The Influence of Addition on the Aroma Profile of a Kombucha Tea Fermentation.

Traditional kombucha is a functional tea-based drink that has gained attention as a low or non-alcoholic beverage. The fermentation is conducted by a community of different microorganisms, collectively called SCOBY (Symbiotic Culture of Bacteria and Yeast) and typically consists of different acetic acid bacteria and fermenting yeast, and in some cases lactic acid bacteria that would convert the sugars into organic acids-mostly acetic acid. In this study, the effect of including a starter culture in a kombucha fermentation was investigated.

Tradition as a Stepping Stone for a Microbial Defined Water Kefir Fermentation Process: Insights in Cell Growth, Bioflavoring, and Sensory Perception.

A process development from a traditional grain-based fermentation to a defined water kefir fermentation using a co-culture of one lactic acid bacterium and one yeast was elaborated as a prerequisite for an industrially scalable, controllable, and reproducible process. Further, to meet a healthy lifestyle, a low ethanol-containing product was aimed for. Five microbial strains-, , , , and -were used in pairs in order to examine their influence on the fermentation progress and the properties of the resulting water kefir products against grains as a control.

Zinc availability from zinc-enriched yeast studied with an in vitro digestion/Caco-2 cell culture model.

Background: Organic zinc sources for the treatment of zinc deficiency or as a supplement to a specific diet are increasingly needed. Zinc-enriched yeast (ZnYeast) biomass is a promising nutritional supplement for this essential micronutrient. However, these products are not yet authorized in the European Union and a clear position from the European Food Safety Authority on the use of ZnYeast as a zinc supplement is pending, demanding more data on its bioavailability.

Microbial production of glutathione.

Glutathione (GSH) is a non-coding tripeptide thiol with several important regulative and protective functions in eukaryotes and in most prokaryotes. The primary function of GSH is to maintain the redox potential of the cell, which is directly connected to GSH concentration, and to prevent cellular damages caused by reactive oxygen species or toxic heavy metals. Due to its antioxidant character, it is widely used in pharmaceutical, cosmetic and food industry.

Systematic development of a two-stage fed-batch process for lipid accumulation in Rhodotorula glutinis.

The application of oleaginous yeast cells as feed supplement, for instance in aqua culture, can be a meaningful alternative for fish meal and oil additives. Therefore, a two-stage fed-batch process split into growth and lipogenesis phase was systematically developed to enrich the oleaginous yeast Rhodotorula glutinis Rh-00301 with high amounts of lipids at industrial relevant biomasses. Thereby, the different carbon sources glucose, sucrose and glycerol were investigated concerning their abilities to serve as a suited raw material for growth and/or lipid accumulation.

Medium optimization based on yeast's elemental composition for glutathione production in Saccharomyces cerevisiae.

The production of glutathione (GSH) or GSH enriched yeast is still in the focus of research driven by a high industrial interest. In this study, an optimal growth rate for GSH production via Saccharomyces cerevisiae Sa-07346 was investigated. To further improve the fermentation process in a way that it is independent of lots, the influence of different WMIX medium compositions on biomass and GSH production was studied.

Evaluation of cysteine ethyl ester as efficient inducer for glutathione overproduction in Saccharomyces spp.

Economical yeast based glutathione (GSH) production is a process that is influenced by several factors like raw material and production costs, biomass production and efficient biotransformation of adequate precursors into the final product GSH. Nowadays the usage of cysteine for the microbial conversion into GSH is industrial state of practice. In the following study, the potential of different inducers to increase the GSH content was evaluated by means of design of experiments methodology.

Enhanced incorporation yield of cysteine for glutathione overproduction by fed-batch fermentation of Saccharomyces cerevisiae.

In the following work a high cell density fed-batch process with Saccharomyces cerevisiae coupled with a high efficient incorporation of cysteine for glutathione (GSH) overproduction was developed. Therefore, a feeding strategy based on the respiratory quotient (RQ) was applied to ensure high biomass (96.1g/l).

Control of cell morphology of probiotic Lactobacillus acidophilus for enhanced cell stability during industrial processing.

The viability of bacteria during industrial processing is an essential quality criterion for bacterial preparations, such as probiotics and starter cultures. Therefore, producing stable microbial cultures during proliferation is of great interest. A strong correlation between the culture medium and cellular morphology was observed for the lactic acid bacterium Lactobacillus acidophilus NCFM, which is commonly used in the dairy industry as a probiotic supplement and as a starter culture.