Oil palm and banana root colonization potential of locally isolated nitrogen-fixing and phosphate-solubilizing bacteria

Abstract

Oil palm and banana are the biggest commodity crop and the second largest fruit crop planted in Malaysia. Both oil palm and banana are highly nutrient-demanding crops that requires a large amount of fertilizer input. This presents an opportunity to find alternative source of nutrient that is much cheaper than the imported inorganic fertilizer. Currently, the most feasible alternative to the inorganic fertilizer is the recycling of the organic-rich oil palm empty fruit bunch (EFB) to produce EFB compost as well as the incorporation of nitrogen-fixing bacteria (NFB) and phosphate-solubilising bacteria (PSB) to the EFB compost to increase the supply of nitrogen and phosphorous to the plant at different stages of growth. Hence, the objective of this study was to isolate, screen and identify indigenous bacterium, from the root surroundings of oil palm and banana plant, with highest nitrogen-fixing and phosphate-solubilizing properties. Three NFB and PSB strains (Enterobacter cloaceae KU886016, Burkholderia cepacia KU925862, Serratia marcescens KU925861), were successfully isolated and formulated as biofertilizer for evaluation on oil palm and banana seedlings. Enterobacter cloaceae KU886016 showed higher root colonization ability compared to Burkholderia cepacia KU925862 and Serratia marcescens KU925861, as shown from the FESEM analysis. This finding is important as a direct indication on the suitability of using these bacteria in field application as biofertilizer. Long-Term expectation is for this finding to be able to assist in reducing the dependency on imported inorganic fertilizers, reducing operational cost as well as promoting sustainable soil health.