Spent Yeast from Brewing Processes: A Biodiverse Starting Material for Yeast Extract Production

Spent yeast from beer manufacturing is a cost-effective and nutrient-rich starting material for the production of yeast extracts. In this study, it is shown how physiologically important ingredients in a yeast extract are influenced by the composition of the spent yeast from the brewing process. In pilot fermentations, the time of cropping (primary fermentation, lagering) of the spent yeast and the original gravity (12 ˚P, 16 ˚P, 20 ˚P) of the fermentation medium was varied, and four alternative non-Saccharomyces yeast strains were compared with two commercial Saccharomyces yeast strains. In addition, spent yeast was contaminated with the beer spoiler Lactobacillus brevis. The general nutrient composition (total protein, fat, ash) was investigated as well as the proteinogenic amino acid spectrum, the various folate vitamers (5-CH3-H4folate, 5-CHO-H4folate, 10-CHO-PteGlu, H4folate, PteGlu) and the biological activity (reduction, antioxidative potential) of a mechanically (ultrasonic sonotrode) and an autolytically produced yeast extract. All the investigated ingredients from the yeast extract were influenced by the composition of the spent yeast from the brewing process. The biodiversity of the spent yeast from the brewing process therefore directly affects the content of physiologically valuable ingredients of a yeast extract and should be taken into consideration in industrial manufacturing processes

Comparison of Raman and Mid-Infrared Spectroscopy for Real-Time Monitoring of Yeast Fermentations: A Proof-of-Concept for Multi-Channel Photometric Sensors

Raman and mid-infrared (MIR) spectroscopy are useful tools for the specific detection of molecules, since both methods are based on the excitation of fundamental vibration modes. In this study, Raman and MIR spectroscopy were applied simultaneously during aerobic yeast fermentations of Saccharomyces cerevisiae. Based on the recorded Raman intensities and MIR absorption spectra, respectively, temporal concentration courses of glucose, ethanol, and biomass were determined. The chemometric methods used to evaluate the analyte concentrations were partial least squares (PLS) regression and multiple linear regression (MLR). In view of potential photometric sensors, MLR models based on two (2D) and four (4D) analyte-specific optical channels were developed. All chemometric models were tested to predict glucose concentrations between 0 and 30 g L−1, ethanol concentrations between 0 and 10 g L−1, and biomass concentrations up to 15 g L−1 in real time during diauxic growth. Root-mean-squared errors of prediction (RMSEP) of 0.68 g L−1, 0.48 g L−1, and 0.37 g L−1 for glucose, ethanol, and biomass were achieved using the MIR setup combined with a PLS model. In the case of Raman spectroscopy, the corresponding RMSEP values were 0.92 g L−1, 0.39 g L−1, and 0.29 g L−1. Nevertheless, the simple 4D MLR models could reach the performance of the more complex PLS evaluation. Consequently, the replacement of spectrometer setups by four-channel sensors were discussed. Moreover, the advantages and disadvantages of Raman and MIR setups are demonstrated with regard to process implementation

The manifestation of personal philosophies concerning material and form

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Transformation in governance towards resilient food systems

The dynamics of systemic societal transformations are not well understood, and the extent to which such transformations can be governed is contested. This research paper is the result of a joint effort among a small group of researchers to identify pathways for transformation towards sustainable food systems, which are resilient towards shocks and towards climate change in particular. Using empirical studies, both transformations in governance systems and governance of transformations were investigated. These cases served as a preliminary analysis to identify some of the trends and patterns that warrant further investigation. Not surprisingly, transformational change in food systems is often triggered by a shock to the system, or by increasing pressure to that system. But that alone is not enough to bring about a transformation. A number of preconditions and conditions need to be present including sufficient ‘wealth’ or economic and social capital in the system with resources that can be mobilized, and sufficient flexibility in the institutional context to allow innovation to emerge and gain strength. A particular area of interest that appears to stimulate transformations is collective action, which often involves collaboration across geographical scales and interest groups. The outcomes of transformations are complex and typically multifaceted, and can take years to emerge. However, broadly speaking, the cases explored demonstrate that governance is central to food system transformation both in terms of pre-conditions and provoking processes as well as in the outcomes of the transformation itself. Food system transformations in general appear to entail fundamental shifts in social relations and institutions – in other words, the governance of the food system

Comparing validation of four ELISAsystems for detection of Salmonella Derby- and Salmonella Infantis-infected pigs

