High-Resolution Melting Analysis Potential for var. Authentication in Probiotic-Enriched Food Matrices.

To date, the only probiotic yeast with evidence of health-promoting effects is var. . The expanded market including dietary supplements and functional foods supplemented with var.

Acetic and citric acids effect the type II secretion system and decrease the metabolic activities of salmon spoilage-related Rahnella aquatilis KM05.

Rahnella aquatilis causes seafoods to spoil by metabolizing sulfur-containing amino acids and/or proteins, producing HS in products. The type II secretion system (T2SS) regulates the transport of proteases from the cytoplasm to the surrounding environment and promotes bacterial growth at low temperatures. To prevent premature fish spoilage, new solutions for inhibiting the T2SS of bacteria should be researched.

Multiple region high resolution melting-based method for accurate differentiation of food-derived yeasts at species level resolution.

Yeasts comprise a divergent group of microorganisms playing an important role in foods production. To monitor the production processes, validate authenticity and safety of foods, reliable methods of yeast identification and differentiation are needed. Nowadays, traditional PCR/sequencing-based methods are replaced by rapid techniques not requiring post-PCR processing.

A new set of reference genes for comparative gene expression analyses in Yarrowia lipolytica.

Accurate quantitation of gene expression levels require sensitive, precise and reproducible measurements of specific transcripts. Normalization to a reference gene is the most common practice to minimize the impact of the uncontrolled variation. The fundamental prerequisite for an accurate reference gene is to be stably expressed amongst all the samples included in the analysis.

Production of Raw Starch-Digesting Amylolytic Preparation in and Its Application in Biotechnological Synthesis of Lactic Acid and Ethanol.

Sustainable economy drives increasing demand for raw biomass-decomposing enzymes. Microbial expression platforms exploited as cellular factories of such biocatalysts meet requirements of large-volume production. Previously, we developed recombinant strains able to grow on raw starch of different plant origin.

Optimization of Yarrowia lipolytica-based consolidated biocatalyst through synthetic biology approach: transcription units and signal peptides shuffling.

Nowadays considerable effort is being pursued towards development of consolidated microbial biocatalysts that will be able to utilize complex, non-pretreated substrates and produce valuable compounds. In such engineered microbes, synthesis of extracellular hydrolases may be fine-tuned by different approaches, like strength of promoter, type of secretory tag, and gene copy number. In this study, we investigated if organization of a multi-element expression cassette impacts the resultant Yarrowia lipolytica transformants' phenotype, presuming that different variants of the cassette are composed of the same regulatory elements and encode the same mature proteins.

Feeding strategy impacts heterologous protein production in Yarrowia lipolytica fed-batch cultures-Insight into the role of osmolarity.

Fed-batch cultivation is the preferred bioprocessing strategy applied in microbial production of proteins. Feeding strategy is crucial parameters to be optimized upon development of a fed-batch process. In this study, we investigated impact of different feeding strategies on production of recombinant enzymatic protein in Yarrowia lipolytica cultures.

Rapid micro-assays for amylolytic activities determination: customization and validation of the tests.

High-throughput function-based screening techniques remain the major bottleneck in the novel biocatalysts development pipeline. In the present study, we customized protocols for amylolytic activity determination (Somogyi-Nelson and starch-iodine tests) to micro-volume thermalcycler-based assays (linearity range 60-600 μM of reducing sugar, R = 0.9855; 0-2 mg/mL of starch, R = 0.

Genetic engineering of Ehrlich pathway modulates production of higher alcohols in engineered Yarrowia lipolytica.

Microbial cells can produce a vast spectrum of chemical compounds, including those most desired by the global chemical market, for example, higher alcohols, which are promising alternative fuels and chemical feedstock. In the current research, we investigated the effects of the Ehrlich pathway genetic engineering on higher alcohols production in Yarrowialipolytica, which directly follows our previous findings concerning elucidation of putative molecular identities involved in this pathway. To this end, we constructed two alternative expression cassettes composed of previously identified genes, putatively involved in the Ehrlich pathway in Y.

Robust signal peptides for protein secretion in Yarrowia lipolytica: identification and characterization of novel secretory tags.

Upon expression of a given protein in an expression host, its secretion into the culture medium or cell-surface display is frequently advantageous in both research and industrial contexts. Hence, engineering strategies targeting folding, trafficking, and secretion of the proteins gain considerable interest. Yarrowia lipolytica has emerged as an efficient protein expression platform, repeatedly proved to be a competitive secretor of proteins.

and are Highly Efficient Microbial Cell Factories of Natural Amino Acid-Derived Aroma Compounds.

The pivotal role of non-conventional yeast (NCY) species in formation of valuable aroma compounds in various food commodities is widely acknowledged. This fact inspires endeavors aiming at exploitation of food-derived NCYs as biocatalysts in natural aromas production. In this study, we isolated, characterized and evaluated aroma-producing capacity of two NCY representatives- 7.

Evaluation of heterologous α-amylase production in two expression platforms dedicated for Yarrowia lipolytica: commercial Po1g-pYLSC (php4d) and custom-made A18-pYLTEF (pTEF).

In view of the constantly increasing demand for cost-effective, low-energy and environmentally friendly industrial processes and household care products, enzyme production occupies an essential place in the field of biotechnology. Along with increasing demand for industrial and household care enzymes, the demand for heterologous expression platforms has also increased. Apart from the conventional hosts, e.

Evaluation of a recombinant insect-derived amylase performance in simultaneous saccharification and fermentation process with industrial yeasts.

Starch is the dominant feedstock consumed for the bioethanol production, accounting for 60 % of its global production. Considering the significant contribution of bioethanol to the global fuel market, any improvement in its major operating technologies is economically very attractive. It was estimated that up to 40 % of the final ethanol unit price is derived from the energy input required for the substrate pre-treatment.

Cloning, expression, and purification of insect (Sitophilus oryzae) alpha-amylase, able to digest granular starch, in Yarrowia lipolytica host.

Raw-starch-digesting enzymes (RSDE) are of major importance for industrial applications, as their usage greatly simplifies the starch processing pipeline. To date, only microbial RSDE have gained considerable attention, since only microbial production of enzymes meets industrial demands. In this study, α-amylase from rice weevil (Sitophilus oryzae), the major rice pest, was cloned and expressed in Yarrowia lipolytica Po1g strain.

SpaCBA sequence instability and its relationship to the adhesion efficiency of Lactobacillus casei group isolates to Caco-2 cells.

The ability to adhere to enterocytes is one of the key features of probiotics. This process involves a number of factors, among which the important role of pili was demonstrated. Some Lactobacillus species are confirmed to have heterotrimeric spaCBA type pili.

Evaluation of quantitative PCR measurement of bacterial colonization of epithelial cells.

Microbial colonization is an important step in establishing pathogenic or probiotic relations to host cells and in biofilm formation on industrial or medical devices. The aim of this work was to verify the applicability of quantitative PCR (Real-Time PCR) to measure bacterial colonization of epithelial cells. Salmonella enterica and Caco-2 intestinal epithelial cell line was used as a model.