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"Telah dilakukan penelitian mengenai potensi bakteri basil indigenous sebagai plant growth promoting bacteria (PGPB). Isolat G7, G10 dan G18 yang berpotensi dalam meningkatkan pertumbuhan tanaman diisolasi dari saluran pencernaan larva lalat tentara hitam, sedangkan isolat B. siamensis LDR dengan potensi sebagai agen biokontrol diisolasi dari cocopeat. Penelitian ini dilakukan untuk untuk mengetahui karakterisasi pertumbuhan dari isolat G7, G10 dan G18, meliputi pH medium (5, 6, 7, 8, 9) dan suhu inkubasi (30, 40, 50 oC). Uji antagonisme dilakukan antara isolat G7, G10 dan G18 dengan B. siamensis LDR guna melihat kemungkinan isolat-isolat tersebut untuk disatukan dalam satu konsorsium. Uji kemampuan memfiksasi nitrogen dan memproduksi siderofor dilakukan pada isolat G7, G10, G18 dan B. siamensis LDR.  Hasil menunjukkan bahwa isolat G7, G10 dan G18 dapat tumbuh pada pH 5—9 dengan pertumbuhan optimum pada kisaran pH 7—9. Suhu optimum bagi ketiga isolat diketahui pada 40 oC. Terdapat hubungan antagonisme isolat G7, G10 dan G18 terhadap B. siamensis LDR sehingga isolat-isolat tersebut tidak dapat disatukan dalam satu konsorsium. Kemampuan memfiksasi nitrogen ditunjukkan oleh isolat G7 dan G10. Kemampuan memproduksi siderofor dimiliki oleh semua isolat, yaitu G7, G10, G18 dan juga B. siamensis LDR. Isolat G7 dan G10 yang mampu memfiksasi nitrogen serta memproduksi siderofor merupakan isolat yang lebih unggul karena memiliki karakteristik PGPB yang lebih lengkap.

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Research has been carried out on the potential of several indigenous bacili bacteria as plant growth promoting bacteria (PGPB). Isolates G7, G10 and G18 with potential to increase plant growth were isolated from the digestive tract of black soldier fly larvae, while B. siamensis LDR with potential as a biocontrol agent was isolated from cocopeat. This research was conducted to determine the growth characteristics of isolates G7, G10 and G18, including medium pH (5, 6, 7, 8, 9) and incubation temperature (30, 40, 50 oC). Antagonism test was carried out between isolates G7, G10 and G18 against B. siamensis LDR to see the possibility of these isolates to be combined in one consortium. The ability to fix nitrogen and produce siderophores were carried out on isolates G7, G10, G18 and B. siamensis LDR. The results showed that isolates G7, G10 and G18 could grow at pH 5—9 with optimal growth in the range of pH 7—9. The optimum temperature for the three isolates was at 40 oC. There was an antagonistic relationship between isolates G7, G10 and G18 towards B. siamensis LDR so these isolates could not be combined into one consortium. The ability to fix nitrogen was shown by isolates G7 and G10. The ability to produce siderophores was shown by all isolates, namely G7, G10, G18 and also B. siamensis LDR. Isolates G7 and G10 which are able to fix nitrogen and produce siderophores, were the best isolates because they have more complete characteristics as PGPB."

