Gotowe bibliografie tematyczne / Lactic acid

Gotowa bibliografia na temat „Lactic acid”

Autor: Grafiati
Data publikacji: 4 czerwca 2021
Data aktualizacji: 31 lipca 2024

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Artykuły w czasopismach na temat "Lactic acid"

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Orozco, F. G., A. Valadez-González, J. A. Domínguez-Maldonado, F. Zuluaga, L. E. Figueroa-Oyosa i L. M. Alzate-Gaviria. "Lactic Acid Yield Using Different Bacterial Strains, Its Purification, and Polymerization through Ring-Opening Reactions". International Journal of Polymer Science 2014 (2014): 1–7. http://dx.doi.org/10.1155/2014/365310.

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Laboratory-scale anaerobic fermentation was performed to obtain lactic acid from lactose, using five lactic acid bacteria:Lactococcus lactis, Lactobacillus bulgaricus, L. delbrueckii, L. plantarum,andL. delbrueckii lactis. A yield of 0.99 g lactic acid/g lactose was obtained withL. delbrueckii, from which a final concentration of 80.95 g/L aqueous solution was obtained through microfiltration, nanofiltration, and inverse osmosis membranes. The lactic acid was polymerized by means of ring-opening reactions (ROP) to obtain poly-DL-lactic acid (PDLLA), with a viscosity average molecular weight (Mv) of 19,264 g/mol.
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Admanova, G. B., Zh I. Kuanbay, R. Izimova, G. O. Keubassova i L. S. Kozhamzharova. "Some enzymatic properties of lactic acid bacteria isolated from dairy products". Bulletin of the Karaganda University. “Biology, medicine, geography Series” 112, nr 4 (30.12.2023): 7–13. http://dx.doi.org/10.31489/2023bmg4/7-13.

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This article presents data on the study of physiological and biochemical properties, antagonistic and enzymatic activity of lactic acid bacteria isolated from dairy products. 9 types of lactic acid bacteria were studied: Lactobacillus bulgaricus GM – 08, Lactobacillus bulgaricus KZh – 01, actobacillus bulgaricus GS – 03, Lactococcus cremoris – 6, Lactococcus cremoris – 17, Lactococcus cremoris – 26, Lactococcus lactis – 1, Lactococcus lactis – 15, Lactococcus lactis – 23. These strains were found to have resistance to 2% and 4%-vertical NaCl concentrations, bile and phenol. In addition, the antagonistic activity of Gram-positive and Gram-negative microorganisms in relation to test cultures of Staphylococcus aureus, Salmonella dublin,Escherichia coli, Bacillus subtilis, Sarcina flava was studied. All studied lactic acid bacteria showed activity in Test cultures with different inhibition zones. The Lactococcus lactis – 23 strains showed high activity for all cultures, with an inhibition zone of 17-25 mm. Further, 5 strains were selected from these strains and their aroma-forming properties, the formation of diacetyl and ammonia from arginine, hemolytic and lecithinase activity were studied. Compositions were compiled from these strains to make yeast. The compatibility of strains of lactic acid bacteria was checked with each strain individually and with the duration of milk clotting according to organoleptic indicators compared to the duration of milk clotting. Thus, the most active clot formation was obtained by the Lactococcus lactis – 23 strain of the selected combinations.
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RAO, R. D., W. L. WENDORFF i K. SMITH. "Changes in Galactose and Lactic Acid Content of Sweet Whey during Storage". Journal of Food Protection 67, nr 2 (1.02.2004): 403–6. http://dx.doi.org/10.4315/0362-028x-67.2.403.

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Whey is often stored or transported for a period of time prior to processing. During this time period, galactose and lactic acid concentrations may accumulate, reducing the quality of spray-dried whey powders in regard to stickiness and agglomeration. This study surveyed industry samples of Cheddar and mozzarella cheese whey streams to determine how galactose and lactic acid concentrations changed with storage at appropriate (4°C) and abuse (37.8°C) temperatures. Samples stored at 4°C did not exhibit significant increases in levels of lactic acid or galactose. Mozzarella whey accumulated the greatest amount of galactose and lactic acid with storage at 37.8°C. Whey samples derived from cheese made from single strains of starter culture were also evaluated to determine each culture's contribution to galactose and lactic acid production. Starter cultures evaluated included Streptococcus salivarius ssp. thermophilus, Lactobacillus helveticus, Lactobacillus delbrueckii ssp. bulgaricus, Lactococcus lactis ssp. cremoris, and Lactococcus lactis ssp. lactis. Whey derived from L. helveticus accumulated a significantly greater amount of lactic acid upon storage at 37.8°C as compared with the other cultures. Galactose accumulation was significantly decreased in whey from L. lactis ssp. lactis stored at 37.8°C in comparison with the other cultures. Results from this study indicate that proper storage conditions (4°C) for whey prevent accumulation of galactose and lactic acid while the extent of accumulation during storage at 37.8°C varies depending on the culture(s) used in cheese production.
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Al-Saman, Mahmoud Abd El-Hamid, Rafaat M. Elsanhoty i A. E. Elhadary. "The impact of oil type and lactic acid bacteria on conjugated linoleic acid production". Journal of Biochemistry, Microbiology and Biotechnology 4, nr 2 (30.12.2016): 25–29. http://dx.doi.org/10.54987/jobimb.v4i2.306.

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This work was conducted to investigate the effect of oil type and lactic acid bacteria on the conjugated linoleic acid (CLA) production in MRS medium. The ability of eight strains of lactic acids bacteria; Lactobacillus acidophilus (P2, ATCC 20552), Lactobacillus brevis (P102), Lactobacillus casei (P9, DSMZ 20011), Lactobacillus plantarum (P1), Lactobacillus pentosus (P4), Lactobacillus rhamnosus (P5, TISTR 541), Bifidobacterium longum (BL) and Bifidobacterium lactis (P7, Bb-12) for the production of CLA in the MRS broth was investigated. Two vegetable oils (sun flower oil & linseed oil) and cod liver oil were used as substrates in MRS media. The oils were added to MRS in concentration of 10 mg/ml and incubated for three days at 37°C. The ability of lactic acid bacteria under the investigation as inhibitors were evaluated by the determination of the amount of conjugated linoleic acid at the end of the fermentation period. The results indicated that there were significant differences between the microorganisms in their ability to produce CLA. Furthermore, there were significant differences between oil types as substrate on the impact of CLA production. Bifidobacterium lactis showed the highest production of CLA (618.13 µg/ml) in MRS media fortified with cod liver oil. From the results, it can be concluded that there were positive impacts for both oils and lactic acid bacteria on the production of CLA. Therefore, the lactic acid bacteria grown in these oils can be utilized for probiotic production purposes and to produce other bioactive compounds.
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Gawade, Pranotee. "Lactic Acid Bacteria as A Bio Preservative: Importance and Production". International Journal for Research in Applied Science and Engineering Technology 9, nr 10 (31.10.2021): 233–34. http://dx.doi.org/10.22214/ijraset.2021.38406.

