Lactococcus is an economically important group in lactic acid bacteria (LAB) that are often used in the dairy industry as starters for cheese production. Good starter strains should possess the ability to grow, ferment milk sugar, and produce desirable flavor compounds during cheese making. Therefore, it is essential to understand the physiology of these starters during cheese processing in order to obtain high-quality cheese products. Cheese manufacturing compromises several stress factors that affect the growth of starter lactococci. Among these stressed environmental parameters, sugar starvation is the most important one to overcome to obtain energy for cellular processes. It is known that degradation of arginine produces energy. In this study, we investigated arginine utilization by Lactococcus lactis ssp. lactis strain ML3 via the arginine deiminase (ADI) pathway to see its influence on cellular physiology after exhaustion of a primary energy source. During the cell growth in a carbohydrate-limited environment, we observed that metabolic pathways switched between lactose utilization arginine degradation. The statistical model described in this study suggested lactose and arginine were co-metabolized during cell growth. These results initially showed arginine was a good candidate of secondary energy source after exhaustion of primary energy source (lactose). To confirm these observations, cell counts, cellular ATP levels, ADI enzyme activities, and total protein expression were compared in arginine-positive L. lactis ssp. lactis ML3 and arginine-negative L. lactis ssp. cremoris Sl grown in medium containing 0.2% lactose and 2% arginine. Results showed ATP levels remained high in strain ML3, in which a transition stage of protein expression pattern was also observed. This physiological evidence highlights the important roles of arginine degradation in starved ML3, perhaps by producing extra ATP and modulating external pH. The genes involved in the ADI pathway of strain ML3 were cloned, sequenced, and characterized. Genes involved in this pathway formed a unique multi-operon cluster structure that we termed MOC. It was organized as arcA, arcBD1, arcC1C2, and arcTD2. The influence of different environmental parameters including pH, various amino acids, and phosphate (organic and inorganic) on the expression of the ADI MOC was tested. No single factor regulated the entire MOC simultaneously. It is concluded that the unique structure of the MOC appears to allow the ADI pathway to occur in discrete sections in response to fluctuated external conditions, such as sugar starvation and low environmental pH.

Barley, cornstarch, crested wheatgrass, glucose, molasses and solka floc were fermented with rumen fluid obtained from sheep that were adapted or unadapted to feed grade biuret (Kedlor) in their diet. Each rumen fluid and substrate combination was subjected to three nitrogen treatments: (1) control, (2) nitrogen added as feed grade biuret and (3) reagent grade biuret in a factoral arrangement of treatments. In vitro fermentations were terminated at 0, 12, 24, and 36 hours and the protein nitrogen insoluble in trichloroacetic acid (TCA) was determined. Molasses and cornstarch fermentation residues increased while barley, crested wheatgrass, glucose and solka floc decreased in TCA insoluble protein nitrogen. The average of all treatments decreased in TCA insoluble protein nitrogen during the first 12 hours and increased during the remaining 24 hours. Unadapted rumen fluid with simple carbohydrates from glucose and molasses and adapted rumen fluid with complex carbohydrates from barley, crested wheatgrass, cornstarch and solka floc gave the largest gains in TCA insoluble protein nitrogen. No significant differences occurred due to the addition of non-protein nitrogen.

We explored using de-oiled algal biomass (algal cake) as a low-value substrate for production of lactic acid in fermentations with Lactobacillus casei, and strategies for increasing lactic acid production at low pH. L. casei 12A algal cake (AC) fermentations showed carbohydrate and amino acid availability limit growth and lactic acid production. These nutritional requirements were effectively addressed with enzymatic hydrolysis of the AC using α-amylase, cellulase, and pepsin. Producing 0.075 g lactic acid per g AC from AC digested with all three enzymes. We explored heterologous expression of the cellulase gene (celE) from Clostridium thermocellum and the α-amylase gene (amyA) from Streptococcus bovis in L. casei 12A. Functional activity of CelE was not detected, but low-level activity of AmyA was achieved, and increased > 1.5-fold using a previously designed synthetic promoter. Nonetheless, the improvement was insufficient to significantly increase lactic acid production. Thus, substantial optimization of amyA and celE expression in L. casei 12A would be needed to achieve activities needed to increase lactic acid production from AC. We explored transient inactivation of MutS as a method for inducing hypermutability and increasing adaptability of L. casei 12A and ATCC 334 to lactic acid at low pH. The wild type cells and their ΔmutS derivatives were subject to a 100-day adaptive evolution experiment, followed by repair of the ΔmutS lesion in representative isolates. Growth studies at pH 4.0 revealed that all four adapted strains grew more rapidly, to higher cell densities, and produced significantly more lactic acid than untreated wild-type cells. The greatest increases were observed from the adapted ΔmutS derivatives. Further examination of the 12A adapted ΔmutS derivative identified morphological changes, and increased survival at pH 2.5. Genome sequence analysis confirmed transient MutS inactivation decreased DNA replication fidelity, and identified potential genotypic changes in 12A that might contribute to increased acid lactic acid resistance. Targeted inactivation of three genes identified in the adapted 12A ΔmutS derivative revealed that a NADH dehydrogenase (ndh), phosphate transport ATP-binding protein PstB (pstB), and two-component signal transduction system (TCS) quorum-sensing histidine kinase (hpk) contribute to increased acid resistance in 12A.

