Mn Supplementation Research Articles

Mineral Status of Sheep and Goats Grazing in the Arid Rangelands of Northern Kenya

2 Abstract: A study was conducted in dry and wet season to determine macro and micro mineral status of growing sheep and goats in arid rangelands of northern Kenya. Forty four, 22 each of sheep and goats (1-2 year old), randomly purchased from three herds/flocks in study area, were sacrificed for whole liver and 12th right and left ribs. Homogenized liver samples pooled from all the lobes and defatted bone ash from whole left and right 12th ribs were used for determination of Ca, P, Mg, Cu, Fe, Zn and Mn status. Liver mineral analysis, showed that in sheep Cu (303 vs. 184 mg/kg DM), Zn (94.1 vs. 83 mg/kg DM) and Mn (13.2 vs. 7.5 mg/kg DM) were higher (p<0.05) in wet than dry season. In goats, season had no effect on Cu (274.28 vs. 236 mg/kg DM) and Fe (183 vs. 171 mg/kg DM), but had significant influence on Zn (102 vs. 126 mg/kg DM) and Mn (13.6 vs. 6.8 mg/kg DM). Sheep grazing in different pastures showed variation (p<0.05) in hepatic Zn, Cu and Mn cont ents, while goat varied (p<0.05) in hepatic Cu, Fe and Mn concentration s. Rib analysis indicated that season had significant effect (p<0.05) on sheep and goats DFF% ash. The rib Ca (359 vs. 362 mg/g), P (157 vs. 147 mg/g) and Mg (9.56 vs. 8.54 mg/g) contents of sheep was not influenced by season and grazing area (p<0.05), whereas goats rib Ca (360 vs. 326 mg/g), P (142 vs. 165 mg/g) content was affected by season and grazing area (p<0.05), but Mg showed no seasonal variation. In the wet season, liver and bone tissue of sheep and goats indicated adequate body status of Ca, Mg, Cu, Zn, Fe and Mn. However, in the dry season, sheep showed deficient levels of Zn, goats in Cu, while both species suffered from low liver Mn and rib Zn reserves. With the exception of P which was marginal in all seasons, mineral deficiencies affected animals mostly in the dry season. The liver and rib bone of sheep and goats has demonstrated seasonal fluctuation in tissue mineral reserve. Evaluation of specific minerals in different periods and body pools can be useful in the diagnosis of mineral status of animals. It can be concluded that, sheep and goats would benefit from P, Cu, Zn and Mn supplementation, particularly in the dry season.

Effects of diets supplemented with zinc and manganese on performance and related parameters in laying hens‡

Iron is often found to be of excessive concentrations in laying hens' diets, which may cause antagonistic interactions with other minerals. This study was conducted to investigate how to supplement Zn and Mn in the diets without Fe supplementation. In experiment 1, 420 18-week Lohmann Brown layers were fed a basal diet or a basal diet supplemented with 30-0, 65-30 and 100-60 mg/kg of Zn and Mn, respectively. In experiment 2, 360 40-week Lohmann Brown layers were fed a basal diet or a basal diet supplemented with 15-0, 35-0 and 55-15 mg/kg of Mn and Zn, respectively. Minerals were supplemented in the form of sulfate. Egg production was improved by supplementing 30 mg/kg Zn or 65 mg/kg Zn in combination with 30 mg/kg Mn in experiment one. In experiment two, a significant reduction of egg performance occurred with 35 mg/kg Mn supplementation. Mn and/or Zn supplementation increased eggshell thickness in experiment one, and decreased yolk cholesterol in both experiments. Mn and/or Zn supplementation increased Zn and Mn excretion in both experiments. Serum growth hormone (GH), thyroxine (T(4) ), and insulin levels, or alkaline phosphatase (AP) activity were not affected by treatments; serum estrogen (E(2) ) and triiodothyronine (T(3) ) were different but there was no consistency by dietary treatments. This study demonstrates that 30 mg/kg supplemental Zn is necessary to obtain maximal egg production, and there seems to be no need to supply Mn in this type of diet.

