Addition Of Micronutrients Research Articles

The Internal Market, Incomplete: EU, Dutch and Belgian Legislation on Maximum Food Fortification with Micronutrients

The article shows that food fortification legislation at the EU level leaves the achievement of the internal market incomplete. Regulation (EC) No 1925/2006 on the addition of vitamins, minerals and certain other substances to foods regulates the addition of micronutrients to food. A regulatory check of two markets in the European Union (EU) shows that EU countries at national level take diverging approaches to food fortification. In the Netherlands, food fortification with vitamin A (in the form of retinoid), selenium, copper and zinc is prohibited if it concerns food fortification in the strict sense. This regime is subject to an exemption authorisation scheme. The main reason why food fortification with some substances is not allowed in the Netherlands is because the range between the Recommended Daily Average (RDA) and the maximum Tolerable Upper Intake Level (UL) is too small. A safe level of intake would then not be much higher than the RDA. In this article, the different ranges between the RDA’s and the UL in the Netherlands, Belgium and the EU have been compared. Following the results of this report, these ranges do not seem to differ substantially and therefore, a priori do not seem to be a convincing scientific argument for divergent legislation on whether or not to prohibit food fortification with specific micronutrients. The results are discussed in light of EU regulation of on the addition of vitamins and minerals and the free movement of goods.

Global pattern and controls of biological nitrogen fixation under nutrient enrichment: A meta-analysis.

Biological nitrogen (N) fixation (BNF), an important source of N in terrestrial ecosystems, plays a critical role in terrestrial nutrient cycling and net primary productivity. Currently, large uncertainty exists regarding how nutrient availability regulates terrestrial BNF and the drivers responsible for this process. We conducted a global meta-analysis of terrestrial BNF in response to N, phosphorus (P), and micronutrient (Micro) addition across different biomes (i.e, tropical/subtropical forest, savanna, temperate forest, grassland, boreal forest, and tundra) and explored whether the BNF responses were affected by fertilization regimes (nutrient-addition rates, duration, and total load) and environmental factors (mean annual temperature [MAT], mean annual precipitation [MAP], and N deposition). The results showed that N addition inhibited terrestrial BNF (by 19.0% (95% confidence interval [CI]: 17.7%-20.3%); hereafter), Micro addition stimulated terrestrial BNF (30.4% [25.7%-35.3%]), and P addition had an inconsistent effect on terrestrial BNF, i.e., inhibiting free-living N fixation (7.5% [4.4%-10.6%]) and stimulating symbiotic N fixation (85.5% [25.8%-158.7%]). Furthermore, the response ratios (i.e., effect sizes) of BNF to nutrient addition were smaller in low-latitude (<30°) biomes (8.5%-36.9%) than in mid-/high-latitude (≥30°) biomes (32.9%-61.3%), and the sensitivity (defined as the absolute value of response ratios) of BNF to nutrients in mid-/high-latitude biomes decreased with decreasing latitude (p≤0.009; linear/logarithmic regression models). Fertilization regimes did not affect this phenomenon (p>0.05), but environmental factors did affect it (p<0.001) because MAT, MAP, and N deposition accounted for 5%-14%, 10%-32%, and 7%-18% of the variance in the BNF response ratios in cold (MAT<15°C), low-rainfall (MAP<2,500mm), and low-N-deposition (<7kgha-1 year-1 ) biomes, respectively. Overall, our meta-analysis depicts a global pattern of nutrient impacts on terrestrial BNF and indicates that certain types of global change (i.e., warming, elevated precipitation and N deposition) may reduce the sensitivity of BNF in response to nutrient enrichment in mid-/high-latitude biomes.