Improved weight loss interventions are needed to help reduce obesity. One dietary factor that has been effective in increasing weight loss is increased dietary structure. One method for increasing dietary structure is prescribing the frequency in which eating bouts (meals and snacks) occur. Eating frequency (EF) has been inversely related to body mass index (BMI) but the impact of EF on weight loss is unclear. This randomized controlled trial examined the effect of EF on hunger, the relative-reinforcing value of food, energy intake (EI), and weight loss during a 6 month behavioral weight loss intervention. Participants (age: 51.0 ± 9.9 yrs, BMI: 35.5 ± 4.8 kg/m2, 57.8% female, 94.1% white) were randomized to one of two EF prescriptions: 1) Three Meal (n=25): three eating bouts/day; or 2) Grazing (n=26): eat at least 100 kcals every 2-3 hrs. Both groups attended 20 sessions and had identical dietary (1200–1500 kcals/day, < 30% kcals from fat) and physical activity (200 minutes/wk) goals. Hunger, relative-reinforcing value of food, diet, and anthropometric data were collected at 0 and 6 months. Using intent-to-treat analyses, Grazing reported a greater EF (eating bouts in which > 25 kcals were eaten/day) than Three Meal at 6 months (5.8 ± 1.1 eating bouts vs. 3.2 ± 0.6 eating bouts, p<0.001). On a 100-mm visual analogue scale Grazing reported significantly less hunger at 6 months as compared to 0 months (47.9 ± 18.5 mm vs. 56.3 ± 15.7 mm, p<0.05), while Three Meal did not report any changes. There were no significant differences in the relative-reinforcing value of food between groups or over time. EI and BMI were significantly (p<0.001) reduced from 0 to 6 months (EI: 0 months = 2198 ± 692 kcals/day vs. 6 months = 1266 ± 353 kcals/day; BMI: 0 months = 35.5 ± 4.8 kg/m2 vs. 6 months = 30.6 ± 4.9 kg/m2). There were no significant differences in EI or BMI between the groups. An EF of approximately six eating bouts/day may decrease hunger more so than an EF of three meals/day while consuming a low-kcal diet during a behavioral weight loss intervention.

Underreporting in dietary assessment has been linked to dietary restraint (DR) and social desirability (SD). Thus, this study investigated accuracy of reporting energy intake (EI) of a laboratory meal during a 24-hour dietary recall (24HR) in 38 healthy, college-aged (20.3 +/- 1.7 years), normal-weight women (22.4 +/- 1.8 kg/m2), categorized as high or low in DR and SD. Participants consumed a meal (sandwich wrap, chips, fruit, and ice cream) and completed a telephone 24HR. Accuracy of reported intake = (((reported intake - measured intake)/measured intake) x 100) [positive numbers = overreporting]. Overreporting of EI was found in all groups (meal accuracy rate = 43.1 +/- 49.9%). An interaction of SD x individual foods (p < 0.05) occurred. SD-High as compared to SD-Low more accurately reported EI of chips (19.8 +/- 56.2% vs. 117.1 +/- 141.3%, p < 0.05) and ice cream (17.2 +/- 78.2% vs. 71.6 +/- 82.7%, p < 0.05). An effect of SD occurred, where SD-High as compared to SD-Low more accurately reported meal EI (29.8 +/- 48.2% vs. 58.0 +/- 48.8%, p < 0.05). For measured meal EI, an effect of DR occurred where DR-High consumed less than DR-Low (437 +/- 169 kcals vs. 559 +/- 207 kcals, p < 0.05). An interaction of DR x food type (p < 0.05) occurred where DR-High as compared to DR-Low consumed less sandwich wrap (156 +/- 63 kcals vs. 210 +/- 76 kcals, p < 0.05) and ice cream (126 +/-73 kcals vs. 190 +/- 106 kcals, p < 0.05). For reported meal EI, an effect of DR occurred where DR-High reported consuming less than DR-Low (561 +/- 200 kcals vs. 818 +/- 362 kcals, p < 0.05). An interaction of DR x individual foods (p < 0.05) occurred where DR-High reported consuming less ice cream than DR-Low (145 +/- 91 kcals vs. 302 +/- 235 kcals, p < 0.05). Overreporting EI from a laboratory meal was prevalent. However, those high in SD were more accurate in reporting intake, particularly of high-fat foods. Future research is needed to investigate factors that contribute to overreporting.

