Safety assessment of the biotechnologically produced human-identical milk oligosaccharide 3-Fucosyllactose (3-FL).

3-Fucosyllactose (3-FL), a highly abundant complex carbohydrate in human breast milk, functions as a prebiotic promoting early microbial colonization of the gut, increasing pathogen resistance and modulating immune responses. To investigate potential health benefits, 3-FL was produced by fermentation using a genetically modified E. coli K12 strain. The safety assessment of 3-FL included acute oral toxicity, in vitro and in vivo assessment of genetic toxicity, and a subchronic rodent feeding study. 3-FL was not acutely toxic at 5000 mg/kg bw, and there was no evidence of genetic toxicity in the bacterial reverse mutation test and chromosomal aberration assay. There was a repeatable statistically-significant trend in the 4-h S9-activated test conditions in the in vitro micronucleus assay; the confirmatory in vivo mouse micronucleus study was negative at all doses. Dietary subchronic exposure of rats to 3-FL (5% and 10%) did not produce any statistical or biologically-relevant differences in growth, food intake or efficiency, clinical observations, or clinical or anatomic pathology changes at average daily intakes of 5.98 and 7.27 g/kg bw/day for males and females, respectively. The weight of evidence from these studies support the safe use of 3-FL produced using biotechnology as a nutritional ingredient in foods.

Effects of consuming a high-protein diet with or without soy protein during weight loss and maintenance: a non-inferiority, randomized clinical efficacy trial.

OBJECTIVE: This 12-month randomized, non-inferiority clinical trial sought to determine the impact of consuming soy protein as part of an energy-restricted, high-protein diet on weight loss, body composition and cardiometabolic health. METHODS: Seventy-one adults (58 female) with overweight or obesity (body mass index: 32.9 ± 3.6 kg m-2) were randomly assigned to consume three servings of soy (S) or non-soy (NS) protein foods per day for 12 months. All participants completed a group-based behavioural weight loss program lasting 4 months (M4), and follow-up assessments were completed at month 12 (M12). RESULTS: Body weight was reduced in both groups at M4 (S: -7.0% ± 5.2%, NS: -7.1% ± 5.7%) and M12 (S: 3.6% ± 5.1%, NS: -4.8% ± 7.3%). Body weight reductions (mean difference [90% confidence interval]) were not different between S and NS at either time point (M4: -0.16% [-1.4, 3.6], P = 0.90; M12: 1.1% [-1.4, 3.6], P = 0.44). Differences in body fat mass loss were not different between S and NS at M4 (0.29 ± 0.84 kg, P = 0.73) or M12 (0.78 ± 1.5 kg, P = 0.59). Weight loss-induced improvements in cholesterol, triglycerides and blood pressure did not differ between S and NS. CONCLUSION: These results indicate that soy-based protein foods can be effectively incorporated into an energy-restricted, high-protein diet for improving body weight, body composition and cardiometabolic health.

Kinetic regulation of hexokinase activity in a heterogeneous branched bienzyme system.

The kinetic behaviour of a heterogeneous branched bienzyme system of beta-D-glucose oxidase and hexokinase on glucose has been studied. In this sequence, hexokinase is inhibited by its product glucose 6-phosphate and also by D-gluconic acid produced from the parallel enzymic reaction of glucose oxidase. Effect of glucose concentrations on the product's distribution in branched pathway of the bienzyme system is dependent on the kinetic properties of hexokinase and glucose oxidase. Product inhibitions, which are also pH dependent, have a strong regulatory role on the reaction flux.

Elevated leptin concentrations in pregnancy and lactation: possible role as a modulator of substrate utilization.