Dietary manganese requirement of juvenile yellow catfish Pelteobagrus fulvidraco, and effects on whole body mineral composition and hepatic intermediary metabolism

The present study was conducted to determine dietary manganese (Mn) requirement for juvenile yellow catfish Pelteobagrus fulvidraco and evaluate the effect of dietary Mn levels on growth performance, whole body mineral composition and hepatic intermediary metabolism for this fish species. The six experimental diets were formulated to contain the graded levels of MnSO 4·H 2O (0, 3, 6, 12, 24 and 48 mg Mn kg − 1 diet, respectively), providing the actual dietary Mn values of 3.1 (control), 4.2, 5.3, 6.9, 12.0 and 19.5 mg kg − 1 diet, respectively. Each diet was assigned to three replicate groups of yellow catfish (initial body weight: 4.00 ± 0.08, means ± SD) for 8 weeks. Percent weight gain (WG) increased with increasing dietary Mn levels from 3.1 to 5.3 mg kg − 1 diet and then plateaued above these levels. The lowest protein efficiency ratio (PER), and the highest feed conversion rate (FCR) were observed in fish fed the control diet and showed no significant differences among the other treatments. Dietary Mn supplementation did not significantly influence moisture, protein and ash contents in whole body, but whole body lipid content was the lowest for fish fed the 12.0 and 19.5 mg Mn kg − 1 diets. Condition factor and hepatosomatic index were observed to be the highest for fish fed the control diet. For whole body mineral composition, increasing Mn content, and declining calcium, phosphorus and iron contents were observed in fish fed the diets containing increasing Mn levels. For hepatic enzymatic activities, the Mn-SOD activities were observed to be the highest in fish fed the diets containing 5.3 and 6.9 mg Mn kg − 1 , and the lowest for fish fed the control diet. Lactate dehydrogenase activity declined with increasing dietary Mn level from 3.1 to 5.3 mg kg − 1 diet, and then increased with dietary Mn level from 5.3 to 19.5 mg kg − 1 diet. Hepatic lipase activity was observed to be the highest for fish fed the diet containing 12.0 mg Mn kg − 1 and showed no significant differences among the treatments. Succinate dehydrogenase, malic dehydrogenase and lipoprotein lipase activities showed no significant differences among the treatments ( P > 0.05). Analysis by the broken-line regression of WG, PER and hepatic Mn-SOD activity indicated that the optimal dietary Mn requirements in juvenile yellow catfish were 5.5, 5.6 and 6.4 mg kg − 1 diet, respectively.

Manganese Regulates Manganese-Containing Superoxide Dismutase (MnSOD) Expression in the Primary Broiler Myocardial Cells

Previous studies showed that dietary manganese can increase the MnSOD mRNA expression in a dose-dependent manner in the heart of broilers. In order to explore the specific mechanism of the MnSOD expression induced by manganese, a model of MnSOD expression was developed with primary cultured broiler myocardial cells. The objective of the present study was to investigate whether the model was working or not and to determine how manganese affects the expression of the enzyme in broiler myocardial cells in vitro. In experiment 1, various amount of manganese (0, 0.25, 0.5, 1, 2, and 4mM) were added into the cultures for 24-h incubation to investigate MnSOD expression and for 0-, 6-, 12-, 24-, 36-, and 48-h incubation to measure the cell viability. In experiment 2, the most suitable Mn supplementation based on the results of experiment 1 was added into cultures for 6-, 12-, 24-, and 48-h incubation. The results showed that MnSOD mRNA, MnSOD protein, and MnSOD activity were induced by manganese in dose- and time-dependent manner. Manganese regulates MnSOD expression not only at transcriptional level but also at translational and/or posttranslational levels.

Dietary Manganese Modulates Expression of the Manganese-Containing Superoxide Dismutase Gene in Chickens1–3

To investigate the possible mechanism(s) by which dietary manganese (Mn) levels and sources modulate the expression of the manganese-containing superoxide dismutase (MnSOD) gene at both the transcriptional and translational levels, we used 432 8-d-old male broiler chicks in a 1 plus 4 × 2 design. Chickens were given either a diet without Mn supplementation [control (C)] or diets supplemented with 100 (optimal) or 200 (high) mg Mn/kg diet from inorganic Mn sulfate (I) or 3 organic complexes of Mn and amino acids with weak (W), moderate (M), or strong (S) chelation strength up to 21 d of age. Compared with C chicks, chicks fed Mn-supplemented diets had higher (P < 0.01) Mn concentrations, specificity protein 1 (Sp1) DNA-binding activities, MnSOD mRNA levels, MnSOD mRNA-binding protein (MnSOD-BP) RNA-binding activities, MnSOD protein concentrations, and MnSOD activities within heart tissue, but lower (P < 0.01) heart activating protein-2 (AP-2) DNA-binding activities. Chicks fed M diets had higher (P < 0.05) heart Mn concentrations, MnSOD mRNA levels, and MnSOD-BP RNA-binding activities compared with those fed the I and W diets and lower (P < 0.01) AP-2 DNA-binding activities than those fed other treatment diets. These results suggest that dietary Mn could modulate the expression of the MnSOD gene in broilers by altering Sp1 and AP-2 DNA-binding activities at the transcriptional level and enhancing MnSOD-BP RNA-binding activity at the translational level. Additionally, an organic Mn source with moderate chelation strength could be more effective than other Mn sources in activating MnSOD gene expression at both the transcriptional and translational levels.