Storage of Soybean Seeds and Addition of Insecticide and Micronutrients

The objective of this work was to evaluate the effects on the physiological attributes of soybean seeds submitted to the seed treatment with addition of insecticide, polymers and micronutrients throughout the storage. The experimental design was completely randomized in a factorial scheme, with four seed treatments per two seasons of storage of the seeds. The analysis of variance revealed a significant interaction among seed treatments and storage times for both cultivars at 5% of probability, referring to the characteristics of shoot length (SL), primary root length (RL), shoot dry mass (SDM) and dry mass of the primary root (RDM) for the cultivar Fundacep 37 RR. Addition of seed treatments influences the physiological performance of seedlings originated from soybean seeds stored for 240 days. The shoot and primary root lenghts, and shoot dry mass express the isoenzyme esterase through the aerial part and primary root of the seedling, the malate dehydrogenase is expressed in the primary root while in the peroxidase it is evident in the shoot of the seedlings.

The Effect Of Cellulase Content On Phytoestrogens Formation (Genistein) Materials On Fermented Soybean Waste Aspergillus niger

The activity of the cellulase enzyme and the content of phytoestrogen (genistein) forming is determined during the fermentation of soybean waste with Aspergullus niger. The analysis is performed at fermentation incubation time of 0, 48, 96, 144 and 192 hours and treatment with addition of micro nutrient (V2) and without micro nutrient (V1). Data analysis on cellulase enzyme activity on phytoestrogen forming material is performed using T test. The average of cellulase content of fermented soybean waste increases from 0.032-0.139 IU / ml (V1) and 0.061-0.158 IU / ml (V2) after 48 hours into 0.238 IU / ml (V1) and 0.245 IU / ml (V2) after 192 hours The average of genestein levels in the fermented soybean waste increases as well from 0.101 - 0.573 mg / g (V1) and 0.114 - 0.587 mg / g (V2) after 48 hours and increase into 0.722 mg / g (V1) and 0.699 mg / g (V2) after 192 hours. Statistical analysis indicates that the treatment of V1 and V2 has an effect on the increase of cellulase enzyme content and genistein level (P 0.05). The correlation between enzyme activity of cellulase and genistein on soybean waste fermented with Aspergillus niger is significant (R2 = 0,949). The relationship between the enzyme performance and its formation material is running synergistic, cellulase enzyme activity and genistein level experience significant increase during the fermentation process.

Investigation on the feasibility of Chlorella vulgaris cultivation in a mixture of pulp and aquaculture effluents: Treatment of wastewater and lipid extraction

In this study, feasibility of Chlorella vulgaris cultivation in pulp wastewater (PWW) diluted with lake water (LW) and aquaculture wastewater (AWW) was investigated. The best ratios of PWW and AWW (PAWW) viz., 80% PWW:20% AWW and 60% PWW:40% AWW were selected as microalgal culture medium. Algal growth was investigated with and without addition of macro and micronutrients to the cultivation medium. The highest dry algal weight was observed as 1.31 g/L in 60% PWW:40% AWW without adding micronutrients. Nutrients and organic compounds removal efficiencies by microalga were studied in PAWW. Protein, carbohydrate and lipid percentage of harvested microalga from wastewater and Bold's Basal Medium (BBM) solution were analyzed. Fatty acids analysis revealed that C16 and C18 are the major fatty acids in C. vulgaris cultivated in BBM and PAWW. The results of this study revealed that C. vulgaris is a potential candidate for PAWW treatment and lipid and carbohydrate accumulation.

Addition of micronutrients to npk formulation and initial development of maize plants

Addition of micronutrients to npk formulation and initial development of maize plants

Effect of macro- and micro-nutrients addition during anaerobic mono-digestion of grass silage in leach-bed reactors

ABSTRACT The effect of macro- (NH4Cl) (set I) and micro-nutrients (Fe, Ni, Co and Mo) (set II) addition on chemical oxygen demand (COD) solubilisation during anaerobic mono-digestion of grass silage was investigated in two sets of leach bed reactor experiments at 35°C. Results showed that addition of NH4Cl and micro-nutrients improved COD solubilisation by 18% (0.56 g SCOD g−1 volatile solids) and 7% (0.45 g SCOD g−1 VS), respectively than control. About 20–50% of the added micro-nutrients were bioavailable in the produced leachates, while the rest (50–80%) were adsorbed onto the grass silage. Results of biological methane potential assays showed that, specific methane yields of grass silage were improved by 17% (0.36 ± 0.02 m3 CH4 kg−1 VSadded) when NH4Cl was supplemented while Fe, Ni, Co and Mo addition improved methane yields by 15% (0.33 ± 0.005 m3 CH4 kg−1 VSadded) when compared to control.

