• Title/Summary/Keyword: L-lactic acid

Search Result 1,644, Processing Time 0.032 seconds

Hydrogen and Organic Acids Production by Fermentation Using Various Anaerobic Bacteria (각종 혐기성 미생물 발효에 의한 유기산 및 수소생산)

  • Kim, Mi-Sun;Yoon, Y.S.;Sim, S.J.;Park, T.H.;Lee, J.K.
    • Journal of Hydrogen and New Energy
    • /
    • v.13 no.4
    • /
    • pp.321-329
    • /
    • 2002
  • Clostridium butyricum, Lactobacillus amylophillus, Lactobacillus amylovorus, Lactobacillus acidophillus, AI-9 produced hydrogen and /or organic acids using glucose, lactose and starch at the anaerobic culture conditions. Cl. butyricum NCIB 9576 evolved 1,700 ml H2/L-culture broth and accumulated butyric acid, acetic acid, propionic acid and ethanol in its culture broth when lactose was used as a carbon source during 24 hrs of fermentation. L. amylovorus ATCC 33620 accumulated lactic and acetic acids and some reducing sugars when starch was used as a carbon source without hydrogen production. Instead of starch as a carbon source, L. amylovorus ATCC 33620 produced lactic acid from algal biomass during fermentation and the acid-heat or freeze-thaw pretreatment of algal biomass accelerate the lactic acid fermentation.

Antibacterial Activity and Probiotic Properties of Lactic Acid Bacteria from Korean Intestine Origin (한국인 장관에서 분리한 유산균의 항균활성 및 프로바이오틱스 특성 연구)

  • Kang, Chang-Ho;Kim, Yong Gyeong;Han, Seul Hwa;Jeong, Yulah;Paek, Nam-Soo
    • KSBB Journal
    • /
    • v.32 no.2
    • /
    • pp.153-159
    • /
    • 2017
  • The purpose of this study was to investigate the probiotic properties of lactic acid bacterial strains isolated from human feces. The properties were tested on the basis of guideline for probiotic selection protocol such as tolerance for acid or bile salt, autoaggregation, antibiotic resistance, and antimicrobial activity. Total 25 lactic acid bacteria were isolated from human feces, and their antibacterial activity was tested against Staphylococcus aureus, Escherichia coli, E. coli O157:H7, Vibrio parahaemolyticus, V. alginolyticus using an agar diffusion assay. Among them, 4 selected strains were identified by analysis of their 16S rRNA, as Lactobacillus rhamnosus MG316, L. acidophilus MG501, L. reuteri MG505, and L. gasseri MG570. Results show that resistance to low pH and bile salts. Also, the selected strains were resistant to bile acid up to 3% and their autoaggregation rates were as high as 60%. All strains tested were resistance to nalidixic acid and kanamycin.

Synthesis and Properties of Multiblock Copolymers Consisting of Oligo(L-lactic acid) and Poly(oxyethylene-co-oxypropylene) with Different Composition

  • Lee, Chan-Woo
    • Macromolecular Research
    • /
    • v.9 no.5
    • /
    • pp.259-266
    • /
    • 2001
  • Multiblock copolymer was synthesized by the copolycondensation of oligo(L-lactic acid) prepared by thermal dehydration of L-lactic acid, Pluronic$\^$TM/(PN) and dodecanedioic acid as carboxyl/hydroxyl adjusting agent. This polycondensation proceeded by catalysis of stannous oxide to give the multiblock copolymers with high molecular weight and wide range of compositions. Polymer film was prepared by casting the chloroform solution of the multiblock copolymers having different composition. The multiblock copolymers having relatively high contents of poly(L-lactide) were melt spun into filaments which were subsequently drawn at 60$^{\circ}C$. The copolymer films and the filaments showed an improved flexibility due to the incorporation of the soft segments.

  • PDF

Antifungal Activity of Lactic Acid Bacteria Isolated from Kimchi Against Aspergillus fumigatus

  • Kim, Jeong-Dong
    • Mycobiology
    • /
    • v.33 no.4
    • /
    • pp.210-214
    • /
    • 2005
  • More than 120 isolates of lactic acid bacteria obtained from Kimchi was screened for antifungal activity against Aspergillus fumigatus. Approximately 10% of the isolates showed inhibitory activity and only 4.16% (five isolates) exhibited strong activity against the indicator fungus A. fumigatus. The five isolates showed a wide rang of antifungal activity against A. flavus, Fusarium moniliforme, Penicillium commune, and Rhizopus oryzae. They were identified by 16S rDNA sequencing as Lactobacillus cruvatus, L. lactis subsp. lactis, L. casei, L. pentosus, and L. sakei. The effect of Lactobacillus on mycelial growth and fungal biomass as well as its ability to produce toxic compounds were determined. The results indicate that the three species, Lactobacillus casei, L. lactis subsp. lactis, and L. pentosus, are active against A. fumigatus.

Effect of Additives on the Fermentation Quality and Residual Mono- and Disaccharides Compositions of Forage Oats (Avena sativa L.) and Italian Ryegrass (Lolium multiflorum Lam.) Silages

  • Shao, Tao;Shimojo, M.;Wang, T.;Masuda, Y.
    • 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.