Novel high-throughput assay to assess cellular manganese levels in a striatal cell line model of Huntington's disease confirms a deficit in manganese accumulation

In spite of the essentiality of manganese (Mn) as a trace element necessary for a variety of physiological processes, Mn in excess accumulates in the brain and has been associated with dysfunction and degeneration of the basal ganglia. Despite the high sensitivity, limited chemical interference, and multi-elemental advantages of traditional methods for measuring Mn levels, they lack the feasibility to assess Mn transport dynamics in a high-throughput manner. Our lab has previously reported decreased net Mn accumulation in a mutant striatal cell line model of Huntington's disease (STHdhQ111/Q111) relative to wild-type following Mn exposure. To evaluate Mn transport dynamics in these striatal cell lines, we have developed a high-throughput fluorescence-quenching extraction assay (Cellular Fura-2 Manganese Extraction Assay – CFMEA). CFMEA utilizes changes in fura-2 fluorescence upon excitation at 360nm (Ca2+ isosbestic point) and emission at 535nm, as an indirect measurement of total cellular Mn content. Here, we report the establishment, development, and application of CFMEA. Specifically, we evaluate critical extraction and assay conditions (e.g. extraction buffer, temperature, and fura-2 concentration) required for efficient extraction and quantitative detection of cellular Mn from cultured cells. Mn concentrations can be derived from quenching of fura-2 fluorescence with standard curves based on saturation one-site specific binding kinetics. Importantly, we show that extracted calcium and magnesium concentrations below 10μM have negligible influence on measurements of Mn by fura-2. CFMEA is able to accurately measure extracted Mn levels from cultured striatal cells over a range of at least 0.1–10μM. We have used two independent Mn supplementation approaches to validate the quantitative accuracy of CFMEA over a 0–200μM cellular Mn-exposure range. Finally, we have utilized CFMEA to experimentally confirm a deficit in net Mn accumulation in the mutant HD striatal cell line versus wild-type cells. To conclude, we have developed and applied a novel assay to assess Mn transport dynamics in cultured striatal cell lines. CFMEA provides a rapid means of evaluating Mn transport kinetics in cellular toxicity and disease models.

An Estimation of the Manganese Requirement for Broilers from 1 to 21 Days of Age

A dose-response experiment was conducted to find the sensitive and consistent biomarker for the estimation of dietary manganese (Mn) requirement and establish the optimal Mn level for broilers fed a practical corn-soybean meal diet from 1 to 21days of age post-hatching. A total of 480 1-day-old Arbor Acres male chicks were randomly allotted to one of eight treatments with five replicates of 12 birds each and fed diets supplemented with 0, 20, 40, 60, 80, 100, 120, or 140mg Mn/kg from reagent grade Mn sulfate. Tissue Mn concentrations, manganese-containing superoxide dismutase (MnSOD) activity, and MnSOD mRNA concentration within heart tissue were analyzed at 7, 14, and 21days of age. Tissue Mn concentrations and heart MnSOD activity showed significant quadratic responses, and heart MnSOD mRNA concentration showed an asymptotic response to dietary supplemental Mn level, respectively. The estimate of dietary Mn for chicks from 1 to 21days of age was 122-128 for heart Mn concentration, 141-159 for pancreas Mn concentration, 127-138 for liver Mn concentration, and 135-156mg/kg for heart MnSOD activity, respectively. Heart MnSOD mRNA concentration was a consistent index for the estimation of the Mn requirement of broilers. Based on this index, the estimate of dietary Mn requirement for broilers from 1 to 21days of age post-hatching was about 130mg/kg, which was a little more than two times of the current NRC (1994) requirement.

