Since 1995, Kondratyuk has been working for many years with Professor Ingvar Kärnefelt from the Botanical Museum of Lund University (Sweden) to study lichens of the family Teloschistaceae. Many new genera have been circumscribed as a result, including Xanthomendoza, Josefpoeltia, Oxneria, and Rusavskia. Extensive collaborations with South Korean scientists have also resulted in the description of many taxa previously unknown to science. As of 2019, Kondratyuk has been the author or co-author of more than 400 scientific publications. Some well-known publications include "Flora of lichens of Ukraine. Volume 2. Issue 2." (1993), "The second Checklist of Lichen forming, Lichenicolous and Allied fungi of Ukraine" (1998), "A Catalog of the Eastern Carpathian Lichens" (2003), "Checklist of Lichens of the Western Carpathians" (2004), " Determinant of lichens of Russia. Issue 9" (2004), "Lichen-Forming, Lichenicolous and Allied Fungi of Israel"(2005), "Lichenoindication (Manual)" (2006), "Indication of the state of the environment of Ukraine with the help of lichens" (2008).
