• Journal of The Korean Society of Grassland and Forage Science
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• v.39 no.3
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• pp.132-140
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• 2019

Fermented total mixed ration (TMR) is a novel feed for ruminants in South Korea. The purpose of this study was to evaluate the effects of lactic acid bacteria (LAB) on the quality of TMR and in vitro ruminal fermentation. Strains of three LAB spp. (Lactobacillus plantarum, L. brevis, L. mucosae) were used in fermentation of TMR. Inoculations with the three LAB spp. lowered pH and increased concentrations of lactic acid, acetic acid, and total organic acid compared to non-LAB inoculated control (only addition of an equivalent amount of water) (p<0.05). Bacterial composition indicated that aerobic bacteria and LAB were higher. However, E. coli were lower in the fermented TMR than those in the control treatment (p<0.05). Among the treatments, L. brevis treatment had the highest concentration of total organic acid without fungus detection. Gas production, pH, and ammonia-nitrogen during ruminal in vitro incubation did not differ throughout incubation. However, ruminal total VFA concentration was higher (p<0.05) in the LAB spp. treatments than the control treatment at 48 hours. Overall, the use of L. brevis as an inoculant for fermentation of high moisture. TMR could inhibit fungi growth and promote lactic fermentation, and enhance digestion in the rumen.

• Korean Chemical Engineering Research
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• v.53 no.1
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• pp.1-5
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• 2015

Lactic acid, the most widely occurring hydroxy-carboxylic acid, has traditionally been used as food, cosmetic, pharmaceutical, and chemical industries. Even though it has tremendous potential for large scale production and use in a wide variety of applications, high cost lactic acid materials are primarily problems. Lactic acid can be obtained on either by fermentation or chemical synthesis. In recent years, the fermentation approach has become more successful because of the increasing market demand for naturally produced lactic acid. Generally, lactic acid was produced from pure starch or from glucose. As an alternative, biomass which is the most abundant renewable resources on earth have been considered for conversion to readily utilizable hydrolysate. In this study, we conducted the fermentation method to produce L(+)-lactic acid production from pretreated hydrolysate was investigated by Lactobacillus rhamnosus ATCC 10863. The hydrolysate was obtained from pretreatment process of biomass using Ammonia percolation process (AP) followed by enzymatic hydrolysis. In order to effectively enhance lactic acid conversion and product yield, controlled medium, temperature, glucose concentration was conducted under pure glucose conditions. The optimum conditions of lactic acid production was investigated and compared with those of hydrolysate.

• Journal of dental hygiene science
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• v.7 no.1
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• pp.21-24
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• 2007

Dental caries is initiated by the acid accumulated in dental plaque. Streptococcus mutans, one of a major causal agents of dental caries, is component of the dental plaque and produces various organic acids such as lactic acid as the end-product of glycolysis. As a consequence, we investigated the acid stress response of S. mutans KCTC 3065 in this study. The addition of lactic acid to the growth media had a concentration-dependent effect on the growth of S. mutans. S. mutans exhibited higher maximum culture OD compared with the more acidic growth pH values. At treatment of centration of 20 mmol/L lactic acid in the mid-log phage, cell growth was reduced to 40% relative to the control. The following results were obtained with the treatment of cells with a concentration of 20 mmol/L lactic acid in the mid-log phage for 2hrs: Analysis of fatty acids extracted from cells showed that growth at a concentration of 20 mmol/L lactic acid resulted in changes in $C_{14:0}$, $C_{16:0}$, $C_{18:0}$ and $C_{18:1}$ fatty acids. Protein profiles investigated by SDS-PAGE showed that approximately 70, 60, 45, 40 and 23 kDa proteins were highly expressed in S. mutans KCTC 3065.

• Archives of Pharmacal Research
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• v.16 no.4
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• pp.312-317
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• 1993

To confirm a new evaluation tedhnique for biodegradability of biopolymer microsphers in vivo condition, magnetic microsphere sytem was adopted for tracing the microspheres injected and lodged in micr. Microsphers of poly(DL-lactic acid), poly(L-alctic acid) and poly(DL-lactide-coglycolide)(PLGA) were prepared by solvent-extraction method and their organ distribution and biodegradation in mice was examined. Magnetic microspheres lodged in mice organs were recollected from the homogenates of mice organs with a constant flow magnetic separation apparatus. Recollected microspheres were observed by scanning electron microscopy and also were assayed for their magnetite ocntent by atomic absorption spectrophotometry to evaluate the biodegradability of polymeric microspheres. This method seems to be practical and simple to estimate the biodegradability of biopolymers over the conventional methods.

• Polymer(Korea)
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• v.24 no.4
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• pp.477-487
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• 2000

A series of poly(L-lactic acid) (PLLA)/poly($\beta$-hydroxynonanoate) (PHN) blend were prepared to study the miscibility and the crystallization behaviors. The thermal behaviors and characterization of PLLA/PHN blends Were studied using differential scanning calorimetry (DSC), XRD and polarizing optical microscopy (POM). The PLLA and PHN are partially miscible in amorphous region. The crystallinity of PLLA increased as the content of PHN increased, and T$_{g}$, T$_{c}$, and T$_{m}$ of PLLA shift as the content of PHN increased. Moreover, the number of PLLA spherulite increased as the content of PHN increased in the POM experiment. Thus, PHN acted as a nucleating agent to PLLA.