Energy needs are increased during pregnancy and lactation. These increased energy needs may be met through partitioning of nutrients for energy utilization which is under hormonal control. The objective of the present studies was to determine if changes in plasma leptin occurred during pregnancy and lactation and if the changes were related to prolactin. Plasma leptin and prolactin were measured longitudinally in 9 women through pregnancy and lactation. In a second study, leptin and prolactin were measured 4 days and 28 days postpartum in 21 lactating women. Mean plasma leptin during the three trimesters of pregnancy was significantly higher (29.3+/-2.8 ng/ml) when compared to mean leptin during the three time periods of lactation (19.3+/-3.2 ng/ml) and control groups (9.8+/-1.4 ng/ml). Plasma leptin was elevated early in pregnancy and remained elevated throughout pregnancy. In the second study, the mean plasma leptin in the lactating women was significantly higher 4 days postpartum (17.3+/-3.7 ng/ml) and 28 days postpartum (19.2+/-3.9 ng/ml) when compared to controls (11.6+/-1.2 ng/ml). Prolactin in the control subjects (24+/-4 ng/ml) was significantly lower than in the pregnant (202+/-16 ng/ml) and lactating (108+/-26 ng/ml) groups. Similar observations were made in the second study (controls 20+/-2 ng/ml; lactation 28 days 159+/-21 ng/ml). Leptin during lactation was lower than in pregnancy but higher than control subjects. Regression analysis suggested that BMI and prolactin can be used as predictors of leptin in pregnancy and lactation. The increase in leptin and prolactin early in pregnancy suggests an association between the two hormones. Results of the present studies and research done by other investigators presents a strong role for leptin during pregnancy and lactation. Leptin is regulated by factors other than adiposity especially in reproductive women leading to our hypothesis that there are leptin and prolactin mediated effects on substrates used for energy utilization during pregnancy and lactation.

Role of rusticyanin in the electron transport process in Thiobacillus ferrooxidans.

Effect of diethyl dithiocarbamate (DEDC), an antimicrobial agent, on growth of Thiobacillus ferrooxidans, possibly by inhibiting rusticyanin present in the periplasmic space of the microorganism, has been studied to gain more insight into the electron transport chain in the bioleaching process. DEDC is found to form a stable complex with rusticyanin in solution and also in polyacrylamide gel. The spectrum of the complex is identical to that of Cu-DEDC complex, suggesting binding of DEDC with copper moiety of rusticyanin and resulting in inhibition of growth. In vitro reduction of purified rusticyanin by Fe(II) in absence of acid-stable cytochrome c is very slow, indicating the importance of cytochrome c in electron transport. Thus, in the iron oxidation process, acid-stable cytochrome c is the primary acceptor of electron, transferring the electron to rusticyanin at pH 2.0, which, in turn, affects electron transfer to iron-cytochrome c reductase around pH 5.5.

Soy-dairy protein blend and whey protein ingestion after resistance exercise increases amino acid transport and transporter expression in human skeletal muscle.

Increasing amino acid availability (via infusion or ingestion) at rest or postexercise enhances amino acid transport into human skeletal muscle. It is unknown whether alterations in amino acid availability, from ingesting different dietary proteins, can enhance amino acid transport rates and amino acid transporter (AAT) mRNA expression. We hypothesized that the prolonged hyperaminoacidemia from ingesting a blend of proteins with different digestion rates postexercise would enhance amino acid transport into muscle and AAT expression compared with the ingestion of a rapidly digested protein. In a double-blind, randomized clinical trial, we studied 16 young adults at rest and after acute resistance exercise coupled with postexercise (1 h) ingestion of either a (soy-dairy) protein blend or whey protein. Phenylalanine net balance and transport rate into skeletal muscle were measured using stable isotopic methods in combination with femoral arteriovenous blood sampling and muscle biopsies obtained at rest and 3 and 5 h postexercise. Phenylalanine transport into muscle and mRNA expression of select AATs [system L amino acid transporter 1/solute-linked carrier (SLC) 7A5, CD98/SLC3A2, system A amino acid transporter 2/SLC38A2, proton-assisted amino acid transporter 1/SLC36A1, cationic amino acid transporter 1/SLC7A1] increased to a similar extent in both groups (P < 0.05). However, the ingestion of the protein blend resulted in a prolonged and positive net phenylalanine balance during postexercise recovery compared with whey protein (P < 0.05). Postexercise myofibrillar protein synthesis increased similarly between groups. We conclude that, while both protein sources enhanced postexercise AAT expression, transport into muscle, and myofibrillar protein synthesis, postexercise ingestion of a protein blend results in a slightly prolonged net amino acid balance across the leg compared with whey protein.

