteristics of low-salt Myungran jeotkal (Alaskan pollock roe) were evaluated after fermentation at $4^{\circ}C$ and $20^{\circ}C$ with or without the addition of deep sea water, salt from deep sea water, and vegetable-origin lactic acid bacteria (Lactobacillus fermentum JS, LBF). When fermented at $20^{\circ}C$, the addition of LBF to Myungran jeotkal resulted in a slow increase in lactic acid content, followed by an abrupt increase after five days of fermentation. However, when fermented at $4^{\circ}C$, the lactic acid content did not change significantly. Further, when Myungran jeotkal fermented at $4^{\circ}C$, the pH decreased as lactic acid production increased. The salinity of Myungran jeotkal fermented at $4^{\circ}C$ and $20^{\circ}C$ was 7% and was not affected by fermentation period. When fermented at $20^{\circ}C$, volatile basic nitrogen and amino nitrogen contents increased with increasing duration of fermentation. Further, volatile acid content decreased, however, the content of amino nitrogen increased after 11 days of fermentation with LBF and no salt effects were observed. When fermented at $20^{\circ}C$ for 13 days, preference (sensory evaluation) was the highest in all experimental groups after 9 days of fermentation, and then decreased as the fermentation period increased. The free amino acid content was highest (1,648.8 mg/100 g) in Myungran jeotkal when sun-dried salt and LBF were added, 2.3 times higher than in the control.

• Korean journal of food and cookery science
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• v.31 no.6
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• pp.773-780
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• 2015

Lactic acid fermentation of black raspberry (Rubus occidentalis) juice was carried out by using the Lactobacillus plantarum GBL17 strain. The sterilized black raspberry juice was fermented using the L. plantarum GBL17 strain at $30^{\circ}C$ for 72 hours after which the total acidity increased and the pH value decreased. In addition, the highest total acidity content (2.38%) was reached, the lowest pH value (3.22) was observed, and the sugar content decreased by $9.8^{\circ}Brix$ after the 72 hour fermentation. The number of viable cells rapidly increased up until 24 hours, after which it gradually decreased. HPLC analysis of the organic acids showed 14.51 mg/g of lactic acid content in the fermented black raspberry juice, which was not detected in the non-fermented black raspberry juice (control). The content of fructose and glucose slightly decreased after fermentation. The total polyphenol and flavonoid contents of the fermented black raspberry juice increased significantly after fermentation. The DPPH radical scavenging activity of fermented black raspberry juice (70.92%) was higher than that of the control (62.96%). After lactic acid fermentation, there was no significant increase in ABTS radical scavenging activity. These results confirm that lactic acid bacteria, such as L. plantarum GBL17, showed generally higher activities with a potential as a functional beverage.

• Journal of the Korea Organic Resources Recycling Association
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• v.26 no.1
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• pp.47-53
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• 2018

Recovery of lactic acid from fermentation broth using chemical precipitation was investigated with various chemicals. Effects of chemical types, mixing speeds, settling duration, and solvent addition were evaluated to improve the recovery rates of lactic acid. Overall, recovery efficiencies increased as the dosage of chemicals increased. Recovery rate of lactic acid by CaO was higher than those of $Ca(OH)_2$ and $CaCO_3$. Recovery of lactic acid increased by 48% under the optimized reaction conditions which included a mixing speed at 180 rpm, a settling duration of 24 h, and addition of ethanol at 25%(v/v). Practical application needs to consider types and concentrations of other organic acids as well as lactic acid. Based upon the results of fluorescence excitation emission matrix (FEEM), size exclusion chromatography (SEC), characteristics of recovered lactic acid were same as that in the fermentation broth.

• KSBB Journal
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• v.30 no.4
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• pp.161-165
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• 2015

Lactic acid and its derivatives are widely used in the food, pharmaceutical, and cosmetic industries. It is also a major raw material for the production of poly-lactic acid (PLA), a biodegradable and environmentally friendly polymer and a possible alternative to synthetic plastics derived from petroleum. For PLA production by new strains of lactic acid bacteria (LAB), we screened LAB isolates from shellfish. A total of 51 LAB were isolated from 7 types of shellfishes. Lactic acid production of individual isolates was examined using high-performance liquid chromatography using a Chiralpak MA column and an ultraviolet detector. Lactobacillus plantarum T-3 was selected as the most stress-resistant strain, with minimal inhibition concentrations of 1.2 M NaCl, 15% ethanol, and 0.0020% hydrogen peroxide. In a 1 L fermentation experiment, $\small{D}$-lactic acid production of 19.91 g/L fermentation broth was achieved after 9 h cultivation, whereas the maximum production of total lactic acid was 41.37 g/L at 24 h.

