%0 Thesis %9 Skripsi %A Axelindo Suswantoro, NIM.: 20106040010 %B FAKULTAS SAINS DAN TEKNOLOGI %D 2025 %F digilib:72907 %I UIN SUNAN KALIJAGA YOGYAKARTA %K Antibakteri, Bioefikasi, Uji Postulat Koch, Pseudomonas Viridiflava, Uji In Vitro) %P 42 %T BIOEFIKASI BAKTERI DARI KULIT KATAK SEBAGAI BIOKONTROL BAKTERI Pseudomonas viridiflava PENYEBAB PENYAKIT BUSUK LUNAK PADA ANGGREK BULAN (Phalaenopsis sp.) %U https://digilib.uin-suka.ac.id/id/eprint/72907/ %X Soft rot disease in Phalaenopsis orchids (Phalaenopsis sp.) is caused by the bacterium Pseudomonas viridiflava, which can rapidly damage plant tissue. This study aims to isolate and characterize the pathogenic bacteria causing soft rot in Phalaenopsis sp.. Characterization was performed using the LOPAT test, and identification was based on macroscopic and microscopic characteristics, as well as pathogenicity tests. In this study, the antagonistic activity of bacterial isolates ScV9 and ScD9, isolated from the skin of the Sumatran frog Crassiovis, was also tested. The results showed that the pathogenic isolate causing soft rot in Phalaenopsis orchids was successfully isolated with the isolate code PsOrc, having a profile of L−, O−, P+, and was proven pathogenic through the Koch's postulates test. Based on macroscopic and microscopic characteristics, along with the LOPAT test, the bacterial isolate PsOrc is strongly suspected to be the species P. viridiflava. In vitro antagonistic tests showed that ScV9 produced an inhibition zone of 9.3 mm (moderate category) and was more effective than ScD9 (2.21 mm; weak category). It can be concluded that the ScV9 bacterium is more effective in inhibiting the growth of PsOrc. %Z Lela Susilawati, S. Pd., M. Si., PhD.