Rahman Atiqur, Sitepu Irnayuli R, Tang Sui-Yan, Hashidoko Yasuyuki
Division of Applied Bioscience, Research Faculty of Agriculture, Hokkaido University, Sapporo, Japan.
Biosci Biotechnol Biochem. 2010;74(11):2202-8. doi: 10.1271/bbb.100360. Epub 2010 Nov 7.
Rhizobacteria isolated from wild dipterocarp saplings in Central Kalimantan, Indonesia, were subjected to Salkowski's reagent test, which is often used in detecting indolic substances. Among 69 isolates grown in a low-nitrogen medium supplemented with L-tryptophan (TRP), culture fluids of 29 strains were positive to the test, in which 17 bacteria turned red and other 10 pink. All the red type rhizobacteria actively converted TRP into tryptophol (TOL), while some yielded indole-3-acetic acid (IAA) with TOL production. They also showed a capacity to decompose gallotannin into pyrogallol via gallic acid. On the other hand, an active IAA-producing Serratia sp. CK67, and three Fe-solubilizing Burkholderia spp. CK28, CK43, and Citrobacter sp. CK42, were all involved in pink type rhizobacteria, which were more effective, oxidative TRP-degraders than the red type rhizobacteria. Thus, Salkowski's reagent test should be a useful primary index in the screening of functional rhizobacteria in peatland ecosystem.
从印度尼西亚加里曼丹中部野生龙脑香树苗中分离出的根际细菌,接受了常用于检测吲哚类物质的索尔科夫斯基试剂测试。在69株于添加了L-色氨酸(TRP)的低氮培养基中生长的分离菌株中,29株菌株的培养液测试呈阳性,其中17株细菌变红,另外10株变粉。所有红色型根际细菌都能将TRP积极转化为色醇(TOL),而一些细菌在产生TOL的同时还能产生吲哚-3-乙酸(IAA)。它们还表现出将五倍子单宁通过没食子酸分解为焦性没食子酸的能力。另一方面,一株活跃产IAA的沙雷氏菌属菌株CK67,以及三株解铁的伯克霍尔德菌属菌株CK28、CK43和柠檬酸杆菌属菌株CK42,均属于粉色型根际细菌,它们是比红色型根际细菌更有效的氧化TRP降解菌。因此,索尔科夫斯基试剂测试应是泥炭地生态系统中功能性根际细菌筛选的一个有用的主要指标。