Effect Of Amino Acid Supplementation Research Articles

Increased Dietary Trp, Thr, and Met Supplementation Improves Performance, Health, and Protein Metabolism of Weaned Piglets under Mixed Management and Poor Housing Conditions.

A sanitary challenge was carried out to induce suboptimal herd health while investigating the effect of amino acids supplementation on piglet responses. Weaned piglets of high sanitary status (6.33 ± 0.91 kg of BW) were distributed in a 2 × 2 factorial arrangement into two similar facilities with contrasting sanitary conditions and two different diets. Our results suggest that increased Trp, Thr, and Met dietary supplementation could support the immune systems of piglets under a sanitary challenge. In this manner, AA+ supplementation improved the performance and metabolism of piglets under mixed management and poor sanitary conditions. No major temporal microbiome changes were associated with differences in performance regardless of sanitary conditions or diets. Since piglets often become mixed in multiple-site production systems and facility hygiene is also often neglected, this study suggests that increased Trp, Thr, and Met (AA+) dietary supplementation could contribute to mitigating the side effects of these harmful risk factors in modern pig farms.

Effects of Amino Acid Supplementation to a Low-Protein Diet on the Growth Performance and Protein Metabolism-related Factors in Broiler Chicks.

A low-protein (LP) diet may alleviate the environmental impact of chicken meat production by reducing nitrogen excretion and ammonia emissions. Thus, this study investigated the effect of a 15% reduced protein diet with or without amino acid (AA) supplementation on the growth performance of broiler chicks from 10 to 35 days of age and the underlying mechanism for loss of skeletal muscle mass. Thirty-six male broiler chicks were allocated to three experimental groups based on body weight: control, LP, and essential AA-supplemented LP (LP+AA). The body weight gain, feed conversion ratio, and weight of breast muscles and legs significantly decreased only in the LP group at the end of the feeding period. Plasma uric acid levels were significantly lower in the LP+AA group than those of the other groups. In the LP group, mRNA levels of microtubule-associated protein 1 light chain 3 isoform B were significantly higher in the pectoralis major, whereas those of atrogin-1, muscle RING-finger protein-1, and myoblast determination protein 1 were significantly higher in the biceps femoris compared to those in the control group. There were no significant differences in insulin-like growth factor 1 mRNA levels in the liver or skeletal muscle between groups. These findings suggested that supplementation with essential AAs ameliorated the impaired effects of an LP diet on growth performance in broiler chicks, and that the transcriptional changes in proteolytic genes in skeletal muscles might be related to the impaired effects of the LP diet.

Effect of Amino Acid Supplementation on Iron Regulation after Endurance Exercise

The purpose of this study was to determine the effects of pre-exercise amino acid (AA) supplementation on post-exercise iron regulation. Ten healthy males participated under two different sets of conditions in a randomized, double-blind, crossover design with a washout period of at least 21 days. Participants received either an AA supplement or placebo (PLA) for five consecutive days (4 g/dose, 3 doses/day). On the sixth day, participants ran on a treadmill for 60 min at 70% of maximal oxygen consumption (V˙O2max). Venous blood samples were collected before (baseline), immediately after, and 1 and 3 h after exercise. The serum hepcidin levels increased significantly 3 h post-exercise in both trials when compared to the baseline (p < 0.001), but the levels were not different between trials. The plasma interleukin-6 (IL-6) level significantly increased immediately after exercise compared to the baseline (p < 0.001) and was significantly higher in the AA trial than in the PLA trial (p = 0.014). Moreover, the exercise-induced increase in serum glycerol level was significantly higher in the AA trial (21.20 ± 3.98 mg/L) than in the PLA trial (17.28 ± 4.47 mg/L, p = 0.017). No significant differences were observed between the AA and PLA trials for serum iron, ferritin, and total ketone body levels (p > 0.05). In conclusion, five days of AA supplementation augmented exercise-induced increases in IL-6 and glycerol in healthy males. However, it did not affect post-exercise iron status or regulation.

