SKRINING DAN IDENTIFIKASI MIKROBA LIGNINOLITIK PADA PENGOMPOSAN ALAMI TANDAN KOSONG KELAPA SAWIT

Abstract

Screening and Identification of Ligninolytic Microbes in the Natural Decomposition of Oil Palm Empty Fruit Bunch  ABSTRACTOPEFB (oil palm empty fruit bunch)could potentially be utilized as organic fertilizer or animal feed through composting. Information on microorganisms that play important roles in the natural decomposition of OPEFB is to date not much known yet. This research was aimed to obtain and, subsequently, to molecularly identify lignin-degrading microbial isolates responsible for naturally decomposing OPEFB in the Oil Plant Plantation and Palm Oil Refinery Plant, PTPN VIII Cikasungka, Bogor. Screening for active lignin-degrading isolates was carried out on 17 naturally decomposing OPEFB samples. A total of 19 isolates of fungi and 80 isolates of bacteria were obtained. Ligninolytic activity was measured by Sundman and Nase testing methods. Ligninolytic activity was found on 13 fungal isolates and 15 bacterial isolates. The active isolates were subsequently identified molecularly based on ITS sequence in the ribosome DNA area for fungi and in 16S rRNA genes for bacteria. The results showed that the lignin-degrading microorganisms obtained consisted of 5 bacterial isolates from the genus Bacillus and 3 fungal isolates from the genus Rhizopus and Aspergillus. Keywords: composting, lignin, microbes, OPEFB, 16S rRNA ABSTRAKTKKS (tandan kosong kelapa sawit) berpotensi dimanfaatkan sebagai pupuk organik atau pakan ternak dengan cara pengomposan. Informasi mikroba yang berperan dalam pengomposan alami TKKS hingga saat ini belum banyak diketahui. Penelitian ini bertujuan mendapatkan isolat mikroba pendegradasi lignin dalam pengomposan alami TKKS asal Perkebunan dan Pabrik Pemerasan Kelapa Sawit, PTPN VIII Cikasungka, Bogor, serta mengidentifikasi mikroba tersebut secara molekuler. Skrining mikroba aktif pendegradasi lignin dilakukan terhadap 17 sampel TKKS yang sudah lapuk secara alami. Sebanyak 19 isolat jamur dan 80 isolat bakteri telah dihasilkan. Aktivitas ligninolitik diukur dengan metode pengujian Sundman dan Nase. Isolat jamur yang memiliki aktivitas ligninolitik sebanyak 13 isolat, sedangkan bakteri sebanyak 15 isolat. Isolat-isolat aktif tersebut selanjutnya diidentifikasi secara molekuler berdasarkan pada sekuen ITS di daerah DNA ribosom untuk jamur dan menggunakan gen 16S rRNA untuk bakteri. Hasil menunjukkan bahwa 5 isolat bakteri yang memiliki kemampuan mendegradasi lignin berasal dari genus Bacillus, sedangkan 3 isolat jamur pendegradasi lignin berasal dari genus Rhizopus dan Aspergillus Kata Kunci: lignin, mikroba, pengomposan, TKKS, 16S rRNA