Abstract

• One of the insect associated bacterium, Streptomyces sp. SirexAA-E (SirexAA-E), was described to be highly cellulolytic. SirexAA-E grew well on cellulose and other plant cell wall materials such as xylan, and secretes a suite of specialized enzymes depending on the available carbon sources in the growth medium. Non-crystalline cellulose (CMC) and chemically pretreated miscanthus were used as sole carbon sources, and secreted enzymes were compared between two culture conditions. In the presence of CMC, several prominent cellulaseswere determined by SDS-PAGE. While in the presence of miscanthus, dozens of enzymes including above cellulases were determined, thus I decided to use miscanthus as a sole carbon sources to prepare the culture supernatant of Sirex AAE. The optimum condition of cultivation of SirexAA-E on miscanthus was determined with regard to protein yield (mg/L) and quality. It was confirmed that 5 days with 1 mL inoculum into 50 mL culture gave the highest protein yields with intact form of secreted proteins.