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Pot experiment was conducted to observe the effect of frass (insect feces) from Black Soldier Fly larvae (BSFL) as soil amendments at different application rates in comparation with other organic fertilizers on Pakchoi (Brassica rapa L). The experimental design was completely random with seven treatments, namely compost, compost+LOB (liquid organic biofertilizer), 5%, 10%, and 15% BSF frass, chemical fertilizer (NPK, equivalent to 10 kg/ha), and soil as a control. After 35 days planting, the result showed that Pakchoi cultivated with compost+LOB, compost, and BSF frass produced the highest biomass compared to control and NPK treatment significantly. The highest total plant weight was achieved in the treatment of Compost+LOB (24.4 gr), followed by 10% BSF frass (23.3 gr), compost (21.8 gr), 15% BSF frass (20.7 gr), 5% BSF frass (19,8 gr), NPK (1.3 gr ) and control soil (0.9 gr). While the chlorophyll content was not significantly different between all treatments, the application of BSF frass tended to be higher but with curly leaf symptoms than other treatments. The population of P solubilizing bacteria and the activity of PME-ase enzyme in soil were also higher in the treatment of compost, compost+LOB, and BSF frass compared to control and NPK treatment.

Abstrak. Dewi TK, Suryanggono J, Agustiyani D. 2016. Isolasi dan uji aktivitas bakteri penghasil hormon tumbuh IAA (Indole-3-Acetic Acid) dan Bakteri Perombak Protein dari Tanah Pertanian Tual, Maluku Tenggara. Pros Sem Nas Masy Biodiv Indon 2: 271-276.Tanah pertanian yang terletak di daerah Tual, Maluku Tenggara memiliki keragaman mikrobaa dengan berbagai aktivitas antara lain penghasil hormon tumbuh IAA (Indole -3-Acetic acid) dan perombak protein. Bakteri yang mampu menghasilkan IAA dapat meningkatkan pertumbuhan dan perpanjangan akar sehingga permukaan akar menjadi lebih luas dan akhirnya tanaman mampu menyerap nutrisi dari dalam tanah lebih banyak. Bakteri yang mampu menghasilkan enzim protease memiliki kemampuan untuk mengurai atau menghilangkan protein kompleks pada lingkungan yang tercemar sehingga dapat berperan dalam bioremediasi lingkungan. Penelitian ini bertujuan untuk isolasi dan uji aktivitas bakteri penghasil hormon tumbuh IAA dan bakteri perombak protein dari Ohoitel, Kota Tual, Maluku Tenggara . Isolasi dan seleksi di lakukan dengan metode TPC (Total plate count) pada media TSB (Triptic Soy Broth) dan skim milk agar. Uji aktivitas bakteri penghasil IAA di lakukan secara kualitatif dan kuantitatif. Metode yang di gunakan adalah spektrofotometri pada panjang gelombang 530 nm dan HPLC (High Performance Liquid Chromatography). Pada HPLC kolom yang digunakan adalah C-18 reverse phase dengan detektor UV-Visible pada panjang gelombang 280 nm. Pengukuran aktivitas enzim protease di lakukan dengan metode spektrofotometri pada panjang gelombang 442 nm. Hasil penelitian menunjukkan bahwa isolat 8 Tual mampu menghasilkan IAA tertinggi yaitu 64 ppm. Aktivitas enzim protease tertinggi di tunjukkan oleh isolat TL7C dan TL5B sebesar 635 unit/mL dan 551,6 unit/mL pada waktu 36 jam Kata kunci: Bakteri, Tual, Indole-3-acetic acid, protease Abstract. Dewi TK, Suryanggono J, Agustiyani D. 2016. Isolation and activity test of IAA and protease producing bacteria from Tual Agricurtural Land, Southeast Maluku. Pros Sem Nas Masy Biodiv Indon 2: 271-276. Indole-3-Acetic Acid producing bacteria may increase the growth and extension of the root and make the root surface becomes more widespread and eventually the plant is able to absorb more nutrients from the soil. Proteases producing bacteria has the ability to break down or eliminate the protein complexes in a polluted environment so that it can play a role in environmental bioremediation. The aim of this study was to isolation and activity test of growth hormone-producing bacteria and proteases producing bacteria from Ohoitel agricultural land, Tual, South East Maluku. Isolation and selection were done by total plate count method on the Triptic Soy Broth and skim milk agar medium. IAA-producing bacteria activity test was done qualitatively and quantitatively. The method used was spectrophotometry at 530 nm and HPLC (HighPerformance Liquid Chromatography) with C-18 reverse phase column at 280 nm. Protease enzyme activity measurements were done by the spectrophotometric ...

In fi eld experiments during dry season 2010, the effects of biofertilization on growth of fruit yield Semangka (Citrullus lanatus) and of biochemical properties of soil were investigated. The experimental design was Randomly Block Design (RBD) with four treatments and fi ve replications. The treatments were biofertilizer only; chemical fertilizer only; biofertilizer plus a half dose of chemical fertilizer, and control. The application of biofertilizer which was a mixture of Pseudomonas sp., Bacillus sp. and Streptomyces sp and chemical fertilizers (only 50% of the recommended dosage of NPK) increased vegetative growth (plant height, number of branches) compared to chemical fertilizer treatments only. An addition of biofertilizer with the chemical fertilizer also increased the biochemical properties as well as the yield of C. lanatus compared to other treatments. The possible role of biofertilizer on improving soil enzymatic activities, vegetative growths and yield will be discussed more detail in the paper.