Evaluación de factores que afectan la bioacidulación de roca fosfórica bajo condiciones in vitro

El fósforo (P) es un nutriente esencial para el desarrollo de las plantas, desafortunadamente, su disponibilidad en muchos suelos es baja. Consecuentemente, los agricultores aplican altas cantidades de fertilizantes fosfóricos solubles, pero esto es ineficiente y costoso. El uso directo de roca fosfórica (RP) es muy atractivo por su bajo costo; sin embargo, es poco soluble y de baja eficiencia agronómica. Para superar esta limitación, hay un creciente interés en el uso de microorganismos del suelo capaces de disolverla y mejorar su valor como fertilizante. El objetivo de este trabajo fue evaluar el efecto que tienen algunos factores sobre la capacidad del hongo Mortierella sp. para disolver RP bajo condiciones in vitro. Estos factores son: (i) tiempo de incubación, (ii) tipo de RP, (iii) concentración inicial de P soluble y (iv) adición de vitaminas y micronutrientes. Despues del periodo de incubación se midió P en solución y pH. Los resultados indican que producto de la biodisolución de RP la más alta concentración de P en solución se alcanzó al día 5. Por otro lado, la biodisolución de RP fue reducida por la adición de vitaminas y micronutrientes y por el incremento en la concentración inicial de P soluble en el medio. Aunque la disolución microbiana fue más efectiva con la RP de Carolina del Norte, las RP del Huila y Santander presentaron un buen nivel de disolución en un periodo de tiempo corto. La bioacidulación mejorara la efectividad agronómica de la RP para su uso directo o a través de un proceso biotecnológico previo.

Contrasting Photo-physiological Responses of the Haptophyte &lt;em&gt;Phaeocystis Antarctica&lt;/em&gt; and the Diatom &lt;em&gt;Pseudonitzschia&lt;/em&gt; sp. in the Ross Sea (Antarctica)

The Antarctic is a unique environment in which substantial variations in irradiance occur over a number of time scales, and as a result phytoplankton need to acclimate and adapt to these changes. We conducted field and laboratory manipulations in the Ross Sea, Antarctica to examine photophysiological differences between Phaeocystis antarctica and Pseudonitzschia sp. a diatom that commonly occurrs in the Ross Sea, since these are the two functional groups that dominate abundance and productivity. Both exhibited reduced quantum yields due to high irradiances. P. antarctica , a haptophyte, displays a distinct photophysiological response to irradiance when compared to diatoms. P. antarctica showed a rapid recovery from high light exposure, as indicated by the rapid return to initial, high quantum yields, in contrast to diatoms, which responded more slowly. Absorption cross sections were high in both forms, but those in P. antarctica were significantly higher. Both organisms recovered within 24 h to initial quantum yields, suggesting that high irradiance exposure does not have a permanent effect on these organisms. Among all micronutrient additions (iron, cobalt, zinc and vitamin B 12 ), only iron additions resulted in rapid impacts on quantum yields. Iron limitation also can result in reduced photosynthetic efficiency. Understanding these photophysiologial responses and the impact of oceanographic conditions provides constraints on modeling efforts of photosynthesis and primary productivity in the Antarctic.

Further investigations of aquaponics using brackish water resources of the Negev desert

Outdoor, floating raft aquaponic systems using the brackish waters of the Negev Desert in Israel and a fresh water control are described. 7 m2 of vegetables and herbs were grown in each recirculating system with Tilapia sp. fish. Plant growth was excellent for species such as celery, Swiss chard, spring onions and watercress, and fish health and growth were good. Growth rates for fish were, however, low, with an upper limit of 1.1 g per day and would have increased with ad libitum feeding. Water quality was well controlled, and iron chelate was added to correct chlorosis problems. Leafy growth was very good, but fruiting could be improved with the addition of potassium (K) and other micronutrients.