Effect of dietary supplementation of trace elements on blood chemistry and selected immunological indices depending on the age of broiler chickens

This study was performed to determine the effects of dietary supplementation of Cu, Zn, Fe, Mn and Se on some haematological, immunological and enzymatic indices in blood of broilers at the age of 21, 35 and 42 days. The basal diets (BDs) for Groups 1 and 2 were supplemented with the equivalent amounts of trace elements in an inorganic form (Cu sulphate 5 mg·kg-1 DM, Fe sulphate, Zn oxide, Mn oxide 50 mg·kg-1 DM), however sodium selenite or selenized yeast (Sel-Plex) were given at a dose of Se 0.3 mg·kg-1 DM, respectively. Groups 3 and 4 received the same BD´s but with the substantially reduced amount of supplemented nutrients in the organic “proteinated” form (Bioplex Cu 2.5 mg·kg-1 DM, Bioplex Fe, Bioplex Zn, Bioplex Mn 10 mg·kg-1 DM), except for selenium that was given at a dose of Se 0.3 mg·kg-1 DM as sodium selenite or Sel-Plex, respectively. The supplementation of restricted doses of trace elements in the organic forms into the diet did not affect studied haematological, immunological, enzymatic indices. At the age of 21 days, the activity of GSH-Px was significantly higher in the groups supplemented with sodium selenite later no differences due to the administered form of Se were found. This indicates that the GSH-Px activity reached a plateau in all groups of broilers at the 21, 35 and 42 day, except for GSH-Px activity in the groups of birds supplemented with selenized yeast on day 21. In Addition, significant age dependent changes were observed in blood chemistry, but the different treatments did not influence these changes. Base on our results, the doses of organic forms of trace elements supplemented into the diets for poultry can be restricted to 50% (Bioplex Cu) and 20% (Bioplex Fe, Bioplex Zn and Bioplex Mn) without influencing the blood chemistry of broilers.

Effects of chelated trace minerals on growth performance, breast meat yield, and footpad health in commercial meat broilers

SUMMARY Dietary supplementation of trace minerals with a large safety margin is common practice in the poultry industry to prevent trace mineral deficiency. However, oversupplementation of inorganic trace minerals often results in poor bioavailability and low body retention, and can result in more than 90% of the dietary trace minerals being excreted into the environment. In this trial, litter mineral concentrations at the conclusion of the study had very high concentrations of Ca (2.3%), P (1.7%), Cu (150 ppm), Fe (350 ppm), Mn (420 ppm), and Zn (350 ppm). It has been demonstrated that chelated trace minerals are more bioavailable, perhaps because of reduced loss to antagonisms in the intestinal lumen compared with inorganic sources. In 2 commercial broiler trials, performance, meat yield, and footpad health associated with reducing Zn and Mn supplementation while feeding a 50:50 blend of inorganic (sulfates) and chelated forms of Zn, Cu, and Mn were tested. Birds fed the blended treatment exhibited similar or improved growth performance and similar tissue mineral storage compared with those fed the inorganic trace mineral control. In addition, chelated trace minerals improved breast meat yield and footpad health in one trial. In summary, chelated trace minerals are effective alternative trace mineral sources for satisfying the trace mineral needs of rapidly growing broilers and allowing for a reduction in dietary mineral supplementation, thereby potentially reducing the excretion of minerals into the environment.

Manganese Supplementation Reduces the Blood Cholesterol Levels in Ca-Deficient Ovariectomized Rats

Manganese (Mn) is an essential element for normal development and bodily functions in humans. In the present study, we examined whether Mn supplementation can alter the serum lipid parameters and liver function in Ca-deficient ovariectomized (OVX) rats. Sixty female Sprague-Dawley rats (6weeks) were divided into five groups and bred for 12weeks: sham-operated control group (Sham), OVX Ca deficiency group (OLCa) with Ca-deficient diet (0.1% Ca modified AIN-93N diet), OVX Ca deficiency and Mn supplementation group (OLCaMn), OVX with adequate Ca group (OACa; 0.5% Ca AIN-93N diet), and OVX with adequate Ca and Mn supplementation group (OACaMn). A low Ca diet increased the liver weight and serum levels of GOT, GPT, total cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol in OVX rats. Mn supplementation decreased these parameters in Ca-deficient OVX rat. The results of our study suggest Mn supplementation results in reductions of the blood cholesterol levels, which show an increase due to Ca deficiency in OVX rats.