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Abstract: Biopreservation is the method of employing natural microflora and their antimicrobial compounds to extend the storage life and improve the safety of foods. Streptococcus lactis was the first pure strain of lactic acid bacteria which was isolated from milk by Liszt. He named it bacterium lactis. Lactic acid bacteria are gram-positive, acid-tolerant, have low Guanine-Cytosine content and are generally non-sporulating, non-respiring, either spherical cocci or rod-shaped bacilli bacteria that share most of them their metabolic and physiological characteristics. These bacteria are mostly present in decomposing plants and milk products. They have an increased tolerance to acidity. Most species are incapable of respiration and therefore media used for lactic acid bacteria include a carbohydrate source. At the end of carbohydrate fermentation, these bacteria give out lactic acid as a major end product. The review focuses on the process of lactic acid production by lactic acid bacteria and its expanding importance in a variety of disciplines. Keywords: Lactic acid bacteria, bio preservative, food, microflora
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Hwang, Hyelyeon, i Jong-Hee Lee. "Characterization of Arginine Catabolism by Lactic Acid Bacteria Isolated from Kimchi". Molecules 23, nr 11 (21.11.2018): 3049. http://dx.doi.org/10.3390/molecules23113049.

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Kimchi fermentation depends on diverse lactic acid bacteria, which convert raw materials into numerous metabolites that contribute to the taste of food. Amino acids and saccharides are important primary metabolites. Arginine is nearly exhausted during kimchi fermentation, whereas the concentrations of other amino acids are reported not to increase or decrease dramatically. These phenomena could imply that arginine is an important nutritional component among the amino acids during kimchi fermentation. In this study, we investigated the arginine-catabolism pathway of seven lactic acid bacteria isolated from kimchi and evaluated the products of arginine catabolism (citrulline and ornithine) associated with the bacteria. The arginine content dramatically decreased in cultures of Lactobacillus brevis and Weissella confusa from 300 μg/mL of arginine to 0.14 ± 0.19 and 1.3 ± 0.01 μg/mL, respectively, after 6 h of cultivation. Citrulline and ornithine production by L. brevis and W. confusa showed a pattern that was consistent with arginine catabolism. Interestingly, Pediococcus pentosaceus, Lactobacillus plantarum, Leuconostoc mesenteroides, and Leuconostoc lactis did not show increased citrulline levels after arginine was added. The ornithine contents were higher in all bacteria except for L. lactis after adding arginine to the culture. These results were consistent with the absence of the arginine deiminase gene among the lactic acid bacteria. Arginine consumption and ornithine production were monitored and compared with lactic acid bacteria by metagenomics analysis, which showed that the increment of ornithine production correlated positively with lactic acid bacteria growth.
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Sârbu, Ionela, Tatiana Vassu, Ileana Stoica, Carmen Chifiriuc, Marcela Bucur, Elena Rusu, Robertina Ionescu i Diana Pelinescu. "Analysis on the antimicrobial activity of some lactic acid bacteria strains". Romanian Journal of Infectious Diseases 18, nr 2-3 (30.09.2015): 87–91. http://dx.doi.org/10.37897/rjid.2015.2-3.6.

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Objective. The main objective of this study was to select lactic acid bacteria strains with antimicrobial activity and to identify and characterize the antimicrobial compounds. Methods. In this study we tested the antimicrobial activity of 153 lactic bacteria strains by disk diffusion method against 6 microbial pathogenic strains isolated from patients with urinary and vaginal infections. Results. Antimicrobial test results revealed that most of lactic acid bacteria strains exhibited high antimicrobial activity against pathogenic microorganisms. For most of lactic bacteria strains antimicrobial activity has been correlated with the production of organic acids and only for two strains with the biosynthesis of bacteriocins. Bacteriocin produced by Lactococcus (Lc.) lactis F2a strain presented a broad spectrum of activity and high activity (51,200 AU/ml) compared with bacteriocins isolated from Lactobacillus (Lb.) paracasei ssp. paracasei JR strain (400 AU/ml). The stability tests of bacteriocin revealed that the bacteriocin produced by Lc. lactis F2a strain, it is stable at acid pH while exposure for long time to 600C causes a drastic decrease in bacteriocin activity. Conclusions. Lactic bacteria strains showed a high antimicrobial activity against both prokaryotic and eukaryotic pathogen strains. Two bacterial strains have bacteriocins. Bacteriocins isolated from Lc. lactis F2a strain showed a high activity and a broad spectrum of action.
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Karovičová, J., i Z. Kohajdová. "Lactic acid fermented vegetable juices". Horticultural Science 30, No. 4 (28.11.2011): 152–58. http://dx.doi.org/10.17221/3878-hortsci.

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Vegetable juices processed by lactic acid fermentation bring about a change in the beverage assortment for their high nutritive value, high content of vitamins and minerals. Starter cultures of the genus Lactobacillus are added into juices to achieve their desirable properties. This review describes the manufacture of lactic acid fermented vegetable juices and beneficial effects of the lactic acid bacteria (mainly antimicrobial and anticancer effects). A separate part of research is devoted to nutrition aspects of lactic acid fermentation and to the occurrence of biogenic amines in lactic acid fermented vegetables and vegetable juices.  
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GOURAMA, HASSAN, i LLOYD B. BULLERMAN. "Antimycotic and Antiaflatoxigenic Effect of Lactic Acid Bacteria: A Review†". Journal of Food Protection 58, nr 11 (1.11.1995): 1275–80. http://dx.doi.org/10.4315/0362-028x-58.11.1275.

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Lactic acid bacteria are extensively used in the fermentation of a wide variety of food products and are known for their preservative and therapeutic effects. Many lactic acid bacteria species have been reported to inactivate bacterial pathogens, and numerous antibacterial substances have been isolated. However, the antimycotic and antimycotoxigenic potential of lactic acid bacteria has still not been fully investigated. Fermented foods such as cheese can be contaminated by molds and mycotoxins. Mold causes spoilage and renders the product unusable for consumption, and the presence of mycotoxins presents a potential health hazard. A limited number of reports have shown that lactic acid bacteria affect mold growth and aflatoxin production. Although numerous lactic acid bacteria such as Lactobacillus spp. were found to inhibit aflatoxin biosynthesis, other lactic bacteria such as Lactococcus lactis were found to stimulate aflatoxin production. The morphology of lactic acid bacteria cells has also been found to be affected by the presence of fungal mycelia and aflatoxin. Lactococcus lactis cells became larger and formed long chains in the presence of Aspergillus flavus and aflatoxins. Numerous investigations reported that low pH, depletion of nutrients, and microbial competition do not explain the reason for aflatoxin inhibition. Some investigators suggested that the inhibition of aflatoxin is due to lactic acid and/or lactic acid bacteria metabolites. These metabolites have been reported to be heat-stable low-molecular-weight compounds.
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Vaitheeswaran, Nataraja Iyer, i Gajanan S. Bhat. "Influence of lactic cultures in denaturation of whey proteins during fermentation of milk". Journal of Dairy Research 55, nr 3 (sierpień 1988): 443–48. http://dx.doi.org/10.1017/s0022029900028697.

