【摘要】 采用稀释平皿分离测数及琼脂块法研究了微波预处理对土壤放线菌分离效果的影响.结果表明:1)微波处理能显著增加可培养放线菌数量.随着微波处理时间的增加,高有机质土壤放线菌总数呈先增后减的趋势.处理3～15min,GA及HA培养基上放线菌总数分别较对照提高8.3%～92.6%及24.4%～108.5%;处理18～24min,放线菌总数分别较对照降低了62.1%～78.8%及41.4%～79.8%.微波处理对低有机质土壤放线菌数量无明显影响.2)微波处理对可培养放线菌种类有明显影响.随着微波处理时间的增加,高有机质土壤中新出现的放线菌种类呈先增后减趋势.处理3～24min,GA与HA培养基上新出现放线菌种类占放线菌总种类的比例为62.5%～85.7%与66.7%～83.3%,新出现了原小单孢菌属、链轮丝菌属等稀有放线菌属;链霉菌类群也有明显变化.低有机质土壤具有类似趋势.3)微波处理对可培养放线菌中拮抗性放线菌株数占供试放线菌总株数的比例也有明显影响.微波处理6、9和15min,拮抗性放线菌株数所占比例分别较对照提高66.7%、66.7%和83.3%,其中新出现的拮抗性放线菌株数分别占拮抗性放线菌总株数的70.0%,90.0%和81.8%.更多还原

【Abstract】 Dilution plate-and agar block methods were employed to study the effects of microwave irradiation on the isolation of soil actinomycetes.The results showed that:1)Microwave irradiation could significantly increase the total quantity of isolated actinomycetes.With the increasing duration of microwave irradiation,the total quantity of actinomycetes in soils with high organic matter content tended to increase first and decrease then.This quantity on GA and HA culture medium increased by 8.3%-92.6% and 24.4%-108.5% when the irradiation lasted 3-15 minutes,but decreased by 62.1%-78.8% and 41.4%-79.8%,respectively when the irradiation lasted 18-24 minutes,in comparison with that on the control medium.Microwave irradiation showed no remarkable effects on the total quantity of actinomycetes in the soils with low organic matter content.2)Microwave irradiation also exerted remarkable effects on the number of actinomycetes species.With the increase of irradiation duration,the actinomycetes species number in soils with high organic matter content appeared to increase first and decrease then.When the irradiation lasted 3-24 minutes,the newly identified actinomycetes species on GA and HA culture medium,which included rare actinomycete genera such as Promicromonospora and Streptoverticillium,took up 62.5%-85.7% and 66.7%-83.3% of all the actinomycetes species respectively,and the genus Streptmycete also had obvious variation.Soils with low organic matter content showed the similar tendency.3)Microwave irradiation could exert remarkable effects on the percentages of antimicrobial actinomycetes strains to all test actinomycete strains.When the microwave irradiation lasted 6,9,and 15minutes,the percentages of antimicrobial antinomycetes strains on the culture mediums increased by 66.7%,66.7%,and 83.3%,and the newly identified antimicrobial antinomycetes strains made up 70.0%,90.0%,and 81.8% of all the antimicrobial antinomycetes strains,respectively.更多还原