The Relationship Between Wort Sugar Concentration and Yeast Carbon Partitioning during Brewing Fermentations

High gravity (HG) and very high gravity (VHG) fermentations are increasingly attractive within the brewing industry as a means of optimizing process efficiency and energy-saving. However, the use of highly concentrated worts is concomitant with a number of biological stress factors that can impact on yeast quality and fermentation performance. In order to eliminate or reduce potentially detrimental effects, brewing yeast respond to their environment by shunting carbon into different metabolic end products, which assist in the protection of cells, but also impact on final ethanol yield. The purpose of this research was to investigate the impact of substrate sugar concentration on carbon partitioning in brewing fermentations. This was conducted using a series of laboratory-scale fermentations with worts of 13°P, 18°P and 24°P, pitched using lager and ale yeast strains. Fermentation performance was assessed with respect to the uptake of wort sugars and the production of key carbon-based metabolites, leading to a calculation of yeast central carbon flux. Analysis of carbon assimilation and dissimilation revealed that changes in intracellular trehalose, glycogen, higher alcohols and esters were observed, however the production of yeast biomass acted as the major trade-off with ethanol production. The data presented here shows for the first time the requirements of yeast populations during HG and VHG conditions and the factors that have a major impact on key performance indicators. This data has major significance for fermentation-based industries globally and is especially important for those sectors seeking to maximize yield from existing resources through high gravity fermentations

The impact of extracellular osmolality on Saccharomyces yeast populations during brewing fermentations

Osmotic stress represents one of the major environmental challenges experienced by yeast during industrial 15 fermentations. This stress is particularly associated with high gravity processes which utilise concentrated 16 substrates to yield products with elevated concentrations of ethanol. The aims of this work were to quantitatively 17 measure factors affecting extracellular osmotic pressure (osmolality) during brewing fermentations, and to 18 determine their effects on yeast at the physiological and molecular level. Osmolality was observed to increase 19 during fermentation due predominantly to ethanol production, indicating a strong relationship between these 20 environmental parameters. High osmolality was shown to have a negative impact on yeast physiology, viability 21 and vitality and although genome integrity was unaffected, cell membrane fluidity became altered. This data not 22 only demonstrates the occurrence of an increase in osmotic pressure during fermentation, but provides 23 explanation for the decrease in yeast quality typically observed under high gravity conditions. The results 24 presented here are directly relevant to all brewery fermentations worldwide and have applications within 25 associated industries where microorganisms are used for ethanol production, including food products, alcoholic 26 beverages and biofuels

Reflections on "Campus MOOC" Based on Network Teaching Platform

Abstract: MOOC has attracted global attention in colleges and universities. "Campus MOOC" combines traditional classroom teaching and the advantages of MOOC, the traditional classroom and online learning network to develop teaching by "Flipped Classroom" and blended teaching methods. This paper makes analysis on the factors influencing "Campus MOOC" from the aspects of teachers' information technology teaching ability, students' learning attitude and technology learning ability and supporting policies of the universities. This paper researches how to develop "campus MOOC" from the viewpoint of resource organization of classroom teaching, activities of teachers and students activities, and interactive mode and other aspects

Analysis on the Cultivation of Modern Chinese Farmers’ Values from the Perspective of Traditional Political Culture

Farmers in traditional China have formed the cultural psychology of being reluctant to move from native land and hate to change during the long-term closed production and life. This has exerted negative effect on the values cultivation of farmers today, who possess weak democratic consciousness, low legal spirit and cultural quality as well as strong antagonistic psychology. Measures should be carried out to cultivate their modern values. Firstly, construction of villagers’ self-governance system should be stressed. Secondly, political socialization should be perfected to improve farmers’ political culture. Furthermore, channels of political participation should be widened in order to gradually promote the ordered political participation of farmers

Rural Cultural Construction in the Context of a Harmonious Society

Strengthening rural cultural construction is the objective requirement of building socialist new countryside, is the demand for promoting rural cultural and ethical progress, and of great significance to promotion of rural economic and social development and building of a moderately prosperous countryside. Rural cultural construction is beset with many problems: (1) unbalance in development of rural cultural construction; (2) mistaken ideas in understanding; (3) negative influence of traditional culture; (4) negative effect of market economy; (5) rural education is backward, and science and technology are free from rural production and life. In line with these problems, it comes up with following countermeasures: (1) bringing government functions into full play; (2) carrying forward excellent ethnic cultural tradition and learning all outstanding civilization achievements; (3) enhancing elementary education and energetically developing science and technology; (4) reinforcing rural democratic and legal construction, and guiding farmers to set up socialist democratic and legal awareness; (5) stimulating cultural subject awareness of farmers and enhancing their enthusiasm for participation in cultural construction; (6) cultivating personnel and bringing up a qualified rural cultural backbone team