Challenges of Food Security – Need for Interdisciplinary Collaboration

A peep into the ways global systems have impacted food security and the scientific processes to enhance food productivity is being outlined .Challenges such as food safety, global environmental changes and malnutrition need a multidisciplinary approach to tackle the issues associated with them. Multidisciplinary research in diverse areas related to crop production, public health, biological, physical and mathematical sciences, predictive modeling, statistical approaches etc. is the need of the hour. The coming together of all stake holders involved in science, technology and social sciences is required to implement progressive approaches to maximize production for feeding the ever increasing population and involves studies related to storage, manufacture, retail, food supply and value chain, reducing waste by preventing post harvest losses, recycling, making food safe by eliminating food related illness due to biological and chemical hazards, adopt best measures of preservation of quality, micronutrient addition to food for enhancing nutrition etc. All of the above needs to be addressed for sustaining global food security.

THE EFFECT OF F/M RATIO TO THE ANAEROBIC DECOMPOSITION OF BIOGAS PRODUCTION FROM FISH OFFAL WASTE

Biogas is a gas produced from the anaerobic decomposition of organic compounds. In the production of biogas from anaerobic digestion, value of F/M ratio shows a ratio between the mass of food available in the waste substrate with a mass of microorganisms that act as decomposers. F/M ratio is too small causing microbes could not metabolize perfectly and vice versa on the value of the ratio F / M overload resulting metabolic imbalance. The purpose of this study was to assess the effect of F/M ratio to optimal production of biogas from fish offal waste. The process of anaerobic digestion is conducted in the biodigester with four-liter volume and batch system operated at ambient temperature for 38 days. As a raw material, fish offal and microbial sludge obtained from the curing of fish and river mud discharges in the region of Bandarharjo, Semarang, Central Java. F/M ratio is set at 0.2, 0.4, and 0.6 are derived from sewage sludge VSS weight ratio of fish offal with sludge containing microbes. The addition of micronutrients supplied with a concentration of 0.4 mg/liter. Yield maximum methane gas obtained was 164,7 l/kg CODMn when the ratio F/M was 0.2. Based on the results of the study, found that the ratio F/M affect the amount of biogas produced. Meanwhile, the retention time (HRT) is only influenced by the ratio F/M.

Effects of endogenous and exogenous micronutrients in rapeseed oils on the antioxidant status and lipid profile in high-fat fed rats.

BackgroundMicronutrients in oil reduce one or more risk factors of cardiovascular diseases, while the contents of micronutrients in oil are relatively poor, which is insufficient to reverse the metabolic disorders at different stages of progress. The aim of this study was to investigate the effects of endogenous micronutrients in optimized cold-pressed rapeseed oil and restoratively added or fortified micronutrients in traditional refined rapeseed oil (restoring micronutrients to be nearly equal to or significantly higher than levels in crude rapeseed oil) on the antioxidant status and lipid profile in high-fat fed rats.MethodsMale Wistar rats were fed high-fat diets containing different rapeseed oils for 4 weeks, including the standard refined rapeseed oil(SRO), optimized cold-pressed rapeseed oil(CRO) and the traditional refined rapeseed oil with restorative addition or fortification of micronutrients (LF, HF-SRO).ResultsCRO exhibited significant increases in contents of tocopherols (+13%), phytosterols (+34%), polyphenols (+92%) and phospholipids (+725%) compared with SRO, as well as the total antioxidant capacities (+82-125%) (p < 0.05). While the HF-SRO revealed improved antioxidant properties in vitro than the CRO, which was comparable to LF-SRO. Significant improved plasma antioxidant capacities and lipid peroxidation evaluated by T-AOC, GSH, tocopherols and MDA were found in rats fed HF-SRO when compared with CRO and LF-SRO (p < 0.05). Furthermore, HF-SRO also decreased the plasma and hepatic TC levels compared to CRO and LF-SRO, accompanying higher fecal cholesterol excretion (p < 0.05).ConclusionThe standard refined rapeseed oil with fortification, not restorative addition of micronutrients was comparable to the optimized cold-pressed rapeseed oil in improving the antioxidant status and lipid profile of high-fat fed rats.