209 Delayed Enteral Feeding Reduces Small Intestinal Nutrient Absorption and Impairs Clinical Outcomes in Critically Ill Patients

BACKGROUND: Since the introduction of long-term total parenteral nutrition (TPN), morbidity due to inadequate replacement or toxicity of micronutrients has been well-described. More recently, recognition of hypermanganesemia and its associated complications has become a significant health concern. Manganese (Mn) is a trace element with affinity for the extrapyramidal system. It can be neurotoxic when in excess. The Mn content of commercially available trace element formulations far exceeds the American Society of Parenteral and Enteral Nutrition (ASPEN) clinical guidelines. Moreover, supplementation itself has been questioned as Mn deficiency in humans is anecdotal. Manganese poisoning presents clinically as Parkinsonian-like symptoms. Accumulation occurs in the basal ganglia as shown by symmetric, increased signal intensity on T1-weighted magnetic resonance images (MRI). AIMS: To prospectively survey the incidence of hypermagnesemia and radiographic evidence of Mn neurotoxicity in our long-term TPN population. METHODS: Sixteen (N=16) patients agreed to participate after informed consent. Each underwent baseline clinical, biochemical and MRI Brain evaluations. Descriptive statistics were attained. RESULTS: Eighty-one percent of patients (N=13/16) had significant Mn deposits in their basal ganglia on T1-weighted images. There was no difference in baseline clinical characteristics (presence of short gut syndrome or liver disease, length of TPN support, daily amount Mn provision, and whole blood Mn level) amongst those with MRI deposits versus those without. Ten (62.5%) had short bowel syndrome. The mean body mass index was 21.56 ± 0.69, with an average of 9.4 years of TPN support. The mean daily Mn supplementation was 7.28 ± 0.97 umol/day (400 ± 53 ug/day), which far exceeded the ASPEN 2002 recommendations of 1.09-1.82 umol/day (60-100 ug/day). The mean whole blood Mn level was 1.38 ± 0.29 times the upper limit of normal. Only two patients with positive MRI (15%) had a clinical diagnosis of Parkinson's disease. However, multiple neuropsychiatric complaints were reported, including depression (66%), lack of concentration (42%), memory disturbances (17%) and gait instability (8%). CONCLUSION: The Mn content of current commercially available trace element concentrates for TPN is likely excessive, as nearly all of our chronic TPN patients were hypermagnesemic and demonstrated significant basal ganglia deposits on MRI evaluation. Further research is necessary to better define the safe standards of Mn supplementation and to incur a paradigm shift in the current manufacturing of parenteral micronutrient formulations.

Effect of amount and source of manganese and/or phytase supplementation on productive and reproductive performance and some physiological traits of dual purpose cross-bred hens in the tropics

1. The effect of different amounts of added manganese (Mn) (0, 10, 20 and 40 mg/kg) in inorganic and organic form and phytase (0 and 300 U) was investigated on productive, reproductive and haematological traits on 480 hens and 60 cocks (Inchas breeds) divided into 12 groups: 10 and 20 Mn × 0 and 300 phytase × 2 Mn sources (8 groups), two negative controls (0 Mn × 2 levels of phytase) and two positive controls (40 Mn × 2 Mn sources). 2. Phytase supplementation increased laying rate by 1·1% and egg weight by 0·4 g. 3. Manganese supplementation at 10 mg/kg over dietary sources improved hatchability, at 20 mg/kg decreased death embryos and abnormality as those of hens supplemented with 40 mg/kg Mn. Inorganic Mn at 10 mg/kg significantly increased egg mass compared to the organic form. Inorganic Mn was more efficient in decreasing abnormal chicks than organic Mn. Phytase supplementation significantly increased hatchability of fertile eggs and decreased the number of abnormal chicks of groups fed on diets unsupplemented with Mn and those supplemented with 10 mg/kg Mn. 4. Mn supplementation at 10 mg/kg over dietary sources significantly improved sperm mass motility and decreased abnormal sperm. Phytase significantly decreased lymphocyte cells and plasma AST. 5. Mn supplementation of the control diet (containing only 16 mg/kg from raw materials) with 20 mg/kg of Mn from either organic or inorganic source is adequate to support egg production traits, egg quality, reproductive traits and economic efficiency of dual purpose cross-bred hens; however, phytase supplementation may reduce the required Mn supplementation to 10 mg/kg.

