Article Per Year (5 Year)
p-Index From 2021 - 2026
0.778
P-Index
This Author published in this journals
All Journal HAYATI Journal of Biosciences Jurnal Ilmiah RESPATI Agriculture and Biological Technology
Rahmatullah, Rifki
Unknown Affiliation
Agriculture, Biological Sciences & Forestry Biochemistry, Genetics & Molecular Biology Earth & Planetary Sciences Environmental Science

Published : 4 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 4 Documents
Search

 1 
Efficiency of Bacillus pseudomycoides RAY21 and Bacillus subtilis CYA27 Endospore Formulation on Biochar and Oil Spill Dispersant Rahmatullah, Rifki; Anwar, Saiful; Yani, Mohamad; Firlandiana, Maulidi
HAYATI Journal of Biosciences Vol. 32 No. 2 (2025): March 2025
Publisher : Bogor Agricultural University, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.4308/hjb.32.2.374-386

Abstract

Bacillus sp. is well known for its functional capabilities such as solubilizing phosphorus (P) and potassium (K), and fixing nitrogen (N2). These bacteria can form endospores under stressed conditions, allowing long-term survival and application in biotechnological fields. This study aims to isolate Bacillus sp. capable of forming endospores and evaluates their viability on different carriers, specifically biochar and oil spill dispersant (OSD), to enhance biodegradation in contaminated environments. Soil samples from the bamboo rhizosphere were heat-shocked to isolate endospore-forming Bacillus strains, with the isolate identified as Bacillus pseudomycoides RAY21 through 16S rRNA sequencing. This strain exhibited Gram-positive characteristics, formed endospores, and demonstrated potential on various media such as Pikovskaya, Alexandrov, and N-Free Mannitol. The physiological characterization indicated optimal growth in a pH range of 6-8, salinity up to 3.5%, and thermophilic properties. Endospores from B. pseudomycoides RAY21 and B. subtilis CYA27 were tested on biochar and OSD as carriers. The results showed that endospores adhered better to biochar, but their viability was more stable in OSD over time. Notably, B. pseudomycoides RAY21 on OSD degraded 23.43% of total petroleum hydrocarbons (TPH), outperforming B. subtilis CYA27 (21.62%). In conclusion, the study demonstrates the potential of using Bacillus endospores on OSD as an effective carrier for bioremediation, particularly in degrading petroleum hydrocarbons. Future research should focus on optimizing carrier materials and exploring field-scale applications for enhanced environmental cleanup.
Karakterisasi dan Uji Kemampuan Fungi Pelarut Posfat dan Kalium Mudrikah, Siti; Ayu, Intan Putri Puspitaning; Rahmatullah, Rifki
Agriculture and Biological Technology Vol. 2 No. 1 (2024): Desember
Publisher : Science, Technology, and Education Care

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.61761/agiotech.2.1.15-21

Abstract

Fosfor dan kalium adalah unsur hara makro penting bagi tanaman, namun sering kali tidak tersedia dalam bentuk yang dapat diserap oleh tanaman di tanah. Penggunaan pupuk kimia secara berkelanjutan dapat menyebabkan pencemaran lingkungan. Fungi pelarut fosfor (P) dan kalium (K) merupakan mikroorganisme yang berperan dalam meningkatkan ketersediaan kedua unsur hara ini dengan mengubah bentuknya menjadi lebih mudah diserap tanaman. Pendekatan biologis ini lebih ramah lingkungan dibandingkan dengan penggunaan pupuk kimia, terutama pada lahan masam. Penelitian ini bertujuan untuk mengidentifikasi karakteristik morfologi makroskopis dan mikroskopis fungi pelarut P dan K serta mengetahui indeks kelarutan fosfat dan kalium. Hasil penelitian menunjukkan bahwa karakter morfologi fungi pelarut P dan K mencakup warna koloni depan hitam di tengah dan putih di tepi, warna belakang kuning tua, diameter koloni ±5 cm, bentuk koloni tak beraturan, dan tekstur halus seperti kapas. Indeks pelarutan fosfat dan kalium masing-masing adalah 2,35 dan 2,23, yang tergolong dalam kategori intermediate. Fase adaptasi dimulai pada 0 jam hingga 24 jam, fase pertumbuhan awal antara 24 hingga 48 jam, fase logaritmik antara 48 hingga 144 jam, dan fase pertumbuhan lambat antara 168 hingga 216 jam, dengan fase stasioner belum terbentuk
Karakterisasi Bakteri Perakaran Vegetasi Kedelai, Singkong dan Rumput Mudrikah, Siti; Sari, Intan Nirmala; Rahmatullah, Rifki; Estiningtyas, Rizki
Agriculture and Biological Technology Vol. 2 No. 1 (2024): Desember
Publisher : Science, Technology, and Education Care

