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1

Genera and species in acetic acid bacteria.  

PubMed

Taxonomic studies of acetic acid bacteria were historically surveyed. The genus Acetobacter was first introduced in 1898 with a single species, Acetobacter aceti. The genus Gluconobacter was proposed in 1935 for strains with intense oxidation of glucose to gluconic acid rather than oxidation of ethanol to acetic acid and no oxidation of acetate. The genus "Acetomonas" was described in 1954 for strains with polar flagellation and no oxidation of acetate. The proposals of the two generic names were due to confusion, and "Acetomonas" was a junior subjective synonym of Gluconobacter. The genus Acetobacter was in 1984 divided into two subgenera, Acetobacter and Gluconoacetobacter. The latter was elevated to the genus Gluconacetobacter in 1998. In the acetic acid bacteria, ten genera are presently recognized and accommodated to the family Acetobacteraceae, the Alphaproteobacteria: Acetobacteer, Gluconobacter, Acidomonas, Gluconacetobacter, Asaia, Kozakia, Swaminathania, Saccharibacter, Neoasaia and Granulibacter. In contrast, the genus Frateuria, strains of which were once named 'pseudacetic acid bacteria', was classified into the Gammaproteobacteria. The genus Gluconacetobacter was phylogenetically divided into two groups: the Gluconacetobacter liquefaciens group and the Gluconacetobacter xylinus group. The two groups were discussed taxonomically. PMID:18199517

Yamada, Yuzo; Yukphan, Pattaraporn

2007-12-05

2

Organisms Associated with Acetic Acid Bacteria in Vinegar Production  

Microsoft Academic Search

Vinegars are the product of scalar fermentations carried out by several groups of microorganisms acting at different moments\\u000a in time. The initial phase is generally represented by an alcoholic fermentation commonly carried out by yeasts. Lactic acid\\u000a bacteria (LAB) can also play a role in releasing ethanol and acetic acid from heterofermentative lactic acid fermentations.\\u000a Depending on the nature of

Sandra Rainieri; Carlo Zambonelli

3

Acetic acid bacteria spoilage of bottled red wine -- a review.  

PubMed

Acetic acid bacteria (AAB) are ubiquitous organisms that are well adapted to sugar and ethanol rich environments. This family of Gram-positive bacteria are well known for their ability to produce acetic acid, the main constituent in vinegar. The oxidation of ethanol through acetaldehyde to acetic acid is well understood and characterised. AAB form part of the complex natural microbial flora of grapes and wine, however their presence is less desirable than the lactic acid bacteria and yeast. Even though AAB were described by Pasteur in the 1850s, wine associated AAB are still difficult to cultivate on artificial laboratory media and until more recently, their taxonomy has not been well characterised. Wine is at most risk of spoilage during production and the presence of these strictly aerobic bacteria in grape must and during wine maturation can be controlled by eliminating, or at least limiting oxygen, an essential growth factor. However, a new risk, spoilage of wine by AAB after packaging, has only recently been reported. As wine is not always sterile filtered prior to bottling, especially red wine, it often has a small resident bacterial population (<10(3) cfu/mL), which under conducive conditions might proliferate. Bottled red wines, sealed with natural cork closures, and stored in a vertical upright position may develop spoilage by acetic acid bacteria. This spoilage is evident as a distinct deposit of bacterial biofilm in the neck of the bottle at the interface of the wine and the headspace of air, and is accompanied with vinegar, sherry, bruised apple, nutty, and solvent like off-aromas, depending on the degree of spoilage. This review focuses on the wine associated AAB species, the aroma and flavour changes in wine due to AAB metabolism, discusses the importance of oxygen ingress into the bottle and presents a hypothesis for the mechanism of spoilage of bottled red wine. PMID:18237809

Bartowsky, Eveline J; Henschke, Paul A

2007-12-23

4

Polyphasic taxonomy of acetic acid bacteria: An overview of the currently applied methodology  

Microsoft Academic Search

Acetic acid bacteria are Gram-negative, obligate aerobic bacteria that have the ability to incompletely oxidize alcohols or sugars to organic acids as end products. They are widespread in nature and most of them are capable to oxidize ethanol as substrate to acetic acid. This characteristic makes that acetic acid bacteria are often involved in foods and beverages, either in a

Ilse Cleenwerck; Paul De Vos

2008-01-01

5

Recent advances in nitrogen-fixing acetic acid bacteria.  

PubMed

Nitrogen is an essential plant nutrient, widely applied as N-fertilizer to improve yield of agriculturally important crops. An interesting alternative to avoid or reduce the use of N-fertilizers could be the exploitation of plant growth-promoting bacteria (PGPB), capable of enhancing growth and yield of many plant species, several of agronomic and ecological significance. PGPB belong to diverse genera, including Azospirillum, Azotobacter, Herbaspirillum, Bacillus, Burkholderia, Pseudomonas, Rhizobium, and Gluconacetobacter, among others. They are capable of promoting plant growth through different mechanisms including (in some cases), the biological nitrogen fixation (BNF), the enzymatic reduction of the atmospheric dinitrogen (N(2)) to ammonia, catalyzed by nitrogenase. Aerobic bacteria able to oxidize ethanol to acetic acid in neutral or acid media are candidates of belonging to the family Acetobacteraceae. At present, this family has been divided into ten genera: Acetobacter, Gluconacetobacter, Gluconobacter, Acidomonas, Asaia, Kozakia, Saccharibacter, Swaminathania, Neoasaia, and Granulibacter. Among them, only three genera include N(2)-fixing species: Gluconacetobacter, Swaminathania and Acetobacter. The first N(2)-fixing acetic acid bacterium (AAB) was described in Brazil. It was found inside tissues of the sugarcane plant, and first named as Acetobacter diazotrophicus, but then renamed as Gluconacetobacter diazotrophicus. Later, two new species within the genus Gluconacetobacter, associated to coffee plants, were described in Mexico: G. johannae and G. azotocaptans. A salt-tolerant bacterium named Swaminathania salitolerans was found associated to wild rice plants. Recently, N(2)-fixing Acetobacter peroxydans and Acetobacter nitrogenifigens, associated with rice plants and Kombucha tea, respectively, were described in India. In this paper, recent advances involving nitrogen-fixing AAB are presented. Their natural habitats, physiological and genetic aspects, as well as their association with different plants and contribution through BNF are described as an overview. PMID:18177965

Pedraza, Raúl O

2007-12-05

6

Effects of Acetic Acid on the Regrowth of Heterotrophic Bacteria in the Drinking Water Distribution System  

Microsoft Academic Search

Three laboratory-scale water pipe systems were set up to study the effects of adding two levels of acetic acid (10 and 50 ?g acetate eq-C l?1) on the bacterial regrowth in water pipes. The results of the water pipe test showed that nearly all carbon in the acetic acid could be readily utilized by bacteria and resulted in an increase

Chungsying Lu; Chenghwa Chu

2005-01-01

7

Application of molecular methods to demonstrate species and strain evolution of acetic acid bacteria population during wine production  

Microsoft Academic Search

The growth of acetic acid bacteria on grapes or throughout the winemaking process influences the quality of wine, mainly because it increases the volatile acidity. The objective of this study was to analyse how the acetic acid bacteria population evolves in the changing environment of the grape surface and during wine fermentation. We have analysed the influence of yeast inoculation

Ángel González; Núria Hierro; Montse Poblet; Albert Mas; José Manuel Guillamón

2005-01-01

8

Strain typing of acetic acid bacteria responsible for vinegar production by the submerged elaboration method  

Microsoft Academic Search

Strain typing of 103 acetic acid bacteria isolates from vinegars elaborated by the submerged method from ciders, wines and spirit ethanol, was carried on in this study. Two different molecular methods were utilised: pulsed field gel electrophoresis (PFGE) of total DNA digests with a number of restriction enzymes, and enterobacterial repetitive intergenic consensus (ERIC) – PCR analysis. The comparative study

Rocío Fernández-Pérez; Carmen Torres; Susana Sanz; Fernanda Ruiz-Larrea

2010-01-01

9

Alcohol dehydrogenase of acetic acid bacteria: structure, mode of action, and applications in biotechnology  

Microsoft Academic Search

Pyrroquinoline quinone-dependent alcohol dehydrogenase (PQQ-ADH) of acetic acid bacteria is a membrane-bound enzyme involved\\u000a in the acetic acid fermentation by oxidizing ethanol to acetaldehyde coupling with reduction of membranous ubiquinone (Q),\\u000a which is, in turn, re-oxidized by ubiquinol oxidase, reducing oxygen to water. PQQ-ADHs seem to have co-evolved with the organisms\\u000a fitting to their own habitats. The enzyme consists of

Toshiharu Yakushi; Kazunobu Matsushita

2010-01-01

10

Pentose oxidation by acetic Acid bacteria led to a finding of membrane-bound purine nucleosidase.  

PubMed

D-Ribose and 2-deoxy-D-ribose were oxidized to 4-keto-D-ribonate and 2-deoxy-4-keto-D-ribonate respectively by oxidative fermentation, and the chemical structures of the oxidation products were confirmed to be as expected. Both pentoses are important sugar components of nucleic acids. When examined, purine nucleosidase activity predominated in the membrane fraction of acetic acid bacteria. This is perhaps the first finding of membrane-bound purine nucleosidase. PMID:23649247

Adachi, Osao; Hours, Roque A; Akakabe, Yoshihiko; Shinagawa, Emiko; Ano, Yoshitaka; Yakushi, Toshiharu; Matsushita, Kazunobu

2013-05-07

11

Effect of different fertilization treatments on indole-3-acetic acid producing bacteria in soil  

Microsoft Academic Search

Purpose  Soil microorganisms directly affect the growth of plants. Especially, plant growth-promoting rhizobacteria (PGPR) play an\\u000a important role in plant growth. There are many studies about the effects of different fertilization treatments on soil microbial\\u000a community structure; however, the effects on PGPR, including indole-3-acetic acid (IAA)-producing bacteria have not been previously\\u000a reported. The objective of this study is to determine the

Chao-Lei Yuan; Cheng-Xiang Mou; Wen-Liang Wu; Yan-Bin Guo

2011-01-01

12

A PCR assay for detection of acetic acid-tolerant lactic acid bacteria in acidic food products.  

PubMed

A PCR assay for the detection of acetic acid-tolerant lactic acid bacteria in the genera of Lactobacillus and Pediococcus was developed in this study. Primers targeting the bacterial 16S rRNA gene were newly designed and used in this PCR assay. To determine the specificity of the assay, 56 different bacterial strains (of 33 genera), 2 fungi, 3 animals, and 4 plants were tested. Results were positive for most tested bacterial members of 16S rRNA gene-based phylogenetic groups (classified in the Lactobacillus casei and Pediococcus group), including Lactobacillus fructivorans, Lactobacillus brevis, Lactobacillus buchneri, Lactobacillus plantarum, and Lactobacillus paracasei. For all other bacterial strains and eukaryote tested, results were negative. Bacterial DNA for PCR was prepared with a simple procedure with the use of Chelex 100 resin from culture after growth in deMan Rogosa Sharpe broth (pH 6.0). To test this PCR assay for the monitoring of the acetic acid-tolerant lactic acid bacteria, L. fructivorans was inoculated into several acidic food as an indicator. Before the PCR, the inoculation of 10 to 50 CFU of bacteria per g of food was followed by a 28-h enrichment culture step, and the PCR assay allowed the detection of bacterial cells. Including the enrichment culture step, the entire PCR detection process can be completed within 30 h. PMID:15035383

Nakano, Shigeru; Matsumura, Atsushi; Yamada, Toshihiro

2004-03-01

13

The formation of acetic acid from carbon dioxide and hydrogen by anaerobic spore-forming bacteria  

Microsoft Academic Search

Summary Further experiments on an anaerobic bacillus synthesising acetic acid from CO2 and H2 are described. The organism in question was classified asClostridium aceticum n.sp. Acetic acid is also formed from sugar.

K. T. Wieringa

1939-01-01

14

Activity, distribution and function of indole-3-acetic acid biosynthetic pathways in bacteria.  

PubMed

The capacity to produce the phytohormone indole-3-acetic acid (IAA) is widespread among bacteria that inhabit diverse environments such as soils, fresh and marine waters, and plant and animal hosts. Three major pathways for bacterial IAA synthesis have been characterized that remove the amino and carboxyl groups from the ?-carbon of tryptophan via the intermediates indolepyruvate, indoleacetamide, or indoleacetonitrile; the oxidized end product IAA is typically secreted. The enzymes in these pathways often catabolize a broad range of substrates including aromatic amino acids and in some cases the branched chain amino acids. Moreover, expression of some of the genes encoding key IAA biosynthetic enzymes is induced by all three aromatic amino acids. The broad distribution and substrate specificity of the enzymes suggests a role for these pathways beyond plant-microbe interactions in which bacterial IAA has been best studied. PMID:22978761

Patten, Cheryl L; Blakney, Andrew J C; Coulson, Thomas J D

2012-09-15

15

Growth inhibitory effect of grape phenolics against wine spoilage yeasts and acetic acid bacteria.  

PubMed

This paper investigates the in vitro antimicrobial potential of 15 grape phenolic compounds of various chemical classes (phenolic acids, stilbenes and flavonoids) using the broth microdilution method against yeasts and acetic acid bacteria frequently occurring in deteriorated wine. Pterostilbene (MICs=32-128 ?g/mL), resveratrol (MICs=256-512 ?g/mL) and luteolin (MICs=256-512 ?g/mL) are among six active compounds that possessed the strongest inhibitory effects against all microorganisms tested. In the case of phenolic acids, myricetin, p-coumaric and ferulic acids exhibited selective antimicrobial activity (MICs=256-512 ?g/mL), depending upon yeasts and bacteria tested. In comparison with potassium metabisulphite, all microorganisms tested were more susceptible to the phenolics. The results revealed the antibacterial and antiyeast effects against wine spoilage microorganisms of several highly potent phenolics naturally occurring in grapes. These findings also provide arguments for further investigation of stilbenes as prospective compounds reducing the need for the use of sulphites in winemaking. PMID:23334100

Pastorkova, E; Zakova, T; Landa, P; Novakova, J; Vadlejch, J; Kokoska, L

2013-01-02

16

Utilization of Vinegar for Isolation of Cellulose Producing Acetic Acid Bacteria  

SciTech Connect

Wastes of traditionally fermented Turkish vinegar were used in the isolation of cellulose producing acetic acid bacteria. Waste material was pre-enriched in Hestrin-Schramm medium and microorganisms were isolated by plating dilution series on HS agar plates The isolated strains were subjected to elaborate biochemical and physiological tests for identification. Test results were compared to those of reference strains Gluconacetobacter xylinus DSM 46604, Gluconacetobacter hansenii DSM 5602 and Gluconacetobacter liquefaciens DSM 5603. Seventeen strains, out of which only three were found to secrete the exopolysaccharide cellulose. The highest cellulose yield was recorded as 0.263+-0.02 g cellulose L{sup -1} for the strain AS14 which resembled Gluconacetobacter hansenii in terms of biochemical tests.

Aydin, Y. Andelib; Aksoy, Nuran Deveci [Chemical Engineering Department of Istanbul Technical University, Ayazaga, Maslak, Istanbul, 34469 (Turkey)

2010-06-17

17

Utilization of Vinegar for Isolation of Cellulose Producing Acetic Acid Bacteria  

NASA Astrophysics Data System (ADS)

Wastes of traditionally fermented Turkish vinegar were used in the isolation of cellulose producing acetic acid bacteria. Waste material was pre-enriched in Hestrin-Schramm medium and microorganisms were isolated by plating dilution series on HS agar plates The isolated strains were subjected to elaborate biochemical and physiological tests for identification. Test results were compared to those of reference strains Gluconacetobacter xylinus DSM 46604, Gluconacetobacter hansenii DSM 5602 and Gluconacetobacter liquefaciens DSM 5603. Seventeen strains, out of which only three were found to secrete the exopolysaccharide cellulose. The highest cellulose yield was recorded as 0.263+/-0.02 g cellulose L-1 for the strain AS14 which resembled Gluconacetobacter hansenii in terms of biochemical tests.

Aydin, Y. Andelib; Aksoy, Nuran Deveci

2010-06-01

18

Structural analysis of fructans produced by acetic acid bacteria reveals a relation to hydrocolloid function.  

PubMed

Some strains of acetic acid bacteria (Gluconobacter frateurii TMW 2.767, Gluconobacter cerinus DSM 9533T, Neoasaia chiangmaiensis NBRC 101099, Kozakia baliensis DSM 14400) produce high amounts of fructans, which can be exploited in food applications as previously demonstrated empirically for dough systems. In order to get insight into the structure and functionality of these polymers, we investigated the fructans isolated from these strains with respect to their linkage types and molecular weights/shapes using NMR spectroscopy and AF4-MALS-RI. Each fructan was identified as levan. The isolated levan fractions were highly similar according to their basic linearity and linkage types, but differed significantly in terms of their individual molecular weight distributions. In aqueous solutions the size of levan molecules present in all isolated levans continuously increased with their molecular weight and they tended to adopt a more compact molecular shape. Our data suggest that the increasing molecular weight of a levan particle enforces intramolecular interactions to reach the structural compactness of a microgel with hydrocolloid properties. PMID:23399151

Jakob, Frank; Pfaff, Andre; Novoa-Carballal, Ramon; Rübsam, Heinrich; Becker, Thomas; Vogel, Rudi F

2012-10-29

19

Gluconobacter as well as Asaia species, newly emerging opportunistic human pathogens among acetic acid bacteria.  

PubMed

Acetic acid bacteria (AAB) are broadly used in industrial food processing. Among them, members of the genera Asaia, Acetobacter, and Granulibacter were recently reported to be human opportunistic pathogens. We isolated AAB from clinical samples from three patients and describe here the clinical and bacteriological features of these cases. We report for the first time (i) the isolation of a Gluconobacter sp. from human clinical samples; (ii) the successive isolation of different AAB, i.e., an Asaia sp. and two unrelated Gluconobacter spp., from a cystic fibrosis patient; and (iii) persistent colonization of the respiratory tract by a Gluconobacter sp. in this patient. We reviewed the main clinical features associated with AAB isolation identified in the 10 documented reports currently available in the literature. Albeit rare, infections as well as colonization with AAB are increasingly reported in patients with underlying chronic diseases and/or indwelling devices. Clinicians as well as medical microbiologists should be aware of these unusual opportunistic pathogens, which are difficult to detect during standard medical microbiological investigations and which are multiresistant to antimicrobial agents. Molecular methods are required for identification of genera of AAB, but the results may remain inconclusive for identification to the species level. PMID:20826638

Alauzet, Corentine; Teyssier, Corinne; Jumas-Bilak, Estelle; Gouby, Anne; Chiron, Raphael; Rabaud, Christian; Counil, François; Lozniewski, Alain; Marchandin, Hélène

2010-09-08

20

Gluconobacter as Well as Asaia Species, Newly Emerging Opportunistic Human Pathogens among Acetic Acid Bacteria ? †  

PubMed Central

Acetic acid bacteria (AAB) are broadly used in industrial food processing. Among them, members of the genera Asaia, Acetobacter, and Granulibacter were recently reported to be human opportunistic pathogens. We isolated AAB from clinical samples from three patients and describe here the clinical and bacteriological features of these cases. We report for the first time (i) the isolation of a Gluconobacter sp. from human clinical samples; (ii) the successive isolation of different AAB, i.e., an Asaia sp. and two unrelated Gluconobacter spp., from a cystic fibrosis patient; and (iii) persistent colonization of the respiratory tract by a Gluconobacter sp. in this patient. We reviewed the main clinical features associated with AAB isolation identified in the 10 documented reports currently available in the literature. Albeit rare, infections as well as colonization with AAB are increasingly reported in patients with underlying chronic diseases and/or indwelling devices. Clinicians as well as medical microbiologists should be aware of these unusual opportunistic pathogens, which are difficult to detect during standard medical microbiological investigations and which are multiresistant to antimicrobial agents. Molecular methods are required for identification of genera of AAB, but the results may remain inconclusive for identification to the species level.

Alauzet, Corentine; Teyssier, Corinne; Jumas-Bilak, Estelle; Gouby, Anne; Chiron, Raphael; Rabaud, Christian; Counil, Francois; Lozniewski, Alain; Marchandin, Helene

2010-01-01

21

Acetate oxidation to CO 2 in anaerobic bacteria via a novel pathway not involving reactions of the citric acid cycle  

Microsoft Academic Search

In several sulfate-reducing bacteria capable of complete oxidation of acetate (or acetyl CoA), the citric acid cycle is not operative. No 2-oxoglutarate dehydrogenase activity was found in these organisms, and the labelling pattern of oxaloacetate excludes its synthesis via 2-oxo-glutarate. These sulfate-reducers contained, however, high activities of the enzymes carbon monoxide dehydrogenase and formate dehydrogenase and catalyzed an isotope exchange

Rolf Schauder; Bernhard Eikmanns; Rudolf K. Thauer; Fritz Widdel; Georg Fuchs

1986-01-01

22

A lytic enzyme cocktail from Streptomyces sp. B578 for the control of lactic and acetic acid bacteria in wine.  

PubMed

Beside yeasts, lactic acid bacteria (LAB) are the most abundant microbes in must during vinification. Whereas Oenococcos oeni is commercially used as a starter culture for the biological acid reduction in wines, other species are responsible for different types of wine spoilage. Members of the genera Pediococcus, Weissella, Leuconostoc, and Lactobacillus are producers of exopolysaccharide slimes, biogenic amines, acetic acid, and other off-flavors. In order to control microbial growth, different procedures such as heating of must and addition of sulfite or lysozyme from egg white are generally applied. Yet, because of health risks, the application of sulfite should be reduced and lysozyme is not effective against all LAB. In this study, we describe exoenzymes from a Streptomyces sp. strain B578 lysing nearly all wine-relevant strains of LAB and Gram-negative acetic acid bacteria. The lytic enzymes were active under wine-making conditions, such as the presence of sulfite and ethanol, low temperatures, and low pH values. The analysis of the exoenzyme composition revealed a synergistic action of different cell wall hydrolases. In conclusion, the lytic cocktail of Streptomyces sp. B578 is a promising tool for the control of wine-spoiling bacteria. PMID:19277643

Blättel, V; Wirth, K; Claus, H; Schlott, B; Pfeiffer, P; König, H

2009-03-10

23

Molecular Structure of Acetic acid  

NSDL National Science Digital Library

Acetic Acid commonly associated with vinegar; it is the most commercially important organic acid and is used to manufacture a wide range of chemical products, such as plastics and insecticides. Acetic acid is produced naturally by Aceto bacteria but, except for making vinegar, is usually made through synthetic processes. Ethanoic acid is used as herbicide, as a micro-biocide, as a fungicide and for pH adjustment.

2003-06-02

24

Aromatic amino acid aminotransferase activity and indole-3-acetic acid production by associative nitrogen-fixing bacteria  

Microsoft Academic Search

In this work, we report the detection of aromatic amino acid aminotransferase (AAT) activity from cell-free crude extracts of nine strains of N2-fixing bacteria from three genera. Using tyrosine as substrate, AAT activity ranged in specific activity from 0.084 to 0.404 ?molmin?1mg?1. When analyzed under non-denaturating PAGE conditions; and using tryptophan, phenylalanine, tyrosine, and histidine as substrates Pseudomonas stutzeri A15

Ma. Luisa Xiqui; Beatriz Eugenia Baca

2004-01-01

25

Genus-specific profile of acetic acid bacteria by 16S rDNA PCR-DGGE.  

PubMed

An effective method for grouping acetic acid bacteria (AAB) genera was defined and evaluated as a tool for preliminary screening of the major AAB species involved in vinegar production. Acetobacter, Gluconobacter, Gluconacetobacter, Asaia, Neoasaia, Saccharibacter, Frateuria and Kozakia AAB strains were screened on the basis of the 16S rDNA sequences using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) technique. The DGGE profile of all the strains tested, consisted of one single band of approximately 330 bp for each strain and allowed their clustering. The results obtained clearly reflected in silico phylogenetic analysis of the AAB species used in this study, in fact, the species with a higher 16S rDNA sequence homology showed a similar electrophoretic profile. In particular almost all the species belonging to the genus Gluconacetobacter showed a DGGE pattern nearly identical and well distinct from all the other AAB genera. Furthermore by PCR-DGGE it was possible to clearly group the species more frequently recovered from vinegar fermentation which are mainly distributed in the genera Acetobacter, Gluconobacter and Gluconacetobacter. PMID:17919758

De Vero, Luciana; Giudici, Paolo

2007-09-04

26

Occurrence of enzymes involved in biosynthesis of indole-3-acetic acid from indole-3-acetonitrile in plant-associated bacteria, Agrobacterium and Rhizobium.  

PubMed Central

The occurrence of a hitherto unknown pathway involving the action of two enzymes, a nitrile hydratase and an amidase for the biosynthesis of indole-3-acetic acid was discovered in phytopathogenic bacteria Agrobacterium tumefaciens and in leguminous bacteria Rhizobium. The nitrile hydratase acting on indole-3-acetonitrile was purified to homogeneity through only two steps from the cell-free extract of A. tumefaciens. The molecular mass of the purified enzyme estimated by HPLC was about 102 kDa, and the enzyme consisted of four subunits identical in molecular mass. The enzyme exhibited a broad absorption spectrum in the visible range with absorption maxima at 408 nm and 705 nm, and it contained cobalt and iron. The enzyme stoichiometrically catalyzed the hydration of indole-3-acetonitrile into indole-3-acetamide with a specific activity of 13.7 mol per min per mg and a Km of 7.9 microM. Images Fig. 1

Kobayashi, M; Suzuki, T; Fujita, T; Masuda, M; Shimizu, S

1995-01-01

27

Metabolic Activity of Fatty Acid-Oxidizing Bacteria and the Contribution of Acetate, Propionate, Butyrate, and CO2 to Methanogenesis in Cattle Waste at 40 and 60?C  

PubMed Central

The quantitative contribution of fatty acids and CO2 to methanogenesis was studied by using stirred, 3-liter bench-top digestors fed on a semicontinuous basis with cattle waste. The fermentations were carried out at 40 and 60°C under identical loading conditions (6 g of volatile solids per liter of reactor volume per day, 10-day retention time). In the thermophilic digestor, acetate turnover increased from a prefeeding level of 16 ?M/min to a peak (49 ?M/min) 1 h after feeding and then gradually decreased. Acetate turnover in the mesophilic digestor increased from 15 to 40 ?M/min. Propionate turnover ranged from 2 to 5.2 and 1.5 to 4.5 ?M/min in the thermophilic and mesophilic digestors, respectively. Butyrate turnover (0.7 to 1.2 ?M/min) was similar in both digestors. The proportion of CH4 produced via the methyl group of acetate varied with time after feeding and ranged from 72 to 75% in the mesophilic digestor and 75 to 86% in the thermophilic digestor. The contribution from CO2 reduction was 24 to 29% and 19 to 27%, respectively. Propionate and butyrate turnover accounted for 20% of the total CH4 produced. Acetate synthesis from CO2 was greatest shortly after feeding and was higher in the thermophilic digestor (0.5 to 2.4 ?M/min) than the mesophilic digestor (0.3 to 0.5 ?M/min). Counts of fatty acid-degrading bacteria were related to their turnover activity.

Mackie, Roderick I.; Bryant, Marvin P.

1981-01-01

28

Quick identification of acetic acid bacteria based on nucleotide sequences of the 16S–23S rDNA internal transcribed spacer region and of the PQQ-dependent alcohol dehydrogenase gene  

Microsoft Academic Search

Acetic acid bacteria (AAB) are well known for oxidizing different ethanol-containing substrates into various types of vinegar. They are also used for production of some biotechnologically important products, such as sorbose and gluconic acids. However, their presence is not always appreciated since certain species also spoil wine, juice, beer and fruits. To be able to follow AAB in all these

Janja Trcek

2005-01-01

29

Indole-3-acetic acid (IAA) production in symbiotic and non-symbiotic nitrogen-fixing bacteria and its optimization by Taguchi design.  

PubMed

Production of Indole-3-acetic acid (IAA) in 35 different symbiotic and non-symbiotic nitrogen-fixing bacteria strains isolated from soil and plant roots was studied and assayed by chromatography and colorimetric methods. These bacteria included Agrobacterium, Paenibacillus, Rhizobium, Klebsiella oxytoca, and Azotobacter. The best general medium and synergism effects of isolates for IAA production were investigated. Effects of different variables containing physical parameters and key media components and optimization of condition for IAA production were performed using the Design of Experiments. Qualitek-4 (W32b) software for automatic design and analysis of the experiments, both based on Taguchi method was used. The results showed that Rhizobium strains, symbiotic, and Paenibacillus non-symbiotic bacteria yielded the highest concentrations of IAA (in the range of 5.23-0.27 and 4.90-0.19 ppm IAA/mg biomass, respectively) and IAA production was increased by synergism effect of them. Yeast Extract Mannitol medium supplemented with L-tryptophan was the best general medium for IAA production. The analysis of experimental data using Taguchi method indicated that nitrogen source is very prominent variable in affecting the yield and mannitol as carbon source, potassium nitrate (1%), and L-tryptophan (3 g/l) as nitrogen sources after 72-h incubation at 30 degrees C were the optimum conditions for production of IAA. 5.89 ppm IAA/mg biomass was produced under these optimal conditions. PMID:20526603

Shokri, Dariush; Emtiazi, Giti

2010-06-05

30

Acetobacter aceti Possesses a Proton Motive Force-Dependent Efflux System for Acetic Acid  

Microsoft Academic Search

Acetic acid bacteria are obligate aerobes able to oxidize ethanol, sugar alcohols, and sugars into their corresponding acids. Among them, Acetobacter and Gluconacetobacter species have very high ethanol oxidation capacity, leading to accumulation of vast amounts of acetic acid outside the cell. Since these bacteria are able to grow in media with high concentrations of acetic acid, they must possess

Kazunobu Matsushita; Taketo Inoue; Osao Adachi; Hirohide Toyama

2005-01-01

31

Anaerobic thermophilic fermentation for acetic acid production from milk permeate  

Microsoft Academic Search

Fermentation of milk permeate to produce acetic acid under anaerobic thermophilic conditions (?60°C) was studied. Although none of the known thermophilic acetogenic bacteria can ferment lactose, it has been found that one strain can use galactose and two strains can use lactate. Moorella thermoautotrophica DSM 7417 and M. thermoacetica DSM 2955 were able to convert lactate to acetate at thermophilic

Mylène Talabardon; Jean-Paul Schwitzguébel; Paul Péringer

2000-01-01

32

Cytenamide acetic acid solvate  

PubMed Central

In the crystal structure of the title compound (systematic name: 5H-dibenzo[a,d]cyclo­hepta­triene-5-carboxamide ethanoic acid solvate), C16H13NO·C2H4O2, the cytenamide and solvent mol­ecules form a hydrogen-bonded R 2 2(8) dimer motif, which is further connected to form a centrosymmetric double ring motif arrangement. The cycloheptene ring adopts a boat conformation and the dihedral angle between the least-squares planes through the two aromatic rings is 54.7?(2)°.

Johnston, Andrea; Florence, Alastair J.; Fabianni, Francesca J. A.; Shankland, Kenneth; Bedford, Colin T.

2008-01-01

33

Cytenamide acetic acid solvate.  

PubMed

IN THE CRYSTAL STRUCTURE OF THE TITLE COMPOUND (SYSTEMATIC NAME: 5H-dibenzo[a,d]cyclo-hepta-triene-5-carboxamide ethanoic acid solvate), C(16)H(13)NO·C(2)H(4)O(2), the cytenamide and solvent mol-ecules form a hydrogen-bonded R(2) (2)(8) dimer motif, which is further connected to form a centrosymmetric double ring motif arrangement. The cycloheptene ring adopts a boat conformation and the dihedral angle between the least-squares planes through the two aromatic rings is 54.7?(2)°. PMID:21202682

Johnston, Andrea; Florence, Alastair J; Fabianni, Francesca J A; Shankland, Kenneth; Bedford, Colin T

2008-05-30

34

Contribution of acetate to butyrate formation by human faecal bacteria  

Microsoft Academic Search

Acetate is normally regarded as an endproduct of anaerobic fermentation, but butyrate-producing bacteria found in the human colon can be net utilisers of acetate. The butyrate formed provides a fuel for epithelial cells of the large intestine and influences colonic health. (1-13C)Acetate was used to investigate the contribution of exogenous acetate to butyrate formation. Faecalibacterium prausnitzii and Roseburia spp. grown

Sylvia H. Duncan; Grietje Holtrop; Gerald E. Lobley; A. Graham Calder; Colin S. Stewart; Harry J. Flint

2004-01-01

35

A Specialized Citric Acid Cycle Requiring Succinyl-Coenzyme A (CoA):Acetate CoA-Transferase (AarC) Confers Acetic Acid Resistance on the Acidophile Acetobacter aceti  

Microsoft Academic Search

Microbes tailor macromolecules and metabolism to overcome specific environmental challenges. Acetic acid bacteria perform the aerobic oxidation of ethanol to acetic acid and are generally resistant to high levels of these two membrane-permeable poisons. The citric acid cycle (CAC) is linked to acetic acid resistance in Acetobacter aceti by several observations, among them the oxidation of acetate to CO2 by

Elwood A. Mullins; Julie A. Francois; T. Joseph Kappock

2008-01-01

36

Orchid-associated bacteria produce indole-3-acetic acid, promote seed germination, and increase their microbial yield in response to exogenous auxin  

Microsoft Academic Search

Germination of orchid seeds is a complex process. In this paper we focus on interactions between the host-plant and its bacterial\\u000a partners via indole-3-acetic acid (IAA). Originally isolated from the roots of the epiphytic orchid Dendrobium moschatum, the strains of Rhizobium, Microbacterium, Sphingomonas, and Mycobacterium genera were among the most active IAA producers. Addition of exogenous tryptophan significantly enhanced auxin

Elena A. Tsavkelova; Tatiana A. Cherdyntseva; Svetlana Yu. Klimova; Andrey I. Shestakov; Svetlana G. Botina; Alexander I. Netrusov

2007-01-01

37

Carbohydrate metabolism in lactic acid bacteria  

Microsoft Academic Search

The term “lactic acid bacteria” is discussed. An overview of the following topics is given: main pathways of homo- and heterofermentation of hexoses, i.e. glycolysis, bifidus pathway, 6-phosphogluconate pathway; uptake and dissimilation of lactose (tagatose pathway); fermentation of pentoses and pentitols; alternative fates of pyruvate, i.e. splitting to formate and acetate, CO2 and acetate or formation of acetoin and diacetyl;

Otto Kandler

1983-01-01

38

Anaerobic thermophilic fermentation for acetic acid production from milk permeate.  

PubMed

Fermentation of milk permeate to produce acetic acid under anaerobic thermophilic conditions (approximately 60 degrees C) was studied. Although none of the known thermophilic acetogenic bacteria can ferment lactose, it has been found that one strain can use galactose and two strains can use lactate. Moorella thermoautotrophica DSM 7417 and M. thermoacetica DSM 2955 were able to convert lactate to acetate at thermophilic temperatures with a yield of approximately 0.93 g g(-1). Among the strains screened for their abilities to produce acetate and lactate from lactose, Clostridium thermolacticum DSM 2910 was found precisely to produce large amounts of lactate and acetate. However, it also produced significant amounts of ethanol, CO2 and H2. The lactate yield was affected by cell growth. During the exponential phase, acetate, ethanol, CO2 and H2 were the main products of fermentation with an equimolar acetate/ethanol ratio, whereas during the stationary phase, only lactic acid was produced with a yield of 4 mol per mol lactose, thus reaching the maximal theoretical value. When this bacterium was co-cultured with M. thermoautotrophica, lactose was first converted mainly to lactic acid, then to acetic acid, with a zero residual lactic acid concentration and an overall yield of acetate around 80%. Under such conditions, only 13% of the fermented lactose was converted to ethanol by C. thermolacticum. PMID:10784299

Talabardon, M; Schwitzguébel, J P; Péringer, P

2000-01-01

39

Investigation on isobaric vapor–liquid equilibrium for acetic acid + water + methyl ethyl ketone + isopropyl acetate  

Microsoft Academic Search

Isobaric vapor–liquid equilibrium (VLE) data for acetic acid+water, acetic acid+methyl ethyl ketone (MEK), MEK+isopropyl acetate, acetic acid+MEK+water and acetic acid+MEK+isopropyl acetate+water are measured at 101.33kPa using a modified Rose cell. The nonideal behavior in vapor phase of binary systems measured in this work is analyzed through calculating fugacity coefficients since mixture containing acetic acid deviates from ideal behavior seriously in

Qiang Xie; Hui Wan; MingJuan Han; GuoFeng Guan

2009-01-01

40

New process for producing cellulose acetate from wood in concentrated acetic acid  

Microsoft Academic Search

To explore further potential applications of acetic acid pulp, an investigation was conducted to develop a direct method for producing cellulose acetate from wood in combination with atmospheric acetic acid pulping. The process consists of delignification, totally chlorine-free bleaching, and esterification, with the concentrated acetic acid aqueous solution being used as only solvent throughout the process. The acetic acid pulp

Hironori Sato; Yasumitsu Uraki; Takao Kishimoto; Yoshihiro Sano

2003-01-01

41

REMOVAL OF ACETIC ACID IMPURITIES FROM ETHYL ACETATE BY ADSORPTION ON ION EXCHANGE RESINS  

Microsoft Academic Search

Removal of acetic acid impurities from ethyl acetate was attempted by sorption on basic ion-exchange resins. Kinetic studies showed that acid removal is controlled by intraparticle resistance from both ethyl acetate and alcohol. Breakthrough curves for uptake of the acid from ethyl acetate were obtained at different flow rates and concentrations. Desorption studies were performed using both ethyl acetate and

H. M. Anasthas; V. G. Gaikar

2001-01-01

42

Disinfection of mung bean seed with gaseous acetic acid.  

PubMed

Mung bean seed inoculated with Salmonella Typhimurium, Escherichia coli O157:H7, and Listeria monocytogenes (3 to 5 log CFU/g) was exposed to gaseous acetic acid in an aluminum fumigation chamber. Salmonella Typhimurium and E. coli O157:H7 were not detected by enrichment of seeds treated with 242 microl of acetic acid per liter of air for 12 h at 45 degrees C. L. monocytogenes was recovered by enrichment from two of 10 25-g seed samples treated in this manner. Fumigation with gaseous acetic acid was also lethal to indigenous bacteria and fungi on mung bean seed. The treatment did not significantly reduce seed germination rates, and no differences in surface microstructure were observed between treated and untreated seed viewed by scanning electron microscopy. PMID:10456753

Delaquis, P J; Sholberg, P L; Stanich, K

1999-08-01

43

Effects of Acetic Acid Pretreatment and Hot Air Drying on Resistance of Salmonella on Cabbage Slices  

Microsoft Academic Search

The heat resistance of Salmonella anatum inoculated onto the surface of cabbage slices as affected by acetic acid pretreatment (0.5–1.5% v\\/v) and hot air drying at 50–60°C was investigated. Approximately 1.5 log10 of Salmonella numbers was reduced after soaking the vegetables in acetic acid solution. The inhibitory effect of acetic acid on the bacteria was more pronounced during drying. The heat

Naphaporn Chiewchan; Pornpen Morakotjinda

2009-01-01

44

Delignification of Bagasse with Acetic Acid and Ozone. Part 1. Acetic Acid Pulping  

Microsoft Academic Search

Two-stage delignification of sugarcane bagasse with acetic acid and ozone was investigated. The better pulp was obtained pulping bagasse in aqueous solution of acetic acid (80% volume) at 145°C during 60 min. The liquor\\/bagasse ratio (L\\/B) was 10:1 and the kappa number was 44; it fell to 10 in the ozone stage due to selectivity of acetic acid medium. Pulp

H. Contreras Q; Z. A. Nagieb; R. Sanjuán D

1997-01-01

45

Quick identification of acetic acid bacteria based on nucleotide sequences of the 16S-23S rDNA internal transcribed spacer region and of the PQQ-dependent alcohol dehydrogenase gene.  

PubMed

Acetic acid bacteria (AAB) are well known for oxidizing different ethanol-containing substrates into various types of vinegar. They are also used for production of some biotechnologically important products, such as sorbose and gluconic acids. However, their presence is not always appreciated since certain species also spoil wine, juice, beer and fruits. To be able to follow AAB in all these processes, the species involved must be identified accurately and quickly. Because of inaccuracy and very time-consuming phenotypic analysis of AAB, the application of molecular methods is necessary. Since the pairwise comparison among the 16S rRNA gene sequences of AAB shows very high similarity (up to 99.9%) other DNA-targets should be used. Our previous studies showed that the restriction analysis of 16S-23S rDNA internal transcribed spacer region is a suitable approach for quick affiliation of an acetic acid bacterium to a distinct group of restriction types and also for quick identification of a potentially novel species of acetic acid bacterium (Trcek & Teuber 2002; Trcek 2002). However, with the exception of two conserved genes, encoding tRNAIle and tRNAAla, the sequences of 16S-23S rDNA are highly divergent among AAB species. For this reason we analyzed in this study a gene encoding PQQ-dependent ADH as a possible DNA-target. First we confirmed the expression of subunit I of PQQ-dependent ADH (AdhA) also in Asaia, the only genus of AAB which exhibits little or no ADH-activity. Further we analyzed the partial sequences of adhA among some representative species of the genera Acetobacter, Gluconobacter and Gluconacetobacter. The conserved and variable regions in these sequences made possible the construction of A. acetispecific oligonucleotide the specificity of which was confirmed in PCR-reaction using 45 well-defined strains of AAB as DNA-templates. The primer was also successfully used in direct identification of A. aceti from home made cider vinegar as well as for revealing the misclassification of strain IFO 3283 into the species A. aceti. PMID:16261863

Trcek, Janja

2005-10-01

46

Acetate as a carbon source for hydrogen production by photosynthetic bacteria  

Microsoft Academic Search

Hydrogen is a clean energy alternative to fossil fuels. Photosynthetic bacteria produce hydrogen from organic compounds by an anaerobic light-dependent electron transfer process. In the present study hydrogen production by three photosynthetic bacterial strains (Rhodopseudomonas sp., Rhodopseudomonas palustris and a non-identified strain), from four different short-chain organic acids (lactate, malate, acetate and butyrate) was investigated. The effect of light intensity

Maria J Barbosa; Jorge M. S Rocha; Johannes Tramper; René H Wijffels

2001-01-01

47

The PVT Properties of Acetic Acid.  

National Technical Information Service (NTIS)

The PVT properties of acetic acid in the saturated and single-phase regions were measured at temperatures between 448.15 and 603.15 K, at pressures up to about 10 MPa. The experimental results were corrected for decomposition of the sample.

D. A. Lee G. B. Lewis I. J. Lawrenson

1977-01-01

48

Factors Affecting Organic Acid Production by Sourdough (San Francisco) Bacteria  

PubMed Central

Previous workers from this laboratory observed considerable variation in the proportions of acetic and lactic acids produced in pure broth culture as compared to consistently high proportions of acetic acid produced in the sourdough and flour suspension systems. In the latter the proportion of acetic acid was always in the range of 20 to 35% of the total, whereas in pure broth culture frequently less than 5% acetic acid was produced. In the natural environment, the sourdough bacteria, tentatively identified as lactobacilli, coexist with a yeast, Saccharomyces exiguus, and this study was undertaken to determine whether this yeast or flour ingredients including glucose or other factors were involved in this variable production of acetic acid. The proportion of acetic acid produced in broth culture on maltose, the preferred carbohydrate source, was found to depend almost entirely on the degree of aeration. Essentially anaerobic conditions, as obtained by thorough evacuation and flushing with CO2 or N2, resulted in very low (5% or less) proportions of acetic acid. Aerobic conditions, achieved by continuous shaking in cotton-plugged flasks, yielded high levels (23 to 39% of the total) of acetic acid. Similar effects of aeration were observed with glucose as the substrate, although growth was considerably slower, or in nonsterile flour suspension systems. It is theorized that, under aerobic conditions, the reduced pyridine nucleotides generated in the dissimilation of carbohydrate are oxidized directly by molecular oxygen, thereby becoming unavailable for the reduction of the acetyl phosphate intermediate to ethyl alcohol, the usual product of anaerobic dissimilation of glucose by heterofermentative lactic acid bacteria. Comparative studies with known strains of homo- and heterofermentative lactobacilli showed similar effects of aeration only on the heterofermentative strains, lending additional support to the tentative grouping by previous workers from this laboratory of the sourdough bacteria with the heterofermentative lactobacilli.

Ng, Henry

1972-01-01

49

Dissimilatory Amino Acid Metabolism in Human Colonic Bacteria  

Microsoft Academic Search

The abilities of slurries of human faecal bacteria to ferment 20 different amino acids were investigated in batch culture incubations. Ammonia, short chain fatty acids, and in some cases, amines, were the principal products of dissimilatory metabolism. The types of SCFA produced were dependent on the chemical compositions of the test substrates. Thus, acetate and butyrate were formed from the

E. A Smith; G. T Macfarlane

1997-01-01

50

Hybrid reactive distillation systems for n-butyl acetate production from dilute acetic acid  

Microsoft Academic Search

The recovery of dilute acetic acid, regarding as a waste stream in many chemical and petrochemical processes, becomes an important issue due to economic and environmental awareness. In this work, a simulation study on the direct utilization of dilute acetic acid to produce n-butyl acetate via esterification with butanol in a reactive distillation is presented by using Aspen Plus. The

Amornchai Arpornwichanop; Kittipong Koomsup; Suttichai Assabumrungrat

2008-01-01

51

Kinetics of Ethyl Acetate Synthesis Catalyzed by Acidic Resins  

ERIC Educational Resources Information Center

|A low-cost experiment to carry out the second-order reversible reaction of acetic acid esterification with ethanol to produce ethyl acetate is presented to illustrate concepts of kinetics and reactor modeling. The reaction is performed in a batch reactor, and the acetic acid concentration is measured by acid-base titration versus time. The…

Antunes, Bruno M.; Cardoso, Simao P.; Silva, Carlos M.; Portugal, Ines

2011-01-01

52

Acetic acid vapor levels associated with facial prosthetics  

SciTech Connect

The use of Silastic Medical Adhesive Type A in the fabrication of facial prostheses may cause health hazards to the patient and the operator because of acetic acid emissions. Caution must be exercised to remove acetic acid vapors from the air and unliberated acetic acid from material applied directly to the skin.

McElroy, T.H.; Guerra, O.N.; Lee, S.A.

1985-01-01

53

Separating acetic acid from furol (furfural) by electrodialysis method  

SciTech Connect

Furfural production by hydrolysis of fibrous plant materials is accompanied by formation of acetic acid in amounts depending on the material used. The amount of acetic formed in the hydrolysis of the fruit shell of oil-tea camellia (Camellia oleosa) (an oilseed-bearing tree) is equal to the amount of furfural. The acetic acid can be separated from the furfural and concentrated to 10% by electrodialysis. A smaller amount of furfural is separated with acetic acid.

Guan, S.F.; Li, C.S. Ye, S.T.; Shen, S.Y.; Wang, Y.T.; Yu, S.H.

1981-01-01

54

Recovery of very dilute acetic acid using ion exchange  

SciTech Connect

Acetic and related acids occur in many industrial wastewaters, often mixed with several other classes of organic compounds. Acetic acid can be recovered from 1% solutions using weakly basic ion exchange resins. The acid is adsorbed by the free-base form of the resin, which can then be eluted using a slurry of lime to give a solution of calcium acetate. This solution could either be evaporated to crystallize calcium acetate or reacted with sulfuric acid to form acetic acid and gypsum. Laboratory tests of the proposed process gave product solutions of 15--20% acetic acid using pure 1% acetic acid as feed. Some measurements using a typical industrial effluent gave similar recoveries and showed that there was no initial fouling of the resins.

Cloete, F.L.D.; Marais, A.P. [Univ. of Stellenbosch (South Africa). Dept. of Chemical Engineering

1995-07-01

55

[Degradation of oxytetracycline with ozonation in acetic acid solvent].  

PubMed

Use acetic acid as the media of ozone degradation of oxytetracycline (OTC), and effects of the initial dosing ratio of ozone/OTC, ozone flow, free radical scavenger, metal ions on the removal rate of OTC were investigated respectively. The results showed that acetic acid had a high ozone stability and solubility. OTC had a high removal rate and degradation rate in acetic acid solution. With the increase of OTC dosage, the removal rate of OTC decreased in acetic acid. Removal rate of OTC was increased distinctly when ozone flow increased properly. It was also observed that free radical scavenger had a significantly negative effect on OTC ozonation degradation in acetic acid. Furthermore the main reactions of OTC ozone oxidation were direct oxidation and indirect oxidation in acetic acid. When Fe3+ and Co2+ were existent in acetic acid, the degradation of OTC was inhibited significantly. PMID:23379161

Li, Shi-Yin; Li, Xiao-Rong; Zhu, Yi-Ping; Zhu, Jiang-Peng; Wang, Guo-Xiang

2012-12-01

56

Putative ABC Transporter Responsible for Acetic Acid Resistance in Acetobacter aceti  

PubMed Central

Two-dimensional gel electrophoretic analysis of the membrane fraction of Acetobacter aceti revealed the presence of several proteins that were produced in response to acetic acid. A 60-kDa protein, named AatA, which was mostly induced by acetic acid, was prepared; aatA was cloned on the basis of its NH2-terminal amino acid sequence. AatA, consisting of 591 amino acids and containing ATP-binding cassette (ABC) sequences and ABC signature sequences, belonged to the ABC transporter superfamily. The aatA mutation with an insertion of the neomycin resistance gene within the aatA coding region showed reduced resistance to acetic acid, formic acid, propionic acid, and lactic acid, whereas the aatA mutation exerted no effects on resistance to various drugs, growth at low pH (adjusted with HCl), assimilation of acetic acid, or resistance to citric acid. Introduction of plasmid pABC101 containing aatA under the control of the Escherichia coli lac promoter into the aatA mutant restored the defect in acetic acid resistance. In addition, pABC101 conferred acetic acid resistance on E. coli. These findings showed that AatA was a putative ABC transporter conferring acetic acid resistance on the host cell. Southern blot analysis and subsequent nucleotide sequencing predicted the presence of aatA orthologues in a variety of acetic acid bacteria belonging to the genera Acetobacter and Gluconacetobacter. The fermentation with A. aceti containing aatA on a multicopy plasmid resulted in an increase in the final yield of acetic acid.