Sensitivity of broiler performance, organ weights and plasma constituents to amino acid supplementation and reused litter exposure using ideal protein-formulated rations

Effects of amino acid supplementation to ideal protein (IP) formulated rations were investigated on growth performance, plasma metabolites and organ weights of broilers placed on 100% recycled (reused) litter. Day-old Ross308 male broilers were raised on either clean or reused litter and fed for three weeks on one of five isoenergetic diets, where an IP-based control diet (C) was compared with diets containing threonine (T) or arginine (A) at 25% above requirements, or with 1% supplemented glutamine (G), or with each amino acid added (TAG). Litter and diet treatments did not strongly interact on outcomes. Reused litter placement resulted in greater weight gain, smaller feed conversion ratio and heavier bursal weights (P < 0.05) compared to clean litter placement. Relative to C and T birds, TAG birds reduced weight gain and feed intake (P < 0.05). Plasma uric acid levels in G birds were greater than in C, T and A birds (P < 0.001). Collectively, since the outcomes of placement on reused litter increased performance and the control diet was IP formulated, the absence of increased growth performance in response to amino acid supplementation would be consistent with amino acids tested being excess to requirements.

Effect Of Amino Acid Supplementation On Iron Metabolism Following Endurance Exercise

Effect Of Amino Acid Supplementation On Iron Metabolism Following Endurance Exercise

Effects of Amino Acids Supplementation on Lipid and Glucose Metabolism in HepG2 Cells.

Non-alcoholic fatty liver disease and type 2 diabetes are representing symptoms of metabolic syndrome, which is often accompanied with hepatic fat accumulation and insulin resistance. Since liver is the major site of glucose and lipid metabolism, this study aimed to understand the effects of SCAAs and BCAAs supplementations on glucose and lipid metabolism in HepG2 cells. These cells were pretreated with SAMe, betaine, taurine, and BCAA for 24 h, followed by treatments of a high concentration of glucose (50 mM) or palmitic acid (PA, 0.5 mM) for 48 h to simulate high-glucose and high-fat environments. Pretreatment of BCAA and SCAAs inhibited the fat accumulation. At the transcriptional level, glucose and PA treatment led to significant increase of mRNA gluconeogenic enzyme. The mRNA expression level of GLUT2 was decreased by 20% in the SAMe-treated group and inhibited glucose synthesis by reducing the level of gluconeogenic enzyme. After SAMe or BCAA pretreatment, the mRNA expression of lipogenic enzymes was decreased. The PPAR-γ expression was increased after BCAA pretreatment, but SAMe not only downregulated the expression of PPAR-γ, but also inhibited the expression of ChREBP approximately 20% and SREBP-1c decreased by about 15%. Taken together, the effect of SAMe on glucose and lipid metabolism is significant especially on inhibiting hepatic lipogenesis and gluconeogenesis under the metabolic syndrome environment.

Nutritional Supplementation with Amino Acids on Bacterial Cellulose Production by Komagataeibacter intermedius: Effect Analysis and Application of Response Surface Methodology.

Bacterial cellulose (BC) is a biopolymer mainly produced by acetic acid bacteria (AAB) that has several applications in the medical, pharmaceutical, and food industries. As other living organisms, AAB require sources of chemical elements and nutrients, which are essential for their multiplication and metabolite production. So, the knowledge of the nutritional needs of microorganisms that have important industrial applications is necessary for the nutrients to be supplied in the appropriate form and amount. Considering that the choice of different nutrients as nitrogen source can result in different metabolic effects, this work aimed to verify the effects of amino acid supplementation in the culture media for BC production by an AAB strain (Komagataeibacter intermedius V-05). For this, nineteen amino acids were tested, selected, and optimized through a Plackett and Burman factorial design and central composite design to determine the optimal concentrations of each required amino acid. Membranes produced under optimal conditions were characterized in relation to chemical structure and properties by X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), infrared spectroscopy (FT-IR), and hydrophilic properties. Three amino acids had a significant positive effect and were required: aspartic acid (1.5g L-1), phenylalanine (1.5g L-1), and serine (3.0g L-1). Conversely, all sulfur and positively charged amino acids had a negative effect and reduced the production yield. After optimization and validation steps, a production level of 3.02g L-1 was achieved. Membranes produced from optimized media by this strain presented lower crystallinity index but greater thermal and hydrophilic properties than those produced from standard HS medium.

