Populasi Khamir Endofit Buah Sirsak (Annona Muricata L.) serta Kemampuannya Menghasilkan Asam Indol Asetat dan Melarutkan Fosfat

Abstract

Soursop contains high diversity of endophytic yeasts. This study aims to isolate and identify endophytic yeast of soursop fruit and their potential to produce indole acetic acid and dissolve phosphate. Endophytic yeasts were isolated using Malt Extract Agar (MEA) medium and characterized macroscopically and microscopically. Qualitative and quantitative determination of yeast producing indole acetic acid (IAA) was determined using a spectrophotometer with an optical density (OD) of 530 nm. The ability of each endophytic yeast to dissolve phosphate using Pikovskaya medium was characterized by the clear zone colonies that formed surrounding the colony. The results showed that Rhodotorula had the highest population, especially Rhodotorula sp. (27×1011 CFU/ml) followed by Kloeckera sp. (20×1011 CFU/ml), Candida sp. (18×1011 CFU/ml), and R. mucilaginosa (15×1011 CFU/ml). All endophytic yeasts were potential to produce IAA and dissolve phosphate. Candida sp. produced the highest IAA (26.00 ppm) followed by R. mucilaginosa (17.51 ppm), Rhodotorula sp. (10.26 ppm), and Kloeckera sp. (2.23 ppm). Candida sp. also had the highest phosphate solubilization index 7.71.