The influence of inflammation on plasma zinc concentration in apparently healthy, HIV+ Kenyan adults and zinc responses after a multi-micronutrient supplement

Plasma zinc is an important biomarker of zinc status, but the concentration is depressed by inflammation. Apparently healthy adults, who tested positive twice for human immunodeficiency virus (HIV) but who had not reached stage IV or clinical AIDS, were randomly allocated to receive a food supplement (n=17 and 21) or the food plus a micronutrient capsule (MN; n=10 men and n=33 women) containing 15 mg zinc/day. We used the inflammation biomarkers, C-reactive protein (CRP) and alpha1-acid glycoprotein (AGP), to identify subjects with and without inflammation and determine the effect of inflammation on the response of plasma zinc concentrations to the MN and food supplements. There were no differences between men and women either in plasma zinc or in the responses to the supplements and their data were combined. Plasma zinc was lower in those with inflammation than without. Repeated measures analysis of variance (ANOVA) showed that inflammation blocked increases in plasma zinc, and there was an approximate 10% increase in plasma zinc concentration in response to the MN supplement (P=0.023) in those without inflammation. Subgroup analysis showed mean changes in plasma zinc of 0.95 and -0.83 micromol/l (P=0.031) in response to the MN and food treatments, respectively, in those without inflammation at both time points. Inflammation seems to block any increase in plasma zinc after MN supplement and it is important to identify those without inflammation to determine the effectiveness of a zinc supplementation program.

Effect of Supplemental Inorganic Zn and Mn and their Interactions on the Performance of Broiler Chicken, Mineral Bioavailability, and Immune Response

The purpose of this study was to investigate the interaction and main effects of supplemental Zn and Mn levels on growth, tissue mineral uptake, and immune response in broiler chicken. A basal diet of corn-soybean meal was supplemented with Zn at 40, 80, or 160 ppm and Mn at 60, 120, or 240 ppm in a factorial pattern to constitute nine experimental diets. Each diet was offered to nine replicates of six chicks in stainless steel battery brooders. At 35 days of age, body weight gain, feed conversion efficiency, hock joint scores, tibia weight, tibia strength, and percent ash were not influenced by Zn and Mn levels and their interactions. The concentration of Zn (207-238 ppm) and Mn (11.8-16.3 ppm) in tibia increased linearly with progressive raise of mineral inclusion in diets. Mn at 240 ppm level caused higher retention of Zn in tibia, but not vice versa. Manganese either alone or in combination with Zn (Zn160/Mn120 ppm) significantly reduced Cu retention (10.1-7.2 ppm) in tibia. Even in the hepatic tissue, Zn (93.6-98.4 ppm) and Mn (9.3-10.2 ppm) concentration increased linearly with their levels of inclusion in diets. When Zn and Mn levels were maintained at 4:3 ratio (80:60 or 160:120 ppm), the concentration of Zn (100-106 ppm) in liver was higher, while that of Mn was significantly more with low level of Zn (40 ppm) in diet. However, Mn supplementation at 120 ppm level and above significantly decreased Cu accumulation (19.5-17.1 ppm) in liver, but Mn × Zn interaction had no effect on Cu retention. The immune response measured as antibody titers to sheep RBC increased (5.9-7.9 log(2)) significantly with higher Zn (80 ppm) supplementation and cell-mediated immune response to phytohemagglutinin (0.57-0.78) with Mn level at 120 ppm. In summary, Zn (40 ppm) and Mn (60 ppm) as recommended by NRC was sufficient for broiler performance and bone parameters. Mn complimented Zn retention in tibia and antagonized Cu in tibia and liver tissues. Higher levels of Zn (80 ppm) and Mn (120 ppm) than those recommended by NRC were needed for improved immune response in broilers at 35 days of age.