Side effects of amino acid supplements.

The aim of the article is to examine side effects of increased dietary intake of amino acids, which are commonly used as a dietary supplement. In addition to toxicity, mutagenicity and carcinogenicity, attention is focused on renal and gastrointestinal tract functions, ammonia production, and consequences of a competition with other amino acids for a carrier at the cell membranes and enzymes responsible for their degradation. In alphabetic order are examined arginine, beta-alanine, branched-chain amino acids, carnosine, citrulline, creatine, glutamine, histidine, beta -hydroxy- beta -methylbutyrate, leucine, and tryptophan. In the article is shown that enhanced intake of most amino acid supplements may not be risk-free and can cause a number of detrimental side effects. Further research is necessary to elucidate effects of high doses and long-term consumption of amino acid supplements on immune system, brain function, muscle protein balance, synthesis of toxic metabolites, and tumor growth and examine their suitability under certain circumstances. These include elderly, childhood, pregnancy, nursing a baby, and medical condition, such as diabetes and liver disease. Studies are also needed to examine adaptive response to a long-term intake of any substance and consequences of discontinuation of supplementation.

Effect of amino acid supplementation and choline chloride for low protein diet on nitrogen efficiency and methane emission of dairy cows

Ruminants are one of the largest anthropogenic methane and nitrous oxide emissions. Therefore, the hypothesis was to study the effects of reducing dietary crude protein (CP) level on environmental contaminators when rumen-protected amino acids and choline chloride were supplemented. Sixty Holstein dairy cows were used during the experiment. Test diets were: (1) CD = Control diet with16.2 g of crude protein/ Kg of DM); (2) LM = Low protein diet with 14.2 g of crude protein/ Kg of DM + methionine ; (3) LL = Low protein diet with 14.2 g of crude protein/ Kg of DM + lysine; (4) LML = Low protein diet with 14.2 g of crude protein/ Kg of DM + methionine + lysine; (5) LMLC = Low protein diet with 14.2 g of crude protein/ Kg of DM + methionine + lysine + choline. Dry matter and NDF intake were not different, but the control group received higher CP and ADF compared with other groups (P &lt; 0.05). Fecal CP and ADF of control group were lower (P &lt; 0.05), but no differences were observed for fecal dry matter (DM) and NDF. Milk yield and protein content were higher for LML and LMLC like control group (P &lt; 0.05). Nitrogen intake, urinary N, urinary urea N and total excreta N decreased (P &lt; 0.05) when animals fed low protein. There was no difference in ruminal pH and acetate to propionate ratio, whereas the ruminal ammonia-N decreased with the low protein (P &lt; 0.05). The 120-h gas production test, showed no difference on the kinetics of digestion and in vitro methane emission. However, the inclusion of DMI in the calculations revealed that low protein can reduce (P &lt; 0.05) methane emission. Overall, our findings indicated that low protein can be compensated for by adding rumen-protected amino acids, not only to maintain the animal performance, but also to decrease nitrogen excretion and methane emission.

Supplementation of Lysine and Methionine in Milk Replacer or Starter Concentrate for Dairy Calves in Step-Up/Step-Down Feeding Program.

