scholarly journals Development of a reliable and easy method for screening Oenococcus carbohydrate consumption profile

OENO One ◽  
2010 ◽  
Vol 44 (1) ◽  
pp. 31 ◽  
Author(s):  
B. Hocine ◽  
Zohra Jamal ◽  
Laurent Riquier ◽  
Aline Lonvaud-Funel ◽  
Marguerite Dols-Lafargue
Keyword(s):  
Bacterial Growth ◽  
Hplc Analysis ◽  
Malolactic Fermentation ◽  
Inoculum Size ◽  
Bromocresol Green ◽  
Easy Method ◽  
Carbohydrate Consumption ◽  
Colorimetric Test ◽  
Malic Acid Degradation ◽  
Consumption Profile

<p style="text-align: justify;"><strong>Aims</strong>: The aim of this study was to develop a colorimetric test to determine <em>Oenococcus</em> carbohydrate consumption profile.</p><p style="text-align: justify;"><strong>Methods and results</strong>: A semi-defined growth medium which enabled efficient bacterial growth and medium acidification in the presence of glucose was developed. The inoculum size and the presence of citrate in the medium were optimized. Acidification of the medium was revealed by adding bromocresol green and was shown to be perfectly correlated with D-glucose, D-fructose, L-arabinose, D-xylose, L-rhamnose, D-cellobiose or D-trehalose consumption by 23 distinct <em>O. oeni</em> strains and one <em>O. kitaharae</em> strain (confirmed with HPLC analysis).</p><p style="text-align: justify;"><strong>Significance and impact of the study</strong>: Efficient bacterial growth is essential before malic acid degradation occurs in wine. The method developed here will facilitate the comparison of numerous <em>O. oeni</em> strains and their ability to grow by using the various carbohydrates present in wine prior to malolactic fermentation.</p>

scholarly journals Production of thermostable extracellular α-amylase by a moderate thermophilic Bacillus licheniformis isolated from Qinarje Hot Spring (Ardebil prov. of Iran)

2017 ◽  
Vol 118 (4) ◽  
Author(s):  
Ali Deljou ◽  
Iman Arezi
Keyword(s):  
Carbon Source ◽  
Nitrogen Source ◽  
Bacillus Licheniformis ◽  
Bacterial Growth ◽  
Enzyme Production ◽  
Hot Spring ◽  
Basal Medium ◽  
Thermophilic Bacterium ◽  
Inoculum Size ◽  
Amylase Production

Background and Purpose: Amylases are most important industrial enzymes that account for about 30% of the world’s food, feed, fermentation, textile, detergent and cellulosic industries. This study aimed at optimum production of thermostable α-amylase via moderate thermophilic bacterium (Bacillus licheniformis) which was recently isolated from Qinarje Hot spring.Material and Methods: Initially, ability of bacterium for amylase activity was determined by starch hydrolysis test using Gram’s iodine staining. Then bacterial growth pattern and amylase production curves in basal production medium were graphically determined at different time intervals. Finally, effect of different temperature, pH, carbon source, nitrogen source, minerals and inoculum size were studied on bacterial growth and amylase production using turbidimetric and DNS method, respectively.Results: Optimum enzyme production achieved after 84 hours of inoculation from cultures growing at 40 ˚C and pH 9.0 in a medium containing 0.03% (w/v) of CaCl2, compared to the basal medium, results showed that the best enzyme production happened with inoculum size of 4% (v/v). The addition of 1% (w/v) rice husk (as a Carbon source) enhanced enzyme productivity up to 160% and substitution of the peptone and yeast extract with 1% (w/v) of tryptone (as a Nitrogen source) increased the α-amylase production up to 160%.Conclusion: Our findings show that B. licheniformis-AZ2 strain has an ability to produce the thermostable α-amylase which is suitable in starch processing and food industries. To be commercialized, further investigation is required for enhancement of the enzyme production.Keywords: Bacillus licheniformis; Optimization; Basal medium; Agricultural by-products.

scholarly journals The oenological interest of fumaric acid: Stop malolactic fermentation and preserve the freshness of wines

2019 ◽  
Vol 15 ◽  
pp. 02034
Author(s):  
A. Morata ◽  
M.A. Bañuelos ◽  
C. López ◽  
S. Chenli ◽  
R. Vejarano ◽  
...  
Keyword(s):  
Fumaric Acid ◽  
Malic Acid ◽  
Acid Content ◽  
Red Wine ◽  
Bacterial Count ◽  
Malolactic Fermentation ◽  
Oenococcus Oeni ◽  
Bacterial Development ◽  
Malic Acid Degradation ◽  
Different Doses

