scholarly journals A single change in the aptamer of the Lactiplantibacillus plantarum rib operon riboswitch severely impairs its regulatory activity and leads to a vitamin B 2 ‐ overproducing phenotype

Author(s):  
Inés Ripa ◽  
José Ángel Ruiz‐Masó ◽  
Nicola De Simone ◽  
Pasquale Russo ◽  
Giuseppe Spano ◽  
...  
2021 ◽  
Author(s):  
Inés Ripa ◽  
José Ángel Ruiz-Masó ◽  
Nicola De Simone ◽  
Pasquale Russo ◽  
Giuseppe Spano ◽  
...  

Manufacturing of probiotics and functional foods using lactic acid bacteria that overproduce vitamin B2 has gained growing interest due to ariboflavinosis problems affecting populations of both developing and affluent countries. Two isogenic Lactiplantibacillus plantarum strains, namely a riboflavin-producing parental strain (UFG9) and a roseoflavin-resistant strain (B2) that carries a mutation in the FMN-aptamer of the potential rib operon riboswitch, were analyzed for production and intra- and extracellular accumulation of flavins, as well as for regulation of the rib operon expression. Strain B2 accumulated in the medium one of the highest levels of riboflavin+FMN ever reported for lactic acid bacteria, exceeding by ~25 times those accumulated by UFG9. Inside the cells, concentration of FAD was similar in both strains, while that of riboflavin+FMN was ~6-fold higher in B2. Mutation B2 could decrease the stability of the aptamer's regulatory P1 helix even in the presence of the effector, thus promoting the antiterminator structure of the riboswitch ON state. Although the B2-mutant riboswitch showed an impaired regulatory activity, it retained partial functionality being still sensitive to the effector. The extraordinary capacity of strain B2 to produce riboflavine, together with its metabolic versatility and probiotic properties, can be exploited for manufacturing multifunctional foods.


2005 ◽  
Vol 62 (11) ◽  
pp. 713-718 ◽  
Author(s):  
Rudin

Erfolgreicher Schutz gegen Stiche von blutsaugenden Insekten und Zecken bedingt die konsequente Anwendung geeigneter Maßnahmen. Eine eventuell notwendige Chemoprophylaxe wird dadurch nie ersetzt. Die Umstände, unter denen der Schutz erreicht werden soll, bestimmen die Kombination der zu treffenden Maßnahmen. Von Wohnräumen kann man Insekten mit Mückengittern oder -gaze an Fenstern und Türen oder mittels Klimaanlagen fernhalten. Beim Schlafen kann man sich mit einem Moskitonetz schützen. Diese Maßnahmen können bei Bedarf durch Insektizide ergänzt oder unterstützt werden. Meistens kommen synthetische Pyrethroide entweder als «knock down»-Sprays oder elektroverdampft für die Behandlung von Räumen oder als Imprägnierungsmittel von Netzen und Gittern zum Einsatz. Wenn ein Kontakt nicht durch die Wahl von Aufenthaltsort und -zeit vermeidbar ist, werden außer Haus zum Schutz vor Stichen geeignete Kleidung sowie Repellentien eingesetzt. Kleider sollen möglichst viel Körperfläche bedecken, aus festem Gewebe, nicht eng anliegend und von heller Farbe sein. Eine zusätzliche Behandlung mit Insektiziden ist vorteilhaft. Repellentien werden direkt auf die Haut appliziert. Diethylmethylbenzamin (DEET) zeigt seit vielen Jahren eine verlässliche Wirkung. Ebenfalls verbreitete synthetische Wirkstoffe sind Bayrepel® und IR3535. Sie weisen ein noch etwas geringeres Nebenwirkungsrisiko auf, nachteilig ist jedoch die schwächere Wirkung. Von den pflanzlichen Produkten sind die mit einem Extrakt aus Eucalyptus citriodora die am besten wirksamen. Schwächere Produkte schützen Personen, die für Mücken speziell attraktiv sind, nur ungenügend. Völlig nutzlos sind auf Arm-, Halsbänder oder Kleber aufgetragene Repellentien, sowie Ultraschallgeräte, UV-Lichtfallen oder die Einnahme von Vitamin B1 oder Knoblauch.


2011 ◽  
Vol 81 (5) ◽  
pp. 328-334 ◽  
Author(s):  
Oya Halicioglu ◽  
Sezin Asik Akman ◽  
Sumer Sutcuoglu ◽  
Berna Atabay ◽  
Meral Turker ◽  
...  