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SummaryUndenatured whey protein (UWP) content of skim milk acidified with lactic acid or cultured with lactic cultures was estimated by a dye-binding method. The UWP content decreased with increase in acidity and the denaturation was only partly reversible on neutralization to the original acidity. The decrease in UWP was higher in cultured milk than in the milk acidified to the same extent with lactic acid, indicating the effect of lactic cultures in denaturation of whey proteins during fermentation of milk. Among the lactic cultures the denaturation effect of Lactobacillus delbrueckii subsp. bulgaricus was highest, followed by Streptococcus salivarius subsp. thermophilus, Lactococcus lactis subsp. lactis and Lact. lactis biovar diacetylactis. Denaturation of whey proteins by lactic cultures was found to be partly irreversible.
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Rozprawy doktorskie na temat "Lactic acid"

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Pradhan, Nirakar. "Hydrogen and lactic acid synthesis through capnophilic lactic fermentation by Thermotoga neapolitana". Thesis, Paris Est, 2016. http://www.theses.fr/2016PESC1145/document.

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Les énergies non-renouvelables ont été d’un apport capital dans l’industrialisation et l’urbanisation dans les derniers centenaires. L’exploitation excessive des réserves d’hydrocarbures et son impact environnemental ont contribué au developpement de plusieurs technologies durables à caractère néo-carbone neutre. A cet effet, les processus biologiques comme la fermentation pourraient être exploités pour convertir biologiquement le hydrates de carbone en énergies comme l’hydrogène (H2) ou des acides organiques commercialement rentables. Ce travail a étudié les techniques d’ingénierie pour améliorer la synthèse simultanée d’H2 et d’acide lactique à travers des conditions de fermentation capnophile lactique (CLF) par une souche de labo de Thermotoga neapolitana.En un premier temps, une comparaison génotypique entre la souche de labo et celle sauvage a révélé une ressemblance de 88,1 (±2,4) %. En plus, les analyses du génotypage par RiboPrint® et par spectroscopie de masse matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF MS) ont montré une différentiation génétique au-delà du niveau sous-espèce ; et par conséquent la souche de labo a été proposée comme sous-espèce, T. neapolitana subsp. lactica. Basé sur la caractérisation phénotypique, la souche de labo produisait 10-90% plus d’acide lactique que celle sauvage sous les mêmes conditions sans pour autant affecté le taux de production d’H2.La souche de labo a donc été étudiée pour aussi bien optimiser les conditions de croissance que pour estimer les paramètres cinétiques de croissance. Un nouveau modèle cinétique basé sur les principes de fermentation à l’obscurité (DF) et les expressions mathématiques Monod ont été développés pour permettre la simulation de la croissance en biomasse, la consommation de substrat, et la formation de produit. Le modèle n’a cependant pas pu faire une estimation des acides acétique et lactique avec précision du fait que le modèle DF n’a pas considéré la carboxylation de l’acide acétique en acide lactique par l’enzyme pyruvate ferrédoxine oxydoréductase (PFOR) sous les conditions CLF.Le model a été associé avec le mécanisme CLF et les paramètres cinétiques ont été recalibrés. Les paramètres cinétiques que sont le taux d’absorption spécifique maximum (k), la constante semi-saturation (ks), le coefficient en rendement biomasse (Y), et le taux de décomposition interne (kd) étaient de 1,30 l/h, 1,42 g/L, 0,12 et 0,02 l/h. Fait intéressant, le nouveau modèle CLF s’est parfaitement adapté avec les résultats expérimentaux et a estimé que près de 40-80% de la production d’acide lactique est attribué au recyclage de l’acide acétique et le CO2.En plus, l’adsorption de l’acide lactique par le carbone actif et les résines polymères anioniques a été appliquée avec succès comme technique de transformation en aval dans la récupération et la purification de l’acide lactique à partir du modèle de fermentation type T. neapolitana. Pour ce faire, ce travail de recherche constitue une étape majeure dans le domaine de la fermentation bactérienne utilisable pour de vastes applications scientifiques prenant en compte le développement d’énergies renouvelables et la production industrielle d’acide lactique
The environmental impact of excessive exploitation of fossil fuel reserves has inspired the innovation of several sustainable neo-carbon-neutral technologies. To that end, the biological processes like fermentation may be leveraged to bioconvert carbohydrate-rich feedstocks to fuels like hydrogen (H2) or commercially valuable organic acids like lactic acid. This research work investigated the engineering techniques for improving simultaneous synthesis of H2 and lactic acid under capnophilic (CO2-dependent) lactic fermentation (CLF) conditions by a lab strain of Thermotoga neapolitana.Primarily, the genotypic comparison between the lab strain and the wild-type revealed DNA homology of 88.1 (± 2.4)%. Genotyping by RiboPrint® and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analyses showed a genetic differentiation beyond subspecies level, hence the lab strain was proposed as a new subspecies, T. neapolitana subsp. lactica. The lab strain produced 10-90% more lactic acid, based on the phenotypic characterization, than the wild-type strain under similar operating conditions without impairing the H2 yield.The lab strain was then studied to optimize the growth conditions as well as to estimate the growth kinetic parameters. A new mathematical model based on the dark fermentation (DF) principles and Monod-like kinetic expressions was developed to enable the simulation of biomass growth, substrate consumption and product formation. The model failed to estimate acetic and lactic acid accurately, as the DF model did not consider the carboxylation of acetic acid to lactic acid by the pyruvate:ferredoxin oxidoreductase (PFOR) enzyme under CLF conditions. The model was then incorporated with the CLF mechanism and the kinetic parameters were recalibrated.The calibrated kinetic parameters, i.e. maximum specific uptake rate (k), semi-saturation constant (kS), biomass yield coefficient (Y) and endogenous decay rate (kd) were 1.30 1/h, 1.42 g/L, 0.12 and 0.02 1/h, respectively, under CLF conditions. The new CLF-based model fitted very well with the experimental results and estimated that about 40-80% of the lactic acid production is attributed to the recycling of acetic acid and CO2.In addition, the adsorption of lactic acid by activated carbon and anionic polymeric resins was successfully applied as a downstream processing technique for the recovery of lactic acid from a model T. neapolitana fermentation broth. This research work serves as a practical milestone in the field of microbial fermentation with a scope for wider scientific applications, including the development of bio-based renewable energy and industrial lactic acid production
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Khivasara, M. B. "Biomass to lactic acid: microbial cellulases and their application in cellulosic lactic acid production". Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 2015. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/1993.