This investigation examined acute energy compensation and macronutrient intake in habitually active and sedentary, college-aged males, following an exercise session as compared to a resting (control) session, to see if habitually active males compensate intake better to an energy deficit incurred by exercise, than sedentary males. Participants were males, aged 18-30 years, of a normal percent body fat and body mass index, and exercised < 60 min per week (sedentary) or > 150 min per week (habitually active). Participants came in for two sessions: 1) 45 minutes of resting (control) and then eating an ad libitum meal; and 2) riding a cycle ergometer for 45 minutes (exercise) and then eating an ad libitum meal. Sessions were counterbalanced across participants. Energy and macronutrient intake were calculated for the meal and over the remaining part of the day. Sedentary individuals ate significantly less during the meal in the exercise session (which expended a mean of 453.5 kcals across both groups) as compared to the control session (934.8 + 222.0 kcals vs. 1073.9 + 470.3 kcals, p < 0.03), which demonstrated negative energy compensation (-30.6%). The habitually active group showed no significant difference in energy intake between sessions at the meal (1016.8 + 396.7 kcal [control] vs. 1105.6 + 389.2 kcal [exercise]). While the habitually active group showed no significant difference in intake at the meal, the slight increase in intake at the meal in the exercise session demonstrated some energy compensation (19.6%), which was significantly better (p < 0.03) than that in the sedentary group. No differences in macronutrient intake at the meal were found between the sessions. Over the day following the sessions, both groups reported a significant increase in energy intake after the exercise session as compared to the control session (1457.5 + 646.2 kcals vs. 1356.1 + 657.2 kcals, p < 0.04), with no difference in macronutrient intake between the sessions. These results indicate that, although complete acute compensation did not occur, the habitually active group acutely compensated intake significantly more so than the sedentary group, demonstrating better energy regulation ability.

Increasing demographic diversity, persistent health disparities, and ongoing efforts to reduce health care costs have made cultural and linguistic competence in the United States health care system a premier concern. Integral to improving cultural competence in health care is providing health professionals with adequate education and training in cultural competence. For this reason, there has been increasing attention paid by academia across health-related disciplines and by national organizations and governmental health agencies to delineating what cultural competence in education and training entails. Though a multidisciplinary body of literature on developing curricula related to cultural competence for health professionals exists, still lacking from this literature is sufficient input from the dietetic profession. The purpose of this cross-sectional internet-based research was to create a curricular model of core curricular competencies related to cultural competence for the education and training of registered dietitians. A random sample of registered dietitians rated 73 proposed curricular competencies for essentiality on a 7-point Likert-like scale (1 = Not a priority; 7 = Essential). Exploratory principal components analysis (PCA) with Varimax rotation condensed the proposed competencies with similar variances of responses into factors (model domains) and eliminated competencies which accounted for too little or ambiguous variance. Factors were assigned unique labels based on the prevailing themes of their respective competencies and further interpreted in terms of respondent characteristics via multivariate general analysis of variance (MANOVA). Results based on a 17.9% (n=1,090) rate of response produced a model with 69 competencies and 7 domains: Communication and Relationships; Community Collaboration; Disparities and Diversity in Health Care; Information Access, Analysis, and Use; Bias Management; Food Environments; and Models and Definitions. Significant differences in mean factor ratings were detected between respondents who differed by race and by experience working with diverse individuals and groups. This model is representative of existing research on cultural competence, but it is the first unique to dietetics. It may be used by dietetic education and training programs to systematically plan, implement, and evaluate curricula for cultural competence.

