The mannanase, cellulase and xylanase-producing thermophilic bacteria, designated EJ3, was isolated from fresh spent mushroom (Pleurotus eryngii) substrates taken from the DOJUN farm located in Keyongnam, Korea. The isolate EJ3 was facultatively anaerobic and grew at temperature ranging from 20℃ to 60℃ with an optimal temperature of 37℃. The DNA G+C content of the isolate EJ3 was 45 mlo%. The major fatty acids were anteiso-15:0 (38.9%), 17:0 (7.4%), and iso-15:0 (38.2%). The 16S rRNA gene sequence similarity between the isolate EJ3 and other Bacillus strains varied from 97% to 99%. In the phylogenetic analysis based on these sequences, the isolate EJ3 and Bacillus subtilis clustered within a group and separated from other species of Bacillus. Based on the physiological and molecular properties, the isolate EJ3 was classified within the genus Bacillus as Bacillus subtilis EJ3. The optimal growth condition of B. subtilis EJ3 were pH 6.0 and 55℃, respectively.

This study was conducted to evaluate the feeding value of the spent mushroom (Pleurotus eryngii) substrates (SMS) in laying hens (Hy-Line Brown). The fresh spent mushroom (Pleurotus eryngii) substrates collected from the DOJUN farm were fermented with Bacillus subtilis EJ3 for 2 weeks. A total of twenty-four laying hens were fed corn-soy based experimental diets containing 0% (control), 5% (T1), 10% (T2) and 15%(T3) fermented SMS for 7 weeks. There were no significant differences among the treatments in egg production, egg weight, egg mass, feed conversion and viability during the experimental period. Feed intake was significantly lowered in control (118.3 g) than T1 (121.9 g), T2 (120.3 g) and T3 (122.4 g). There were no significant differences among the treatments eggshell breaking strength, thickness and haugh unit, whereas the yolk color of T1, T2 and T3 were significantly heavy than T0. The palatability of boiled meat was significantly better in the T3 laying hens than in the T0 laying hens. In conclusion, fermented SMS can be used as resource of feed in laying hen feed at 5.0-15% level without effect on performance and egg qualify.