Nakano, Shigeru; Fukaya, Masahiro; Horinouchi, Sueharu

2006-01-01

57

Ethane to acetic acid oxidation over supported heteropoly acids  

Microsoft Academic Search

Molybdo(vanado)phosphoric heteropoly acids of Keggin structure supported on oxide supports (SiO2, TiO2, Al2O3) were used as catalysts for ethane to acetic acid oxidation in the range of reaction temperature from 250 to 400°C. Vanadium atoms introduced into Keggin structure enhanced oxidative activity of catalytic system, while vanadyl groups exchanged into cationic position diminished ethane conversion. Nature of support (acidic or

M. Sopa; A. W?c?aw-Held; M. Grossy; J. Pijanka; K. Nowi?ska

2005-01-01

58

Submillimeter wave spectrum of acetic acid  

NASA Astrophysics Data System (ADS)

We present a new global study of the submillimeter wave spectrum of the lowest three torsional states of acetic acid (CH3COOH). New measurements involving torsion-rotation transitions with J up to 79 and Ka up to 44 have been carried out between 230 and 845 GHz using the submillimeter wave spectrometers in University of Cologne and Jet Propulsion Laboratory. The new data were combined with previously published measurements and fitted using the rho-axis-method torsion-rotation Hamiltonian. The final fit used 93 parameters to give an overall weighted root-mean-square deviation of 0.85 for a dataset consisting of 7543, 6087, and 5171 transitions belonging, respectively, to the ground, first, and second excited torsional states and 1888 ?vt ? 0 transitions. This investigation presents more than a twofold expansion both in the J quantum number and frequency range coverage of the acetic acid spectrum. Numerous inter-torsional interactions have been observed. Furthermore, this is the highest J value ever treated with the rho-axis-method and provides a good test case for the theoretical model in use.

Ilyushin, Vadim V.; Endres, Christian P.; Lewen, Frank; Schlemmer, Stephan; Drouin, Brian J.

2013-08-01

59

Vinyl acetate formation in the reaction of acetylene with acetic acid catalyzed by zinc acetate supported on porous carbon spheres  

NASA Astrophysics Data System (ADS)

A kind of porous carbon spheres (PCS) was prepared by the carbonization of poly(vinylidene chloride) synthesized by suspension polymerization. Structure analyses revealed the existence of bumps and holes on the surface of PCS. The PCS, with the pore size between 0.8-1.2 nm, could be used as the support of zinc acetate because of the regular shape, high specific surface area, and good mechanical strength. Vinyl acetate was produced from acetylene and acetic acid using the PCS-supported zinc acetate (PCS-Zn) under mild conditions. In a single-pass operation performed at 220°C, the conversions of acetic acid and acetylene reached 22.6 and 5.3% respectively while the activity of vinyl acetate formation was above 1000 g mol-1 h-1.

Yan, Feng-Wen; Guo, Cun-Yue; Yan, Fang; Li, Feng-Bo; Qian, Qing-Li; Yuan, Guo-Qing

2010-05-01

60

Conformational studies of hydantoin-5-acetic acid and orotic acid.  

PubMed

Hydantoin-5-acetic acid [2-(2,5-dioxoimidazolidin-4-yl)acetic acid] and orotic acid (2,6-dioxo-1,2,3,6-tetrahydropyrimidine-4-carboxylic acid) each contain one rigid acceptor-donor-acceptor hydrogen-bonding site and a flexible side chain, which can adopt different conformations. Since both compounds may be used as coformers for supramolecular complexes, they have been crystallized in order to examine their conformational preferences, giving solvent-free hydantoin-5-acetic acid, C(5)H(6)N(2)O(4), (I), and three crystals containing orotic acid, namely, orotic acid dimethyl sulfoxide monosolvate, C(5)H(4)N(2)O(4)·C(2)H(6)OS, (IIa), dimethylammonium orotate-orotic acid (1/1), C(2)H(8)N(+)·C(5)H(3)N(2)O(4)(-)·C(5)H(4)N(2)O(4), (IIb), and dimethylammonium orotate-orotic acid (3/1), 3C(2)H(8)N(+)·3C(5)H(3)N(2)O(4)(-)·C(5)H(4)N(2)O(4), (IIc). The crystal structure of (I) shows a three-dimensional network, with the acid function located perpendicular to the ring. Interestingly, the hydroxy O atom acts as an acceptor, even though the carbonyl O atom is not involved in any hydrogen bonds. However, in (IIa), (IIb) and (IIc), the acid functions are only slightly twisted out of the ring planes. All H atoms of the acidic functions are directed away from the rings and, with respect to the carbonyl O atoms, they show an antiperiplanar conformation in (I) and synperiplanar conformations in (IIa), (IIb) and (IIc). Furthermore, in (IIa), (IIb) and (IIc), different conformations of the acid O=C-C-N torsion angle are observed, leading to different hydrogen-bonding arrangements depending on their conformation and composition. PMID:22307261

Gerhardt, Valeska; Tutughamiarso, Maya; Bolte, Michael

2012-01-18

61

Determination of odour detection thresholds for acetic acid and ethyl acetate in ice wine  

Microsoft Academic Search

Collectively acetic acid and ethyl acetate are responsible for ‘volatile acidity’ (VA) in wine. The detection limit or threshold for these compounds is well documented in table wine but not for ice wine. Knowledge of the ice wine thresholds is important for understanding perception limits and setting legal standards, particularly for a product with high intrinsic concentrations. Thresholds were determined

Margaret A. Cliff; Gary J. Pickering

2006-01-01

62

Biosynthesis of myristic acid in luminescent bacteria. [Vibrio harveyi  

Microsoft Academic Search

In vivo pulse-label studies have demonstrated that luminescent bacteria can provide myritic acid (14:0) required for the synthesis of the luciferase substrate myristyl aldehyde. Luminescent wild type Vibrio harveyi incubated with (¹⁴C) acetate in a nutrient-depleted medium accumulated substantial tree (¹⁴C)fatty acid (up to 20% of the total lipid label). Radio-gas chromatography revealed that > 75% of the labeled fatty

1987-01-01

63

Genetic organization of Acetobacter for acetic acid fermentation  

Microsoft Academic Search

Plasmid vectors for the acetic acid-producing strains ofAcetobacter andGluconobacter were constructed from their cryptic plasmids and the efficient transformation conditions were established. The systems allowed to reveal the genetic background of the strains used in the acetic acid fermentation. Genes encoding indispensable components in the acetic acid fermentation, such as alcohol dehydrogenase, aldehyde dehydrogenase and terminal oxidase, were cloned and

Teruhiko Beppu

1993-01-01

64

Oxidation of 3- and 4-carenes with mercuric acetate in acetic acid  

Microsoft Academic Search

1.A study was made of the oxidation of 3-carene with Hg(OAc)2 in acetic acid at 23 and 86°, and with (HgOAc)2 at 90°. The action of both of the oxidizing agents leads to the same acetylative oxidation products: the acetates of p-mentha-1,5-dien-8-ol and p-mentha-1(7),5-dien-8-ol.2.The products of the oxidation of 4-carene with Hg(OAc)2 in acetic acid at 20° contain the acetates

B. A. Arbuzov; V. V. Ratner; Z. G. Isaeva; É. Kh. Kazakova; M. G. Belyaeva

1971-01-01

65

Indole3-acetic acid in microbial and microorganism-plant signaling  

Microsoft Academic Search

Diverse bacterial species possess the ability to produce the auxin phytohormone indole-3-acetic acid (IAA). Different biosynthesis pathways have been identified and redundancy for IAA biosynthesis is widespread among plant-associated bacteria. Interactions between IAA-producing bacteria and plants lead to diverse outcomes on the plant side, varying from pathogenesis to phytostimulation. Reviewing the role of bacterial IAA in different microorganism-plant interactions highlights

Stijn Spaepen; Jos Vanderleyden; Roseline Remans

2007-01-01

66

The impact of acetate metabolism on yeast fermentative performance and wine quality: reduction of volatile acidity of grape musts and wines  

Microsoft Academic Search

Acetic acid is the main component of the volatile acidity of grape musts and wines. It can be formed as a by-product of alcoholic\\u000a fermentation or as a product of the metabolism of acetic and lactic acid bacteria, which can metabolize residual sugars to\\u000a increase volatile acidity. Acetic acid has a negative impact on yeast fermentative performance and affects the

Alice Vilela-Moura; Dorit Schuller; Arlete Mendes-Faia; Rui D. Silva; Susana R. Chaves; Maria João Sousa; Manuela Côrte-Real

2011-01-01

67

Oxidation of Indole-3-Acetic Acid to Oxindole-3-Acetic Acid by an Enzyme Preparation from Zea mays1  

PubMed Central

Indole-3-acetic acid is oxidized to oxindole-3-acetic acid by Zea mays tissue extracts. Shoot, root, and endosperm tissues have enzyme activities of 1 to 10 picomoles per hour per milligram protein. The enzyme is heat labile, is soluble, and requires oxygen for activity. Cofactors of mixed function oxygenase, peroxidase, and intermolecular dioxygenase are not stimulatory to enzymic activity. A heat-stable, detergent-extractable component from corn enhances enzyme activity 6- to 10-fold. This is the first demonstration of the in vitro enzymic oxidation of indole-3-acetic acid to oxindole-3-acetic acid in higher plants.

Reinecke, Dennis M.; Bandurski, Robert S.

1988-01-01

68

Genetics of Lactic Acid Bacteria  

NASA Astrophysics Data System (ADS)

Many meat (or fish) products, obtained by the fermentation of meat originating from various animals by the flora that naturally contaminates it, are part of the human diet since millenaries. Historically, the use of bacteria as starters for the fermentation of meat, to produce dry sausages, was thus performed empirically through the endogenous micro-biota, then, by a volunteer addition of starters, often performed by back-slopping, without knowing precisely the microbial species involved. It is only since about 50 years that well defined bacterial cultures have been used as starters for the fermentation of dry sausages. Nowadays, the indigenous micro-biota of fermented meat products is well identified, and the literature is rich of reports on the identification of lactic acid bacteria (LAB) present in many traditional fermented products from various geographical origin, obtained without the addition of commercial starters (See Talon, Leroy, & Lebert, 2007, and references therein).

Zagorec, Monique; Anba-Mondoloni, Jamila; Coq, Anne-Marie Crutz-Le; Champomier-Vergès, Marie-Christine

69

Granulibacter bethesdensis gen. nov., sp. nov., a distinctive pathogenic acetic acid bacterium in the family Acetobacteraceae.  

PubMed

A Gram-negative, aerobic, coccobacillus to rod-shaped bacterium was isolated from three patients with chronic granulomatous disease. The organism was subjected to a polyphasic taxonomic study. A multilocus phylogenetic analysis based on the 16S rRNA gene, the internal transcribed spacer (ITS) region and the RecA protein demonstrated that the organism belongs to a new sublineage within the acetic acid bacteria in the family Acetobacteraceae. Phenotypic features are summarized as follows: the organism grew at an optimum temperature of 35-37 degrees C and optimum pH of 5.0-6.5. It produced a yellow pigment, oxidized lactate and acetate, the latter weakly, produced little acetic acid from ethanol and could use methanol as a sole carbon source. The two major fatty acids were a straight-chain unsaturated acid (C18:1omega7c) and C16:0. The DNA base composition was 59.1 mol% G+C. The very weak production of acetic acid from ethanol, the ability to use methanol, the yellow pigmentation and high optimum temperature for growth distinguished this organism from other acetic acid bacteria. The unique phylogenetic and phenotypic characteristics suggest that the bacterium should be classified within a separate genus, for which the name Granulibacter bethesdensis gen. nov., sp. nov. is proposed. The type strain is CGDNIH1T (=ATCC BAA-1260T=DSM 17861T). PMID:17082400

Greenberg, David E; Porcella, Stephen F; Stock, Frida; Wong, Alexandra; Conville, Patricia S; Murray, Patrick R; Holland, Steven M; Zelazny, Adrian M

2006-11-01

70

Comparative study of recovering acetic acid with energy integrated schemes  

Microsoft Academic Search

The heat pumping and multi-effect distillation techniques were evaluated for recovering acetic acid from aqueous solutions with low boiling solvents, methyl tert-butyl ether (MTBE) and ethyl acetate (EtOAc). The overhead vapour recompression and two types of column cascading techniques are compared to the conventional acetic acid recovery scheme. It was found that (1) by switching the solvent to MTBE, approximately

S. Kürüm; Z. Fonyo

1996-01-01

71

Acetic acid pulping of wheat straw under atmospheric pressure  

Microsoft Academic Search

Atmospheric acetic acid pulping of wheat straw was carried out. Pulping conditions and their effects on pulp properties were investigated in detail, and a comparison between acetic acid (AcOH) pulp and soda-anthraquinone (AQ) pulps of wheat straw was made of the chemical com- position, strength, and fiber morphology of the pulps. Wheat straw was successfully pulped and fractionated into pulp

Xue-Jun PanYoshihiro Sano

1999-01-01

72

Asaia bogorensis gen. nov., sp. nov., an unusual acetic acid bacterium in the alpha-Proteobacteria.  

PubMed

Eight Gram-negative, aerobic, rod-shaped and peritrichously flagellated strains were isolated from flowers of the orchid tree (Bauhinia purpurea) and of plumbago (Plumbago auriculata), and from fermented glutinous rice, all collected in Indonesia. The enrichment culture approach for acetic acid bacteria was employed, involving use of sorbitol medium at pH 3.5. All isolates grew well at pH 3.0 and 30 degrees C. They did not oxidize ethanol to acetic acid except for one strain that oxidized ethanol weakly, and 0.35% acetic acid inhibited their growth completely. However, they oxidized acetate and lactate to carbon dioxide and water. The isolates grew well on mannitol agar and on glutamate agar, and assimilated ammonium sulfate for growth on vitamin-free glucose medium. The isolates produced acid from D-glucose, D-fructose, L-sorbose, dulcitol and glycerol. The quinone system was Q-10. DNA base composition ranged from 59.3 to 61.0 mol% G + C. Studies of DNA relatedness showed that the isolates constitute a single species. Phylogenetic analysis based on their 16S rRNA gene sequences indicated that the isolates are located in the acetic acid bacteria lineage, but distant from the genera Acetobacter, Gluconobacter, Acidomonas and Gluconacetobacter. On the basis of the above characteristics, the name Asaia bogorensis gen. nov., sp. nov. is proposed for these isolates. The type strain is isolate 71T (= NRIC 0311T = JCM 10569T). PMID:10758893

Yamada, Y; Katsura, K; Kawasaki, H; Widyastuti, Y; Saono, S; Seki, T; Uchimura, T; Komagata, K

2000-03-01

73

Effect of phenolic acids on glucose and organic acid metabolism by lactic acid bacteria from wine.  

PubMed

The influence of phenolic (p-coumaric, caffeic, ferulic, gallic and protocatechuic) acids on glucose and organic acid metabolism by two strains of wine lactic acid bacteria (Oenococcus oeni VF and Lactobacillus hilgardii 5) was investigated. Cultures were grown in modified MRS medium supplemented with different phenolic acids. Cellular growth was monitored and metabolite concentrations were determined by HPLC-RI. Despite the strong inhibitory effect of most tested phenolic acids on the growth of O. oeni VF, the malolactic activity of this strain was not considerably affected by these compounds. While less affected in its growth, the capacity of L. hilgardii 5 to degrade malic acid was clearly diminished. Except for gallic acid, the addition of phenolic acids delayed the metabolism of glucose and citric acid in both strains tested. It was also found that the presence of hydroxycinnamic acids (p-coumaric, caffeic and ferulic) increased the yield of lactic and acetic acid production from glucose by O. oeni VF and not by L. hilgardii 5. The results show that important oenological characteristics of wine lactic acid bacteria, such as the malolactic activity and the production of volatile organic acids, may be differently affected by the presence of phenolic acids, depending on the bacterial species or strain. PMID:19376463

Campos, Francisco M; Figueiredo, Ana R; Hogg, Tim A; Couto, José A

2009-02-07

74

Preservation of acidified cucumbers with a natural preservative combination of fumaric acid and allyl isothiocyanate that target lactic acid bacteria and yeasts  

Technology Transfer Automated Retrieval System (TEKTRAN)

Without the addition of preservative compounds cucumbers acidified with 150 mM acetic acid with pH adjusted to 3.5 typically undergo fermentation by lactic acid bacteria. Fumaric acid (20 mM) inhibited growth of Lactobacillus plantarum and the lactic acid bacteria present on fresh cucumbers, but sp...

75

21 CFR 862.1390 - 5-Hydroxyindole acetic acid/serotonin test system.  

Code of Federal Regulations, 2010 CFR

... 5-Hydroxyindole acetic acid/serotonin test system. 862.1390 Section... 5-Hydroxyindole acetic acid/serotonin test system. (a) Identification...A 5-hydroxyindole acetic acid/serotonin test system is a device...

2009-04-01

76

21 CFR 862.1390 - 5-Hydroxyindole acetic acid/serotonin test system.  

Code of Federal Regulations, 2010 CFR

... 5-Hydroxyindole acetic acid/serotonin test system. 862.1390 Section... 5-Hydroxyindole acetic acid/serotonin test system. (a) Identification...A 5-hydroxyindole acetic acid/serotonin test system is a device...

2010-04-01

77

The antibacterial activity and stability of acetic acid.  

PubMed

Acetic acid has been shown to have good antibacterial activity against micro-organisms such as Pseudomonas aeruginosa. This study examined the activity against a range of bacterial pathogens and also assessed any reduction in antibacterial activity due to evaporation or inactivation by organic material in dressings. Acetic acid was active at dilutions as low as 0.166% and the activity was not reduced by evaporation nor by inactivation by cotton swabs. Burn injuries are a major problem in countries with limited resources. Acetic acid is an ideal candidate for use in patients who are treated in those parts of the world. PMID:23747099

Fraise, A P; Wilkinson, M A C; Bradley, C R; Oppenheim, B; Moiemen, N

2013-06-07

78

Comparative genomics of the lactic acid bacteria  

Technology Transfer Automated Retrieval System (TEKTRAN)

Lactic acid-producing bacteria are associated with various plant and animal niches and play a key role in the production of fermented foods and beverages. We report nine genome sequences representing the phylogenetic and functional diversity of these bacteria. The small genomes of lactic acid bacter...

79

Inhibition of citrus fungal pathogens by using lactic acid bacteria.  

PubMed

The effect of lactic acid bacteria (LAB) on pathogenic fungi was evaluated and the metabolites involved in the antifungal effect were characterized. Penicillium digitatum (INTA 1 to INTA 7) and Geotrichum citri-aurantii (INTA 8) isolated from decayed lemon from commercial packinghouses were treated with imazalil and guazatine to obtain strains resistant to these fungicides. The most resistant strains (4 fungal strains) were selected for evaluating the antifungal activity of 33 LAB strains, among which only 8 strains gave positive results. The antifungal activity of these LAB strains was related to the production of lactic acid, acetic acid, and phenyllactic acid (PLA). A central composite design and the response surface methodology were used to evaluate the inhibitory effect of the organic acids produced by the LAB cultures. The antifungal activity of lactic acid was directly related to its concentration; however, acetic acid and PLA showed a peak of activity at 52.5 and 0.8 mM, respectively, with inhibition rates similar to those obtained with Serenade((R)) (3.0 ppm) imazalil (50 ppm) and guazatine (50 ppm). Beyond the peak of activity, a reduction in effectiveness of both acetic acid and PLA was observed. Comparing the inhibition rate of the organic acids, PLA was about 66- and 600-fold more effective than acetic acid and lactic acid, respectively. This study presents evidences on the antifungal effect of selected LAB strains and their end products. Studies are currently being undertaken to evaluate the effectiveness in preventing postharvest diseases on citrus fruits. PMID:20722936

Gerez, C L; Carbajo, M S; Rollán, G; Torres Leal, G; Font de Valdez, G

2010-08-01

80

Hydrothermal production of formic and acetic acids from syringol  

Microsoft Academic Search

The production of formic and acetic acids (or salts) by hydrothermal oxidation of syringol, a model compound for lignin, was\\u000a investigated using a batch reactor. Results show that the highest yields of formic and acetic acids were, respectively, 59.6%\\u000a and 11.3% at the reaction condition of 0.5 mol\\/L NaOH, 120% H2O2 supply and 280 °C. These results will inform studies

Lu-ting Pan; Zheng Shen; Lei Wu; Ya-lei Zhang; Xue-fei Zhou; Fang-ming Jin

2010-01-01

81

Acetic acid pulping of wheat straw under atmospheric pressure  

Microsoft Academic Search

Atmospheric acetic acid pulping of wheat straw was carried out. Pulping conditions and their effects on pulp properties were\\u000a investigated in detail, and a comparison between acetic acid (AcOH) pulp and soda-anthraquinone (AQ) pulps of wheat straw\\u000a was made of the chemical composition, strength, and fiber morphology of the pulps. Wheat straw was successfully pulped and\\u000a fractionated into pulp (cellulose),

Xue-Jun Pan; Yoshihiro Sano

1999-01-01

82

Activated carbon sheet prepared from softwood acetic acid lignin  

Microsoft Academic Search

As an example of activated carbon (AC) moldings, AC sheets were prepared from thermoplastic acetic acid lignin by lamination.\\u000a The resulting AC sheets are a new type of product that can be applied as water and air cleaners. Powdered softwood acetic\\u000a acid lignin (SAL) was molded into sheets by a thermal pressing method. When the sheet was carbonized under a

Yasumitsu Uraki; Ryo Taniwatashi; Satoshi Kubo; Yoshihiro Sano

2000-01-01

83

Infrared Studies of Water Adsorption on Acetic Acid thin films  

NASA Astrophysics Data System (ADS)

Infrared reflection-absorption spectroscopy is used to investigate H2O ice deposited onto non-crystalline (dimers [1]) and polycrystalline (infinite chains [1]) acetic acid films. The condensed water film grown at ˜135 K on these different substrates can be characterized as amorphous dense ice. The H2O molecules are shown to interact mainly with the carbonyl and the carboxyl oxygens, forming hydrogen bonds. Upon water adsorption on the non-crystalline acetic acid film, saturation of the change induced in the intensity of the C=O and C-O peaks occurs at an average H2O exposure of ˜ 2.52 L. The amount of H-bonding involving C=O or C-O (of acetic acid) and OH (of water) on the polycrystalline film has been reduced considerably compared to the situation on the non-annealed one, but saturation of the carbonyl oxygen even for a water exposure of 9 L has not been observed while the carboxyl oxygen saturates at ˜2.76 L. Thermal evolution studies for the ice film on non-crystalline and polycrystalline acetic acid films show that water co-evaporates with acetic acid likely as a water-acetic acid complex in the temperature range of 140-155 K, which continues until the entire ice film has been exhausted at 160 K. [1]: Q. Gao and K. T. Leung, J. Phys. Chem. B 109, (2005) 13263. .

Malick Thiam, Michel; Ebrahimi, Maryam; Tong Leung, Kam

2006-03-01

84

Fractionation of wheat straw by atmospheric acetic acid process.  

PubMed

Fractionation of wheat straw was investigated using an atmospheric acetic acid process. Under the typical conditions of 90% (v/v) aqueous AcOH, 4% H(2)SO(4) (w/w, on straw), ratio of liquor to straw (L/S) 10 (v/w), pulping temperature 105 degrees C, and pulping time 3h, wheat straw was fractionated to pulp (cellulose), lignin and monosaccharides mainly from hemicellulose with yields of approximately 50%, 15% and 35%, respectively. Acetic acid pulp from the straw had an acceptable strength for paper and could be bleached to a high brightness over 85% with a short bleaching sequence. Acetic acid pulp was also a potential feedstock for fuels and chemicals. The acetic acid process separated pentose and hexose in wheat straw to a large extent. Most of the pentose (xylan) was dissolved, whereas the hexose (glucan) remained in the pulp. Approximately 30% of carbohydrates in wheat straw were hydrolyzed to monosaccharides during acetic acid pulping, of which xylose accounted for 70% and glucose for 12%. The acetic acid lignin from wheat straw showed relatively lower molecular weight and fusibility, which made the lignin a promising raw material for many products, such as adhesive and molded products. PMID:15734313

Pan, Xuejun; Sano, Yoshihiro

2004-12-19

85

Fast Esterification of Acetic Acid with Short Chain Alcohols in Microchannel Reactor  

Microsoft Academic Search

Microchannel reactor was used for the fast synthesis of acetic acid esters, including methyl acetate, ethyl acetate, n-propyl acetate and n-butyl acetate. Effects of the inner diameter of microchannel reactors, dosage of catalyst, residence time, reaction temperature\\u000a and molar ratio of alcohol to acetic acid on yields of esters were studied in the p-toluene sulfonic acid-catalyzed homogeneous esterification of acetic

Xingjun Yao; Jianfeng Yao; Lixiong Zhang; Nanping Xu

2009-01-01

86

Formation of Amino Acids from Reactor Irradiated Ammonium Acetate  

NASA Astrophysics Data System (ADS)

Ammonium acetate in various conditions was irradiated in a reactor to examine the contributions of both the reactor radiations and recoiled14C nucleis to form the biologically interesting molecules. Present investigations demonstrated that several amino acids, glycine, alanine, ?-alanine and GABA, and may-be aspartic acid, serine and valine by prolonged irradiation, were formed in the aqueous solutions of ammonium acetate.14C-radioactivities were also found distributed in these amino acids. However, no special relationship between14C-radioactivity and these amino acids formed was observed.

Akaboshi, M.; Kawai, K.; Maki, H.; Kawamoto, K.; Honda, Y.

1982-12-01

87

Indole3-acetic acid production from indole-3-acetonitrile in Bradyrhizobium  

Microsoft Academic Search

Bradyrhizobium japonicum USDA 110, Bradyrhizobium elkanii USDA 76 and two Bradyrhizobium sp. strains, BTA-1 and BGA-1, produced indole-3-acetamide (IAM). IAM is a characteristic intermediate in indole-3-acetic acid production from tryptophan by the tryptophan-2-monooxygenase (TMO) pathway, by other bacteria, such as Agrobacterium tumefaciens and Pseudomonas savastanoi. However, none of these strains showed any TMO activity. Moreover, the TMO gene could not

Mariá C. Vega-Hernández; Milagros León-Barrios; Ricardo Pérez-Galdona

2002-01-01

88

Effect of ethyl acetate on carbohydrate components and crystalline structure of pulp produced in aqueous acetic acid pulping  

Microsoft Academic Search

The aim of this study was to investigate the changes in carbohydrate components and the crystalline structure in hemp bast\\u000a fibers by adding ethyl acetate to acetic acid\\/water pulping processes. It was found that ethyl acetate added to acetic acid\\/water\\u000a process had a positive effect on yield, viscosity and carbohydrate components in pulp. It was assumed that the delignification\\u000a ratio

Esat Gümü?kaya; Mustafa Usta; Mualla Balaban Uçar

2009-01-01

89

Acetals of lactams and acid amides  

Microsoft Academic Search

A new approach to the synthesis of one-, two-, and three-ring compounds from enamides and enamino ketones was investigated. Thus the reaction of a-cyano-ß-dimethylaminoacrylamide with guanidine gave 2, 4-diamino-5-carbamidopyrimidine, the cyclization of which with dimethylformamide acetal and subsequent hydrolysis gave 2-amino-5,6-dihydro-5-oxopyrimido[4,5-d]pyrimidine. An enamino ketone — 1-benzoyl-2-dimethylamino-2-methylethylene — was subjected to condensation with guanidine, thiourea, and acetamidine, as a result of

O. Ya. Belyaeva; V. G. Granik; R. G. Glushkov; T. F. Vlasova; O. S. Anisimova

1978-01-01

90

Production of indole-3-acetic acid, aromatic amino acid aminotransferase activities and plant growth promotion by Pantoea agglomerans rhizosphere isolates  

Microsoft Academic Search

The production of auxins, such as indole-3-acetic acid (IAA), by rhizobacteria has been associated with plant growth promotion,\\u000a especially root initiation and elongation. Six indole-producing bacteria isolated from the rhizosphere of legumes grown in\\u000a Saskatchewan soils and identified as Pantoea agglomerans spp. were examined for their ability to promote the growth of canola, lentil and pea under gnotobiotic conditions and

Elena Sergeeva; Danielle L. M. Hirkala; Louise M. Nelson

2007-01-01

91

Safety of industrial lactic acid bacteria  

Microsoft Academic Search

Lactic acid bacteria (LAB) are ubiquitous in fermented and non-fermented foods and are common components of the human commensal microflora. This long history of human exposure and consumption has led to the reasonable conclusion that they are generally safe. Recent attention has also focused on their possible role as probiotic bacteria, promoting beneficial health effects. There have, however, been a

Martin R. Adams; Surrey GU

1999-01-01

92

Evolutionary Genomics of Lactic Acid Bacteria  

Microsoft Academic Search

The lactic acid bacteria (LAB) might be the most numerous group of bacteria linked to humans. They are naturally asso- ciated with mucosal surfaces, particularly the gastrointestinal tract, and are also indigenous to food-related habitats, includ- ing plant (fruits, vegetables, and cereal grains), wine, milk, and meat environments (60, 61). The LAB include both important pathogens, e.g., several Streptococcus species,

Kira S. Makarova; Eugene V. Koonin

2007-01-01

93

Simultaneous acetic acid separation and monosaccharide concentration by reverse osmosis.  

PubMed

This study aimed to investigate the feasibility and efficiency of simultaneous acetic acid separation and sugar concentration in model lignocellulosic hydrolyzates by reverse osmosis. The effects of operation parameters such as pH, temperature, pressure and feed concentration on the solute retentions were examined with a synthetic xylose–glucose–acetic acid model solution. Results showed that the monosaccharides were almost completely rejected at above 20 bar, while the acetic acid retention increased with the increase in pH and pressure, and decreased with the temperature increase. The maximum separation factors of acetic acid over xylose and glucose reached as high as 211.5 and 228.4 at pH 2.93 (the initial pH of model lignocellulosic hydrolyzates), 40 °C and 20 bar. Furthermore, the concentration and diafiltration process were employed at optimal operation conditions. Consequently, a high sugar concentration and a beneficially lower acetic acid concentration were simultaneously achieved by reverse osmosis. PMID:23376199

Zhou, Fanglei; Wang, Cunwen; Wei, Jiang

2013-01-03

94

Photodissociation spectroscopy of the Mg{sup +}-acetic acid complex  

SciTech Connect

We have studied the structure and photodissociation of Mg{sup +}-acetic acid clusters. Ab initio calculations suggest four relatively strongly bound ground state isomers for the [MgC{sub 2}H{sub 4}O{sub 2}]{sup +} complex. These isomers include the cis and trans forms of the Mg{sup +}-acetic acid association complex with Mg{sup +} bonded to the carbonyl O atom of acetic acid, the Mg{sup +}-acetic acid association complex with Mg{sup +} bonded to the hydroxyl O atom of acetic acid, or to a Mg{sup +}-ethenediol association complex. Photodissociation through the Mg{sup +}-based 3p<-3s absorption bands in the near UV leads to direct (nonreactive) and reactive dissociation products: Mg{sup +}, MgOH{sup +}, Mg(H{sub 2}O){sup +}, CH{sub 3}CO{sup +}, and MgCH{sub 3}{sup +}. At low energies the dominant reactive quenching pathway is through dehydration to Mg(H{sub 2}O){sup +}, but additional reaction channels involving C-H and C-C bond activation are also open at higher energies.

Abate, Yohannes; Kleiber, P. D. [Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242 and Optical Science and Technology Center, University of Iowa, Iowa City, Iowa 52242 (United States)

2006-11-14

95

THE ANTIMICROBIAL ACTIVITY OF GREEN TEA (Camellia sinensis) ON Staphylococcus aureus IN COMBINATION WITH ASCORBIC ACID, ACETIC ACID, AND SODIUM CHLORIDE  

Microsoft Academic Search

Green tea contains polyphenolic catechins that have been demonstrated to effectively inhibit Staphylococcus aureus and related bacteria. This study aimed to determine if home-brewed green tea could inhibit S. aureus through paper disk diffusion and minimum inhibitory concentration experiments. It was hypothesized that green tea brewed for varying periods of time in solutions with ascorbic acid, acetic acid, and sodium

Timothy Barnum; Steven Castellano; Annie Chen; Neha Jariwala; Andrew Jung; Christina Sedberry; Heather Tynan; Charles Zou; Rachel Sandler; Danielle Cusmano

96

Catalysis of the Carbonylation of Alcohols to Carboxylic Acids Including Acetic Acid Synthesis from Methanol.  

ERIC Educational Resources Information Center

Monsanto's highly successful synthesis of acetic acid from methanol and carbon monoxide illustrates use of new starting materials to replace pretroleum-derived ethylene. Outlines the fundamental aspects of the acetic acid process and suggests ways of extending the synthesis to higher carboxylic acids. (JN)

Forster, Denis; DeKleva, Thomas W.

1986-01-01

97

Catalysis of the Carbonylation of Alcohols to Carboxylic Acids Including Acetic Acid Synthesis from Methanol.  

ERIC Educational Resources Information Center

|Monsanto's highly successful synthesis of acetic acid from methanol and carbon monoxide illustrates use of new starting materials to replace pretroleum-derived ethylene. Outlines the fundamental aspects of the acetic acid process and suggests ways of extending the synthesis to higher carboxylic acids. (JN)|

Forster, Denis; DeKleva, Thomas W.

1986-01-01

98

Photoionization of small sodium-doped acetic acid clusters  

NASA Astrophysics Data System (ADS)

The uptake of sodium and the fragmentation before and after ``soft'' photoionization with ultraviolet light are investigated for small acetic acid clusters. The acetic acid clusters are generated in a supersonic expansion and ionized with ultraviolet light after doping with sodium in a pick-up chamber. The composition of the bare acetic acid clusters in the molecular beam is determined independently from complementary photoionization experiments using extreme ultraviolet light. The experimental results are analyzed with the help of density functional calculations for energetics and statistical adiabatic channel calculations for fragmentation kinetics. The study demonstrates that the detected ions originate from fragmentation in the neutral as well as in the ionic state, and in particular that the fragmentation pathway strongly depends on the cluster size.

Forysinski, Piotr W.; Zielke, Philipp; Luckhaus, David; Corbett, Jennifer; Signorell, Ruth

2011-03-01

99

CARCINOGENICITY OF THE CHLORINATED ACETIC ACIDS  

EPA Science Inventory

Dichloroacetic Acid (DCAA) and trichloroacetic acid (TCAA) comprise a major fraction of the reaction products formed when water containing a variety of precursor humic materials is chlorinated. Both DCAA and TCAA administered in the drinking water increased the incidence of hepat...

100

Acidophilic, heterotrophic bacteria of acidic mine waters  

SciTech Connect

Obligately acidophilic, heterotrophic bacteria were isolated both from enrichment cultures developed with acidic mine water and from natural mine drainage. The bacteria were grouped by the ability to utilize a number of organic acids as sole carbon sources. None of the strains were capable of chemolithotrophic growth on inorganic reduced iron and sulfur compounds. All bacteria were rod shaped, gram negative, nonencapsulated, motile, capable of growth at pH 2.6 but not at pH 6.0, catalase and oxidase positive, strictly aerobic, and capable of growth on citric acid. The bacteria were cultivatable on solid nutrient media only if agarose was employed as the hardening agent. Bacterial densities in natural mine waters ranged from approximately 20 to 250 cells per ml, depending upon source and culture medium.

Wichlacz, P.L.; Unz, R.F.

1981-05-01

101

Comparative genomics of the lactic acid bacteria.  

PubMed

Lactic acid-producing bacteria are associated with various plant and animal niches and play a key role in the production of fermented foods and beverages. We report nine genome sequences representing the phylogenetic and functional diversity of these bacteria. The small genomes of lactic acid bacteria encode a broad repertoire of transporters for efficient carbon and nitrogen acquisition from the nutritionally rich environments they inhabit and reflect a limited range of biosynthetic capabilities that indicate both prototrophic and auxotrophic strains. Phylogenetic analyses, comparison of gene content across the group, and reconstruction of ancestral gene sets indicate a combination of extensive gene loss and key gene acquisitions via horizontal gene transfer during the coevolution of lactic acid bacteria with their habitats. PMID:17030793

Makarova, K; Slesarev, A; Wolf, Y; Sorokin, A; Mirkin, B; Koonin, E; Pavlov, A; Pavlova, N; Karamychev, V; Polouchine, N; Shakhova, V; Grigoriev, I; Lou, Y; Rohksar, D; Lucas, S; Huang, K; Goodstein, D M; Hawkins, T; Plengvidhya, V; Welker, D; Hughes, J; Goh, Y; Benson, A; Baldwin, K; Lee, J-H; Díaz-Muñiz, I; Dosti, B; Smeianov, V; Wechter, W; Barabote, R; Lorca, G; Altermann, E; Barrangou, R; Ganesan, B; Xie, Y; Rawsthorne, H; Tamir, D; Parker, C; Breidt, F; Broadbent, J; Hutkins, R; O'Sullivan, D; Steele, J; Unlu, G; Saier, M; Klaenhammer, T; Richardson, P; Kozyavkin, S; Weimer, B; Mills, D

2006-10-09

102

Comparative genomics of the lactic acid bacteria  

PubMed Central

Lactic acid-producing bacteria are associated with various plant and animal niches and play a key role in the production of fermented foods and beverages. We report nine genome sequences representing the phylogenetic and functional diversity of these bacteria. The small genomes of lactic acid bacteria encode a broad repertoire of transporters for efficient carbon and nitrogen acquisition from the nutritionally rich environments they inhabit and reflect a limited range of biosynthetic capabilities that indicate both prototrophic and auxotrophic strains. Phylogenetic analyses, comparison of gene content across the group, and reconstruction of ancestral gene sets indicate a combination of extensive gene loss and key gene acquisitions via horizontal gene transfer during the coevolution of lactic acid bacteria with their habitats.

Makarova, K.; Slesarev, A.; Wolf, Y.; Sorokin, A.; Mirkin, B.; Koonin, E.; Pavlov, A.; Pavlova, N.; Karamychev, V.; Polouchine, N.; Shakhova, V.; Grigoriev, I.; Lou, Y.; Rohksar, D.; Lucas, S.; Huang, K.; Goodstein, D. M.; Hawkins, T.; Plengvidhya, V.; Welker, D.; Hughes, J.; Goh, Y.; Benson, A.; Baldwin, K.; Lee, J.-H.; Diaz-Muniz, I.; Dosti, B.; Smeianov, V.; Wechter, W.; Barabote, R.; Lorca, G.; Altermann, E.; Barrangou, R.; Ganesan, B.; Xie, Y.; Rawsthorne, H.; Tamir, D.; Parker, C.; Breidt, F.; Broadbent, J.; Hutkins, R.; O'Sullivan, D.; Steele, J.; Unlu, G.; Saier, M.; Klaenhammer, T.; Richardson, P.; Kozyavkin, S.; Weimer, B.; Mills, D.

2006-01-01

103

T09PAA101 Acetic Acid Glacial  

Center for Food Safety and Applied Nutrition (CFSAN)

Text Version... 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP) (hereinafter referred to as “PAA solutions”) as an antimicrobial to treat poultry carcasses, to ... More results from www.fda.gov/downloads/food/ingredientspackaginglabeling

104

Determination of Formic and Acetic Acid in Chondritic Meteorites  

NASA Astrophysics Data System (ADS)

The concentrations of formic and acetic acid have been determined using ion exclusion chromatography after water extraction from several chondritic meteorite samples. Monocarboxylic acids are of great importance because of their high concentration in meteorites and for their role as precursor molecules in organic synthesis [1]. The concentration of acetic acid has been determined previously using gas chromatography [2,3]. Prior gas chromatographic analyses failed to resolve formic acid and so the results were limited to carboxylic acids having two or more carbons. Alternatively, wet chemical methods for the determination of formic acid, although precise, are lengthy and difficult to reproduce [4]. Ion exclusion chromatography (ICE) is an excellent technique for the simultaneous determination of formic and acetic acids. Using ICE the carboxylic acids can be determined in less time and with minimal sample handling. In most cases the amount of formic acid present is found to be lower than the amount of acetic acid present. This contradicts the accepted synthesis scheme of higher homologs being made from lower members, where the formic acid would be expected to have a higher concentration than acetic acid. Other monocarboxylic acids in the homologous series (C(sub)2-C(sub)7) have been shown to decrease with increasing carbon number as expected [2,3]. This data suggests that either the formic acid may have been preferentially depleted or it may have a different synthesis mechanism as compared with the other monocarboxylic acids present in meteorites. Additionally, there is a relationship between the amount of formic and acetic acid present and the oxidation state of the iron in the chondrites. As the matrix environment becomes more oxidizing, the amount of the two monocarboxylic acids increases comparatively. Furthermore, the ratio of formic to acetic acid starts to increase as the metal phase is more oxidized, suggesting that a more oxidized matrix environment in some way makes the production of higher homologs from lower members more favorable. References: [1] Cronin J. R. et al. (1988) In Meteorites and the Early Solar System (J. F. Kerridge and M. S. Matthews, eds.), 819-857. Univ. of Arizona. [2] Yuen G. U. and Kvenvolden K. A. (1974) Nature, 246, 301-303. [3] Yuen G. et al. (1984) Nature, 307, 252-254. [4] Kimball B. (1988) M.S. thesis, Arizona State Univ. [5] Urey H. C. and Craig H. (1953) GCA, 4, 36-82. [6] Sears D. W. and Dodd R. T. (1988) In Meteorites and the Early Solar System (J. F. Kerridge and M. S. Matthews, eds.), 3-31. Univ. of Arizona. Table 1, which appears here in the hard copy, shows a representative concentration of formic and acetic acid (in ppm) for select chondrites as measured by ion exclusion chromatography.

Briscoe, J. F.; Moore, C. B.

1993-07-01

105

Electrochemical behavior of graphite in electrolyte of sulfuric and acetic acid  

Microsoft Academic Search

Electrochemical formation of graphite intercalation compounds (GICs) has been studied in the electrolyte with mixed sulfuric acid and acetic acid. The results show that, with addition of acetic acid, GICs can be synthesized in the electrolyte with sulfuric acid concentration as low as 3.6M, even though no GIC is formed in pure acetic acid. The stage structure of the synthesized

F. Kang; T.-Y. Zhang; Y. Leng

1997-01-01

106

Aerobic oxidation of aqueous ethanol using heterogeneous gold catalysts: Efficient routes to acetic acid and ethyl acetate  

Microsoft Academic Search

The aerobic oxidation of aqueous ethanol to produce acetic acid and ethyl acetate was studied using heterogeneous gold catalysts. Comparing the performance of Au\\/MgAl2O4 and Au\\/TiO2 showed that these two catalysts exhibited similar performance in the reaction. By proper selection of the reaction conditions, yields of 90–95% of acetic acid could be achieved at moderate temperatures and pressures. Based on

Betina Jørgensen; Sofie Egholm Christiansen; Marie Louise Dahl Thomsen; Claus Hviid Christensen

2007-01-01

107

Condensation of acetol and acetic acid vapor with sprayed liquid  

Technology Transfer Automated Retrieval System (TEKTRAN)

A cellulose-derived fraction of biomass pyrolysis vapor was simulated by evaporating acetol and acetic acid (AA) from flasks on a hot plate. The liquid in the flasks was infused with heated nitrogen. The vapor/nitrogen stream was superheated in a tube oven and condensed by contact with a cloud of ...

108

Recovery of acetic acid from waste streams by extractive distillation  

Microsoft Academic Search

Wastes have been considered to be a serious worldwide environmental problem in recent years. Because of increasing pollution, these wastes should be treated. However, industrial wastes can contain a number of valuable organic components. Recovery of these components is important economically. Using conventional distillation techniques, the separation of acetic acid and water is both impractical and uneconomical, because it often

H. Demiral; M. Ercengiz Yildirim

109

Catalytic steam reforming of acetic acid for hydrogen production  

Microsoft Academic Search

A variety of supported metal catalysts were tested under conditions of steam reforming of acetic acid (HAc), which was selected as a model compound for pyrolysis oil. The influence of several parameters on catalytic activity and selectivity were examined, including catalyst composition, i.e. nature of the metal and the carrier, reaction temperature and time on stream. The metallic phase of

A. C. Basagiannis; X. E. Verykios

2007-01-01

110

Electrosynthesis of anisidines in aqueous sulfuric and acetic acids  

NASA Astrophysics Data System (ADS)

The influence of the concentrations of acetic and sulfuric acids on the efficiency of anisole amination by means of hydroxylamine and Ti(IV)/Ti(III) mediator was studied. Ortho- and para-anisidines were obtained with the total yields of about 79% by current and hydroxylamine.

Lisitsyn, Yu. A.; Grigor'eva, L. V.

2009-03-01

111

Intramolecular carbon isotope distribution of acetic acid in vinegar.  

PubMed

Compound-specific carbon isotope analysis of acetic acid is useful for origin discrimination and quality control of vinegar. Intramolecular carbon isotope distributions, which are each carbon isotope ratios of the methyl and carboxyl carbons in the acetic acid molecule, may be required to obtain more detailed information to discriminate such origin. In this study, improved gas chromatography-pyrolysis-gas chromatography-combustion-isotope ratio mass spectrometry (GC-Py-GC-C-IRMS) combined with headspace solid-phase microextraction (HS-SPME) was used to measure the intramolecular carbon isotope distributions of acetic acid in 14 Japanese vinegars. The results demonstrated that the methyl carbons of acetic acid molecules in vinegars produced from plants were mostly isotopically depleted in (13)C relative to the carboxyl carbon. Moreover, isotopic differences (?(13)C(carboxyl) - ?(13)C(methyl)) had a wide range from -0.3 to 18.2‰, and these values differed among botanical origins, C3, C4, and CAM plants. PMID:21830825

Hattori, Ryota; Yamada, Keita; Kikuchi, Makiko; Hirano, Satoshi; Yoshida, Naohiro

2011-08-18

112

Measurement of acetic acid using a fibre Bragg grating interferometer  

Microsoft Academic Search

An optical fibre sensor for determination of acetic acid is presented. The sensing probe is based on a fibre Bragg grating (FBG) Fabry-Perot cavity, coated with a thin film of sol-gel-PVP (polyvinylpyrrolidone) composite material. The polymeric thin film renders the interferometric output sensitive to the presence of carboxylic acid species. Results show that the wavelength of the interferometric peaks changes

C. Jesus; S. F. O. Silva; M. Castanheira; G. González Aguilar; O. Frazão; P. A. S. Jorge; J. M. Baptista

2009-01-01

113

Interferometric fibre-optic sensor for acetic acid measurement  

Microsoft Academic Search

An optical fibre sensor for determination of acetic acid is presented. The sensing probe is based on a fiber Bragg grating (FBG) Fabry-Perot cavity, coated with a thin film of sol-gel-PVP (polyVynil Pirrolidone) composite material. The polymeric thin film renders interferometric output sensitive to the presence of carboxylic acid species. Results show that the wavelength of the interferometric peaks change

C. Jesus; S. F. O. Silva; M. Castanheira; G. Gonzalez Aguilar; O. Frazao; P. A. S. Jorge; J. M. Baptista

2009-01-01

114

Liquid crystalline solutions of cellulose acetate in phosphoric acid  

Microsoft Academic Search

The influence has been studied of both the acid strength of phosphoric acid and the degree of substitution of cellulose acetate on the formation of an anisotropic phase. The solvent composition is expressed as a P2O5 concentration. It was found that the clearing temperature increases strongly with decreasing amount of water in the solvent.The influence of the degree of substitution

H Boerstoel; H Maatman; S. J Picken; R Remmers; J. B Westerink

2001-01-01

115

Engineering strategies aimed at control of acidification rate of lactic acid bacteria.  

PubMed

The ability of lactic acid bacteria to produce lactic acid from various sugars plays an important role in food fermentations. Lactic acid is derived from pyruvate, the end product of glycolysis and thus a fast lactic acid production rate requires a high glycolytic flux. In addition to lactic acid, alternative end products--ethanol, acetic acid and formic acid--are formed by many species. The central role of glycolysis in lactic acid bacteria has provoked numerous studies aiming at identifying potential bottleneck(s) since knowledge about flux control could be important not only for optimizing food fermentation processes, but also for novel applications of lactic acid bacteria, such as cell factories for the production of green fuels and chemicals. With respect to the control and regulation of the fermentation mode, some progress has been made, but the question of which component(s) control the main glycolytic flux remains unanswered. PMID:23266099

Martinussen, Jan; Solem, Christian; Holm, Anders Koefoed; Jensen, Peter Ruhdal

2012-12-19

116

Occurrence and metabolism of 7-hydroxy-2-indolinone-3-acetic acid in Zea mays.  

PubMed

7-Hydroxy-2-indolinone-3-acetic acid was identified as a catabolite of indole-3-acetic acid in germinating kernels of Zea mays and found to be present in amounts of ca 3.1 nmol/kernel. 7-Hydroxy-2-indolinone-3-acetic acid was shown to be a biosynthetic intermediate between 2-indolinone-3-acetic acid and 7-hydroxy-2-indolinone-3-acetic acid-7'-O-glucoside in both kernels and roots of Zea mays. Further metabolism of 7-hydroxy-2-[5-3H]-indolinone-3-acetic acid-7'-O-glucoside occurred to yield tritiated water plus, as yet, uncharacterized products. PMID:11539052

Lewer, P; Bandurski, R S

1987-01-01

117

Method for enzymatic determination of imidazole acetic acid.  

PubMed

A method for enzymatic assay of imidazole acetic acid (ImAA) was developed, based on the strict substrate specificity of imidazole acetate monooxygenase from Pseudomonas sp. [Maki et al. (1969) J. Biol. Chem., 244., 2942-2950], which catalyzes concomitant conversion of NADH to NAD+. Thus, ImAA was determined by measuring decrease in absorbancy at 340 nm. Tissue extracts were partially purified and/or concentrated by column chromatography on Bio-Rad AG-1 before enzymatic assay. The lowest measurable level of ImAA by this method was 2 nmol. PMID:6869819

Watanabe, T; Kambe, H; Imamura, I; Taguchi, Y; Tamura, T; Wada, H

1983-04-15

118

Effect of Chitosan Acetate on Bacteria Occurring on Neungee Mushrooms, Sarcodon aspratus  

PubMed Central

Minimal growth inhibitory concentrations (MICs) of chitosan acetate (M.W. 60 kDa) on heterotrophic bacteria (strains MK1, S, and R) isolated from the soft-rotten tissues of Neungee mushroom (Sarcodon aspratus) were measured. The slimy substance produced by the MK1 strain was responsible for the diseased mushroom's appearance. The S and R strains were members of the Burkholderia cepacia complex. These strains showed different levels of susceptibility toward chitosan acetate. The MIC of chitosan acetate against the MK1 and S strains was 0.06%. The MIC against the R strain was greater than 0.10%. Survival fractions of the MK1 and S strains at the MIC were 3 × 10-4 and 1.4 × 10-3 after 24 h, and 2 × 10-4 and 7 × 10-4 after 48 h, respectively. Survival fractions of the R strain after 24 and 48 hr at 0.1% chitosan acetate were 1 × 10-2 and 6.9 × 10-3, respectively. Compared to the MK1 and S strains, the low susceptibility of the R stain towards chitosan acetate could be due to the ability of the R strain to utilize chitosan as a carbon source. Thirty-eight percent of Neungee pieces treated in a 0.06% chitosan acetate solution for 2~3 second did not show any bacterial growth at 4 days, whereas bacterial growth around untreated mushroom pieces occurred within 2 days. These data suggest that chitosan acetate is highly effective in controlling growth of indigenous microorganisms on Neungee. The scanning electron micrographs of the MK1 strain treated with chitosan revealed a higher degree of disintegrated and distorted cellular structures.