Simple SummaryYoung animals may have limited growth when amino acid (AA) requirements, especially lysine (Lys) and methionine (Met), are not met. However, the requirements of these AA are not well established for dairy calves, and supplementation strategies may vary with the milk feeding program. This study aimed to evaluate supplementation with Lys and Met in a milk replacer (MR) or a starter concentrate (SC) for calves in a step-up/step-down feeding program. Supplementation with Lys and Met did not benefit the dairy calves’ performance or metabolism when fed higher volumes of MR. Further studies are needed to understand the negative effects of AA on calf starter intake.This study aimed to evaluate the performance and metabolic changes in dairy calves fed in a step-up/step-down program and supplemented with lysine and methionine in a milk replacer (MR) or starter concentrate (SC). Male Holstein calves (n = 45) were blocked and distributed in the control without supplementation (1) and with lysine and methionine supplementation in the SC to achieve an intake of 17 and 5.3 g/d, respectively (2), and in the MR to achieve the same daily intake (3). MR was fed 4 L/d until the 2nd week, 8 L/d from the 3rd to 6th week, and 4 L/d from the 7th to 8th week, when calves were weaned. The calves were followed until the 10th week of age. Feed intake was measured daily. Weight and body measurements were registered weekly, and blood samples were collected biweekly. The lysine and methionine intake during the whole period was higher when supplementation occurred via MR. There was a supplementation effect for average daily gain after weaning, and the animals supplemented in the MR had lower BW than those that were not supplemented. Supplementation in MR decreased starter intake at the 10th week and total intake (g DM/d) after weaning. Supplementation with lysine and methionine in the MR or the SC did not benefit the performance or metabolism of dairy calves in the step-up/step-down program. Further studies are needed to understand the effects of amino acid supplementation on feed intake.

Effect of amino acid supplementation, elicitation and LEDs on Hylocereus costaricensis callus culture for the enhancement of betalain pigments

Hylocereus costaricensis more popularly known as the purplish-red pitaya or dragon fruit belongs to the Cactaceae family. The present study analyzes the effect of amino acids, elicitors, and light quality to improve callus proliferation, enhance betalain content and antioxidant profiles through elicitation and amino acid supplementation. The treatments that stimulated the highest total betalain content in red callus cultures were 50 µM tyrosine that produced a 1.6-fold increase (11.28 ± 0.38 mg/g DM) in betalain content and 200 µM leucine that produced 2.56-fold increase (18.13 ± 5.98 mg/g DM) in betalain content. Elicitation of yellow callus cultures with 100 mg/L yeast extract enhanced betalain content by 2-fold without affecting callus biomass. Betalain content could also be improved by 1.23-fold with 20 µM silver nitrate (12.51 ± 0.55 mg/g DM) while callus dry mass and total phenolic content were elevated at 40 µM silver nitrate. The utilization of light was a promising strategy for increased production of secondary metabolites in callus cultures of H. costaricensis. Both yellow and red callus cultures incubated under red LED lights enhanced total betalain content by 3.8- fold (11.64 ± 0.54 mg/g DM) and 4.8-fold (9.42 ± 1.48 mg/g DM), significantly higher (p < 0.01) than cool white LED lights (control treatment). Amino acid supplementation and elicitation strategies in this study achieved betalain content in yellow and red callus that was higher than that in dragon fruit peel (6.31 ± 1.82 mg/g DM), the pulp (3.26 ± 0.26 mg/g DM), and in vitro seedlings (2.01 ± 0.12 mg/g DM). The present investigation reports a simple and efficient protocol for in vitro betalain production from H. costaricensis. This study may enable the future commercial production of betalain compounds under a controlled environment, independent of climate and soil conditions.

Effect of amino acid supplementation and stress on expression of molecular markers in meagre (Argyrosomus regius)