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Wang, Peiyao. "Stereopure Functionalized Poly(lactic acid)". University of Akron / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=akron1366631276.

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Kanagachandran, Kanagasooriyam. "The physiology of lactic acid production by Lactococcus lactis IO-1". Thesis, University of Hertfordshire, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267963.

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Kishino, Shigenobu. "Production of conjugated fatty acids by lactic acid bacteria". Kyoto University, 2005. http://hdl.handle.net/2433/86244.

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Kyoto University (京都大学)
0048
新制・課程博士
博士(農学)
甲第11617号
農博第1473号
新制||農||905(附属図書館)
学位論文||H17||N4010(農学部図書室)
UT51-2005-D366
京都大学大学院農学研究科応用生命科学専攻
(主査)教授 清水 昌, 教授 加藤 暢夫, 教授 植田 充美
学位規則第4条第1項該当
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Magnusson, Jesper. "Antifungal activity of lactic acid bacteria /". Uppsala : Dept. of Microbiology, Swedish Univ. of Agricultural Sciences, 2003. http://epsilon.slu.se/a397.pdf.

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Oliveira, Juliana de. "Poly(Lactic acid) production by conventional and microwave polymerization of lactic acid produced in submerged fermentation". reponame:Repositório Institucional da UFPR, 2016. http://hdl.handle.net/1884/46421.

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Orientador : PhD. Luciana Porto de Souza Vandenberghe
Coorientadores : PhD. Carlos Ricardo Soccol e PhD. Sônia Faria Zawadzki
Tese (doutorado) - Universidade Federal do Paraná, Setor de Tecnologia, Programa de Pós-Graduação em Engenharia de Bioprocessos e Biotecnologia. Defesa: Curitiba, 09/06/2016
Inclui referências : f. 115-128
Área de concentração: Agroindústria e biocombustíveis
Resumo: Poli(ácido lático), poliéster, é um polímero biodegravável aplicado em produtos como embalagens, têxteis, médicos e farmacêuticos. Pode ser obtido a partir do monômero ácido lático (AL) por meio da reação de policondensação direta e pela polimerização por abertura de anel do lactídeo. O AL é um ácido orgânico que apresenta diversas aplicações principalmente na indústria alimentícia, assim como na indústria farmacêutica, química e de polímeros. A produção do AL por fermentação oferece vantagens tais como a produção do isômero opticamente puro. As necessidades nutricionais da bactéria aumentam o custo de produção do AL, portanto substratos alternativos tem sido estudados por apresentarem uma alternativa econômica para este processo. O objetivo deste trabalho foi a produção de ácido lático por Lactobacillus pentosus em fermentação submersa utilizando subproduto do processamento da batata e caldo de cana como substratos para a obtenção de poli(ácido lático). Estes sub-produtos porque possuem alta concentração de fonte de carbono e volumes significativos são gerados anualmente, o que justifica sua a re-utilização e valorização. O sub-produto do processamento da batata foi submetido a hidrólise ácida com o objetivo de converter o amido em glucose. A produção de AL foi otimizada utilizando etapas de planejamento experimental estatístico envolvendo a seleção de bactérias do gênero Lactobacillus, definição da composição do meio de cultivo e estudos de cinética em frascos de Erlenmeyer e biorreator do tipo tanque agitado. A produção de AL chegou a 150 g/L utilizando sub-produto do processamento da batata e 225 g/L utilizando caldo de cana em 96 horas de fermentação. O uso da célula inteira de levedura de panificação como fonte de nitrogênio e a condição de fermentação não estéril demostraram ser boas alternativas para um processo industrial de produção de AL. O processo de separação e recuperação do AL do caldo fermentado foi desenvolvido para obtenção da molécula purificada e estudos de polimerização com o monômero obtido. O processo desenvolvido consistiu no aquecimento do caldo fermentado seguido pela etapa de centrifugação. A etapa de clarificação foi realizada utilizando carvão ativado em pó seguida pela precipitação a baixa temperatura e acidificação do lactato de cálcio para conversão em ácido lático. O processo foi efetivo para remoção de contaminantes que estavam presentes no caldo fermentado. A concentração final de AL em solução aquosa foi de 416 g/L com um rendimento de 51%. Os estudos de polimerização foram desenvolvidos utilizando a técnica de policondensação direta do AL, por meio de dois diferentes sistemas de aquecimento, convencional e micro-ondas. Um polímero com massa molar de 6330 g/mol e 61% de rendimento foi obtido a partir de um AL comercial e utilizando o AL obtido por fermentação resultou em um polímero com massa molar de 2370 g/mol. O processo de aquecimento por micro-ondas proporcionou um maior rendimento, 79% e 76% para o AL comercial e obtido por fermentação, respectivamente. Porém, foi obtida menor massa molar que o processo convencional, 2070 para o AL comercial e 1450 para o AL obtido por fermentação. As propriedades físico-químicas do poli(ácido lático) demonstraram aplicação em encapsulamento de compostos bioativos e engenharia de tecido. As perspectivas de sequência de estudos são a aplicação em encapsulamento de moléculas, modificações do polímeros e desenvolvimento de compósitos. PALAVRAS CHAVE: Poli(ácido lático), sub-produto do processamento da batata, caldo de cana, policondensação
Abstract: Poly (lactic acid) (PLA) is a polyester, which has a predominant role as biodegradable plastic, that is applied in packaging, textile, medical and pharmaceutical products. It can be obtained from lactic acid by direct polycondensation and by ring-opening polymerization (ROP) of lactide. Lactic acid (LA) is an organic acid that presents diverse applications mostly in food industry, as well as in pharmaceutical, chemical industries and polymers. The production of LA by fermentation offers the advantage of producing optically high pure LA. Nutritional requirements of bacteria increase the cost of LA production so alternatives substrates have been studied to bring an economical alternative for this process. The aim of this work was the production of LA by Lactobacillus pentosus in submerged fermentation using potato processing waste and sugarcane juice as substrate in order to obtain poly(lactic acid). The fermentation process was developed using potato processing waste and sugarcane juice because of their high carbon source concentration. Important volumes of both sub-products were generated, which is another reason for their re-use and valorization. Potato processing waste was submitted to hydrolysis in order to convert starch to glucose. LA production by fermentation was optimized using, statistical experimental design approach steps of optimization involved the screening of bacteria of the genus Lactobacillus and definition of medium composition kinetics studies in Erlenmeyer flask and stirred tank reactor were also carried out. LA production reached 150 g/l using potato processing waste, it was and 225 g/l with sugar cane juice after 96 hours of fermentation. The use of baker's yeast as a source of nitrogen and nonsterile conditions demonstrated good alternatives for an industrial production process of LA. The separation and recovery process of LA from fermented broth was developed to obtain a purified molecule for further polymerization studies. The developed process consisted in heating the fermented broth, then a centrifugation step was conducted for removal of the cells and suspended solids. A clarification step was included with powered activated carbon with further precipitation at low temperature and acidification of calcium lactate to convert to LA. The process was effective for removal of contaminants that were present in the fermentation medium. Final concentration of LA in aqueous solution reached 416 g/l and a yield of 51%. Polymerization studies were then carried out using direct polycondensation of LA, that were carried out with two different heating systems, conventional and microwave heating. A polymer with 6330 g/mol of molecular weight and 61% of yield was obtained from commercial LA and using fermented LA resulted in 2370 g/mol. Microwave heating process provided a higher yield, 79% and 76% for commercial and fermented LA, respectively. Nevertheless, the molecular weight was lower than conventional process, 2070 for commercial LA and 1450 for fermented LA. Physicochemical properties of PLA demonstrated application in encapsulation of bioactive compounds and tissue engineering. Perspectives of sequence of the studies: application on encapsulation of molecules, modifications of polymer and development of composites. KEYWORDS: Poly(lactic acid); potato processing waste; sugarcane juice; polycondensation
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Humphreys, S. "Glycopeptide resistance in lactic acid bacteria". Thesis, University of Cambridge, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.604779.