Park, Bom Soo; Koo, Chang-Duck; Ka, Kang Hyeon

2008-01-01

119

High resolution acetic acid survey and water vapor radiometer  

NASA Astrophysics Data System (ADS)

Planets, comets, stars, galaxies and the interstellar medium (ISM) emit complex but distinct molecular spectra. These spectra reveal the chemical composition and physical conditions in the objects. For example, many biologically important molecules, such as acetic acid, formic acid, vinyl cyanide and ethyl cyanide, have been detected in hot molecular cores in the ISM. A diversity of molecules creates complicated and yet interesting astrochemistry in hot cores. However, the formation mechanisms of large molecules are still unclear. Hence large molecule observations are essential to understand hot core chemistry. Among these molecules, acetic acid is one of the most important large species in hot cores. It is a possible precursor of glycine, the simplest amino acid. It only has been detected in high-mass hot cores without oxygen/nitrogen chemical differentiation, which is key to hot core chemical models. Using the Combined Array for Research in Millimeter-wave Astronomy (CARMA), we have conducted an acetic acid survey in hot cores. In our survey, we have discovered a new acetic acid hot core, G19.61-0.23, which also shows no chemical differentiation. Therefore, we suggest that both large oxygen and nitrogen- bearing species play important roles in acetic acid formation. Ground-based interferometric observations are severely affected by atmospheric conditions. Phase correction is a technique to obtain high quality data and achieve great scientific goals. For our acetic acid survey, a better phase correction technique can not only detect weaker transitions of large molecules, but also increase the map resolution of hot cores. Water vapor radiometers (WVRs) are designed to improve the technique by observing tropospheric water vapor along the lines of sight of interferometers. We have numerically demonstrated the importance of phase correction for interferometric observations and examined the water vapor phase correction technique. Furthermore, we have built two WVR prototypes with new calibration, thermal regulation and backend systems. The WVR prototypes had been tested in a laboratory, on a roof and at the CARMA site to verify their performance. We conclude the WVR thermal stability and dynamic range are critical while the enormous and rapid fluctuations of the sky background emission overwhelm the WVR dynamic range and degrade the WVR sensitivity.

Shiao, Yu-Shao

2008-08-01

120

Effects of acetic acid on light scattering from cells  

PubMed Central

Abstract. Acetic acid has been used for decades as an aid for the detection of precancerous cervical lesions, and the use of acetic acid is being investigated in several other tissues. Nonetheless, the mechanism of acetowhitening is unclear. This work tests some of the hypotheses in the literature and measures changes in light scattering specific to the nucleus and the cytoplasm. Wide angle side scattering from both the nucleus and the cytoplasm increases with acetic application to tumorigenic cells, with the increase in nuclear scattering being greater. In one cell line, the changes in nuclear scattering are likely due to an increase in number or scattering efficiency of scattering centers smaller than the wavelength of excitation light. There are likely several cellular changes that cause acetowhitening and the cellular changes may differ with cell type. These results should lead to a better understanding of acetowhitening and potentially the development of adjunct techniques to improve the utility of acetic acid application. For the well-studied case of cervical tissue, acetowhitening has been shown to be sensitive, but not specific for oncogenic changes needing treatment.

Marina, Oana C.; Sanders, Claire K.; Mourant, Judith R.

2012-01-01

121

Effects of acetic acid on light scattering from cells.  

PubMed

Acetic acid has been used for decades as an aid for the detection of precancerous cervical lesions, and the use of acetic acid is being investigated in several other tissues. Nonetheless, the mechanism of acetowhitening is unclear. This work tests some of the hypotheses in the literature and measures changes in light scattering specific to the nucleus and the cytoplasm. Wide angle side scattering from both the nucleus and the cytoplasm increases with acetic application to tumorigenic cells, with the increase in nuclear scattering being greater. In one cell line, the changes in nuclear scattering are likely due to an increase in number or scattering efficiency of scattering centers smaller than the wavelength of excitation light. There are likely several cellular changes that cause acetowhitening and the cellular changes may differ with cell type. These results should lead to a better understanding of acetowhitening and potentially the development of adjunct techniques to improve the utility of acetic acid application. For the well-studied case of cervical tissue, acetowhitening has been shown to be sensitive, but not specific for oncogenic changes needing treatment. PMID:23224185

Marina, Oana C; Sanders, Claire K; Mourant, Judith R

2012-08-01

122

Design and control of acetic acid dehydration system via heterogeneous azeotropic distillation  

Microsoft Academic Search

Acetic acid dehydration is an important operation in the production of aromatic acid, such as terephthalic acid or in the manufacture of cellulose acetate. Although acetic acid and water does not form azeotrope, but using simple distillation to separate these two components is not practical. The reason is because the system has tangent pinch on the pure water end, thus

I. Lung Chien; Kai-Luen Zeng; Huan-Yi Chao; Jun Hong Liu

2004-01-01

123

One carbon metabolism in anaerobic bacteria: Regulation of carbon and electron flow during organic acid production  

Microsoft Academic Search

The project deals with understanding the fundamental biochemical mechanisms that physiologically control and regulate carbon and electron flow in anaerobic chemosynthetic bacteria that couple metabolism of single carbon compounds and hydrogen to the production of organic acids (formic, acetic, butyric, and succinic) or methane. The authors compare the regulation of carbon dioxide and hydrogen metabolism by fermentation, enzyme, and electron

J. G. Zeikus; M. Jain

1993-01-01

124

Production of Menaquinones by Lactic Acid Bacteria  

Microsoft Academic Search

Lactic acid bacteria were examined for their ability to produce quinone compounds, which may include dietary sources of menaquinones. Isoprenyl quinones in bacterial cells grown in a synthetic medium were extracted and analyzed by thin layer chromatography. Lactococcus lactis ssp. cremoris (three strains), Lacto- coccus lactis ssp. lactis (two strains), and Leuconostoc lactis were selected as high producers of quinone

Takashi Morishita; Natsuko Tamura; Takashi Makino; Satoshi Kudo

1999-01-01

125

Probiotic Spectra of Lactic Acid Bacteria (LAB)  

Microsoft Academic Search

Lactic acid bacteria (LAB) and their probio-active cellular substances exert many beneficial effects in the gastrointestinal tract. LAB prevent adherence, establishment, and replication of several enteric mucosal pathogens through several antimicrobial mechanisms. LAB also release various enzymes into the intestinal lumen and exert potential synergistic effects on digestion and alleviate symptoms of intestinal malabsoption. Consumption of LAB fermented dairy products

A. S. Naidu; W. R. Bidlack; R. A. Clemens

1999-01-01

126

Effects of cinnamic acid derivatives on indole acetic acid oxidation by peroxidase  

Microsoft Academic Search

The influence of cinnamic acid derivatives on the H2O2-independent oxidation of indole acetic acid by horseradish peroxidase was examined. Cinnamic acid derivatives show a sharp increase from a slight stimulation of the oxidative reaction to a complete inhibition in a very narrow concentration range. This threshold effect occurs not only for the diphenols caffeic and dihydrocaffeic acids but also for

Regina Volpert; Wolfgang Osswald; Erich F. Elstner

1995-01-01

127

Auto-catalyzed acetic acid pulping of jute  

Microsoft Academic Search

A number of acetic acid (HAc) based pulping trials were carried out to determine the best conditions to produce a jute pulp with low residual lignin content and high physical properties. The extended delignification, with increasing temperature, strongly affected the strength properties. The highest tensile strength of 24Nm\\/g was found at 150°C and 10min, 300ml CSF condition. However, increasing temperature

Halil Turgut Sahin; Raymond A. Young

2008-01-01

128

Dehydration of acetic acid by pervaporation with charged membranes  

Microsoft Academic Search

Modified Nafion membranes were prepared by charging Nafion 117 membrane with different long-chained counter ions and used for pervaporation of acetic acid–water mixture. It was observed, that the selectivity of Nafion membrane was enhanced by charging with long-chained counter ions. However, it led to a decrease in permeate flux because of decreasing solubility and diffusivity of the membranes. The results

Samuel P. Kusumocahyo; Masao Sudoh

1999-01-01

129

Potential energy surfaces for proton abstractions from acetic acid  

Microsoft Academic Search

The abstractions of hydrogen from both carbon and oxygen in acetic acid by hydride, fluoride, and hydroxide anions have been studied using ab initio electronic structure calculations. Molecular structures were optimized at the Hartree-Fock level of theory using the 6-31++G(d,p) basis set. For energetics, the 6-311++G(d,p) basis set was used, with second- and fourth-order perturbation theory corrections, for both minima

Mark S. Gordon; David R. Gano; Eugene Curtiss

1996-01-01

130

Modified alginate composite membranes for the dehydration of acetic acid  

Microsoft Academic Search

Alginate composite membranes cross-linked with 1,6-hexanediamine (HDM) or poly(vinyl alcohol) (PVA) were prepared by casting an aqueous solution of alginate and HDM or PVA on a hydrolyzed microporous polyacrylonitrile (PAN) membrane and characterized by pervaporation separation of acetic acid\\/water mixtures. The influence of hydrolysis of PAN support layer and HDM content in dense layer on separation performance of the composite

Xin-Ping Wang

2000-01-01

131

2-(3-Hy-droxy-benzyl-amino)-acetic acid  

PubMed Central

There are two independent 2-(3-hy­droxy­benzyl­amino)­acetic acid mol­ecules, C9H11NO3, in the asymmetric unit of the title compound. The dihedral angle between the benzene rings of the two independent mol­ecules is 58.12?(4)°. The crystal packing is stablized by inter­molecular O—H?O and N—H?O hydrogen bonds.

Zhi, Li-Hua; Wu, Wei-Na

2011-01-01

132

Electroacupuncture ameliorates experimental colitis induced by acetic acid in rat  

Microsoft Academic Search

The effect of electroacupuncture (EA) on experimental colitis was investigated in Sprague-Dawley rats. Colitis was induced by intracolonic instillation of 4% acetic acid. EA (2 Hz, 0.05 ms, 2 V for 20 min) was applied to bilateral Hoku (LI- 4) and Zusanli (ST-36) on 12 hrs and 36 hrs after induction of colitis. EA-treatment significantly reduced the macroscopic damage and

Jeoung-Woo Kang; Tae-Wan Kim; Jun-Ho La; Tae-Sik Sung; Hyun-Ju Kim; Young-Bae Kwon; Jeum-Yong Kim; Il-Suk Yang

2004-01-01

133

Indole3-acetic acid induces microencephaly in mouse fetuses  

Microsoft Academic Search

To determine the effect of indole-3-acetic acid (IAA), known as natural auxin, on developing fetus, pregnant mice were injected with 500 or 1000mg\\/kg on various gestation days (Days). With the repeated treatment during Days 7–15, the fetal brains exhibited a reduction in size and weight in a dose-dependent manner on Day 18. Histopathologically, hypoplasia of the cortical plate, piriform cortex,

Satoshi Furukawa; Koji Usuda; Masayoshi Abe; Seigo Hayashi; Izumi Ogawa

2007-01-01

134

Fractionation of wheat straw by atmospheric acetic acid process  

Microsoft Academic Search

Fractionation of wheat straw was investigated using an atmospheric acetic acid process. Under the typical conditions of 90% (v\\/v) aqueous AcOH, 4% H2SO4 (w\\/w, on straw), ratio of liquor to straw (L\\/S) 10 (v\\/w), pulping temperature 105°C, and pulping time 3h, wheat straw was fractionated to pulp (cellulose), lignin and monosaccharides mainly from hemicellulose with yields of approximately 50%, 15%

Xuejun Pan; Yoshihiro Sano

2005-01-01

135

75 FR 52269 - Acetic Acid Ethenyl Ester, Polymer With Oxirane; Tolerance Exemption  

Federal Register 2010, 2011, 2012, 2013

...FRL-8841-2] Acetic Acid Ethenyl Ester, Polymer With Oxirane; Tolerance Exemption AGENCY...residues of acetic acid ethenyl ester, polymer with oxirane; when used as an inert ingredient...residues of acetic acid ethenyl ester, polymer with oxirane on food or feed...

2010-08-25

136

Effects of acetic acid treatment on plant chromosome structures analyzed by atomic force microscopy  

Microsoft Academic Search

Acetic acid treatment has been frequently used to remove cellular contaminants from plant chromosome samples for structural analyses by scanning electron microscopy and atomic force microscopy (AFM). We evaluated the effects of various concentrations of acetic acid treatments on barley chromosome structures by using AFM. The long-term 45% acetic acid treatment significantly damaged the chromosome structures, although the treatment effectively

Shigeru Sugiyama; Tomoyuki Yoshino; Hiroko Kanahara; Motoharu Shichiri; Daisuke Fukushi; Toshio Ohtani

2004-01-01

137

Separation of acetic acid-water mixtures by pervaporation through silicalite membrane  

Microsoft Academic Search

Polycrystalline silicalite membranes were prepared on two kinds of porous supports by hydrothermal synthesis. The pervaporation performance of the silicalite membrane obtained was investigated using an acetic acid-water mixture as a feed. The silicalite membrane on the sintered stainless steel support selectively permeates acetic acid in the concentration of the feed acetic acid in the region of 5 to 40

Tsuneji Sano; Shigeyuki Ejiri; Kiyoshi Yamada; Yusuke Kawakami; Hiroshi Yanagishita

1997-01-01

138

Energy metabolism of a unique acetic acid bacterium, Asaia bogorensis, that lacks ethanol oxidation activity.  

PubMed

Acetic acid bacteria (AAB) are known as a vinegar producer on account of their ability to accumulate a high concentration of acetic acid due to oxidative fermentation linking the ethanol oxidation respiratory chain. Reactions in oxidative fermentation cause poor growth because a large amount of the carbon source is oxidized incompletely and the harmful oxidized products are accumulated almost stoichiometrically in the culture medium during growth, but a newly identified AAB, Asaia, has shown unusual properties, including scanty acetic acid production and rapid growth, as compared with known AAB as Acetobacter, Gluconobacter, and Gluconacetobacter. To understand these unique properties of Asaia in more detail, the respiratory chain and energetics of this strain were investigated. It was found that Asaia lacks quinoprotein alcohol dehydrogenase, but has other sugar and sugar alcohol-oxidizing enzymes specific to the respiratory chain of Gluconobacter, especially quinoprotein glycerol dehydrogenase. It was also found that Asaia has a cyanide-sensitive cytochrome bo(3)-type ubiquinol oxidase as sole terminal oxidase in the respiratory chain, and that it exhibits a higher H(+)/O ratio. PMID:18391448

Ano, Yoshitaka; Toyama, Hirohide; Adachi, Osao; Matsushita, Kazunobu

2008-04-07

139

Effect of host diet on production of organic acids and methane by cockroach gut bacteria.  

PubMed Central

The effect of high-fiber diets on microbial populations and processes in cockroach guts was investigated by feeding American cockroaches (Periplaneta americana) milled cereal leaves, milled corn cob, or commercial bran-type breakfast cereal in place of the commonly used laboratory diet of dog chow. The activities and numbers of specific gut bacteria varied significantly with the insect's diet and developmental stage. Acetate and lactate were the principal organic acids present in the gut fluid of adult cockroaches and occurred at concentrations of up to 17 and 8 mM, respectively. These acids were most abundant in the gut fluid of dog chow-fed insects, and the greatest amounts were generally found in the foregut and midgut regions. Foreguts of dog chow-fed cockroaches contained an abundant population of lactic acid bacteria that formed acetate and lactate from endogenous hexoses present in the foregut. When adult cockroaches were fed dog chow amended with antibacterial drugs, (i) the concentrations of acetate, lactate, and total hexoses in gut fluid decreased significantly, (ii) the numbers of lactic acid bacteria in the foregut also decreased significantly, and (iii) the production of acetate and lactate by foregut homogenates was suppressed. It was estimated that acetate and lactate produced by bacteria in the foregut of dog chow-fed adult P. americana could support up to 14% of the insect's respiratory requirement if taken up and used by the animal. When insects were fed high-fiber diets of bran cereal, cereal leaves, or corn cob, bacterial production of acetate and lactate in the foregut diminished.(ABSTRACT TRUNCATED AT 250 WORDS) Images

Kane, M D; Breznak, J A

1991-01-01

140

Autotrophic synthesis of activated acetic acid from two CO 2 in Methanobacterium thermoautotrophicum  

Microsoft Academic Search

An in vitro system of autotropic synthesis of activated acetic acid from14CO2 inMethanobacterium thermoautotrophicum was developed.(1)A recognized14CO2-fixation product in vitro was activated [14C] acetic acid. It could be trapped enzymatically into citrate and released again as [14C] acetate by citrate synthase and citrate lyase, respectively.(2)The synthesis of both activated acetic acid and methane from CO2 proceeded in parallel under a

Erhard Stupperich; Georg Fuchs

1984-01-01

141

Ultrafine cellulose fibers produced by Asaia bogorensis, an acetic acid bacterium.  

PubMed

The ability to synthesize cellulose by Asaia bogorensis, a member of the acetic acid bacteria, was studied in two substrains, AJ and JCM. Although both strains have identical 16S rDNA sequence, only the AJ strain formed a solid pellicle at the air-liquid interface in static culture medium, and we analyzed this pellicle using a variety of techniques. In the presence of cellulase, glucose and cellobiose were released from the pellicle suggesting that it is made of cellulose. Field emission electron microscopy allowed the visualization of a 3D knitted structure with ultrafine microfibrils (approximately 5-20 nm in width) in cellulose from A. bogorensis compared with the 40-100 nm wide microfibrils observed in cellulose isolated from Gluconacetobacter xylinus, suggesting differences in the mechanism of cellulose biosynthesis or organization of cellulose synthesizing sites in these two related bacterial species. Identifying these differences will lead to a better understanding of cellulose biosynthesis in bacteria. PMID:21650167

Kumagai, Akio; Mizuno, Masahiro; Kato, Naoto; Nozaki, Kouichi; Togawa, Eiji; Yamanaka, Shigeru; Okuda, Kazuo; Saxena, Inder M; Amano, Yoshihiko

2011-06-17

142

Ozonation of trichloroethylene in acetic acid solution with soluble and solid humic acid  

Microsoft Academic Search

The combined flushing and oxidation process using acetic acid and ozone has been used successfully to remove trichloroethylene (TCE) completely from contaminated soil. In this study, the effects of humic acid, a fraction of the organic matter in soil, over the performance of TCE decomposition was evaluated. TCE decomposition by ozone was enhanced by the presence of humic acid at

Martha E. Alcántara-Garduño; Tetsuji Okuda; Wataru Nishijima; Mitsumasa Okada

2008-01-01

143

A novel fermentation pathway in an Escherichia coli mutant producing succinic acid, acetic acid, and ethanol.  

SciTech Connect

Escherichia coli strain NZN111, which is unable to grow fermentatively because of insertional inactivation of the genes encoding pyruvate: formate lyase and the fermentative lactate dehydrogenase, gave rise spontaneously to a chromosomal mutation that restored its ability to ferment glucose. The mutant strain, named AFP111, fermented glucose more slowly than did its wild-type ancestor, strain W1485, and generated a very different spectrum of products. AFP111 produced succinic acid, acetic acid, and ethanol in proportions of approx 2:1:1. Calculations of carbon and electron balances accounted fully for the observed products; 1 mol of glucose was converted to 1 mol of succinic acid and 0.5 mol each of acetic acid and ethanol. The data support the emergence in E.coli of a novel succinic acid:acetic acid:ethanol fermentation pathway.

Donnelly, M. I.; Millard, C. S.; Clark, D. P.; Chen, M. J.; Rathke, J. W.; Southern Illinois Univ.

1998-04-01

144

Competitive Oxidation of Volatile Fatty Acids by Sulfate and Nitrate-Reducing Bacteria from an Oil Field in Argentina  

Microsoft Academic Search

Acetate, propionate, and butyrate, collectively referred to as volatile fatty acids (VFA), are considered among the most important electron donors for sulfate-reducing bacteria (SRB) and heterotrophic nitrate-reducing bacteria (hNRB) in oil fields. Samples obtained from a field in the Neuquen Basin, western Argentina, had significant activity of mesophilic SRB, hNRB, and nitrate-reducing, sulfide-oxidizing bacteria (NR-SOB). In microcosms, containing VFA (3

Aleksandr A. Grigoryan; Sabrina L. Cornish; Brenton Buziak; Shiping Lin; Adriana Cavallaro; Joseph J. Arensdorf; Gerrit Voordouw

2008-01-01

145

Genomic organization of lactic acid bacteria  

Microsoft Academic Search

Current knowledge of the genomes of the lactic acid bacteria, Lactococcus lactis and Streptococcus thermophilus, and members of the genera Lactobacillus, Leuconostoc, Pediococcus and Carnobacterium is reviewed. The genomes contain a chromosome within the size range of 1.8 to 3.4 Mbp. Plasmids are common in Lactococcus lactis (most strains carry 4–7 different plasmids), some of the lactobacilli and pediococci, but

Barrie E. Davidson; Nancy Kordias; Marian Dobos; Alan J. Hillier

1996-01-01

146

Production of Formic Acid and Acetic Acid by Hydrothermal Oxidation of Alkali Lignin  

NASA Astrophysics Data System (ADS)

The production of formic acid and acetic acid by hydrothermal oxidation of alkali lignin, a kind of biomasses, was investigated using a batch reactor with H2O2 oxidant. Experiments were performed over a wide range of conditions with temperature varying from 260 to 320° C, oxygen supply varying from 60% to 120%, and reaction time varying from 30 to 150 s. The highest yield of formic acid was 4.9% at 280° C for 120 s with the additive ratio of H2O2 100%. The highest value of acetic acid was 12.3% at 300° C for 120 s with the additive ratio of H2O2 100%. Based on the intermediate products identified by GC/MS and HPLC, reaction pathways of alkali lignin are discussed. It was found that maleic acid and fumaric acid were two primary unsaturated intermediate products. The production of formic acid and acetic acid were come from the oxidative decomposition of intermediate products in the oxidation process. Increasing the formation of saturated dicarboxylic acids and glutaconic acid would enhance the acetic acid yield.

Zeng, Xu; Jin, Fangming; Cao, Jianglin; Yin, Guodong; Zhang, Yalei; Zhao, Jianfu

2010-11-01

147

Direct Determination of Citric Acid in Milk with an Improved Pyridine-Acetic Anhydride Method  

Microsoft Academic Search

SUMMARY The determination of citric acid with pyridine and acetic anhydride has been in- vestigated at reaction temperatures from 17 to 60 ° C. The optimum proportions of pyridine, acetic anhydride, water, and acetic acid for maximum color intensity and stability are given for each temperature. The procedure has been modified to eliminate the violent nature of the reaction, even

J. R. Marier; M. Boulet

1958-01-01

148

[Methanotrophic bacteria of acid sphagnum bogs].  

PubMed

Acid sphagnum bogs cover a considerable part of the territory of Russia and are an important natural source of biogenic methane, which is formed in their anaerobic layers. A considerable portion of this methane is consumed in the aerobic part of the bog profile by acidophilic methanotrophic bacteria, which comprise the methane filter of sphagnum bogs and decrease CH4 emission to the atmosphere. For a long time, these bacteria escaped isolation, which became possible only after the elucidation of the optimal conditions of their functioning in situ: pH 4.5 to 5.5; temperature, from 15 to 20 degrees C; and low salt concentration in the solution. Reproduction of these conditions and rejection of earlier used media with a high content of biogenic elements allowed methanotrophic bacteria of two new genera and species--Methylocella palustris and Methylocapsa acidophila--to be isolated from the peat of sphagnum bogs of the northern part of European Russia and West Siberia. These bacteria are well adapted to the conditions in cold, acid, oligotrophic sphagnum bogs. They grow in a pH range of 4.2-7.5 with an optimum at 5.0-5.5, prefer moderate temperatures (15-25 degrees C) and media with a low content of mineral salts (200-500 mg/l), and are capable of active nitrogen fixation. Design of fluorescently labeled 16S rRNA-targeted oligonucleotide probes for the detection of Methylocella palustris and Methylocapsa acidophila and their application to the analysis of sphagnum peat samples showed that these bacteria represent dominant populations of methanotrophs with a density of 10(5)-10(6) cells/g peat. In addition to Methylocella and Methylocapsa populations, one more abundant population of methanotrophs was revealed (10(6) cells/g peat), which were phylogenetically close to the genus Methylocystis. PMID:12526194

Dedysh, S N

149

Atmospheric Acetic Acid Pulping of Rice Straw II: Behavior of Ash and Silica in Rice Straw during Atmospheric Acetic Acid Pulping and Bleaching  

Microsoft Academic Search

Summary A detailed examination was made of the behavior and distribution of ash and silica during atmospheric acetic acid pulping and subsequent bleaching of rice straw. Ash-rich pulps (in unbleached pulp, about 18 %; and in bleached pulp, 16 %) with matchable strength properties for conventional alkaline pulps were obtained from rice straw by acetic acid pulping. More than 50

Xue-Jun Pan; Yoshihiro Sano; Toshiaki Ito

1999-01-01

150

Indole 3-acetic acid production by ectomycorrhizal fungi.  

PubMed

Ability of 8 ectomycorrhizal fungi to synthesise indole 3-acetic acid from L-tryptophan and their growth rate were studied. Differences in the levels of IAA synthesis and biomass production among the 8 mycorrhizal fungi were observed. A positive correlation was recorded between IAA level and mycelial growth. The synthesis of IAA and mycelial biomass were maximum on 30th day after incubation. Pisolithus tinctorius and Laccaria laccata exhibited higher amounts of IAA production than other fungi, whereas Amanita muscaria and Rhizopogon luteolus showed least quantity of IAA. PMID:1521864

Gopinathan, S; Raman, N

1992-02-01

151

Kinetic Modeling of Esterification of Ethylene Glycol with Acetic Acid  

SciTech Connect

The reaction kinetics of the esterification of ethylene glycol with acetic acid in the presence of cation exchange resin has been studied and kinetic models based on empirical and Langmuir approach has been developed. The Langmuir based model involving eight kinetic parameters fits experimental data much better compared to empirical model involving four kinetic parameters. The effect of temperature and catalyst loading on the reaction system has been analyzed. Further, the activation energy and frequency factor of the rate constants for Langmuir based model has been estimated.

Yadav, Vishnu P.; Maity, Sunil K. [Department of Chemical Engineering, Indian Institute of Technology, Hyderabad, Ordnance Factory Estate, Yeddumailiram-502205, Andhra Pradesh (India); Mukherjee, Rudra Palash [Department of Chemical Engineering, National Institute of Technology, Durgapur, Mahatma Gandhi Avenue, Durgapur-713209, West Bengal (India); Bantraj, Kandi [Department of Chemical Engineering, National Institute of Technology, Rourkela-769008, Orissa (India)

2010-10-26

152

Gluconacetobacter kakiaceti sp. nov., an acetic acid bacterium isolated from a traditional Japanese fruit vinegar.  

PubMed

Two novel acetic acid bacteria, strains G5-1(T) and I5-1, were isolated from traditional kaki vinegar (produced from fruits of kaki, Diospyros kaki Thunb.), collected in Kumamoto Prefecture, Japan. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strains G5-1(T) and I5-1 formed a distinct subline in the genus Gluconacetobacter and were closely related to Gluconacetobacter swingsii DST GL01(T) (99.3% 16S rRNA gene sequence similarity). The isolates showed 96-100% DNA-DNA relatedness with each other, but <53% DNA-DNA relatedness with closely related members of the genus Gluconacetobacter. The isolates could be distinguished from closely related members of the genus Gluconacetobacter by not producing 2- and 5-ketogluconic acids from glucose, producing cellulose, growing without acetic acid and with 30% (w/v) d-glucose, and producing acid from sugars and alcohols. Furthermore, the genomic DNA G+C contents of strains G5-1(T) and I5-1 were a little higher than those of their closest phylogenetic neighbours. On the basis of the phenotypic characteristics and phylogenetic position, strains G5-1(T) and I5-1 are assigned to a novel species, for which the name Gluconacetobacter kakiaceti sp. nov. is proposed; the type strain is G5-1(T) (=JCM 25156(T)=NRIC 0798(T)=LMG 26206(T)). PMID:21841006

Iino, Takao; Suzuki, Rei; Tanaka, Naoto; Kosako, Yoshimasa; Ohkuma, Moriya; Komagata, Kazuo; Uchimura, Tai

2011-08-12

153

Acetic acid production from lactose by an anaerobic thermophilic coculture immobilized in a fibrous-bed bioreactor.  

PubMed

An anaerobic thermophilic coculture consisting of a heterofermentative bacterium (Clostridium thermolacticum) and a homoacetogen (Moorella thermoautotrophica) was developed for acetic acid production from lactose and milk permeate. The fermentation kinetics with free cells in conventional fermentors and immobilized cells in a recycle batch fibrous-bed bioreactor were studied. The optimal conditions for the cocultured fermentation were found to be 58 degrees C and pH 6.4. In the free-cell fermentation, C. thermolacticum converted lactose to acetate, ethanol, lactate, H(2) and CO(2), and the homoacetogen then converted lactate, H(2), and CO(2) to acetate. The overall acetate yield from lactose ranged from 0.46 to 0.65 g/g lactose fermented, depending on the fermentation conditions. In contrast, no ethanol was produced in the immobilized-cell fermentation, and the overall acetate yield from lactose increased to 0.8-0.96 g/g lactose fermented. The fibrous-bed bioreactor also gave a higher final acetate concentration (up to 25. 5 g/L) and reactor productivity (0.18-0.54 g/L/h) as compared to those from the free-cell fermentation (final acetate concentration, 15 g/L; productivity, 0.06-0.08 g/L/h). The superior performance of the fibrous-bed bioreactor was attributed to the high cell density (20 g/L) immobilized in the fibrous-bed and adaptation of C. thermolacticum cells to tolerate a higher acetate concentration. The effects of yeast extract and trypticase as nutrient supplements on the fermentation were also studied. For the free-cell fermentation, nutrient supplementation was necessary for the bacteria to grow in milk permeate. For the immobilized-cell fermentation, plain milk permeate gave a high acetate yield (0.96 g/g), although the reactor productivity was lower than those with nutrient supplementation. Balanced growth and fermentation activities between the two bacteria in the coculture are important to the quantitative conversion of lactose to acetic acid. Lactate and hydrogen produced by C. thermolacticum must be timely converted to acetic acid by the homoacetogen to avoid inhibition by these metabolites. PMID:11101328

Talabardon, M; Schwitzguébel, J P; Péringer, P; Yang, S T

154

High efficiency recombineering in lactic acid bacteria  

PubMed Central

The ability to efficiently generate targeted point mutations in the chromosome without the need for antibiotics, or other means of selection, is a powerful strategy for genome engineering. Although oligonucleotide-mediated recombineering (ssDNA recombineering) has been utilized in Escherichia coli for over a decade, the successful adaptation of ssDNA recombineering to Gram-positive bacteria has not been reported. Here we describe the development and application of ssDNA recombineering in lactic acid bacteria. Mutations were incorporated in the chromosome of Lactobacillus reuteri and Lactococcus lactis without selection at frequencies ranging between 0.4% and 19%. Whole genome sequence analysis showed that ssDNA recombineering is specific and not hypermutagenic. To highlight the utility of ssDNA recombineering we reduced the intrinsic vancomymycin resistance of L. reuteri >100-fold. By creating a single amino acid change in the d-Ala-d-Ala ligase enzyme we reduced the minimum inhibitory concentration for vancomycin from >256 to 1.5?µg/ml, well below the clinically relevant minimum inhibitory concentration. Recombineering thus allows high efficiency mutagenesis in lactobacilli and lactococci, and may be used to further enhance beneficial properties and safety of strains used in medicine and industry. We expect that this work will serve as a blueprint for the adaptation of ssDNA recombineering to other Gram-positive bacteria.

van Pijkeren, Jan-Peter; Britton, Robert A.

2012-01-01

155

Effects of petroleum hydrocarbons on the phospholipid fatty acid composition of a consortium composed of marine hydrocarbon-degrading bacteria  

Microsoft Academic Search

Phospholipid ester-linked fatty acids (PLFAs) of a bacteria consortium, reconstituted in vitro from ten marine hydrocarbon-degrading bacteria, were studied. Culture of the consortium with ammonium acetate as the sole carbon source mainly yielded even-numbered PLFAs composed of straight chain saturated (ca. 26%) and monounsaturated (ca. 71%) fatty acids. Growth of the consortium on Blend Arabian Light petroleum (BAL 250) resulted

E Aries; P Doumenq; J Artaud; M Acquaviva; J. C Bertrand

2001-01-01

156

Oxidation of indole-3-acetic acid to oxindole-3-acetic acid by etiolated and green corn tissues  

SciTech Connect

Etiolated corn tissues oxidase indole-3-acetic acid (IAA) to oxindole-3-acetic acid (OxIAA). This oxidation results in loss of auxin activity and may plant a role in regulating IAA-stimulated growth. The enzyme has been partially purified and characterized and shown to require O{sub 2}, and a heat-stable lipid-soluble corn factor which can be replaced by linolenic or linoleic acids in the oxidation of IAA. Corn oil was tested as a cofactor in the IAA oxidation reaction. Corn oil stimulated enzyme activity by 30% while trilinolein was inactive. The capacity of green tissue to oxidize IAA was examined by incubating leaf sections from 2 week old light-grown corn seedlings with {sup 14}C-IAA. OxIAA and IAA were separated from other IAA metabolites on a 3 ml anion exchange column. Of the IAA taken up by the sections, 13% was oxidized to OxIAA. This is the first evidence that green tissue of corn may also regulate IAA levels by oxidizing IAA to OxIAA.

Reinecke, D. (Michigan State Univ., East Lansing (USA))

1989-04-01

157

Bacteriocins of lactic acid bacteria: Their potentials as food biopreservative  

Microsoft Academic Search

Numerous strains of lactic acid bacteria used in the fermentation of foods are known to produce bacteriocins. In general, bacteriocins are a group of proteinaceous antimicrobial substances that inhibit the growth of closely related bacteria. However, some bacteriocins produced by lactic acid bacteria (LAB) exhibit a relatively broad antimicrobial spectrum and are active against several food?spoilage and health?threatening microorganisms. Many

Wang June Kim

1993-01-01

158

Lactic acid bacteria of meat and meat products  

Microsoft Academic Search

When the growth of aerobic spoilage bacteria is inhibited, lactic acid bacteria may become the dominant component of the microbial flora of meats. This occurs with cured meats and with meats packaged in films of low gas permeability. The presence of a flora of psychrotrophic lactic acid bacteria on vacuum-packaged fresh chilled meats usually ensures that shelf-life is maximal. When

Aubrey F. Egan

1983-01-01

159

Clostridium strain which produces acetic acid from waste gases  

DOEpatents

A method and apparatus are disclosed for converting waste gases from industrial processes such as oil refining, carbon black, coke, ammonia, and methanol production, into useful products. The method includes introducing the waste gases into a bioreactor where they are fermented to various organic acids or alcohols by anaerobic bacteria within the bioreactor. These valuable end products are then recovered, separated and purified. In an exemplary recovery process, the bioreactor raffinate is passed through an extraction chamber into which one or more non-inhibitory solvents are simultaneously introduced to extract the product. Then, the product is separated from the solvent by distillation. Gas conversion rates can be maximized by use of centrifuges, hollow fiber membranes, or other means of ultrafiltration to return entrained anaerobic bacteria from the bioreactor raffinate to the bioreactor itself, thus insuring the highest possible cell concentration. 4 figs.

Gaddy, J.L.

1997-01-14

160

Antimicrobial Effects of Mustard Flour and Acetic Acid against Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella enterica Serovar Typhimurium  

PubMed Central

This study was designed to investigate the individual and combined effects of mustard flour and acetic acid in the inactivation of food-borne pathogenic bacteria stored at 5 and 22°C. Samples were prepared to achieve various concentrations by the addition of acetic acid (0, 0.5, or 1%) along with mustard flour (0, 10, or 20%) and 2% sodium chloride (fixed amount). Acid-adapted three-strain mixtures of Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella enterica serovar Typhimurium strains (106 to 107 CFU/ml) were inoculated separately into prepared mustard samples stored at 5 and 22°C, and samples were assayed periodically. The order of bacterial resistance, assessed by the time required for the nominated populations to be reduced to undetectable levels against prepared mustards at 5°C, was S. enterica serovar Typhimurium (1 day) < E. coli O157:H7 (3 days) < L. monocytogenes (9 days). The food-borne pathogens tested were reduced much more rapidly at 22°C than at 5°C. There was no synergistic effect with regard to the killing of the pathogens tested with the addition of 0.5% acetic acid to the mustard flour (10 or 20%). Mustard in combination with 0.5% acetic acid had less bactericidal activity against the pathogens tested than did mustard alone. The reduction of E. coli O157:H7 and L. monocytogenes among the combined treatments on the same storage day was generally differentiated as follows: control < mustard in combination with 0.5% acetic acid < mustard alone < mustard in combination with 1% acetic acid < acetic acid alone. Our study indicates that acidic products may limit microbial growth or survival and that the addition of small amounts of acetic acid (0.5%) to mustard can retard the reduction of E. coli O157:H7 and L. monocytogenes. These antagonistic effects may be changed if mustard is used alone or in combination with >1% acetic acid.

Rhee, Min-Suk; Lee, Sun-Young; Dougherty, Richard H.; Kang, Dong-Hyun

2003-01-01

161

Boswellic acid acetate induces apoptosis through caspase-mediated pathways in myeloid leukemia cells.  

PubMed

The mechanism of the cytotoxic effect of boswellic acid acetate, a 1:1 mixture of alpha-boswellic acid acetate and beta-boswellic acid acetate, isolated from Boswellia carterri Birdw on myeloid leukemia cells was investigated in six human myeloid leukemia cell lines (NB4, SKNO-1, K562, U937, ML-1, and HL-60 cells). Morphologic and DNA fragmentation assays indicated that the cytotoxic effect of boswellic acid acetate was mediated by induction of apoptosis. More than 50% of the cells underwent apoptosis after treatment with 20 mug/mL boswellic acid for 24 hours. This apoptotic process was p53 independent. The levels of apoptosis-related proteins Bcl-2, Bax, and Bcl-XL were not modulated by boswellic acid acetate. Boswellic acid acetate induced Bid cleavage and decreased mitochondrial membrane potential without production of hydrogen peroxide. A general caspase inhibitor (Z-VAD-FMK) and a specific caspase-8 inhibitor II (Z-IETD-FMK) blocked boswellic acid acetate-induced apoptosis. The mRNAs of death receptors 4 and 5 (DR4 and DR5) were induced in leukemia cells undergoing apoptosis after boswellic acid acetate treatment. These data taken together suggest that boswellic acid acetate induces myeloid leukemia cell apoptosis through activation of caspase-8 by induced expression of DR4 and DR5, and that the activated caspase-8 either directly activates caspase-3 by cleavage or indirectly by cleaving Bid, which in turn decreases mitochondria membrane potential. PMID:15767547

Xia, Lijuan; Chen, Duo; Han, Rui; Fang, Qicheng; Waxman, Samuel; Jing, Yongkui

2005-03-01

162

Polyunsaturated fatty acid production by marine bacteria.  

PubMed

Polyunsaturated fatty acids are important in maintaining human health. Limitations associated with current sources of ?-3 fatty acids and ?-6 fatty acids, from animal and plant sources, have led to increased interest in microbial production. Marine bacteria may provide a suitable alternative, although the isolation of production strains and the identification of operating conditions must be addressed before manufacturing processes become economically viable. Marine isolate 560 was identified as an eicosapentaenoic acid (EPA) producer via GC/MS. The isolate was initially identified as Vibrio cyclitrophicus by 16S rRNA sequencing. Statistically based experimental designs were applied to the optimisation of medium components and environmental factors for the production of EPA. A Plackett-Burman design was used to screen for the effect of temperature, pH, and media components. Subsequently, the concentrations of NaCl, yeast extract, and peptone, identified as significant factors, were optimised using a central composite design. The predicted optimal combination of media components for maximum EPA production (4.8 mg/g dry weight) was determined as 7.9 g/l peptone, 16.2 g/l NaCl, and 6.2 g/l yeast extract. On transfer of this process to bioreactor cultivation, where a range of pH and DO values were tested, the maximum amount of EPA produced increased to 7.5 mg/g dry weight and 10 % of the total fatty acid. PMID:23525832

Abd Elrazak, Ahmed; Ward, Alan C; Glassey, Jarka

2013-03-23

163

Ozonation of trichloroethylene in acetic acid solution with soluble and solid humic acid.  

PubMed

The combined flushing and oxidation process using acetic acid and ozone has been used successfully to remove trichloroethylene (TCE) completely from contaminated soil. In this study, the effects of humic acid, a fraction of the organic matter in soil, over the performance of TCE decomposition was evaluated. TCE decomposition by ozone was enhanced by the presence of humic acid at concentrations lower than 8mgCL(-1) and then inhibited at higher concentrations. It is possible that the presence of the soluble humic acid fraction during the ozonation of TCE in acetic acid solutions produces hydroxyl radicals during the TCE ozonation which appears to be the reason for the enhanced TCE decomposition rate. Solid humic acid reduced TCE decomposition rate by acting as an ozone scavenger. Similarly, sorbed TCE reduced the amount of TCE available for decomposition by ozone in solution. PMID:18511186

Alcántara-Garduño, Martha E; Okuda, Tetsuji; Nishijima, Wataru; Okada, Mitsumasa

2008-03-30

164

Toxicokinetics and Oral Bioavailability of Halogenated Acetic Acids Mixtures in Naive and GSTzeta-Depleted Rats  

Microsoft Academic Search

Pharmacokinetics of halogenated acetic acid (HAA) mixtures in native and GSTzeta depleted rats was investigated. Rats were administered orally or i.v. to Mixture-1 (monobromo- dichloro-, chlorodibromo-, tribromo- acetic acids) or Mixture-2 (bromochloro-, dibromo-, trichloro- bromodichloro- acetic acids) at a dose of 25 ?mol\\/kg HAA and blood samples collected up to 36 h. GSTzeta depleted rats were also orally dosed with

Shakil A. Saghir; Irvin R. Schultz

2005-01-01

165

Antimould activity of sourdough lactic acid bacteria: identification of a mixture of organic acids produced by Lactobacillus sanfrancisco CB1  

Microsoft Academic Search

Sourdough lactic acid bacteria, cultivated in wheat flour hydrolysate, produced antimould compounds. The antimould activity\\u000a varied greatly among the strains and was mainly detected within obligately heterofermentative Lactobacillus spp. Among these, Lb. sanfrancisco CB1 had the largest spectrum. It inhibited moulds related to bread spoilage such as Fusarium, Penicillium, Aspergillus and Monilia. A mixture of acetic, caproic, formic, propionic, butyric

A. Corsetti; M. Gobbetti; J. Rossi; P. Damiani

1998-01-01

166

Corrosion behavior of mild steel in acetic acid solutions  

SciTech Connect

The corrosion behavior of mild steel in acetic acid (CH{sub 3}COOH) solutions was studied by weight loss and potentiostatic polarization techniques. The variation in corrosion rate of mild steel with concentrations of CH{sub 3}COOH, evaluated by weight loss and electrochemical techniques, showed marked resemblance. From both techniques, the maximum corrosion rate was observed for 20% CH{sub 3}COOH solution at all three experimental temperatures (25, 35, and 45 C). Anodic polarization curves showed active-passive behavior at each concentration, except at 80% CH{sub 3}COOH. Critical current density (i{sub c}) passive current density (I{sub n}), primary passivation potential (E{sub pp}), and potential for passivity (E{sub p}) had their highest values in 20% CH{sub 3}COOH solution. With an increase in temperature, while the anodic polarization curves shifted toward higher current density region at each concentration, the passive region became progressively less distinguishable. With the addition of sodium acetate (NaCOOCH{sub 3}) as a supporting electrolyte, the passive range was enlarged substantially. However, the transpassive region commenced at more or less the same potential. Cathodic polarization curves were almost identical irrespective of the concentration of CH{sub 3}COOH or temperature.

Singh, M.M.; Gupta, A.

2000-04-01

167

Characterisation of lactic acid bacteria isolated from fermented milk "laban".  

PubMed

The technological properties of 96 lactic acid bacteria isolated from Lebanese traditional fermented milk "laban" were characterised. They were classified by phenotypic and biochemical analyses as Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus, thus indicating that laban is a fermented milk similar to yogurt. Most strains of L. bulgaricus (87.5%) exhibited a high acidification activity, whereas strains of streptococci showed low acidification ability. 33.3% of streptococci strains and 25% of lactobacilli strains displayed similar acidification performances as European strains. Results obtained for syneresis, texture and rheological parameters led us to consider that isolated strains were not low polymer-producing strains. Some of them displayed interesting characteristics such as low syneresis and high values for rheological parameters. The major flavour compounds found in pure cultures were acetaldehyde, acetone, 2-butanone, dimethyl disulfide, acetoin, 2,3-butanedione, 2,3-pentanedione, and acetic, hexanoic and butanoic acids. Acetaldehyde (7.4%) and organic acids (48.3%) were mainly produced by L. bulgaricus strains, whereas streptococci cultures contained high relative levels of 2,3-butanedione and acetoin, which represented around 82% of the total flavour compounds. Finally, strains isolated from laban samples exhibited different technological properties than those used in yogurt production, thus conferring specific characteristics to this product. PMID:16701913

Chammas, Gisele I; Saliba, Rachad; Corrieu, Georges; Béal, Catherine

2006-05-15

168

Genome-wide identification of Saccharomyces cerevisiae genes required for tolerance to acetic acid  

Microsoft Academic Search

BACKGROUND: Acetic acid is a byproduct of Saccharomyces cerevisiae alcoholic fermentation. Together with high concentrations of ethanol and other toxic metabolites, acetic acid may contribute to fermentation arrest and reduced ethanol productivity. This weak acid is also a present in lignocellulosic hydrolysates, a highly interesting non-feedstock substrate in industrial biotechnology. Therefore, the better understanding of the molecular mechanisms underlying S.

Nuno P Mira; Margarida Palma; Joana F Guerreiro; Isabel Sá-Correia

2010-01-01

169

Development of Acetic Acid Removal Technology for the UREX+Process  

SciTech Connect

It is imperative that acetic acid is removed from a waste stream in the UREX+process so that nitric acid can be recycled and possible interference with downstreatm steps can be avoidec. Acetic acid arises from acetohydrozamic acid (AHA), and is used to suppress plutonium in the first step of the UREX+process. Later, it is hydrolyzed into hydroxyl amine nitrate and acetic acid. Many common separation technologies were examined, and solvent extraction was determined to be the best choice under process conditions. Solvents already used in the UREX+ process were then tested to determine if they would be sufficient for the removal of acetic acid. The tributyl phosphage (TBP)-dodecane diluent, used in both UREX and NPEX, was determined to be a solvent system that gave sufficient distribution coefficients for acetic acid in addition to a high separation factor from nitric acid.

Robert M. Counce; Jack S. Watson

2009-06-30

170

Leaching of spent lead acid battery paste components by sodium citrate and acetic acid.  

PubMed

A sustainable method, with minimal pollution and low energy cost in comparison with the conventional smelting methods, is proposed for treating components of spent lead-acid battery pastes in aqueous organic acid(s). In this study, PbO, PbO2, and PbSO4, the three major components in a spent lead paste, were individually reacted with a mixture of aqueous sodium citrate and acetic acid solution. Pure lead citrate precursor of Pb3(C6H5O7)2 · 3H2O is the only product crystallized in each leaching experiment. Conditions were optimized for individual lead compounds which were then used as the basis for leaching real industrial spent paste. In this work, efficient leaching process is achieved and raw material cost is reduced by using aqueous sodium citrate and acetic acid, instead of aqueous sodium citrate and citric acid as reported in a pioneering hydrometallurgical method earlier. Acetic acid is not only cheaper than citric acid but is also more effective in aiding dissolution of the lead compounds thus speeding up the leaching process in comparison with citric acid. Lead citrate is readily crystallized from the aqueous solution due to its low solubility and can be combusted to directly produce leady oxide as a precursor for making new battery pastes. PMID:23500418

Zhu, Xinfeng; He, Xiong; Yang, Jiakuan; Gao, Linxia; Liu, Jianwen; Yang, Danni; Sun, Xiaojuan; Zhang, Wei; Wang, Qin; Kumar, R Vasant

2013-02-19

171

Formation of formic acid, acetic acid and lactic acid from decomposition of citric acid by coal ash particles at room temperature  

Microsoft Academic Search

It was found for the first time that citric acid was decomposed to formic acid, acetic acid and lactic acid in the presence of coal ash particles at pH 3 at 20°C, while it was not decomposed at more than pH 5. The yield of organic acid at stirring time of 60min is in the order of formic acid>acetic acid>lactic

Hiroyuki Nakui; Kenji Okitsu; Yasuaki Maeda; Rokuro Nishimura

2009-01-01

172

Isolation of a new lytic enzyme for hiochi bacteria and other lactic acid bacteria  

Microsoft Academic Search

A microorganism producing a lytic enzyme preparation that could rapidly lyse bacterial cells such as hiochi bacteria and other lactic acid bacteria was screened. The microorganism was identified as Streptomyces fulvissimus. The enzyme produced by this organism lysed boil-denatured cells quicker than intact cells of hiochi bacteria. A mutant strain of S. fulvissimus producing the enzyme exhibiting high activity against

Kazuhiko Ohbuchi; Kazuya Hasegawa; Masaaki Hamachi; Kenji Ozeki; Chieko Kumagai

2001-01-01

173

Endohyphal bacterium enhances production of indole-3-acetic Acid by a foliar fungal endophyte.  

PubMed

Numerous plant pathogens, rhizosphere symbionts, and endophytic bacteria and yeasts produce the important phytohormone indole-3-acetic acid (IAA), often with profound effects on host plants. However, to date IAA production has not been documented among foliar endophytes -- the diverse guild of primarily filamentous Ascomycota that live within healthy, above-ground tissues of all plant species studied thus far. Recently bacteria that live within hyphae of endophytes (endohyphal bacteria) have been detected, but their effects have not been studied previously. Here we show not only that IAA is produced in vitro by a foliar endophyte (here identified as Pestalotiopsis aff. neglecta, Xylariales), but that IAA production is enhanced significantly when the endophyte hosts an endohyphal bacterium (here identified as Luteibacter sp., Xanthomonadales). Both the endophyte and the endophyte/bacterium complex appear to rely on an L-tryptophan dependent pathway for IAA synthesis. The bacterium can be isolated from the fungus when the symbiotic complex is cultivated at 36°C. In pure culture the bacterium does not produce IAA. Culture filtrate from the endophyte-bacterium complex significantly enhances growth of tomato in vitro relative to controls and to filtrate from the endophyte alone. Together these results speak to a facultative symbiosis between an endophyte and endohyphal bacterium that strongly influences IAA production, providing a new framework in which to explore endophyte-plant interactions. PMID:24086270

Hoffman, Michele T; Gunatilaka, Malkanthi K; Wijeratne, Kithsiri; Gunatilaka, Leslie; Arnold, A Elizabeth

2013-09-24

174

Utilization of the plant hormone indole-3-acetic acid for growth by Pseudomonas putida strain 1290.  

