The accumulation of phenolic acids and coproporphyrin by iron-deficient cultures of Bacillus subtilis

1970 ◽  
Vol 16 (12) ◽  
pp. 1179-1185 ◽  
Author(s):  
W. J. Peters ◽  
R. A. J. Warren

Phenolic acids started to accumulate before coproporphyrin in cultures of B. subtilis grown under conditions of iron deficiency. If hemin synthesis was reduced or prevented, both phenolic acid accumulation and the iron-uptake capacity of the cells were decreased. A mutant strain unable to synthesize hemin accumulated phenolic acids only if the culture medium was extracted with hydroxyquinoline to remove residual iron. A mixture of iron and 2,3-dihydroxybenzoic acid was more effective than iron alone in reducing coproporphyrin accumulation by iron-deficient cultures. It is suggested that phenolic acids are produced by B. subtilis to solubilize the iron in the medium; under iron deficiency the biosynthetic pathway for phenolic acids is derepressed so that residual iron in the medium will be made available to the cell as the phenolic acid: iron complex.

1971 ◽  
Vol 17 (1) ◽  
pp. 53-59 ◽  
Author(s):  
B. L. Walsh ◽  
W. J. Peters ◽  
R. A. J. Warren

Formation of the enzymes synthesizing 2,3-dihydroxybenzoic acid (DHB) in Bacillus subtilis is repressed by iron. DHB does not appear to be involved in regulating its own biosynthesis. Hemin may be involved in regulating DHB synthesis. DHB synthetase is inhibited by several m-substituted benzoic acids. The inhibitors do not affect the growth rate of B. subtilis and DHB appears not to be necessary for growth under the conditions used. Inhibition of DHB synthesis during growth under iron-deficient conditions reduces the iron uptake capacity of B. subtilis.


1970 ◽  
Vol 16 (12) ◽  
pp. 1285-1291 ◽  
Author(s):  
W. J. Peters ◽  
R. A. J. Warren

A variety of phenolic compounds and hydroxamic acids reduced or prevented phenolic acid and coproporphyrin accumulation by iron-deficient cultures of Bacillus subtilis, but only if they were added to cultures with levels of iron which alone did not prevent accumulation. The compounds also increased iron uptake by iron-deficient cultures and norma) cultures. When radioactive catechol or 2,3-dihydroxybenzoic acid was used to increase iron uptake by iron-deficient cells, only very low levels of radioactivity remained associated with the cells. It is suggested that B. subtilis produces phenolic acids to solubilize iron; that other phenolic compounds or hydroxamic acids may substitute for the phenolic acids produced by B. subtilis; that the iron: phenolic acid complex does not enter the cell; and that the iron is removed from the complex at the cell surface and taken into the cell by an energy-dependent active transport system.


2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Yangyun Zhou ◽  
Wei Sun ◽  
Junfeng Chen ◽  
Hexin Tan ◽  
Ying Xiao ◽  
...  

Abstract Salvia miltiorrhiza Bunge, which contains tanshinones and phenolic acids as major classes of bioactive components, is one of the most widely used herbs in traditional Chinese medicine. Production of tanshinones and phenolic acids is enhanced by methyl jasmonate (MeJA). Transcription factor MYC2 is the switch of jasmontes signaling in plants. Here, we focused on two novel JA-inducible genes in S. miltiorrhiza, designated as SmMYC2a and SmMYC2b, which were localized in the nucleus. SmMYC2a and SmMYC2b were also discovered to interact with SmJAZ1 and SmJAZ2, implying that the two MYC2s might function as direct targets of JAZ proteins. Ectopic RNA interference (RNAi)-mediated knockdown experiments suggested that SmMYC2a/b affected multiple genes in tanshinone and phenolic acid biosynthetic pathway. Besides, the accumulation of tanshinones and phenolic acids was impaired by the loss of function in SmMYC2a/b. Meanwhile, SmMYC2a could bind with an E-box motif within SmHCT6 and SmCYP98A14 promoters, while SmMYC2b bound with an E-box motif within SmCYP98A14 promoter, through which the regulation of phenolic acid biosynthetic pathway might achieve. Together, these results suggest that SmMYC2a and SmMYC2b are JAZ-interacting transcription factors that positively regulate the biosynthesis of tanshinones and Sal B with similar but irreplaceable effects.


