The present invention relates to transglutaminases and transglutaminase preparations obtained from lower fungi belonging to the class Oomycetes. Unprecedented high-level expression is achievable by growing these coenocytium forming organisms, especially the strains Pythium sp., Pythium irregulare, Pythium dissotocum, Pythium periilum (or P. periplocum), Pythium torulosum, Pythium ultimum, Pythium aphanidermatum, Phytophthora cactorum, Phytophthora palmivora, Phytophthora porri, Phytophthora infestans, Phytoph-thora megasperma, Phytophthora cinnamomi and Phytophthora cryptogea. Arecombinant transglutaminase has been cloned and expressed, the enzyme and enzyme preparations being useful for cross-linking proteins, e.g. in flour, baked products, meat products, fish products, cosmetics, cheese, milk products, gelled food products and leather finishing, or as a glutaminase, e.g. in bread and other baked glutein-containing food products.