The objectives of this work were: 1) develop of molecular stress biomarkers obtaining sequence data of different transcripts, 2) study the molecular stress response through the expression quantification of key gene involved in it, and 3) assess the effects of dietary amino acid additives on stress response in meagre meagres (Argyrososmus regius). Fish batches were fed two experimental diets with tryptophan (Trp) or aspartate (Asp) added for seven days. Before sampling fish were submitted to confinement/netting stress during 1 h, except control fish. Therefore fish were sampled before and after stress (1 h and 6 h post-stress). The sampling consisted of blood and tissues (brain, hypophysis and liver). Several gene expressions related to the stress response were measured in those tissues, and the cloning of corticotropin-releasing hormone (crh), corticotropin-releasing hormone binding protein (crh-bp), and thyrotropin-releasing hormone (trh) has been reported in meagre for the first time. In fact, fish fed an additional Asp diet did not present any sl, prl and gh expression changes, as for the control group. Contrarily, the Trp diet altered the prl and gh expressions after stress. For crh and crh-bp expressions, no significant differences were detected within the Asp diet hence that amino acid improved the stress response. However, Asp feeding, but not Trp, enhanced pomc-a expression after stress. Hsp70 expression varied for every treatment, including the control feeding, indicating a late response at 6 h post-stress sampling, where both Asp and Trp treatments increased these expressions significantly. Concluding, the response of molecular stress markers to amino acid enriched diets was diverse. The stressor did not change significantly the relative expression of most analyzed genes for control feeding groups, though the Asp supplemented diet was more effective for attenuating molecular markers than the Trp one.

Effects of Amino Acid Supplementation on Liver Lipid Content: A Randomized, Double-Blinded, Placebo-Controlled Trial

Abstract Objectives To test whether chronic ingestion of essential amino acids (EAAs) plus arginine lowers liver lipid content when compared with a placebo (non-essential amino acids; NEAAs). Methods Older adults (50–75 y) with elevated fasting plasma triacylglycerol (TAG) concentrations were recruited into the study. After screening (week -2), all participants ingested placebo (NEAAs; alanine, aspartic acid, and serine) capsules twice daily (between meals) for two weeks and 3 T nuclear magnetic resonance spectroscopy scans were used to determine baseline (week 0) liver lipid percentage. Participants were then randomised to receive capsules containing 11 g of EAAs plus arginine (n = 10) or NEAAs (n = 9) twice daily for eight weeks, using a double-blinded design. Follow-up NMR spectroscopy scans were conducted at eight weeks after the onset of randomised supplementation (week 8) to determine the impact on liver lipids. Results Liver lipid percentage (mean ± standard deviation) was not significantly altered by randomised supplementation in either the EAAs plus arginine group (Pre: 9.08 ± 7.90%; Post: 8.94 ± 6.91%; P = 0.65) or the NEAAs group (Pre: 10.23 ± 7.20%; Post: 9.65 ± 7.70%; P = 0.18). Change in fasting plasma TAG during placebo run-in (Week 0 minus screening) was significantly negatively correlated with change in liver lipid content (week 8 minus week 0) for the EAAs plus arginine group (r = −0.722; P = 0.02), but not for the NEAAs group A (r = −0.479; P = 0.19). Conclusions Eight weeks of essential amino acids plus arginine ingestion did not significantly lower liver lipid content in older adults. However, ingestion of non-essential amino acids during the run-in period may have influenced the effect on liver fat of subsequent randomised amino acid supplementation, suggesting further investigation is warranted. Funding Sources The study was sponsored by NIH/NIA (award to EB), and the Roy and Christine Sturgis Charitable Trust (award to NMH). Screenings and study visits were undertaken within the ITS-Clinical Research Center at UTMB, funded by NIH/NCRR, and within the UAMS Donald W. Reynolds Institute on Aging at UAMS, funded by NIH/NIA. NMH and EB were also funded by the Arkansas Biosciences Institute, the major research component of the Arkansas Tobacco Settlement Proceeds Act of 2000.

Amino acid supplementation for enhancing recombinant protein production in E. coli.

Recombinant protein production (RPP) in Escherichia coli (E. coli) often induces metabolic burden to the cells that compromise their overall growth and productivity. Amino acid starvation due to RPP is a major contributor of the metabolic burden on the cells and induces global stress response known as a stringent-like response. In this study, the effect of amino acid supplementation in a chemically defined medium on cellular growth and recombinant pramlintide production was investigated. Based on the consumption profile, few amino acids were categorized as growth-promoting (GP1) and protein production promoting (GP2). Feeding strategies of GP1 and GP2 were tested in shake flasks followed by scale up into the bioreactor. A 40% increase in the recombinant pramlintide (rPramlintide) production (protein concentration of 3.09 ± 0.12 g/L and yield of 227.69 ± 19.72 mg pramlintide per gram dry cell weight) was realized. Furthermore, transcriptomics data indicated the downregulation of several genes associated with global stress response and genes involved in amino acid biosynthesis in test culture, supported by proteomics analysis. These results signify that the external supply of critical amino acids decreases cellular stress during RPP and improves process productivity.