One of the problems related to the increase in average temperatures in the wine-growing regions is the lower accumulation of organic acids in the berries. Wine freshness depends to a great extent on its acidity. Herein, the effectiveness of fumaric acid to inhibit malolactic fermentation or to stop it once initiated is evaluated in order to preserve the malic acid content. Different doses of fumaric acid and SO2 were tested. The ability of these compounds to inhibit bacterial development and stop the malic acid degradation was tested on a red wine of the variety Vitis vinifera L. cv. Tempranillo whose malic acid content was set at 1.5 g/L. The control wine inoculated with 6 log CFU/mL of Oenococcus oeni finished the malolactic fermentation in 12 days. However, the use of doses equal to or greater than 300 mg/L of fumaric acid delayed the onset of malolactic fermentation for more than 50 days with little degradation of malic acid. In addition, fumaric acid proved to be effective in stopping malolactic fermentation already started where the bacterial count was 7 log CFU/mL. Fumaric acid can be considered as a potent inhibitor of malolactic fermentation.

Inhibition of bacterial growth and malolactic fermentation in wine by bacteriophage

1986 ◽  
Vol 61 (4) ◽  
pp. 287-293 ◽  
Author(s):  
T. Henick-Kling ◽  
T. H. Lee ◽  
D. J. D. Nicholas
Keyword(s):  
Bacterial Growth ◽  
Malolactic Fermentation

Experimental Legionella longbeachae infection in intratracheally inoculated mice

2009 ◽  
Vol 58 (6) ◽  
pp. 723-730 ◽  
Author(s):  
Ivana Gobin ◽  
Milorad Susa ◽  
Gabrijela Begic ◽  
Elizabeth L. Hartland ◽  
Miljenko Doric
Keyword(s):  
Bacterial Growth ◽  
Early Phase ◽  
Inflammatory Process ◽  
Inflammatory Cells ◽  
Inoculum Size ◽  
High Morbidity ◽  
Histological Changes ◽  
Initial Inoculum ◽  
Lower Respiratory Disease ◽  
Kinetics Of

This study established an experimental model of replicative Legionella longbeachae infection in A/J mice. The animals were infected by intratracheal inoculation of 103–109 c.f.u. L. longbeachae serogroup 1 (USA clinical isolates D4968, D4969 and D4973). The inocula of 109, 108, 107 and 106 c.f.u. of all tested L. longbeachae serogroup 1 isolates were lethal for A/J mice. Inoculation of 105 c.f.u. L. longbeachae caused death in 90 % of the animals within 5 days, whilst inoculation of 104 c.f.u. caused sporadic death of mice. All animals that received 103 c.f.u. bacteria developed acute lower respiratory disease, but were able to clear Legionella from the lungs within 3 weeks. The kinetics of bacterial growth in the lungs was independent of inoculum size and reached a growth peak about 3 logarithms above the initial inoculum at 72 h after inoculation. The most prominent histological changes in the lungs were observed at 48–72 h after inoculation in the form of a focal, neutrophil-dominant, peribronchiolar infiltration. The inflammatory process did not progress towards the interstitial or alveolar spaces. Immunohistological analyses revealed L. longbeachae serogroup 1 during the early phase of infection near the bronchiolar epithelia and later co-localized with inflammatory cells. BALB/c and C57BL/6 mice strains were also susceptible to infection with all L. longbeachae serogroup 1 strains tested and very similar changes were observed in the lungs of infected animals. These results underline the infection potential of L. longbeachae serogroup 1, which is associated with high morbidity and lethality in mice.

scholarly journals Oenococcus oeni Lifestyle Modulates Wine Volatilome and Malolactic Fermentation Outcome

2021 ◽  
Vol 12 ◽  
Author(s):  
Rosanna Tofalo ◽  
Noemi Battistelli ◽  
Giorgia Perpetuini ◽  
Luca Valbonetti ◽  
Alessio Pio Rossetti ◽  
...  
Keyword(s):  
Malic Acid ◽  
Malolactic Fermentation ◽  
Oenococcus Oeni ◽  
Laser Scanning Microscopy ◽  
Aroma Compound ◽  
Confocal Laser ◽  
Wine Aroma ◽  
Acid Degradation ◽  
Malic Acid Degradation ◽  
Strain Dependent

In this study, nine Oenococcus oeni strains were tested for their ability to adhere to polystyrene using mMRS and wine as culture media. Moreover, planktonic and biofilm-detached cells were investigated for their influence on malic acid degradation kinetics and aroma compound production. Three strains were able to adhere on polystyrene plates in a strain-dependent way. In particular, MALOBACT-T1 and ISO359 strains mainly grew as planktonic cells, while the ISO360 strain was found prevalent in sessile state. The strain-dependent adhesion ability was confirmed by confocal laser scanning microscopy. Planktonic and biofilm detached cells showed a different metabolism. In fact, biofilm-detached cells had a better malic acid degradation kinetic and influenced the aroma composition of resulting wines, acting on the final concentration of esters, higher alcohols, and organic acids. Oenococcus oeni in biofilm lifestyle seems to be a suitable tool to improve malolactic fermentation outcome, and to contribute to wine aroma. The industrial-scale application of this strategy should be implemented to develop novel wine styles.