The objective of this study was the comparative evaluation of four indirect Salmonella ELISA tests at study time approved in Germany to detect Salmonella infection in pigs. Three tests are based on a LPS-antigen mix and directed against specific IgG antibodies. The fourth test is based on a purified S. Typhimurium whole-cell lysate antigen and discriminates between Salmonella- specific IgM-, IgA-, and IgG- antibodies. In a longitudinal study, two groups of six weeks old hybrid piglets were orally infected with a porcine S. Infantis or S. Derby strain. Clinical and bacteriological parameters were monitored weekly during an observation period of 130 days after infection and serum samples were investigated in parallel with the respective ELISAs. Apparently, the LPS-based ELISA systems used in this study failed to recognize S. Infantis-infected pigs although those animals shed the pathogen in high amounts throughout the study until day 81 post infection (p. i.). In contrast, the isotype-specific Salmonella Typhimurium whole-cell-lysate based ELISA was capable of detecting Salmonella-infected pigs from day ten p. i. at all tested serotypes and revealed the highest sensitivity in detection of S. Infantis- infected pigs. Furthermore, it became apparent that the often used surveillance cut-off value of 40 OD% is not appropriate for intra-vitam detection of S. Infantis- and S. Derbyinfected pigs. In contrast, the cut-off values of the ELISAs given by the suppliers result in considerable higher detection rates

The relationship between organizational culture and the implementation of response to intervention in one elementary school

This study investigated the relationship between organizational culture and the implementation of Response to Intervention in one elementary school. It examined issues corresponding to change within a system, with particular attention to those relating to school culture. An ethnographic approach was used to gather data, including the collection of artifacts, observations, and interviews. This study found that the implementation of RTI presents numerous organizational, school culture, and leadership challenges. At the organizational level, RTI affects the entire district by changing the instructional focus to include early intervening services and the process by which students are found eligible for special education. This impacts multiple aspects of the school: scheduling, the use of instructional staff, student placement in classes, budget issues, and professional development for staff. These organizational issues present a significant challenge for a district facing a serious financial crisis. School culture plays a significant role in what is valued by the organization. Schools are a collection of individuals and their relationships with others. It is through these relationships and shared understanding that school culture is preserved. The school culture at Newberry is one of collaboration and teamwork; the irrelationships and shared values led to the successful implementation of RTI. Schools are a microcosm of the community. While schools share numerous elements, each school culture is unique. To understand a group of people, it is important to understand the contextual elements that influence individual and institutional behaviors (Schein, 1992). The village of Newberry has a unique history of rugged pioneerism and an interdependent relationship with state institutions that has influenced the school culture. The staff was able to recognize the cultural and economic benefits of state institutions and their influence on the make-up of the community and school population, which resulted in a school climate conducive to implementing RTI. This study found that school leadership plays a significant role in the implementation of RTI. Newmann (1996) found that in the majority of schools studied, the school’s ability to sustain new practices was largely dependent on the principal’s leadership. This study found that one reason the staff at Newberry was able to successfully implement RT I was the support and leadership from the school administration

Efficacy of a competitive exclusion culture against extended-spectrum β-lactamase-producing Escherichia coli strains in broilers using a seeder bird model

Background Administration of a competitive exclusion culture (CE culture) has the potential to induce protective effects in very young chicks against caecal colonisation by EEC (= extended-spectrum β-lactamases [ESBL] and AmpC-type [AmpC] beta-lactamases producing Escherichia coli). The study aimed to verify the protective capacity of a CE culture in broilers using the seeder bird model against EEC exposure of the chicks. Results Introduction of infected seeder birds resulted in rapid and strong caecal colonisation of four different EEC challenge strains tested in untreated contact broilers. Compared to controls the broilers pre-treated with the CE culture showed a considerable decrease in caecal load of different EEC challenge strains from about 3.0–3.5 log10 units (P < 0.05) on day 9 of life to 2.5–3.0 log10 units (P < 0.05) on day 37. A slightly higher protective level of the CE culture in layer birds than in broilers raises the question on reasons for possible differences in the efficacy of CE culture in broiler and layer breeds. Whether the diet’s protein content has an impact on both normal intestinal flora composition and the efficacy of CE cultures against EEC or other pathogens remains open and needs further elucidation. Conclusions Our findings suggest that CE cultures of undefined composition can be valuable to reduce the intestinal colonisation by EEC in newly hatched broilers

Efficacy of a competitive exclusion culture against extended-spectrum β-lactamase-producing Escherichia coli strains in broilers using a seeder bird model

Background Administration of a competitive exclusion culture (CE culture) has the potential to induce protective effects in very young chicks against caecal colonisation by EEC (= extended-spectrum β-lactamases [ESBL] and AmpC-type [AmpC] beta-lactamases producing Escherichia coli). The study aimed to verify the protective capacity of a CE culture in broilers using the seeder bird model against EEC exposure of the chicks. Results Introduction of infected seeder birds resulted in rapid and strong caecal colonisation of four different EEC challenge strains tested in untreated contact broilers. Compared to controls the broilers pre-treated with the CE culture showed a considerable decrease in caecal load of different EEC challenge strains from about 3.0–3.5 log10 units (P < 0.05) on day 9 of life to 2.5–3.0 log10 units (P < 0.05) on day 37. A slightly higher protective level of the CE culture in layer birds than in broilers raises the question on reasons for possible differences in the efficacy of CE culture in broiler and layer breeds. Whether the diet’s protein content has an impact on both normal intestinal flora composition and the efficacy of CE cultures against EEC or other pathogens remains open and needs further elucidation. Conclusions Our findings suggest that CE cultures of undefined composition can be valuable to reduce the intestinal colonisation by EEC in newly hatched broilers