On the secondary screening, a loopful of acitnomycete spores on ISP 2 agar medium at 30 oC for 7 days, was inoculated into 100 ml of ISP 2 broth and cultivated on a rotary shaker (200 rpm) at 30 oC for 5 days and then 1 ml of the inoculum was transferred to ISP 2 broth with 0.3 % CaCO3 and cultivated on a rotary shaker (200 rpm) at 30 oC for 14 days.