Aim: Nutritional vitamin B12 deficiency in infants may occur because the maternal diet contains inadequate animal products. Clinical presentations of the infants who had nutritional vitamin B12 deficiency were analyzed in this study. Subjects and Methods: Patients with nutritional vitamin B12 deficiency were enrolled in the study between 2003 and 2010. The diagnosis was based on a nutritional history of mothers and infants, clinical findings, hematological evaluation, and low level of serum vitamin B12. Results: Thirty children aged 1 - 21 months constituted the study group. Poverty was the main cause of inadequate consumption of animal products of the mothers. All infants had predominantly breastfed. The most common symptoms were developmental delay, paleness, apathy, lethargy, anorexia, and failure to thrive. Hematological findings were megaloblastic anemia (83.3 %), thrombocytopenia (30 %), and severe anemia (13.3 %). All of the mothers had low serum B12 levels; eight of them had megaloblastic anemia. Conclusion: The unusual clinical manifestations of vitamin B12 deficiency may also be seen apart from neurological and hematological findings. Nutritional vitamin B12 deficiency due to maternal deficiency might be a serious health problem in infants. Therefore, screening and supplementation of pregnant and lactating women to prevent infantile vitamin B12 deficiency should be considered.


2008 ◽  
Vol 78 (2) ◽  
pp. 64-69 ◽  
Author(s):  
Choi ◽  
Cho

This study investigated the effect of vitamin B6 deficiency on the utilization and recuperation of stored fuel in physically trained rats. 48 rats were given either vitamin B6-deficient (B6–) diet or control (B6+) diet for 4 weeks and were trained on treadmill for 30 minutes daily. All animals were then subdivided into 3 groups: before-exercise (BE); during-exercise (DE); after-exercise (AE). The DE group was exercised on treadmill for 1 hour just before being sacrificed. Animals in the AE group were allowed to take a rest for 2 hours after being exercised like the DE group. Glucose and free fatty acids were compared in plasma. Glycogen and triglyceride were compared in liver and skeletal muscle. Protein levels were compared in plasma, liver, and skeletal muscle. Compared with the B6+ group, plasma glucose levels of the B6– group were significantly lower before and after exercise. Muscle glycogen levels of the B6– group were significantly lower than those of the B6+ group regardless of exercise. The liver glycogen level of the B6– group was also significantly lower than that of B6+ group during and after exercise. Before exercise, plasma free fatty acid levels were not significantly different between the B6+ and B6– groups, and plasma free fatty acid levels of the B6– group were significantly lower during and after exercise. The muscle triglyceride level of the B6– group was significantly lower than that of the B6+ group before exercise, and there were no differences between B6+ and B6– groups during and after exercise. Liver triglyceride levels were not significantly different between B6+ and B6– groups. Plasma protein levels of the B6– group were lower than those of B6+ before and after exercise. Muscle protein levels of the B6– group were not significantly different from those of the B6+ group. Liver protein levels of the B6– group were significantly lower than that of the B6+ group after exercise. Liver protein levels of both B6+ and B6– groups were not significantly changed, regardless of exercise. Thus, it is suggested that vitamin B6 deficiency may reduce fuel storage and utilization with exercise in physically trained rats.


2015 ◽  
Vol 85 (3-4) ◽  
pp. 202-210 ◽  
Author(s):  
Ivona Višekruna ◽  
Ivana Rumbak ◽  
Ivana Rumora Samarin ◽  
Irena Keser ◽  
Jasmina Ranilović

Abstract. Results of epidemiologic studies and clinical trials have shown that subjects following the Mediterranean diet had lower inflammatory markers such as homocysteine (Hcy). Therefore, the aim of this cross-sectional study was to assess female diet quality with the Mediterranean diet quality index (MDQI) and to determine the correlation between MDQI, homocysteine, folate and vitamin B12 levels in the blood. The study participants were 237 apparently healthy women (96 of reproductive age and 141 postmenopausal) between 25 and 93 years. For each participant, 24-hour dietary recalls for 3 days were collected, MDQI was calculated, and plasma Hcy, serum and erythrocyte folate and vitamin B12 levels were analysed. Total MDQI ranged from 8 to 10 points, which represented a medium-poor diet for the subjects. The strength of correlation using biomarkers, regardless of group type, age, gender and other measured parameters, was ranked from best (0.11) to worst (0.52) for olive oil, fish, fruits and vegetables, grains, and meat, in this order. Hcy levels showed the best response among all markers across all groups and food types. Our study shows significant differences between variables of the MDQI and Hcy levels compared to levels of folate and vitamin B12 in participants with medium-poor diet quality, as evaluated according to MDQI scores.


