关键词: 土壤芽孢杆菌, 解磷, 解钾, 成都市郊区

Abstract: 27 soil samples were collected at 0~20 cm depth in Chengdu suburbs.With dilution plate method,soil suspensions with heat treatment at 80℃ for 10 min were spread onto beef extract peptone malt extract agar to enumerate Bacillus spp.The potential of 333 isolates on phosphorus-releasing and potassium-releasing were evaluated on different media containing non-soluble mineral phosphorus,organic phosphorus and potassium,respectively.The results showed that Bacillus species possessed great potential of dissolving mineral phosphorus in Chengdu suburbs soil.About 15 percent of 333 isolates displayed the potential.Based on the characteristics of morphology and physiology-biochemistry,these isolates were identified as 15 Bacillus species.B. licheniformis,B. megaterium and B. pumilus belonged to the predominant species.Three isolates were selected for their farther study.Most of 333 isolates grow slowly on media containing non-soluble organic phosphorus and potassium,but their ability of dissolving organic P and K was low.

Key words: soil Bacillus spp., phosphorus-releasing, potassium-releasing, Chengdu suburbs