Aya Hirata Kimura: Hidden hunger: gender and the politics of smarter foods

In Hidden Hunger, Aya Kimura, a colleague of mine at the University of Hawai’i, explores ‘‘how and why fortification and biofortification became the preferred ‘solutions’ to the Third World food problem.’’ Fortification refers to the addition of micronutrients to food products during the manufacturing process. Biofortification is the biological alteration of crops so that the plants themselves contain more micronutrients. There are many exaggerated health claims about fortified processed foods. These claims are often associated with inflated retail prices. This pattern in high-income countries has been well documented by food scholars such as Marion Nestle and Michael Pollan. Through her broad overview and her case studies in Indonesia, Kimura shows how the pattern is penetrating more and more deeply into the food systems of low-income countries. The focus on fortification emphasizes dietary deficiencies while ignoring the roots of widespread, sustained malnutrition. The approach ‘‘effectively depoliticizes the food problem by recasting it as a technical matter.’’ Kimura uses fortification and related issues as her point of entry into exploring the deep culture and politics of modern malnutrition. Kimura shows that the ways people define a problem are largely determined by the remedies they wish to deliver. Until a few decades ago, it was believed that the only thing needed to prevent malnutrition was a diverse supply of good quality food. Now the malnutrition problem is being defined by corporations that have highly specialized products to sell, and their products are being promoted almost as if they were medicines. This study makes a major contribution to the emerging category of feminist food studies. Many others have noted the distinct gender roles, but it is only recently that studies of food systems have been done with a distinctively feminist lens. Despite the dominant role women play in food systems, from primary production in the fields, to processing and marketing, all the way through to final preparation and consumption, their decision-making powers fall far short of what would be expected, given the burdens that they carry. Fortification schemes add to women’s burdens and detract from their power. Suddenly people need chemicals with unrecognizable names, delivered through programs and foods designed by specialists and experts. Where people used to get almost everything they needed from their gardens, they are now told they must get things in boxes and bottles. The advertisements tell them how important it is to provide those boxes and bottles; it is the responsible thing to do. This adds to the pressure to get into paid employment, even if it is for meager wages. In the chapter on baby food, Kimura speaks about the fatty acid DHA (docosahexaenoic acid) added to biscuits and other foods ‘‘to help brain development’’. In an article published in the online International Breastfeeding Journal (Kent 2014). I show that the claims regarding intellectual development from such additives are highly questionable. My analysis focuses on the failure of the United States Food and Drug Administration to ensure the validity of such health claims. Regulation of fortification and related practices in highincome countries is weak, and in low-income countries it is almost completely absent. What can be done about the exaggerated health claims that many food manufacturers G. Kent (&) Department of Political Science, University of Hawai’i, Honolulu, HI 96822, USA e-mail: kent@hawaii.edu

Acidez do solo afetando concentração de micronutrientes, atividade da enzima nitrato redutase e produtividade em plantas de arroz de terras altas

The lowest grain yield of rice under no-tillage system (NTS) in relation to the conventional system may be due to the predominance nitrate in the soil and the low nitrate reductase activity. Another reason may be caused by micronutrient deficiency because of superficially soil acidity corrections. Therefore, the objective of this study was to evaluate the changes caused by soil pH in the N forms in the soil, micronutrients concentration in rice plants, nitrate reductase activity, yield of rice and its components. The experiment was performed in a greenhouse conditions. The experimental design was a completely randomized in a factorial three (levels of soil acidity) x five (micronutrients sources) with four replications. The addition of micronutrients does not affect levels of nitrate and ammonium in the soil; soil acidity significantly affects levels of nitrate and ammonium in the soil, concentration of micronutrients in rice plants and crop yield and its components; medium soil acidity (pH 5.5) result in medium to high levels of Cu and Fe, medium level of Zn and Mn, high nitrate reductase activity, resulting in higher dry matter, tillers, panicles, spikelets, weight of 100 grains and hence grain yield.