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The glycopeptide antibiotics vancomycin and teicoplanin are used to treat infections caused by Gram positive bacteria. The formation of nascent peptidoglycan chains and cross linking of the cell wall is inhibited because the drugs bind specifically to the D-alanyl-D-alanine portion of the pentapeptide chain in peptidoglycan precursors. Plasmid-mediated, high-level resistance to both antibiotics in Enterococcus sp. is associated with production of a novel D-alanine:D-alanine (D-Ala:D-Ala) ligase of altered substrate specificity. This enzyme, VanA, synthesises the depsipeptide D-alanyl-D-lactate (D-Ala-D-Lac), which is incorporated into cell wall precursors, instead of D-Ala-D-Ala. Vancomycin has a 1000 fold lower affinity for cell wall precursors terminating in the hydroxyacid. VanA and other plasmid-borne van genes essential for high-level glycopeptide resistance in enterococci lie within the inverted repeats of a transposon; Tn1546, which has a distinctly different G+C ratio to enterococcal DNA, suggesting an exogenous origin. Lactic acid bacteria such as Lactobacillus sp. and Leuconostoc sp. are intrinsically resistant to glycopeptide antibiotics. Analysis of their cell wall precursors reveals that they terminate in D-Lac, suggesting a similar mechanism of resistance to that of the enterococci. The mechanism of cell wall synthesis in vancomycin-sensitive and resistant lactic acid bacteria and VanA-type enterococci was investigated. The D-Ala:D-Ala ligase from the glycopeptide-sensitive lactic acid bacterium, Lactobacillus delbrueckii, was purified directly from cell extracts and characterised. No D-Ala:D-hydroxyacid ligase activity was detected in extracts from the glycopeptide-resistant Lactobacillus brevis. Subsequently, the ligase of Leuconostoc mesenteroides (Lmddl), which had already been sequenced, was cloned and overexpressed, to allow purification and characterisation of the enzyme.
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Nuraida, Lilis. "Metabolic studies on lactic acid bacteria". Thesis, University of Reading, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314794.

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Gostick, Dominic Owen. "Transcription regulators of lactic acid bacteria". Thesis, University of Sheffield, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.286585.

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Książki na temat "Lactic acid"

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Chen, Wei, red. Lactic Acid Bacteria. Singapore: Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-13-7283-4.

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Chen, Wei, red. Lactic Acid Bacteria. Singapore: Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-13-7832-4.

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Auras, Rafael, Loong-Tak Lim, Susan E. M. Selke i Hideto Tsuji, red. Poly(Lactic Acid). Hoboken, NJ, USA: John Wiley & Sons, Inc., 2010. http://dx.doi.org/10.1002/9780470649848.

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Holzapfel, Wilhelm H., i Brian J. B. Wood, red. Lactic Acid Bacteria. Chichester, UK: John Wiley & Sons, Ltd, 2014. http://dx.doi.org/10.1002/9781118655252.

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Kanauchi, Makoto, red. Lactic Acid Bacteria. New York, NY: Springer New York, 2019. http://dx.doi.org/10.1007/978-1-4939-8907-2.

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Faruk Bozoğlu, T., i Bibek Ray, red. Lactic Acid Bacteria. Berlin, Heidelberg: Springer Berlin Heidelberg, 1996. http://dx.doi.org/10.1007/978-3-642-61462-0.

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Zhang, Heping, i Yimin Cai, red. Lactic Acid Bacteria. Dordrecht: Springer Netherlands, 2014. http://dx.doi.org/10.1007/978-94-017-8841-0.

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Socie te de chimie biologique., red. Lactic acid bacteria. Paris: Elsevier, under the auspices of Socie te de Chimie Bologique, 1988.

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Vinderola, Gabriel, Arthur Ouwehand, Seppo Salminen i Atte von Wright. Lactic Acid Bacteria. Wyd. 6. Boca Raton: CRC Press, 2024. http://dx.doi.org/10.1201/9781003352075.

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Steinka, Izabela. Lactic acid cheese safety. New York: Nova Science Publishers, 2008.

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Części książek na temat "Lactic acid"

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Bährle-Rapp, Marina. "Lactic Acid". W Springer Lexikon Kosmetik und Körperpflege, 308. Berlin, Heidelberg: Springer Berlin Heidelberg, 2007. http://dx.doi.org/10.1007/978-3-540-71095-0_5751.

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Ren, Jie. "Lactic Acid". W Biodegradable Poly(Lactic Acid): Synthesis, Modification, Processing and Applications, 4–14. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-17596-1_2.

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Cleaves, Henderson James. "Lactic Acid". W Encyclopedia of Astrobiology, 1. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-642-27833-4_856-4.

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Cleaves, Henderson James. "Lactic Acid". W Encyclopedia of Astrobiology, 1355–56. Berlin, Heidelberg: Springer Berlin Heidelberg, 2015. http://dx.doi.org/10.1007/978-3-662-44185-5_856.

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Cleaves, Henderson James. "Lactic Acid". W Encyclopedia of Astrobiology, 903. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-11274-4_856.

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Gooch, Jan W. "Lactic Acid". W Encyclopedic Dictionary of Polymers, 417. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-6247-8_6735.

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Cleaves, Henderson James. "Lactic Acid". W Encyclopedia of Astrobiology, 1. Berlin, Heidelberg: Springer Berlin Heidelberg, 2022. http://dx.doi.org/10.1007/978-3-642-27833-4_856-5.