A soy, whey and caseinate blend extends postprandial skeletal muscle protein synthesis in rats.

BACKGROUND & AIMS: Blends of dairy and soy protein are used in commercial sports nutrition products; however, no studies have systematically compared blends to isolated protein sources and their effects on muscle protein synthesis (MPS). Dairy whey protein (WP), soy protein isolate (SP), and two blends (Blend 1 and Blend 2) consisting of ratios of 50:25:25 and 25:50:25 for whey:caseinate:soy, respectively, were evaluated for their ability to affect MPS. METHODS: Male Sprague-Dawley rats were trained to eat 3 meals/day: a 4 g meal at 0700-0720 hours followed by ad lib feeding at 1300-1400 hours and 1800-1900 hours. After ~5 days of training, fasted rats were administered their respective 4 g meal at 0700-0720 hours and an intravenous flooding dose of (2)H5-phenylalanine 10 min prior to euthanasia. Individual rats were euthanized at designated postprandial time points. Blood and gastrocnemius samples were collected and the latter was used to measure mixed muscle protein fractional synthetic rates (FSR). RESULTS: Plasma leucine concentrations peaked in all groups at 90 min and were still above baseline at 300 min post-meal. FSR tended to increase in all groups post-meal but initial peaks of FSR were different times (45, 90 and 135 min for WP or SP, Blend 1 and Blend 2, respectively). Blend 2 had a significantly higher FSR compared to WP alone at 135 min (P < 0.05). CONCLUSIONS: Single source proteins and protein blends all enhance skeletal MPS after a meal, however, Blend 2 had a delayed FSR peak which was significantly higher than whey protein at 135 min.

Effects of duration of treatment and dosage of eicosapentaenoic acid and stearidonic acid on red blood cell eicosapentaenoic acid content.

OBJECTIVE: The purpose of this randomized, controlled, parallel group study was to characterize the relationships between dosages of stearidonic acid (SDA) and eicosapentaenoic acid (EPA), and incorporation of EPA into red blood cell (RBC) membranes over time. METHODS: Healthy subjects (n=131) received capsules with placebo (safflower oil), SDA (0.43, 1.3, 2.6, or 5.2 g/d) or EPA (0.44, 1.3, or 2.7 g/d) for 12 weeks. RBC fatty acids were analyzed biweekly. RESULTS: RBC %EPA increased in all EPA and SDA groups (p<0.02 vs. control) except the 0.43 g/d SDA group (p=0.187). For theoretical intakes of EPA of 0.25, 0.5, and 0.89 g/d, the amounts of SDA needed to achieve equivalent RBC EPA enrichment were 0.61, 1.89, and 5.32 g/d (conversion efficiencies of 41%, 26%, and 17%), respectively. CONCLUSIONS: SDA increased RBC %EPA in a dosage and time-dependent manner at intakes as low as 1.3 g/d.

Isolation and purification of protease from human placenta by foam fractionation.

The effect of operating parameters like pH, protein concentration, column geometry, and gas flow rate on the separation efficiency of proteolytic enzymes from crude human placental homogenate has been studied in a batch foam column. Purification has been found to be optimum at pH 8.0, close to the isoelectric pH, at which the surface adsorption of the protein on the foam bubbles is maximum. Both purification and recovery varied significantly with total protein concentration. Stable bubble formation was hindered at lower protein concentrations, while extraneous proteins rather than the protease were preferentially adsorbed at higher protein concentrations, decreasing the purification efficiency. Column diameter and column height should be optimized for any specific feed protein concentration and gas flow rate. However, the enrichment ratio was found to decrease with the increase in flow rate. The results indicate that foam fractionation is an effective separation process for recovering valuable biochemicals from biological materials.

Process engineering studies on immobilized trypsin using molecular sieves as carriers.

In the present investigation molecular sieve has been found to be a suitable carrier for the immobilization of enzymes. From the present study it may be specifically found that trypsin and pappain can be immobilized by molecular sieve type 4a following a very simple techniqure. The immobilized enzyme can be used both in packed as well as in a continuous stirred tank reactor (CSTR).