PubMed

We have isolated from plant surfaces several bacteria with the ability to catabolize indole-3-acetic acid (IAA). One of them, isolate 1290, was able to utilize IAA as a sole source of carbon, nitrogen, and energy. The strain was identified by its 16S rRNA sequence as Pseudomonas putida. Activity of the enzyme catechol 1,2-dioxygenase was induced during growth on IAA, suggesting that catechol is an intermediate of the IAA catabolic pathway. This was in agreement with the observation that the oxygen uptake by IAA-grown P. putida 1290 cells was elevated in response to the addition of catechol. The inability of a catR mutant of P. putida 1290 to grow at the expense of IAA also suggests a central role for catechol as an intermediate in IAA metabolism. Besides being able to destroy IAA, strain 1290 was also capable of producing IAA in media supplemented with tryptophan. In root elongation assays, P. putida strain 1290 completely abolished the inhibitory effect of exogenous IAA on the elongation of radish roots. In fact, coinoculation of roots with P. putida 1290 and 1 mM concentration of IAA had a positive effect on root development. In coinoculation experiments on radish roots, strain 1290 was only partially able to alleviate the inhibitory effect of bacteria that in culture overproduce IAA. Our findings imply a biological role for strain 1290 as a sink or recycler of IAA in its association with plants and plant-associated bacteria. PMID:15870323

Leveau, Johan H J; Lindow, Steven E

2005-05-01

175

Endohyphal Bacterium Enhances Production of Indole-3-Acetic Acid by a Foliar Fungal Endophyte  

PubMed Central

Numerous plant pathogens, rhizosphere symbionts, and endophytic bacteria and yeasts produce the important phytohormone indole-3-acetic acid (IAA), often with profound effects on host plants. However, to date IAA production has not been documented among foliar endophytes -- the diverse guild of primarily filamentous Ascomycota that live within healthy, above-ground tissues of all plant species studied thus far. Recently bacteria that live within hyphae of endophytes (endohyphal bacteria) have been detected, but their effects have not been studied previously. Here we show not only that IAA is produced in vitro by a foliar endophyte (here identified as Pestalotiopsis aff. neglecta, Xylariales), but that IAA production is enhanced significantly when the endophyte hosts an endohyphal bacterium (here identified as Luteibacter sp., Xanthomonadales). Both the endophyte and the endophyte/bacterium complex appear to rely on an L-tryptophan dependent pathway for IAA synthesis. The bacterium can be isolated from the fungus when the symbiotic complex is cultivated at 36°C. In pure culture the bacterium does not produce IAA. Culture filtrate from the endophyte-bacterium complex significantly enhances growth of tomato in vitro relative to controls and to filtrate from the endophyte alone. Together these results speak to a facultative symbiosis between an endophyte and endohyphal bacterium that strongly influences IAA production, providing a new framework in which to explore endophyte-plant interactions.

Hoffman, Michele T.; Gunatilaka, Malkanthi K.; Wijeratne, Kithsiri; Gunatilaka, Leslie; Arnold, A. Elizabeth

2013-01-01

176

Phase Preference by Active, Acetate-Utilizing Bacteria at the Rifle, CO Integrated Field Research Challenge Site  

SciTech Connect

Uranium contaminated groundwaters are a legacy concern for the U.S. Department of Energy. Previous experiments at the Rifle, Colorado Integrated Field Challenge (IFC) site have demonstrated that field-scale addition of acetate to groundwater reduces the ambient soluable uranium concentration, sequestering the radionuclide as uraninite. However, questions remain regarding which microorganism(s) are consuming this acetate and if active groundwater microorganisms are different from active particle-associated bacteria. In this report, 13-C acetate was used to assess the active microbes that synthesize DNA on 3 size fractions [coarse sand, fines (8-approximately 150 micron), groundwater (0.2-8 micron)] over a 24 -day time frame. Results indicated a stronger signal from 13-C acetate associated with the “fines” fraction compared with smaller amounts of 13-C uptake on the sand fraction and groundwater samples during the SIP incubations. TRFLP analysis of this 13-C-labeled DNA, indicated 31+ 9 OTU's with 6 peaks dominating the active profiles (166, 187, 210, 212, and 277 bp peaks using MnlI). Cloning/sequencing of the amplification products indicated a Geobacter-like group (187, 210, 212 bp) primarily synthesized DNA from acetate in the groundwater phase, an alpha Proteobacterium (166 bp) primarily grew on the fines/sands, and an Acinetobacter sp. (277 bp) utilized much of the 13C acetate in both groundwater and particle-associated phases. These findings will help to delineate the acetate utilization patterns of bacteria during field-scale acetate addition and can lead to improved methods for stimulating distinct microbial populations in situ.

Kerkhoff, Lee; Williams, Kenneth H.; Long, Philip E.; McGuinness, L.

2011-02-15

177

Titanium (IV)Improved H2O2\\/O3 Process for Acetic Acid Degradation under Acid Conditions  

Microsoft Academic Search

The effect of Ti(IV) on the degradation efficiency of acetic acid by O3\\/H2O2 was investigated. The removal rate of acetic acid by O3\\/H2O2 increased from 8.0% to 62.9% after 30 min when Ti(IV) was added to acetic acid solution at pH 2.8. The optimized parameters were as follows: the pH of acetic acid solution less than 5.0; the mass concentration

Shao-Ping Tong; Wen-wen Li; Shu-qin Zhao; Chun-an Ma

2011-01-01

178

Gluconacetobacter maltaceti sp. nov., a novel vinegar producing acetic acid bacterium.  

PubMed

Comparison of HaeIII- and HpaII-restriction profiles of PCR-amplified 16S-23S rDNA ITS regions of Gluconacetobacter sp. LMG 1529(T) and SKU 1109 with restriction profiles of reference strains of acetic acid bacteria described by Tr?ek and Teuber [34] revealed the same but unique restriction profiles for LMG 1529(T) and SKU 1109. Further analyses of nearly complete 16S rRNA gene sequences, nearly complete 16S-23S rDNA ITS sequences, as well as concatenated partial sequences of the housekeeping genes dnaK, groEL and rpoB, allocated both strains to a single phylogenetic cluster well separated from the other species of the genus Gluconacetobacter. DNA-DNA hybridizations confirmed their novel species identity by 73% DNA-DNA relatedness between both strains, and values below the species level (<70%) between SKU 1109 and the type strains of the closest phylogenetic neighbors. The classification of strains LMG 1529(T) and SKU 1109 into a single novel species was confirmed also by AFLP and (GTG)(5)-PCR DNA fingerprinting data, as well as by phenotypic data. Strains LMG 1529(T) and SKU 1109 can be differentiated from their closely related Gluconacetobacter species, Gluconacetobacter entanii and Gluconacetobacter hansenii, by their ability to form 2-keto-d-gluconic acid from d-glucose, their ability to use d-mannitol, d-gluconate and glycerol as carbon source and form acid from d-fructose, and their ability to grow without acetic acid. The major fatty acid of LMG 1529(T) and SKU 1109 is C(18:1?7c) (60.2-64.8%). The DNA G+C content of LMG 1529(T) and SKU 1109 is 62.5 and 63.3mol% respectively. The name Gluconacetobacter maltaceti sp. nov. is proposed. The type strain is LMG 1529(T) (=NBRC 14815(T)=NCIMB 8752(T)). PMID:23273842

Slapšak, Nina; Cleenwerck, Ilse; De Vos, Paul; Tr?ek, Janja

2012-12-27

179

Phase Preference by Active, Acetate-Utilizing Bacteria at the Rifle, CO Integrated Field Research Challenge Site  

SciTech Connect

Previous experiments at the Rifle, Colorado Integrated Field Research Challenge (IFRC) site demonstrated that field-scale addition of acetate to groundwater reduced the ambient soluble uranium concentration. In this report, sediment samples collected before and after acetate field addition were used to assess the active microbes via {sup 13}C acetate stable isotope probing on 3 phases [coarse sand, fines (8-approximately 150 {micro}m), groundwater (0.2-8 {micro}m)] over a 24-day time frame. TRFLP results generally indicated a stronger signal in {sup 13}C-DNA in the 'fines' fraction compared to the sand and groundwater. Before the field-scale acetate addition, a Geobacter-like group primarily synthesized {sup 13}C-DNA in the groundwater phase, an alpha Proteobacterium primarily grew on the fines/sands, and an Acinetobacter sp. and Decholoromonas-like OTU utilized much of the {sup 13}C acetate in both groundwater and particle-associated phases. At the termination of the field-scale acetate addition, the Geobacter-like species was active on the solid phases rather than the groundwater, while the other bacterial groups had very reduced newly synthesized DNA signal. These findings will help to delineate the acetate utilization patterns of bacteria in the field and can lead to improved methods for stimulating distinct microbial populations in situ.

Kerkhof, L.; Williams, K.H.; Long, P.E.; McGuinness, L.

2011-02-21

180

Phase preference by active, acetate-utilizing bacteria at the rifle, CO integrated field research challenge site.  

PubMed

Previous experiments at the Rifle, Colorado Integrated Field Research Challenge (IFRC) site demonstrated that field-scale addition of acetate to groundwater reduced the ambient soluble uranium concentration. In this report, sediment samples collected before and after acetate field addition were used to assess the active microbes via (13)C acetate stable isotope probing on 3 phases [coarse sand, fines (8-approximately 150 ?m), groundwater (0.2-8 ?m)] over a 24-day time frame. TRFLP results generally indicated a stronger signal in (13)C-DNA in the "fines" fraction compared to the sand and groundwater. Before the field-scale acetate addition, a Geobacter-like group primarily synthesized (13)C-DNA in the groundwater phase, an alpha Proteobacterium primarily grew on the fines/sands, and an Acinetobacter sp. and Decholoromonas-like OTU utilized much of the (13)C acetate in both groundwater and particle-associated phases. At the termination of the field-scale acetate addition, the Geobacter-like species was active on the solid phases rather than the groundwater, while the other bacterial groups had very reduced newly synthesized DNA signal. These findings will help to delineate the acetate utilization patterns of bacteria in the field and can lead to improved methods for stimulating distinct microbial populations in situ. PMID:21226528

Kerkhof, Lee J; Williams, Ken H; Long, Philip E; McGuinness, Lora R

2011-01-12

181

Phase and reaction equilibria of the acetic acid-isopropanol-isopropyl acetate-water system at 760 mmHg  

Microsoft Academic Search

An energy-saving process, the so-called reactive distillation process, is attracting more and more attention in the chemical industry. This process is based on the simultaneous implementation of chemical reaction and phase equilibria in a process unit. The esterification of acetic acid and isopropyl alcohol is one of the processes that use this technology. In order to understand the thermodynamic behavior

Liang-sun Lee; Ming-zhong Kuo

1996-01-01

182

Phenyl Acetate Preparation from Phenol and Acetic Acid: Reassessment of a Common Textbook Misconception.  

ERIC Educational Resources Information Center

|Reassesses a common textbook misconception that "...phenols cannot be esterified directly." Results of experiments are discussed and data tables provided of an effective method for the direct preparation of phenyl acetate. (CS)|

Hocking, M. B.

1980-01-01

183

Stress responses in lactic acid bacteria.  

PubMed

Lactic acid bacteria (LAB) constitute a heterogeneous group of bacteria that are traditionally used to produce fermented foods. The industrialization of food bio-transformations increased the economical importance of LAB, as they play a crucial role in the development of the organoleptique and hygienic quality of fermented products. Therefore, the reliability of starter strains in terms of quality and functional properties (important for the development of aroma and texture), but also in terms of growth performance and robustness has become essential. These strains should resist to adverse conditions encountered in industrial processes, for example during starter handling and storage (freeze-drying, freezing or spray-drying). The development of new applications such as life vaccines and probiotic foods reinforces the need for robust LAB since they may have to survive in the digestive tract, resist the intestinal flora, maybe colonize the digestive or uro-genital mucosa and express specific functions under conditions that are unfavorable to growth (for example, during stationary phase or storage). Also in nature, the ability to quickly respond to stress is essential for survival and it is now well established that LAB, like other bacteria, evolved defense mechanisms against stress that allow them to withstand harsh conditions and sudden environmental changes. While genes implicated in stress responses are numerous, in LAB the levels of characterization of their actual role and regulation differ widely between species. The functional conservation of several stress proteins (for example, HS proteins, Csp, etc) and of some of their regulators (for example, HrcA, CtsR) renders even more striking the differences that exist between LAB and the classical model micro-organisms. Among the differences observed between LAB species and B. subtilis, one of the most striking is the absence of a sigma B orthologue in L. lactis ssp. lactis as well as in at least two streptococci and probably E. faecalis. The overview of LAB stress responses also reveals common aspects of stress responses. As in other bacteria, adaptive responses appear to be a usual mode of stress protection in LAB. However, the cross-protection to other stress often induced by the expression of a given adaptive response, appears to vary between species. This observation suggests that the molecular bases of adaptive responses are, at least in part, species (or even subspecies) specific. A better understanding of the mechanisms of stress resistance should allow to understand the bases of the adaptive responses and cross protection, and to rationalize their exploitation to prepare LAB to industrial processes. Moreover, the identification of crucial stress related genes will reveal targets i) for specific manipulation (to promote or limit growth), ii) to develop tools to screen for tolerant or sensitive strains and iii) to evaluate the fitness and level of adaptation of a culture. In this context, future genome and transcriptome analyses will undoubtedly complement the proteome and genetic information available today, and shed a new light on the perception of, and the response to, stress by lactic acid bacteria. PMID:12369188

van de Guchte, Maarten; Serror, Pascale; Chervaux, Christian; Smokvina, Tamara; Ehrlich, Stanislav D; Maguin, Emmanuelle

2002-08-01

184

Indole-3-acetic acid improves Escherichia coli's defences to stress.  

PubMed

Indole-3-acetic acid (IAA) is a ubiquitous molecule playing regulatory roles in many living organisms. To elucidate the physiological changes induced by IAA treatment, we used Escherichia coli K-12 as a model system. By microarray analysis we found that 16 genes showed an altered expression level in IAA-treated cells. One-third of these genes encode cell envelope components, or proteins involved in bacterial adaptation to unfavourable environmental conditions. We thus investigated the effect of IAA treatment on some of the structural components of the envelope that may be involved in cellular response to stresses. This showed that IAA-treated cells had increased the production of trehalose, lipopolysaccharide (LPS), exopolysaccharide (EPS) and biofilm. We demonstrated further that IAA triggers an increased tolerance to several stress conditions (heat and cold shock, UV-irradiation, osmotic and acid shock and oxidative stress) and different toxic compounds (antibiotics, detergents and dyes) and this correlates with higher levels of the heat shock protein DnaK. We suggest that IAA triggers an increased level of alert and protection against external adverse conditions by coordinately enhancing different cellular defence systems. PMID:16555073

Bianco, C; Imperlini, E; Calogero, R; Senatore, B; Amoresano, A; Carpentieri, A; Pucci, P; Defez, R

2006-03-23

185

Genome-wide identification of Saccharomyces cerevisiae genes required for tolerance to acetic acid  

PubMed Central

Background Acetic acid is a byproduct of Saccharomyces cerevisiae alcoholic fermentation. Together with high concentrations of ethanol and other toxic metabolites, acetic acid may contribute to fermentation arrest and reduced ethanol productivity. This weak acid is also a present in lignocellulosic hydrolysates, a highly interesting non-feedstock substrate in industrial biotechnology. Therefore, the better understanding of the molecular mechanisms underlying S. cerevisiae tolerance to acetic acid is essential for the rational selection of optimal fermentation conditions and the engineering of more robust industrial strains to be used in processes in which yeast is explored as cell factory. Results The yeast genes conferring protection against acetic acid were identified in this study at a genome-wide scale, based on the screening of the EUROSCARF haploid mutant collection for susceptibility phenotypes to this weak acid (concentrations in the range 70-110 mM, at pH 4.5). Approximately 650 determinants of tolerance to acetic acid were identified. Clustering of these acetic acid-resistance genes based on their biological function indicated an enrichment of genes involved in transcription, internal pH homeostasis, carbohydrate metabolism, cell wall assembly, biogenesis of mitochondria, ribosome and vacuole, and in the sensing, signalling and uptake of various nutrients in particular iron, potassium, glucose and amino acids. A correlation between increased resistance to acetic acid and the level of potassium in the growth medium was found. The activation of the Snf1p signalling pathway, involved in yeast response to glucose starvation, is demonstrated to occur in response to acetic acid stress but no evidence was obtained supporting the acetic acid-induced inhibition of glucose uptake. Conclusions Approximately 490 of the 650 determinants of tolerance to acetic acid identified in this work are implicated, for the first time, in tolerance to this weak acid. These are novel candidate genes for genetic engineering to obtain more robust yeast strains against acetic acid toxicity. Among these genes there are number of transcription factors that are documented regulators of a large percentage of the genes found to exert protection against acetic acid thus being considered interesting targets for subsequent genetic engineering. The increase of potassium concentration in the growth medium was found to improve the expression of maximal tolerance to acetic acid, consistent with the idea that the adequate manipulation of nutrient concentration of industrial growth medium can be an interesting strategy to surpass the deleterious effects of this weak acid in yeast cells.

2010-01-01

186

Kinetics of growth of Lactobacillus plantarum with glucose, organic acids (malate, citrate, acetate) and ethanol  

Microsoft Academic Search

L. plantarum was grown on glucose and organic acids, i.e. malate, citrate, and acetate, frequently jointly encountered in wine and cider fermentation. The effect on fermentation patterns of different mixtures of acids as well as ethanol was studied. Specific growth rates and apparent biomass yields on glucose increased when adding citrate or malate. Acetate and ethanol were not consummed by

Christian Kennes; María C. Veiga; Henry Naveau; Edmond J. Nyns

1995-01-01

187

Delignification of Bagasse with Acetic Acid and Ozone. II. Ozone Stage  

Microsoft Academic Search

Ozone gas was applied as second stage in delignification of bagasse pulp obtained with acetic acid. The kappa number was reduced from 44 to 10 with 3% ozone (based on dry pulp). Because bagasse was pulped with an aqueous solution of acetic acid (80% volume), selectivity of the ozone stage was favored and does not necessary acidulate pulp, which had

H. Contreras Q; Z. A. Nagieb; R. SanjuáN D

1997-01-01

188

Effects of acetic acid on the rice gelatinization and pasting properties of rice starch during cooking  

Microsoft Academic Search

The mechanism of the textural changes such as increase in stickiness of rice cooked with acetic acid was studied focusing on the gelatinization and rheological properties of both rice starch and rice flour. The results of swelling power and solubility of rice starch indicated that acetic acid promoted water absorption of amylopectin in rice starch. It was shown by DSC

Kyoko Ohishi; Midori Kasai; Atsuko Shimada; Keiko Hatae

2007-01-01

189

Microbiological preservation of cucumbers for bulk storage by the use of acetic acid and food preservatives  

Technology Transfer Automated Retrieval System (TEKTRAN)

Microbial growth did not occur when cucumbers were preserved without a thermal process by storage in solutions containing acetic acid, sodium benzoate, and calcium chloride to maintain tissue firmness. The concentrations of acetic acid and sodium benzoate required to assure preservation were low en...

190

Energetic and economic evaluation of the production of acetic acid via ethane oxidation  

Microsoft Academic Search

Acetic acid production via the selective oxidation of ethane was studied. The feed composition and mode of dilution was taken as a major parameter in reactor and process simulation. The concentration of water (as a component improving acetic acid selectivity) in the reaction feed was varied. Heat and mass balances were predicted. Finally, the ethane direct oxidation process was compared

Q. Smejkal; D. Linke; M. Baerns

2005-01-01

191

Impact of trace element addition on degradation efficiency of volatile fatty acids, oleic acid and phenyl acetate and on microbial populations in a biogas digester.  

PubMed

The effect of trace element addition on anaerobic digestion of food industry- and household waste was studied using two semi-continuous lab-scale reactors, one (R30+) was supplied with Fe, Co and Ni, while the other (R30) acted as a control. Tracer analysis illustrated that methane production from acetate proceeded through syntrophic acetate oxidation (SAO) in both digesters. The effect of the trace elements was also evaluated in batch assays to determine the capacity of the microorganisms of the two digesters to degrade acetate, phenyl acetate, oleic acid or propionate, butyrate and valerate provided as a cocktail. The trace elements addition improved the performance of the process giving higher methane yields during start-up and early operation and lower levels of mainly acetate and propionate in the R30+ reactor. The batch assay showed that material from R30+ gave effects on methane production from all substrates tested. Phenyl acetate was observed to inhibit methane formation in the R30 but not in the R30+ assay. A real-time PCR analysis targeting methanogens on the order level as well as three SAO bacteria showed an increase in Methanosarcinales in the R30+ reactor over time, even though SAO continuously was the dominating pathway for methane production. Possibly, this increase explains the low VFA-levels and higher degradation rates observed in the R30+ batch incubations. These results show that the added trace elements affected the ability of the microflora to degrade VFAs as well as oleic acid and phenyl acetate in a community, where acetate utilization is dominated by SAO. PMID:22683024

Karlsson, Anna; Einarsson, Peter; Schnürer, Anna; Sundberg, Carina; Ejlertsson, Jörgen; Svensson, Bo H

2012-06-09

192

Kinetics and mechanism of acetic acid pulping of detannined Pinus pinaster bark  

Microsoft Academic Search

The observed kinetics of Pinus pinaster bark with acetic acid after alkali treatment, with or without intervening acid prehydrolysis, are satisfactorily explained by a model involving both solubilization and condensation reactions.

G. Vázquez; G. Antorrena; J. González

1994-01-01

193

40 CFR 721.10211 - Octadecanoic acid, reaction products with diethylenetriamine and urea, acetates.  

Code of Federal Regulations, 2013 CFR

...New Uses for Specific Chemical Substances § 721.10211 Octadecanoic acid, reaction products with diethylenetriamine...acetates. (a) Chemical substance and significant...reporting . (1) The chemical substance identified as octadecanoic acid, reaction products with...

2013-07-01

194

Acetate Binding of Spinach Chloroplasts as a Facet of Fatty Acid Synthesis  

PubMed Central

A particulate fraction of spinach chloroplasts is the major site of binding when either acetate or acetyl-CoA is used as substrate. The acetate is linked covalently, and the binding is inhibited by reagents which react with sulfhydryl groups. The amount of acetate bound is lowered by both citrate and oxaloacetate; however, the binding is not reversed by oxaloacetate. Reversal of binding is also not brought about by the addition of unlabeled acetyl-CoA. If cofactors for fatty acid synthesis and cold acetyl-CoA are added, the binding of labeled acetate is reversed. Acyl carrier protein from E. coli increases the binding of labeled acetate.

Devor, K. A.; Mudd, J. B.

1968-01-01

195

Glycerol metabolism and bitterness producing lactic acid bacteria in cidermaking.  

PubMed

Several lactic acid bacteria were isolated from bitter tasting ciders in which glycerol was partially removed. The degradation of glycerol via glycerol dehydratase pathway was found in 22 out of 67 isolates. The confirmation of glycerol degradation by this pathway was twofold: showing their glycerol dehydratase activity and detecting the presence of the corresponding gene by a PCR method. 1,3-propanediol (1,3-PDL) and 3-hydroxypropionic acid (3-HP) were the metabolic end-products of glycerol utilization, and the accumulation of the acrolein precursor 3-hydroxypropionaldehyde (3-HPA) was also detected in most of them. The strain identification by PCR-DGGE rpoB showed that Lactobacillus collinoides was the predominant species and only 2 belonged to Lactobacillus diolivorans. Environmental conditions conducting to 3-HPA accumulation in cidermaking were studied by varying the fructose concentration, pH and incubation temperature in L. collinoides 17. This strain failed to grow with glycerol as sole carbon source and the addition of fructose enhanced both growth and glycerol degradation. Regarding end-products of glycerol metabolism, 1,3-PDL was always the main end-product in all environmental conditions assayed, the only exception being the culture with 5.55 mM fructose, where equimolar amounts of 1,3-PDL and 3-HP were found. The 3-HPA was transitorily accumulated in the culture medium under almost all culture conditions, the degradation rate being notably slower at 15 degrees C. However, no disappearance of 3-HPA was found at pH 3.6, a usual value in cider making. After sugar exhaustion, L. collinoides 17 oxidated lactic acid and/or mannitol to obtain energy and these oxidations were accompanied by the removal of the toxic 3-HPA increasing the 1,3-PDL, 3-HP and acetic acid contents. PMID:18180066

Garai-Ibabe, G; Ibarburu, I; Berregi, I; Claisse, O; Lonvaud-Funel, A; Irastorza, A; Dueñas, M T

2007-11-12

196

Ethenzamide-gentisic acid-acetic acid (2/1/1)  

PubMed Central

In the title co-crystal solvate, 2-ethoxy­benzamide–2,5-dihydroxy­benzoic acid–ethanoic acid (2/1/1), 2C9H11NO2·C7H6O4·C2H4O2, two nonsteroidal anti-inflammatory drugs, ethenzamide (systematic name: 2-ethoxy­benzamide) and gentisic acid (systematic name: 2,5-dihydroxy­benzoic acid), together with acetic acid (systematic name: ethanoic acid) form a four-component mol­ecular assembly held together by N—H?O and O—H?O hydrogen bonds. This assembly features two symmetry-independent mol­ecules of ethenzamide, forming supra­molecular acid–amide heterosynthons with gentisic acid and acetic acid. These heterosynthons involve quite strong O—H?O [O?O = 2.5446?(15) and 2.5327?(15)?Å] and less strong N—H?O [N?O = 2.9550?(17) and 2.9542?(17)?Å] hydrogen bonds. The overall crystal packing features several C—H?O and ?–? stacking inter­actions [centroid–centroid distance = 3.7792?(11)?Å].

Aitipamula, Srinivasulu; Chow, Pui Shan; Tan, Reginald B.H.

2010-01-01

197

Ethenzamide-gentisic acid-acetic acid (2/1/1).  

PubMed

In the title co-crystal solvate, 2-ethoxy-benzamide-2,5-dihydroxy-benzoic acid-ethanoic acid (2/1/1), 2C(9)H(11)NO(2)·C(7)H(6)O(4)·C(2)H(4)O(2), two nonsteroidal anti-inflammatory drugs, ethenzamide (systematic name: 2-ethoxy-benzamide) and gentisic acid (systematic name: 2,5-dihydroxy-benzoic acid), together with acetic acid (systematic name: ethanoic acid) form a four-component mol-ecular assembly held together by N-H?O and O-H?O hydrogen bonds. This assembly features two symmetry-independent mol-ecules of ethenzamide, forming supra-molecular acid-amide heterosynthons with gentisic acid and acetic acid. These heterosynthons involve quite strong O-H?O [O?O = 2.5446?(15) and 2.5327?(15)?Å] and less strong N-H?O [N?O = 2.9550?(17) and 2.9542?(17)?Å] hydrogen bonds. The overall crystal packing features several C-H?O and ?-? stacking inter-actions [centroid-centroid distance = 3.7792?(11)?Å]. PMID:21579106

Aitipamula, Srinivasulu; Chow, Pui Shan; Tan, Reginald B H

2010-04-10

198

Lactic acid bacteria and the human gastrointestinal tract  

Microsoft Academic Search

Objective: This review summarises the effects of lactic acid bacteria on lactose malabsorption, bacterial\\/viral or antibiotic associated diarrhoea, and describes the impact of lactic acid bacteria on cancer and the fermentative products in the colon.Results: Eight studies (including 78 patients) demonstrated that lactase deficient subjects absorbed lactose in yogurt better than lactose in milk, while two studies (25 patients) did

H Hove; H Nørgaard; P Brøbech Mortensen

1999-01-01

199

Kozakia baliensis gen. nov., sp. nov., a novel acetic acid bacterium in the alpha-proteobacteria.  

PubMed

Four bacterial strains were isolated from palm brown sugar and ragi collected in Bali and Yogyakarta, Indonesia, by an enrichment culture approach for acetic acid bacteria. Phylogenetic analysis based on 16S rRNA gene sequences showed that the four isolates constituted a cluster separate from the genera Acetobacter, Gluconobacter, Acidomonas, Gluconacetobacter and Asaia with a high bootstrap value in a phylogenetic tree. The isolates had high values of DNA-DNA similarity (78-100%) between one another and low values of the similarity (7-25%) to the type strains of Acetobacter aceti, Gluconobacter oxydans, Gluconacetobacter liquefaciens and Asaia bogorensis. The DNA base composition of the isolates ranged from 56.8 to 57.2 mol% G+C with a range of 0-4 mol%. The major quinone was Q-10. The isolates oxidized acetate and lactate to carbon dioxide and water, but the activity was weak, as with strains of Asaia bogorensis. The isolates differed from Asaia bogorensis strains in phenotypic characteristics. The name Kozakia baliensis gen. nov., sp. nov., is proposed for the four isolates. Strain Yo-3T (= NRIC 0488T = JCM 11301T = IFO 16664T = DSM 14400T) was isolated from palm brown sugar collected in Bali, Indonesia, and was designated as the type strain. PMID:12054243

Lisdiyanti, Puspita; Kawasaki, Hiroko; Widyastuti, Yantyati; Saono, Susono; Seki, Tatsuji; Yamada, Yuzo; Uchimura, Tai; Komagata, Kazuo

2002-05-01

200

Determination of halogenated acetic acids in chlorinated sea water and drinking water produced offshore  

Microsoft Academic Search

The formation of halogenated acetic acids in laboratory chlorinated sea water as well as chlorinated sea water and drinking water produced on an oil-installation offshore was investigated. Analyses were performed using solvent extraction and capillary gas chromatography with electron capture detection and mass spectrometry. Dichloroacetic acid, trichloroacetic acid, dibromoacetic acid and tribromoacetic acid were found in the water samples, with

Nina K. Kristiansen; Kjersti T. Aune; May Frøshaug; Georg Becher; Elsa Lundanes

1996-01-01

201

Metabolic regulation of the plant hormone indole-3-acetic acid  

SciTech Connect

The phytohormone indole-3-acetic acid (IAA, auxin) is important for many aspects of plant growth, development and responses to the environment yet the routes to is biosynthesis and mechanisms for regulation of IAA levels remain important research questions. A critical issue concerning the biosynthesis if IAA in plants is that redundant pathways for IAA biosynthesis exist in plants. We showed that these redundant pathways and their relative contribution to net IAA production are under both developmental and environmental control. We worked on three fundamental problems related to how plants get their IAA: 1) An in vitro biochemical approach was used to define the tryptophan dependent pathway to IAA using maize endosperm, where relatively large amounts of IAA are produced over a short developmental period. Both a stable isotope dilution and a protein MS approach were used to identify intermediates and enzymes in the reactions. 2) We developed an in vitro system for analysis of tryptophan-independent IAA biosynthesis in maize seedlings and we used a metabolite profiling approach to isolate intermediates in this reaction. 3) Arabidopsis contains a small family of genes that encode potential indolepyruvate decarboxylase enzymes. We cloned these genes and studied plants that are mutant in these genes and that over-express each member in the family in terms of the level and route of IAA biosynthesis. Together, these allowed further development of a comprehensive picture of the pathways and regulatory components that are involved in IAA homeostasis in higher plants.

Jerry D. Cohen

2009-11-01

202

Ameyamaea chiangmaiensis gen. nov., sp. nov., an acetic acid bacterium in the alpha-Proteobacteria.  

PubMed

Two isolates, AC04(T) and AC05, were isolated from the flowers of red ginger collected in Chiang Mai, Thailand. In phylogenetic trees based on 16S rRNA gene sequences, the two isolates were included within a lineage comprised of the genera Acidomonas, Gluconacetobacter, Asaia, Kozakia, Swaminathania, Neoasaia, Granulibacter, and Tanticharoenia, and they formed an independent cluster along with the type strain of Tanticharoenia sakaeratensis. The calculated pair-wise sequence similarities of isolate AC04(T) were 97.8-92.5% to the type strains of the type species of the 11 genera of acetic acid bacteria. The DNA base composition was 66.0-66.1 mol % G+C with a range of 0.1 mol %. A single-stranded, labeled DNA from isolate AC04(T) presented levels of DNA-DNA hybridization of 100, 85, 4, and 3% respectively to DNAs from isolates AC04(T) and AC05 and the type strains of Tanticharoenia sakaeratensis and Gluconacetobacter liquefaciens. The two isolates were unique morphologically in polar flagellation and physiologically in intense acetate oxidation to carbon dioxide and water and weak lactate oxidation. The intensity in acetate oxidation almost equaled that of the type strain of Acetobacter aceti. The two isolates had Q-10. Isolate AC04(T) was discriminated from the type strains of the type species of the 11 genera by 16S rRNA gene restriction analysis using restriction endonucleases TaqI and Hin6I. The unique phylogenetic, genetic, morphological, physiological, and biochemical characteristics obtained indicate that the two isolates can be classified into a separate genus, and Ameyamaea chiangmaiensis gen. nov., sp. nov. is proposed. The type strain is isolate AC04(T) (=BCC 15744(T), =NBRC 103196(T)), which has a DNA G+C content of 66.0 mol %. PMID:19809199

Yukphan, Pattaraporn; Malimas, Taweesak; Muramatsu, Yuki; Takahashi, Mai; Kaneyasu, Mika; Potacharoen, Wanchern; Tanasupawat, Somboon; Nakagawa, Yasuyoshi; Hamana, Koei; Tahara, Yasutaka; Suzuki, Ken-ichiro; Tanticharoen, Morakot; Yamada, Yuzo

2009-10-07

203

A potential plasmid-curing agent, 8-epidiosbulbin E acetate, from Dioscorea bulbifera L. against multidrug-resistant bacteria  

Microsoft Academic Search

Bioassay-guided fractionation of an aqueous methanolic extract of Dioscorea bulbifera L. bulbs was performed using organic solvents. A novel plasmid-curing compound was identified as 8-epidiosbulbin E acetate (EEA) (norditerpene) on the basis of modern spectroscopic analysis and X-ray crystallography. EEA exhibited broad-spectrum plasmid-curing activity against multidrug-resistant (MDR) bacteria, including vancomycin-resistant enterococci. EEA cured antibiotic resistance plasmids (R-plasmids) from clinical isolates

Varsha Shriram; Sheetal Jahagirdar; C. Latha; Vinay Kumar; Vedavati Puranik; Supada Rojatkar; Prashant K. Dhakephalkar; M. G. Shitole

2008-01-01

204

Increases in jasmonic acid caused by indole-3-acetic acid and auxin herbicides in cleavers ( Galium aparine)  

Microsoft Academic Search

The effects of indole-3-acetic acid and auxin herbicides on endogenous jasmonic acid (JA) concentrations were studied in relation to changes in ethylene and abscisic acid (ABA) levels in cleavers (Galium aparine). When plants were root-treated with increasing concentrations of indole-3-acetic acid (IAA), ethylene biosynthesis was stimulated in response to the accumulation of endogenous IAA in the shoot tissue. Within 25h

Klaus Grossmann; Cindy Rosenthal; Jacek Kwiatkowski

2004-01-01

205

Diffusion and Sorption of Organic Liquids Through Polymer Membranes. VII. Elastomers Versus Acetic Acid and Dichloroacetic Acid  

Microsoft Academic Search

Diffusion coefficients of five elastomer membranes, viz., nitrile butadiene rubber, styrene–butadiene rubber, ethylene–propylene–diene terpolymer, neoprene, and natural rubber with acetic acid and dichloroacetic acids have been obtained from gravimetric sorption experiments. For acetic acid, the diffusion seems to follow the expected Fickian mechanism whereas for dichloroacetic acid, the diffusion appears to follow the non-Fickian mechanism for natural rubber and nitrile

T. M. Aminabhavi; R. S. Khinnavar; R. H. Balundgi

1994-01-01

206

Oxidation of acetate through reactions of the citric acid cycle by Geobacter sulfurreducens in pure culture and in syntrophic coculture  

Microsoft Academic Search

Geobacter sulfurreducens strain PCA oxidized acetate to CO2 via citric acid cycle reactions during growth with acetate plus fumarate in pure culture, and with acetate plus nitrate in coculture with Wolinella succinogenes. Acetate was activated by succinyl-CoA:acetate CoA-transferase and also via acetate kinase plus phosphotransacetylase. Citrate was formed by citrate synthase. Soluble isocitrate and malate dehydrogenases reduced NADP+ and NAD+,

Alexander S. Galushko; Bernhard Schink

2000-01-01

207

Bacterial strains from human feces that reduce CO2 to acetic acid.  

PubMed Central

We used dilutions of fecal suspensions from a human volunteer to enrich cultures for bacteria that reduce CO2 to acetate in the colon. The soluble enrichment substrates used were glucose, methanol, formate, and vanillate, which were used with a gas phase that contained 80% N2 and 20% CO2. The gaseous enrichment substrates used were 80% H2-20% CO2 and 50% CO-50% CO2. We isolated three different strains that produced acetate from CO2. One strain produced acetate from methanol, vanillate, H2-CO2, glucose, and other sugars. The other two strains did not form acetate from methanol or vanillate. Both of the latter strains formed acetate from glucose and other sugars, but only one of these strains formed acetate from H2-CO2. Both of these strains cometabolized formate. However, none of the enrichment cultures or pure cultures used CO or formate as a substrate for growth. The two strains that produced acetate from H2 and CO2 grew slowly when the gases alone were used as substrates, but they rapidly cometabolized H2 and CO2 when they were grown with organic substrates. The ability of all of the strains to produce acetate from CO2 and/or other one-carbon precursors was verified by determining the radioactivity of the methyl and carboxyl groups of the acetate formed after growth with 14CO2 or other radioactively labeled one-carbon precursors.

Wolin, M J; Miller, T L

1993-01-01

208

Delignification of Eucalyptus globulus saplings in two organosolv systems (formic and acetic acid)  

Microsoft Academic Search

Organosolv delignification of 2–3 years old Eucalyptus globulus with formic or acetic acid produced bleachable grade pulps with kappa number values of 20–35. Pulp yields for the acetic acid treatment (45–55%) were higher than for formic acid (32–46%) although also they showed the greater kappa number.Delignification was modelized by means of the accomplishment of respective factorial designs of experiments. Data

Pablo Ligero; Juan José Villaverde; Alberto de Vega; Manuel Bao

2008-01-01

209

Severe renal function impairment in adult patients acutely poisoned with concentrated acetic acid.  

PubMed

Acetic acid is a widely used organic acid with corrosive properties that depend on its concentration. If acetic acid is ingested in concentrations above 30 % it may severely damage the upper gastrointestinal tract and cause intravascular haemolysis, which can result in severe kidney and liver disorders and disseminated intravascular coagulation. In this retrospective study, we analysed acetic acid ingestion data collected at the University Clinic for Toxicology of Skopje, Macedonia from 1 January 2002 to 31 December 2011. The analysis included systemic complications, kidney damage, and the outcomes in particular. Over the ten years, 84 patients were reported at the Clinic to have ingested highly concentrated acetic acid. Twenty-eight developed kidney disorders, while the remaining 56 had no complications. Fatal outcome was reported for 11 patients, seven of whom had systemic complications and four severe gastrointestinal complications. PMID:23585201

Chibishev, Andon; Sikole, Aleksandar; Pereska, Zanina; Chibisheva, Vesna; Simonovska, Natasha; Orovchanec, Nikola

2013-03-01

210

Isolation of cellulose from rice straw and its conversion into cellulose acetate catalyzed by phosphotungstic acid.  

PubMed

Cellulose was isolated from rice straw by pretreatment with dilute alkaline and acid solutions successively, and it was further transferred into cellulose acetate in the presence of acetic anhydride and phosphotungstic acid (H3PW12O40·6H2O). The removal of hemicellulose and lignin was affected by the concentration of KOH and the immersion time in acetic acid solution, and 83wt.% content of cellulose in the treated rice straw was obtained after pretreatment with 4% KOH and immersion in acetic acid for 5h. Phosphotungstic acid was found to be an effective catalyst for the acetylation of the cellulose derived from rice straw. The degree of substitution (DS) values revealed a significant effect for the solubility of cellulose acetate, and the acetone-soluble cellulose acetate with DS values around 2.2 can be obtained by changing the amount of phosphotungstic acid and the time of acetylation. Both the structure of cellulose separated from rice straw and cellulose acetate were confirmed by FTIR and XRD. PMID:23544511

Fan, Guozhi; Wang, Min; Liao, Chongjing; Fang, Tao; Li, Jianfen; Zhou, Ronghui

2013-02-01

211

Pervaporation of acetic acid\\/water mixtures through carbon molecular sieve-filled PDMS membranes  

Microsoft Academic Search

The pervaporation process for acetic\\/water has been investigated with carbon molecular sieve (CMS)-filled polydimethylsiloxane (PDMS) membranes. The effects of feed temperature, feed acetic acid concentration and CMS content on the performance of the membranes have been studied. It is found that the addition of CMS can improve pervaporation behavior of PDMS membranes to some extent and greatly increases the strength

Lei Li; Zeyi Xiao; Zhibing Zhang; Shujuan Tan

2004-01-01

212

Effect of Acetic Acid Supplementation on Egg Quality Characteristics of Commercial Laying Hens during Hot Season  

Microsoft Academic Search

This study was conducted to determine the effects of acetic acid supplement at four levels (control, 200, 400 and 600-ppm in drinking water) on egg production and quality in commercial Brown Leghorn reared birds during the hot season (32°C). One hundred and sixty 30 week-old laying birds were randomly divided into 4 groups and subjected to four levels of acetic

I. T. Kadim; W. Al-Marzooqi; O. Mahgoub; A. Al-Jabri; S. K. Al-Waheebi

2008-01-01

213

Uptake kinetics of acetic acid and acetone on ice surfaces at 190 - 223 K  

Microsoft Academic Search

Heterogeneous reactions of oxygenated organics may influence the oxidation capacity of the atmosphere with a direct impact on the tropospheric ozone budget. Direct trace gas measurements in the upper troposphere have revealed a high mixing ratio acetic acid (up to 1.9 ppb) and acetone (up to 3 ppb). In the present study we have examined the heterogeneous interactions of acetic

A. Terziyski; P. Behr; U. Scharfenort; K. Demiral; R. Zellner

2003-01-01

214

Enzymological and Genetic Studies of One-Carbon Reactions in the Pathway of Acetate Utilization by Methanogenic Bacteria. Annual Report February 1986-December 1986.  

National Technical Information Service (NTIS)

The project focused on determining the biochemical pathway and mechanisms of acetate conversion to methane in methanogenic bacteria. A corrinoid cofactor was discovered in the carbon monoxide dehydrogenase complex previously shown to be involved in the pa...

J. G. Ferry

1987-01-01

215

Main and interaction effects of acetic acid, furfural, and p-hydroxybenzoic acid on growth and ethanol productivity of yeasts  

Microsoft Academic Search

The influence of the factors acetic acid, furfural, and p-hydroxybenzoic acid on the ethanol yield (Y{sub EtOH}) of Saccharomyces cerevisiae, bakers` yeast, S. cerevisiae ATCC 96581, and Candida shehatae NJ 23 was investigated using a 2³-full factorial design with 3 centerpoints. The results indicated that acetic acid inhibited the fermentation by C. shehatae NJ 23 markedly more than by bakers`

Eva Palmqvist; Halfdan Grage; Nina Q. Meinander; B. Hahn-Haegerdal

1999-01-01

216

Production of Value-added Products by Lactic Acid Bacteria  

Technology Transfer Automated Retrieval System (TEKTRAN)

Lactic acid bacteria (LAB) are a group of facultative anaerobic, catalase negative, nonmotile and nonsporeforming–Gram positive bacteria. Most LAB utilize high energy C sources including monomer sugars to produce energy to maintain cellular structure and function. This anaerobic fermentation proce...

217

Diversity of lactic acid bacteria of the bioethanol process  

Microsoft Academic Search

BACKGROUND: Bacteria may compete with yeast for nutrients during bioethanol production process, potentially causing economic losses. This is the first study aiming at the quantification and identification of Lactic Acid Bacteria (LAB) present in the bioethanol industrial processes in different distilleries of Brazil. RESULTS: A total of 489 LAB isolates were obtained from four distilleries in 2007 and 2008. The

Brigida TL Lucena; Billy M dos Santos; João LS Moreira; Ana Paula B Moreira; Alvaro C Nunes; Vasco Azevedo; Anderson Miyoshi; Fabiano L Thompson; Marcos de Morais

2010-01-01

218

Lactic acid bacteria - a new tool for medicine and pharmacology?  

Microsoft Academic Search

Lactic acid bacteria are a heterogeneous and highly diverse group of microorganisms classified with the status GRAS (Generally Regarded As Safe), meaning that they do not cause illness in humans. They play and important economic role - having been used in the basic production of foods and animal feeds for several millennia. Nowadays such bacteria are being harnessed ever more

JACEK BARDOWSKI

219

Comparative analysis of CRISPR loci in lactic acid bacteria genomes  

Microsoft Academic Search

Clustered regularly interspaced short palindromic repeats (CRISPR) are hypervariable loci widely distributed in bacteria and archaea, that provide acquired immunity against foreign genetic elements. Here, we investigate the occurrence of CRISPR loci in the genomes of lactic acid bacteria (LAB), including members of the Firmicutes and Actinobacteria phyla. A total of 102 complete and draft genomes across 11 genera were

Philippe Horvath; Anne-Claire Coûté-Monvoisin; Dennis A. Romero; Patrick Boyaval; Christophe Fremaux; Rodolphe Barrangou

2009-01-01

220

Asaia siamensis sp. nov., an acetic acid bacterium in the alpha-proteobacteria.  

PubMed

Five bacterial strains were isolated from tropical flowers collected in Thailand and Indonesia by the enrichment culture approach for acetic acid bacteria. Phylogenetic analysis based on 16S rRNA gene sequences showed that the isolates were located within the cluster of the genus Asaia. The isolates constituted a group separate from Asaia bogorensis on the basis of DNA relatedness values. Their DNA G+C contents were 58.6-59.7 mol%, with a range of 1.1 mol%, which were slightly lower than that of A. bogorensis (59.3-61.0 mol%), the type species of the genus Asaia. The isolates had morphological, physiological and biochemical characteristics similar to A. bogorensis strains, but the isolates did not produce acid from dulcitol. On the basis of the results obtained, the name Asaia siamensis sp. nov. is proposed for these isolates. Strain S60-1T, isolated from a flower of crown flower (dok rak, Calotropis gigantea) collected in Bangkok, Thailand, was designated the type strain ( = NRIC 0323T = JCM 10715T = IFO 16457T). PMID:11321102

Katsura, K; Kawasaki, H; Potacharoen, W; Saono, S; Seki, T; Yamada, Y; Uchimura, T; Komagata, K

2001-03-01

221

Identification of Lactic Acid Bacteria in Michigan Cherry Wines  

Microsoft Academic Search

Many factors contribute to the final flavor of wine. One factor is malolactic fermentation, during which lactic acid bacteria (LAB) transform the harsh tasting malic acid into a more drinkable lactic acid in grape wine. The role of LAB in the production of cherry wine is completely unknown. The goal of this study is to identify the species of LAB

Emily Henk; Margaret Dietrich; Terri Weese

2008-01-01

222

Metabolic Regulation of the Plant Hormone Indole-3-Acetic Acid, (Final Report).  

National Technical Information Service (NTIS)

The phytohormone indole-3-acetic acid (IAA, auxin) is important for many aspects of plant growth, development and responses to the environment yet the routes to is biosynthesis and mechanisms for regulation of IAA levels remain important research question...

J. D. Cohen

2009-01-01

223

2-(1H-Pyrazol-4-yl)acetic acids as CRTh2 antagonists.  

PubMed

High throughput screening identified the pyrazole-4-acetic acid substructure as CRTh2 receptor antagonists. Optimisation of the compounds uncovered a tight SAR but also identified some low nanomolar inhibitors. PMID:23601708

Andrés, Miriam; Bravo, Mónica; Buil, Maria Antonia; Calbet, Marta; Castro, Jordi; Domènech, Teresa; Eichhorn, Peter; Ferrer, Manel; Gómez, Elena; Lehner, Martin D; Moreno, Imma; Roberts, Richard S; Sevilla, Sara

2013-04-02

224

Culture medium optimization for acetic acid production by a persimmon vinegar-derived bacterium.  

PubMed

A new acetic acid-producing microorganism, Acetobacter sp. RKY4, was isolated from Korean traditional persimmon vinegar, and we optimized the culture medium for acetic acid production from ethanol using the newly isolated Acetobacter sp. RKY4. The optimized culture medium for acetic acid production using this microorganism was found to be 40 g/L ethanol, 10 g/L glycerol, 10 g/L corn steep liquor, 0.5 g/L MgSO4.7H2O, and 1.0 g/L (NH4)H2PO4. Acetobacter sp. RKY4 produced 47.1 g/L of acetic acid after 48 h of fermentation in a 250 mL Erlenmeyer flask containing 50 mL of the optimized medium. PMID:15930565

Kim, Jin-Nam; Choo, Jong-Sok; Wee, Young-Jung; Yun, Jong-Sun; Ryu, Hwa-Won

2005-01-01

225

Recovery of acetic acid from dilute aqueous solutions using catalytic dehydrative esterification with ethanol.  

PubMed

We have developed a direct esterification of aqueous acetic acid with ethanol (molar ratio=1:1) catalyzed by polystyrene-supported or homogeneous sulfonic acids toward the recovery of acetic acid from wastewater in chemical plants. The equilibrium yield was significantly increased by the addition of toluene, which had a high ability to extract ethyl acetate from the aqueous phase. It was shown that low-loading and alkylated polystyrene-supported sulfonic acid efficiently accelerated the reaction. These results suggest that the construction of hydrophobic reaction environments in water was critical in improving the chemical yield. Addition of inorganic salts was also effective for the reaction under not only biphasic conditions (toluene-water) but also toluene-free conditions, because the mutual solubility of ethyl acetate and water was suppressed by the salting-out effect. Among the tested salts, CaCl(2) was found to be the most suitable for this reaction system. PMID:23290939

Yagyu, Daisuke; Ohishi, Tetsuo; Igarashi, Takeshi; Okumura, Yoshikuni; Nakajo, Tetsuo; Mori, Yuichiro; Kobayashi, Sh?

2013-01-03

226

40 CFR 180.1258 - Acetic acid; exemption from the requirement of a tolerance.  

Code of Federal Regulations, 2013 CFR

...the requirement of a tolerance. (a) An exemption from the requirement of a tolerance is established for residues of the biochemical pesticide acetic acid when used as a preservative on post-harvest agricultural commodities intended for animal...

2013-07-01

227

Three manganese oxide-rich marine sediments harbor similar communities of acetate-oxidizing manganese-reducing bacteria  

PubMed Central

Dissimilatory manganese reduction dominates anaerobic carbon oxidation in marine sediments with high manganese oxide concentrations, but the microorganisms responsible for this process are largely unknown. In this study, the acetate-utilizing manganese-reducing microbiota in geographically well-separated, manganese oxide-rich sediments from Gullmar Fjord (Sweden), Skagerrak (Norway) and Ulleung Basin (Korea) were analyzed by 16S rRNA-stable isotope probing (SIP). Manganese reduction was the prevailing terminal electron-accepting process in anoxic incubations of surface sediments, and even the addition of acetate stimulated neither iron nor sulfate reduction. The three geographically distinct sediments harbored surprisingly similar communities of acetate-utilizing manganese-reducing bacteria: 16S rRNA of members of the genera Colwellia and Arcobacter and of novel genera within the Oceanospirillaceae and Alteromonadales were detected in heavy RNA-SIP fractions from these three sediments. Most probable number (MPN) analysis yielded up to 106 acetate-utilizing manganese-reducing cells cm?3 in Gullmar Fjord sediment. A 16S rRNA gene clone library that was established from the highest MPN dilutions was dominated by sequences of Colwellia and Arcobacter species and members of the Oceanospirillaceae, supporting the obtained RNA-SIP results. In conclusion, these findings strongly suggest that (i) acetate-dependent manganese reduction in manganese oxide-rich sediments is catalyzed by members of taxa (Arcobacter, Colwellia and Oceanospirillaceae) previously not known to possess this physiological function, (ii) similar acetate-utilizing manganese reducers thrive in geographically distinct regions and (iii) the identified manganese reducers differ greatly from the extensively explored iron reducers in marine sediments.