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Okano, Kenji, Tsutomu Tanaka i Akihiko Kondo. "Lactic Acid". W Bioprocessing of Renewable Resources to Commodity Bioproducts, 353–80. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2014. http://dx.doi.org/10.1002/9781118845394.ch13.

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Cleaves, Henderson James. "Lactic Acid". W Encyclopedia of Astrobiology, 1642–43. Berlin, Heidelberg: Springer Berlin Heidelberg, 2023. http://dx.doi.org/10.1007/978-3-662-65093-6_856.

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Reddi, Alluru S. "Lactic Acidosis". W Acid-Base Disorders, 63–83. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-28895-2_5.

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Streszczenia konferencji na temat "Lactic acid"

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Alhamad, Luai, Basil Alfakher, Abdullah Alrustum i Sajjad Aldarweesh. "Experimental Results to Design Lactic Acid for Carbonate Acidizing". W Abu Dhabi International Petroleum Exhibition & Conference. SPE, 2021. http://dx.doi.org/10.2118/207273-ms.

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Abstract Acidizing deep carbonate formations by Hydrochloric acid (HCl) is a complex task due to high reaction and corrosion rates. Mixing organic acids with HCl is a typical method to reduce the acid's reactivity and corrosivity. Lactic acid has not been investigated completely in the area of carbonate acidizing. Lactic acid has a dissociation constant similar to formic acid, which is approximately 10 times larger than acetic acid. Therefore, the objective of this work is to compare lactic/HCl blends with plain HCl and formic/HCl blends. Corrosion tests were conducted at high temperature on C-95 steel coupons to investigate associated corrosion damage. Coreflood tests were performed on Indiana limestone cores to mimic matrix acidizing treatment and to investigate amount of pore volumes required to breakthrough. All blends were prepared to be equivalent to 15 wt% (4.4 M) HCl for comparison. Lactic and formic acid concentrations were set to be (0.5 or 1 M), and HCl concentration was calculated as appropriate to reach a blend with strength of 4.4 M. In terms of corrosivity evaluation, blends of lactic and HCl acids showed a corrosion rate of up to 1.97 lb/ft2 at 300°F. The formic and HCl blend showed a corrosion rate of 1.68 lb/ft2 at the same temperature. The difference in corrosion rates between the two mixtures is due to molecular weight difference between lactic and formic acids. When both acids were prepared at 1 M, lactic acid blend required more HCl to be equivalent to 15 wt% HCl acid which was associated with an increase in corrosion rate. Coreflood results established acid efficiency curves for lactic/HCl acid blends. The curves highlighted the correlation between acid-core reactivity, injection rate, and dissolution pattern. Lactic/HCl blend was less reactive than formic/HCl mixture as the last required lower injection rate to obtain optimum pore volume to breakthrough at 300°F. Lactic/HCl blend was able to generate an optimum dissolution pattern as a dominant wormhole was shown on tested core plugs inlet face. This study expands the investigation of lactic acid utilization in carbonate acidizing. Major advantages rendered by using lactic acid with HCl include: (1) favorable dissolution pattern due to lactic acid being less reactive than HCl or formic acids, and (2) less corrosion rates comparing to HCl, that can reduce allocated costs for maintenance and replacements.
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Uryadova, G. T., N. A. Fokina i L. V. Karpunina. "Film coatings based on exopolysaccharides of lactic acid bacteria and their use". W 2nd International Scientific Conference "Plants and Microbes: the Future of Biotechnology". PLAMIC2020 Organizing committee, 2020. http://dx.doi.org/10.28983/plamic2020.263.

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Bettencourt, Greyson Soares, Ding Zhu, A. D. Hill i Chad Kamman. "Experimental Evaluation of Lactic Acid for Matrix Acidizing of Carbonates". W SPE Annual Technical Conference and Exhibition. SPE, 2023. http://dx.doi.org/10.2118/214956-ms.

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Abstract To improve efficiency of standard HCl stimulation treatments, many alternative acid systems have been developed to mitigate corrosion, increase wormhole efficiency, and divert fluids for better acid coverage. However, these alternative systems come at a price compared to HCl which is cheaper and sufficient in most applications. Lactic acid is an organic acid that is less corrosive and has reduced reactivity compared to HCl. The advantage and application of lactic acid has not been studied extensively like other alternative acids. To evaluate lactic acid as a viable alternative acid system, we conducted a series of linear core flood matrix acidizing experiments using 40 weight percent lactic acid at two temperatures over a range of injection rates. The goal was to characterize the wormholes created by lactic acid and identify the appropriate condition that lactic acid can outperform HCl. Core flood tests were also conducted at high temperature and lower concentrations to observe change in behavior and performance. Lactic acid performance was analyzed by comparing pore volumes to breakthrough (PVbt) with previous HCl experiments. Lactic acid was found to be more efficient than HCl at injection rates below optimum for 40 %. At the lower temperature of 150 °F, lactic acid maintained similar PVbt over the range of injection rates. Wormhole geometry from CT imagery and pressure response data was studied to identify unique characteristics or behavior lactic acid may have. CT images of lactic acid generated wormholes reveal a geometry versus injection rate relationship that is contrary to the conventional understanding of wormhole growth patterns. Images show extensive branching in most low injection rate tests. The results are characterized as appearing to have self-diverting behavior. Pressure differential data across the core shows pressure drop increases in nearly every experiment. For the lower concentration tests, pressure differential increase was not observed for 10 % and 20 % and only occurred at 30 % lactic acid. Precipitation occurred during and immediately after most high temperature experiments and after the 30 % test which is suspected to be plugging permeable channels. Further investigation may provide more insight into the unique capabilities of a simple yet overlooked acid system.
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Alhamad, Luai, Sinan Caliskan, Basil Alfakher i Hussain Ibrahim. "New Insights for the Use of Lactic Acid in Carbonate Acidizing". W Middle East Oil, Gas and Geosciences Show. SPE, 2023. http://dx.doi.org/10.2118/213597-ms.