Stimulation de la fermentation malolactique par l'addition au vin d'enveloppes cellulaires de levure et différents adjuvants de nature polysaccharidique et azotée

OENO One ◽  
1985 ◽  
Vol 19 (4) ◽  
pp. 229 ◽  
Author(s):  
Aline Lonvaud-Funel ◽  
Catherine Desens ◽  
Annick Joyeux
Keyword(s):  
Fatty Acids ◽  
Yeast Extract ◽  
Malic Acid ◽  
Bacterial Population ◽  
Malolactic Fermentation ◽  
Yeast Metabolism ◽  
Acides Gras ◽  
Acid Degradation ◽  
Malic Acid Degradation

<p style="text-align: justify;">L'addition au vin d'écorces de levure (0,2 g par litre) permet une stimulation de la fermentation malolactique. Leur action s'exerce en augmentant la population bactérienne et surtout en retardant et atténuant la phase de déclin. Le traitement du vin par des polysaccharides (alginates, polysaccharides extraits de vin) ou par l'extrait de levure accelere aussi le processus de dégradation de l'acide malique. Ces adjuvants agissent probablement en limitant l'action inhibitrice de certains métabolites levuriens tels les acides gras.</p><p style="text-align: justify;">+++</p><p style="text-align: justify;">Addition of yeast ghosts to wine (0,2 g per liter) stimulates the malolactic fermentation. The bacterial population is increased furthermore the declin phase is delayed. Addition of polysaccharides to wine (alginate, polysaccharides extracted from wine) or yeast extract also accelerate the malic acid degradation. These additions probably limit the inhibition by some products of the yeast metabolism like fatty acids.</p>

scholarly journals Optimization of Liquid Medium for High Phosphate Solubilization by Serratia Marcescens Strain AGKT4

2017 ◽  
Vol 5 (12) ◽  
pp. 1626
Author(s):  
Mohd Yusoff Abd. Samad ◽  
Sulaiman Zulkefly ◽  
Monsuru Adekunle Salisu ◽  
Mohd Jaafar Ahmad Kamil
Keyword(s):  
Mathematical Model ◽  
Response Surface Methodology ◽  
Liquid Medium ◽  
Serratia Marcescens ◽  
Response Surface ◽  
Bacterial Growth ◽  
Phosphate Solubilization ◽  
Inoculum Size ◽  
Box Behnken Design ◽  
High Phosphate

This study is on the optimization of the medium for solubilization of phosphate based on the Box-Behnken design and response surface methodology. Optimization of the liquid medium for phosphate solubilization using Serratia marcescens strain AGKT4 was carried out by varying the concentrations of 3 ingredients; the fructose, peptone and inoculum size of bacteria. A mathematical model derived from the response surface methodology was then validated statistically for the target test variables. The highest phosphate solubilization in the medium was achieved at the optimal concentrations of fructose and peptone at 6% (w/v) and 0.6% (w/v), respectively. The maximum phosphate solubilization at these concentrations was 239.12 µg/mL. Under the same conditions, the bacterial growth in the medium was 9 log10 CFU.

A New Technique for the Light and Electron Microscopic Study of Individual Cerebro-Spinal Fluid Cells in a Mona Plane Layer

1976 ◽  
Vol 34 ◽  
pp. 362-363
Author(s):  
L.A. Dell
Keyword(s):  
Microscopic Study ◽  
Electron Microscopic Study ◽  
Plane Layer ◽  
Ultrastructural Level ◽  
Spinal Fluid ◽  
Electron Microscopic Level ◽  
Electron Microscopic ◽  
Easy Method ◽  
Cell Pellet ◽  
A New Technique

A new method has been developed which readily offers the microscopist a possibility for both light and electron microscopic study of selected cells from the cerebrospinal fluid. Previous attempts to examine these cells in the spinal fluid at the ultrastructural level were based on modifications of cell pellet techniques developed for peripheral blood. These earlier methods were limited in application by the number of cells in spinal fluid required to obtain a sufficient size pellet and by the lack of an easy method of cellular identification between the light and electron microscopic level. The newly developed method routinely employs microscope slides coated with Siliclad and tungsten oxide for duplicate cytocentrifuge preparations of diagnostic spinal fluid specimens. Work done by Kushida and Suzuki provided a basis for our use of the metal oxide.

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