Fruit-peel-degrading Potential of Some Legumes-associated Bacteria

Abstract

This research aimed at determining the digestive ability of nine legumes-associated bacteria on the peels of some fruits (orange, watermelon, plantain, banana, pineapple and pawpaw). The bacteria were cultivated separately on each peel for 18 hours at 28oC; the amount of glucose released was quantified using Dinitrosalicylic acid reagent method. The results obtained showed that the bacteria degraded all the peels with the highest (0.297 mg/mL) and lowest (0.087 mg/mL) glucose concentrations produced by Rhizobium leguminosarum FUBO001 and Bonitrorhizobium winogradskyi FUBO004 in banana and pawpaw peels, respectively. The Bo. winogradskyi FUBO004 synthesized 0.101 mg/mL as minimum sugar amount in the former peel while Bradyrhizobium nigeriasis FUBO005 produced the highest glucose quantity (0.167 mg/mL) in the latter peel. The lowest amounts of glucose in orange, watermelon, pineapple and plantain peels produced by Bradyrhizobium nigeriasis FUBO003, Rhizobium nigeriasis, R. nigeriasis and Br. nigeriasis FUBO003 were 0.095, 0.132, 0.09 and 0.248 mg/mL respectively. In these peels, the highest amount of the reducing sugar made was 0.131 mg/mL by Br. nigeriasis FUBO005, 0.211 mg/mL by Br. nigeriasis FUBO005, 0.156 mg/mL by Bo. winogradskyi FUBO004 and 0.291 mg/mL by R. nigeriasis. These results suggest that the bacteria catabolized the fruit peels, reflecting their high potential in the conversion of the fruit peels to useful products.