Yeast Protein as an Easily Accessible Food Source

In recent years, the awareness and willingness of consumers to consume healthy food has grown significantly. In order to meet these needs, scientists are looking for innovative methods of food production, which is a source of easily digestible protein with a balanced amino acid composition. Yeast protein biomass (single cell protein, SPC) is a bioavailable product which is obtained when primarily using as a culture medium inexpensive various waste substrates including agricultural and industrial wastes. With the growing population, yeast protein seems to be an attractive alternative to traditional protein sources such as plants and meat. Moreover, yeast protein biomass also contains trace minerals and vitamins including B-group. Thus, using yeast in the production of protein provides both valuable nutrients and enhances purification of wastes. In conclusion, nutritional yeast protein biomass may be the best option for human and animal nutrition with a low environmental footprint. The rapidly evolving SCP production technology and discoveries from the world of biotechnology can make a huge difference in the future for the key improvement of hunger problems and the possibility of improving world food security. On the market of growing demand for cheap and environmentally clean SPC protein with practically unlimited scale of production, it may soon become one of the ingredients of our food. The review article presents the possibilities of protein production by yeast groups with the use of various substrates as well as the safety of yeast protein used as food.

The budding yeast protein Chl1p is required for delaying progression through G1/S phase after DNA damage

Background The budding yeast protein Chl1p is a nuclear protein required for sister-chromatid cohesion, transcriptional silencing, rDNA recombination, ageing and plays an instrumental role in chromatin remodeling. This helicase is known to preserve genome integrity and spindle length in S-phase. Here we show additional roles of Chl1p at G1/S phase of the cell cycle following DNA damage. Results G1 arrested cells when exposed to DNA damage are more sensitive and show bud emergence with faster kinetics in chl1 mutants compared to wild-type cells. Also, more damage to DNA is observed in chl1 cells. The viability falls synergistically in rad24chl1 cells. The regulation of Chl1p on budding kinetics in G1 phase falls in line with Rad9p/Chk1p and shows a synergistic effect with Rad24p/Rad53p. rad9chl1 and chk1chl1 shows similar bud emergence as the single mutants chl1, rad9 and chk1. Whereas rad24chl1 and rad53chl1 shows faster bud emergence compared to the single mutants rad24, rad53 and chl1. In presence of MMS induced damage, synergistic with Rad24p indicates Chl1p’s role as a checkpoint at G1/S acting parallel to damage checkpoint pathway. The faster movement of DNA content through G1/S phase and difference in phosphorylation profile of Rad53p in wild type and chl1 cells confirms the checkpoint defect in chl1 mutant cells. Further, we have also confirmed that the checkpoint defect functions in parallel to the damage checkpoint pathway of Rad24p. Conclusion Chl1p shows Rad53p independent bud emergence and Rad53p dependent checkpoint activity in presence of damage. This confirms its requirement in two different pathways to maintain the G1/S arrest when cells are exposed to damaging agents. The bud emergence kinetics and DNA segregation were similar to wild type when given the same damage in nocodazole treated chl1 cells which establishes the absence of any role of Chl1p at the G2/M phase. The novelty of this paper lies in revealing the versatile role of Chl1p in checkpoints as well as repair towards regulating G1/S transition. Chl1p thus regulates the G1/S phase by affecting the G1 replication checkpoint pathway and shows an additive effect with Rad24p for Rad53p activation when damaging agents perturb the DNA. Apart from checkpoint activation, it also regulates the budding kinetics as a repair gene.

The budding yeast protein Chl1p is required for delaying progression through G1/S phase after DNA damage.

Background: The helicase Chl1p is a nuclear protein required for sister-chromatid cohesion, transcriptional silencing, rDNA recombination, ageing and plays an instrumental role in chromatin remodeling. This budding yeast protein is known to preserve genome integrity and spindle length in S-phase. Here we show additional roles of Chl1p at G1/S phase of the cell cycle following DNA damage. Results: G1 arrested cells when exposed to DNA damage are more sensitive and show bud emergence with a faster kinetics in chl1 mutants compared to wild-type cells. This role of Chl1p in G1 phase is Rad9p dependent and independent of Rad24 and Rad53. rad9chl1 shows similar bud emergence as the single mutants chl1 and rad9 whereas rad24chl1 and rad53chl1 shows faster bud emergence compared to the single mutants rad24 , rad53 and chl1 . In case of damage induced by genotoxic agent like hydroxyurea, Chl1p acts as a checkpoint at G1/S. The faster movement of DNA content through G1/S phase and difference in phosphorylation profile of Rad53p in wild type and chl1 cells confirms the checkpoint defect in chl1 mutant cells. Further we have observed that the checkpoint defect is synergistic with the replication checkpoint Sgs1p and functions in prallel to the checkpoint pathway of Rad24p. Conclusion: Chl1p shows Rad53p independent bud emergence and Rad53p dependent checkpoint, confirms its requirement in two different pathways to maintain the G1/S arrest when cells are exposed to damaging agents. The bud emergence kinetics and DNA segregation were similar to wild type when given the same damage in nocodazole treated chl1 cells which establishes the absence of any role of Chl1p at the G2/M phase. The novelty of this paper lies in revealing the versatile role of Chl1p in checkpoints as well as repair towards regulating G1/S transition. Chl1 thus regulates the G1/S phase by affecting the G1 replication checkpoint pathway and shows an additive effect with Rad24p as well as Rad53p activation when damaging agents perturbs the DNA.

EVALUATION OF BREWERS DRIED YEAST PROTEIN IN BROILER DIET

The value of brewers dried yeast protein (BDY) as a replacement of fishmeal in the diet for broiler starters was investigated. In the experiment BDY replaced 0, 25, 50, 75 amd 100% of the fishmeal in the fiet. The average liveweight gain response to increasing levels of BDY at 6 weeks of age was 950.3g, 980.78, 981.8g, 950.5g and 953.2g respec tively. While the figures for the feed/gain ratio were 2.35, 2.28, 2.30, 32 36 and 2.39 respectively. There was no significant differences between these values. Also, the mean feed consumption data for different dietary treatment through the period showed no significant differences. This result suggests that under the conditions of this experiment BDY could replace completely all the fishmeal in the broiler starter diet without any adverse effect on the rate of gain, feed efficiency, or feed consumption of broiler chicks.

Diatomite waste derived N-doped porous carbon for oxygen reduction reaction and supercapacitor

Biomass waste recycling and utilization is of great significance for improving ecological environment and relieving the energy crisis. Waste diatomite adsorbing mass of yeast protein resulted from the beer filtration...