Vandieken, Verona; Pester, Michael; Finke, Niko; Hyun, Jung-Ho; Friedrich, Michael W; Loy, Alexander; Thamdrup, Bo

2012-01-01

228

Three manganese oxide-rich marine sediments harbor similar communities of acetate-oxidizing manganese-reducing bacteria.  

PubMed

Dissimilatory manganese reduction dominates anaerobic carbon oxidation in marine sediments with high manganese oxide concentrations, but the microorganisms responsible for this process are largely unknown. In this study, the acetate-utilizing manganese-reducing microbiota in geographically well-separated, manganese oxide-rich sediments from Gullmar Fjord (Sweden), Skagerrak (Norway) and Ulleung Basin (Korea) were analyzed by 16S rRNA-stable isotope probing (SIP). Manganese reduction was the prevailing terminal electron-accepting process in anoxic incubations of surface sediments, and even the addition of acetate stimulated neither iron nor sulfate reduction. The three geographically distinct sediments harbored surprisingly similar communities of acetate-utilizing manganese-reducing bacteria: 16S rRNA of members of the genera Colwellia and Arcobacter and of novel genera within the Oceanospirillaceae and Alteromonadales were detected in heavy RNA-SIP fractions from these three sediments. Most probable number (MPN) analysis yielded up to 10(6) acetate-utilizing manganese-reducing cells cm(-3) in Gullmar Fjord sediment. A 16S rRNA gene clone library that was established from the highest MPN dilutions was dominated by sequences of Colwellia and Arcobacter species and members of the Oceanospirillaceae, supporting the obtained RNA-SIP results. In conclusion, these findings strongly suggest that (i) acetate-dependent manganese reduction in manganese oxide-rich sediments is catalyzed by members of taxa (Arcobacter, Colwellia and Oceanospirillaceae) previously not known to possess this physiological function, (ii) similar acetate-utilizing manganese reducers thrive in geographically distinct regions and (iii) the identified manganese reducers differ greatly from the extensively explored iron reducers in marine sediments. PMID:22572639

Vandieken, Verona; Pester, Michael; Finke, Niko; Hyun, Jung-Ho; Friedrich, Michael W; Loy, Alexander; Thamdrup, Bo

2012-05-10

229

Oxide-catalyzed conversion of acetic acid into acetone: an FTIR spectroscopic investigation  

Microsoft Academic Search

Adsorptive and catalytic interactions of gas phase acetic acid with surfaces of alumina, titania and ceria were observed by in situ Fourier-transform infrared (FTIR) spectroscopy on heating from room temperature up to 400°C. The results revealed that, on alumina the acid was irreversibly, non-dissociatively adsorbed in the form of hydrogen-bonded molecules, and dissociatively in the form of bidentate bound acetate

M. A. Hasan; M. I. Zaki; L. Pasupulety

2003-01-01

230

Investigation of acetic acid-catalyzed hydrothermal pretreatment on corn stover  

Microsoft Academic Search

Acetic acid (AA)-catalyzed liquid hot water (LHW) pretreatments on raw corn stover (RCS) were carried out at 195 °C at 15 min\\u000a with the acetic acid concentrations between 0 and 400 g\\/kg RCS. After pretreatment, the liquor fractions and water-insoluble\\u000a solids (WIS) were collected separately and tested in terms of the recoveries of glucan and xylan from both the liquor fractions\\u000a and the

Jian Xu; Mette Hedegaard Thomsen; Anne Belinda Thomsen

2010-01-01

231

Formic and acetic acid over the central Amazon region, Brazil 1. Dry season  

Microsoft Academic Search

We have determined the atmospheric concentrations of formic and acetic acid in the gas phase, in aerosols, and in rain during the dry season (July--August 1985) in the Amazonia region of Brazil. At ground level the average concentrations of gas phase formic and acetic acid were 1.6 +- 0.6 and 2.2 +- 1.0 ppb, respectively. The diurnal behavior of both

M. O. Andreae; R. W. Talbot; T. W. Andreae; R. C. Harriss

1988-01-01

232

Induction of endothelial cell apoptosis by the antivascular agent 5,6-dimethylxanthenone-4-acetic acid  

Microsoft Academic Search

5,6-Dimethylxanthenone-4-acetic acid, synthesised in this laboratory, reduces tumour blood flow, both in mice and in patients on Phase I trial. We used TUNEL (TdT-mediated dUTP nick end labelling) assays to investigate whether apoptosis induction was involved in its antivascular effect. 5,6-Dimethylxanthenone-4-acetic acid induced dose-dependent apoptosis in vitro in HECPP murine endothelial cells in the absence of up-regulation of mRNA for

L-M Ching; Z Cao; C Kieda; S Zwain; M B Jameson; B C Baguley

2002-01-01

233

Polycarboxylic acids containing acetal functions: calcium sequestering compounds based on oxidized carbohydrates  

Microsoft Academic Search

A number of polycarboxylic acids containing acetal functions have been prepared by a two-step oxidation of carbohydrates.\\u000a Their calcium sequestering behavior is compared with that of a series of model polycarboxylic acids. It is found that calcium\\u000a sequestration by oxidized carbohydrates is less than that by corresponding ether polycarboxylates, since (a) acetal oxygens\\u000a have a lower coordinating power than ether

M. S. Nieuwenhuizen; A. P. G. Kieboom; H. van Bekkum

1983-01-01

234

Corrosion resistance of 316L stainless steel in acetic acid by EIS and Mott-Schottky  

Microsoft Academic Search

The properties of the passivation film formed on 316L stainless steel were studied by Electrochemical Impedance Spectroscopy\\u000a (EIS), Mott-Schottky and Voltammetry measurements in high-temperature acetic acid. The results show that the passivation film\\u000a formed on 316L stainless steel is stable in 60% acetic acid solution from 25 °C to 85 °C. As temperature increased, the polarization\\u000a resistance decreased but the

Xuequn Cheng; Xiaogang Li; Lixia Yang; Cuiwei Du

2008-01-01

235

FeCl3\\/Acetic Acid-mediated Reverse Atom Transfer Radical Polymerization of Acrylonitrile  

Microsoft Academic Search

Reverse atom transfer radical polymerization (RATRP) has been successfully applied in the synthesis of polyacrylonitrile (PAN) with FeCl3\\/acetic acid as catalyst in the presence of conventional initiator azobisisobutyronitrile (AIBN) at 65°C in N,N-dimethylformamide (DMF). A FeCl3 to acetic acid ratio of 1:2 not only gave better control on polymer's molecular weight and its distribution, but also provided a rapid polymerization

Jing Ma; Hou Chen; Guangxi Zong; Chunhua Wang; Delong Liu

2010-01-01

236

Effect of acetic and tartaric acid upon the thermal decomposition of CaCO 3  

Microsoft Academic Search

In the present work the effect of acetic and tartaric acid upon the thermal decomposition of CaCO3 has been studied. Mixtures of CaC03 and 5, 10 and 20% acetic and tartaric acid have been prepared. These mixtures were heated at various temperatures in order to study the progress of calcium carbonate decomposition by loss on ignition measurements. Differential Scanning Calorimetric

V. Kasselouri; G. Dimopoulos; G. Parissakis

1995-01-01

237

Production of acetic acid by Dekkera\\/Brettanomyces yeasts under conditions of constant pH  

Microsoft Academic Search

Sixty yeast strains were previously screened for their ability to produce acetic acid, in shaken flask batch culture, from either glucose or ethanol. Seven of the strains belonging to the Brettanomyces and Dekkera genera, from the ARS Culture Collection, Peoria, IL, were further evaluated for acetic acid production in bioreactor batch culture at 28 °C, constant aeration (0.75 v\\/v\\/m) and

S. N. Freer; B. Dien; S. Matsuda

2003-01-01

238

Asaia lannaensis sp. nov., a new acetic acid bacterium in the Alphaproteobacteria.  

PubMed

Asaia lannaensis sp. nov. was described for two strains isolated from flowers of the spider lily collected in Chiang Mai, Thailand. The isolates produced acetic acid from ethanol on ethanol/calcium carbonate agar, differing from the type strains of Asaia bogorensis, Asaia siamensis, and Asaia krungthepensis, but did not grow in the presence of 0.35% acetic acid (v/v). The new species is the fourth of the genus Asaia, the family Acetobacteraceae. PMID:18323663

Malimas, Taweesak; Yukphan, Pattaraporn; Takahashi, Mai; Kaneyasu, Mika; Potacharoen, Wanchern; Tanasupawat, Somboon; Nakagawa, Yasuyoshi; Tanticharoen, Morakot; Yamada, Yuzo

2008-03-07

239

Use of titanium in the manufacture of equipment for acetic acid production  

Microsoft Academic Search

In the production of acetic acid from methanol and carbon monoxide with the use of iodine compounds as the catalyst,tantalu m, zirconium, Hastelloy type alloys, and molybdenumcontaining steels are used for the production of equipment. The production medium for the acid in the stage of synthesis and purification at I00-185~ contains up to 17% water, methyl acetate, methyl iodide, methanol,

L. M. Pischik; A. I. Tsinman; N. I. Bal'vas

1983-01-01

240

Preliminary analysis of Monterey kerogen by mild stepwise oxidation with sodium dichromate in glacial acetic acid  

Microsoft Academic Search

Kerogen from Monterey shale was degraded by a controlled, mild stepwise oxidation with sodium dichromate in acetic acid. The products of each step were examined by capillary gas chromatography and combined gas chromatography-mass spectrometry analyses of their methyl esters. Major oxidation products were saturated normal monocarboxylic acids (C 6 -C 34 ), saturated normal , -dicarboxylic acids (C 4 -C

A. O. Barakat; T. F. Yen

1988-01-01

241

Atmospheric Acetic Acid Pulping of Rice Straw IV: PhysicoChemical Characterization of Acetic Acid Lignins from Rice Straw and Woods. Part 1. Physical Characteristics  

Microsoft Academic Search

Summary Lignins obtained by atmospheric acetic acid delignification of rice straw, birch and fir were characterized by molecular weight, solubility and thermomechanical analysis, and by ultraviolet (UV), Fourier transform infra-red (FTIR) and 13 C-NMR spectroscopy. Rice straw lignins (rice lignins) were very different from birch and fir lignins. The former was difficult to dissolve in most tested solvents and infusible

Xue-Jun Pan; Yoshihiro Sano

1999-01-01

242

Atmospheric Acetic Acid Pulping of Rice Straw IV: PhysicoChemical Characterization of Acetic Acid Lignins from Rice Straw and Woods. Part 2. Chemical Structures  

Microsoft Academic Search

Summary Acetic acid lignins from rice straw (RLs), birch (BL) and fir (FL) were chemically characterized by means of elementary analysis, functional groups analysis, alkaline nitrobenzene and permanganate oxi- dation, Mannich reactivity and other techniques. The results showed that RLs had higher contents of residual polysaccharide and protein, and remarkably fewer acetyl groups than BL and FL. Results of nitrobenzene

Xue-Jun Pan; Yoshihiro Sano

1999-01-01

243

Comparison of Lactic Acid Bacteria Fermentation with Acid Treatments for Chitosan Production from Shrimp Waste  

Microsoft Academic Search

The traditional procedure for chitosan production involves use of a strong acid (HCl) for demineralization of chitin. This study reports application of a mixed culture of lactic acid bacteria (Lactobacillus plantarum, Lactobacillus acidophilus, and Lactobacillus lactis) fermentation in demineralization of chitin for chitosan production from shrimp waste. Chitosan produced from shrimp waste with lactic acid bacteria fermentation at 30°C for

Sureerat Phuvasate; Yi-Cheng Su

2010-01-01

244

Metabolite Profiles of Lactic Acid Bacteria in Grass Silage?  

PubMed Central

The metabolite production of lactic acid bacteria (LAB) on silage was investigated. The aim was to compare the production of antifungal metabolites in silage with the production in liquid cultures previously studied in our laboratory. The following metabolites were found to be present at elevated concentrations in silos inoculated with LAB strains: 3-hydroxydecanoic acid, 2-hydroxy-4-methylpentanoic acid, benzoic acid, catechol, hydrocinnamic acid, salicylic acid, 3-phenyllactic acid, 4-hydroxybenzoic acid, (trans, trans)-3,4-dihydroxycyclohexane-1-carboxylic acid, p-hydrocoumaric acid, vanillic acid, azelaic acid, hydroferulic acid, p-coumaric acid, hydrocaffeic acid, ferulic acid, and caffeic acid. Among these metabolites, the antifungal compounds 3-phenyllactic acid and 3-hydroxydecanoic acid were previously isolated in our laboratory from liquid cultures of the same LAB strains by bioassay-guided fractionation. It was concluded that other metabolites, e.g., p-hydrocoumaric acid, hydroferulic acid, and p-coumaric acid, were released from the grass by the added LAB strains. The antifungal activities of the identified metabolites in 100 mM lactic acid were investigated. The MICs against Pichia anomala, Penicillium roqueforti, and Aspergillus fumigatus were determined, and 3-hydroxydecanoic acid showed the lowest MIC (0.1 mg ml?1 for two of the three test organisms).

Broberg, Anders; Jacobsson, Karin; Strom, Katrin; Schnurer, Johan

2007-01-01

245

Reaction engineering analysis of hydrogenotrophic production of acetic acid by Acetobacterium woodii.  

PubMed

Great interest has emerged in biological CO?-fixing processes in the context of current climate change discussions. One example for such a process is the hydrogenotrophic production of acetic acid by anaerobic microorganisms. Acetogenic microorganisms make use of carbon dioxide in the presence of hydrogen to produce acetic acid and biomass. In order to establish a process for the hydrogenotrophic production of acetic acid, the formation of acetate by Acetobacterium woodii was studied in a batch-operated stirred-tank bioreactor at different hydrogen partial pressures (pH?) in the gas phase. The volumetric productivity of the batch processes increased with increasing hydrogen partial pressure. A maximum of the volumetric productivity of 7.4 g(acetate)?L?¹?day?¹ was measured at a pH? of 1,700 mbar. At this pH(2) a final acetate concentration of 44 g L?¹ was measured after a process time of 11 days, if the pH was controlled at pH 7.0 (average cell density of 1.1 g L?¹ cell dry weight). The maximum cell specific actetate productivity was 6.9 g(acetate)?g(cdw)?¹?day?¹ under hydrogenotrophic conditions. PMID:20830677

Demler, Martin; Weuster-Botz, Dirk

2011-02-01

246

Microwave Spectroscopy and Proton Transfer Dynamics in the Formic Acid-Acetic Acid Dimer  

NASA Astrophysics Data System (ADS)

The rotational spectrum of the doubly hydrogen-bonded {hetero} dimer formed between formic acid and acetic acid has been recorded between 4 and 18 GHz using a pulsed-nozzle Fourier transform microwave spectrometer. Each rigid-molecule rotational transition is split into four as a result of two concurrent tunnelling motions, one being proton transfer between the two acid molecules, and the other the torsion/rotation of the methyl group within the acetic acid. We present a full assignment of the spectrum for {J} = 1 to {J} = 7 for these four torsion/tunnelling states. Spectra have been observed for the main isotopic species, with deuterium substitution at the C of the formic acid and all 13C species in natural abundance, The observed transitions are fitted to within a few kilohertz using a molecule-fixed effective rotational Hamiltonian for the separate {A} and {E} vibrational species of the G12 permutation-inversion group which is applicable to this complex. To reduce the effects of internal angular momentum, a non-principal axis system is used throughout. Interpretation of the internal motion uses an internal-vibration and overall rotation scheme, and full sets of rotational and centrifugal distortion constants are determined. The proton tunnelling rates and the internal angular momentum of the methyl group in the {E} states is interpreted in terms of a dynamical model which involves coupled proton transfer and internal rotation. The resulting potential energy surface not only describes these internal motions, but can also explain the observed shifts in rotational constants between {A} and {E} species, and the deviations of the tunnelling frequencies from the expected 2:1 ratio. It also permits the determination of spectral constants free from the contamination effects of the internal dynamics. M.C.D. Tayler, B. Ouyang and B.J. Howard, J. Chem. Phys., {134}, 054316 (2011).

Howard, B. J.; Steer, E.; Page, F.; Tayler, M.; Ouyang, B.; Leung, H. O.; Marshall, M. D.; Muenter, J. S.

2012-06-01

247

Production of the phytohormone indole-3-acetic acid by estuarine species of the genus Vibrio.  

PubMed

Strains of Vibrio spp. isolated from roots of the estuarine grasses Spartina alterniflora and Juncus roemerianus produce the phytohormone indole-3-acetic acid (IAA). The colorimetric Salkowski assay was used for initial screening of IAA production. Gas chromatography-mass spectroscopy (GC-MS) was then employed to confirm and quantify IAA production. The accuracy of IAA quantification by the Salkowski assay was examined by comparison to GC-MS assay values. Indole-3-acetamide, an intermediate in IAA biosynthesis by the indole-3-acetamide pathway, was also identified by GC-MS. Multilocus sequence typing of concatenated 16S rRNA, recA, and rpoA genes was used for phylogenetic analysis of environmental isolates within the genus Vibrio. Eight Vibrio type strains and five additional species-level clades containing a total of 16 environmental isolates and representing five presumptive new species were identified as IAA-producing Vibrio species. Six additional environmental isolates similar to four of the Vibrio type strains were also IAA producers. To our knowledge, this is the first report of IAA production by species of the genus Vibrio or by bacteria isolated from an estuarine environment. PMID:19218411

Gutierrez, Casandra K; Matsui, George Y; Lincoln, David E; Lovell, Charles R

2009-02-13

248

Asaia krungthepensis sp. nov., an acetic acid bacterium in the alpha-Proteobacteria.  

PubMed

Three bacterial strains were isolated from flowers collected in Bangkok, Thailand, by an enrichment-culture approach for acetic acid bacteria. Phylogenetic analysis based on 16S rRNA gene sequences showed that the isolates were located in the lineage of the genus Asaia but constituted a cluster separate from the type strains of Asaia bogorensis and Asaia siamensis. The DNA base composition of the isolates was 60.2-60.5 mol% G+C, with a range of 0.3 mol%. The isolates constituted a taxon separate from Asaia bogorensis and Asaia siamensis on the basis of DNA-DNA relatedness. The isolates had morphological, physiological, biochemical and chemotaxonomic characteristics similar to those of the type strains of Asaia bogorensis and Asaia siamensis, but the isolates grew on maltose. The major ubiquinone was Q(10). On the basis of the results obtained, the name Asaia krungthepensis sp. nov. is proposed for the isolates. The type strain is isolate AA08(T) (=BCC 12978(T)=TISTR 1524(T)=NBRC 100057(T)=NRIC 0535(T)), which had a DNA G+C content of 60.3 mol% and was isolated from a heliconia flower ('paksaasawan' in Thai; Heliconia sp.) collected in Bangkok, Thailand. PMID:15023938

Yukphan, Pattaraporn; Potacharoen, Wanchern; Tanasupawat, Somboon; Tanticharoen, Morakot; Yamada, Yuzo

2004-03-01

249

High hydrostatic pressure inactivation of total aerobic bacteria, lactic acid bacteria, yeasts in sour Chinese cabbage  

Microsoft Academic Search

This study investigated the inactivation of total aerobic bacteria (TAB), lactic acid bacteria (LAB), yeasts in sour Chinese cabbage (SCC) treated by high hydrostatic pressure (HHP). The pressure level ranged from 200 to 600MPa and the treatment time were 10–30min. All samples were stored at 4, 27 and 37°C for 90days. The pressure level of 200MPa had no significant impact

Lin Li; Lun Feng; Junjie Yi; Cheng Hua; Fang Chen; Xiaojun Liao; Zhengfu Wang; Xiaosong Hu

2010-01-01

250

Metabolism of Indole-3-acetic Acid: IV. Biological Properties of Amino Acid Conjugates.  

PubMed

The biological activity of 20 l-alpha-amino acid conjugates of indole-3-acetic acid (IAA) to stimulate cell elongation of Avena sativa coleoptile sections and to stimulate growth of soybean cotyledon tissue cultures has been examined at concentrations of 10(-4) to 10(-7)m. In the Avena coleoptile test, most of the amino acid conjugates stimulated elongation. Several of the conjugates stimulated as much elongation as IAA but their half-maximum concentrations tended to be higher. Some of the more active conjugates were alanine, glycine, lysine, serine, aspartic acid, cystine, cysteine, methionine, and glutamic acid.In the soybean cotyledon tissue culture test, all of the l-alpha-amino acid conjugates of IAA stimulated growth except for the phenylalanine, histidine, and arginine conjugates. Most of the conjugates produced responses at least as great as that caused by IAA. Conjugates with half-maximum concentrations lower than IAA included cysteine, cystine, methionine, and alanine. These conjugates exceed the IAA-induced callus growth at all tested concentrations. Other conjugates significantly better than IAA at 10(-6)m were serine, glycine, leucine, proline, and threonine. PMID:16659795

Feung, C S; Hamilton, R H; Mumma, R O

1977-01-01

251

Influence of Medium Buffering Capacity on Inhibition of Saccharomyces cerevisiae Growth by Acetic and Lactic Acids  

PubMed Central

Acetic acid (167 mM) and lactic acid (548 mM) completely inhibited growth of Saccharomyces cerevisiae both in minimal medium and in media which contained supplements, such as yeast extract, corn steep powder, or a mixture of amino acids. However, the yeast grew when the pH of the medium containing acetic acid or lactic acid was adjusted to 4.5, even though the medium still contained the undissociated form of either acid at a concentration of 102 mM. The results indicated that the buffer pair formed when the pH was adjusted to 4.5 stabilized the pH of the medium by sequestering protons and by lessening the negative impact of the pH drop on yeast growth, and it also decreased the difference between the extracellular and intracellular pH values (?pH), the driving force for the intracellular accumulation of acid. Increasing the undissociated acetic acid concentration at pH 4.5 to 163 mM by raising the concentration of the total acid to 267 mM did not increase inhibition. It is suggested that this may be the direct result of decreased acidification of the cytosol because of the intracellular buffering by the buffer pair formed from the acid already accumulated. At a concentration of 102 mM undissociated acetic acid, the yeast grew to higher cell density at pH 3.0 than at pH 4.5, suggesting that it is the total concentration of acetic acid (104 mM at pH 3.0 and 167 mM at pH 4.5) that determines the extent of growth inhibition, not the concentration of undissociated acid alone.

Thomas, K. C.; Hynes, S. H.; Ingledew, W. M.

2002-01-01

252

Radiofrequency Thermal Ablation: Increase in Lesion Diameter with Continuous Acetic Acid Infusion  

SciTech Connect

Purpose. To evaluate the influence of continuous infusion of acetic acid 50% during radiofrequency ablation (RFA) on the size of the thermal lesion produced. Methods. Radiofrequency (RF) was applied to excised bovine liver by using an expandable needle electrode with 10 retractable tines (LeVeen Needle Electrode, RadioTherapeutics, Sunnyvale, CA) connected to a commercially available RF generator (RF 2000, RadioTherapeutics, Sunnyvale, CA). Experiments were performed using three different treatment modalities: RF only (n = 15), RF with continuous saline 0.9% infusion (n = 15), and RF with continuous acetic acid 50% infusion (n = 15). RF duration, power output, tissue impedance, and time to a rapid rise in impedance were recorded. The ablated lesions were evaluated both macroscopically and histologically. Results. The ablated lesions appeared as spherical or ellipsoid, well-demarcated pale areas with a surrounding brown rim with both RF only and RF plus saline 0.9% infusion. In contrast, thermolesions generated with RF in combination with acetic acid 50% infusion were irregular in shape and the central portion was jelly-like. Mean diameter of the coagulation necrosis was 22.3 {+-} 2.1 mm (RF only), 29.2 {+-} 4.8 mm (RF + saline 0.9%) and 30.7 {+-} 5.7 mm (RF + acetic acid 50%), with a significant increase in the RF plus saline 0.9% and RF plus acetic acid 50% groups compared with RF alone. Time to a rapid rise in impedance was significantly prolonged in the RF plus saline 0.9% and RF plus acetic acid 50% groups compared with RF alone. Conclusions. A combination of RF plus acetic acid 50% infusion is able to generate larger thermolesions than RF only or RF combined with saline 0.9% infusion.

Lubienski, Andreas [Ruprecht-Karls-University Heidelberg, Department of Diagnostic Radiology (Germany)], E-mail: lubienski@radiologie.uni-luebeck.de; Duex, Markus [Hospital Northwest Frankfurt, Department of Radiology (Germany); Lubienski, Katrin; Grenacher, Lars; Kauffmann, Guenter [Ruprecht-Karls-University Heidelberg, Department of Diagnostic Radiology (Germany)

2005-12-15

253

Fermentation of beet juice by beneficial lactic acid bacteria  

Microsoft Academic Search

Red beets were evaluated as a potential substrate for the production of probiotic beet juice by four species of lactic acid bacteria (Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus delbrueckii, Lactobacillus plantarum). All the lactic cultures were found capable of rapidly utilizing beet juice for cell synthesis and lactic acid production. However, L. acidophilus and L. plantarum produced a greater amount of

Kyung Young Yoon; Edward E. Woodams; Yong D. Hang

2005-01-01

254

Bacteriocins from Lactic Acid Bacteria: Production, Purification, and Food Applications  

Microsoft Academic Search

In fermented foods, lactic acid bacteria (LAB) display numerous antimicrobial activities. This is mainly due to the production of organic acids, but also of other compounds, such as bacteriocins and antifungal peptides. Several bacteriocins with industrial potential have been purified and characterized. The kinetics of bacteriocin production by LAB in relation to process factors have been studied in detail through

Luc De Vuyst; Frédéric Leroy

2007-01-01

255

Remediation of Acid Mine Drainage with Sulfate Reducing Bacteria  

ERIC Educational Resources Information Center

|Sulfate reducing bacteria have been shown to be effective at treating acid mine drainage through sulfide production and subsequent precipitation of metal sulfides. In this laboratory experiment for undergraduate environmental chemistry courses, students design and implement a set of bioreactors to remediate acid mine drainage and explain observed…

Hauri, James F.; Schaider, Laurel A.

2009-01-01

256

Psychrotrophic, lactic acid-producing bacteria from anoxic waters in Ace Lake, Antarctica; Carnobacterium funditum sp. nov. and Carnobacterium alterfunditum sp. nov  

Microsoft Academic Search

Heterofermentative, lactic acid-producing, gram-positive, motile bacteria were isolated from the waters of Ace Lake, Antarctica. All strains produced virtually only l(+)lactic acid from d(+)glucose. d(-)ribose was fermented to lactic, acetic, and formic acids, and ethanol. Cell walls contained meso-diaminopimaleic acid. The strains did not grow at 30°C and were psychrotrophic. Whole cells contained 18:1cis 9 as a major component of

P. D. Franzmann; P. Höpfl; N. Weiss; B. J. Tindall

1991-01-01

257

A laboratory study of the effect of acetic acid vapor on atmospheric copper corrosion  

SciTech Connect

A study was made of the copper corrosion rate and corrosion products originated by the action of acetic acid vapor at 100% relative humidity. Copper plates were exposed to an acetic acid contaminated atmosphere for a period of 21 days. Five acetic vapor concentration levels were used. The copper corrosion rate was in the range of 1 to 23 mg/dm{sup 2} day. The corrosion-product layers were characterized using electrochemical, X-ray powder diffraction, Fourier transform infrared spectrometry, and scanning electron microscopy techniques. Thermal and calorimetric studies were also performed. Some of the compounds identified were cuprite (Cu{sub 2}O), copper acetate hydrate [Cu(CH{sub 3}COO){sub 2}{center_dot}2H{sub 2}O], and copper hydroxide acetate [Cu{sub 4}(OH)(CH{sub 3}COO){sub 7}{center_dot}2H{sub 2}O]. This last compound was also characterized. The thickness of the patina layers was 4 to 8 nm for amorphous cuprite, 11 to 48 nm for cuprite, and 225 nm for copper acetate. The patina, in which the cementation process of different corrosion-product layers plays an important role, is formed by the reaction of acetic vapor with copper through porous cuprite paths.

Lopez-Delgado, A.; Cano, E.; Bastidas, J.M.; Lopez, F.A. [Centro Nacional de Investigaciones Metalurgicas, Madrid (Spain)

1998-12-01

258

Preliminary analysis of monterey kerogen by mild stepwise oxidation with sodium dichromate in glacial acetic acid  

Microsoft Academic Search

Kerogen from Monterey shale was degraded by a controlled, mild stepwise oxidation with sodium dichromate in acetic acid. The products of each step were examined by capillary gas chromatography and combined gas chromatography-mass spectrometry analyses of their methyl esters. Major oxidation products were saturated normal monocarboxylic acids (Câ-Cââ), saturated normal, ..cap alpha..,omega-dicarboxylic acids (Câ-Cââ), and isoprenoid acids (Cââ-Cââ, except Cââ).

A. O. Barakat; T. F. Yen

1988-01-01

259

Modeling of yeast Brettanomyces bruxellensis growth at different acetic acid concentrations under aerobic and anaerobic conditions.  

PubMed

Glucose utilization by Brettanomyces bruxellensis at different acetic acid concentrations under aerobic and anaerobic conditions was investigated. The presence of the organic acid disturbs the growth and fermentative activity of the yeast when its concentration exceeds 2 g l(-1). A mathematical model is proposed for the kinetic behavior analysis of yeast growing in batch culture. A Matlab algorithm was used for estimation of model parameters, whose confidence intervals were also calculated at a 0.95 probability level using a t-Student distribution for f degrees of freedom. The model successfully simulated the batch kinetics observed at different concentrations of acetic acid under both oxygen conditions. PMID:17622565

Yahara, Garcia Alvarado; Javier, Mendez Ancona; Tulio, Mata Jimenez Marco; Javier, Gómez Rodriguez; Guadalupe, Aguilar Uscanga Maria

2007-07-11

260

Role of ascorbic acid in lead acetate induced lipid peroxidation and hemolysis in human RBC  

Microsoft Academic Search

Lipid peroxidation and hemolysis in humand red blood cells (RBCs) increased on their exposure to increasing concentrations\\u000a of lead acetate (0.01–1.0mM). However pretreatment of RBCs with ascorbic acid (2mM and 4mM) significantly reduced the effect\\u000a of lead acetate on lipid peroxidation and hemolysis in human RBCs.

G. L. Soni; A. K. Bansal; N. Malhotra

1992-01-01

261

Effect of Acetic Acid on Growth and Ethanol Fermentation of Xylose Fermenting Yeast and Saccharomyces cerevisiae  

Microsoft Academic Search

Growth of some xylose fermenting yeasts, Candida shehatae, Pichia stipitis CBS5773, fusant F101 and fusant F198, was completely inhibited in xylose medium added with 0.5% v\\/v acetic acid which caused the reduction of pH to 4.1. Only one xylose fermenting strain, Pachysolen tannophilus NRRL-Y2460, showed relatively low growth and ethanol fermentation. However, in the medium added with 1.0% v\\/v acetic

Savitree Limtong; Tawatchai Sumpradit; Vichien Kitpreechavanich; Manee Tuntirungkij; Tatsuji Seki; Toshiomi Yoshida

262

Equations and calculations for fermentations of butyric acid bacteria  

Microsoft Academic Search

Saccharolytic clostridia grow anaerobically on a variety of substrates, can produce a large number of useful prod- uct~,~-~ and thus appear to be very promising bacteria for production of organic chemicals from mono-, oligo-, and polysaccharides. Butyric acid bacteria (clostridia) in par- ticular, can anaerobically ferment a variety of sugars (hex- oses, pentoses, and oligosac~harides )~~~~~ to produce a variety

Eleftherios Terry Papoutsakis

1984-01-01

263

Occurrence and role of lactic acid bacteria in seafood products  

Microsoft Academic Search

Lactic acid bacteria (LAB) in fish flesh has long been disregarded because the high post-mortem pH, the low percentage of sugars, the high content of low molecular weight nitrogenous molecules and the low temperature of temperate waters favor the rapid growth of pH-sensitive psychrotolerant marine Gram-negative bacteria like Pseudomonas, Shewanella and Photobacterium. In seafood packed in both vacuum (VP) and modified atmosphere

Leroi Françoise

2010-01-01

264

Lantibiotics produced by lactic acid bacteria: structure, function and applications  

Microsoft Academic Search

Lantibiotics are a diverse group of heavily modified antimicrobial and\\/or signalling peptides produced by a wide range of bacteria, including a variety of lactic acid bacteria. Based on their diverse structures and mode of action, at least six separate lantibiotic subgroups can be suggested, but all subgroups are characterized by significant post-translational modifications, which include the formation of (ß-methyl)lanthionines, among

Denis Twomey; R. P. Ross; Maire Ryan; Billy Meaney; C. Hill

2002-01-01

265

Perspectives of engineering lactic acid bacteria for biotechnological polyol production  

Microsoft Academic Search

Polyols are sugar alcohols largely used as sweeteners and they are claimed to have several health-promoting effects (low-caloric,\\u000a low-glycemic, low-insulinemic, anticariogenic, and prebiotic). While at present chemical synthesis is the only strategy able\\u000a to assure the polyol market demand, the biotechnological production of polyols has been implemented in yeasts, fungi, and\\u000a bacteria. Lactic acid bacteria (LAB) are a group of

Vicente Monedero; Gaspar Pérez-Martínez; María J. Yebra

2010-01-01

266

Volatile acetic acid and formaldehyde emission from plywood treated with boron compound  

Microsoft Academic Search

The effects of plywood on formaldehyde and volatile acetic acid emissions treated with borax and boric acid were investigated. The treated plywood samples were manufactured by using two different methods; each veneer was first impregnated by a dipping method before the first group of plywood was manufactured. The second group of plywood panels was produced by adding preservatives (borax, boric

S. Colak; G. Colakoglu

2004-01-01

267

Hydrogen production by catalytic steam reforming of acetic acid, a model compound of biomass pyrolysis liquids  

Microsoft Academic Search

An environmentally friendly and cost-competitive way of producing hydrogen is the catalytic steam reforming of biomass pyrolysis liquids, known as bio-oil, which can be separated into two fractions: ligninic and aqueous. Acetic acid has been identified as one of the major organic acids present in the latter, and catalytic steam reforming has been studied for this model compound. Three different

F. Bimbela; M. Oliva; J. Ruiz; L. García; J. Arauzo

2007-01-01

268

Genesis of Acetate and Methane by Gut Bacteria of Nutritionally Diverse Termites  

Microsoft Academic Search

The evolution of different feeding guilds in termites is paralleled by differences in the activity of their gut microbiota. In wood-feeding termites, carbon dioxide-reducing acetogenic bacteria were found to generally outprocess carbon dioxide-reducing methanogenic bacteria for reductant (presumably hydrogen) generated during microbial fermentation in the hindgut. By contrast, acetogenesis from hydrogen and carbon dioxide was of little significance in fungus-growing

Alain Brauman; Matthew D. Kane; Marc Labat; John A. Breznak

1992-01-01

269

Fermentation of pomegranate juice by probiotic lactic acid bacteria  

Microsoft Academic Search

In this research, production of probiotic pomegranate juice through its fermentation by four strains of lactic acid bacteria:\\u000a Lactobacillus plantarum, L. delbruekii, L. paracasei, L. acidophilus was examined. Fermentation was carried out at 30°C for 72 h under microaerophilic conditions. Microbial population, pH, titrable\\u000a acidity, sugar and organic acid metabolism were measured during the fermentation period and the viability of all

Z. E. Mousavi; S. M. Mousavi; S. H. Razavi; Z. Emam-Djomeh; H. Kiani

2011-01-01

270

Acetic acid detection threshold in synthetic wine samples of a portable electronic nose.  

PubMed

Wine quality is related to its intrinsic visual, taste, or aroma characteristics and is reflected in the price paid for that wine. One of the most important wine faults is the excessive concentration of acetic acid which can cause a wine to take on vinegar aromas and reduce its varietal character. Thereby it is very important for the wine industry to have methods, like electronic noses, for real-time monitoring the excessive concentration of acetic acid in wines. However, aroma characterization of alcoholic beverages with sensor array electronic noses is a difficult challenge due to the masking effect of ethanol. In this work, in order to detect the presence of acetic acid in synthetic wine samples (aqueous ethanol solution at 10% v/v) we use a detection unit which consists of a commercial electronic nose and a HSS32 auto sampler, in combination with a neural network classifier (MLP). To find the characteristic vector representative of the sample that we want to classify, first we select the sensors, and the section of the sensors response curves, where the probability of detecting the presence of acetic acid will be higher, and then we apply Principal Component Analysis (PCA) such that each sensor response curve is represented by the coefficients of its first principal components. Results show that the PEN3 electronic nose is able to detect and discriminate wine samples doped with acetic acid in concentrations equal or greater than 2 g/L. PMID:23262483

Macías, Miguel Macías; Manso, Antonio García; Orellana, Carlos Javier García; Velasco, Horacio Manuel González; Caballero, Ramón Gallardo; Chamizo, Juan Carlos Peguero

2012-12-24

271

Acetic Acid Detection Threshold in Synthetic Wine Samples of a Portable Electronic Nose  

PubMed Central

Wine quality is related to its intrinsic visual, taste, or aroma characteristics and is reflected in the price paid for that wine. One of the most important wine faults is the excessive concentration of acetic acid which can cause a wine to take on vinegar aromas and reduce its varietal character. Thereby it is very important for the wine industry to have methods, like electronic noses, for real-time monitoring the excessive concentration of acetic acid in wines. However, aroma characterization of alcoholic beverages with sensor array electronic noses is a difficult challenge due to the masking effect of ethanol. In this work, in order to detect the presence of acetic acid in synthetic wine samples (aqueous ethanol solution at 10% v/v) we use a detection unit which consists of a commercial electronic nose and a HSS32 auto sampler, in combination with a neural network classifier (MLP). To find the characteristic vector representative of the sample that we want to classify, first we select the sensors, and the section of the sensors response curves, where the probability of detecting the presence of acetic acid will be higher, and then we apply Principal Component Analysis (PCA) such that each sensor response curve is represented by the coefficients of its first principal components. Results show that the PEN3 electronic nose is able to detect and discriminate wine samples doped with acetic acid in concentrations equal or greater than 2 g/L.

Macias, Miguel Macias; Manso, Antonio Garcia; Orellana, Carlos Javier Garcia; Velasco, Horacio Manuel Gonzalez; Caballero, Ramon Gallardo; Chamizo, Juan Carlos Peguero

2013-01-01

272

Brettanomyces bruxellensis: effect of oxygen on growth and acetic acid production.  

PubMed

The influence of the oxygen supply on the growth, acetic acid and ethanol production by Brettanomyces bruxellensis in a glucose medium was investigated with different air flow rates in the range 0-300 l h(-1 ) x (0-0.5 vvm). This study shows that growth of this yeast is stimulated by moderate aeration. The optimal oxygen supply for cellular synthesis was an oxygen transfer rate (OTR) of 43 mg O(2) l(-1) x h(-1). In this case, there was an air flow rate of 60 l h(-1) (0.1 vvm). Above this value, the maximum biomass concentration decreased. Ethanol and acetic acid production was also dependent on the level of aeration: the higher the oxygen supply, the greater the acetic acid production and the lower the ethanol production. At the highest aeration rates, we observed a strong inhibition of the ethanol yield. Over 180 l h(-1) x (0.3 vvm, OTR =105 mg O(2) l(-1) x h(-1)), glucose consumption was inhibited and a high concentration of acetic acid (6.0 g x l(-1)) was produced. The ratio of "ethanol + acetic acid" produced per mole of consumed glucose using carbon balance calculations was analyzed. It was shown that this ratio remained constant in all cases. This makes it possible to establish a stoichiometric equation between oxygen supply and metabolite production. PMID:12655458

Aguilar Uscanga, M G; Délia, M-L; Strehaiano, P

2003-01-14

273

Conductance of HCl, NaCl, Na acetate, and acetic acid in water-ethylene carbonate solvent mixtures at 25 and 40°C  

Microsoft Academic Search

The molar conductances of solutions of hydrochloric acid, sodium chloride, sodium acetate, and acetic acid were measured in water-ethylene carbonate (EC) solvent mixtures at 25 and 40°C. These solvents have dielectric constants higher than that of water. Four solvent compositions, in which the mole fraction (x2) of EC was 0.2, 0.4, 0.5, and 0.6, were studied at 25°C. For HCl

Barry R. Boerner; Roger G. Bates

1978-01-01

274

Changes in indole-3-acetic acid, indole-3-acetic acid oxidase, and peroxidase isoenzymes in the seeds of developing peach fruits  

Microsoft Academic Search

Changes in indole-3-acetic acid (IAA) content of peach (Prunus persica L. Batsch cv. Merry) seeds were followed during fruit development. The highest concentration of IAA, 2.7 ?g\\/g fresh weight,\\u000a was found at the beginning of Stage III of fruit development, approximately 50–60 days after anthesis. The IAA-decarboxylating\\u000a capacity of crude extracts of seeds was also greatest at 55–60 days after

Victoriano Valpuesta; Miguel A. Quesada; Cristina Sánchez-Roldán; Horacio A. Tigier; Antonio Heredia; Martin J. Bukovac

1989-01-01

275

In vivo characterization of horseradish peroxidase with indole-3-acetic acid and 5-bromoindole-3-acetic acid for gene therapy of cancer  

Microsoft Academic Search

Gene-directed enzyme prodrug therapy is a form of targeted cancer therapy, in which an enzyme is used to convert a non-toxic prodrug to a cytotoxin within the tumor. Horseradish peroxidase (HRP) is able to convert the indole prodrugs indole-3-acetic acid (IAA) and the halogenated derivative 5-bromo-IAA (5Br-IAA) to toxic agents able to induce cell kill in vitro. This study characterized

J Tupper; M R Stratford; S Hill; G M Tozer; G U Dachs

2010-01-01

276

Effect of acetic acid fumigation on soil-borne fungi and cucumber root rot disease under greenhouse conditions  

Microsoft Academic Search

The effect of acetic acid vapour on soil-borne fungi and root rot disease of cucumber plants under greenhouse conditions was studied. Acetic acid vapour at four concentrations was tested against linear growth and spore germination of some soil-borne fungi, in vitro. The most sensitive fungus to acetic acid vapours was Rhizoctonia solani which inhibited at 4 µl l, while Fusarium solani,

Farid Abd-El-Kareem

2009-01-01

277

[Continuous irrigation of the bladder with acetic acid solution and its therapeutic effect on candida-infection].  

PubMed

Our clinical experience with acetic acid solution in the treatment of candida infection of the bladder was confirmed by in vitro experiments. We apply continuous bladder irrigation with increasing concentrations of acetic acid solution up to pH 5.0. The majority of patients had received antibiotics or cytostatic drugs and suffered from chronic and malignant diseases. A case report is given with endoscopic documentation of the influence of acetic acid solution on the bladder. PMID:234644

Böcker, R; Fröhlich, G

1975-01-01

278

Improving cyclodextrin complexation of a new antihepatitis drug with glacial acetic acid.  

PubMed

The purpose of this study was to develop and evaluate a solid nonaqueous oral dosage form for a new hepatitis C drug, PG301029, which is insoluble and unstable in water. Hydroxypropyl-beta-cyclodextrin (HPbetaCD) and PG301029 were dissolved in glacial acetic acid. The acetic acid was removed by rotoevaporation such that the drug exists primarily in the complexed form. The stability of formulated PG301029 was determined upon dry storage and after reconstitution in simulated intestinal fluid (SIF), simulated gastric fluid (SGF), and water. Formulated PG301029 was found to be stable upon storage and can be reconstituted with water to a concentration 200 times that of the intrinsic solubility. Once reconstituted, the powder dissolves rapidly and PG301029 remains stable for 21 hours in SGF, SIF, and water. The unique use of acetic acid and HPbetaCD results in a solid dosage form of PG301029 that is both soluble and stable in water. PMID:16584148

Johnson, Jennifer L H; He, Yan; Jain, Akash; Yalkowsky, Samuel H

2006-02-24

279

Induction of endothelial cell apoptosis by the antivascular agent 5,6-dimethylxanthenone-4-acetic acid  

PubMed Central

5,6-Dimethylxanthenone-4-acetic acid, synthesised in this laboratory, reduces tumour blood flow, both in mice and in patients on Phase I trial. We used TUNEL (TdT-mediated dUTP nick end labelling) assays to investigate whether apoptosis induction was involved in its antivascular effect. 5,6-Dimethylxanthenone-4-acetic acid induced dose-dependent apoptosis in vitro in HECPP murine endothelial cells in the absence of up-regulation of mRNA for tumour necrosis factor. Selective apoptosis of endothelial cells was detected in vivo in sections of Colon 38 tumours in mice within 30?min of administration of 5,6-Dimethylxanthenone-4-acetic acid (25?mg?kg?1). TUNEL staining intensified with time and after 3?h, necrosis of adjacent tumour tissue was observed. Apoptosis of central vessels in splenic white pulp was also detected in tumour-bearing mice but not in mice without tumours. Apoptosis was not observed in liver tissue. No apoptosis was observed with the inactive analogue 8-methylxanthenone-4-acetic acid. Positive TUNEL staining of tumour vascular endothelium was evident in one patient in a Phase I clinical trial, from a breast tumour biopsy taken 3 and 24?h after infusion of 5,6-Dimethylxanthenone-4-acetic acid (3.1?mg?m?2). Tumour necrosis and the production of tumour tumour necrosis factor were not observed. No apoptotic staining was seen in tumour biopsies taken from two other patients (doses of 3.7 and 4.9?mg?m?2). We conclude that 5,6-Dimethylxanthenone-4-acetic acid can induce vascular endothelial cell apoptosis in some murine and human tumours. The action is rapid and appears to be independent of tumour necrosis factor induction. British Journal of Cancer (2002) 86, 1937–1942. doi:10.1038/sj.bjc.6600368 www.bjcancer.com © 2002 Cancer Research UK

Ching, L-M; Cao, Z; Kieda, C; Zwain, S; Jameson, M B; Baguley, B C

2002-01-01

280

The conjugated auxin indole-3-acetic acid-aspartic acid promotes plant disease development.  

PubMed

Auxin is a pivotal plant hormone that regulates many aspects of plant growth and development. Auxin signaling is also known to promote plant disease caused by plant pathogens. However, the mechanism by which this hormone confers susceptibility to pathogens is not well understood. Here, we present evidence that fungal and bacterial plant pathogens hijack the host auxin metabolism in Arabidopsis thaliana, leading to the accumulation of a conjugated form of the hormone, indole-3-acetic acid (IAA)-Asp, to promote disease development. We also show that IAA-Asp increases pathogen progression in the plant by regulating the transcription of virulence genes. These data highlight a novel mechanism to promote plant susceptibility to pathogens through auxin conjugation. PMID:22374398

González-Lamothe, Rocío; El Oirdi, Mohamed; Brisson, Normand; Bouarab, Kamal

2012-02-28

281

Loading of amphipathic weak acids into liposomes in response to transmembrane calcium acetate gradients  

Microsoft Academic Search

We describe a novel procedure to load amphipathic weak acid molecules into preformed liposomes. Differences in calcium acetate concentrations across the liposomal membrane induce an increase of the internal pH. This pH imbalance serves as an efficient driving force to load and accumulate weak acids (5(6)-carboxyfluorescein and nalidixic acid) inside the lipid vesicles. The mechanism of loading and the relevance

Stéphane Clerc; Yechezkel Barenholz

1995-01-01

282

Acetic acid opens large-conductance Ca2+-activated K+ channels in guinea pig detrusor smooth muscle cells.  

PubMed

Acetic acid was found to have actions on urinary bladder smooth muscle in our routine ion channel screening assays. Numerous studies have examined the mechanisms of bladder irritation by acetic acid; however, the direct effect of acetic acid on ion channels in detrusor smooth muscle cells has not been evaluated. We used whole-cell patch-clamp techniques to examine the effect of acetic acid on large-conductance Ca2+-activated K+ channels (BKCa) from guinea pig detrusor smooth muscle cells and CHO cells expressing recombinant human BKCaalphabeta1 (CHO BKCaalphabeta1) and human BKCaalpha (CHO BKCaalpha). Acetic acid activated BKCa currents in a concentration-dependent (0.01% to 0.05% v/v) manner in all the cell systems studied. Acetic acid (0.05%) increased BKCa current at +30 mV by 2764+/-918% (n=8) in guinea pig detrusor smooth muscle cells. Acetic acid (0.03%) shifted the V1/2 of conductance-voltage curve by 64+/-14 (n=5), 128+/-14 (n=5), and 126+/-12 mV (n=4) in CHO BKCaalpha, CHO BKCaalphabeta1 and detrusor smooth muscle cells, respectively. This effect of acetic acid was found to be independent of pH and was also not produced by its salt form, sodium acetate. Automated patch-clamp experiments also showed similar activation of CHO BKCaalphabeta1 by acetic acid. In conclusion, acetic acid directly activates BKCa channels in detrusor smooth muscle cells. This novel study necessitates caution while interpreting the results from acetic acid bladder irritation model. PMID:17382925

Ghatta, Srinivas; Lozinskaya, Irina; Lin, Zuojun; Gordon, Earl; Willette, Robert N; Brooks, David P; Xu, Xiaoping

2007-02-27

283

Acetic acid production from fructose by clostridium formicoaceticum immobilized in a fibrous-Bed bioreactor  

PubMed

The fermentation kinetics of acetic acid production from fructose by Clostridium formicoaceticum was studied at pH 7.6 and 37 degreesC. Recycle batch, fed-batch, and continuous fermentations using immobilized cells in a fibrous-bed bioreactor were studied for their potential application in producing acetic acid from fructose, a fermentable sugar commonly found in corn steep liquor and many other food processing wastes. For the immobilized cell fermentation, acetic acid yield from fructose was approximately 1.0 g/g, with a final acetate concentration of approximately 78 g/L and the overall reactor productivity (based on the fibrous bed bioreactor volume) of approximately 0.95 g/(L.h) in the fed-batch fermentation. For a similar fed-batch fermentation with free cells, acetic acid yield was approximately 0.9 g/g, the highest final acetate concentration was approximately 46 g/L, and the overall productivity was approximately 0.12 g/(L.h). In the continuous fermentation with immobilized cells, the reactor productivity decreased from 3.2 to 1. 3 g/(L.h) as retention time increased from 16 to 72 h to reach 100% conversion. Compared to free-cell fermentations, the superior performance of the fibrous-bed bioreactor can be attributed to the high density (>30 g/L) of viable cells immobilized in the fibrous bed. The fermentation product, acetic acid, was found to be a noncompetitive inhibitor to the cells. However, the immobilized cells had a higher maximum production rate (pmax) and a higher value for the inhibition rate constant (Kp) than those for the free cells, suggesting that the immobilized cells in the fibrous-bed bioreactor were less sensitive to acetic acid inhibition than the free cells. This improvement in kinetic behaviors for immobilized cells confirms that the fibrous-bed bioreactor can be used as an effective tool for adapting and screening for acetate-tolerant strains. PMID:9758672

Huang; Mann; Novak; Yang

1998-09-01

284

SEPARATING, CHARACTERIZATION AND APPLICATION OF ALFA GRASS (Stipa tenacissima) CHEMICAL COMPONENTS 1. PULPING OF ALFA GRASS WITH FORMIC ACID\\/ACETIC ACID MIXTURE  

Microsoft Academic Search

The pulping of Alfa grass at atmospheric pressure using a mixture of formic acid\\/acetic acid\\/water was investigated. Different pulping variables were studied, especially the percentage of formic acid, acetic acid and water, pulping time, the liquor to fibre ratio and impregnation time. The obtained unbleached pulps were analysed in accordance with the Kappa number and the degree of polymerisation. The

Houcine Ammar; Hichem Mallek; Fatma Abdelkefi; Bouchra Benjelloun-Mlayeh; Rachid El Gharbi

285

Enzymological studies of one-carbon reactions in the pathway of acetate utilization by methanogenic bacteria  

SciTech Connect

Several enzymes in the pathway of acetate conversion to methane and carbon dioxide have been purified from Methanosarcina thermophila. The mechanisms of these enzymes are under investigation utilizing biochemical, biophysical and molecular genetic approaches. Acetate kinase and phosphotransacetylase catalyzes the activation of acetate to acetyl-CoA. The primary structure of these enzymes will be determined through cloning and sequencing of the genes. Two protein components of the CO dehydrogenase complex are under investigations. The metal centers of each component have been characterized using EPR. Cloning and sequencing of the genes for the two subunits of each component is in progress. Results indicate that the Ni/Fe-S component cleaves the C-C and C-S bonds of acetyl-CoA followed by oxidation of the carbonyl group to carbon dioxide and transfer of the methyl group to the Co/Fe-S component. The enzymes and cofactors involved in transfer of the methyl group from the Co/Fe-S component to coenzyme M will be purified and characterized. Ferredoxin is an electron acceptor for the Ni/Fe-S component and also serves to reductively reactivate methylreductase which catalyzes the demethylation of methyl coenzyme M to methane. This ferredoxin is being characterized utilizing EPR and RR spectroscopic methods to determine the properties of the Fe-S centers. Genes encoding this and other ferredoxins have been cloned and sequenced to determine the primary structures. Carbonic anhydrase is being purified and characterized to determine the function of this enzyme in the pathway.

