Growth Of Leuconostoc Mesenteroides Research Articles

Bacteremia by Leuconostoc mesenteroides in an immunocompetent patient with chronic Chagas disease: a case report

BackgroundThe Leuconostoc mesenteroides are members of the Streptococcae family and currently has been recognized as potential pathogens. This case describes a bacteremia caused by L. mesenteroides in an immunocompetent patient affected by Chagas disease.Case presentationA 67-year-old female patient with chagasic megaesophagus and megacolon was submitted to a Heller myotomy for achalasia in 2000 and endoscopic dilatation in 2015. Patient was admitted to the Nutrology Ward in May 2016 with protein-calorie malnutrition associated with achalasia and receiving enteral nutrition. In July 2016, the patient underwent a Serra-Doria surgery. In the third postoperative day she presented an important abdominal distension. She was submitted to a new surgical intervention, and then a terminal ileum perforation was detected, leading the surgeon to perform an enterectomy with side-to-side anastomosis. The next day after the surgery (4th postoperative day) the patient presented a decreased level of consciousness (Glasgow coma scale = 8), hypotension and hypoxemia. In two samples of blood cultures there was growth of Leuconostoc mesenteroides. Susceptibility pattern was evaluated by the diffusion disk method. The microorganism was susceptible to penicillin, ampicillin, chloramphenicol, erythromycin, and fluoroquinolones, but resistant to rifampin, tetracycline, vancomycin and teicoplanin.ConclusionWe concluded that infections caused by L. mesenteroides is serious and should be considered not only in settings of immunosuppression and prolonged antimicrobial use, but also in immunocompetent patients undergoing surgeries involving the gastrointestinal tract.

Effect of Initial Headspace O2 Level on the Growth and Volatile Metabolite Production of Leuconostoc Mesenteriodes and the Microbial and Sensorial Quality of Modified Atmosphere Packaged Par-Fried French Fries.

This study evaluated the effect of residual O2 level (0% to 5%) on microbial growth and volatile metabolite production on par-fried French fries packaged in a modified atmosphere with 60% CO2 (rest N2 ) at 4 °C. The results obtained showed that the initial headspace (IH) O2 level had an effect on growth of Leuconostoc mesenteroides on French fry simulation agar, whereby growth was slightly faster under 5% O2 . In terms of quantity, ethanol, 2-methyl-1-propanol, and dimethyl disulphide were the most significant volatile metabolites produced by L. mesenteroides. The production of ethanol by L. mesenteroides was highest on simulation agar packaged under low IH O2 levels (0% to 1%), indicating that the fermentative metabolism was induced under these conditions. In agreement with the results observed on the simulation medium, growth of native lactic acid bacteria was faster under an IH O2 level of 5%. In addition, ethanol, 2-methyl-1-propanol, and dimethyl disulphide were also quantitatively the most important volatile metabolites. However, in contrast, greater quantities of ethanol and dimethyl disulphide were produced on par-fried French fries packaged under 5% O2 . This was attributed to the limited growth of the native flora on the par-fried French fries under residual O2 levels of 0% and 1%. Although some significant differences (P < 0.05) occurred between the French fries packaged in 0%, 1%, and 5 % residual O2 during storage, all products were considered to be acceptable for consumption. The results of this study can be used to optimize the shelf-life of packaged chill stored potato products.

Influence of temperature and pH on production of two bacteriocins by Leuconostoc mesenteroides subsp. mesenteroides FR52 during batch fermentation.

The influence of temperature and pH on growth of Leuconostoc mesenteroides subsp. mesenteroides FR52 and production of its two bacteriocins, mesenterocin 52A and mesenterocin 52B, was studied during batch fermentation. Temperature and pH had a strong influence on the production of the two bacteriocins which was stimulated by slow growth rates. The optimal temperature was 20 degrees C for production of mesenterocin 52A and 25 degrees C for mesenterocin 52B. Optimal pH values were 5.5 and 5.0 for production of mesenterocin 52A and mesenterocin 52B respectively. Thus, by changing the culture conditions, production of one bacteriocin can be favoured in relation to the other. The relationship between growth and specific production rates of the two bacteriocins, as a function of the culture conditions, showed different kinetics of production and the presence of several peaks in the specific production rates during growth.

