B1 and B2 didn t secrete polysaccharose on beef polypeptone agar medium(BPA) and the nematode didn t grow on BPA medium with B1 and B2,while B1 and B2 secreted polysaccharose on PSA medium.

• 用牛肉膏蛋白胨细菌培养基培养B1和B2两种细菌时,细菌无多糖产生,线虫不能取食细菌而生长繁殖;当用马铃薯蔗糖真菌培养基培养B1和B2两种细菌时,细菌分泌丰富的多糖,线虫生长繁殖较好。