Ferry, J.G.

1991-12-31

286

Enzymological studies of one-carbon reactions in the pathway of acetate utilization by methanogenic bacteria  

SciTech Connect

Several enzymes in the pathway of acetate conversion to methane and carbon dioxide have been purified from Methanosarcina thermophila. The mechanisms of these enzymes are under investigation utilizing biochemical, biophysical and molecular genetic approaches. Acetate kinase and phosphotransacetylase catalyzes the activation of acetate to acetyl-CoA. The primary structure of these enzymes will be determined through cloning and sequencing of the genes. Two protein components of the CO dehydrogenase complex are under investigations. The metal centers of each component have been characterized using EPR. Cloning and sequencing of the genes for the two subunits of each component is in progress. Results indicate that the Ni/Fe-S component cleaves the C-C and C-S bonds of acetyl-CoA followed by oxidation of the carbonyl group to carbon dioxide and transfer of the methyl group to the Co/Fe-S component. The enzymes and cofactors involved in transfer of the methyl group from the Co/Fe-S component to coenzyme M will be purified and characterized. Ferredoxin is an electron acceptor for the Ni/Fe-S component and also serves to reductively reactivate methylreductase which catalyzes the demethylation of methyl coenzyme M to methane. This ferredoxin is being characterized utilizing EPR and RR spectroscopic methods to determine the properties of the Fe-S centers. Genes encoding this and other ferredoxins have been cloned and sequenced to determine the primary structures. Carbonic anhydrase is being purified and characterized to determine the function of this enzyme in the pathway.

Ferry, J.G.

1991-01-01

287

Acetate Induced Enhancement of Photocatalytic Hydrogen Peroxide Production from Oxalic Acid and Dioxygen.  

PubMed

The addition of acetate ion to an O2-saturated mixed solution of acetonitrile and water containing oxalic acid as a reductant and 2-phenyl-4-(1-naphthyl)quinolinium ion (QuPh(+)-NA) as a photocatalyst dramatically enhanced the turnover number of hydrogen peroxide (H2O2) production. In this photocatalytic H2O2 production, a base is required to facilitate deprotonation of oxalic acid forming oxalate dianion, which acts as an actual electron donor, whereas a Brønsted acid is also necessary to protonate O2(•-) for production of H2O2 by disproportionation. The addition of acetate ion to a reaction solution facilitates both the deprotonation of oxalic acid and the protonation of O2(•-) owing to a pH buffer effect. The quantum yield of the photocatalytic H2O2 production under photoirradiation (? = 334 nm) of an O2-saturated acetonitrile-water mixed solution containing acetate ion, oxalic acid and QuPh(+)-NA was determined to be as high as 0.34, which is more than double the quantum yield obtained by using oxalate salt as an electron donor without acetate ion (0.14). In addition, the turnover number of QuPh(+)-NA reached more than 340. The reaction mechanism and the effect of solvent composition on the photocatalytic H2O2 production were scrutinized by using nanosecond laser flash photolysis. PMID:23631436

Yamada, Yusuke; Nomura, Akifumi; Miyahigashi, Takamitsu; Ohkubo, Kei; Fukuzumi, Shunichi

2013-04-30

288

Formic and acetic acid over the central Amazon region, Brazil 1. Dry season  

SciTech Connect

We have determined the atmospheric concentrations of formic and acetic acid in the gas phase, in aerosols, and in rain during the dry season (July--August 1985) in the Amazonia region of Brazil. At ground level the average concentrations of gas phase formic and acetic acid were 1.6 +- 0.6 and 2.2 +- 1.0 ppb, respectively. The diurnal behavior of both acids at ground level and their vertical distribution in the forest canopy point to the existence of vegetative sources as well as to production by chemical reactions in the atmosphere. Dry deposition of the gaseous acids appears to be a major sink. The concentrations of formic and acetic acid in the gas phase were about 2 orders of magnitude higher than concentrations of the corresponding species in the atmospheric aerosol. About 50--60%/sub 0/ of the aerosol (total) formate and acetate were in the size fraction below 1.0 ..mu..m diameter.

Andreae, M.O.; Talbot, R.W.; Andreae, T.W.; Harriss, R.C.

1988-02-20

289

Amino Acid Transport Systems in Biotechnologically Relevant Bacteria  

Microsoft Academic Search

Besides metabolic pathways and regulatory networks, transport reactions are also pivotal for understanding\\u000a amino acid metabolism and production in bacteria. Apart from substrate uptake, this refers to product (amino\\u000a acid) excretion as well as product re-uptake. Both the mechanistic (kinetic and energetic) as well as structural\\u000a properties of these transport systems are relevant for understanding their significance and for providing

Kay Marin; Reinhard Krämer

290

Barriers to application of genetically modified lactic acid bacteria  

Microsoft Academic Search

To increase the acceptability of food products containing genetically modified microorganisms it is necessary to provide in an early stage to the consumers that the product is safe and that the product provide a clear benefit to the consumer. To comply with the first requirement a systematic approach to analyze the probability that genetically modified lactic acid bacteria will transform

C. T. Verrips; D. J. C. Berg

1996-01-01

291

Lactic acid bacteria in traditional fermented Chinese foods  

Microsoft Academic Search

Food fermentation is a widely practiced and ancient technology in China. Lactic acid bacteria (LAB) are involved in many fermentation processes of Chinese traditional foods, demonstrating their profound effects on improving food quality and food safety. This review article outlines the main types of LAB fermentation as well as their typical fermented foods such as koumiss, suan-tsai, stinky tofu and

Shan-na Liu; Ye Han; Zhi-jiang Zhou

2011-01-01

292

Lactic acid bacteria in a changing legislative environment  

Microsoft Academic Search

The benefits of using lactic acid bacteria in the food chain, both through direct consumption and production of ingredients, are increasingly recognised by the food industry and consumers alike. The regulatory environment surrounding these products is diverse, covering foods and food ingredients, processing aids, feed additives and dietary supplements. On a global basis, there are different approaches taken by the

Jean Feord

2002-01-01

293

New ways of selecting lactic acid bacteria for biotechnological processes  

Microsoft Academic Search

Illustrated by the selection of lactic acid bacteria to be used as biological ensilage agents, new methods are introduced; they are practicable in microtitre plate dimensions by means of an automatic analysing system. According to the test setting, statements can be made on the acidifiability, the inhibition effect on contaminants and the growth under different milieu conditions. Of 126 strains

Joachim Venus; Frank Idler; Christine Albrecht

1992-01-01

294

A useful equation for fermentations of butyric acid bacteria  

Microsoft Academic Search

The usefulness and uses of an equation which would describe the interrelations among the various products and biomass in fermentations of butyric acid bacteria are discussed. Such a fermentation equation is then derived based on the bacterial biochemistry and general biological regularities. The equation obeys all the constraints of the biochemical topology and thermodynamics. The validity of the equation is

Eleftherios Terry Papoutsakis

1983-01-01

295

Equations and calculations for fermentations of butyric acid bacteria  

Microsoft Academic Search

A stoichiometric equation has been derived which describes the interrelations among the various products and biomass in fermentations of butyric acid bacteria. The derivation of the equation is based on an assumed ATP yield, two biological regularities, and the biochemistry of product formation of the fermentations. The equation obeys the constraints imposed on growth and product formation by thermodynamics and

Papoutasakis

1984-01-01

296

Phylogenomic reconstruction of lactic acid bacteria: an update  

Microsoft Academic Search

BACKGROUND: Lactic acid bacteria (LAB) are important in the food industry for the production of fermented food products and in human health as commensals in the gut. However, the phylogenetic relationships among LAB species remain under intensive debate owing to disagreements among different data sets. RESULTS: We performed a phylogenetic analysis of LAB species based on 232 genes from 28

Zhi-Gang Zhang; Zhi-Qiang Ye; Li Yu; Peng Shi

2011-01-01

297

Heme and menaquinone induced electron transport in lactic acid bacteria  

PubMed Central

Background For some lactic acid bacteria higher biomass production as a result of aerobic respiration has been reported upon supplementation with heme and menaquinone. In this report, we have studied a large number of species among lactic acid bacteria for the existence of this trait. Results Heme- (and menaquinone) stimulated aerobic growth was observed for several species and genera of lactic acid bacteria. These include Lactobacillus plantarum, Lactobacillus rhamnosus, Lactobacilllus brevis, Lactobacillus paralimentarius, Streptococcus entericus and Lactococcus garviae. The increased biomass production without further acidification, which are respiration associated traits, are suitable for high-throughput screening as demonstrated by the screening of 8000 Lactococcus lactis insertion mutants. Respiration-negative insertion-mutants were found with noxA, bd-type cytochrome and menaquinol biosynthesis gene-disruptions. Phenotypic screening and in silico genome analysis suggest that respiration can be considered characteristic for certain species. Conclusion We propose that the cyd-genes were present in the common ancestor of lactic acid bacteria, and that multiple gene-loss events best explains the observed distribution of these genes among the species.

Brooijmans, Rob; Smit, Bart; Santos, Filipe; van Riel, Jan; de Vos, Willem M; Hugenholtz, Jeroen

2009-01-01

298

Taxonomy and physiology of probiotic lactic acid bacteria  

Microsoft Academic Search

The current taxonomy of probiotic lactic acid bacteria is reviewed with special focus on the genera Lactobacillus, Bifidobacterium and Enterococcus. The physiology and taxonomic position of species and strains of these genera were investigated by phenotypic and genomic methods. In total, 176 strains, including the type strains, have been included. Phenotypic methods applied were based on biochemical, enzymatical and physiological

Günter Klein; Alexander Pack; Christine Bonaparte; Gerhard Reuter

1998-01-01

299

Genesis of acetate and methane by gut bacteria of nutritionally diverse termites  

SciTech Connect

The evolution of different feeding guilds in termites is paralleled by differences in the activity of their gut microbiota. In wood-feeding termites, carbon dioxide-reducing acetogenic bacteria were found to generally outprocess carbon dioxide-reducing methanogenic bacteria for reductant (presumably hydrogen) generated during microbial fermentation in the hindgut. By contrast, acetogenesis from hydrogen and carbon dioxide was of little significance in fungus-growing and soil-feeding termites, which evolved more methane than their wood- and grass-feeding counterparts. Given the large biomass of termites on the earth and especially in the tropics, these findings should help refine global estimates of carbon dioxide reduction in anoxic habitats and the contribution of termite emissions to atmospheric methane concentrations.

Brauman, A.; Labat, M. (Univ. de Provence, Marseille Cedex (France)); Kane, M.D.; Breznak, J.A. (Michigan State Univ., East Lansing (United States))

1992-09-04

300

Reactive uptake of acetic acid on calcite and nitric acid reacted calcite aerosol in an environmental reaction chamber.  

PubMed

The heterogeneous chemistry of gas-phase acetic acid with CaCO(3)(calcite) aerosol was studied under varying conditions of relative humidity (RH) in an environmental reaction chamber. Infrared spectroscopy showed the loss of gas-phase reactant and the appearance of a gaseous product species, CO(2). The acetic acid is observed to adsorb onto the calcite aerosol through both a fast and a slow uptake channel. While the fast channel is relatively independent of RH, the slow channel exhibits enhanced uptake and reaction as the RH is increased. In additional experiments, the calcite aerosol was exposed to both nitric and acetic acids in the presence of water vapor. The rapid conversion of the particulate carbonate to nitrate and subsequent deliquescence significantly enhances the uptake and reaction of acetic acid. These results suggest a possible mechanism for observed correlations between particulate nitrate and organic acids in the atmosphere. Calcium rich mineral dust may be an important sink for simple organic acids. PMID:18075693

Prince, Amy Preszler; Kleiber, Paul D; Grassian, Vicki H; Young, Mark A

2007-11-21

301

Soil Bacteria Take Up D-Amino Acids, Protect Plants  

NASA Astrophysics Data System (ADS)

Recently, many groups reported D-amino acid uptake by plant roots, raising the question of whether soil D-amino acids represent a source of nitrogen or a source of toxicity. The discussion needs to be placed in the context of competition with rhizosphere bacteria. To provide this context, we followed the concentrations of D- and L-enantiomers of alanine, glutamic acid, aspartic acid, and leucine after they were added to soils in the laboratory. In all cases, the uptake of L-enantiomer began immediately and proceeded rapidly until exhausted. In contrast, the uptake of D-enantiomer required induction: an initial period of inactivity followed by rapid consumption comparable in rate to L-enantiomer. The induced nature of the D activity was confirmed by the addition of rifampicin, an mRNA synthesis inhibitor. Preventing the synthesis of new enzymes abolished soil flora's ability to consume D-amino acids, but not L-amino acids. These results suggest that inducible special racemase enzymes, which can convert D-amino acids back to their native L-forms, are widespread among soil microorganisms. This finding does not rule out the possibility that some plants may out-compete microorganisms and be able to access D-amino acids. It does suggest, however, that rhizosphere bacteria can shield plants from the toxic effect of D-amino acids.

Sun, H. J.; Zhang, G.

2011-12-01

302

Lipidomic Profiling of Saccharomyces cerevisiae and Zygosaccharomyces bailii Reveals Critical Changes in Lipid Composition in Response to Acetic Acid Stress  

PubMed Central

When using microorganisms as cell factories in the production of bio-based fuels or chemicals from lignocellulosic hydrolysate, inhibitory concentrations of acetic acid, released from the biomass, reduce the production rate. The undissociated form of acetic acid enters the cell by passive diffusion across the lipid bilayer, mediating toxic effects inside the cell. In order to elucidate a possible link between lipid composition and acetic acid stress, the present study presents detailed lipidomic profiling of the major lipid species found in the plasma membrane, including glycerophospholipids, sphingolipids and sterols, in Saccharomyces cerevisiae (CEN.PK 113_7D) and Zygosaccharomyces bailii (CBS7555) cultured with acetic acid. Detailed physiological characterization of the response of the two yeasts to acetic acid has also been performed in aerobic batch cultivations using bioreactors. Physiological characterization revealed, as expected, that Z. bailii is more tolerant to acetic acid than S. cerevisiae. Z. bailii grew at acetic acid concentrations above 24 g L?1, while limited growth of S. cerevisiae was observed after 11 h when cultured with only 12 g L?1 acetic acid. Detailed lipidomic profiling using electrospray ionization, multiple-reaction-monitoring mass spectrometry (ESI-MRM-MS) showed remarkable changes in the glycerophospholipid composition of Z. bailii, including an increase in saturated glycerophospholipids and considerable increases in complex sphingolipids in both S. cerevisiae (IPC 6.2×, MIPC 9.1×, M(IP)2C 2.2×) and Z. bailii (IPC 4.9×, MIPC 2.7×, M(IP)2C 2.7×), when cultured with acetic acid. In addition, the basal level of complex sphingolipids was significantly higher in Z. bailii than in S. cerevisiae, further emphasizing the proposed link between lipid saturation, high sphingolipid levels and acetic acid tolerance. The results also suggest that acetic acid tolerance is associated with the ability of a given strain to generate large rearrangements in its lipid profile.

Riezman, Howard; Olsson, Lisbeth; Bettiga, Maurizio

2013-01-01

303

Lipidomic Profiling of Saccharomyces cerevisiae and Zygosaccharomyces bailii Reveals Critical Changes in Lipid Composition in Response to Acetic Acid Stress.  

PubMed

When using microorganisms as cell factories in the production of bio-based fuels or chemicals from lignocellulosic hydrolysate, inhibitory concentrations of acetic acid, released from the biomass, reduce the production rate. The undissociated form of acetic acid enters the cell by passive diffusion across the lipid bilayer, mediating toxic effects inside the cell. In order to elucidate a possible link between lipid composition and acetic acid stress, the present study presents detailed lipidomic profiling of the major lipid species found in the plasma membrane, including glycerophospholipids, sphingolipids and sterols, in Saccharomyces cerevisiae (CEN.PK 113_7D) and Zygosaccharomyces bailii (CBS7555) cultured with acetic acid. Detailed physiological characterization of the response of the two yeasts to acetic acid has also been performed in aerobic batch cultivations using bioreactors. Physiological characterization revealed, as expected, that Z. bailii is more tolerant to acetic acid than S. cerevisiae. Z. bailii grew at acetic acid concentrations above 24 g L(-1), while limited growth of S. cerevisiae was observed after 11 h when cultured with only 12 g L(-1) acetic acid. Detailed lipidomic profiling using electrospray ionization, multiple-reaction-monitoring mass spectrometry (ESI-MRM-MS) showed remarkable changes in the glycerophospholipid composition of Z. bailii, including an increase in saturated glycerophospholipids and considerable increases in complex sphingolipids in both S. cerevisiae (IPC 6.2×, MIPC 9.1×, M(IP)2C 2.2×) and Z. bailii (IPC 4.9×, MIPC 2.7×, M(IP)2C 2.7×), when cultured with acetic acid. In addition, the basal level of complex sphingolipids was significantly higher in Z. bailii than in S. cerevisiae, further emphasizing the proposed link between lipid saturation, high sphingolipid levels and acetic acid tolerance. The results also suggest that acetic acid tolerance is associated with the ability of a given strain to generate large rearrangements in its lipid profile. PMID:24023914

Lindberg, Lina; Santos, Aline Xs; Riezman, Howard; Olsson, Lisbeth; Bettiga, Maurizio

2013-09-04

304

Separation of inorganic anions and cations on titania by use of acetic acid-sodium acetate and bicine-sodium hydroxide buffers  

Microsoft Academic Search

Summary  The ion-exchange retention behavior of titania synthesized in our laboratory was investigated by ion chromatography of inorganic\\u000a anions and cations. Dilute acetic acid-sodium acetate and bicine-sodium hydroxide buffers were used as mobile phases with\\u000a no use of suppresor. We observed that the titania, although poor at separating monovalent anions expcept nitrite ion in this\\u000a experiment, was both an anion and

K. Tani; H. Kubojima

1998-01-01

305

Calibration and intercomparison of acetic acid measurements using proton transfer reaction mass spectrometry (PTR-MS)  

NASA Astrophysics Data System (ADS)

Acetic acid is one of the most abundant organic acids in the ambient atmosphere, with maximum mixing ratios reaching into the tens of parts per billion by volume (ppbv) range. The identities and associated magnitudes of the major sources and sinks for acetic acid are poorly characterized, due in part to the limitation in available measurement techniques. This paper demonstrates that Proton Transfer Reaction Mass Spectrometry (PTR-MS) can reliably quantify acetic acid vapor in ambient air. Three different PTR-MS configurations were calibrated at low ppbv mixing ratios using permeation tubes, which yielded calibration factors between 7.0 and 10.9 normalized counts per second per ppbv (ncps ppbv-1) at a drift tube field strength of 132 townsend (Td). Detection limits ranged from 0.06 to 0.32 ppbv with dwell times of 5 s. These calibration factors showed negligible humidity dependence. Using the experimentally determined calibration factors, PTR-MS measurements of acetic acid during the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) campaign were validated against results obtained using Mist Chambers coupled with Ion Chromatography (MC/IC). An orthogonal least squares linear regression of paired data yielded a slope of 1.14 ± 0.06 (2?), an intercept of 0.049 ± 20 (2?) ppbv, and an R2 of 0.78. The median mixing ratio of acetic acid on Appledore Island, ME during the ICARTT campaign was 0.530 ± 0.025 ppbv with a minimum of 0.075 ± 0.004 ppbv, and a maximum of 3.555 ± 0.171 ppbv.

Haase, K. B.; Keene, W. C.; Pszenny, A. A. P.; Mayne, H. R.; Talbot, R. W.; Sive, B. C.

2012-07-01

306

Calibration and intercomparison of acetic acid measurements using proton transfer reaction mass spectrometry (PTR-MS)  

USGS Publications Warehouse

Acetic acid is one of the most abundant organic acids in the ambient atmosphere, with maximum mixing ratios reaching into the tens of parts per billion by volume (ppbv) range. The identities and associated magnitudes of the major sources and sinks for acetic acid are poorly characterized, due in part to the limitation in available measurement techniques. This paper demonstrates that Proton Transfer Reaction Mass Spectrometry (PTR-MS) can reliably quantify acetic acid vapor in ambient air. Three different PTR-MS configurations were calibrated at low ppbv mixing ratios using permeation tubes, which yielded calibration factors between 7.0 and 10.9 normalized counts per second per ppbv (ncps ppbv?1) at a drift tube field strength of 132 townsend (Td). Detection limits ranged from 0.06 to 0.32 ppbv with dwell times of 5 s. These calibration factors showed negligible humidity dependence. Using the experimentally determined calibration factors, PTR-MS measurements of acetic acid during the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) campaign were validated against results obtained using Mist Chambers coupled with Ion Chromatography (MC/IC). An orthogonal least squares linear regression of paired data yielded a slope of 1.14 ± 0.06 (2?), an intercept of 0.049 ± 20 (2?) ppbv, and an R2 of 0.78. The median mixing ratio of acetic acid on Appledore Island, ME during the ICARTT campaign was 0.530 ± 0.025 ppbv with a minimum of 0.075 ± 0.004 ppbv, and a maximum of 3.555 ± 0.171 ppbv.

Haase, K. B.; Keene, W. C.; Pszenny, A. A. P.; Mayne, H. R.; Talbot, R. W.; Sive, B. C.

2012-01-01

307

Formation of Short-Chain Fatty Acids from H2 and CO2 by a Mixed Culture of Bacteria  

PubMed Central

The biological utilization of CO2 and H2 for the formation of short-chain fatty acids was studied by using a mixed culture of bacteria. Optimization of a medium was carried out in continuous culture to identify limiting factors which controlled growth and production of organic acids. The optimal pH for growth and acid production was 7.0 at 37°C; the maximal cell concentration obtained was 5.9 g of cells per liter (dry weight), and the maximal amount of volatile acids formed was 4.7 g/liter, with acetic acid as the predominant acid. With the optimized medium, it was found that the rate of transfer of hydrogen or carbon dioxide, or both, from gas to liquid was the limiting factor which controlled growth and production of acids.

Goldberg, I.; Cooney, C. L.

1981-01-01

308

Anodic oxidation of 3,4-dihydroxyphenylacetic acid on carbon electrodes in acetic acid solutions.  

PubMed

The electrochemical oxidation of 3,4-dihydroxyphenylacetic acid (DOPAC) on a carbon fiber microelectrode (CF) and a glassy carbon macroelectrode (GC) in glacial acetic acid solutions was investigated using voltammetric techniques. Voltammograms recorded at these electrodes show well-defined single waves or peaks. The proposed mechanism of the anodic oxidation of DOPAC consists of two successive one-electron one-proton steps. The loss of the first electron proceeds irreversibly and determines the overall rate of the electrode process. This stage is accompanied by the generation of an unstable phenoxyl radical in position 4 of the aromatic ring. The second stage of the electrode reaction produces substituted orto-quinone as the final product of the electrode process of DOPAC. DOPAC exhibits more antioxidative power than synthetic BHT and can be useful in food protection against reactive oxygen species. The results presented can help to explain biochemical and antioxidative properties of DOPAC in a living cell and can be useful in determination of this compound in real samples. PMID:20004625

Michalkiewicz, Slawomir; Skorupa, Agata

2009-12-03

309

Importance of secondary sources in the atmospheric budgets of formic and acetic acids  

NASA Astrophysics Data System (ADS)

We present a detailed budget of formic and acetic acids, two of the most abundant trace gases in the atmosphere. Our bottom-up estimate of the global source of formic and acetic acids are ~1200 and ~1400 Gmol yr-1, dominated by photochemical oxidation of biogenic volatile organic compounds, in particular isoprene. Their sinks are dominated by wet and dry deposition. We use the GEOS-Chem chemical transport model to evaluate this budget against an extensive suite of measurements from ground, ship and satellite-based Fourier transform spectrometers, as well as from several aircraft campaigns over North America. The model captures the seasonality of formic and acetic acids well but generally underestimates their concentration, particularly in the Northern midlatitudes. We infer that the source of both carboxylic acids may be up to 50% greater than our estimate and report evidence for a long-lived missing secondary source of carboxylic acids that may be associated with the aging of organic aerosols. Vertical profiles of formic acid in the upper troposphere support a negative temperature dependence of the reaction between formic acid and the hydroxyl radical as suggested by several theoretical studies.

Paulot, F.; Wunch, D.; Crounse, J. D.; Toon, G. C.; Millet, D. B.; Decarlo, P. F.; Vigouroux, C.; Deutscher, N. M.; González Abad, G.; Notholt, J.; Warneke, T.; Hannigan, J. W.; Warneke, C.; de Gouw, J. A.; Dunlea, E. J.; de Mazière, M.; Griffith, D. W. T.; Bernath, P.; Jimenez, J. L.; Wennberg, P. O.

2011-03-01

310

Importance of secondary sources in the atmospheric budgets of formic and acetic acids  

NASA Astrophysics Data System (ADS)

We present a detailed budget of formic and acetic acids, two of the most abundant trace gases in the atmosphere. Our bottom-up estimate of the global source of formic (acetic) acid is ~ 1200 (1400) Gmol/yr, dominated by photochemical oxidation of biogenic volatile organic compounds, in particular isoprene. Their sinks are dominated by wet and dry deposition. We use the GEOS-Chem chemical transport model to evaluate this budget against an extensive suite of measurements from ground, ship and satellite-based Fourier transform spectrometers, as well as from several aircraft campaigns over North America. The model captures the seasonality of formic and acetic acids well but generally underestimates their concentration, particularly in the Northern midlatitudes. We infer that the source of both carboxylic acids may be up to 50% greater than our estimate and report evidence for a long-lived missing secondary source of carboxylic acids that could be associated with the aging of organic aerosols. Vertical profiles of formic acid in the upper troposphere support a negative temperature dependence of the reaction between formic acid and the hydroxyl radical as suggested by several theoretical studies.

Paulot, F.; Wunch, D.; Crounse, J.; Millet, D. B.; Decarlo, P. F.; Vigouroux, C.; Deutscher, N. M.; Gonzalez Abad, G.; Toon, G. C.; Notholt, J.; Warneke, T.; Hannigan, J. W.; Warneke, C.; de Gouw, J. A.; Dunlea, E.; de Maziere, M. M.; Griffith, D. W.; Bernath, P. F.; Jimenez, J. L.; Wennberg, P. O.

2010-12-01

311

Importance of secondary sources in the atmospheric budgets of formic and acetic acids  

NASA Astrophysics Data System (ADS)

We present a detailed budget of formic and acetic acids, two of the most abundant trace gases in the atmosphere. Our bottom-up estimate of the global source of formic and acetic acids are ~1200 and ~1400 Gmol/yr, dominated by photochemical oxidation of biogenic volatile organic compounds, in particular isoprene. Their sinks are dominated by wet and dry deposition. We use the GEOS-Chem chemical transport model to evaluate this budget against an extensive suite of measurements from ground, ship and satellite-based Fourier transform spectrometers, as well as from several aircraft campaigns over North America. The model captures the seasonality of formic and acetic acids well but generally underestimates their concentration, particularly in the Northern midlatitudes. We infer that the source of both carboxylic acids may be up to 50% greater than our estimate and report evidence for a long-lived missing secondary source of carboxylic acids that may be associated with the aging of organic aerosols. Vertical profiles of formic acid in the upper troposphere support a negative temperature dependence of the reaction between formic acid and the hydroxyl radical as suggested by several theoretical studies.

Paulot, F.; Wunch, D.; Crounse, J. D.; Toon, G. C.; Millet, D. B.; Decarlo, P. F.; Vigouroux, C.; Deutscher, N. M.; González Abad, G.; Notholt, J.; Warneke, T.; Hannigan, J. W.; Warneke, C.; de Gouw, J. A.; Dunlea, E. J.; de Mazière, M.; Griffith, D. W. T.; Bernath, P.; Jimenez, J. L.; Wennberg, P. O.

2010-10-01

312

One carbon metabolism in anaerobic bacteria: organic acid and methane production. Final technical report  

SciTech Connect

Organic acids (i.e acetate and butyrate) and methane are respectively important as a chemical commodity and a fuel source for industry. Both of these products can be generated via bacterial fermentation of single carbon compounds (i.e, H/sub 2//CO/sub 2/, HCOOH, CO CH/sub 3/OH) derived from syngas or the pyrolysis of either coals-peats or renewable biomass. This research aims to understand the pathways and regulation of one carbon metabolism in acidogenic and methanogenic bacteria by detailed physiological and biochemical studies. These investigations will characterize and compare formate, methanol, H/sub 2//CO/sub 2/, CO, and acetate metabolism of Methanosarcina barkeri with that of Butyribacterium methylotrophicum. The research will focus on: elucidation of the function of formate dehydrogenase and carbon monoxide dehydrogenase; the catabolic routes and biochemical mechanisms for transformation of single carbon compounds and acetate; and, the regulation of single carbon metabolism during growth on multiple C/sub 1/ substrates or on multicarbon substrates. 8 refs.

Zeikus, J.G.

1985-01-01

313

A temperature-sensitive auxin auxotroph not deficient in indole-3-acetic acid  

Microsoft Academic Search

A temperature-sensitive variant of Hyoscyamus muticus L. expressing a lethal phenotype in both cultured cells and regenerated plants has been shown to be a conditional auxin auxotroph with an absolute requirement for an exogenous auxin at temperatures above 30° C but not at lower temperatures. The requirement was satisfied by indole-3-acetic acid (IAA) and all active auxin analogous tested. Despite

Jiirg Oetiker; Christiane Gebhardt; Patrick J. King

1990-01-01

314

GENE EXPRESSION PATTERNS OF CD-1 DAY-8 EMBRYO CULTURES EXPOSED TO BROMOCHLORO ACETIC ACID  

EPA Science Inventory

Gene expression patterns of CD-1 day-8 embryo cultures exposed to bromochloro acetic acid Edward D. Karoly?*, Judith E. Schmid* and E. Sidney Hunter III* ?Curriculum in Toxicology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina and *Reproductiv...

315

The thermal conductivity and viscosity of acetic acid-water mixtures  

Microsoft Academic Search

The viscosity and thermal conductivity of acetic acid water mixtures were measured over the entire composition range and at temperatures ranging from 293 to 453 K. Viscosity measurements were performed with a high-pressure viscometer and thermal conductivity was measured using a modified transient hot-wire technique. A mercury filled. glass capillary was used as the insulated hot wire in the measurements.

J. G. Bleazard; T. F. Sun; A. S. Teja

1996-01-01

316

Pervaporation of acetic acid\\/water mixtures through silicalite filled polydimethylsiloxane membranes  

Microsoft Academic Search

The preferential pervaporation of acetic acid over water is achieved with silicalite filled polydimethylsiloxane (PDMS) membranes. The effect of silicalite addition is not positive at the feed temperature of 25°C, but improves with increasing feed temperature. At a feed temperature of 45°C, silicalite addition enhances not only the separation factor but also the permeation flux of the pervaporation. This improvement

Shih-Yuan Lu; Chung-Ping Chiu; Hsiang-Yuan Huang

2000-01-01

317

Interactions of indole acetic acid with EGF and FSH in the culture of ovine preantral follicles  

Microsoft Academic Search

The mechanisms that regulate the gradual exit of ovarian follicles from the non-growing, primordial pool are very poorly understood. The objective of this study was to evaluate the effects of adding indole acetic acid (IAA), epidermal growth factor (EGF) and follicle stimulating hormone (FSH) to the media for in vitro culture of ovine ovarian fragments and determine their effects on

Evelyn Rabelo Andrade; Marcelo Marcondes Seneda; Amauri Alcindo Alfieri; João Ademir de Oliveira; Ana Paula Frederico Rodrigues Loureiro Bracarense; José Ricardo Figueiredo; Ricardo Toniolli

2005-01-01

318

Properties of acetic-acid alcohol-containing solutions of chitosan  

Microsoft Academic Search

It was shown that incorporation of ethyl alcohol in acetic-acid solutions of chitosan reduces their turbidity and intrinsic\\u000a viscosity and increases the dynamic viscosity more the higher the concentration of chitosan and the amount of alcohol added.

S. A. Uspenskii; G. A. Vikhoreva; A. N. Sonina; L. S. Gal’braikh

2010-01-01

319

Preparation of carbon fibers from softwood lignin by atmospheric acetic acid pulping  

Microsoft Academic Search

Infusible softwood acetic acid lignin (SAL) was converted to a fusible one as a raw material for carbon fibers by removing the infusible high molecular mass fraction. The resulting low molecular mass fraction (SAL-L) was spun by fusion spinning after thermal treatment to remove volatile materials. Carbon fibers (CFs) were prepared from these fibers by direct carbonization without thermostabilization, leading

S. Kubo; Y. Uraki; Y. Sano

1998-01-01

320

Recovery of lignin and furfural from acetic acid–water–HCl pulping liquors  

Microsoft Academic Search

The feasibility of the HCl–water–acetic acid pulping technology (Acetosolv process) depends on the efficiency of solvent and byproduct recovery. Experimental data and computer simulation calculations are presented to assess these points. The recovery of precipitable, dissolved solids derived from lignin by mixing pulping liquors and water in various proportions was studied. Computer simulation of selected operational strategies enabling the recovery

C Vila; V Santos; J. C Parajó

2003-01-01

321

Effects of Benzyladenine and Naphthalene Acetic Acid on Growth and Camptothecin Accumulation in Camptotheca acuminata Seedlings  

Microsoft Academic Search

The effects of the cytokinin benzyladenine (BA) and the auxin naphthalene acetic acid (NAA) on Camptotheca acuminata Decaisne growth and camptothecin (CPT) accumulation (leaf CPT concentration and total leaf CPT yield) were studied in a hydroponic culture system for three weeks. Increasing BA concentrations from 0 to 3 mg l -1 in growth medium decreased plant height, stem weight, and

Zhanhai Li; Zhijun Liu

2003-01-01

322

Visualization of Early Events in Acetic Acid Denaturation of HIV-1 Protease: A Molecular Dynamics Study  

PubMed Central

Protein denaturation plays a crucial role in cellular processes. In this study, denaturation of HIV-1 Protease (PR) was investigated by all-atom MD simulations in explicit solvent. The PR dimer and monomer were simulated separately in 9 M acetic acid (9 M AcOH) solution and water to study the denaturation process of PR in acetic acid environment. Direct visualization of the denaturation dynamics that is readily available from such simulations has been presented. Our simulations in 9 M AcOH reveal that the PR denaturation begins by separation of dimer into intact monomers and it is only after this separation that the monomer units start denaturing. The denaturation of the monomers is flagged off by the loss of crucial interactions between the ?-helix at C-terminal and surrounding ?-strands. This causes the structure to transit from the equilibrium dynamics to random non-equilibrating dynamics. Residence time calculations indicate that denaturation occurs via direct interaction of the acetic acid molecules with certain regions of the protein in 9 M AcOH. All these observations have helped to decipher a picture of the early events in acetic acid denaturation of PR and have illustrated that the ?-helix and the ?-sheet at the C-terminus of a native and functional PR dimer should maintain both the stability and the function of the enzyme and thus present newer targets for blocking PR function.

Borkar, Aditi Narendra; Rout, Manoj Kumar; Hosur, Ramakrishna V.

2011-01-01

323

Kinetics of hydroxyapatite dissolution in acetic, lactic, and phosphoric acid solutions  

Microsoft Academic Search

Summary The present study was undertaken in an attempt to relate the kinetics of hydroxyapatite dissolution to solution parameters, under experimental conditions relevant to the dental caries process. Thus, the dissolution of hydroxyapatite was studied in acetic, lactic, and dilute phosphoric acid solutions having initial pH values from 4 to 6. Rates of dissolution and the corresponding degree of saturation

H. C. Margolis; E. C. Moreno

1992-01-01

324

Vinegar (20% acetic acid) broadcast application for broadleaf weed control in spring-transplanted onions  

Technology Transfer Automated Retrieval System (TEKTRAN)

Organic weed control research was conducted in southeast Oklahoma to determine the effect of broadcast over-the-top applications of acetic acid (vinegar) on weed control efficacy, crop injury and onion yields. The experiment included 6 weed control treatments (2 application volumes, 2 hand-weeding ...

325

Screening for cervical neoplasia in a developing country utilizing cytology, cervicography and the acetic acid test  

Microsoft Academic Search

Objective: To compare three screening tests for cervical neoplasia. Method: Women (6301) were screened simultaneously with cytology, cervicography and the acetic acid test (AAT). Biopsies were taken from the acetowhite lesions and every fifth seemingly normal cervix. Positive cases (both at screening and histology) were referred for colposcopy. The histology results served as the golden standard. Results: Cytology was positive

H. S. Cronjé; B. F. Cooreman; E. Beyer; R. H. Bam; B. D. Middlecote; P. D. J. Divall

2001-01-01

326

Effect of conjugated linoleic acid immobilization on the hemocompatibility of cellulose acetate membrane  

Microsoft Academic Search

Conjugated linoleic acid (CLA) was covalently immobilized onto cellulose acetate (CA) membranes. The effects of CLA immobilization on the blood coagulation, platelet aggregation, and oxidative stress were evaluated using human blood. The resulting CLA grafting CA membranes were characterized with X-ray photoelectronic spectroscopy (XPS). The complete blood count (CBC) and coagulation time (CT) was evaluated in vitro for the hemocompatibility.

F.-C. Kung; M.-C. Yang

2006-01-01

327

A specific radioimmunoassay for nanogram quantities of the auxin, indole-3-acetic acid  

Microsoft Academic Search

We have developed a specific radioimmunoassay [RIA] for indole-3-acetic acid (IAA) in the 0.2 ng to 12 ng range which, in principle, can be extended to other indole auxins as well. Methods are presented for obtaining suitable antibody, for the RIA procedure, and for measuring IAA in methanolic extracts of plant tissues. Antibody specific for IAA was obtained from rabbits

William Pengelly; Frederick Meins

1977-01-01

328

( S)- ?-methoxyphenyl acetic acid : a new NMR chiral shift reagent for the stereochemical analysis of sulfoxides  

Microsoft Academic Search

The use of (S)-?-methoxyphenyl acetic acid (MPAA) as a general chiral 1H NMR shift reagent for the stereochemical analysis of sulfoxides is demonstrated. Using this methodology, both the enantiomeric purity and the absolute configuration of a wide variety of sulfoxides can be determined.

Herbert L. Holland; Frances M. Brown

1995-01-01

329

Effects of Trimetazidine on Acetic Acid-Induced Colitis in Female Swiss Rats  

Microsoft Academic Search

Induction of colitis by acetic acid (A A) in the rat is widely used experimental model of inflammatory bowel disease (IBD) and ulcerations. AA as an irritant induces colitis involving infiltration of colonic mucosa with neutrophils and increased production of inflammatory mediators, such as hydrogen peroxide (H 2 O 2 ), nitric oxide (NO), myeloperoxidase activity (MPO), and tumor necrosis

Filiz Kuralay; Co?kun Yildiz; Omer Ozutemiz; Huray Islekel; Sezer Caliskan; Basak Bingol; Sermin Ozkal

2003-01-01

330

Extraction of formic and acetic acids from aqueous solution by dynamic headspace-needle trap extraction  

Microsoft Academic Search

A combined method of dynamic headspace-needle trap sample preparation and gas chromatography for the determination of formic and acetic acids in aqueous solution was developed in this study. A needle extraction device coupled with a gas aspirating pump was intended to perform sampling and preconcentration of target compounds from aqueous sample before gas chromatographic analysis. The needle trap extraction (NTE)

Da-Wei Lou; Xinqing Lee; Janusz Pawliszyn

2008-01-01

331

Biosynthesis of Indole3Acetic Acid by the Gall-inducing Fungus Ustilago esculenta  

Microsoft Academic Search

Ustilago esculenta incites the formation of an edible gall and prevents inflorescence and seed production in the aquatic perennial grass, Zizania latifolia. As compared to the healthy tissues, the edible galls had higher amounts of indole-3-acetic acid (IAA), which could be synthesized from the host plant and\\/or the fungal pathogen. In this study we investigated the ability for IAA production

2004-01-01

332

Effects of acetic and butyric acids on solvents production by Clostridium acetobutylicum  

Microsoft Academic Search

The fermentation of glucose by Clostridium acetobutylicum on a synthetic medium is carried out with a conversion of carbon source into solvents of 32 %. The ratio of butanol, acetone and ethanol products is approximately 0.6 - 1.9 - 6. The synthetic medium supplemented with acetic acid at a concentration of 2 g\\/l increases acetone formation and the ratio of

J. R. Martin; H. Petitdemange; J. Ballongue; R. Gay

1983-01-01

333

SALT EFFECT IN LIQUID-LIQUID EQUILIBRIA OF ACETIC ACID-WATER-BENZENE SYSTEM  

Microsoft Academic Search

The effect of sodium sulphate, potassium-sulphate and potassium chloride on the distribution of acetic acid between benzene and water at 35°C is reported. Distribution data of the three quaternaries have been determined at salt saturation and unsaturation in each case, as well as the basic ternary in the absence of salt at that temperature. The simple method of Setschenov is

A. S. NARAYANA; R. NISCHAL; R. PATEL; K. G. PARIKH; R. K. SINGH

1990-01-01

334

The Biological Evaluation of Poly (Vinyl Acetate-Co-Crotonic Acid) Ionomer Hydrogel Coatings.  

National Technical Information Service (NTIS)

Poly(vinyl acetate-co-2%-crotonic acid) 60% sodium ionomer hydrogel was found to be the most thromboresistant hydrogel evaluated in our screening studies. The ionomer hydrogel was graft-coated onto substrate surfaces from an ethanol solution of its monome...

W. F. Beach D. D. Stewart

1980-01-01

335

Improved synthesis of 3-(dialkylaminomethyl)-indole in acetic acid aqueous solution under ultrasound irradiation.  

PubMed

Synthesis of Mannich bases related to gramine via Mannich reaction of secondary amine, formaldehyde and indole or N-methylindole can be carried out in 69-98% yields in acetic acid aqueous solution at 35°C under ultrasound irradiation. Compared with the method using stirring, the present procedure provided several advantages such as milder conditions, shorter reaction time and higher yield. PMID:20646952

Li, Ji-Tai; Sun, Shao-Feng; Sun, Ming-Xuan

2010-06-02

336

Detection of Acetic Acid in wine by means of an electronic nose  

NASA Astrophysics Data System (ADS)

A portable electronic nose (see Fig.1) based on metal oxide semiconductor thin-film sensors has been developed to detect acetic acid present in four types of wines. The wines analyzed are from the same cellar but are made with different varieties of grapes. Data analysis was performed by two pattern recognition methods: principal component analysis (PCA) and Artificial Neural Networks (ANN).

Lozano, Jesús; Álvarez, Fernando; Santos, José Pedro; Horrillo, Carmen

2011-09-01

337

Active specie on vanadium-containing catalysts for the selective oxidation of ethane to acetic acid  

Microsoft Academic Search

Catalytic experiments on pure VPO phases and titania supported VPOx and VOx are presented for the selective oxidation of ethane to acetic acid. The effects of temperature, pressure, contact time and feed conditions are examined. The characterization of catalysts by several methods shows that different specie are present on titania according to the loading V\\/Ti. The correlation with catalytic results

L. Tessier; E. Bordes; M. Gubelmann-Bonneau

1995-01-01

338

Impact of acetic acid concentration of fermented liquid feed on growth performance of piglets  

Microsoft Academic Search

Feeding fermented liquid feed (FLF) to pigs has proven to benefit gastrointestinal health of the animals. However, growth performance data of piglets and growing pigs fed FLF are variable and often a lower feed intake compared to feeding non-FLF or dry feed has been observed. Accumulation of microbial metabolites, namely acetic acid, possibly in combination with low feed pH, has

Nuria Canibe; Anni Øyan Pedersen; Bent Borg Jensen

2010-01-01

339

Acetic Acid Digestion of High-Carbonate Substrates: An Aid to Sorting Aquatic Invertebrate Samples  

Microsoft Academic Search

Soaking high-carbonate sediment samples in 5% acetic acid reduces initial sample volumes; sorting times per unit of original volume and per organism also declined significantly compared with untreated samples. This procedure speeds the sorting of invertebrate samples, especially when similar specific gravities of organisms and substrates render useless the techniques of flotation and elutriation.

Amy Odell Daraghy; Roxanne Conrow; William F. Loftus

1988-01-01

340

Review of Croatian guidelines for use of eicosapentaenoic acid and megestrol acetate in cancer cachexia syndrome  

Microsoft Academic Search

In 2007, Croatian guidelines were developed for the use of eicosapentaenoic acid and megestrol acetate in cancer cachexia syndrome. These guidelines were first published in the Croatian medical journal Lijecnicki vjesnik (Krznaric et al. Lijec Vjesn 2007; 129: 381-6) in Croatian. After nu- merous contacts and discussions with colleagues from the international medical community, we decid- ed to present our

Z. KRZNARIC; A. JURETIC; D. ANZULOVIC

341

The effect of marination on lactic acid bacteria communities in raw broiler fillet strips  

PubMed Central

Marination with marinade containing salt, sugar, and acetic acid is commonly used in Finland to enhance the value of raw broiler meat. In this study, we investigated the effect of marination, marinade components and storage time on composition of bacterial communities in modified atmosphere-packaged (MAP) broiler fillet strips. The communities were characterized using two culture-independent methods: 16S rRNA gene fragment sequencing and terminal restriction fragment length polymorphism. In unmarinated broiler fillet strips, Lactococcus spp. and Carnobacterium spp. predominated at the early storage phase but were partially replaced by Lactobacillus spp. and Leuconostoc spp. when the chilled storage time was extended. In the marinated fillet strips, Lactobacillus spp. and Leuconostoc spp. predominated independent from the storage time. By mixing the different marinade components with broiler meat, we showed that marination changed the community composition and favored Leuconostoc spp. and Lactobacillus spp. by the combined effect of carbohydrates and acetic acid in marinade. Marination increased the maximum level of lactic acid bacteria in broiler meat and enhanced CO2 production and acidification of meat during the chilled storage. Accumulation of CO2 in package head-space due to the enhanced growth of Leuconostoc spp. in marinated meat may lead to bulging of packages, which is a spoilage defect frequently associated with marinated and MAP raw broiler preparations in Finland.

Nieminen, T. T.; Valitalo, H.; Sade, E.; Paloranta, A.; Koskinen, K.; Bjorkroth, J.

2012-01-01

342

The effect of marination on lactic acid bacteria communities in raw broiler fillet strips.  

PubMed

Marination with marinade containing salt, sugar, and acetic acid is commonly used in Finland to enhance the value of raw broiler meat. In this study, we investigated the effect of marination, marinade components and storage time on composition of bacterial communities in modified atmosphere-packaged (MAP) broiler fillet strips. The communities were characterized using two culture-independent methods: 16S rRNA gene fragment sequencing and terminal restriction fragment length polymorphism. In unmarinated broiler fillet strips, Lactococcus spp. and Carnobacterium spp. predominated at the early storage phase but were partially replaced by Lactobacillus spp. and Leuconostoc spp. when the chilled storage time was extended. In the marinated fillet strips, Lactobacillus spp. and Leuconostoc spp. predominated independent from the storage time. By mixing the different marinade components with broiler meat, we showed that marination changed the community composition and favored Leuconostoc spp. and Lactobacillus spp. by the combined effect of carbohydrates and acetic acid in marinade. Marination increased the maximum level of lactic acid bacteria in broiler meat and enhanced CO(2) production and acidification of meat during the chilled storage. Accumulation of CO(2) in package head-space due to the enhanced growth of Leuconostoc spp. in marinated meat may lead to bulging of packages, which is a spoilage defect frequently associated with marinated and MAP raw broiler preparations in Finland. PMID:23087685

Nieminen, T T; Välitalo, H; Säde, E; Paloranta, A; Koskinen, K; Björkroth, J

2012-10-18

343

Degradation of Phthalic Acids by Denitrifying, Mixed Cultures of Bacteria  

PubMed Central

Mixed cultures of bacteria, enriched from aquatic sediments, grew anaerobically on all three isomers of phthalic acid. Each culture grew anaerobically on only one isomer and also grew aerobically on the same isomer. Pure cultures were isolated from the phthalic acid (o-phthalic acid) and isophthalic acid (m-phthalic acid) enrichments that grew aerobically on phthalic and isophthalic acids. Cell suspension experiments indicated that protocatechuate is an intermediate of aerobic catabolism. Pure cultures which grew aerobically on terephthalic acid (p-phthalic acid) could not be isolated from the enrichments, and neither could pure cultures that grew anaerobically on any of the isomers. Cell suspension experiments suggested that separate pathways exist for the aerobic and anaerobic oxidation of phthalic acids. Each enrichment culture used only one phthalic acid isomer under anaerobic conditions, but all isomers were simultaneously adapted for the anaerobic catabolism of benzoate. Cells grown anaerobically on a phthalic acid immediately attacked the isomer under anaerobic conditions, whereas there was a lag before aerobic breakdown occurred, and, for phthalic and terephthalic acids, chloramphenicol stopped aerobic adaptation but had no effect on anaerobic catabolism. This work suggests that phthalic acids are biodegradable in anaerobic environments.