Abstract. Agustiyani D, Dewi TK, Laili N, Nditasari A, Antonius S. 2021. Exploring biofertilizer potential of plant growth-promoting rhizobacteria candidates from different plant ecosystems. Biodiversitas 22: 2691-2698. Plant growth-promoting rhizobacteria (PGPR) have been widely used as inoculants to increase the growth of crops. This study aims to evaluate the effective PGPR strains according to their capability in various plant growth-promoting activities in vitro. Ten rhizosphere soil samples were obtained from several plant ecosystems in Bangkinang, Kampar, Sumatra Island, Indonesia. A total of 42 bacteria were isolated and tested for three plant growth–promoting activities i.e., phosphate solubilization, indole-3-acetic acid (IAA) production, and N fixation. Out of 42 isolates, 26 were positive for phosphate solubilization, 11 were positive for IAA production, and five were positive for N fixation. The qualitative and quantitative analysis of plant growth–promoting activities revealed that the highest phosphate solubilizing isolate was PK.4.2 (SI 4.33); the highest IAA-producing isolate was I.4.2 (73.1 ppm); while the highest N-fixing ability was NFB.1.1. According to the seed bioassay results, the shoot and root length of bok choy (Brassica rapa) seedlings were significantly enhanced with the PGPR isolates treatment. The highest shoot length (2.53 cm) was observed among seeds treated with I.4.2 isolate, followed by PK.6.1 (2.45 cm) and I.5.3 (2.07 cm). The NFB.1.1 isolate promoted the longest root length (6.4 cm), although this was similar with I.5.3 isolate (6.11 cm). Two isolates that showed significant plant growth–promoting activities were analyzed using 16S rDNA sequences. The two isolates had a close evolutionary relationship with genus Sinomonas strain Cw 108 (I.4.2) and Arthrobacter (I.5.3.).

Background and Objectives: This study was aimed to isolate Rhizobium spp., from the plant rhizosphere and to investigate their effects on the growth of peanut (Arachis hypogaea L.) as plant growth-promoting rhizobacteria (PGPR). Materials and Methods: The isolates were characterized using YEMA, YEMA + Congo Red, and YEMA + Bromothymol blue (BTB) media. The Rhizobium was tested qualitatively for their ability to produce indole acetic acid (IAA), siderophores, proteases, nitrogenases as well as phosphate solubilizing activity. A greenhouse experiment was carried out to elucidate the effect of Rhizobium inoculation on Arachis hypogaea L. growth. Results: Eleven isolates were obtained in YEMA media and they were red-pink in the YEMA + Congo Red media. The YEMA + BTB test showed that 2 isolates were slow-growing and the rest were fast-growing isolates. Seven isolates produced siderophores, 5 were capable of phosphate solubilizing, 9 isolates produced protease enzyme, 4 isolates could produce IAA, and 7 isolates could fix nitrogen. The B1 and the combination of some high trait-isolate treatments in Y gave the best results on Arachis hypogaea L. growth. Conclusion: These isolates can be developed as biological fertilizer agents for the peanut plant.

The physiological character, especially the effect of pH and organic substrate on the growth and activity of some ammoniaoxidizing bacteria was carried out. The results show that eight out of twenty isolates have ability to reduce ammonium, two of them i.e. isolate AOB1 and AOB2 could reduce more than 90% of ammonium. The growth and activity to reduce ammonium to nitrite was attained optimum at pH 7-8. From the result also indicated that the growth and activity of both isolate AOB1 and AOB2 were higher on the organic carbon (acetate)-containing media. This finding indicated that both of isolate AOB1 and AOB2 were heterotrophic ammonia-oxidizing bacteria.

Penyakit layu Fusarium pada tanaman pisang yang diakibatkan oleh Fusarium oxysporum f. sp. cubense merupakan salah satu penyakit yang sangat merusak tanaman pisang di daerah tropik. Pengendalian penyakit layu secara biologi menjadi salah satu solusi. Penelitian ini bertujuan mendapatkan agens pengendali F. oxysporum f. sp. cubense yang potensial. Bakteri dan aktinomiset diisolasi dari sampel tanah perakaran tanaman pisang di Lampung dan Cianjur. Sebanyak 64 isolat aktinomiset dan 142 isolat bakteri diperoleh dari lokasi tersebut. Uji antagonis terhadap F. oxysporum f. sp. cubense dari isolat tersebut menunjukkan bahwa 10 isolat aktinomiset dan 21 isolat bakteri positif memiliki daya hambat. Isolat aktinomiset memperlihatkan kemampuan menghambat F. oxysporum f. sp. cubense relatif lebih tinggi dibandingkan dengan bakteri. Isolat-isolat yang bersifat antagonis terhadap F. oxysporum f. sp. cubense diuji aktivitas enzim protease, kitinase, dan selulase secara kualitatif pada medium spesifik. Semua isolat aktinomiset yang diuji mempunyai aktivitas enzim kitinase, tetapi hanya 5 isolat bakteri mempunyai aktivitas enzim tersebut. Sebanyak 13 isolat bakteri memiliki aktivitas enzim protease dan hanya 1 isolat aktinomiset yang mempunyai aktivitas protease. Dua isolat bakteri (L.II.4.ND dan L.A.I-5.DW) dan 3 isolat aktinomiset (L.A.I.DW, L.3.1.DW dan Ci.I.A5.DW) mampu menghambat F. oxysporum f. sp. cubense cukup tinggi dan mempunyai aktivitas enzim lisis. Isolat memiliki homologi 99% dengan Klebsiella pneumonia (L.II.4.ND), Burkholderia sp. (L.A.I-5.DW), Streptomyces sp. (L.A.I.DW), Streptomyces sp. (L.3.1.DW), dan Streptomyces sp. (Ci.I.A5.DW).