BIOEXTRACTION OF IRON THROUGH Bacillus sp. SP10 FROM MINERAL OXIDE AND ITS APPLICATION AS PLANT MICRONUTRIENT

Abstract

Iron is an essential micronutrient for all living organisms because of its critical 
 role in metabolic processes. In plants it plays a key role in the synthesis of 
 chlorophyll, some vital enzymatic and metabolic processese. However, most of 
 the iron in nature is present as precipitates or in insoluble forms. Therefore, 
 biological mechanism has been employed to mineralize Fe(III) oxides into 
 Fe(II) through microbial action to increase the availability of soluble iron. An 
 iron reducing bacterial strain was isolated based on its tolerant limits and iron 
 mineralizing ability. The strain Bacillus sp. SP10 effectively mineralized iron 
 in synthetic medium possessing 1% starch and pH 7. In a 25 day’s column 
 study, the soluble Fe(II) as micronutrient showed a gradual increase in each 
 seepage collected from different treatment columns. Similarly, the plants 
 grown on soil obtained from treatment D (i.e. 1% starch + 1% Bacillus sp. 
 SP10 inoculum + 0.25% anthraquinone-2,6-disulphonate) column displayed 
 good growth and maximum shoot length, mainly due to the increased 
 accessibility of iron through microbial mineralization. The mineralization of 
 Fe in soil was established through SEM and EDX analysis.