Aftring, R. Paul; Chalker, Bruce E.; Taylor, Barrie F.

1981-01-01

344

The thermal conductivity and viscosity of acetic acid-water mixtures  

NASA Astrophysics Data System (ADS)

The viscosity and thermal conductivity of acetic acid water mixtures were measured over the entire composition range and at temperatures ranging from 293 to 453 K. Viscosity measurements were performed with a high-pressure viscometer and thermal conductivity was measured using a modified transient hot-wire technique. A mercury filled. glass capillary was used as the insulated hot wire in the measurements. The l iscosity data showed unusual trends with respect to composition. At it given temperature. the viscosity was seen to increase with increasing acid concentration, attain a maximum. and then decrease. The thermal conductivity, on the other hand, decreased monotonically with acid concentration. A generalized corresponding-states principle using water and acetic acid as the reference fluids was used to predict both viscosity and thermal conductivity with considerable sucres.

Bleazard, J. G.; Sun, T. F.; Teja, A. S.

1996-01-01

345

Surface Binding of Aflatoxin B1 by Lactic Acid Bacteria  

PubMed Central

Specific lactic acid bacterial strains remove toxins from liquid media by physical binding. The stability of the aflatoxin B1 complexes formed with 12 bacterial strains in both viable and nonviable (heat- or acid-treated) forms was assessed by repetitive aqueous extraction. By the fifth extraction, up to 71% of the total aflatoxin B1 remained bound. Nonviable bacteria retained the highest amount of aflatoxin B1. Lactobacillus rhamnosus strain GG (ATCC 53103) and L. rhamnosus strain LC-705 (DSM 7061) removed aflatoxin B1 from solution most efficiently and were selected for further study. The accessibility of bound aflatoxin B1 to an antibody in an indirect competitive inhibition enzyme-linked immunosorbent assay suggests that surface components of these bacteria are involved in binding. Further evidence is the recovery of around 90% of the bound aflatoxin from the bacteria by solvent extraction. Autoclaving and sonication did not release any detectable aflatoxin B1. Variation in temperature (4 to 37°C) and pH (2 to 10) did not have any significant effect on the amount of aflatoxin B1 released. Binding of aflatoxin B1 appears to be predominantly extracellular for viable and heat-treated bacteria. Acid treatment may permit intracellular binding. In all cases, binding is of a reversible nature, but the stability of the complexes formed depends on strain, treatment, and environmental conditions.

Haskard, Carolyn A.; El-Nezami, Hani S.; Kankaanpaa, Pasi E.; Salminen, Seppo; Ahokas, Jorma T.

2001-01-01

346

Uptake kinetics of acetic acid and acetone on ice surfaces at 190 - 223 K  

NASA Astrophysics Data System (ADS)

Heterogeneous reactions of oxygenated organics may influence the oxidation capacity of the atmosphere with a direct impact on the tropospheric ozone budget. Direct trace gas measurements in the upper troposphere have revealed a high mixing ratio acetic acid (up to 1.9 ppb) and acetone (up to 3 ppb). In the present study we have examined the heterogeneous interactions of acetic acid and acetone with H2O- or D2O-ice (for acetic acid) surfaces using the coated wall flow-tube technique with the detection of gaseous species and reaction products by molecular beam QMS. The experiments were carried in a temperature range between 198 K and 223 K at total pressures ranging from routinely 1 to 5 mbar. The ice surface was prepared by flowing water vapour with nitrogen as a carrier gas through the sliding injector and moving the injector slowly until a thin uniform ice surface was formed. The adsorption-desorption equilibrium of both substances on ice surfaces were measured using initial trace gas concentration between 5 x E+11 and 2 x E+14 molecules cm-3. The calculated adsorption enthalpy was 52(±10) kJ mol-1 for acetic acid and 44(±10) kJ mol-1 for acetone as derived from Langmuir isotherms measured in a temperature range between 190 and 223 K. For desorbing acetic acid molecules we observed first order kinetics with a desorption rate constant of 6?E-2 s-1 at the lowest temperature (i.e.198 K). Using this value together with the assumption of an Arrhenius like temperature dependence for desorption (kdes=Ades exp(-EA/RT)), where Ades ˜ E+13 s-1 we obtain EA,des ˜ 60 kJ mol-1. At slightly higher temperatures (203 K, 208 K) an increasing deviation from first order kinetic behavior is observed. At the same time the desorption peak is broadening and shifted to longer residence times. To estimate the residence time, the extent of dissociation and thermodynamic data of the intermediate adsorbed acetic acid molecules we performed proton exchange experiments using a D2O-ice surface. A measured proton exchange probability for acetic acid of 0.01 at 208 K leads to the assumption of a selected orientation of the molecules which dissociate on the surface. With decreasing temperature we also observe an increasing time shift (?) between the adsorption and desorption signal. At 208 K we measured ? = 3 s. The observed temperature dependence of time shifts corresponds to an activation energy for desorption of 56(±10) kJ mol-1, in good agreement with direct desorption measurements.

Terziyski, A.; Behr, P.; Scharfenort, U.; Demiral, K.; Zellner, R.

2003-04-01

347

Interaction of ethylene with indole-3-acetic acid in regulation of rooting in pea cuttings  

Microsoft Academic Search

Cuttings of pea (Pisum sativum L. cv Marma) were treated with 1-aminocyclopropane-l-carboxylic acid (ACC). This treatment caused increased ethylene production and reduction of root formation. The effect of 0.1 mM ACC on the level of endogenous indole-3-acetic acid (IAA) in the rooting zone and in the shoot apex was analyzed by gas chromatography-single ion monitoring mass spectrometry or by high

A.-C. Nordstrom; L. Eliasson

1993-01-01

348

2,2,3-trimethylbutane and differently-branched hydrocarbons through hydrogenation of trialkyl acetic acid  

Microsoft Academic Search

This report described a method of producing Triptan (2,2,3-trimethylbutane). The starting material was diisopropyl ketone (Isobutyron). It was transformed into dimethylisopropyl acetic acid by first chlorinating the starting material and then treating it with a water-free alkali (sodium hydroxide) in a benzene solution containing a small amount of sodium metal to tie up any remaining water. The acid crystallized out

Bueren

1944-01-01

349

Energetics of Sheep Concerned with the Utilization of Acetic Acid1'2  

Microsoft Academic Search

The efficiency of utilization for growth-fattening, of the energy of diets resulting in high (5.4:1) and low (3.1:1) ratios of acetic acid to propionic acid in the ruminai ingesta was determined in 24 intact male and 24 female sheep by means of a slaughter-analysis experiment. To establish the chemical composition and energy value of the body at the beginning of

L. S. BULL; J. T. REID; E. JOHNSON

2010-01-01

350

Modeling of yeast Brettanomyces bruxellensis growth at different acetic acid concentrations under aerobic and anaerobic conditions  

Microsoft Academic Search

Glucose utilization by Brettanomyces bruxellensis at different acetic acid concentrations under aerobic and anaerobic conditions was investigated. The presence of the organic\\u000a acid disturbs the growth and fermentative activity of the yeast when its concentration exceeds 2 g l?1. A mathematical model is proposed for the kinetic behavior analysis of yeast growing in batch culture. A Matlab algorithm\\u000a was used for estimation

Garcia Alvarado Yahara; Mendez Ancona Javier; Mata Jimenez Marco Tulio; Gómez Rodriguez Javier; Aguilar Uscanga Maria Guadalupe

2007-01-01

351

A Study of Polydimethylsiloxane\\/Aromatic Polyamide Laminated Membranes for Separation of Acetic Acid\\/Water Mixtures by Pervaporation Process  

Microsoft Academic Search

Separation of acetic acid\\/water mixtures by pervaporation was attempted over a range of compositions using polydimethylsiloxane (PDMS), aromatic polyamide (PA), and laminated polydimethylsiloxane-aromatic polyamide membranes. PDMS membranes are hydrophobic and acetic acid selective, whereas PA membranes are hydrophilic and water selective. When PDMS and PA membranes were laminated, with PDMS on the top side and in contact with the feed,

SHENGZHI DENG; S. SOURIRAJAN; T. MATSUURA

1994-01-01

352

Microbial process for the preparation of acetic acid as well as solvent for its extraction from the fermentation broth  

DOEpatents

A modified water-immiscible solvent useful in the extraction of acetic acid from aqueous streams is a substantially pure mixture of isomers of highly branched di-alkyl amines. This solvent is substantially devoid of mono-alkyl amines and alcohols. Solvent mixtures formed of such a modified solvent with a desired cosolvent, preferably a low boiling hydrocarbon which forms an azeotrope with water are useful in the extraction of acetic acid from aqueous gaseous streams. An anaerobic microbial fermentation process for the production of acetic acid employs such solvents, under conditions which limit amide formation by the solvent and thus increase the efficiency of acetic acid recovery. Methods for the direct extraction of acetic acid and the extractive fermentation of acetic acid also employ the modified solvents and increase efficiency of acetic acid production. Such increases in efficiency are also obtained where the energy source for the microbial fermentation contains carbon dioxide and the method includes a carbon dioxide stripping step prior to extraction of acetic acid in solvent.

Gaddy, James L. (Fayetteville, AR); Clausen, Edgar C. (Fayetteville, AR); Ko, Ching-Whan (Fayetteville, AR); Wade, Leslie E. (Corpus Christi, TX); Wikstrom, Carl V. (Fayetteville, AR)

2002-01-01

353

Acetic acid production of Vibrio halioticoli from alginate: a possible role for establishment of abalone– V. halioticoli association  

Microsoft Academic Search

Acetic acid, which is converted from cellulose by means of the metabolism of their gut microbes, is an important oxidizable energy source and precursors of anabolism in ruminant animals and xylophagus insects. However, acetic acid production from algal polysaccharides by means of the metabolism of gut microbes of marine herbivorous invertebrates is not well studied. Abundance of Vibrio halioticoli, which

Tomoo Sawabe; Naka Setoguchi; Sahoko Inoue; Reiji Tanaka; Masashi Ootsubo; Mamoru Yoshimizu; Yoshio Ezura

2003-01-01

354

The use of static and dynamic physical property measurements to infer structural properties of associated liquids: Acetic acid-water  

Microsoft Academic Search

The anomalies which occur in most static and dynamic physical property measurements on solutions of water in acetic acid can be used with critical analysis to infer associative molecular structures. The anomalies indicate significant structural changes. Proton magnetic resonance chemical shifts for acetic acid-water solutions show a significant structural change occurring in the region of equal molar concentration. Literature values

Robert W. Sims; M. Robert Willicott III; R. R. Inners

1979-01-01

355

The use of static and dynamic physical property measurements to infer structural properties of associated liquids: Acetic acid–water  

Microsoft Academic Search

The anomalies which occur in most static and dynamic physical property measurements on solutions of water in acetic acid can be used with critical analysis to infer associative molecular structures. The anomalies indicate significant structural changes. Proton magnetic resonance chemical shifts for acetic acid–water solutions show a significant structural change occurring in the region of equal molar concentration. Literature values

Robert W. Sims; M. Robert Willicott III; R. R. Inners

1979-01-01

356

Analysis of vaginal acetic acid in patients undergoing treatment for bacterial vaginosis.  

PubMed

A "gold standard" method for the diagnosis of bacterial vaginosis (BV) is lacking. The clinical criteria described by the Amsel technique are subjective and difficult to quantify. Alternatively, the reading of Gram-stained vaginal smears by scoring techniques such as those that use the Nugent or Hay-Ison scoring systems is again subjective, requires expert personnel to perform the reading, and is infrequently used clinically. Recently, a new diagnostic device, the Osmetech Microbial Analyzer--Bacterial Vaginosis (OMA-BV), which determines a patient's BV status on the basis of measurement of the amount of acetic acid present in a vaginal swab specimen, was approved by the Food and Drug Administration. The present study uses the conducting polymer gas-sensing technology of OMA-BV to measure the concentration of acetic acid in the headspace above vaginal swab specimens from patients undergoing treatment for BV with metronidazole. In 97.8% of the cases the level of acetic acid detected fell sharply during the treatment period, crossing from above to below the diagnostic threshold of 900 ppm. The diagnosis obtained on the basis of the level of vaginal acetic acid was compared with the diagnoses obtained by use of the Amsel criteria and the Nugent scoring system both at the time of initial entry into the study and at the repeat samplings on days 7 and 14. The results obtained with OMA-BV showed overall agreements compared with the results of the Amsel and Nugent tests of 98 and 94%, respectively, for the 34 patients monitored through the treatment process. This provides further evidence that the measurement of vaginal acetic acid by headspace analysis with conducting polymer sensors is a valid alternative to present tests for the diagnosis of BV. PMID:15528711

Chaudry, Amjad N; Travers, Paul J; Yuenger, Jeffrey; Colletta, Lorraine; Evans, Phillip; Zenilman, Jonathan M; Tummon, Andrew

2004-11-01

357

Analysis of Vaginal Acetic Acid in Patients Undergoing Treatment for Bacterial Vaginosis  

PubMed Central

A “gold standard” method for the diagnosis of bacterial vaginosis (BV) is lacking. The clinical criteria described by the Amsel technique are subjective and difficult to quantify. Alternatively, the reading of Gram-stained vaginal smears by scoring techniques such as those that use the Nugent or Hay-Ison scoring systems is again subjective, requires expert personnel to perform the reading, and is infrequently used clinically. Recently, a new diagnostic device, the Osmetech Microbial Analyzer—Bacterial Vaginosis (OMA-BV), which determines a patient's BV status on the basis of measurement of the amount of acetic acid present in a vaginal swab specimen, was approved by the Food and Drug Administration. The present study uses the conducting polymer gas-sensing technology of OMA-BV to measure the concentration of acetic acid in the headspace above vaginal swab specimens from patients undergoing treatment for BV with metronidazole. In 97.8% of the cases the level of acetic acid detected fell sharply during the treatment period, crossing from above to below the diagnostic threshold of 900 ppm. The diagnosis obtained on the basis of the level of vaginal acetic acid was compared with the diagnoses obtained by use of the Amsel criteria and the Nugent scoring system both at the time of initial entry into the study and at the repeat samplings on days 7 and 14. The results obtained with OMA-BV showed overall agreements compared with the results of the Amsel and Nugent tests of 98 and 94%, respectively, for the 34 patients monitored through the treatment process. This provides further evidence that the measurement of vaginal acetic acid by headspace analysis with conducting polymer sensors is a valid alternative to present tests for the diagnosis of BV.

Chaudry, Amjad N.; Travers, Paul J.; Yuenger, Jeffrey; Colletta, Lorraine; Evans, Phillip; Zenilman, Jonathan M.; Tummon, Andrew

2004-01-01

358

The Formation of Acetic Acid (CH3COOH) in Interstellar Ice Analogs  

NASA Astrophysics Data System (ADS)

Binary ice mixtures of methane (CH4) and carbon dioxide (CO 2) ices were irradiated at 12 K with energetic electrons to mimic the energy transfer processes that occur in the track of the trajectories of MeV cosmic-ray particles. The formation of trans-acetic acid (CH3COOH) was established through the appearance of new bands in the infrared spectrum at 1780, 1195, 1160, 1051, and 957 cm-1 two dimeric forms of acetic acid were assigned via absorptions at 1757 and 1723 cm-1 . During warm-up of the ice sample, the mass spectrometer recorded peaks of m/z values of 60 and 45 associated with the C2H 4O2+ and COOH+ molecular ion and fragment, respectively. The kinetic fits of the column densities of the acetic acid molecule suggest that the initial step of the formation process appears to be the cleavage of a carbon-hydrogen bond from methane to generate the methyl radical plus atomic hydrogen. The hydrogen atom holds excess kinetic energy allowing it to overcome entrance barriers required to add to a carbon dioxide molecule, generating the carboxyl radical (HOCO). This radical can recombine with the methyl radical to form acetic acid molecule. Similar processes are expected to form acetic acid in the interstellar medium, thus providing alternatives to gas-phase processes for the generation of complex chemical species whose fractional abundances compared to molecular hydrogen of typically a few×10-9 cannot be accounted for by solely gas-phase chemistry.

Bennett, Chris J.; Kaiser, Ralf I.

2007-05-01

359

Analysis of the stable carbon isotope composition of formic and acetic acids.  

PubMed

Formic and acetic acids are ubiquitous in the environment and in many biological processes. Analysis of the stable carbon isotope composition (?(13)C) of formic and acetic acids is important to understanding their biogeochemical cycles. However, it has been faced with poor accuracy and high detection limits due to their low carbon number, high hydrophilicity, and semi-volatility. Here we developed an analytical technique by needle trap and gas chromatography-isotope ratio mass spectrometry (GC-IRMS). The organic acids in aqueous solution were extracted using a NeedlEx needle through purge-and-trap and were analyzed by GC-IRMS for ?(13)C. The procedures incur no isotope fractionation. Defined as the point at which the mean ?(13)C is statistically the same as the given value and the analytical error starts rising, the method's detection limits are 200 and 100 mg/L for formic and acetic acids, respectively, with an uncertainty of approximately 0.5‰ in direct extraction and analysis. They were lowered to 1 mg/L with precision of 0.9‰ after samples were subjected to preconcentration. The method was successfully applied to natural samples as diverse as precipitation, vinegars, ant plasma, and vehicle exhaust, which vary considerably in concentration and matrix of the organic acids. It is applicable to the organic acids in not only aqueous solution but also gaseous phase. PMID:23395975

Lee, Xinqing; Zhang, Like; Huang, Daikuan; An, Ning; Yang, Fang; Jiang, Wei; Fang, Bin

2013-02-08

360

A nitrilo-tri-acetic-acid/acetic acid route for the deposition of epitaxial cerium oxide films as high temperature superconductor buffer layers  

SciTech Connect

A water based cerium oxide precursor solution using nitrilo-tri-acetic-acid (NTA) and acetic acid as complexing agents is described in detail. This precursor solution is used for the deposition of epitaxial CeO{sub 2} layers on Ni-5at%W substrates by dip-coating. The influence of the complexation behavior on the formation of transparent, homogeneous solutions and gels has been studied. It is found that ethylenediamine plays an important role in the gelification. The growth conditions for cerium oxide films were Ar-5% gas processing atmosphere, a solution concentration level of 0.25 M, a dwell time of 60 min at 900 {sup o}C and 5-30 min at 1050 {sup o}C. X-ray diffraction (XRD), scanning electron microscope (SEM), atomic force microscopy (AFM), pole figures and spectroscopic ellipsometry were used to characterize the CeO{sub 2} films with different thicknesses. Attenuated total reflection-Fourier transform infrared (ATR-FTIR) was used to determine the carbon residue level in the surface of the cerium oxide film, which was found to be lower than 0.01%. Textured films with a thickness of 50 nm were obtained. - Graphical abstract: Study of the complexation and hydrolysis behavior of Ce{sup 4+} ions in the presence of nitrilo-tri-acetic acid and the subsequent development of an aqueous chemical solution deposition route suited for the processing of textured CeO{sub 2} buffer layers on Ni-W tapes.

Thuy, T.T.; Lommens, P.; Narayanan, V.; Van de Velde, N.; De Buysser, K.; Herman, G.G.; Cloet, V. [Department of Inorganic and Physical Chemistry, Ghent University, Krijgslaan 281 - S3, 9000 Gent (Belgium); Van Driessche, I., E-mail: Isabel.Vandriessche@UGent.b [Department of Inorganic and Physical Chemistry, Ghent University, Krijgslaan 281 - S3, 9000 Gent (Belgium)

2010-09-15

361

Cellulose esterification with fatty acids and acetic anhydride in lithium chloride\\/ N,N -dimethylacetamide medium  

Microsoft Academic Search

Homogeneous esterification of cellulose with saturated fatty acids (n-octanoic to n-octadecanoic) was accomplished with acetic anhydride co-reactant in lithium chloride\\/N,N-dimethylacetamide (LiCl\\/DMAc) medium. Cellulose mixed triesters (CMT) were obtained after 5 h at 130°C with an average of\\u000a 2.2 acetyl groups and 0.8 fatty substituents per anhydroglucose unit. A mixed acetic-fatty anhydride, formed in situ, accounts for the grafting of the

C. Vaca-Garcia; S. Thiebaud; M. E. Borredon; G. Gozzelino

1998-01-01

362

Kinetics of the catalytic destruction of acetic acid in p-XYLENE undergoing oxidation  

SciTech Connect

The oxidation of p-xylene in acetic acid medium was studied in the presence of a cobalt-manganese bromide catalyst at 145/sup 0/C and 1.82 /SUP ./ 10/sup 6/ Pa. It was established that the introduction of 5-10% manganese into a cobalt bromide catalyst leads to an acceleration of the oxidation of p-xylene and simultaneously to a decrease in the proportion of decarboxylation and burnout of the solvent. The observed kinetic principles are explained by peculiarities of the thermolysis of cobalt (III) and manganese (III) acetates, as well as by the formation of cobalt-manganese bromide complexes possessing increased activity.

Kenigsberg, T.P.; Ariko, N.G.; Mitskevich, N.I.; Nazimok, V.F.

1986-06-01

363

Ability of Thermophilic Lactic Acid Bacteria To Produce Aroma Compounds from Amino Acids  

Microsoft Academic Search

Although a large number of key odorants of Swiss-type cheese result from amino acid catabolism, the amino acid catabolic pathways in the bacteria present in these cheeses are not well known. In this study, we compared the in vitro abilities of Lactobacillus delbrueckii subsp. lactis, Lactobacillus helveticus, and Streptococcus ther- mophilus to produce aroma compounds from three amino acids, leucine,

Sandra Helinck; Dominique Le Bars; Daniel Moreau; Mireille Yvon

2004-01-01

364

Cell membrane damage induced by phenolic acids on wine lactic acid bacteria  

Microsoft Academic Search

The aim of this work was to investigate the effect of phenolic acids on cell membrane permeability of lactic acid bacteria from wine. Several phenolic acids were tested for their effects on the cell membrane of Oenococcus oeni and Lactobacillus hilgardii by measuring potassium and phosphate efflux, proton influx and by assessing culture viability employing a fluorescence technique based on

F. M. Campos; J. A. Couto; A. R. Figueiredo; I. V. Tóth; A. O. S. S. Rangel; T. A. Hogg

2009-01-01

365

Purification Techniques of Bacteriocins from Lactic Acid Bacteria and Other Gram-Positive Bacteria  

Microsoft Academic Search

\\u000a The search for new antimicrobial peptides produced by lactic acid ­bacteria and other Gram-positive microorganisms has become\\u000a an interesting field of research in the past decades. The fact that bacteriocins are active against numerous foodborne and\\u000a human pathogens, are produced by generally regarded as safe (GRAS) microorganisms, and are readily degraded by proteolytic\\u000a host systems makes them attractive candidates for

Lucila Saavedra; Fernando Sesma

2011-01-01

366

Extraction and sorption of acetic acid at pH above pK{sub a} to form calcium magnesium acetate  

SciTech Connect

The use of rock salt for deicing roads has many negative effects on automobiles, highway systems, and the environment. Calcium magnesium acetate, hence-forth denoted CMA, has been identified as a more desirable, environmentally benign solid deicer for high-ways, airport runaways, and similar applications. CMA is also of interest as an additive for scavenging sulfur in combustion processes so as to reduce emissions of sulfur oxides and as a catalyst for coal gasification. Different extractants (trioctylphosphine oxide and secondary, tertiary, and quaternary amines) and solid sorbents (tertiary and quaternary amines) were investigated as agents for recovery of acetic acid as part of a process for production of CMA from fermentation acetic acid. The pH and temperature dependencies for uptake of acetic acid by these extractants and sorbents were measured, along with the degrees of regeneration by aqueous suspensions of slaked dolomitic lime. These results enable identification of agents having optimal basicity. Among the extractants, the secondary amine Amberlite LA-2 gave the best combined performance for extraction and regeneration. Among the sorbents, a tertiary amine, Amberlite IRA-35, gave the best performance. Trioctylphosphine oxide does not maintain capacity in the pH range (about 6) most attractive for acetic acid fermentation. Slurred crushed dolomite is not sufficiently basic to accomplish regeneration.

Reisinger, H.; King, C.J. [Lawrence Berkeley Lab., CA (United States)

1995-03-01

367

Acetate production from whey lactose using co-immobilized cells of homolactic and homoacetic bacteria in a fibrous-bed bioreactor.  

PubMed

Acetate was produced from whey lactose in batch and fed-batch fermentations using co-immobilized cells of Clostridium formicoaceticum and Lactococcus lactis. The cells were immobilized in a spirally wound fibrous sheet packed in a 0.45-L column reactor, with liquid circulated through a 5-L stirred-tank fermentor. Industrial-grade nitrogen sources, including corn steep liquor, casein hydrolysate, and yeast hydrolysate, were studied as inexpensive nutrient supplements to whey permeate and acid whey. Supplementation with either 2.5% (v/v) corn steep liquor or 1.5 g/L casein hydrolysate was adequate for the cocultured fermentation. The overall acetic acid yield from lactose was 0.9 g/g, and the productivity was 0.25 g/(L h). Both lactate and acetate at high concentrations inhibited the homoacetic fermentation. To overcome these inhibitions, fed-batch fermentations were used to keep lactate concentration low and to adapt cells to high-concentration acetate. The final acetate concentration obtained in the fed-batch fermentation was 75 g/L, which was the highest acetate concentration ever produced by C. formicoaceticum. Even at this high acetate concentration, the overall productivity was 0.18 g/(L h) based on the total medium volume and 1.23 g/(L h) based on the fibrous-bed reactor volume. The cells isolated from the fibrous-bed bioreactor at the end of this study were more tolerant to acetic acid than the original culture used to seed the bioreactor, indicating that adaptation and natural selection of acetate-tolerant strains occurred. This cocultured fermentation process could be used to produce a low-cost acetate deicer from whey permeate and acid whey. PMID:10099456

Huang, Y; Yang, S T

1998-11-20

368

Increases in jasmonic acid caused by indole-3-acetic acid and auxin herbicides in cleavers (Galium aparine).  

PubMed

The effects of indole-3-acetic acid and auxin herbicides on endogenous jasmonic acid (JA) concentrations were studied in relation to changes in ethylene and abscisic acid (ABA) levels in cleavers (Galium aparine). When plants were root-treated with increasing concentrations of indole-3-acetic acid (IAA), ethylene biosynthesis was stimulated in response to the accumulation of endogenous IAA in the shoot tissue. Within 25h of treatment, stimulated ethylene formation was accompanied by increases in immunoreactive concentrations of JA and ABA, which reached maxima of 4.5-fold and 26-fold of the control, respectively, at 100 microM of applied IAA. Corresponding effects were obtained using synthetic auxins and when the ethylene-releasing compound ethephon was applied exogenously. This represents the first report, to our knowledge, of an auxin-mediated increase in JA levels. The increase in JA may be triggered by ethylene. PMID:15310070

Grossmann, Klaus; Rosenthal, Cindy; Kwiatkowski, Jacek

2004-07-01

369

Expanded scope of synthetic bacteriochlorins via improved acid catalysis conditions and diverse dihydrodipyrrin-acetals.  

PubMed

Bacteriochlorins are attractive candidates for a wide variety of photochemical studies owing to their strong absorption in the near-infrared spectral region. The prior acid-catalysis conditions [BF(3) x O(Et)(2) in CH(3)CN at room temperature] for self-condensation of a dihydrodipyrrin-acetal (bearing a geminal dimethyl group in the pyrroline ring) typically afforded a mixture of three macrocycles: the expected 5-methoxybacteriochlorin (MeOBC-type), a 5-unsubstituted bacteriochlorin (HBC-type), and a free base B,D-tetradehydrocorrin (TDC-type). Here, a broad survey of >20 acids identified four promising acid catalysis conditions of which TMSOTf/2,6-di-tert-butylpyridine in CH(2)Cl(2) at room temperature was most attractive owing to formation of the 5-methoxybacteriochlorin as the sole macrocycle regardless of the pyrrolic substituents in the dihydrodipyrrin-acetal (electron-withdrawing, electron-donating, or no substituent). Eleven new dihydrodipyrrin-acetals were prepared following standard routes. Application of the new acid catalysis conditions has afforded diverse bacteriochlorins (e.g., bearing alkyl/ester, aryl/ester, diester, and no substituents) in a few days from commercially available starting materials. Consideration of the synthetic steps and yields for formation of the dihydrodipyrrin-acetal and bacteriochlorin underpins evaluation of synthetic plans for early installation of bacteriochlorin substituents via the dihydrodipyrrin-acetal versus late installation via derivatization of beta-bromobacteriochlorins. Treatment of the 5-methoxybacteriochlorins with NBS gave regioselective 15-bromination when no pyrrolic substituents were present or when each pyrrole contained two substituents; on the other hand, the presence of a beta-ethoxycarbonyl group caused loss of regioselectivity. The 15 new bacteriochlorins prepared herein exhibit a long-wavelength absorption band in the range 707-759 nm, providing tunable access to the near-infrared region. Taken together, this study expands the scope of available bacteriochlorins for fundamental studies and diverse applications. PMID:20088604

Krayer, Michael; Ptaszek, Marcin; Kim, Han-Je; Meneely, Kelly R; Fan, Dazhong; Secor, Kristen; Lindsey, Jonathan S

2010-02-19

370

Oxygen-dependent catabolism of indole-3-acetic acid in Bradyrhizobium japonicum.  

PubMed Central

Some strains of Bradyrhizobium japonicum have the ability to catabolize indole-3-acetic acid (IAA). Examination of this catabolism in strain 110 by in vivo experiments has revealed an enzymatic activity catalyzing the degradation of IAA and 5-hydroxy-indole-3-acetic acid. The activity requires addition of the substrates for induction and is oxygen dependent. The highest activity is obtained when the concentration of inducer is 0.2 mM. Spectrophotometric data are consistent with the suggestion that the indole ring is broken during degradation of IAA. We hypothesize that the enzyme catalyzes an oxygen-consuming opening of the indole ring analogous to the one catalyzed by tryptophan 2,3-dioxygenase. The pattern of metabolite usage by known tryptophan-auxotrophic mutants and studies of metabolites by high-performance liquid chromatography indicate that anthranilic acid is a terminal degradation product in the proposed pathway.

Egebo, L A; Nielsen, S V; Jochimsen, B U

1991-01-01

371

Chemiluminometric determination of the pesticide 3-indolyl acetic acid by a flow injection analysis assembly.  

PubMed

A new method is proposed for the chemiluminescent determination of the pesticide 3-indolyl acetic acid by means of an flow injection analysis system. The chemiluminescence emission is obtained by oxidation of the analyte with Ce (IV) in nitric acid and presence of beta-cyclodextrine. The continuous-flow method allows the determination of 159samplesh(-1) of 3-indolyl acetic acid in an interval of concentrations over the range 0.5-15.0mgl(-1). The limit of detection was 0.1mugl(-1) and the R.S.D. (n, 17) at 2.0mgl(-1) of the pesticide level was 2.7%. The method was applied to water samples. PMID:19071306

Neves, A I Pimentel; Albert-García, J R; Calatayud, J Martínez

2006-05-24

372

Genomic Expression Program Involving the Haa1p-Regulon in Saccharomyces cerevisiae Response to Acetic Acid  

PubMed Central

Abstract The alterations occurring in yeast genomic expression during early response to acetic acid and the involvement of the transcription factor Haa1p in this transcriptional reprogramming are described in this study. Haa1p was found to regulate, directly or indirectly, the transcription of approximately 80% of the acetic acid-activated genes, suggesting that Haa1p is the main player in the control of yeast response to this weak acid. The genes identified in this work as being activated in response to acetic acid in a Haa1p-dependent manner include protein kinases, multidrug resistance transporters, proteins involved in lipid metabolism, in nucleic acid processing, and proteins of unknown function. Among these genes, the expression of SAP30 and HRK1 provided the strongest protective effect toward acetic acid. SAP30 encode a subunit of a histone deacetylase complex and HRK1 encode a protein kinase belonging to a family of protein kinases dedicated to the regulation of plasma membrane transporters activity. The deletion of the HRK1 gene was found to lead to the increase of the accumulation of labeled acetic acid into acid-stressed yeast cells, suggesting that the role of both HAA1 and HRK1 in providing protection against acetic acid is, at least partially, related with their involvement in the reduction of intracellular acetate concentration.

Becker, Jorg D.; Sa-Correia, Isabel

2010-01-01

373

Observation of SERS of picolinic acid and nicotinic acid using cellulose acetate films doped with Ag fine particles  

NASA Astrophysics Data System (ADS)

Surface enhanced Raman (SER) spectra of picolinic acid and nicotinic acid were observed using cellulose acetate (CA) films doped with Ag fine particles. The spectra obtained match those reported for silver colloids though some differences in SER band intensity were observed. The ease of preparation and handling of the CA film method renders it more useful than the colloid method for the observation of SER spectra.

Imai, Yoshika; Kurokawa, Yoichi; Hara, Masaru; Fukushima, Michiko

1997-10-01

374

A solvent extraction approach to recover acetic acid from mixed waste acids produced during semiconductor wafer process  

Microsoft Academic Search

Recovery of acetic acid (HAc) from the waste etching solution discharged from silicon wafer manufacturing process has been attempted by using solvent extraction process. For this purpose 2-ethylhexyl alcohol (EHA) was used as organic solvent. In the pre-treatment stage >99% silicon and hydrofluoric acid was removed from the solution by precipitation. The synthesized product, Na2SiF6 having 98.2% purity was considered

Chang-Hoon Shin; Ju-Yup Kim; Jun-Young Kim; Hyun-Sang Kim; Hyang-Sook Lee; Debasish Mohapatra; Jae-Woo Ahn; Jong-Gwan Ahn; Wookeun Bae

2009-01-01

375

Carriers for abscisic acid and indole-3-acetic acid in primary roots: their regional localisation and thermodynamic driving forces  

Microsoft Academic Search

A carrier for the uptake of abscisic acid (ABA) is present in the tips and elongating zones of primary roots of both leguminous (runner bean, French bean, pea) and non-leguminous (sunflower, maize) seedlings. No ABA carrier was present in more mature root regions. For indole-3-acetic acid both carrier-mediated uptake and a 2,3,5-triiodobenzoate-sensitive efflux component are present in growing and in

M. C. Astle; P. H. Rubery

1983-01-01

376

Lateral root formation in rice ( Oryza Sativa L.): differential effects of indole-3-acetic acid and indole-3-butyric acid  

Microsoft Academic Search

Comparative effects of indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) on lateral root (LR) formation were studied using 2-day-old seedlings of IR8 rice (Oryza sativa L.). Results showed that IBA at all concentrations (0.8–500 nmol\\/L) increased the number of LRs in the seminal root. However exogenous IAA, failed to increase the number of LRs. On the other hand, both IBA

Shucai Wang; Shin Taketa; Masahiko Ichii; Langlai Xu; Kai Xia; Xie Zhou

2003-01-01

377

Azospirillum brasilense Produces the Auxin-Like Phenylacetic Acid by Using the Key Enzyme for Indole3Acetic Acid Biosynthesis  

Microsoft Academic Search

Received 23 August 2004\\/Accepted 28 October 2004 An antimicrobial compound was isolated from Azospirillum brasilense culture extracts by high-performance liquid chromatography and further identified by gas chromatography-mass spectrometry as the auxin-like molecule, phenylacetic acid (PAA). PAA synthesis was found to be mediated by the indole-3-pyruvate decar- boxylase, previously identified as a key enzyme in indole-3-acetic acid (IAA) production in A.

E. Somers; D. Ptacek; P. Gysegom; M. Srinivasan; J. Vanderleyden

2005-01-01

378

Effects of indole-3-acetic acid on croton oil- and arachidonic acid-induced mouse ear edema  

Microsoft Academic Search

The indole-3-acetic acid (IAA) is a plant growth hormone (auxin) being considered as a tryptophan metabolite in animals. The main purpose of this work was to verify IAA's topical anti-inflammatory action using croton oil- or arachidonic acid-induced mouse ear edema, in comparison to known anti-inflammatory agents. IAA antioxidant activity was also verified by measuring the inhibition of brain homogenate lipid

L. H. Jones; D. S. P. Abdalla; J. C. Freitas

1995-01-01

379

Synthesis and antiradical/antioxidant activities of caffeic acid phenethyl ester and its related propionic, acetic, and benzoic acid analogues.  

PubMed

Caffeic acid phenethyl ester (CAPE) is a bioactive component isolated from propolis. A series of CAPE analogues was synthesized and their antiradical/antioxidant effects analyzed. The effect of the presence of the double bond and of the conjugated system on the antioxidant effect is evaluated with the analogues obtained from 3-(3,4-dihydroxyphenyl) propanoic acid. Those obtained from 2-(3,4-dihydroxyphenyl) acetic acid and 3,4-dihydroxybenzoic acid allow the evaluation of the effect of the presence of two carbons between the carbonyl and aromatic system. PMID:23222926

LeBlanc, Luc M; Paré, Aurélie F; Jean-François, Jacques; Hébert, Martin J G; Surette, Marc E; Touaibia, Mohamed

2012-12-10

380

Synthesis of the Cancer Preventive Peptide Lunasin by Lactic Acid Bacteria During Sourdough Fermentation  

Microsoft Academic Search

This study aimed to exploit the potential of sourdough lactic acid bacteria to release lunasin during fermentation of cereal and nonconventional flours. The peptidase activities of a large number of sourdough lactic acid bacteria were screened using synthetic substrates. Selected lactic acid bacteria were used as sourdough starters to ferment wholemeal wheat, soybean, barley, amaranth, and rye flours. Proteinase activity

Carlo G. Rizzello; Luana Nionelli; Rossana Coda; Marco Gobbetti

2011-01-01

381

Synthesis of the Cancer Preventive Peptide Lunasin by Lactic Acid Bacteria During Sourdough Fermentation  

Microsoft Academic Search

This study aimed to exploit the potential of sourdough lactic acid bacteria to release lunasin during fermentation of cereal and nonconventional flours. The peptidase activities of a large number of sourdough lactic acid bacteria were screened using synthetic substrates. Selected lactic acid bacteria were used as sourdough starters to ferment wholemeal wheat, soybean, barley, amaranth, and rye flours. Proteinase activity

Carlo G. Rizzello; Luana Nionelli; Rossana Coda; Marco Gobbetti

2012-01-01

382

Method for the preparation of stabile microencapsulated lactic acid bacteria  

Microsoft Academic Search

Summary A method to produce viable and stabile dry microorganisms for food and agricultural purposes was developed. Spray-dried, freeze-dried or liquid culture concentrates of lactic acid-producing bacteria were mixed with various bulking agents to form a homogeneous wet granulation having a water content of 35–60% (w\\/w). The wet granulation was extruded through a dye onto a spinning plate (350–500 rpm)

H. S. Kim; B. J. Kamara; I. C. Good; G. L. Enders

1988-01-01

383

Lactic acid bacteria as adjuvants for sublingual allergy vaccines  

Microsoft Academic Search

We compared immunomodulatory properties of 11 strains of lactic acid bacteria as well as their capacity to enhance sublingual immunotherapy efficacy in a murine asthma model. Two types of bacterial strains were identified, including: (i) potent inducers of IL-12p70 and IL-10 in dendritic cells, supporting IFN-? and IL-10 production in CD4+ T cells such as Lactobacillus helveticus; (ii) pure Th1

Laurence Van Overtvelt; Helene Moussu; Stéphane Horiot; Sandrine Samson; Vincent Lombardi; Laurent Mascarell; Ariane van de Moer; Raphaëlle Bourdet-Sicard; Philippe Moingeon

2010-01-01

384

Iron Dissolution of Dust Source Materials during Simulated Acidic Processing: The Effect of Sulfuric, Acetic, and Oxalic Acids.  

PubMed

Atmospheric organic acids potentially display different capacities in iron (Fe) mobilization from atmospheric dust compared with inorganic acids, but few measurements have been made on this comparison. We report here a laboratory investigation of Fe mobilization of coal fly ash, a representative Fe-containing anthropogenic aerosol, and Arizona test dust, a reference source material for mineral dust, in pH 2 sulfuric acid, acetic acid, and oxalic acid, respectively. The effects of pH and solar radiation on Fe dissolution have also been explored. The relative capacities of these three acids in Fe dissolution are in the order of oxalic acid > sulfuric acid > acetic acid. Oxalate forms mononuclear bidentate ligand with surface Fe and promotes Fe dissolution to the greatest extent. Photolysis of Fe-oxalate complexes further enhances Fe dissolution with the concomitant degradation of oxalate. These results suggest that ligand-promoted dissolution of Fe may play a more significant role in mobilizing Fe from atmospheric dust compared with proton-assisted processing. The role of atmospheric organic acids should be taken into account in global-biogeochemical modeling to better access dissolved atmospheric Fe deposition flux at the ocean surface. PMID:23883276

Chen, Haihan; Grassian, Vicki H

2013-08-29

385

Host-guest stabilized room temperature phosphorescence in beta-cyclodextrin/ bromoalcohol solutions from 2-naphthyl-oxy-acetic acid and 1-naphthyl-acetic acid.  

PubMed

Room temperature phosphorescence (RTP) from 2-naphthyl-oxy-acetic acid (NOA) and 1-naphthyl-acetic acid (NAA), with stabilization by use of beta-cyclodextrin (beta-CD) as a host system, has been examined. 2-Bromoethanol and 2,3-dibromopropanol have been evaluated as external heavy atom perturbers to enhance the rate of intersystem crossing and, consequently, populating the triplet state for phosphorescence emission. The deoxygenation of the solutions was achieved chemically by use of sodium sulphite. The spectral characteristics of the phosphorescence emission from these relatively polar compounds and the optimization of the chemical variables involved are reported. The role of the bulkiness of the bromoalcohol employed, in comparison with the unoccupied space of the interior of the cyclodextrin cavity by the guest, is an important factor in the attainment of an effective RTP emission, and should be taken into account in the selection of the appropriate external heavy atom for the observation of RTP from other organic molecules of interest by this approach. 2,3-Dibromopropanol seems a more adequate bromoalcohol than 2-bromoethanol for the observation of RTP emission in the systems investigated. PMID:18965836

de la Pena, A M; Salinas, F; Gomez, M J; Sanchez-Pena, M; Duran-Meras, I

1993-11-01

386

Phenolic Biotransformations during Conversion of Ferulic Acid to Vanillin by Lactic Acid Bacteria  

PubMed Central

Vanillin is widely used as food additive and as a masking agent in various pharmaceutical formulations. Ferulic acid is an important precursor of vanillin that is available in abundance in cell walls of cereals like wheat, corn, and rice. Phenolic biotransformations can occur during growth of lactic acid bacteria (LAB), and their production can be made feasible using specialized LAB strains that have been reported to produce ferulic acid esterases. The present study aimed at screening a panel of LAB isolates for their ability to release phenolics from agrowaste materials like rice bran and their biotransformation to industrially important compounds such as ferulic acid, 4-ethyl phenol, vanillic acid, vanillin, and vanillyl alcohol. Bacterial isolates were evaluated using ferulic acid esterase, ferulic acid decarboxylase, and vanillin dehydrogenase assays. This work highlights the importance of lactic acid bacteria in phenolic biotransformations for the development of food grade flavours and additives.

Kaur, Baljinder; Kumar, Balvir

2013-01-01

387

Phenolic Biotransformations during Conversion of Ferulic Acid to Vanillin by Lactic Acid Bacteria.  

PubMed

Vanillin is widely used as food additive and as a masking agent in various pharmaceutical formulations. Ferulic acid is an important precursor of vanillin that is available in abundance in cell walls of cereals like wheat, corn, and rice. Phenolic biotransformations can occur during growth of lactic acid bacteria (LAB), and their production can be made feasible using specialized LAB strains that have been reported to produce ferulic acid esterases. The present study aimed at screening a panel of LAB isolates for their ability to release phenolics from agrowaste materials like rice bran and their biotransformation to industrially important compounds such as ferulic acid, 4-ethyl phenol, vanillic acid, vanillin, and vanillyl alcohol. Bacterial isolates were evaluated using ferulic acid esterase, ferulic acid decarboxylase, and vanillin dehydrogenase assays. This work highlights the importance of lactic acid bacteria in phenolic biotransformations for the development of food grade flavours and additives. PMID:24066293

Kaur, Baljinder; Chakraborty, Debkumar; Kumar, Balvir

2013-08-28

388

Growth, induction, and substrate specificity of dehydroabietic acid-degrading bacteria isolated from a kraft mill effluent enrichment.  

PubMed Central

We investigated resin acid degradation in five bacteria isolated from a bleach kraft mill effluent enrichment. All of the bacteria grew on dehydroabietic acid (DHA), a resin acid routinely detected in pulping effluents, or glycerol as the sole carbon source. None of the strains grew on acetate or methanol. Glycerol-grown, high-density, resting-cell suspensions were found to undergo a lag for 2 to 4 h before DHA degradation commenced, suggesting that this activity was inducible. This was further investigated by spiking similar cultures with tetracycline, a protein synthesis inhibitor, at various times during the DHA disappearance curve. Cultures to which the antibiotic was added prior to the lag did not degrade DHA. Those that were spiked with the antibiotic after the lag phase (4 h) degraded DHA at the same rate as did controls with no added tetracycline. Therefore, de novo protein synthesis was required for DHA biodegradation, confirming that this activity is inducible. The five strains were also evaluated for their ability to degrade other resin acids. All strains behaved in a similar fashion. Unchlorinated abietane-type resin acids (abietic acid, DHA, and 7-oxo-DHA) were completely degraded within 7 days, whereas pimarane resin acids (sandaracopimaric acid, isopimaric acid, and pimaric acid) were poorly degraded (25% or less). Chlorination of DHA affected biodegradation, with both 12,14-dichloro-DHA and 14-chloro-DHA showing resistance to degradation. However, 50 to 60% of the 12-chloro-DHA was consumed within the same period.

Bicho, P A; Martin, V; Saddler, J N

1995-01-01

389

The potential of ¹¹C-acetate PET for monitoring the Fatty acid synthesis pathway in Tumors.  

PubMed

Positron emission tomography (PET) is a molecular imaging modality that provides the opportunity to rapidly and non-invasively visualize tumors derived from multiple organs. In order to do so, PET utilizes radiotracers, such as ¹?F-FDG and ¹¹C-acetate, whose uptake coincides with altered metabolic pathways within tumors. Increased expression and activity of enzymes in the fatty acid synthesis pathway is a frequent hallmark of cancer cells. As a result, this pathway has become a prime target for therapeutic intervention. Although multiple drugs have been developed that both directly and indirectly interfere with fatty acid synthesis, an optimal means to assess their efficacy is lacking. Given that ¹¹Cacetate is directly linked to the fatty acid synthesis pathway, this probe provides a unique opportunity to monitor lipogenic tumors by PET. Herein, we review the relevance of the fatty acid synthesis pathway in cancer. Furthermore, we address the potential utility of ¹¹C-acetate PET in imaging tumors, especially those that are not FDG-avid. Last, we discuss several therapeutic interventions that could benefit from ¹¹C-acetate PET to monitor therapeutic response in patients with certain types of cancers. PMID:23597406

Deford-Watts, Laura M; Mintz, Akiva; Kridel, Steven J

2013-03-01

390

Novel wine yeast with mutations in YAP1 that produce less acetic acid during fermentation.  

PubMed

Acetic acid, a byproduct formed during yeast alcoholic fermentation, is the main component of volatile acidity (VA). When present in high concentrations in wine, acetic acid imparts an undesirable 'vinegary' character that results in a significant reduction in quality and sales. Previously, it has been shown that saké yeast strains resistant to the antifungal cerulenin produce significantly lower levels of VA. In this study, we used a classical mutagenesis method to isolate a series of cerulenin-resistant strains, derived from a commercial diploid wine yeast. Four of the selected strains showed a consistent low-VA production phenotype after small-scale fermentation of different white and red grape musts. Specific mutations in YAP1, a gene encoding a transcription factor required for oxidative stress tolerance, were found in three of the four low-VA strains. When integrated into the genome of a haploid wine strain, the mutated YAP1 alleles partially reproduced the low-VA production phenotype of the diploid cerulenin-resistant strains, suggesting that YAP1 might play a role in (regulating) acetic acid production during fermentation. This study offers prospects for the development of low-VA wine yeast starter strains that could assist winemakers in their effort to consistently produce wine to definable quality specifications. PMID:23146134

Cordente, Antonio G; Cordero-Bueso, Gustavo; Pretorius, Isak S; Curtin, Christopher D

2012-11-12

391

Metabolomic study of interactive effects of phenol, furfural, and acetic acid on Saccharomyces cerevisiae.  

PubMed

Metabolic profiling was carried out to investigate the interactive effects of three representative inhibitors (furfural, phenol, and acetic acid) in lignocellulosic hydrolysate on Saccharomyces cerevisiae during ethanol fermentation. Our results revealed that three inhibitors exhibited significantly synergistic effects on the growth, fermentation, and some metabolites of yeast. Acetic acid exerted the most severe effects on yeast in the combination of three inhibitors, enhancing amino acids metabolism and inhibiting central carbon metabolism. The effects on yeast cells by acetic acid were enhanced by the presence of phenol and furfural, which might be owing to the loss of membrane integrity and the inhibition on metabolism. Further investigation indicated that the combination of inhibitors also exhibited antagonistic effects mainly on threonine, cadaverine, inositol, and tryptophan, weakening or reversing the effects of individual inhibitor. It might be due to the more severe damage by the combined inhibitors, and different repairing mechanism of cells in the presence of individual and combined inhibitors. Better understanding of the synergistic and antagonistic effects of the inhibitors will be helpful for the improvement of tolerant strains and the optimization of lignocellulosic fermentation. PMID:21978393

Ding, Ming-Zhu; Wang, Xin; Yang, Yang; Yuan, Ying-Jin

2011-10-01

392

Kolbe electrolysis of acetic acid in a polymer electrolyte membrane reactor  

SciTech Connect

A polymer electrolyte membrane (PEM) reactor is described for use in Kolbe electrolysis: the anodic oxidation of an alkyl carboxylic acid with subsequent decarboxylation and coupling to yield a dimer, 2RCOOH {r_arrow} R-R + 2CO{sub 2} + 2e{sup {minus}} + 2H{sup +}. Platinized Nafion 117 is the PEM and functions simultaneously as the electrolyte and separator. Results demonstrating the feasibility of Kolbe electrolysis in a PEM reactor are presented for the oxidation of gaseous acetic acid (in a nitrogen diluent) to ethane and carbon dioxide, with hydrogen evolution at the counter electrode. The investigation includes the following effects on current density, current efficiency, and product selectivity: acetic acid partial pressure (P{sub total} {approx} 1 atm), cell voltage and temperature, phase of the catholyte (liquid water or humidified nitrogen), and the procedure used to prepare the membrane-electrode assembly. Current densities from 0.06 to 0.4 A/cm{sup 2} with Kolbe current efficiencies of 10 to 90% were obtained for cell voltages ranging from 4 to 10 V. The best results were obtained using PEMs platinized by a nonequilibrium impregnation-reduction method; a 75% current efficiency at 0.3 A/cm{sup 1} with a cell voltage of 6 V were measured at the following reaction conditions: 42 C reactor, 58 mm Hg acetic acid (50 C acetic acid dew point), and 42 C liquid water to the cathode. These initial results are encouraging for Kolbe electrolysis in a PEM cell; additional work, however, is needed to determine if the PEM strategy may be employed using a liquid-phase reactant. In addition, optimal reaction conditions and downstream mass-transfer separation requirements remain to be determined, both of which are reactant specific.