The effect of amino acid supplementation in an industrial Chinese Hamster Ovary process.

The main goal in biosimilar development is to increase Chinese Hamster Ovary (CHO) viability and productivity while maintaining product quality. Despite media and feed optimization during process development, depletion of amino acids still occurs. The aim of the work was to optimize an existing industrial fed batch process by preventing shortage of amino acids and to gather knowledge about CHO metabolism. Several process outputs were evaluated such as cell metabolism, cell viability, monoclonal antibodies (mAbs) production, and product quality. First step was to develop and supplement an enriched feed containing depleted amino acids. Abundance of serine and glucose increased lactate production resulting in low viability and low productivity. In the next step, we developed an amino acid feed without serine to avoid the metabolic boost. Supplemented amino acids improved cell viability by 9%; however, mAb production did not increase significantly. In the final step, we limited glucose concentration (<5.55 mmol/L) in the cell culture to avoid the metabolic boost while supplementing an amino acid feed including serine. Data analysis showed that we were able to (a) replace depleted amino acids and avoid metabolic boost, (b) increase viability by 12%, (c) enhance mAb production by 0.5 g/L (total by approximately 10 g), and (d) extend the overall process time of an already developed bioprocess.

Effects of Lysine and Methionine supplementation on first antler growth in fallow deer (Dama dama)

• The supplementation of Ruminally Protected Lysine 5 g per animal and day did not improve any antler characteristics • The combination of Lysine 9 g and Methionine 3 g per animal and day increased antler burr perimeter • Amino acids had direct effects on antlers and not mediated by body weight of animals • The positive effect of amino acids on antler properties is more intense in situations when the animals have a lower performance Amino acid supplementation in cervids is an almost unexplored research area. Lysine (Lys) and Methionine (Met) are the two amino acids considered as limiting for ruminants and Lys supplementation shows good potential for increased antler growth as it is the main component of collagen and a bone tissue precursor. However, several studies in other ruminants have shown greater effects when simultaneously supplementing Lys + Met. Two experiments based on Lys and Met supplementation during first antler growth were conducted during two consecutive years. Each experiment involved 45 yearling fallow bucks distributed in three groups, balanced by weight: Exp.1: Pasture , Pasture + Barley (0.2 kg/animal per day), and Pasture + Barley + Lys (5 g/animal per day); Exp.2: Pasture + Barley (0.5 kg/animal per day), Pasture + Barley + Lys (9 g/animal per day), and Pasture + Barley + Lys + Met (9 and 3 g/animal per day, respectively). Lys supplementation during the first experiment did not improve any antler characteristics ( P > 0.05). However, in the second experiment, both Lys (9 g) and Lys + Met treatments had positive effects on the external antler characteristics ( P = 0.013), antler weight ( P = 0.061) and particularly on the burr perimeter ( P = 0.008), which is crucial for antler size in following years. The results also suggest a stronger positive effect of amino acid supplementation on antler growth when the animals have a low performance in the presence of poorer pasturing situation.

