Coupling engineering of Saccharomyces cerevisiae with medium optimization for the production of ergothioneine

Ergothioneine (ERG) is a naturally occurring, exogenous antioxidant that is nonetheless abundant in the human body. It has been shown both to reduce oxidative damage and to be involved in several diseases in vivo1,2. Therefore, ergothioneine is poised to take a place in the dietary supplement industry. Here we describe the engineering of the yeast Saccharomyces cerevisiae and subsequent medium optimization to produce ergothioneine by fermentation. After integrating combinations of biosynthetic pathways from different organisms, we screened yeast strains for their production of ERG. Next, the highest producing strain was engineered with ergothioneine transporters, and its amino acid metabolism was altered by knock-out of Tor1 or Yih1. The bottleneck for ergothioneine production was determined by integration of a second copy of the pathway enzymes. We also optimized the media composition for production of ergothioneine using yeast S. cerevisiae. Following these manipulations, we obtained a titer of 630 mg/l in fed-batch cultivation in bioreactors. This work shows that with further engineering of the strain, current chemical synthesis of ergothioneine could be replaced with a sustainable alternative. 1. Cheah, I. K. & Halliwell, B. Ergothioneine; antioxidant potential, physiological function and role in disease. Biochim. Biophys. Acta - Mol. Basis Dis. 1822, 784–793 (2012). 2. Halliwell, B., Cheah, I. K. & Tang, R. M. Y. Ergothioneine - a diet-derived antioxidant with therapeutic potential. FEBS Lett. (2018). doi:10.1002/1873-3468.1312

A Role of a Newly Identified Isomerase From Yarrowia lipolytica in Erythritol Catabolism

Erythritol is a natural sweetener produced by microorganisms as an osmoprotectant. It belongs to the group of polyols and it can be utilized by the oleaginous yeast Yarrowia lipolytica. Despite the recent identification of the transcription factor of erythritol utilization (EUF1), the metabolic pathway of erythritol catabolism remains unknown. In this study we identified a new gene, YALI0F01628g, involved in erythritol assimilation. In silico analysis showed that YALI0F01628g is a putative isomerase and it is localized in the same region as EUF1. qRT-PCR analysis of Y. lipolytica showed a significant increase in YALI0F01628g expression during growth on erythritol and after overexpression of EUF1. Moreover, the deletion strain ΔF01628 showed significantly impaired erythritol assimilation, whereas synthesis of erythritol remained unchanged. The results showed that YALI0F1628g is involved in erythritol assimilation; thus we named the gene EYI1. Moreover, we suggest the metabolic pathway of erythritol assimilation in yeast Y. lipolytica

Assessment of the genetic structure of Central European cattle breeds based on functional gene polymorphism

As many European cattle breeds are considered to be threatened with extinction, and existing genetic variability is increasingly at risk of being irretrievably lost, its assessment is crucial. The aim of the study was to assess the genetic variability of seven breeds of cattle in Central Europe on the basis of polymorphism at the loci of functional genes, encoding β-lactoglobulin (LGB), leptin (LEP), prolactin (PRL), oestrogen receptor alpha (ERα) and growth hormone receptor (GHR). The research was carried out on 290 individuals – 50 Polish White-backed (PW), 50 Lithuanian White-backed (LWB), 50 Polish Red (PR), 50 Lithuanian Red (LR), 22 Carpathian Brown (CB), 18 Ukrainian Grey (UG) and 50 Slovak Pinzgauer (PG). Gene polymorphism was determined by PCR-RFLP. The statistical indicators estimated, i.e. the frequency of alleles and genotypes, observed and expected heterozygosity (HO and HE), F-statistics, gene flow (Nm), and genetic distances, were used to characterize the genetic structure of these cattle breeds. The research demonstrated that the populations analysed have undergone a bottleneck process as a consequence of the rapid decline in the size of individual populations. Owing to the introduction of genetic resources conservation programmes, endangered populations can slowly be restored to a state of genetic balance. Keywords: Genetic variability, Functional genes, Central European cattle breeds, Gene polymorphism, Population genetic structur

Polymorphism of the Melanocortin 1 Receptor ( MC1R) Gene and its Role in Determining the Coat Colour of Central European Cattle Breeds

There are many genes responsible for the appearance of different coat colours, among which the melanocortin 1 receptor gene (MC1R) plays an important role. The aim of the study was to characterize genetic variation in Central European cattle breeds based on polymorphism of the MC1R gene and factors determining their coat colour. The study was conducted on 290 individuals of the following breeds: Polish White-Backed (PW), Lithuanian White-Backed (LW), Polish Red (PR), Lithuanian Red (LR), Carpathian Brown (CB), Ukrainian Grey (UG), and Slovak Pinzgau (SP). Polymorphism at the MC1R gene locus was analysed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) using two restriction enzymes: Cfr10I and SsiI. The proportions of alleles and genotypes in the MC1R locus indicates a strong relationship between polymorphism and the coat colour of cattle: The ED allele proved to be characteristic for the breeds with a white-backed coat (PW and LW), while the dominant allele in the red breeds (PR and LR) was E+. It is noteworthy that coat colour in the SP population was determined only by the recessive e allele, which resulted in the formation of a separate clade in the phylogenetic tree

Data_Sheet_1_A Role of a Newly Identified Isomerase From Yarrowia lipolytica in Erythritol Catabolism.docx

<p>Erythritol is a natural sweetener produced by microorganisms as an osmoprotectant. It belongs to the group of polyols and it can be utilized by the oleaginous yeast Yarrowia lipolytica. Despite the recent identification of the transcription factor of erythritol utilization (EUF1), the metabolic pathway of erythritol catabolism remains unknown. In this study we identified a new gene, YALI0F01628g, involved in erythritol assimilation. In silico analysis showed that YALI0F01628g is a putative isomerase and it is localized in the same region as EUF1. qRT-PCR analysis of Y. lipolytica showed a significant increase in YALI0F01628g expression during growth on erythritol and after overexpression of EUF1. Moreover, the deletion strain ΔF01628 showed significantly impaired erythritol assimilation, whereas synthesis of erythritol remained unchanged. The results showed that YALI0F1628g is involved in erythritol assimilation; thus we named the gene EYI1. Moreover, we suggest the metabolic pathway of erythritol assimilation in yeast Y. lipolytica.</p