Hicks, M.T.; Fedkiw, P.S. [North Carolina State Univ., Raleigh, NC (United States). Dept. of Chemical Engineering

1998-11-01

393

Decadal variations of rainwater formic and acetic acid concentrations in Wilmington, NC, USA  

NASA Astrophysics Data System (ADS)

Concentrations of formic and acetic acid from January 2008 through March 2009 were compared to two previous studies at this location (conducted in 1987-1990 and 1996-1998) in order to quantify the extent to which temporal changes in DOC and pH can be explained by changes in these organic acids. The volume weighted 2008 formic and acetic acid concentrations (5.6 and 2.6 ?M respectively) have decreased dramatically compared with those observed during the 1996-1998 study (9.9 and 7.3 ?M) and are also lower than concentrations observed in the 1987-1990 study (7.4 and 3.6 ?M). Changes in formic and acetic acids between 1996-97 and 2008 can account for approximately 50% of the DOC change and 40% of the H + change in rainwater over this same time period. These changes are most pronounced during the growing season, which is also the tourist and high traffic season at this location. Determining causation of these changes is difficult due to multiple biogenic and anthropogenic sources. However, the ratio of formic to acetic acid has also reverted back to a value consistent with reduced vehicular emissions, possibly related to the introduction of improved emission control technology including the use of reformulated gasoline in the late 1990's. Long term monitoring of seasonal, annual, and decadal trends will be of critical importance for evaluating the effects of future changes to atmospheric inputs such as the increased use of ethanol and other alternative fuels.

Willey, Joan D.; Glinski, Donna A.; Southwell, Melissa; Long, Michael S.; Avery, G. Brooks, Jr.; Kieber, Robert J.

2011-02-01

394

Uncoupling by acetic acid limits growth of and acetogenesis by Clostridium thermoaceticum  

SciTech Connect

The internal pH of growing cells was measured and compared with that of nongrowing cells incubated in the absence of acetic acid. Growing cells maintained an interior about 0.6 pH units more alkaline than the exterior throughout most of batch growth (i.e., ..delta..pH = 0.6). The transmembrane electrical potential (..delta.. PSI) was also measured and was found to decrease from 140 mV at pH 7 at the beginning of growth to 80 mV when the medium had reached pH 5. The proton motive force, therefore, was 155 mV at pH 7, decreasing to 120 mV at pH 5. When further fermentation acidifed the medium below pH 5, both the ..delta..pH and the ..delta.. PSI collapsed, indicating that these cells require an internal pH of at least 5.5 to 5.7. Cells harvested from stationary phase and suspended in citrate-phosphate buffer maintained a ..delta..pH of 1.5 at external pH 5.0. This ..delta..pH was dissipated by acetic acid (at the concentrations found in the growth medium) and other weak organic acids, as well as by ionophores and inhibitors of glycolysis and of the H/sup +/-ATOase. Nongrowing cells had a ..delta.. PSI which ranged from about 116 mV at external pH 7 to about 55 mV at external pH 5 and which also was sensitive to ionophores. Since acetic acid, in its un-ionized form, diffuses passively across the cytoplasmic membrane, it effectively renders the membrane permeable to protons. It therefore seems unlikely that mutations at one or a few loci would result in C. thermoaceticum cells significantly more acetic acid tolerant than their parental type.

Baronofsky, J.J.; Schreurs, W.J.A.; Kashket, E.R.

1984-12-01

395

Rhizosphere indole-3-acetic acid as a mediator in the Sorghum bicolor-phenanthrene-Sinorhizobium meliloti interactions.  

PubMed

We studied a model system consisting of Sorghum bicolor, phenanthrene, and an auxin-producing polycyclic aromatic hydrocarbon-degrading Sinorhizobium meliloti strain to clarify whether rhizosphere indole-3-acetic acid (IAA) takes part in the plant-pollutant-bacteria interactions. Phenanthrene and S. meliloti treatments of sorghum contributed to a decrease in the rhizosphere IAA concentration and to phytohormone accumulation, respectively. Regression analysis showed significant correlations between alteration in root-zone IAA content and alterations in the root-surface area, exudation, and rhizosphere effects for culturable heterotrophic bacteria, the S. meliloti strain, and other phenanthrene degraders. According to the data obtained, phenanthrene degraders get an advantage over nondegradative rhizobacteria from IAA for rhizosphere colonization. An IAA-dependent increase in the root-surface area leads to improved sorghum growth under pollutant stress. The carbon flux from the roots is corrected by the auxin because of its influence on the exuding-surface area and on the intensity of secretion by the root cells. On the other hand, the rhizosphere IAA pool may be plant-regulated by means of alteration in carboxylate exudation and its influence on bacterial auxin production. A scenario for the IAA-mediated S. bicolor-phenanthrene-S. meliloti interactions is proposed. PMID:21459011

Golubev, Sergey N; Muratova, Anna Yu; Wittenmayer, Lutz; Bondarenkova, Anastasia D; Hirche, Frank; Matora, Larisa Yu; Merbach, Wolfgang; Turkovskaya, Olga V

2011-03-17

396

Decarboxylation of Substituted Cinnamic Acids by Lactic Acid Bacteria Isolated during Malt Whisky Fermentation  

Microsoft Academic Search

Seven strains of Lactobacillus isolated from malt whisky fermentations and representing Lactobacillus brevis, L. crispatus, L. fermentum, L. hilgardii, L. paracasei, L. pentosus, and L. plantarum contained genes for hydroxy- cinnamic acid (p-coumaric acid) decarboxylase. With the exception of L. hilgardii, these bacteria decarboxy- lated p-coumaric acid and\\/or ferulic acid, with the production of 4-vinylphenol and\\/or 4-vinylguaiacol, respec- tively, although

SYLVIE VAN BEEK; FERGUS G. PRIEST

2000-01-01

397

Dynamics of three organic acids (malic, acetic and succinic acid) in sunflower exposed to cadmium and lead.  

PubMed

Sunflower (Helianthus annuus L.) has been considered as a good candidate for bioaccumulation of heavy metals. In the present study, sunflower was used to enrich the cadmium and lead in sand culture during 90 days. Biomass, Cd and Pb uptake, three organic acids and pH in cultures were investigated. Results showed that the existence of Cd and Pb showed different interactions on the organic acids exudation. In single Cd treatments, malic and acetic acids in Cd10 showed an incremental tendency with time. In the mixed treatments of Cd and Pb, malic acids increased when 10 and 40 mg x L(-1) Cd were added into Pb50, but acetic acids in Pb50 were inhibited by Cd addition. The Cd10 supplied in Pb10 stimulated the secretion of malic and succinic acids. Moreover, the Cd or Pb uptake in sunflower showed various correlations with pH and some organic acids, which might be due to the fact that the Cd and Pb interfere with the organic acids secretion in rhizosphere of sunflower, and the changes of organic acids altered the form and bioavailability of Cd and Pb in cultures conversely. PMID:23819268

Niu, Zhixin; Li, Xiaodong; Sun, Lina; Sun, Tieheng

2013-01-01

398

The role of glass composition in the behaviour of glass acetic acid and glass lactic acid cements.  

PubMed

Cements have recently been described, made from glass ionomer glass reacted with acetic and lactic acid instead of polymeric carboxylic acid. From their behaviour a theory relating to a possible secondary setting mechanism of glass ionomer has been adduced. However, only one glass (G338) was used throughout. In this study a much simpler glass ionomer glass (MP4) was compared with G338. This produced very different results. With acetic acid G338 formed cement which became resistant to water over a period of hours, as previously reported, MP4 formed cement which was never stable to water. With lactic acid G338 behaved similarly to G338 with acetic acid, again as reported, but MP4 produced a cement which was completely resistant to water at early exposure and unusually became slightly less resistant if exposure was delayed for 6 h or more. These findings indicate that the theories relating to secondary setting in glass ionomer maturation may need revision. PMID:17619992

Shahid, Saroash; Billington, R W; Pearson, G J

2007-07-10

399

Identification of acetate-oxidizing bacteria in a coastal marine surface sediment by RNA-stable isotope probing in anoxic slurries and intact cores.  

PubMed

We investigated the terminal electron-accepting pathways and the acetate-oxidizing bacteria in surface sediment (0-5 mm depth) of Aarhus Bay, Denmark, in anoxic slurry and intact core incubations. In the intact cores, oxygen, nitrate, oxides of manganese and iron, and sulfate were all available and likely all used as electron acceptors by the microbial community, whereas microbial iron and sulfate reduction dominated in the slurries. The availability of electron acceptors clearly affected which organisms were labeled by 16S rRNA-stable isotope probing (SIP). Members of the Oceanospirillaceae were identified as (13) C-acetate oxidizers in both types of incubations, but bacteria related to Colwellia and Arcobacter oxidized acetate in the intact core, while members of the Desulfuromonadales and Acidithiobacillaceae did so in the slurry incubation. Desulfuromonadales sequences also dominated 16S rRNA gene clone libraries from the highest positive dilution of the acetate-oxidizing most probable number cultures with manganese and iron oxides. Thus, members of Desulfuromonadales are likely important for acetate oxidation coupled to iron and manganese reduction in situ, while the identified Gammaproteobacteria and affiliates of Arcobacter may utilize oxygen, nitrate and manganese oxides. Our study further highlights some of the biases that are associated with the use of RNA-SIP as well as slurry and intact core incubations. PMID:23289443

Vandieken, Verona; Thamdrup, Bo

2013-01-24

400

Response surface methodological approach for Rhizomucor miehei lipase-mediated esterification of ?-terpineol with propionic acid and acetic anhydride  

Microsoft Academic Search

Esterification of ?-terpineol with acetic anhydride or propionic acid mediated by Rhizomucor miehei lipase was subjected to a response surface study in order to optimize conditions for maximum esterification. The variables\\u000a were enzyme\\/substrate (acid) ratio, ?-terpineol concentration and incubation period using lipase from R. miehei. Between acetic anhydride and propionic acid, the former showed better yields at lower enzyme\\/substrate ratios

Pramila Rao; Soundar Divakar

2002-01-01

401

Dynamics of indole-3-acetic acid during germination of Picea abies seeds.  

PubMed

High performance liquid chromatography and combined gas chromatography-mass spectrometry were used to identify indole-3-acetic acid (IAA) and indole-3-ethanol as endogenous constituents of germinating Norway spruce (Picea abies (L.) Karst.) seeds. Indole-3-methanol was tentatively identified by multiple ion monitoring. The free IAA content of the seeds rose from about 20 ng g(-1) to about 60 ng g(-1) (dry weight) during the first five days of germination and thereafter declined to around 20 ng g(-1). Indole-3-acetic acid released by alkaline hydrolysis, which was initially present at about 110 ng g(-1), decreased to 5-10 ng g(-1) during the first week of germination. The IAA content of seed lots differing in germination behavior was investigated. The findings are discussed in relation to the metabolism of IAA in conifer seeds. PMID:14975830

Sandberg, G; Ernstsen, A

1987-06-01

402

DFT computation and experimental analysis of vibrational and electronic spectra of phenoxy acetic acid herbicides.  

PubMed

An absolute vibrational analysis has been attempted on the basis of experimental FTIR and NIR-FT Raman spectra with calculated vibrational wavenumbers and intensities of phenoxy acetic acids. The equilibrium geometry, bonding features and harmonic vibrational wavenumbers have been calculated with the help of B3LYP method with Dunning correlation consistent basis set aug-cc-pVTZ. The electronic structures of molecular fragments were described in terms of natural bond orbital analysis, which shows intermolecular O-H···O and intramolecular C-H···O hydrogen bonds. The electronic absorption spectra with different solvents have been investigated in combination with time-dependent density functional theory calculation. The pKa values of phenoxy acetic acids were compared. PMID:23466319

Arul Dhas, D; Hubert Joe, I; Roy, S D D; Balachandran, S

2013-02-09

403

DFT computation and experimental analysis of vibrational and electronic spectra of phenoxy acetic acid herbicides  

NASA Astrophysics Data System (ADS)

An absolute vibrational analysis has been attempted on the basis of experimental FTIR and NIR-FT Raman spectra with calculated vibrational wavenumbers and intensities of phenoxy acetic acids. The equilibrium geometry, bonding features and harmonic vibrational wavenumbers have been calculated with the help of B3LYP method with Dunning correlation consistent basis set aug-cc-pVTZ. The electronic structures of molecular fragments were described in terms of natural bond orbital analysis, which shows intermolecular Osbnd H⋯O and intramolecular Csbnd H⋯O hydrogen bonds. The electronic absorption spectra with different solvents have been investigated in combination with time-dependent density functional theory calculation. The pKa values of phenoxy acetic acids were compared.

Arul Dhas, D.; Hubert Joe, I.; Roy, S. D. D.; Balachandran, S.

2013-05-01

404

Biofilm formation by lactic acid bacteria and resistance to environmental stress.  

PubMed

We investigated the formation of biofilms by 3 type strains of lactic acid bacteria (LAB), Lactobacillus plantarum, Lactobacillus brevis and Lactobacillus fructivorans, as representatives of LAB that cause food deterioration or contamination. Lactobacillus plantarum subsp. plantarum JCM1149 and Lactobacillus brevis JCM1059 appeared to adhere and accumulate on glass cover slips. Lactobacillus fructivorans JCM1117 cells made thin cellophane-like biofilms, and most of the biofilm cells became longer than the planktonic cells. We tested the resistance of biofilm and planktonic L. plantarum subsp. plantarum JCM1149 cells to acetic acid and ethanol, which strongly inhibit the growth of bacteria and are important in food preservation. The biofilm cells were more resistant than the planktonic cells and the surfaces of the treated planktonic cells were badly damaged, whereas those of the biofilm cells were only slightly damaged. We isolated 43 LAB from onions and the biofolm cells of an isolate, L. plantarum M606 also had high resistance. These results demonstrate the significance of studying biofilms of LAB in the food industry. PMID:19000615

Kubota, Hiromi; Senda, Shouko; Nomura, Nobuhiko; Tokuda, Hajime; Uchiyama, Hiroo

2008-10-01

405

Amino acids as main substrates for sulfate-reducing bacteria in surface sediment of a eutrophic bay.  

PubMed

The inner part of Tokyo Bay, Japan, is highly eutrophicated as shown by the frequent occurrence of red tide. The bottom water is anoxic during warm seasons especially at artificially dredged sites. In the sediment slurries prepared from surface sediment samples collected from the dredged sites, substrate addition stimulated the consumption of sulfate during anaerobic incubation. Of the substrates added, the seston composed mainly of diatom stimulated consumption more than lactate and acetate. Its effect was nearly equal to that of casamino acids. Casamino acids and some amino acids also accelerated the rate of sulfate reduction measured by the tracer method in sediment samples more than lactate or acetate. Anaerobic incubation of the sediment slurry amended with casamino acids showed that the consumption of amino acids was retarded by the addition of molybdate (final concentration; 20 mM). In the slurry amended with only molybdate, glutamate was accumulated distinctively and linearly with time. Its accumulation rate in molar base was comparable to the rate of sulfate reduction. These results suggested that amino acids were the main substrates for sulfate-reducing bacteria (SRB) in the sediment. The MPN values of SRB in these sediment samples were often higher with the enumeration medium containing casamino acids instead of lactate. Furthermore, during a week incubation of sediment slurries amended with substrates, casamino acids and seston more greatly stimulated the growth of SRB enumerated by both media than lactate. PMID:14747974

Takii, Susumu

2003-12-01

406

Study of acetic acid production by immobilized acetobacter cells: oxygen transfer  

Microsoft Academic Search

The immobilization of living Acetobacter cells by adsorption onto a large-surface-area ceramic support was studied in a pulsed flow reactor. The high oxygen transfer capability of the reactor enabled acetic acid production rates up to 10.4 g\\/L\\/h to be achieved. Using a simple mathematical model incorporating both internal and external mass transfer coefficients, it was shown that oxygen transfer in

C. Ghommidh; J. M. Navarro; G. Durand

1982-01-01

407

Relation of Dietary Acetate and Lactates to Dry Matter Intake and Volatile Fatty Acid Metabolism1  

Microsoft Academic Search

Effects of feeding lactates and acetate supplemental to a basal ration of two-thirds sorghum silage and one-third mixture of beet pulp and soybean oil meal were deter- mined, using five heifers in a 5 × 5 Latin- square design. Rations were fed ad libitum. Lactates were added to give 9.0% lactic acid equivalent in the ration dry matter (HL) and

S. H. Senel; F. G. Owen

1966-01-01

408

Central hypotensive effects of imidazole acetic acid and rolipram (ZK 62 711) in rats  

Microsoft Academic Search

In urethane-anaesthetized rats the administration of imidazole acetic acid (IAA), 34–272 ?g per rat intracerebroventricularly (i.c.v.), induced a dose-related fall in blood pressure. Rolipram (ZK 62 711), a potent and selective inhibitor of cyclic AMP phosphodiesterase (cAMP-PDE), also lowered the blood pressure in a dose-dependent manner when administered at the doses of 1–64 ?g per rat i.c.v. A subhypotensive dose

H. Karppanen; Pirkko Paakkari; Anna-Liisa Orma; I. Paakkari

1979-01-01

409

Temperature-Sensitive Plant Cells with Shunted Indole3Acetic Acid Conjugation  

Microsoft Academic Search

Cells of henbane (Hyoscyamus muticus L.) grow indefinitely in culture without exogenous auxin. Cells of its temperature-sensitive variant XIlB2 grow like the wild type at 26OC but die rapidly at 33°C unless auxin is added to the medium. Despite this temperature- sensitive auxin auxotrophy, XllB2 produces wild-type amounts of indole-3-acetic acid (IAA). IAA is the predominant auxin and is important

Jiirg H. Oetiker; Ceorg Aeschbacher

1997-01-01

410

Sequential induction of the ethylene biosynthetic enzymes by indole-3-acetic acid in etiolated peas  

Microsoft Academic Search

Ethylene induced an increase in the accumulation of 1-aminocyclopropane-1-carboxylate (ACC) oxidase transcript level and enzyme activity in the first internode of 5- to 6-day-old etiolated pea (Pisum sativum L.) seedlings. Indole-3-acetic acid (IAA), which stimulates ethylene production by enhancing ACC synthase activity, also caused an increase in ACC oxidase transcript and activity levels. The IAA-induced increase in ACC oxidase mRNA

Scott C. Peck; Hans Kende

1995-01-01

411

Tachyphylaxis in 12-0-Tetradecanoylphorbol Acetate and Arachidonic Acid-Induced Ear Edema  

Microsoft Academic Search

12-0-Tetradecanoylphorbol acetate (TPA) applied to mouse ears rapidly induces an edema which is maximal by 6 hr but has substantially waned by 24 hr. (This is in contrast to many inflammatory agents that cause a prolonged edema lasting many days.) Reapplication of TPA at 16-24 hr will not provoke a second edematous response although increased erythema is evident. Arachidonic acid

John M. Young; Bonnie M. Wagner; Doreen A. Spires

1983-01-01

412

Direct catalytic conversion of methane to acetic acid in an aqueous medium  

Microsoft Academic Search

ALTHOUGH methane is the most-abundant of alkanes, hazards of handling and distribution prevent known methane reserves1,2 from being fully exploited. Moreover, it is the least reactive alkane, so whereas selective conversion to more useful chemical products would be of great value, it is difficult to achieve. A useful target molecule for methane conversion is acetic acid, but existing approaches to

Minren Lin; Ayusman Sen

1994-01-01

413

(Aminooxy)acetic acid inhibits petunia growth and gibberellin- and cytokinin-stimulated growth in bioassays  

Microsoft Academic Search

(Aminooxy)acetic acid (AOA) was applied to greenhouse-grown petunias and was used in bioassays for three plant growth hormones\\u000a so that its growth regulator properties could be studied. In greenhouse studies foliar sprays of 4.8–12 mm AOA inhibited vegetative growth of petunia seedlings (Petunia xhybrida Vilm. ‘White Flash’). When gibberellin A 3 (GA3) was applied to shoot tips previously treated with

Philip E. Hammer; David S. Koranski; Richard J. Gladont

1995-01-01

414

MoVO-based catalysts for the oxidation of ethane to ethylene and acetic acid  

Microsoft Academic Search

The influence of niobium and\\/or palladium in MoV0.4Ox on both solid state chemistry and catalytic properties in the oxidation of ethane to acetic acid and ethylene is examined. Catalysts without molybdenum (VNb0.31Pd3e-4Ox) are also studied for comparison. The structural properties of the precursors and of the catalysts obtained by calcination of precursors at 350 and 400°C are studied by X-ray

Martial Roussel; Michel Bouchard; Khalid Karim; Saleh Al-Sayari; Elisabeth Bordes-Richard

2006-01-01

415

Oxidation of ethane to ethylene and acetic acid by MoVNbO catalysts  

Microsoft Academic Search

The influence of niobium on the physicochemical properties of the MoVO system and on its catalytic properties in the oxidation of ethane to ethylene and acetic acid is examined. Solids based on MoV0.4Ox and MoV0.4Nb0.12Oy composition and calcined at 350 or 400°C were studied by X-ray diffraction, and by laser Raman and X-ray photoelectron spectroscopies. Their reactivity during reduction and

M. Roussel; M. Bouchard; E. Bordes-Richard; K. Karim; S. Al-Sayari

2005-01-01

416

Brettanomyces bruxellensis : effect of oxygen on growth and acetic acid production  

Microsoft Academic Search

The influence of the oxygen supply on the growth, acetic acid and ethanol production by Brettanomyces bruxellensis in a glucose medium was investigated with different air flow rates in the range 0-300 l h-1 (0-0.5 vvm). This study shows that growth of this yeast is stimulated by moderate aeration. The optimal oxygen supply for cellular synthesis was an oxygen transfer

M. G. Aguilar Uscanga; M.-L. Délia; P. Strehaiano

2003-01-01

417

Evaluation of adsorption effects on measurements of ammonia, acetic acid, and methanol  

Microsoft Academic Search

We examined how adsorption and desorption of gases from inlets and a cell could affect the accuracy of closed-cell FTIR measurements of carbon dioxide (CO2), carbon monoxide (CO), methane (CH4), nitric oxide (NO), nitrogen dioxide (NO2), methanol (CH3OH), acetic acid (CH3COOH), and ammonia (NH3). When standards were delivered to the cell through a stainless steel inlet, temporarily reduced transmission was

R. J. Yokelson; T. J. Christian; I. T. Bertschi; W. M. Hao

2003-01-01

418

Interactions of human serum albumin with retinoic acid, retinal and retinyl acetate  

Microsoft Academic Search

Human serum albumin (HSA), a major plasma protein and plasma-derived therapeutic, interacts with a wide variety of drugs and native plasma metabolites. In this study the interactions between HSA and small lipophilic molecules all-trans retinoic acid (RA), all-trans retinaldehyde (retinal, RAL) and all-trans retinyl acetate (RAC) were investigated by UV–vis absorption spectroscopy, fluorescence spectroscopy and circular dichroism (CD). This paper

Elena Karnaukhova

2007-01-01

419

Indole3-acetic Acid Sensitization of Phytochrome-Controlled Growth of Coleoptile Sections  

Microsoft Academic Search

Addition of 6 mu M indole-3-acetic acid (IAA) to incubation buffer increases the sensitivity of coleoptile sections cut from dark-grown Avena sativa L. cv. Lodi to red light by a factor of 10,000, relative to the response in the absence of added IAA, without changing the maximum amount of light-induced growth. From 0.03 to 4 mu M IAA sections show

James R. Shinkle; Winslow R. Briggs

1984-01-01

420

Effect of oleic acid plasticizer on chitosan–lithium acetate solid polymer electrolytes  

Microsoft Academic Search

Plasticized polymer electrolytes composed of chitosan as the host polymer, oleic acid (OA) as the plasticizer and lithium acetate (LiOAc) as the doping salt were prepared by the solution cast technique. These complexes with different amounts of salts and plasticizers were investigated as possible ionic conducting polymers. The highest ionic conductivity of the plasticized chitosan–LiOAc was ?10?5 Scm?1 for the

M. Z. A. Yahya; A. K. Arof

2003-01-01

421

Growth and survival of lactic acid bacteria in lucerne silage.  

PubMed

A rifampicin-resistant variant of two strains of Lactobacillus plantarum, one strain of Pediococcus acidilactici, and one strain of Enterococcus faecium were used for the experimental production of lucerne silage. Laboratory silage without inoculants served as a control. Counts of total anaerobes, total lactic acid bacteria (LAB), lactobacilli, pediococci, and enterococci were determined on days 14, 21, 30, 49, and 60 of lucerne fermentation. LAB dominated in silage microflora, reaching a percentage between 59 and 95 % of total anaerobes. Lactobacilli were found as a predominant group of LAB during the whole study. Lactobacilli reached numbers 8.74 log CFU/g in treated silage and 8.89 log CFU/g in the control at the first observation. Their counts decreased to 4.23 and 4.92 log CFU/g in treated silage and the control, respectively, on day 63 of fermentation. Similar decreases were observed in all bacterial groups. The treated silage samples possessed lower pH (4.2 vs. 4.5 in control samples) and contained more lactic acid compared to control silage. The identity of re-isolated rifampicin-resistant bacteria with those inoculated to the lucerne was evaluated by fingerprinting techniques. The fingerprint profiles of re-isolated bacteria corresponded to the profiles of strains used for the treatment. It could be concluded that supplemented LAB dominated in laboratory silage and overgrew naturally occurring LAB. PMID:22491990

Vlková, Eva; Rada, Vojt?ch; Bunešová, V?ra; Ro?ková, Sárka

2012-04-11

422

Improving the environmental profile of wood panels via co-production of ethanol and acetic acid.  

PubMed

The oriented strand board (OSB) biorefinery is an emerging technology that could improve the building, transportation, and chemical sectors' environmental profiles. By adding a hot water extraction stage to conventional OSB panel manufacturing, hemicellulose polysaccharides can be extracted from wood strands and converted to renewably sourced ethanol and acetic acid. Replacing fossil-based gasoline and acetic acid has the potential to reduce greenhouse gas (GHG) emissions, among other possible impacts. At the same time, hemicellulose extraction could improve the environmental profile of OSB panels by reducing the level of volatile organic compounds (VOCs) emitted during manufacturing. In this study, the life cycle significance of such GHG, VOC, and other emission reductions was investigated. A process model was developed based on a mix of laboratory and industrial-level mass and energy flow data. Using these data a life cycle assessment (LCA) model was built. Sensitive process parameters were identified and used to develop a target production scenario for the OSB biorefinery. The findings suggest that the OSB biorefinery's deployment could substantially improve human and ecosystem health via reduction of select VOCs compared to conventionally produced OSB, gasoline, and acetic acid. Technological advancements are needed, however, to achieve desirable GHG reductions. PMID:21967719

Earles, J Mason; Halog, Anthony; Shaler, Stephen

2011-10-17

423

Dual Antiplatelet Regime Versus Acetyl-acetic Acid for Carotid Artery Stenting  

SciTech Connect

Carotid artery stenting has been proposed as an option treatment of carotid artery stenosis. The aim of this single-institution study is to compare the dual-antiplatelet treatment and heparin combined with acetyl-acetic acid, in patients who underwent carotid artery stenting. We compared 2 groups of 50 patents each who underwent carotid artery stenting for primary atherosclerotic disease. Group A received heparin for 24 h combined with 325 mg acetyl-acetic acid and group B received 250 mg ticlopidine twice a day combined with 325 mg acetyl-acetic acid. Outcome measurements included 30-day bleeding and neurological complications and 30-day thrombosis/occlusion rates. The neurological complications were 16% in group A and 2% in group B (p < 0.05). Bleeding complications occurred in 4% in group A and 2% in group B (p > 0.05). The 30-day thrombosis/occlusion rate was 2% in group A and 0% in group B (p > 0.05). Dual antiplatelet treatment is recommended in all patients undergoing carotid artery stenting.

Dalainas, Ilias, E-mail: hdlns@freemail.gr; Nano, Giovanni; Bianchi, Paolo; Stegher, Silvia; Malacrida, Giovanni; Tealdi, Domenico G. [University of Milan, Istituto Policlinico San Donato, 1st Unit of Vascular Surgery (Italy)

2006-08-15

424

Intermolecular proton-transfer in acetic acid clusters induced by vacuum-ultraviolet photoionization  

NASA Astrophysics Data System (ADS)

Infrared (IR) spectroscopy based on vacuum-ultraviolet one-photon ionization detection was carried out to investigate geometric structures of neutral and cationic clusters of acetic acid: (CH3COOH)2, CH3COOH-CH3OH, and CH3COOH-H2O. All the neutral clusters have cyclic-type intermolecular structures, in which acetic acid and solvent molecules act as both hydrogen donors and acceptors, and two hydrogen-bonds are formed. On the other hand, (CH3COOH)2+ and (CH3COOH-CH3OH)+ form proton-transferred structures, where the acetic acid moiety donates the proton to the counter molecule. (CH3COOH-H2O)+ has a non-proton-transferred structure, where CH3COOH+ and H2O are hydrogen-bonded. The origin of these structural differences among the cluster cations is discussed with the relative sizes of the proton affinities of the cluster components and the potential energy curves along the proton-transfer coordinate.

Ohta, Keisuke; Matsuda, Yoshiyuki; Mikami, Naohiko; Fujii, Asuka

2009-11-01

425

Acetic acid and lithium chloride effects on hydrothermal carbonization of lignocellulosic biomass.  

PubMed

As a renewable non-food resource, lignocellulosic biomass has great potential as an energy source or feedstock for further conversion. However, challenges exist with supply logistics of this geographically scattered and perishable resource. Hydrothermal carbonization treats any kind of biomass in 200 to 260°C compressed water under an inert atmosphere to produce a hydrophobic solid of reduced mass and increased fuel value. A maximum in higher heating value (HHV) was found when 0.4 g of acetic acid was added per g of biomass. If 1g of LiCl and 0.4 g of acetic acid were added per g of biomass to the initial reaction solution, a 30% increase in HHV was found compared to the pretreatment with no additives, along with greater mass reduction. LiCl addition also reduces reaction pressure. Addition of acetic acid and/or LiCl to hydrothermal carbonization each contribute to increased HHV and reduced mass yield of the solid product. PMID:21411315

Lynam, Joan G; Coronella, Charles J; Yan, Wei; Reza, Mohammad T; Vasquez, Victor R

2011-02-13

426

Repetitive sequence based polymerase chain reaction to differentiate close bacteria strains in acidic sites  

Microsoft Academic Search

To study the diversity of bacteria strains newly isolated from several acid mine drainage(AMD) sites in China, repetitive sequence based polymerase chain reaction (rep-PCR), a well established technology for diversity analysis of closely related bacteria strains, was conducted on 30 strains of bacteria Leptospirillum ferriphilium, 8 strains of bacteria Acidithiobacillus ferrooxidans, as well as the Acidithiobacillus ferrooxidans type strain ATCC

Ming XIE; Hua-qun YIN; Yi LIU; Jie LIU; Xue-duan LIU

2008-01-01

427

Sol-gel processing of yttria-stabilized zirconia films derived from the zirconium n -butoxide-acetic acid-nitric acid-water-isopropanol system  

Microsoft Academic Search

A stable yttria-stabilized zirconia (YSZ) sol has been synthesized by the controlled hydrolysis of zirconium n-butoxide. Acetic acid and nitric acid were used as chelating agent and catalyst, respectively. The addition of acetic acid and increasing the amount of nitric acids to the system significantly enhanced the sol stability. The viscosity of YSZ sol with the concentration less than 0.80

Seung-Goo Kim; Suk Woo Nam; Sung-Pil Yoon; Sang-Hoon Hyun; Jonghee Han; Tae-Hoon Lim; Seong-Ahn Hong

2004-01-01

428

Screening and characterization of novel bacteriocins from lactic acid bacteria.  

PubMed

Bacteriocins produced by lactic acid bacteria (LAB) are expected to be safe antimicrobial agents. While the best studied LAB bacteriocin, nisin A, is widely utilized as a food preservative, various novel ones are required to control undesirable bacteria more effectively. To discover novel bacteriocins at the early step of the screening process, we developed a rapid screening system that evaluates bacteriocins produced by newly isolated LAB based on their antibacterial spectra and molecular masses. By means of this system, various novel bacteriocins were identified, including a nisin variant, nisin Q, a two-peptide bacteriocin, lactococcin Q, a leaderless bacteriocin, lacticin Q, and a circular bacteriocin, lactocyclicin Q. Moreover, some LAB isolates were found to produce multiple bacteriocins. They were characterized as to their structures, mechanisms of action, and biosynthetic mechanisms. Novel LAB bacteriocins and their biosynthetic mechanisms are expected for applications such as food preservation and peptide engineering. PMID:23649268

Zendo, Takeshi

2013-05-07

429

Development of Mucosal Vaccines Based on Lactic Acid Bacteria  

NASA Astrophysics Data System (ADS)

Today, sufficient data are available to support the use of lactic acid bacteria (LAB), notably lactococci and lactobacilli, as delivery vehicles for the development of new mucosal vaccines. These non-pathogenic Gram-positive bacteria have been safely consumed by humans for centuries in fermented foods. They thus constitute an attractive alternative to the attenuated pathogens (most popular live vectors actually studied) which could recover their pathogenic potential and are thus not totally safe for use in humans. This chapter reviews the current research and advances in the use of LAB as live delivery vectors of proteins of interest for the development of new safe mucosal vaccines. The use of LAB as DNA vaccine vehicles to deliver DNA directly to antigen-presenting cells of the immune system is also discussed.

Bermúdez-Humarán, Luis G.; Innocentin, Silvia; Lefèvre, Francois; Chatel, Jean-Marc; Langella, Philippe

430

Pb(II) and Zn(II) adsorption onto Na and Ca-montmorillonites in acetic acid\\/acetate medium: Experimental approach and geochemical modeling  

Microsoft Academic Search

Smectites are usually used as a clay barrier at the bottom of subsurface waste landfills due to their low permeability and their capacity to retain pollutants. The Na- and Ca-saturated SWy2 montmorillonites were interacted with initial Zn(NO3)2 or Pb(NO3)2 concentrations ranging from 10?6 to 10?2M with a solid\\/liquid ratio of 10gL?1 and using acetic acid\\/acetate as buffer at pH 5

Mariem Ghayaza; Lydie Le Forestier; Fabrice Muller; Christophe Tournassat; Jean-Michel Beny

2011-01-01

431

Occurrence and role of lactic acid bacteria in seafood products.  

PubMed

Lactic acid bacteria (LAB) in fish flesh has long been disregarded because the high post-mortem pH, the low percentage of sugars, the high content of low molecular weight nitrogenous molecules and the low temperature of temperate waters favor the rapid growth of pH-sensitive psychrotolerant marine Gram-negative bacteria like Pseudomonas, Shewanella and Photobacterium. In seafood packed in both vacuum (VP) and modified atmosphere (MAP) packaging commonly CO(2) enriched, the growth of the Gram-negative aerobic bacteria group (predominantly pseudomonads) is effectively inhibited and the number reached by LAB during storage is higher than that achieved in air but always several log units lower than the trimethylamine oxide (TMA-O) reducing and CO(2)-resistant organisms (Shewanella putrefaciens and Photobacterium phosphoreum). Accordingly, LAB are not of much concern in seafood neither aerobically stored nor VP and MAP. However, they may acquire great relevance in lightly preserved fish products (LPFP), including those VP or MAP. Fresh fish presents a very high water activity (aw) value (0.99). However, aw is reduced to about 0.96 when salt (typically 6% WP) is added to the product. As a result, aerobic Gram-negative bacteria are inhibited, which allows the growth of other organisms more resistant to reduced aw, i.e. LAB, and then they may acquire a central role in the microbial events occurring in the product. Changes in consumers' habits have led to an increase of convenient LPFP with a relative long shelf-life (at least 3 weeks) which, on the other hand, may constitute a serious problem from a safety perspective since Listeria monocytogenes and sometimes Clostridium botulinum (mainly type E) may able to grow. In any case the LAB function in marine products is complex, depending on species, strains, interaction with other bacteria and the food matrix. They may have no particular effect or they may be responsible for spoilage and, in certain cases, they may even exert a bioprotective effect in relation to undesirable bacteria. The bioprotective potential of endogenous LAB in relation to pathogens and spoiling bacteria has often been highlighted. However, the technology is still in its infancy compared with foods dairy and meat products in which either the carbohydrate content (dairy products) or sugar and salt added (meat products) favor the acidification by LAB that enable a natural preservation of the product. Successful studies on LAB as probiotic for fish intensify, but this potential is still to be explored for human. Although not usual, some applications of LAB for fermentation of marine products and by-products are described. PMID:20630312

Françoise, Leroi

2010-05-25

432

Growth and Metabolism of Lactic Acid Bacteria during and after Malolactic Fermentation of Wines at Different pH  

PubMed Central

Commercially produced red wines were adjusted to pH 3.0, 3.2, 3.5, 3.7, or 4.0 and examined during and after malolactic fermentation for growth of lactic acid bacteria and changes in the concentrations of carbohydrates, organic acids, amino acids, and acetaldehyde. With one exception, Leuconostoc oenos conducted the malolactic fermentation in all wines and was the only species to occur in wines at pH below 3.5. Malolactic fermentation by L. oenos was accompanied by degradation of malic, citric, and fumaric acids and production of lactic and acetic acids. The concentrations of arginine, histidine, and acetaldehyde also decreased at this stage, but the behavior of hexose and pentose sugars was complicated by other factors. Pediococcus parvulus conducted the malolactic fermentation in one wine containing 72 mg of total sulfur dioxide per liter. Fumaric and citric acids were not degraded during this malolactic fermentation, but hexose sugars were metabolized. P. parvulus and species of Lactobacillus grew after malolactic fermentation in wines with pH adjusted above 3.5. This growth was accompanied by the utilization of wine sugars and production of lactic and acetic acids.

Davis, C. R.; Wibowo, D. J.; Lee, T. H.; Fleet, G. H.

1986-01-01

433

Modeling the effects of sucuk production technique on Listeria monocytogenes, aerobic bacteria and lactic acid bacteria during ripening and storage  

Microsoft Academic Search

The modeling of sucuk (Turkish dry-fermented sausage) production techniques on the survival of Listeria monocytogenes, aerobic bacteria (AB), lactic acid bacteria (LAB), and yeasts and molds (YM) during ripening and storage periods were studied. Effect of L. monocytogenes initially contaminated level (low, medium and high contaminated levels) with sucuk dough was also studied. Survival data were analyzed by non-linear regression

Osman Erkmen

2008-01-01

434

Lactic acid bacteria with health claims—interactions and interference with gastrointestinal flora  

Microsoft Academic Search

Lactic acid bacteria in foods have a long history of safe use. Members of the genera Lactococcus and Lactobacillus have a ‘generally-recognised-as-safe’ status, whilst members of the genera Streptococcus and Enterococcus and some other genera of lactic acid bacteria contain opportunistic pathogens. New species and more specific strains of probiotic bacteria are constantly being identified. Prior to incorporating new strains

Tiina Mattila-Sandholm; Jaana Mättö; Maria Saarela

1999-01-01

435

Extractable Lipids of Gram-Negative Marine Bacteria: Fatty - Acid Composition  

Microsoft Academic Search

Fatty-acid compositions were determined for 20 strains of marine and estuarine bacteria and two strains representative of terrestrial species. Results showed that the fatty acids of marine bacteria differed little from those of nonmarine organisms, and a primary role for hexadecenoic acid was indicated. Of the 20 strains examined, with the exception of one, the major fatty-acid species were C

JAMES D. OLIVER; RITA R. COLWELL

436

Acetic Acid Activates the AMP-Activated Protein Kinase Signaling Pathway to Regulate Lipid Metabolism in Bovine Hepatocytes  

PubMed Central

The effect of acetic acid on hepatic lipid metabolism in ruminants differs significantly from that in monogastric animals. Therefore, the aim of this study was to investigate the regulation mechanism of acetic acid on the hepatic lipid metabolism in dairy cows. The AMP-activated protein kinase (AMPK) signaling pathway plays a key role in regulating hepatic lipid metabolism. In vitro, bovine hepatocytes were cultured and treated with different concentrations of sodium acetate (neutralized acetic acid) and BML-275 (an AMPK? inhibitor). Acetic acid consumed a large amount of ATP, resulting in an increase in AMPK? phosphorylation. The increase in AMPK? phosphorylation increased the expression and transcriptional activity of peroxisome proliferator-activated receptor ?, which upregulated the expression of lipid oxidation genes, thereby increasing lipid oxidation in bovine hepatocytes. Furthermore, elevated AMPK? phosphorylation reduced the expression and transcriptional activity of the sterol regulatory element-binding protein 1c and the carbohydrate responsive element-binding protein, which reduced the expression of lipogenic genes, thereby decreasing lipid biosynthesis in bovine hepatocytes. In addition, activated AMPK? inhibited the activity of acetyl-CoA carboxylase. Consequently, the triglyceride content in the acetate-treated hepatocytes was significantly decreased. These results indicate that acetic acid activates the AMPK? signaling pathway to increase lipid oxidation and decrease lipid synthesis in bovine hepatocytes, thereby reducing liver fat accumulation in dairy cows.

Li, Xinwei; Chen, Hui; Guan, Yuan; Li, Xiaobing; Lei, Liancheng; Liu, Juxiong; Yin, Liheng; Liu, Guowen; Wang, Zhe

2013-01-01

437

Cell membrane damage induced by phenolic acids on wine lactic acid bacteria.  

PubMed

The aim of this work was to investigate the effect of phenolic acids on cell membrane permeability of lactic acid bacteria from wine. Several phenolic acids were tested for their effects on the cell membrane of Oenococcus oeni and Lactobacillus hilgardii by measuring potassium and phosphate efflux, proton influx and by assessing culture viability employing a fluorescence technique based on membrane integrity. The experimental results indicate that hydroxycinnamic acids (p-coumaric, caffeic and ferulic acids) induce greater ion leakages and higher proton influx than hydroxybenzoic acids (p-hydroxibenzoic, protocatechuic, gallic, vanillic, and syringic acids). Among the hydroxycinnamic acids, p-coumaric acid showed the strongest effect. Moreover, the exposure of cells to phenolic acids caused a significant decrease in cell culture viability, as measured by the fluorescence assay, in both tested strains. The results agree with previous results obtained in growth experiments with the same strains. Generally, phenolic acids increased the cell membrane permeability in lactic acid bacteria from wine. The different effects of phenolic acids on membrane permeability could be related to differences in their structure and lipophilic character. PMID:19733929

Campos, F M; Couto, J A; Figueiredo, A R; Tóth, I V; Rangel, A O S S; Hogg, T A

2009-08-04

438

Fermentation of aqueous plant seed extracts by lactic acid bacteria  

SciTech Connect

The effects of lactic acid bacterial fermentation on chemical and physical changes in aqueous extracts of cowpea (Vigna unguiculata), peanut (Arachis hypogea), soybean (Glycine max), and sorghum (Sorghum vulgare) were studied. The bacteria investigated were Lactobacillus helveticus, L. delbrueckii, L. casei, L. bulgaricus, L. acidophilus, and Streptococcus thermophilus. Organisms were inoculated individually into all of the seed extracts; L. bulgaricus and S. thermophilus were also evaluated together as inocula for fermenting the legume extracts. During fermentation, bacterial population and changes in titratable acidity, pH, viscosity, and color were measured over a 72 h period at 37 degrees C. Maximum bacterial populations, titratable acidity, pH, and viscosity varied depending upon the type of extract and bacterial strain. The maximum population of each organism was influenced by fermentable carbohydrates, which, in turn, influenced acid production and change in pH. Change in viscosity was correlated with the amount of protein and titratable acidity of products. Color was affected by pasteurization treatment and fermentation as well as the source of extract. In the extracts inoculated simultaneously with L. bulgaricus and S. thermophilus, a synergistic effect resulted in increased bacterial populations, titratable acidity, and viscosity, and decreased pH in all the legume extracts when compared to the extracts fermented with either of these organisms individually. Fermented extracts offer potential as substitutes for cultured dairy products. 24 references.

Schafner, D.W.; Beuchat, R.L.

1986-05-01

439

Fermentation of Aqueous Plant Seed Extracts by Lactic Acid Bacteria  

PubMed Central

The effects of lactic acid bacterial fermentation on chemical and physical changes in aqueous extracts of cowpea (Vigna unguiculata), peanut (Arachis hypogea), soybean (Glycine max), and sorghum (Sorghum vulgare) were studied. The bacteria investigated were Lactobacillus helveticus, L. delbrueckii, L. casei, L. bulgaricus, L. acidophilus, and Streptococcus thermophilus. Organisms were inoculated individually into all of the seed extracts; L. bulgaricus and S. thermophilus were also evaluated together as inocula for fermenting the legume extracts. During fermentation, bacterial population and changes in titratable acidity, pH, viscosity, and color were measured over a 72-h period at 37°C. Maximum bacterial populations, titratable acidity, pH, and viscosity varied depending upon the type of extract and bacterial strain. The maximum population of each organism was influenced by fermentable carbohydrates, which, in turn, influenced acid production and change in pH. Change in viscosity was correlated with the amount of protein and titratable acidity of products. Color was affected by pasteurization treatment and fermentation as well as the source of extract. In the extracts inoculated simultaneously with L. bulgaricus and S. thermophilus, a synergistic effect resulted in increased bacterial populations, titratable acidity, and viscosity, and decreased pH in all the legume extracts when compared to the extracts fermented with either of these organisms individually. Fermented extracts offer potential as substitutes for cultured dairy products.

Schaffner, Donald W.; Beuchat, Larry R.

1986-01-01

440

Energy Requirements for Fatty Acid and Glycerolipid Biosynthesis from Acetate by Isolated Pea Root Plastids 1  

PubMed Central

Fatty acid and glycerolipid biosynthesis from [14C]acetate by isolated pea root plastids is completely dependent on exogenously supplied ATP. CTP, GTP, and UTP are ineffective in supporting fatty acid biosynthesis, all resulting in <3% of the activity obtained with ATP. However, ADP alone or in combination with inorganic phosphate (Pi) or pyrophosphate (PPi) gave up to 28% of the ATP control activity, whereas AMP + PPi, PPi alone, or Pi alone were ineffective in promoting fatty acid biosynthesis. The components of the dihydroxyacetonephosphate (DHAP) shuttle (DHAP, oxaloacetate, and Pi), which promote intraplastidic ATP synthesis, restored 41% of the control ATP activity, whereas the omission of any of the shuttle components abolished this activity. When the DHAP shuttle components were supplemented with ADP, the rate of fatty acid biosynthesis was completely restored to that observed in the presence of ATP. Under the conditions of ADP + DHAP shuttle-driven fatty acid biosynthesis, exogenously supplied ATP gave only a 6% additional stimulation of activity. In general, variations in the energy source had only small effects on the proportions of radioactive fatty acids and glycerolipids synthesized. Most notably, higher amounts of radioactive oleic acid, free fatty acids, and diacylglycerol and lower amounts of phosphatidic acid were observed when ADP and/or the DHAP shuttle were substituted for ATP. The results presented here indicate that, although isolated pea root plastids readily utilize exogenously supplied ATP for fatty acid biosynthesis, these plastids can also synthesize sufficient ATP when provided with the appropriate cofactors.

Kleppinger-Sparace, Kathryn F.; Stahl, Richard J.; Sparace, Salvatore A.

1992-01-01

441

[Clinical application of testing methods on acid-fast bacteria].  

PubMed

Clinical bacteriology pertaining to acid-fast bacteria has made marked advances over the past decade, initiated by the development of a DNA probe kit for identification of acid-fast bacteria. Wide-spread use of nucleic acid amplification for rapid detection of tubercle bacillus contributed more greatly than any other factor to such advances in this field. At present, 90% of all kits used for nucleic acid amplification in the world are consumed in Japan. Unfortunately, not a few clinicians in Japan have a false idea that the smear method and nucleic acid amplification are necessary but culture is not. In any event nucleic acid amplification has exerted significant impacts on the routine works at bacteriology laboratories. Among others, collecting bacteria by pretreatment with NALC-NaOH has simplified the introduction of the collective mode smear method and liquid media. Furthermore, as clinicians have become increasingly more experienced with various methods of molecular biology, it now seems possible to apply these techniques for detection of genes encoding drug resistance and for utilization of molecular epidemiology in routine laboratory works. Meanwhile, attempts to diagnose acid-fast bacteriosis by checking blood for antibody have also been made, primarily in Japan. At present, two kits for detecting antibodies to glycolipids (LAM, TDM, etc.) are covered by national health insurance in Japan. We have an impression that in Japan clinicians do not have adequate knowledge and skill to make full use of these new testing methods clinically. We, as the chairmen of this symposium, hope that this symposium will help clinicians increase their skill related to new testing methods, eventually leading to stimulation of advances in clinical practices related to acid-fast bacteria in Japan. 1. Smear microscopy by concentration method and broth culture system: Kazunari TSUYUGUCHI (Clinical Research Center, National Hospital Organization Kinki-chuo Chest Medical Center) Smear microscopy and culture still remain the cornerstone to diagnose tuberculosis. However, the classical methods in Japan using direct microscopy and Ogawa solid media were not sufficient for clinical use. In recent years substantial advance has been made in these fields. Concentration of clinical samples by centrifugation improves the sensitivity of smear microscopy with excellent reproducibility. The Mycobacteria Growth Indicator Tube (MGIT) system using liquid media yields high sensitivity and rapidity. Using these methods, more and more tuberculosis cases would be correctly diagnosed and treated adequately based on drug susceptibility testing. 2. New technologies for anti-tuberculosis drug susceptibility testing: Satoshi MITARAI (Bacteriology Division, Reference Centre for Mycobacterium, Research Institute of Tuberculosis, Japan Anti-Tuberculosis Association) Several new technologies have been developed to obtain anti-tuberculosis drug susceptibility testing (AST) results rapidly, utilising liquid culture and molecular technologies. Mycobacterium Growth Indicator Tube (MGIT), as a popular liquid culturing and AST system, was evaluated for its accuracy and usefulness. As for isoniazid, MGIT showed 12.6% of discordant result comparing with standard method. These MGIT resistant and Ogawa susceptible strains had relatively high MICs ranging 0.13 to 2.0 microg/ml. The molecular detection of resistant gene mutation is also a useful method to estimate drug resistance rapidly. The rpoB mutation detection is reliable with high sensitivity and specificity. 3. Nucleic acid amplification and novel diagnostic methods: Shunji TAKAKURA (Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine) Sensitivities of nucleic acid amplification tests (NAATs) for the diagnosis of tuberculosis meet clinical requirement that patients with high-risk of transmission should be identified within a day. Comparison of the performance of various NAATs is difficult because of the difference in sample processing and in samples tested among methods and reports. Con

Ichiyama, Satoshi; Suzuki, Katsuhiro

2005-02-01