2017 ◽  
Vol 147 (12) ◽  
pp. 2297-2308 ◽  
Author(s):  
Michael J Wenger ◽  
Laura E Murray-Kolb ◽  
Julie EH Nevins ◽  
Sudha Venkatramanan ◽  
Gregory A Reinhart ◽  
...  

Abstract Background: Iron deficiency and iron deficiency anemia have been shown to have negative effects on aspects of perception, attention, and memory. Objective: The purpose of this investigation was to assess the extent to which increases in dietary iron consumption are related to improvements in behavioral measures of perceptual, attentional, and mnemonic function. Methods: Women were selected from a randomized, double-blind, controlled food-fortification trial involving ad libitum consumption of either a double-fortified salt (DFS) containing 47 mg potassium iodate/kg and 3.3 mg microencapsulated ferrous fumarate/g (1.1 mg elemental Fe/g) or a control iodized salt. Participants' blood iron status (primary outcomes) and cognitive functioning (secondary outcomes) were assessed at baseline and after 10 mo at endline. The study was performed on a tea plantation in the Darjeeling district of India. Participants (n = 126; 66% iron deficient and 49% anemic at baseline) were otherwise healthy women of reproductive age, 18–55 y. Results: Significant improvements were documented for iron status and for perceptual, attentional, and mnemonic function in the DFS group (percentage of variance accounted for: 16.5%) compared with the control group. In addition, the amount of change in perceptual and cognitive performance was significantly (P < 0.05) related to the amount of change in blood iron markers (mean percentage of variance accounted for: 16.0%) and baseline concentrations of blood iron markers (mean percentage of variance accounted for: 25.0%). Overall, there was evidence that the strongest effects of change in iron status were obtained for perceptual and low-level attentional function. Conclusion: DFS produced measurable and significant improvements in the perceptual, attentional, and mnemonic performance of Indian female tea pickers of reproductive age. This trial was registered at clinicaltrials.gov as NCT01032005.


2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Jinli Zhang ◽  
Yan Ding ◽  
Haizhou Dong ◽  
Hanxue Hou ◽  
Xiansheng Zhang

Phenolic acid profiles and antioxidant activities of outer bran, coarse bran, and shorts from blue, black, and purple wheat were analyzed. Phenolic acids were mainly in the bound form in pigmented wheat bran fractions. Phenolic acid content decreased in the order of outer bran, coarse bran, and shorts for the three pigmented wheat varieties. HPLC analysis of phenolic extracts demonstrated that the bound form of phenolic acids contained more ferulic, isoferulic, and p-coumaric acids compared to their free counterparts. Among the three pigmented wheat varieties, the bran fractions from blue wheat contained higher bound phenolic acids than the other two pigmented wheat bran fractions, except for purple coarse bran. The blue wheat outer bran had the highest total bound phenolic acid of 3458.71 μg/g while the purple wheat shorts had the lowest of 1730.71 μg/g. The contribution of bound phenolic acids to the total phenolic content and antioxidant activity was significantly higher than that of free phenolic acids. Blue wheat bran fractions had the highest radical scavenging activity against DPPH∙ while those of purple wheat gained the highest ABTS∙+ scavenging activity. High correlations were observed between TPC and radical scavenging capacities for DPPH and ABTS (R2>0.85, P<0.05).


1980 ◽  
Vol 239 (5) ◽  
pp. R377-R381 ◽  
Author(s):  
E. Dillman ◽  
C. Gale ◽  
W. Green ◽  
D. G. Johnson ◽  
B. Mackler ◽  
...  

