草螺菌Herbaspirillum sp. WT00F的生理生化性质和促生作用研究

Physiochemical properties and growth-promoting effects of Herbaspirillum sp. WT00F

草螺菌(Herbaspirillum)WT00F是本实验室分离获得的一株茶树内生细菌.使用微生物学方法,测试了草螺菌WT00F对22种糖醇类、21种有机酸类和13种氨基酸的碳源利用、8种常见抗生素的敏感性、温度、pH、盐浓度的影响以及33种酶的活性.草螺菌WT00F能利用其中16种糖醇类、17种有机酸类和5种氨基酸作碳源,并能利用14种糖醇类物质产酸.在NaCl浓度≤1%或pH 5.0 8.0的条件下,细菌生长良好,适宜的生长温度为34 37℃.在测试的33种酶中,草螺菌WT00F显示11种酶的活性.草螺菌WT00F对8种常见抗生素敏感,仅对≤5μg/mL浓度的壮观霉素表现抗性.同时,对草螺菌WT00F的促生作用进行了研究.虽然它没有固氮酶活性,但草螺菌WT00F浸泡茶树扦插杆可剌激扦插杆生根和扦插苗新芽生长;喷洒修剪茶树枝后,明显促进修剪枝侧芽生长.无论浸泡还是喷洒,接种过草螺菌WT00F的茶树都生长旺盛,未出现任何植物病症.草螺菌WT00F不仅可用于茶树的扦插繁殖而且可应用于茶园茶树的栽培生产以减少肥料使用和提高茶叶产量,不失为一种有潜力的绿色植物促生剂.

Herbaspirillumsp.WT00 F was an endophytic bacterium isolated fromCamellia sinensis L.Itused 16 glycitols,17 organic acids and 5 amino acids as sole carbon source among 22 glycitols,21 organicacids and 13 amino acids tested,and also utilized 14 glycitols to produce acid.Moreover,this bacteriumdisplayed activities of 11 enzymes in the tested 33 enzymes.The bacterium grew well at pH 5.0—8.0 or whenthe final concentration of NaCl was≤1%.The bacterium was able to grow at wide range of temperature(20—40 ℃) with the optimal temperatures of 34—37 ℃.Herbaspirillumsp.WT00 F was sensitive to all 8 antibioticstested,only showed very weak resistance to spectinomycin(≤5 μg/mL).Although this bacterium did notshow nitrogen-fixing activity,tea cuttings soaked or the pruned tea twigs sprayed with the bacterial culturedemonstrated thatHerbaspirillumsp.WT00 F not only induced the rooting of tea cuttages,but also stimulatedthe growth and development of newborn lateral buds.Whatever soaking or spraying method was applied,teaplats inoculated withHerbaspirillumsp.WT00 F grew vigorously without any disease symptom.Our studiessuggested thatHerbaspirillumsp.WT00 F could be used as a novel green-bioaccelerator for both tea-cuttagepropagation and tea-plant cultivation in tea farms.