Nutritional requirements of Leuconostoc mesenteroides subsp. mesenteroides and subsp. dextranicum for growth in milk

Growth of Leuconostoc mesenteroides in milk was studied with respect to the proteinase and peptidase activities of the strains and their nutritional requirements. Ln. mesenteroides grew poorly in milk since none of the 14 strains studied exceeded 5×108 cfu/ml at the end of growth. Few strains displayed proteinase activity, and this did not contribute much to growth. The pattern of peptidase activities varied with the strain. Nitrogen starvation and a high requirement for Mn2+ were involved in the cause of growth deficiencies. Addition of amino acids, 50 mg Mg2+/l and 0·08–0·49 mg Mn2+/l stimulated growth of most leuconostoc strains up to 5×108 cfu/ml. Addition of 5 g glucose/l to milk containing amino acids, Mg2+ and Mn2+ or yeast extract stimulated the growth of seven and eight strains respectively up to 109 cfu/ml. No growth advantage was found in a N2 atmosphere. However, the addition of small amounts of Mn2+ to milk suppressed the inhibitory effect of aeration on the growth of Ln. mesenteroides UD23, suggesting a protective role of Mn2+ against O2 toxicity.

Starter Culture Characterization by Conductance Methods

Activity tests using conductance methodologies have been developed for three important bacterial groups in mixed-strain DL-lactococcal starter culture. When cultures are grown in reconstituted skim milk and measured with the Malthus® instrument, the change in conductance was due to the growth of Lactococcus lactis ssp. lactis with Lactococcus lactis ssp. cremoris. Lactococcus lactis ssp. lactis biovar. diacetylactis gave a similar signal but normally is much less prevalent in the culture than the L. lactis ssp. cremoris and L. lactis ssp. lactis. In reconstituted skim milk containing .15% yeast extract and .14 g/ L of MnSO4, the growth of Leuconostoc mesenteroides ssp. cremoris was stimulated. In the same substrate supplemented with 200μg/ml of vancomycin, the growth of L. lactis ssp. lactis, L. lactis ssp. cremoris, and L. lactis ssp. lactis biovar. diacetylactis was totally inhibited, but the growth of Leuconostoc was unaffected. The capacity of the cultures to produce CO2 was analyzed in reconstituted skim milk containing .15% yeast extract, .14g/L MnSO4, and .5% sodium citrate by an indirect conductance method using a Rabit® instrument. In this substrate, the change in conductance was due to the growth of L. lactis ssp. lactis biovar. diacetylactis.

Inhibitory and stimulatory effects of cumin, oregano and their essential oils on growth and acid production of Lactobacillus plantarum and Leuconostoc mesenteroides

Cumin at concentrations of 0.5, 1.0 and 2.0 % (w/w) stimulated growth and acid production of Lactobacillus plantarum and Leuconostoc mesenteroides in a liquid medium. Essential oil from cumin at high concentrations (300 and 600 ppm) inhibited growth and acid production of Lactobacillus plantarum. After a certain period, growth of Leuconostoc mesenteroides was observed at all concentrations (150, 300 and 600 ppm) and its acid production was stimulated at 600 ppm. Oregano and its essential oil at all concentrations inhibited growth of both cultures. Acid production by Lactobacillus plantarum was stimulated by oregano spice.

Hypercapsulated growth of Leuconostoc mesenteroides in the sphacelial stage of Claviceps purpurea.

