Evaluation of Nitrogen-Fixing Bacteria in Southeast Asia

1)泰国研究人员从泰国酸性土壤中的大豆根瘤中分离出各种根瘤菌。这些菌株在pH 3.5或4.0下生长。通过与大坂大学的合作，三个耐酸性慢生根瘤菌菌株成功地转化为用绿色荧光蛋白（GFP）标记。这些菌落在紫外线照射下显示绿色荧光。2）印度尼西亚研究人员从印度尼西亚豆科树木的根瘤中分离出固氮根瘤菌。这些细菌是与大坂大学、广岛大学和鹿儿岛大学合作分类的。从印度尼西亚不同地点的马占相思根瘤中分离的细菌菌株被分类为慢生根瘤菌。从印度尼西亚不同地点的假马齿苋根瘤中分离的细菌菌株被分类为Bradyrhizobiwn elkanil，Rizizobiwn tropici和这些物种之间的菌株。对一株耐酸根瘤菌BTCC-B64作为氮肥替代品进行了评价。3）以菲律宾分离的固氮菌固氮菌（Azotobacter sp.）和纤维素分解真菌木霉（Trichoderma sp.）为接种物，接种牛粪-稻壳船体堆肥。接种固氮菌可提高物料的降解率和养分含量，并提高堆肥中的接种量。4）马来西亚研究人员从固氮革兰氏阳性菌Paenibacillus azotofixans中克隆并鉴定了niflHDKTY Peron。固氮菌对香蕉和油棕幼苗是一种有效的生物强化剂，对植物性大豆是一种有效的生物强化剂，对香蕉也是一种生物肥料。

1)Thai researchers isolated various kinds of rhizobia from nodules of soy bean in acidic soils in Thailand. These strains grow at pH 3.5 or at 4.0. By collaboration with Osaka University, three acid tolerant strains of Bradyrhizobium were succeeded in transformation to tagging with the Green Fluorescence Protein (GFP). These colonies on the plates showed green fluorescence under the UV exposure.2)Indonesian researchers isolated nitrogen-fixing rhizobia from nodules of leguminous trees in Indonesia. These bacteria were classified by collaboration with Osaka University, Hiroshima University, and Kagoshima University. Bacterial strains isolated from root nodules on Acacia mangium at various locations in Indonesia were classified to Bradyrhizobium elkanji. Bacterial strains isolated from root nodules on Paraserianthes falcataria at various locations in Indonesia were classified into Bradyrhizobiwn elkanil, Rizizobiwn tropici and strains between these species. An acid tolerant strain, Bradyrhizobiwn sp. BTCC-B64 was evaluated as nitrogen fertilizer substitute. The infection of the strains were effective on the nitrogen fixation which performed by the total dried weight of plants, roots and nodules.3)Free living nitrogen-fixing bacteria, Azotobacter sp. or cellulolytic fungi of Trichoderma sp. isolated in Philippines were used as inoculant in cattle manure-rice hull compost. The inoculation with nitrogen-fixing bacteria improved the degradation and nutrient content of the materials and enhance the inoculant load in the compost.4)The niflHDKTY Peron from a nitrogen fixing gram positive bacterium, Paenibacillus azotofixans were cloned and characterized by Malaysian researchers. Azospirillun was found to be an effective bioenhancer for banana and oil palm seedings, and vegetatable soybean as well as a biofertilizer for banana.5)Survivability of the inoculant of Bradyrhizobium japonicum in acid paddy soil in Vietnam was investigated.