Physiological and biochemical response of broiler chickens to amino acids administration

The main objective of this study was to evaluate the effect of amino acids supplementation to drinking water of meat-type broiler chickens on their blood parameters and productive traits. A total of sixty one day old, unsexed broiler chicks were obtained from a local hatchery. They were divided into three treatment groups: control group, and two treatment groups supplemented (via drinking water) with amino acids preparation (Amino-2500 USA Premium Nutrition) at 0.5 and 1.0 g/L, respectively. All chicks were fed a commercial low protein diet containing 19% crude protein and 2900 kcal metabolizable energy per kilogram of the diet. Chicks of the control group was fed the recommended (standard) diet containing 23%crude protein and 3000 kcal of ME/Kg. The duration of the experiment was five weeks. The criteria of productive and physiological responses were live body weight, weight gain, blood plasma protein fractions, plasma lipids (cholesterol, triglycerides, high density lipoprotein (HDL) and low density lipoprotein (LDL). Transaminase (ALT and AST) activity indicative of liver function was measured. Kidney function test in terms of plasma creatinine, urea nitrogen and uric acid were also determined. Results showed that live body weight and weight gain of broiler chickens were significantly increased by AA administration either at three or five weeks of age. At marketing age (5 weeks), birds from the 3rd and 2nd groups achieved heavier body weigh by 32.3 and 26.8% more than the control chickens. Blood plasma total protein, albumin and globulin levels were significantly increased in the AA treatment groups for T3 and T2, respectively as compared to the control chicks. Addition of AA resulted in an obvious increase in the activity of ALT and AST indicative of negative influence of excess AA on livers function-related enzymes, especially with the higher dose of AA (T3).This was also observed for plasma uric acids and creatinine concentrations as end products of protein metabolism. The histological sections from lymphoid organs revealed better histological appearance indicative of better immunity and bird's health. It is concluded that excessive AA administration for broilers fed on low protein diet, could be used to increase live body weight, enhance protein metabolism without negative impacts on blood biochemistry, and improve their immune response. However, further study is needed to assess the cost and the net revenue from AA supplementation.

Effects of Amino Acid Supplements in Plant-based Yellow Perch Diets

High protein distillers dried grains (HP-DDG) were tested in combination with fermented soybean meal (FSBM) or soy protein concentrate (SPC), with and without an essential amino acid complex, to assess utility of these plant protein alternatives in Yellow Perch Perca flavescens diets in a 63-d feeding trial. Four experimental diets were formulated to contain equal amounts of HP-DDG and FSBM or SPC, each with and without essential amino acids and compared to a fish meal/HP-DDG reference diet. Fish that received diets containing SPC displayed the greatest weight gain, feed conversion, and apparent protein digestibility. Weight gain was significantly reduced and feed conversion significantly increased in the diet containing FSBM without essential amino acids. No mortalities or health assessment differences were observed during the trial and all treatment fish readily accepted the experimental diets.

Engineering the Yeast Saccharomyces cerevisiae for the Production of L-(+)-Ergothioneine.

L-(+)-Ergothioneine (ERG) is an unusual, naturally occurring antioxidant nutraceutical that has been shown to help reduce cellular oxidative damage. Humans do not biosynthesise ERG, but acquire it from their diet; it exploits a specific transporter (SLC22A4) for its uptake. ERG is considered to be a nutraceutical and possible vitamin that is involved in the maintenance of health, and seems to be at too low a concentration in several diseases in vivo. Ergothioneine is thus a potentially useful dietary supplement. Present methods of commercial production rely on extraction from natural sources or on chemical synthesis. Here we describe the engineering of the baker's yeast Saccharomyces cerevisiae to produce ergothioneine by fermentation in defined media. After integrating combinations of ERG biosynthetic pathways from different organisms, we screened yeast strains for their production of ERG. The highest-producing strain was also engineered with known ergothioneine transporters. The effect of amino acid supplementation of the medium was investigated and the nitrogen metabolism of S. cerevisiae was altered by knock-out of TOR1 or YIH1. We also optimized the media composition using fractional factorial methods. Our optimal strategy led to a titer of 598 ± 18 mg/L ergothioneine in fed-batch culture in 1 L bioreactors. Because S. cerevisiae is a GRAS (“generally recognized as safe”) organism that is widely used for nutraceutical production, this work provides a promising process for the biosynthetic production of ERG.

Effects of low protein diets with amino acids supplementation on biochemical and faeces parameters in weaned piglets

Effects of low protein diets with amino acids supplementation on biochemical and faeces parameters in weaned piglets