Editorial: On the Special Issue "Yeast Science in Central and Eastern Europe".

The first Polish Yeast Conference was held at the University of Rzeszow in South‐Eastern Poland. Investigators from all the major Polish cities, Warsaw, Wroclaw, Poznan, Cracow, Gdansk, Lodz, Lublin, and Rzeszow, were joined by international colleagues from the United States, Japan, Sweden, Belgium, France, United Kingdom, Slovakia, and Ukraine in eight scientific sessions. The 114 attendees presented lectures and posters covering a wide variety of current topics leading to a very stimulating and successful conference. The conference demonstrated the presence and great potential for further development of yeast research in Poland. Dr. Gianni Liti, Editor‐in‐Chief of the Journal Yeast generously provided the conference's participants the opportunity of contributing peer‐reviewed articles to the Yeast Special Issue “Yeast Science in Central and Eastern Europe”. The 13 manuscripts, most from Poland, covered many of the topics presented during the conference. P. Fickers (Belgium) and his Chinese colleagues described improved production of the sweetener, erythritol, in Yarrowia lipolytica emanating from activation of the alternative glycerol catabolic, known as dihydroxyacetone, pathway. Overexpression of DAK2 coding for dihydroxyacetone kinase together with genes TKL1 and TAL1 coding for transketolase and transaldolase, respectively, led to a strain with increased productivity and yield of erythritol in glycerol medium. The paper of T. Cooper and co‐authors from the United States described the mechanisms through which nitrogen catabolite repression‐sensitive transcription activator Gln3 and TorC1 kinase regulate and integrate transcriptional control of the GABA (g‐aminobutyric acid) shunt and retrograde pathway genes. TorC1 regulates the last three shunt genes in a Gln3‐dependent manner, whereas it does so in a Gln3‐independent manner for the first shunt GABA decarboxylase gene. GABA shunt and retrograde pathway gene expression increase in the presence of nickel, likely to cope with increased ROS that nickel detoxification generates. H. Takagi and colleagues from Japan showed that arginine permease, Can1, beyond being an arginine transporter, also acts as an arginine transceptor that participates in the inhibition of proline utilization. They also reported that arginine activates protein kinase A signaling via the Can1 permease. The review of A. Tyczewska and K. Grzywacz from Poznan (Poland), assembled data showing that tRNA fragments are responsible for numerous regulatory functions in yeast. While the regulatory role of microRNAs and small interfering RNAs has been known for many years, recent studies demonstrated that specific tRNA fragments (tRFs) also affect gene expression in pathogenic and non‐pathogenic yeasts. D. Satala et al. from Cracow (Poland) described interactions between Candida parapsilosis adhesins, a family of the agglutinin‐like sequence protein, and human cells. These interactions were shown to be enhanced in the presence of fibronectin and vitronectin. Their findings further characterize the mechanisms of host‐pathogen interactions in infections caused by C. parapsilosis. A. Sibirny et al. from Ukraine and Rzeszow (Poland), reported that disruption of the ACG1 gene, encoding β‐1,6‐N‐ acetylglucosaminyltransferase affects autophagic degradation of the model recombinant protein β‐galactosidase and the native cytosolic proteins formaldehyde and formate dehydrogenases in the methylotrophic yeast Komagatella phaffii. This organism is an effective producer of industrially important recombinant proteins. V. Passoth et al. from Sweden briefly reviewed the production of biochemicals from lignocellulose by oleaginous yeasts, including established methods for the production and rapid quantification of yeast lipids. They also presented recent advances in the research of oleaginous yeasts, their physiology on various carbon sources, the application of yeast lipids as feed, and the production of potential non‐lipid products. A. Sibirny and colleagues in Ukraine and Rzeszow (Poland) reported the construction of a Candida famata strain that overproduces and excretes large amount of flavin mononucleotide (FMN). This was accomplished by overexpressing the FMN biosynthetic pathway structural, exporter, and regulatory genes. By additionally expressing the SEF1 transcription activator under the lactose‐ induced LAC4 promoter, the strain is able to use much more economical cheese whey rather than glucose as its carbon source. In the review paper, M. Rapala‐Kozik and her coworkers (Cracow, Poland) described the role of C. albicans in the formation of polymicrobial biofilms in the oral cavity paying attention on multispecies microbial interactions in C. albicans formed biofilms involving cooperation, competition, or antagonism, that lead to an increase in the propagation of oral infection. In the research paper, M. Rapala‐Kozik's laboratory identified two neutrophil populations that release neutrophil extracellular traps (NETs) associated with phagocytosis when in contact with C. albicans blastospores. The first population exhibited increased ability to release NETs without internalization of the pathogen, whereas increased NET production in the second population was inherently associated with phagocytosis leading to the conclusion that