Characterization and Anti-Helicobactor pylori Activity of Xanthium strumarium L. Extract on Lactic acid Fermentation (도꼬마리 추출물의 유산발효 특성 및 Helicobactor pylori에 대한 항균활성)

  • Kang, Dong-Hee;Kim, Hyun-Soo
    • KSBB Journal
    • /
    • v.25 no.3
    • /
    • pp.244-250
    • /
    • 2010
  • This study characterized the anti-Helicobactor pylori activity of Xanthium strumarium L. extract obtained by lactic acid fermentation. The growth of the Lactobacillus strains was typically robust upon lactic acid production in monocultures containing Xanthium strumarium L. extract. Lactic acid fermentation in mixed cultures of Lactobacillus brevis KCTC 3498 and Lactobacillus casei KCTC 3109 produced higher of anti- H. pylori activity than monocultures. Concerning antioxidant activity of fermented extracts, total polyphenol contents were the highest in co-cultures of Lactobacillus brevis KCTC 3498 and Lactobacillus helveticus KCTC 3545. Electron donating ability using diphenyl picryl hydrazyl (DPPH) showed 70% scavenging in Lactobacillus casei KCTC 3109.

Anti-thrombogenicity and Surface Structure of a Poly(ester-ether) Consisting of Poly(L-lactic acid) and Poly(oxyethylene-co-oxypropylene) (Poly(L-lactic acid)와 Poly(oxyethylene-co-oxypropylene)을 포함한 생분해성 Poly(ester-ether)형 블록 공중합체의 항혈전성과 표면구조)

  • 이찬우;문성일;홍영기
    • Polymer(Korea)
    • /
    • v.25 no.3
    • /
    • pp.385-390
    • /
    • 2001
  • The A-B-A type block copoly(ester-ether)s consisting of poly(L-lactic acid) (PLLA)(A) and poly(oxyethylene-co-oxypropylene)(B) were prepared to improve the mechanical properties and hydrolyzability of PLLA. The block copolymers showed an improved flexibility due to the incorporation of the soft segments. Then, the same copolymer has an improved anti-thrombogenicity probably due to the specific microphase separation structure in the surface. The AFM of the film of the block copolymer revealed that the surface was quite flat in comparison with that of PLLA. Therefore, the flatness of the surface may be related with the increased anti-thrombogenicity of the copolymer film.

  • PDF

Synthesis and Characterization of Poly(lactic-co-mandelic acid)s by Direct Solution Polycondensation (직접 용액 축중합에 의한 Poly(lactic acid-co-mandelic acid)의 합성 및 특성 조사)

  • 김완중;김지흥;김수현;김영하
    • Polymer(Korea)
    • /
    • v.24 no.3
    • /
    • pp.431-436
    • /
    • 2000
  • To improve the thermal and mechanical properties of homo poly(L-lactic acid), DL-mandelic acid, one of the natural $\alpha$-hydroxy acid with aromatic ring as the side-chain residue was used as the comonomer. Copolymers with different contents of mandelic acid were prepared and characterized. The resulting copolymers were mostly amorphous. As the amount of mandelic acid in the monomer feed increased, the molecular weight of the resulting polymers tended to decrease linearly. T$_{g}$ and T$_{d}$ of the copolymer, however, were found to shift toward higher temperature, suggesting the improved thermal stability by increasing content of mandelic acid moiety. Tensile measurements of cast films showed somewhat improved values in the copolymers with mandelic acid content of 5 and 10 wt%.%.%.

  • PDF

Effect of Acid Treatment Process on the Physicochemical Properties of Gelatin Extracted from Pork Skin (산처리 공정에 따라 추출한 돈피 젤라틴의 이화학적 특성에 관한 연구)

  • Yeom Geun-Woong;J Andrieu;Min Sang-Gi
    • Food Science of Animal Resources
    • /
    • v.24 no.3
    • /
    • pp.266-272
    • /
    • 2004
  • The objective of this study was to investigate the physicochemical characteristics of gelatin extracted from pork skin under soaking in various acid solutions (lactic acid, acetic acid, and citric acid). Gelatin sol was extracted at 8$0^{\circ}C$, frozen at -2$0^{\circ}C$ and lyophilized it for 3 days to be completely dried in freeze drying unit. In the evaluation of gelatin quality, gelatin soaked in citric acid showed higher L- and a-values than those of any other gelatin (p<0.05). Gelatin treated by acetic acid showed the highest gel strength, cohesiveness, and brittleness. The content of hydroxyproline amino acid in gelatin treated by acetic acid was larger than one of gelatin treated in lactic and citric acid in order. From the experimental results, the highest quality of gelatin in all of period, which was soaked in acetic acid and lactic acid, has a more good quality than gelatin soaked in citric acid.

Microbiological, PH and Sensory Evaluations of Refrigerated Pork Loins Treated with Lactococcus lactis ATCC l1454 (Lactococcus lactis ATCC 11454로 처리한 냉장 돼지고기 등심의 미생물, pH 및 관능평가)

  • 김창렬;김광현;이재일
    • The Korean Journal of Food And Nutrition
    • /
    • v.14 no.2
    • /
    • pp.126-131
    • /
    • 2001
  • Microbiological, pH and sensory evaluations of pork loins treated with lactic acid cultures (Lactococcus lactis subsp. lactis ATCC 11454 grown in 10% milk solids) during storage at 4$^{\circ}C$ were assessed. Pork loins were immersed in solutions containing 3.96 log units, 4.10 log units, or 4.23 log units of individual lactic acid cultures for 2 min. Pork loins treated with lactic acid cultures had a inhibitory effect (P<0.05) on the growth of aerobic palate counts during storage of 3 days at 4$^{\circ}C$. Pork loins treated with lactic acid cultures during storage of 3 days at 4$^{\circ}C$ significantly (P<0.05) decreased pH values compared to those of controls. Sensory evaluations for odor and appearance of pork loins treated with lactic acid cultures during storage of 9 days at 4$^{\circ}C$ were a "liked less" to "typical" category compared to those of controls.

  • PDF