The occurrence in rye florets of an unusual saprophytic growth ofLeuconostoc mesenteroides in the honeydew of the sphacelial stage ofClaviceps purpurea is described. The bacterial infection prevents the further development of ergot sclerotia by interposing hypercapsulated cells in the floral cavity at the base of the ergotised ovary. The capsular material has been identified as the α 1–6 linked glucosan, dextran, and the bacterial growth form has been reproduced artificially in vivo.Saccharomyces kluyveri has been isolated from a naturally occurringL. mesenteroides growth.

Effect of Derivatives of L-Cysteine on Growth of Leuconostoc mesenteroides (8042)

IN the course of work on the chelating properties of certain amino-acid derivatives reaction products of cysteine with eight different aldehydes were prepared. The compounds were probably derivatives of thiazolidine-4-carboxylic acid1–3. They were prepared by previously described methods of synthesis or modifications of such methods4–6. In Table 1 the compounds are named simply by adding the name of the aldehyde to cysteine.

Effect of 4-methyl-2-thiouracil on growth of leuconostoc mesenteroides

The effect of the goitrogen 4-methyl-2-thiouracil in concentrations of 50—2,000 μg./10 ml. medium on growth ofL. mesenteroides was studied. This substance has an inhibitory effect on growth ofL. mesenteroides only in media containing pyridoxine. Its effect is related to the concentration and to the presence of pyridoxine. A high pyridoxine concentration (5.0 μg. /10 ml. medium) markedly reduces the effect of even 2,000 μg. 4-methyl-2-thiouracil/10 ml. medium. Inhibition of growth ofL. mesenteroides by 4-methyl-2-thiouracil is abolished competitively by thymine, and non-competitively by thymidine and folie acid up to concentrations of 1,000 μg. 4-methyl-2-thiouracil/10 ml. medium.

Utilization of glutamine and asparagine and their peptides by micro-organisms.

ALTHOUGH the utilization of asparagine and glutamine by micro-organisms has been studied in recent years, nothing is known about the metabolism of their simple peptides. Aspartic acid can support optimal growth of Leuconostoc mesen-teroides; but asparagine is utilized only to a small extent1,2. It has recently been found in this laboratory that the utilization of asparaginylglycine and glycylasparagine approximates that of the free di-carboxylic acid, and is better by far than that of asparagine2. The same was found to be true for Lactobacillus arabinosus under conditions of incubation that precluded the endogenous synthesis of aspartate (26° in vacuo over potassium hydroxide or 39°)3. On the other hand, glycylglutamine and glutaminylglycine replace glutamine molecule for molecule in the metabolism of L. arabinosus, and the organism grows in synthetic media containing the peptides or the free amide without the lag period characteristic of its growth in media containing glutamic acid. It has been shown previously that the sulphoxide derived from methionine competitively inhibits the utilization of glutamic acid, but has no effect on the utilization of glutamine4. In this respect, too, the glutamine peptides behave exactly as the free amide2.

Effect of derivatives of L-cysteine on the growth of Leuconostoc mesenteroides P-60.

Summary1. Alliin and L-cystine disulfoxide stimulated the growth of Leuconostoc mesenteroides but to a lesser degree than L-cystine. 2. Substitution of the sulfur hydrogen of L-cysteine by alkyl and alkene radicals did not produce any observable response. The sulfoxide of S-ethyl-L-cysteine was also inactive; however, S-propyl-L-cysteine sulfoxide was found to have a very slight activity. 3. The activity of alliin may be due to both the presence of the sulfoxide group and the unsaturation in the allyl radical.

Inhibition of the growth of Leuconostoc mesenteroides by the toxic factor from "agenized" zein: reversal by l-glutamine.

THE crystalline toxic factor originally isolated1 from zein treated with nitrogen trichloride causes epileptiform fits in certain animals and inhibits the growth of Leuconostoc mesenteroides P-602. The subsequent synthesis of the factor from methionine, reported3 from this laboratory, indicates that it probably has the structure CH3.SO(NH).CH2.CH2.CH(NH2)COOH which, formally, has some resemblance to that of glutamine.