Effect of Cu&lt;sup&gt;2+&lt;/sup&gt;, Mn&lt;sup&gt;2+&lt;/sup&gt; and aromatic compounds on the production of laccase isoforms by &lt;i&gt;Coprinus comatus&lt;/i&gt;

Six different extracellular laccase isoforms were identified in submerged cultures of the commercially important edible mushroom, Coprinus comatus. Although laccase activity (~55IU/L) was readily detectable in unsupplemented control cultures containing 1.6μM Cu2+ after 22-day incubation, mean enzyme levels (~150–185IU/L) were 2.7–3.4-fold higher in cultures supplemented with 0.5–3.0mM Cu2+. Laccase production was also stimulated by Mn supplementation over the range 0.05–0.8mM Mn2+, and the peak value of ~225IU/L recorded after 22 days in cultures containing 0.8mM added Mn2+ was 4.5-fold higher compared with unsupplemented controls. Of 12 aromatic compounds tested for their effect on laccase isozyme production by C. comatus, highest laccase levels ~188IU/L), equivalent to a 4.4-fold increase compared with unsupplemented controls (~43IU/L), were recorded after 22 days in cultures supplemented with 3.0mM caffeic acid. Other aromatic compounds tested all stimulated laccase production, with peak enzyme levels 1.3–3.3-fold higher compared with unsupplemented controls. Extracellular laccase levels in cultures supplemented with optimal concentrations of Mn2+ and caffeic acid together were 38% and 15% lower, respectively, compared with cultures containing the separate supplements. Lac1 was the most abundant laccase isoform produced under all the conditions tested, but marked differences were observed in the production patterns of Lac2–Lac6.

Effect of Cu2+, Mn2+ and aromatic compounds on the production of laccase isoforms by Coprinus comatus

Six different extracellular laccase isoforms were identified in submerged cultures of the commercially important edible mushroom, Coprinus comatus. Although laccase activity (~55IU/L) was readily detectable in unsupplemented control cultures containing 1.6μM Cu2+ after 22-day incubation, mean enzyme levels (~150–185IU/L) were 2.7–3.4-fold higher in cultures supplemented with 0.5–3.0mM Cu2+. Laccase production was also stimulated by Mn supplementation over the range 0.05–0.8mM Mn2+, and the peak value of ~225IU/L recorded after 22 days in cultures containing 0.8mM added Mn2+ was 4.5-fold higher compared with unsupplemented controls. Of 12 aromatic compounds tested for their effect on laccase isozyme production by C. comatus, highest laccase levels ~188IU/L), equivalent to a 4.4-fold increase compared with unsupplemented controls (~43IU/L), were recorded after 22 days in cultures supplemented with 3.0mM caffeic acid. Other aromatic compounds tested all stimulated laccase production, with peak enzyme levels 1.3–3.3-fold higher compared with unsupplemented controls. Extracellular laccase levels in cultures supplemented with optimal concentrations of Mn2+ and caffeic acid together were 38% and 15% lower, respectively, compared with cultures containing the separate supplements. Lac1 was the most abundant laccase isoform produced under all the conditions tested, but marked differences were observed in the production patterns of Lac2–Lac6.

Effect of Complexed Trace Minerals on the Performance of Lactating Dairy Cows on a Commercial Dairy

On a commercial dairy, 306 Holstein cows were blocked by parity and expected calving date and were used in a randomized complete block design to determine the effect of treatment on claw integrity, lactation, and reproduction. Treatments were 1) all supplemental Zn, Mn, Cu, and Co supplied by sulfates, and 2) 360 mg Zn, 200 mg Mn, 125 mg Cu, and 25 mg Co from sulfates replaced by similar amounts of trace minerals supplied by specific amino acid complexes of Zn, Mn, and Cu and by Co-glucoheptonate [complexed trace minerals (CTM); 4-Plex, Zinpro Corp., Eden Prairie, MN]. All cows were fed inorganic trace minerals for 4 mo before initiation of treatments. Cows received treatments from 21 d prepartum through 250 d postpartum. There was no effect of treatment (P > 0.15) on yields of milk, 3.5% FCM or energy-corrected milk. Cows fed sulfates tended (P = 0.105) to produce more milk fat and milk with a greater fat content (P = 0.045). Cows fed CTM tended to have lower SCC in milk (P = 0.08) and linear SCC score (P = 0.06) than cows fed sulfates. Survival curve analysis indicated feeding CTM tended to generate more pregnancies and at a faster rate (P = 0.08) than cows fed sulfates. Feeding sulfates decreased (P < 0.01) the severity of hemorrhages, whereas feeding CTM decreased (P < 0.01) the incidence of heel erosion. In conclusion, replacing a portion of the inorganic sulfate sources of Zn, Cu, Mn, and Co with those trace minerals supplied by CTM improved some aspects of milk quality and reproductive performance.