Multiple nutrients and herbivores interact to govern diversity, productivity, composition, and infection in a successional grassland

In spite of increasing awareness that interactions between herbivory and the supply rates of multiple nutrients control biodiversity, ecosystem functions and ecosystem services in ecological communities, few experimental studies have concurrently examined the independent and joint effects of multiple nutrients and mammalian consumers on these responses in natural systems. Here we quantify the independent and interactive effects of multiple concurrent changes to resources and consumers in an invaded annual grassland community in California. In a two‐year study using thirty‐seven 400‐m2 plots, we examine interactions among four nutrient treatments (N, P, K and micronutrients) and a keystone herbivore (pocket gopher Thomomys bottae) on four plant community outcomes: 1) plant diversity, 2) functional group composition, 3) net biomass production, an important ecosystem function, and 4) infection risk by a group of viral pathogens shared by crop and non‐crop grasses (barley and cereal yellow dwarf viruses), an important regulating ecosystem service. We found that grassland biodiversity and infection risk were controlled by nutrient identity and supply ratio whereas nutrients interacted strongly with consumers to control grassland composition and net primary productivity. The most important insights arising from this multi‐factor experiment are that net biomass production increased with phosphorus or nitrogen supply; however, when gophers were present, nitrogen caused no net effect on biomass production. In addition, infection risk was driven by phosphorus, nitrogen and micronutrient supply. Infection in a sentinel host increased strongly with the addition of micronutrients or phosphorus; however, infection declined with increasing N/P supply ratio, indicating stoichiometric control of infection risk. Finally, in spite of manipulating multiple factors, plant species richness declined with nitrogen, alone. The importance of higher‐order interactions demonstrates that a multi‐factor approach is critical for effective predictions in a world in which anthropogenic activities are simultaneously changing herbivore abundance and the relative supply of many nutrients.

Production of ethanol and arabitol by Debaryomyces nepalensis: influence of process parameters

Debaryomyces nepalensis, osmotolerant yeast isolated from rotten apple, is known to utilize both hexoses and pentoses and produce industrially important metabolites like ethanol, xylitol and arabitol. In the present study, the effect of different growth substrates, trace elements, nitrogen concentration and initial pH on growth and formation of ethanol and arabitol were examined. Optimum conditions for maximizing the product yields were established: glucose as carbon source, an initial pH of 6.0, 6 g/L of ammonium sulphate and addition of micronutrients. Under these best suited conditions, a concentration of 11g/L of arabitol and 19 g/L of ethanol was obtained in shake flask fermentations. The fermentation was scaled up to 2.5 L bioreactor and the influence of aeration, agitation and initial substrate concentration was also determined. Under optimal conditions (150 g/L glucose, 400 rpm and 0.5 vvm) ethanol concentration reached 52 g/L, which corresponds to a yield of 0.34 g/g and volumetric productivity of 0.28 g/L/h, whereas arabitol production reached a maximum of 14 g/L with a yield and volumetric productivity of 0.1 g/g and 0.07 g/L/h respectively.

High-rate iron-rich activated sludge as stabilizing agent for the anaerobic digestion of kitchen waste