"Pertanian merupakan salah satu sektor yang mendukung dalam pemenuhan kebutuhanpangan di Indonesia. Peningkatan jumlah penduduk yang ada di Indonesia setiap tahuntidak sebanding dengan hasil panen pertanian yang semakin menurun. Pemilihan pupukkimia untuk meningkatkan hasil pertanian dinilai tidak efektif karena dinilai tidak ramahlingkungan. Salah satu cara alternatif untuk meningkatkan hasil panen adalah denganmemanfaatkan bakteri sebagai pendukung pertumbuhan tanaman atau Plant GrowthPromoting Bacteria (PGPB). Penelitian ini bertujuan mendapatkan bakteri yangberpotensi sebagai pendukung pertumbuhan tanaman meliputi kemampuan dalamproduksi Indole Acetic Acid (IAA), pelarutan fosfat, kitinase, dan selulase. Larva lalattentara hitam dinilai dapat menjadi sumber bakteri karena kemampuan konversi biowasteyang relatif cepat, sehingga diduga berkorelasi dengan bakteri yang terdapat di larva.Isolasi bakteri dari larva lalat tentara hitam dilakukan pada fase larva instar I dan Vdengan 4 variasi medium isolasi (Casein Starch Agar, Carboxymethyl Cellulose agar,Yeast Extract-suplemented Minimal agar, dan Skim Milk Agar). Setiap isolat yang telahdidapat telah berhasil dilakukan penapisan produksi IAA, aktivitas pelarutan fosfat,aktivitas enzim selulolitik, dan aktivitas enzim kitinolitik. Selain itu, setiap isolat telahdilakukan karakterisasi secara morfologi dan sifat biokimia. Sebanyak 22 isolat telahdidapatkan dengan kode B1-B22, 5 (B1, B11, B15, B16, dan B21) dari seluruh isolattersebut memiliki hasil positif pada dua penapisan uji aktivitas dan 9 isolat memiliki hasilpositif pada satu penapisan uji aktivitas. Isolat B21 merupakan isolat terbaik karenamemiliki hasil positif pada dua uji (uji aktivitas enzim selulolitik dan kitinolitik) danmemiliki nilai tertinggi pada kedua uji tersebut. Isolat B21 diduga berasal dari dari genusGardnerella atau Haemophilus berdasarkan tabel identifikasi.

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Agriculture is one of the sectors that support the fulfillment of food demand in Indonesia.

Increasing in the number of people in Indonesia every year is not proportional to the

decreasing agricultural yields. The use of chemical compounds to increase agricultural

yields is considered ineffective because it can damage the surrounding environment. One

alternative way to increase crop yields is to use bacteria as Plant Growth Promoting

Bacteria (PGPB). This study aims to obtain bacteria that have the potential to support

plant growth including the ability to produce Indole Acetic Acid (IAA), phosphate

solubilization, chitinase, and cellulase. Black soldier fly (BSF) larvae are considered a

source of bacteria because their role in bioconversion of organic waste are thought to be

correlated with bacteria in BSF larvae. Isolation of bacteria from BSF larvae was carried

out using larval stages instars I and V with 4 variations of isolation medium (Casein

Starch Agar, Carboxymethyl Cellulose agar, Yeast Extract-supplemented Minimal agar,

and Skim Milk Agar). Isolates have been successfully screened for IAA production,

phosphate solubilization activity, cellulolytic enzyme activity, and chitinolytic enzyme

activity. In addition, each isolate has been characterized by morphological

characterization and biochemical tests. A total of 22 isolates were obtained with codes

B1-B22, five isolates (B1, B11, B15, B16, and B21) of these isolates had positive results

in two activity tests and nine isolates had positive results in one activity test. Isolate B21

was the best isolate because the isolate showed positive results in two tests (cellulolytic

and chitinolytic enzyme activity tests) and had the highest score in both tests. The isolate

B21 is believed to be a member of the genus Gardnerella or Haemophilus based on the

identification table."

"Penggunaan pupuk kimia secara terus menerus dan berlebihan dapat menurunkan kualitas tanah dan dapat menurunkan hasil panen. Salah satu solusi alternatif untuk mengembalikan kesuburan tanah adalah dengan menggunakan tambahan pupuk hayati. Pupuk hayati merupakan pupuk yang berisi mikroorganisme yang memiliki kemampuan meningkatkan pertumbuhan tanaman yang disebut dengan plant growth promoting bacteria (PGPB). Penelitian ini bertujuan untuk mendapatkan bakteri dari sampel kepala udang dilanjutkan karakterisasi jenis genus bakteri dan diuji kemampuan berdasarkan karakter PGPB untuk mendapatkan isolat potensial sebagai pupuk hayati. Isolasi dilakukan dengan teknik quadrant streak dari cairan suspensi pada medium umum. Isolat bakteri yang didapatkan selanjutnya dikarakterisasi berdasarkan Cowan & Steel’s Manual for the Identification of Medical Bacteria dan diuji kemampuannya menyediakan unsur hara bagi tanaman berdasarkan karakter PGPB, yaitu kemampuan memfiksasi nitrogen, melarutkan fosfat, menghasilkan IAA dan siderofor. Kemudian setiap isolat diuji kemampuan dalam menghasilkan enzim ekstraseluler (kitinase, protease, lipase dan amilase) menggunakan medium diferensial untuk mengetahui potesi mendegradasi makromolekul yang dapat dijadikan sumber nutrien bakteri. Hasil penelitian menunjukkan bahwa diperoleh lima isolat bakteri yang diberi kode UD1 hingga UD5, diantaranya 3 isolat Gram positif (UD1, UD4, dan UD5) dan 2 isolat Gram negatif (UD2 dan UD3). Uji kemampuan PGPB terhadap kelima isolat menunjukkan 3 isolat (UD1, UD2, dan UD3) mampu memfiksasi nitrogen, 3 isolat (UD2, UD3, dan UD5) mampu melarutkan fosfat, 4 isolat (UD1, UD2, UD3, dan UD4) mampu menghasilkan IAA, dan 3 isolat (UD2, UD3, dan UD4) mampu menghasilkan siderofor. Hasil uji kemampuan menghasilkan enzim ekstraseluler menunjukkan 2 isolat (UD2 dan UD3) positif terhadap keempat jenis uji. Berdasarkan data tersebut maka bakteri hasil isolasi berpotensi untuk dijadikan agen pupuk hayati.