Manganese in Parenteral Nutrition: Who, When, and Why Should We Supplement?

Micronutrient requirements are not fully understood. Parenteral nutrition (PN) usually contains the trace element (TE) manganese (Mn) from fixed-concentration TE supplements. Multiple TE formulations may not be optimal in pediatric and home PN. Moreover, most PN products contain Mn as a ubiquitous contaminant. Excessive Mn can lead to Parkinson-like symptoms resulting from hypermanganesemia. A survey of 40 Australasian hospitals that contributed data on 108 patients to the annual home PN register and a systematic review of the literature were conducted to establish the scope of the potential problem of Mn toxicity in PN patients. Exposure to Mn doses 5-6 times current daily requirements, together with the TE contamination that is reported in PN products, can lead to neurotoxicity. Whole-blood levels are more accurate for monitoring and correlate well with signal intensity of magnetic resonance imaging. Current TE formulations restrict prescribing options. The regulatory mechanisms of Mn homeostasis are bypassed via the parenteral route so elimination via the hepatobiliary system is impaired, resulting in tissue or brain accumulation. Published dosage recommendations may be excessive and official guidelines require revision. Variability in clinical practices necessitates that individual TE additives are more widely available and multiple TE products reformulated. More frequent monitoring for any brain accumulation is recommended. The scarcity of PN-associated Mn deficiency, plus the growing evidence for Mn toxicity, leads to the conclusion that it is unnecessary for Mn to be prescribed routinely for pediatric or long-term PN patients.

Salmonella–Macrophage Interactions upon Manganese Supplementation

Various studies indicate the role of manganese (Mn) in the virulence of pathogens. Salmonella is an intracellular pathogen which is able to multiply within the macrophages. The present study was therefore, designed to assess the effect of Mn supplementation on Salmonella-macrophage interactions particularly in reference to Salmonella virulence and macrophage functions. A 50-fold decrease in the lethal dose 50 (LD(50)) of Salmonella typhimurium was observed when mice were infected with Salmonella grown in the presence of Mn as compared to the LD(50) in the absence of Mn indicating an increase in the virulence of the organism. A significant increase was observed in the levels of superoxide dismutase (SOD) of S. typhimurium grown in presence of manganese. Upon Mn supplementation, macrophage functions were also found to be altered. Decreased phagocytic activity of macrophages interacted with Salmonella was observed in presence of Mn as compared to the activity in the absence of Mn. A significant increase was observed in the extent of lipid peroxidation along with significant decreases in the activities of SOD and catalase as well as nitrite levels of macrophages interacted with S. typhimurium upon supplementation with Mn. These observations indicate that Mn supplementation might have increased the expression of Mn transporters in Salmonella resulting in increased levels of its superoxide dismutase. The altered Salmonella function in turn might have been responsible for inhibiting phagocytosis and impairing the balance between the oxidant and antioxidant profile of macrophages, thus protecting itself by exhibiting exalted virulence.

Effect of Pleurotus ostreatus fermentation on cocoa pod husk composition: Influence of fermentation period and Mn2+ supplementation on the fermentation process.

Cocoa pod husk (CPH) is a major agro-industrial residue in Ghana with a potential value as a low-cost unconventional feedstuff for livestock. However, its effective use is limited by poor nutrient composition, mainly due to its high lignocellulose or fibre and also low protein levels. White–rot fungi such as Pleurotus species are bio-catalytic systems for bioconversion processes such as the bioconversion of lignocellulose materials into value-added products including nutritious animal feed. Presence of metals such as manganese (II) ions is reported to enhance fungal enzyme activity in the bioconversion of industrial lignocellulosic residues. The current study investigated the viability of using and optimising a fermentation process involving edible oyster mushroom (Pleurotus ostreatus) as biocatalyst to improve the nutritional status of CPH. Fermentation period and level of manganese (Mn2+) ion supplementation of CPH were the two major factors of the fermentation process evaluated and optimised in this study. Mn supplementation was critical in producing a positive bioconversion effect on CPH by P. ostreatus. Five (5) weeks of P. ostreatus solid-state fermentation of CPH amended with MnCl2 at 0.075% (w/w) concentration, was observed as an economic and optimum treatment to produce positive and significant (P < 0.05) changes in CPH composition, i.e. 36% increment in crude protein and total soluble carbohydrates; 17% reduction in crude fibre and lignin as well as 88% reduction in total tannins.