Wood is the main renewable material and it is largely used as building material and in paper- pulp manufacturing. The enzymes involved in the degradation of lignocellulosic material are cellulases, hemicellulases and carbohydrate esterases. The carbohydrate esterases involved in the degradation of the lignocellulosic materials are feruloyl esterases [E.C. 3.1.1.73; also known as ferulic acid esterases (FAE), cinnamoyl esterases, cinnamic acid hydrolases]. They catalize the cleavage and the formation of ester bonds between plant cell wall polysaccharide and phenolic acids present in the plant cell walls. The objective of the study was the isolation and purification of microorganisms producing esterases, the selection of carbohydrate esterases producers in order to obtain the enzymes involved in the degradation of lignocellulosic materials. Choosing the most suitable substrate for the feruloil esterases synthesis, in general, it is an important factor for obtaining a satisfactory yield of enzymes derived from streptomycetes. The substrate serves not only as a source of carbon and energy, but provides the catabolic induction compounds that microorganisms need for adaptation to the environment and for their survival. In this research 97 strains of Streptomyces spp. from Romania soil samples were isolated. Preliminary qualitative screening assays for the enzyme production were carried out in Petri dishes. The producer of extracellular esterase was studied by cultivation in liquid basal medium supplemented with 2% wheat bran as a sole carbon source, at 26˚C, 150 rpm, on an orbital shaker. Samples were taken periodically from the culture fluid at intervals of 18 h - 24 h for 7 days, and the esterase activity and the content of extracellular protein were determined by spectrophotometric methods. The content of extracellular protein was determined at the point of maximum catalytic activity. Of all the strains cultured and tested, only five strains were found to have a good potential for esterase activity