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Abstract Utilizing HCl on deep high-temperature formations is associated with corrosion and reactivity concerns. Organic acids are a common choice for conducting matrix acidizing on carbonate formations where the use of HCl is limited or unfavorable. An organic acid can stimulate as a standalone formulation, mixed with another type of organic acid, or mixed with HCl. One commonly used organic acid is Lactic acid, which has a dissociation constant similar to formic acid, which is approximately 10 times larger than acetic acid. The objective of this work is to show experimental results conducted using lactic acid for matrix acidizing. Solubility tests using a HPHT autoclave were done to evaluate acid-carbonate reaction and produced by-product salts. Coreflood tests were performed on Indiana limestone core plugs to mimic a matrix acidizing procedure and to investigate the amount of pore volumes required to breakthrough. These tests were monitored by using inductively coupled plasma (ICP), X-ray diffraction (XRD), and computed tomography (CT) scans to measure different ion concentrations in solution, to identify precipitated solids, and to evaluate dissolution patterns generated in the coreflood test, respectively. The reaction of lactic acid with carbonate rocks was associated with production of calcium lactate which found to be soluble above 150°F. Lactate-based precipitation was avoided by incorporating gluconic acid along with lactic acid. In addition, lactate-based precipitation was avoided by mixing low concentration lactic acid with HCl. Adding HCl to lactic acid solution allowed for the reduction of lactic acid concentration to a precipitation-free level where lactate ions would be at a minimum. Coreflood results established more understanding of lactic acid utilization in matrix acidizing in terms of minimum pore volumes to breakthrough and generated wormholes. The results highlighted the correlation between acid-core reactivity, injection rate, and dissolution pattern. Coreflood tests showed that the lactic acid blends at optimum injection rate penetrated tested core plugs with minimal acid pore volume without any face dissolution or salt precipitation on the plug faces. Coreflood tests showed that the lactic/gluconic acid blend can stimulate carbonate cores and generate an optimum wormhole. A lactic/HCl blend was more reactive than a formic/HCl or lactic/gluconic acid blends as more pore volumes were needed to breakthrough Indiana core plugs. Thereby, a higher injection rate is required to obtain an optimum pore volume to breakthrough despite the high reactivity. The detailed experimental work shown in this study shows major advantages that can be achieved by using different lactic acid-based blends. Among these advantages are favorable dissolution pattern due to lactic acid retardation, and less corrosion rates that can reduce allocated costs for maintenance and replacements.
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Srithep, Yottha, Dutchanee Pholharn i John Morris. "Injection-molded poly(L-lactic acid)/poly(D-lactic acid) blends: Thermal and mechanical properties". W MATERIALS CHARACTERIZATION USING X-RAYS AND RELATED TECHNIQUES. Author(s), 2019. http://dx.doi.org/10.1063/1.5088277.

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Faisal, M., T. Saeki, H. Tsuji, H. Daimon i K. Fujie. "Recycling of poly lactic acid into lactic acid with high temperature and high pressure water". W WASTE MANAGEMENT 2006. Southampton, UK: WIT Press, 2006. http://dx.doi.org/10.2495/wm060251.

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STOŠKUS, Robertas, Jonas JATKAUSKAS, Vilma VROTNIAKIENĖ i Vida JUOZAITIENĖ. "THE EFFECT OF HOMO - AND HETERO - FERMENTATIVE LACTIC ACID BACTERIA MIX ON THE ENSILED LUCERNE FERMENTATION CHARACTERISTICS AND AEROBIC STABILITY IN BIG BALES". W RURAL DEVELOPMENT. Aleksandras Stulginskis University, 2018. http://dx.doi.org/10.15544/rd.2017.029.

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The purpose of this study was to determine the effect of homo- and hetero-fermentative lactic acid bacteria mix on the ensiled lucerne fermentation characteristics and aerobic stability in big bales. The lucerne was ensiled without additives (C) and treated with a mix of bacterial inoculant that contains Lactococcus lactis and Lactobacillus buchneri (50:50) (I). Silage was treated with bacterial inoculant, which significantly increased the total organic acids concentration by 69 %, lactic acid by 92% and acetic acid by 76 %. If the results were compared with the C silage, the inoculation significantly decreased the concentrations of butyric acid by 73 %, ethanol by 53 % and ammonia - N concentration by 33%. Inoculated silage had significantly lowered the yeast count by 59 % and moulds count by 34 %. Compared to the inoculated silage and during the aerobic exposure, the untreated silage maximum temperature was significantly higher (13.9 0C vs 4.6 0C) (P < 0.05). Therefore, the bacterial inoculant improved the quality of fermentation and aerobic stability in lucerne silages.
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Greco, Antonio, i Alfonso Maffezzoli. "Rotational moulding of poly-lactic acid". W PROCEEDINGS OF THE REGIONAL CONFERENCE GRAZ 2015 – POLYMER PROCESSING SOCIETY PPS: Conference Papers. Author(s), 2016. http://dx.doi.org/10.1063/1.4965528.

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Alqahtani, M. F., F. M. Alissa, J. K. El-Demellawi i S. A. Bamigdad. "Calcium Sulfate Dissolution Using Lactic Acid". W SPE Caspian Technical Conference and Exhibition. SPE, 2023. http://dx.doi.org/10.2118/217562-ms.

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Abstract There has been a global surge in scale challenges across the oilfield industry, surpassing other flow assurance challenges. In principle, scale refers to the deposition of mineral solids (primarily inorganic), such as calcium carbonate, calcium sulfate, or barium sulfate, that can accumulate and obstruct flow pathways in various industries, including oil and gas production, water treatment, and other industrial processes. Scale formation can lead to reduced production rates, increased energy consumption, equipment damage, and operational disturbances. Hence, the mitigation and prevention of scale deposition have become pivotal for maintaining high-performing production processes. In this regard, among the known scales, the calcium sulfate scale, in the form of gypsum (CaSO2.2H2O), is deemed challenging for many applications. This type of scale is usually caused by mixing incompatible waters. CaSO2.2H2O is an acid-insoluble scale; thus, it requires an effective scale dissolving recipe. Herein, we demonstrate the use of lactic acid (C3H6O3) as an emerging green chemical to remove gypsum deposits in the presence of different bases, including potassium and sodium carbonates and hydroxides. Different scale removal recipes were developed comprising mixtures of lactic acid with individual bases or a mixture of two bases. We show that, generally, hydroxide bases have exhibited lower performance, particularly potassium hydroxide, compared to their carbonate counterparts. Nonetheless, potassium carbonate, in particular, has offered a better performance compared to sodium carbonate. Incorporating lactic acid with the experimented bases has further improved the performance of the developed recipes, thanks to the induced synergistic effect, specifically with potassium carbonate. The latter has also demonstrated the ability to polymerize lactic acid when coupled with another base, such as sodium hydroxide or potassium hydroxide. Noteworthy, using sodium carbonate has resulted in much lower performances when coupled with the other hydroxide bases. Therefore, mixing two bases when dissolving calcium sulfate is not always the optimum choice as it brings other negative consequences.
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Ninan, Chinnu Mariam, Ramu Radhakrishnan, K. P. Ramaswamy i R. Sajeeb. "Investigation on Aggressiveness of Organic Acids on Degradation of Ordinary Portland Cement Mortar". W 6th International Conference on Modeling and Simulation in Civil Engineering. AIJR Publisher, 2023. http://dx.doi.org/10.21467/proceedings.156.4.