Iron-deficient rats become hypothermic and have an excessive catecholamine response when exposed to an ambient temperature of 4 degrees C. This is not due to changes in body insulation, since thickness is unaltered, since differences persist after removal of hair, and since cutaneous vasoconstriction is intact. On the other hand, oxygen consumption of iron-deficient animals at 4 degrees C is reduced, 39 +/- 3 ml . kg-1 . min-1 compared to 63 +/- 2 in control animals. Thyroxine (T4) values at 4 degrees C were 4.34 +/- 0.20 microgram/dl sera as compared to control values of 3.6 +/- 0.32. Triiodothyronine (T3) values of iron-deficient animals in the cold were 48 +/- 6.8 ng/dl as compared to 72 +/- 5.6 in control animals. Treatment of iron-deficient animals with iron was shown to normalize the plasma T3 response at 4 degrees C within 6 days. Thyroidectomized iron-deficient animals injected with T3 did not show hypothermia at 4 degrees C, whereas thyroidectomized iron-deficient animals injected with T4 showed hypothermia, increased catecholamines, and decreased T3 levels as compared to non-iron-deficient animals similarly treated. It is proposed that iron deficiency impairs conversion of T4 to T3 and that this is primarily responsible for the hypothermia observed.


2021 ◽  
pp. 1-8
Author(s):  
Kriti Puri ◽  
Joseph A. Spinner ◽  
Jacquelyn M. Powers ◽  
Susan W. Denfield ◽  
Hari P. Tunuguntla ◽  
...  

Abstract Introduction: Iron deficiency is associated with worse outcomes in children and adults with systolic heart failure. While oral iron replacement has been shown to be ineffective in adults with heart failure, its efficacy in children with heart failure is unknown. We hypothesised that oral iron would be ineffective in replenishing iron stores in ≥50% of children with heart failure. Methods: We performed a single-centre retrospective cohort study of patients aged ≤21 years with systolic heart failure and iron deficiency who received oral iron between 01/2013 and 04/2019. Iron deficiency was defined as ≥2 of the following: serum iron <50 mcg/dL, serum ferritin <20 ng/mL, transferrin >300 ng/mL, transferrin saturation <15%. Iron studies and haematologic indices pre- and post-iron therapy were compared using paired-samples Wilcoxon test. Results: Fifty-one children with systolic heart failure and iron deficiency (median age 11 years, 49% female) met inclusion criteria. Heart failure aetiologies included cardiomyopathy (51%), congenital heart disease (37%), and history of heart transplantation with graft dysfunction (12%). Median dose of oral iron therapy was 2.9 mg/kg/day of elemental iron, prescribed for a median duration of 96 days. Follow-up iron testing was available for 20 patients, of whom 55% (11/20) remained iron deficient despite oral iron therapy. Conclusions: This is the first report on the efficacy of oral iron therapy in children with heart failure. Over half of the children with heart failure did not respond to oral iron and remained iron deficient.


2022 ◽  
Author(s):  
Amanda K. Barks ◽  
Montana M. Beeson ◽  
Timothy C. Hallstrom ◽  
Michael K. Georgieff ◽  
Phu V. Tran

