Skrining Aktinomisetes Selulolitik Asal Rizosfer Dehaasia pugerensis Koord. & Valeton di Kawasan Bandealit

Abstract

The bioconservation of Dehaasia pugerensis, a rare and endemic plant, can be supported through preliminary exploration of the potential of actinomycete isolates derived from the rhizosphere of D. pugerensis. Cellulolytic actinomycetes play a role in litter decomposition through the production of cellulase enzymes, thereby potentially increasing the availability of nutrients, particularly organic carbon, in the soil. This study aims to obtain actinomycete isolates with the highest cellulase activity and to determine the morphological characteristics of the selected isolates. The research methodology included screening cellulolytic actinomycetes on cellulase medium, macroscopic observations including colony shape and texture, as well as the color of the substrate and aerial mycelium and microscopic observations including spore chain structure using the cover slip method and Gram staining followed by identification to the genus level based on literature references. The results showed that all 24 selected actinomycete isolates exhibited cellulolytic activity. The actinomycete isolates with the highest cellulase activity were DP2, DP11, DP15, and DP19. Morphological observations showed that isolates DP2, DP11, DP15, and DP19 had powdery colony textures and circular colony shapes, while Gram staining results indicated that all of these isolates were Gram-positive bacteria. The spore chain structure in isolates DP2, DP11, and DP15 was open spiral, whereas isolate DP19 had a closed spiral spore chain. Based on these spore chain structures, isolates DP2, DP11, DP15, and DP19 belong to the genus Streptomyces.