Anaerobic digestion is a key technology in the bio-based economy and can be applied to convert a wide range of organic substrates into CH4 and CO2. Kitchen waste is a valuable substrate for anaerobic digestion, since it is an abundant source of organic matter. Yet, digestion of single kitchen waste often results in process failure. High-rate activated sludge or A-sludge is produced during the highly loaded first stage of the two-phase ‘Adsorptions-Belebungsverfahren’ or A/B activated sludge system for municipal wastewater treatment. In this specific case, the A-sludge was amended with FeSO4 to enhance phosphorous removal and coagulation during the water treatment step. This study therefore evaluated whether this Fe-rich A-sludge could be used to obtain stable methanation and higher methane production values during co-digestion with kitchen waste. It was revealed that Fe-rich A-sludge can be a suitable co-substrate for kitchen waste; i.e. methane production rate values of 1.15 ± 0.22 and 1.12 ± 0.28 L L−1 d−1 were obtained during mesophilic and thermophilic co-digestion respectively of a feed-mixture consisting of 15% KW and 85% A-sludge. The thermophilic process led to higher residual VFA concentrations, up to 2070 mg COD L−1, and can therefore be considered less stable. Addition of micro- and macronutrients provided a more stable digestion of single kitchen waste, i.e. a methane production of 0.45 L L−1 d−1 was obtained in the micronutrient treatment compared to 0.30 L L−1 d−1 in the control treatment on day 61. Yet, methane production during single kitchen waste digestion still decreased toward the end of the experiment, despite the addition of micronutrients. Methane production rates were clearly influenced by the total numbers of archaea in the different reactors. This study showed that Fe-rich A-sludge and kitchen waste are suitable for co-digestion.

The response of microbial biomass and hydrolytic enzymes to a decade of nitrogen, phosphorus, and potassium addition in a lowland tropical rain forest

Nutrient availability is widely considered to constrain primary productivity in lowland tropical forests, yet there is little comparable information for the soil microbial biomass. We assessed microbial nutrient limitation by quantifying soil microbial biomass and hydrolytic enzyme activities in a long-term nutrient addition experiment in lowland tropical rain forest in central Panama. Multiple measurements were made over an annual cycle in plots that had received a decade of nitrogen, phosphorus, potassium, and micronutrient addition. Phosphorus addition increased soil microbial carbon (13 %), nitrogen (21 %), and phosphorus (49 %), decreased phosphatase activity by ~65 % and N-acetyl β-glucosaminidase activity by 24 %, but did not affect β-glucosidase activity. In contrast, addition of nitrogen, potassium, or micronutrients did not significantly affect microbial biomass or the activity of any enzyme. Microbial nutrients and hydrolytic enzyme activities all declined markedly in the dry season, with the change in microbial biomass equivalent to or greater than the annual nutrient flux in fine litter fall. Although multiple nutrients limit tree productivity at this site, we conclude that phosphorus limits microbial biomass in this strongly-weathered lowland tropical forest soil. This finding indicates that efforts to include enzymes in biogeochemical models must account for the disproportionate microbial investment in phosphorus acquisition in strongly-weathered soils.

Efficacy of micronutrient supplement intake in increasing hemoglobin in pregnancy: dose‐effect comparisons with multiple micronutrient in the MINIMat trial in rural Bangladesh

It is unclear how large amount of supplemental iron is required to reach maximum hemoglobin concentration in pregnancy and whether addition of multiple micronutrients modify supplement efficacy In the MINIMat prenatal nutrition trial in Bangladesh (ISRCTN16581394) 4436 pregnant women were randomised into 3 types of supplement; either 30 mg Fe and 400 μg folic acid (FE30), or 60 mg Fe and 400 μg folic acid (FE60), or a multiple micronutrient supplement (MMS) containing a daily allowance of 15 micronutrients including 30 mg Fe and folic acid starting at around 14 wk. Adherence was monitored by use of a drug container equipped with an electronic device (eDEM; Aprex). Number of capsules taken between wk14 and wk30 were converted to amount of iron before dose‐response on hemoglobin concentrations at wk30 of gestation were evaluated using adjusted multivariate regression analyses. All 3 types of supplement produced a significant dose effect up to a similar intake of iron (about 2400 mg) after which no further significant effect was observed. In the intake range below 2400mg and evaluated per mg iron ingested; efficacy of Fe60 was higher then Fe30 and higher than MMS. There was no such difference between Fe30 and MMS. The results showed that a lower total amount of iron than commonly recommended is required for maximum hemoglobin response and addition of multiple micronutrients did not modify efficacy. Main source of funds came from icddr,b Bangladesh, UNICEF, and Sida Sweden