• Macromolecular Research
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• v.17 no.9
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• pp.682-687
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• 2009

Nanofibrous membranes of poly(D,L-lactic acid)/chitin blend were prepared by electro spinning for a barrier of guided tissue regeneration. A miscible solution was obtained by the blending chitin-salt complex into 1-methyl-2-pyrrolidone solution of poly(D,L-lactic acid). The properties of the blend were examined for nanofibrous fabrication. The viscosity of the blend solution was increased significantly due to chain entanglement despite the low ratio of chitin to poly(D,L-lactic acid). An interaction between two polymeric compositions was confirmed by Fourier transform infrared spectroscopy. X-ray diffraction detected an appreciably ordered microstructure in the nanofiber of the blend. A membrane of thinner nanofibers was fabricated by electro spinning the chitin blend. The permeability of the membranes was examined using bioactive model compounds.

• Journal of the East Asian Society of Dietary Life
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• v.25 no.1
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• pp.183-192
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• 2015

This study aimed to produce fermented extracts with sugar made from lotus root (LR) and Platycodon grandiflorum (PG), using lactic acid fermentation, and confirmed their physiological and anti-oxidative activities as basic data for manufacturing functional drinks through sensory tests. For the final sugar concentrations, PG showed $48.1^{\circ}brix$ and LR showed $52.0^{\circ}brix$. Sugar concentrations during lactic acid fermentation following dilution of sugar to $12^{\circ}brix$, ranged from $11.5{\sim}12.1^{\circ}brix$ for PG and $11.9{\sim}12.4^{\circ}C$ for LR. During lactic acid fermentation, lactic acid bacteria numbers tended to decrease in both fermented LR and PG extracts with sugar as the fermentation period increased. For DPPH radical scavenging ability, LR was three times higher in control without lactic acid fermentation while PG showed significant increases in L. acidophilus (77%), L. brevis (90%), and L. delbrueckii (177%) during lactic acid fermentation. For total polyphenol content, LR showed a higher concentration than PG, and except for fermented L. delbrueckii extract showing similarity with the control, contents of fermented extracts decreased. In the case of PG, CUPRAC, increased significantly in L. brevis, whereas FRAP, increased significantly in L. delbrueckii with lactic acid fermentation. For reducing power, except for fermentation with L. brevis, all PG showed lower reducing power activities. In the sensory test of fermented LR and PG extracts with sugar, both fermented extracts showed better results with L. brevis or L. delbrueckii than control or those with L. acidophilus in every item. Based on these results, it is highly possible to develop fermented extract drinks with sugar using LR or PG. In particular, lactic acid bacteria such as L. delbrueckii and L. brevis showed generally higher activities with potential as a functional drink.

• Journal of Pharmaceutical Investigation
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• v.26 no.1
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• pp.13-22
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• 1996

Poly(D,L-lactic acid) (PLA) microspheres containing alprazolam(APZ) were prepared by a solvent-emulsion evaporation method and their release patterns were investigated in vitro. Various batches of microspheres with different size and drug content were obtained by changing the ratio of APZ to PLA, PLA concentration in the dispersed phase and stirring rate. Rod-like APZ crystals on microsphere surface, which were released rapidly and could act as a loading dose, were observed with increasing drug content. The release rate was increased with increase in drug contents and decrease in the molecular weight of PLA. The release rate of APZ for long-acting injectable delivery system in vitro, which would aid in predicting in vitro release profile, could be controlled by properly optimizing various factors affecting characteristics of microspheres.

• The Korean Journal of Food And Nutrition
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• v.28 no.6
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• pp.956-964
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• 2015

Probiotics is known improve the microenvironment of colon; however, the metagenomic DNA study of its lactic acid bacteria in constipation induced by loperamide is not clearly understood. In the present study, we investigated the reduction of the lactic acid bacteria in case of constipation, in normal and loperamide-induced rat. Lactic acid powder (lactic acid bacteria 19) was prepared from Chong Kun Dang Pharmaceutical Corporation. After 2 weeks of oral administration, the group treated with the higher concentration of lactic acid bacteria ($10^9CFU/mL$ per kg of body weight) following loperamide treatment was the most effective in increasing number, weight, and water content of feces. A similar but significant increase was found in the group treated with lower concentration of lactic acid bacteria ($10^7CFU/mL$ per kg of body weight) after loperamide treatment. The concentrations of acetic acid and propionic acid in feces in the loperamide-induced rat with high concentration lactic acid, were significantly higher than that of others. Furthermore, gastrointestinal transit ratio as well as the length and area of intestinal mucosa were significantly increased after treatment with lactic acid bacteria in loperamide-induced rat. Metagenomics DNA analysis indicated that the microorganism homology in cecum was similar between the groups of normal (NOR) and HIG. Our results show that lactic acid bacteria were effective in improving the constipation.

• KSBB Journal
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• v.11 no.4
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• pp.389-397
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• 1996

The growth of recombinant E. coli and formation of the by-products were investigated. Ammonium phosphate is known to affect the cell growth as well as the enzyme formation. When initial ammonium phosphate concentration was 0.5g/L, cell mass was 4.1g/L. By adding tryptone to the medium, acetic acid formation increased while lactic acid formation decreased. In cultivating recombinant E. coli, lactic acid and acetic acid turned out to be important by-products which affected cell yield and growth rate. Initial ammonium phosphate and tryptone concentration were optimized in our research and can be applied for other culture of recombinant E. coli.