• Korean Journal of Food Science and Technology
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• v.40 no.6
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• pp.649-655
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• 2008

In this study, the characteristics of the lactic fermentation of gamju manufactured using a medicinal herb decoction were assessed. A bacterial strain, LAB19, which is used for the induction of lactic fermentation into gamju, was isolated from dried persimmon and identified as Leuconostoc mesenteroides on the basis of morphological, physiological, and chemotaxonomical features, and 16S rRNA sequencing analysis. After 60 hours of lactic fermentation with Leuconostoc mesenteroides LAB19 at $25^{\circ}C$, the gamju was determined to contain 141.3 g/L of reducing sugar, 5.33 g/L of acids, and 1.19 g/L of soluble phenolics. Approximately 90% of reducing sugar and 58% of acids were maltose and lactic acid, respectively. Free radical scavenging activities were retained at levels between 76.6 to 75.7% during the lactic fermentation of gamju.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.4
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• pp.525-530
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• 1999

Prior to ensiling Rhodesgrass (RG) and Italian ryegrass (lRG) were treated with lactic acid bacteria (LAB) or with LAB+cellulases to compare their fermentation characteristics and chemical compositions. LAB (Lactobacillus casei) was added to all ensiling materials (except the untreated control) of RG and IRG at a concentration of $1.0{\times}10^5\;cfu.g^{-1}$ fresh forage. The enzymes used were Acremoniumcellulase (A), Meicelase (M) or a mixture of both (AM). Each enzyme was applied at levels of 0.005, 0.01 and 0.02 % of fresh forage. The silages with each treatment were incubated at 20, 30 and $40^{\circ}C$ and stored for about 2 months. While no marked differences were found between the RG and IRG silages with various treatments on dry matter (DM), volatile basic nitrogen (VBN) and water soluble carbohydrate (WSC) contents, there were significant differences in pH value, and lactic acid and butyric acid contents. LAB inoculation did not affect the fermentation characteristics of either the RG or IRG silages. The combined treatments of LAB+cellulases improved the fermentation quality of both the RG and IRG silages as evidenced by the decrease in pH value and increase in lactic acid content. Increasing the amount of added cellulase resulted in a decrease in pH value and an increase in lactic acid content in both the RG and IRG silages. Cellulases A and AM had a greater effect than cellulase M on the fermentation quality of the RG and IRG silages. Incubation temperatures of 30 and $40^{\circ}C$ appeared to be more appropriate environments for stimulating good fermentation than $20^{\circ}C$.

• Journal of Environmental Health Sciences
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• v.34 no.1
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• pp.70-75
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• 2008

The Chinese cabbage kimchi, baechoo-kimchi, is the most popular type of kimchi in Korea. This study was performed to investigate the changes of index microorganisms (aerobic bacteria, psychrotrophilic bacteria, coliforms, and Escherichia coli), lactic acid bacteria, pH, and acidity of kimchi during the long-term fermentation and ripening. A homemade-style traditional Korean baechoo-kimchi, was prepared from Chinese cabbage, red pepper, green onion, garlic, ginger, and salt-fermented anchovy sauce, and then incubated at $10^{\circ}C$ for 28 days. In the baechoo-kimchi, the number of aerobic bacteria increased with time. The number of psychrotrophilic bacteria maintained their numbers $(10^4CFU/g)$ in the kimchi during the fermentation. Coliforms and E. coli were not detected in the kimchi. The pH of kimchi decreased and the acidity of kimchi increased over time. Lactic acid bacteria, which are representative of fermentative microorganisms in the kimchi process showed rapid growth in the earlier stage of fermentation and increased steadily after 7 days. The counts of lactic acid bacteria were at a level of $10^4CFU/g$ early in the fermentation stage, reaching a level of $10^8CFU/g$ after 14 days, and at this point pH was 4.18 and acidity reached 0.63, indicating that the optimal state of kimchi fermentation. This study suggests that the lactic acid bacteria which were proliferated in kimchi during the ripening and fermentation could contribute to improving the taste and flavor of kimchi and inhibit the growth of pathogenic microorganisms that might exist in kimchi.

• Korean Journal of Medicinal Crop Science
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• v.18 no.6
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• pp.429-438
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• 2010

The use of cellulolytic lactic acid bacteria in new method to prepare high nutrition complementary foods was investigated. For the screening of cellulolytic lactic acid bacteria, more than 1,150 bacterial colony were isolated from diluted infant feces samples. A typical strain which appeared the most excellent cellulolytic activities was identified novel acidophilic Enterococcus sp. TO-94 through the results of morphological, biochemical and chemotaxonomic characteristics and 16S rDNA sequencing. The optimal lactic acid fermentation conditions of Omija(Schizandra chinensis Baillon) by Enterococcus sp. TO-94 were as follows: pH and temperature were 3.0 and $37^{\circ}C$, respectively, and fermentation time was 20hrs. The fructose and glucose were major free sugar and the contents were 5.83 and 4.30 mg/g after fermentation, respectively. The contents of lactic acid and acetic acid were 9.84 mg/g and 2.08 mg/g after fermentation, respectively. The vitamin $B_1$, $B_2$, niacin, folic acid and C were major vitamin in the fermented broth, the contents were 1.5~3 times higher than those of initial fermentation time. Also, the contents of polyphenol and anthocyanine were 3.8 and 1.2 times higher than those of initial fermentation time.