This investigation examined acute energy compensation and macronutrient intake in habitually active and sedentary, college-aged males, following an exercise session as compared to a resting (control) session, to see if habitually active males compensate intake better to an energy deficit incurred by exercise, than sedentary males. Participants were males, aged 18-30 years, of a normal percent body fat and body mass index, and exercised < 60 min per week (sedentary) or > 150 min per week (habitually active). Participants came in for two sessions: 1) 45 minutes of resting (control) and then eating an ad libitum meal; and 2) riding a cycle ergometer for 45 minutes (exercise) and then eating an ad libitum meal. Sessions were counterbalanced across participants. Energy and macronutrient intake were calculated for the meal and over the remaining part of the day. Sedentary individuals ate significantly less during the meal in the exercise session (which expended a mean of 453.5 kcals across both groups) as compared to the control session (934.8 + 222.0 kcals vs. 1073.9 + 470.3 kcals, p < 0.03), which demonstrated negative energy compensation (-30.6%). The habitually active group showed no significant difference in energy intake between sessions at the meal (1016.8 + 396.7 kcal [control] vs. 1105.6 + 389.2 kcal [exercise]). While the habitually active group showed no significant difference in intake at the meal, the slight increase in intake at the meal in the exercise session demonstrated some energy compensation (19.6%), which was significantly better (p < 0.03) than that in the sedentary group. No differences in macronutrient intake at the meal were found between the sessions. Over the day following the sessions, both groups reported a significant increase in energy intake after the exercise session as compared to the control session (1457.5 + 646.2 kcals vs. 1356.1 + 657.2 kcals, p < 0.04), with no difference in macronutrient intake between the sessions. These results indicate that, although complete acute compensation did not occur, the habitually active group acutely compensated intake significantly more so than the sedentary group, demonstrating better energy regulation ability.

Underreporting in dietary assessment has been linked to dietary restraint (DR) and social desirability (SD). Thus, this study investigated accuracy of reporting energy intake (EI) of a laboratory meal during a 24-hour dietary recall (24HR) in 38 healthy, college-aged (20.3 +/- 1.7 years), normal-weight women (22.4 +/- 1.8 kg/m2), categorized as high or low in DR and SD. Participants consumed a meal (sandwich wrap, chips, fruit, and ice cream) and completed a telephone 24HR. Accuracy of reported intake = (((reported intake - measured intake)/measured intake) x 100) [positive numbers = overreporting]. Overreporting of EI was found in all groups (meal accuracy rate = 43.1 +/- 49.9%). An interaction of SD x individual foods (p < 0.05) occurred. SD-High as compared to SD-Low more accurately reported EI of chips (19.8 +/- 56.2% vs. 117.1 +/- 141.3%, p < 0.05) and ice cream (17.2 +/- 78.2% vs. 71.6 +/- 82.7%, p < 0.05). An effect of SD occurred, where SD-High as compared to SD-Low more accurately reported meal EI (29.8 +/- 48.2% vs. 58.0 +/- 48.8%, p < 0.05). For measured meal EI, an effect of DR occurred where DR-High consumed less than DR-Low (437 +/- 169 kcals vs. 559 +/- 207 kcals, p < 0.05). An interaction of DR x food type (p < 0.05) occurred where DR-High as compared to DR-Low consumed less sandwich wrap (156 +/- 63 kcals vs. 210 +/- 76 kcals, p < 0.05) and ice cream (126 +/-73 kcals vs. 190 +/- 106 kcals, p < 0.05). For reported meal EI, an effect of DR occurred where DR-High reported consuming less than DR-Low (561 +/- 200 kcals vs. 818 +/- 362 kcals, p < 0.05). An interaction of DR x individual foods (p < 0.05) occurred where DR-High reported consuming less ice cream than DR-Low (145 +/- 91 kcals vs. 302 +/- 235 kcals, p < 0.05). Overreporting EI from a laboratory meal was prevalent. However, those high in SD were more accurate in reporting intake, particularly of high-fat foods. Future research is needed to investigate factors that contribute to overreporting.

Diabetes is increasing globally and nationally. Diabetes complications and costs can be reduced through modification of lifestyle risks and diabetes self-management education (DSME). The Cooperative Extension System (CES) is uniquely positioned to implement DSME. This study assessed the role and impact of the Cooperative Extension System (CES) in DSME. A survey was sent to CES professionals throughout the U.S. a total of 43 participants provided information on 73 DSME programs. Most participants were from the South (n=22, 51.16%) and Midwest (n=12, 27.91%) and most programs targeted adults with and at risk for type 2 diabetes. Most programs were developed and taught by registered dietitians and family and consumer science agents and were focused on healthy eating and cooking techniques. Few programs addressed medications, mental and physical health, influenza and pneumococcal vaccinations. Implementation challenges were related to recruitment, attrition, and funding and most suggestions for the future of CES in DSME were related to funding. CES has a wide reach in terms of DSME with over 29 states. Future CES efforts should target children with type 2 diabetes and should form/continue partnerships with health care professionals.