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.61761/agiotech.2.1.6-14

Abstract

Tanah merupakan faktor lingkungan yang penting, sebab selain mempunyai hubungan timbal balik dengan tanaman yang tumbuh diatasnya, tanah juga memiliki hubungan timbal balik dengan mikroba tanah yang ada di dalamnya. Isolat bakteri yang diisolasi dari sumber isolat dari tanah dengan vegetasi berbeda yaitu kedelai dengan kode isolat K1104 (1), K2106 (2), rumput dengan kode isolat R2104 (2) dan singkong dengan kode isolat S2104 (1). Hasil penelitian menunjukkan bahwa kode Isolat K1104 (1) memiliki bentuk sel coccus, Gram negatif, memiliki enzim katalase, enzim dehidrogenase, bersifat motil, obligate aerob, tidak memiliki enzim urease serta tidak dapat memfermentasikan karbohidrat, dapat tumbuh direntan suhu 27-37 oC dan pH 3-9 serta dapat tumbuh pada kadar salinitas 2% dan 5%. Isolat K2106 (2) bentuk sel basil, Gram negatif memiliki enzim katalase, enzim dehidrogenase, bersifat motil, obligate aerob, tidak memiliki enzim urease serta tidak dapat memfermentasikan karbohidrat, dapat tumbuh direntan suhu 27-37 oC dan pH 3-9 serta dapat tumbuh pada kadar salinitas 5%. Isolat R2104 (2) bentuk sel coccus, Gram positif memiliki enzim katalase, enzim dehidrogenase, bersifat motil, Fakultatif anaerob, tidak memiliki enzim urease serta dapat memfermentasikan karbohidrat, dapat tumbuh direntan suhu 5-37 oC dan pH 6-9 serta dapat tumbuh pada kadar salinitas 2%. Isolat S2104 (1) bentuk sel coccus, Gram negatif memiliki enzim katalase, enzim dehidrogenase, bersifat motil, obligate aerob, tidak memiliki enzim urease serta tidak dapat memfermentasikan karbohidrat, dapat tumbuh direntan suhu 27-37 oC dan pH 6-9 serta dapat tumbuh pada kadar salinitas 2%.
Artikel Review: Produksi dan Aplikasi α-Amilase Bakteri Psikrofilik di Bidang Pangan Nurjasmi, Reni; Aprilia, Sarah; Ruhimat, Riki; Rahmatullah, Rifki
JURNAL PERTANIAN Vol 16, No 3 (2025): Jurnal Ilmiah Respati
Publisher : Universitas Respati Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.52643/jir.v16i3.7421

Abstract

Psychrophilic bacteria have been widely found in extreme low-temperature environments such as the Arctic and Antarctic oceans and glacial lakes. Some of these bacteria possess the hydrolytic enzyme α-amylase, which functions to hydrolyze starch into simple sugars such as maltose, maltotriose, and glucose. The structure of psychrophilic α-amylase is highly flexible due to reduced hydrophobic interactions and an increased number of hydrophilic residues. This unique structure allows the enzyme to function optimally at low temperatures, specifically 0–20 °C. High-quality enzymes can be obtained through integrated production stages, including the isolation of psychrophilic bacteria, low-temperature fermentation, and stepwise purification. Response Surface Methodology is often employed to achieve high yet economical enzyme yields. The enzyme isolated from psychrophilic bacteria is purified through ammonium sulfate precipitation, dialysis, and several chromatographic techniques performed sequentially to obtain a pure enzyme ready for characterization. Biochemical characterization reveals high enzyme activity at low temperatures, an optimal pH range of 6.5–8.0, and a strong dependence on calcium ions to maintain structural stability. Kinetic analysis shows that psychrophilic α-amylase has a low Michaelis constant (Km), indicating high substrate affinity that enables optimal performance even when substrate availability is limited. These advantages are widely utilized in various fields, particularly the food-processing industry, such as syrup production, baking, fermented beverages, and frozen-food processing. The ability of α-amylase to function at low temperatures provides significant benefits for food processing because it reduces energy requirements, thereby lowering production costs. The application of psychrophilic α-amylase also offers a promising solution for achieving environmentally friendly food-processing industries.
Co-Authors Aprilia, Sarah Ayu, Intan Putri Puspitaning Estiningtyas, Rizki Maulidi Firlandiana Moh. Yani Reni Nurjasmi, Reni Ruhimat, Riki Saiful Anwar Sari, Intan Nirmala siti mudrikah