Biosorption of Metals Ion on Methanol Dehydrogenase Activity Test of Bradyrhizobium japonicum USDA110

Abstract

This research aimed to know effect of absorption metals ion (bisorption) which has different group elements on methanol dehydrogenase (MDH) activity test of a nitrogen fixation bacterium, Bradyhizobium japonicum USDA 110. Ten of metals ion at a concentration of 30 μM were tested to grow B. japonicum USDA 110 in diluted one per ten of nutrient medium. The results of MDH activity test showed that the bacterial growth in medium without added metal ion had similar MDH activity with that of in the medium supplemented with calsium ion/Ca2+. Highest enzymatic activity, 0.08 (U · mg−1), was showed by the bacterium grown in medium supplemented with magnesium/Mg2 + .. MDH was required for the bacterial growth in anerobic condition specially for a root simbiotic bacterium, Bradyhizobium japonicum USDA 110. Addition of magnesium/Mg2+ accelerated the bacterial growth and MDH activity by 2.6 and 1.28 times, respectively. This research results deduced that in an anerobic condition of soil, the metal ions specially calsium and magnesium were required to be added in plant growth medium to accelerate the growth of B. japonicum which well known as bacterial symbiotic on soy bean roots.