Update Artikelilmiah: 54314

EKA NURUL KUSUMAWATI

NIM

Judul Artikel

Abstrak (Bhs. Indonesia)

Eceng gondok (Eichhornia crassipes) merupakan gulma air yang memiliki kemampuan pertumbuhan yang cepat. Pertumbuhan yang cepat tersebut, diduga didukung oleh bakteri endofit yang berperan dalam merangsang pertumbuhan tanaman (plant growh promoting) E. crassipes. Dua sifat penting bakteri endofit yang mendukung pertumbuhan tanaman antara lain penambatan nitrogen dan penghasil  hormon pertumbuhan Indole Acetic Acid (IAA). Eksplorasi bakteri endofit penambat nitrogen dan penghasil IAA dari akar E. crassipes yang tumbuh di lingkungan Bendung Gerak Sungai Serayu belum pernah dilakukan. Penelitian ini bertujuan untuk mengisolasi bakteri endofit akar E. crassipes dari lingkungan Bendung Gerak Sungai Serayu yang memiliki kemampuan penambatan nitrogen dan menghasilkan IAA.

Penelitian telah dilakukan selama 5 bulan dimulai pada bulan Februari-Juni 2026 dengan metode survei. Variabel bebas dalam penelitian ini adalah isolat bakteri dari akar eceng gondok, sedangkan variabel terikat meliputi kemampuan bakteri menambat nitrogen dan menghasilkan IAA. Parameter yang diamati meliputi perubahan warna media NFB, konsentrasi amonium, perubahan warna uji IAA, konsentrasi IAA, serta karakteristik isolat bakteri terpilih. Pengambilan sampel dilakukan di lingkungan Sungai Serayu. Isolasi, pengujian kemampuan bakteri dalam menambat nitrogen dan menghasilkan IAA, serta karakterisasi bakteri dilakukan di Laboratorium Mikrobiologi Fakultas Biologi Universitas Jenderal Soedirman. Data aktivitas penambatan nitrogen dan aktivitas produksi IAA dianalisis secara deskriptif. Hasil karakterisasi isolat bakteri mengacu pada Bergey’s Manual of Determinative Bacteriology untuk mengetahui identitas isolat bakteri.

Sebanyak lima isolat mampu menambat nitrogen (isolat EGS04, EGS05, EGS07, EGS09, dan EGS11) berkisar antara 0,808–1,591 ppm, dengan nilai tertinggi ditunjukkan oleh isolat EGS05 sebesar 1,591 ppm. Selain itu, dua isolat mampu menghasilkan IAA (EGS02 dan EGS05) berkisar 26,892-61,363 ppm. Aktivitas penambatan nitrogen dan produksi IAA tertinggi dihasilkan oleh isolat EGS05. Hasil pengujian karakterisasi isolat EGS05 secara fenotipik menunjukkan bahwa isolat EGS05 termasuk dalam genus Bacillus. Penelitian ini membuktikan akar E. crassipes merupakan habitat potensial bagi bakteri endofit yang mampu menambat nitrogen dan menghasilkan IAA.

Abtrak (Bhs. Inggris)

Water hyacinth (Eichhornia crassipes) is an aquatic weed characterized by its rapid growth rate. This rapid growth is presumed to be supported by endophytic bacteria that function as plant growth-promoting bacteria (PGPB). Two important traits of endophytic bacteria that contribute to plant growth are nitrogen fixation and the production of the phytohormone indole-3-acetic acid (IAA). The exploration of nitrogen-fixing and IAA-producing endophytic bacteria from the roots of E. crassipes growing in the Serayu River Barrage area has not previously been reported. Therefore, this study aimed to isolate endophytic bacteria from the roots of E. crassipes collected from the Serayu River Barrage area and to observe their ability to fix nitrogen and produce IAA.
This study was conducted over a five-month period, from February to June 2026, using a survey method. The independent variable was the bacterial isolates obtained from the roots of water hyacinth, while the dependent variables were the ability of the isolates to fix nitrogen and produce IAA. The observed parameters included changes in the color of the nitrogen-free bromothymol blue (NFB) medium, ammonium concentration, color changes in the IAA assay, IAA concentration, and the characteristics of the selected bacterial isolate. Root samples of E. crassipes were collected from the Serayu River. Isolation of endophytic bacteria, observation of their nitrogen-fixing and IAA-producing abilities, and bacterial characterization were carried out at the Microbiology Laboratory, Faculty of Biology, Universitas Jenderal Soedirman. Data on nitrogen-fixing activity and IAA production were analyzed descriptively. The characterization results were compared with the criteria described in Bergey's Manual of Determinative Bacteriology to determine the identity of the bacterial isolates.
Five isolates (isolates EGS04, EGS05, EGS07, EGS09, and EGS11) demonstrated nitrogen-fixing ability, with concentrations ranging from 0.808-1.591 ppm, and the highest value was observed in isolate EGS05 (1.591 ppm). In addition, two isolates (EGS02 and EGS05) were able to produce IAA, with concentrations ranging from 26.892-61.363 ppm. The highest nitrogen-fixing activity and IAA production were exhibited by isolate EGS05. Phenotypic characterization of isolate EGS05 indicated that it belongs to the genus Bacillus. This study demonstrates that the roots of E. crassipes constitute a potential habitat for endophytic bacteria capable of nitrogen fixation and IAA production.

Kata kunci

Pembimbing 1

Pembimbing 2

Pembimbing 3

Tahun

Jumlah Halaman