2009 ◽  
Vol 79 (56) ◽  
pp. 297-307 ◽  
Author(s):  
Laila Hussein ◽  
Sahar Abdel Aziz ◽  
Salwa Tapouzada ◽  
Boehles

Objective:Cobalamin (B12) deficiency has been reported in infants born to mothers with low cobalamin intake. Early diagnosis of vitamin B12 deficiency in infants is critical for the prevention of neurobehavioral disorders. We investigated the relationship between serum vitamin B12 level in newborns and in their healthy mothers who consumed an omnivorous diet. Anthropometry was studied longitudinally to assess the growth velocity of the infants. Urinary methylmalonic acid (MMA) excretion of 6-month old infants was compared retrospectively as the biomarker correlated with the initial serum vitamin B12 concentrations. Methods: Serum cobalamin and blood hemoglobin were determined in 84 pairs of newborns and their mothers. Urinary MMA excretion was measured in the same subjects during the first 6 months of the post partum period. Results: At birth, median serum cobalamin levels were 152.0 pmol/L in the mothers and 296.6 pmol/L in the newborns. Maternal and neonatal serum cobalamin levels had no effect on growth velocity during the first six months of postnatal life. Serum maternal and neonatal cobalamin levels were inversely associated with urinary MMA excretion. Conclusion: Early diagnosis of vitamin B12 status in neonates and infants is crucial, particularly in nutritionally deprived areas. Biochemical measurement of plasma cobalamin or its metabolic marker MMA is highly recommended. Urinary MMA measurement in cobalamin diagnostics provides an advantage in that blood sampling is not required. A vitamin B12 taskforce should be created to alleviate vitamin deficiency and its negative consequences.


2012 ◽  
Vol 82 (4) ◽  
pp. 260-266 ◽  
Author(s):  
Salah E. Gariballa ◽  
Sarah J. Forster ◽  
Hilary J. Powers

Background: Although a number of studies have reported raised total plasma homocysteine (tHcy) concentrations in free-living older people, there are no data on homocysteine response to a mixed nutrient supplement in older patients. A raised plasma homocysteine concentration in older patients is partly a reflection of their co-morbidity, including impaired renal function, and there is uncertainty about the extent to which dietary interventions can improve plasma tHcy. Aim: To determine the plasma tHcy response to dietary supplements during acute illness. Methods: Two-hundred and thirty-six hospitalized, acutely ill older patients, who were part of a randomized double-blind placebo-controlled trial, were assigned to receive a daily oral nutritional supplement drink containing 1.3 mg of vitamin B2, 1.4 mg of vitamin B6, 1.5 μg of B12, 200 μg of folic acid, or a placebo, for 6 weeks. Outcome measures were plasma tHcy concentration at baseline, 6 weeks, and 6 months. Results: The mean plasma tHcy concentration fell among patients given the supplements (mean difference 4.1 µmol/L [95 % C.I, 0.14 to 8.03), p = 0.043], but tHcy concentration increased between 6 weeks and 6 months, after patients stopped taking the supplements [mean difference -2.0 µmol/L (95 % C.I, -03.9 to -0.18), p = 0.033]. About 46 % of patients in the placebo group and 55 % of patients in the supplement group had hyperhomocysteinemia (>14 µmol/L) at baseline compared with 45 % and 29 % at the end of the treatment period. Conclusions: A mixed nutrient supplement containing physiological amounts of B vitamins significantly reduced plasma tHcy concentrations in older patients recovering from acute illness.


2006 ◽  
Vol 210 (S 5) ◽  
Author(s):  
N Haiden ◽  
K Klebermass ◽  
F Cardona ◽  
J Schwindt ◽  
A Berger ◽  
...  

2006 ◽  
Vol 210 (S 5) ◽  
Author(s):  
N Haiden ◽  
K Klebermass ◽  
F Cardona ◽  
J Schwindt ◽  
A Berger ◽  
...  

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