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Vulnerability of concrete when exposed to low pH acidic environment is a phenomenon known for its significance in the durability of concrete structures. These hostile low pH acidic conditions attack the cement paste and disrupts the equilibrium of the matrix. Mortar specimens prepared with ordinary Portland cement (OPC) responds differently to various organic acid solutions. This study examines the acid aggressiveness on degradation of OPC mortar specimens exposed to 10% concentration lactic acid, acetic acid, citric acid and propionic acid. Acids with higher aggressiveness exhibits higher degradation. This paper compares the effects of different organic acids on cement mortar specimens in terms of mass changes, compressive strength changes and pulse velocity changes. Propionic acid and acetic acid show lower acid aggressiveness comparing to citric acid and lactic acid. Citric acid exhibits a consistency in its degradation and is of higher magnitude. The investigation of aggressiveness of organic acids on OPC mortar aids in predicting degradation to structures on acid exposure and hence preventing the eventual failure of the structure.
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Raporty organizacyjne na temat "Lactic acid"

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Lilga, Michael, Karl Albrecht, Karthikeyan Ramasamy, Teresa Lemmon, Lijian He, Heather Brown, Suh-Jane Lee, J. Frye i Susanne Jones. CONVERSION OF LACTIC ACID TO ACRYLIC ACID AND ITS ESTER DERIVATIVES. Office of Scientific and Technical Information (OSTI), wrzesień 2010. http://dx.doi.org/10.2172/1011533.

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Raman, Sharan. Toughening of Poly L-Lactic Acid using Diblock Copolymers. Ames (Iowa): Iowa State University, styczeń 2018. http://dx.doi.org/10.31274/cc-20240624-1510.

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Stepan, Daniel J., Edwin S. Olson, Richard E. Shockey, Bradley G. Stevens i John R. Gallagher. RECOVERY OF LACTIC ACID FROM AMERICAN CRYSTAL SUGAR COMPANY WASTEWATER. Office of Scientific and Technical Information (OSTI), kwiecień 2001. http://dx.doi.org/10.2172/788118.

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Dai, Y., i C. J. King. Modeling of fermentation with continuous lactic acid removal by extraction utilizing reversible chemical complexation. Office of Scientific and Technical Information (OSTI), lipiec 1995. http://dx.doi.org/10.2172/90681.

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Tsai, S. P., i S. H. Moon. An integrated bioconversion process for the production of L-lactic acid from starchy feedstocks. Office of Scientific and Technical Information (OSTI), lipiec 1997. http://dx.doi.org/10.2172/505310.

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Dr. Sharon Shoemaker. Advanced Biocatalytic Processing of Heterogeneous Lignocellulosic Feedstocks to a Platform Chemical Intermediate (Lactic acid Ester). Office of Scientific and Technical Information (OSTI), wrzesień 2004. http://dx.doi.org/10.2172/829962.

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Kotsilkova, Rumiana, i Vladimir Georgiev. Influence of Graphene Size and Content on Thermal Conductivity of Novel Poly(lactic) Acid Nanocomposites. "Prof. Marin Drinov" Publishing House of Bulgarian Academy of Sciences, kwiecień 2021. http://dx.doi.org/10.7546/crabs.2021.04.06.

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Weinberg, Zwi G., Richard E. Muck, Nathan Gollop, Gilad Ashbell, Paul J. Weimer i Limin Kung, Jr. effect of lactic acid bacteria silage inoculants on the ruminal ecosystem, fiber digestibility and animal performance. United States Department of Agriculture, wrzesień 2003. http://dx.doi.org/10.32747/2003.7587222.bard.

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The overall objective of the whole research was to elucidate the mechanisms by which LAB silage inoculants enhance ruminant performance. The results generated will permit the development of better silage inoculants that maximize both silage preservation and animal performance. For this one-year BARD feasibility study, the objectives were to: 1. determine whether lactic acid bacteria (LAB) used in inoculants for silage can survive in rumen fluid (RF) 2.select the inoculants that survived best, and 3. test whether LAB silage inoculants produce bacteriocins-like substances. The most promising strains will be used in the next steps of the research. Silage inoculants containing LAB are used in order to improve forage preservation efficiency. In addition, silage inoculants enhance animal performance in many cases. This includes improvements in feed intake, liveweight gain and milk production in 25-40% of studies reviewed. The cause for the improvement in animal performance is not clear but appears to be other than direct effect of LAB inoculants on silage fermentation. Results from various studies suggest a possible probiotic effect. Our hypothesis is that specific LAB strains interact with rumen microorganisms which results in enhanced rumen functionality and animal performance. The first step of the research is to determine whether LAB of silage inoculants survive in RF. Silage inoculants (12 in the U.S. and 10 in Israel) were added to clarified and strained RF. Inoculation rate was 10 ⁶ (clarified RF), 10⁷ (strained RF) (in the U.S.) and 10⁷, 10⁸ CFU ml⁻¹ in Israel (strained RF). The inoculated RF was incubated for 72 and 96 h at 39°C, with and without 5 g 1⁻¹ glucose. Changes in pH, LAB numbers and fermentation products were monitored throughout the incubation period. The results indicated that LAB silage inoculants can survive in RF. The inoculants with the highest counts after 72 h incubation in rumen fluid were Lactobacillus plantarum MTD1 and a L. plantarum/P. cerevisiae mixture (USA) and Enterococcus faecium strains and Lactobacillus buchneri (Israel). Incubation of rumen fluid with silage LAB inoculants resulted in higher pH values in most cases as compared with that of un-inoculated controls. The magnitude of the effect varied among inoculants and typically was enhanced with the inoculants that survived best. This might suggest the mode of action of LAB silage inoculants in the rumen as higher pH enhances fibrolytic microorganisms in the rumen. Volatile fatty acid (VFA) concentrations in the inoculated RF tended to be lower than in the control RF after incubation. However, L. plalltarull1 MTDI resulted in the highest concentrations of VFA in the RF relative to other inoculants. The implication of this result is not as yet clear. In previous research by others, feeding silages which were inoculated with this strain consistently enhanced animal performance. These finding were recently published in Weinberg et.al.. (2003), J. of Applied Microbiology 94:1066-1071 and in Weinberg et al.. (2003), Applied Biochemistry and Biotechnology (accepted). In addition, some strains in our studies have shown bacteriocins like activity. These included Pediococcus pentosaceus, Enterococcus faecium and Lactobacillus plantarum Mill 1. These results will enable us to continue the research with the LAB strains that survived best in the rumen fluid and have the highest potential to affect the rumen environment.
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Solberg, Thomas. Aspects of anuran metabolism : effects of chronic hypoxia on maximal oxygen uptake rates and the fate of lactic acid. Portland State University Library, styczeń 2000. http://dx.doi.org/10.15760/etd.3215.

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Olson, Edwin S. Task 2.0 - Air Quality Assessment, Control, and Analytical Methods Subtask 2.11 - Lactic Acid FGD Additives From Sugar Beet Wastewater. Office of Scientific and Technical Information (OSTI), luty 1998. http://dx.doi.org/10.2172/1690.

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