Earthworms and Cellulase Activity in Agricultural Soils of Nakhon Pathom, Thailand

Earthworms play a vital role in enhancing soil quality and structure in agricultural ecosystems. This study investigated the diversity of earthworm species found in banana and guava orchards in Nakhon Pathom, Thailand, where 166 samples were collected. The results showed that 56.63% of earthworms were in the adult stage. In the banana orchard, researchers identified two families and four species: from the family Megascolecidae, they found Amynthas alexandri, Metaphire posthuma, and Polypheretima elongata, along with one species from the family Moniligastridae, Drawida sp. In the guava orchard, two families and two species were identified: from the family Megascolecidae, Metaphire posthuma, and from the family Moniligastridae, Drawida sp. Fungi isolated from the intestines of earthworms, precisely the strains EW2, EW3, EW6, EW13, EW16, EW23, EW25, EW26, EW28, EW38, EW39, EW40, EW41, EW43, and EW44, have demonstrated the ability to produce cellulase. Among these, the fungus EW41 exhibited the highest cellulase activity, measuring 32.97 units per milliliter at an optimal temperature of 60 ℃ and a pH of 5.0. This study highlights that most earthworm species in agricultural soils belong to the family Megascolecidae. Furthermore, earthworms play a crucial role in enhancing the chemical properties of the soil. The cellulolytic fungi present in earthworm intestines contribute to the natural decomposition of organic matter, thereby promoting soil health by converting plant residues into nutrient-rich compost. These findings suggest promising applications of earthworm-associated fungi in sustainable agriculture and organic waste management.