It has been identified that S-layer protein of Lacticacid bacteria plays a major role in the adhesion function of Lacticacid bacteria.Bacillus subtilis and its spore are beneficial to animal organism,but they stay in intestinal tract shortly.It can make the probiotic of Bacillussubtilis bigger by the display of S-layer protein on the spore of Bacillus subtilisbecause it can prolong the time of Bacillus subtilis in intestinal tract.The styles of the display of heterologous protein on the spore include plasmi...