Iron deficiency (ID) during neurodevelopment is associated with lasting cognitive and socioemotional deficits, and increased risk for neuropsychiatric disease throughout the lifespan. These neurophenotypical changes are underlain by gene dysregulation in the brain that outlasts the period of ID; however, the mechanisms by which ID establishes and maintains gene expression changes are incompletely understood. The epigenetic modification 5-hydroxymethylcytosine (5hmC), or DNA hydroxymethylation, is one candidate mechanism because of its dependence on iron-containing TET enzymes. The aim of the present study was to determine the effect of fetal-neonatal ID on regional brain TET activity, Tet expression, and 5hmC in the developing rat hippocampus and cerebellum, and to determine whether changes are reversible with dietary iron treatment. Timed pregnant Sprague-Dawley rats were fed iron deficient diet (ID; 4 mg/kg Fe) from gestational day (G)2 to generate iron deficient anemic (IDA) offspring. Control dams were fed iron sufficient diet (IS; 200 mg/kg Fe). At postnatal day (P)7, a subset of ID-fed litters was randomized to IS diet, generating treated IDA (TIDA) offspring. At P15, hippocampus and cerebellum were isolated for subsequent analysis. TET activity was quantified by ELISA from nuclear proteins. Expression of Tet1, Tet2, and Tet3 was quantified by qPCR from total RNA. Global %5hmC was quantified by ELISA from genomic DNA. ID increased DNA hydroxymethylation (p=0.0105), with a corresponding increase in TET activity (p<0.0001) and Tet3 expression (p<0.0001) in the P15 hippocampus. In contrast, ID reduced TET activity (p=0.0016) in the P15 cerebellum, with minimal effect on DNA hydroxymethylation. Neonatal dietary iron treatment resulted in partial normalization of these changes in both brain regions. These results demonstrate that the TET/DNA hydroxymethylation system is disrupted by developmental ID in a brain region-specific manner. Differential regional disruption of this epigenetic system may contribute to the lasting neural circuit dysfunction and neurobehavioral dysfunction associated with developmental ID.


1990 ◽  
Vol 45 (4) ◽  
pp. 552-556 ◽  
Author(s):  
K. Taraz ◽  
E. M. Schaffner ◽  
H. Budzikiewicz ◽  
H. Korth ◽  
G. Pulverer

In addition to phenazine, phenazine-1-carboxylic acid, phenazine-1,6-dicarboxylic acid and 2,9-dihydroxyphenazine-1-carboxylic acid a new compound, viz. 2,3,9-trihydroxyphenazine-1-carboxylic acid could be isolated from the culture medium of Pseudomonas fluorescens grown under iron deficiency with beryllium added to the culture medium. Its structure elucidation is described.


1993 ◽  
Vol 264 (4) ◽  
pp. E662-E667 ◽  
Author(s):  
J. K. Linderman ◽  
P. R. Dallman ◽  
R. E. Rodriguez ◽  
G. A. Brooks

To evaluate the hypothesis that lactate supply is essential to maintain euglycemia during iron deficiency, female Sprague-Dawley rats were assigned to iron-sufficient (50 mg Fe2+/kg diet, +Fe), or iron-deficient (15 mg Fe2+/kg diet, -Fe) dietary groups and were injected with a specific beta 2-adrenergic inhibitor, ICI 118,551 (1.0 mg/kg body wt). Rats were studied at rest or after 30 min of running at 13.4 m/min 0% grade. Dietary iron deficiency decreased hemoglobin concentration 38%, but resting arterial concentrations of glucose ([Glc]), lactate ([La]), or alanine ([Ala]) were unaffected. Administration of ICI 118,551 (beta 2-blockade) decreased [La] and [Glc] 52 and 32% in resting -Fe rats, respectively. beta 2-Blockade attenuated the exercise-induced rise in [La] and decreased [Glc] 31% in exercising -Fe rats. [Ala] were unaffected by iron deficiency or exercise but decreased 24 and 18% because of beta 2-blockade in resting and exercising +Fe rats. Iron deficiency depleted resting liver glycogen concentration 45%, with no additional effect of exercise or beta 2-blockade. beta-Blockade decreased arterial insulin and increased arterial glucagon concentrations in resting -Fe and +Fe rats. During exercise glucagon concentration increased significantly more in -Fe than +Fe rats. Decreased arterial [La] with a corresponding decrease in arterial [Glc] in response to beta 2-blockade support the contention that lactate supply is critical to maintenance of euglycemia in -Fe rats at rest and during exercise.


Sign in / Sign up

Export Citation Format

Share Document