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The excessive use of chemical fertilizers can decrease soil quality and lead to reduced crop yields. One alternative solution to restore soil fertility is by utilizing biofertilizers. Biofertilizers contain microorganisms with the ability to enhance plant growth, known as Plant Growth Promoting Bacteria (PGPB). This study aimed to isolate bacteria from shrimp head samples, characterize the genera of bacteria, and assess their PGPB characteristics to identify potential isolates for biofertilizer application.

Isolation was conducted using the quadrant streak technique from suspension fluid on a standard medium. The isolated bacteria were then characterized based on Cowan & Steel’s Manual for the Identification of Medical Bacteria and tested for their ability to provide nutrients to plants based on PGPB characteristics, including nitrogen fixation, phosphate solubilization, indole-3-acetic acid (IAA) and siderophore production. Subsequently, each isolate was tested for its ability to produce extracellular enzymes (chitinase, protease, lipase, and amylase) using differential media to determine their potential for degrading macromolecules as a bacterial nutrient source.

The results showed that five bacterial isolates were obtained, including 3 Gram-positive isolates (UD1, UD4, and UD5) and 2 Gram-negative isolates (UD2 and UD3). PGPB capability tests on these isolates revealed that 3 isolates (UD1, UD2, and UD3) could fix nitrogen, 3 isolates (UD2, UD3, and UD5) could solubilize phosphate, 4 isolates (UD1, UD2, UD3, and UD4) could produce IAA, and 3 isolates (UD2, UD3, and UD4) could produce siderophores. The results of the extracellular enzyme production test indicated that 2 isolates (UD2 and UD3) tested positive for all four types of tests. Based on this data, the isolated bacteria have the potential to be used as biofertilizer agents."

"Larva lalat tentara hitam (Hermetia illucens L.) atau BSF merupakan agen biologis yang umum digunakan dalam pengelolaan sampah organik. Kemampuan larva lalat tentara hitam dalam mencerna bahan organik didukung oleh berbagai aktivitas bakteri yang hidup di dalam saluran pencernaanya. Pencarian bakteri dengan berbagai aktivitas pendukung pertumbuhan dan proteksi tanaman berpotensi dalam mengurangi dampak akibat penggunaan pupuk dan pestisida sintetis. Penelitian ini dilakukan untuk mengisolasi, menghitung jumlah populasi bakteri, mengetahui potensi aktivitas isolat, serta mengarakterisasi bakteri saluran pencernaan larva BSF. Pengisolasian bakteri dilakukan dengan metode filtrasi membran dengan pengenceran bertingkat dan uji aktivitas dilakukan pada beberapa medium. Berdasarkan morfologi, sebanyak 21 isolat berhasil terisolasi dan hasil perhitungan kepadatan populasi bakteri pada sampel saluran pencernaan BSF, yaitu 1,136 x 1010 CFU/gr. Berdasarkan uji aktivitas isolat, sebanyak dua isolat memiliki aktivitas selulolitik, yaitu isolat G18 dan G21; empat isolat yang dapat mendegradasi kitin, yaitu isolat G9, G16, G18, dan G21; empat isolat dengan kemampuan pelarutan fosfat dan memproduksi IAA, yaitu isolat G7, G10, G13, dan G19. Isolat G18 dan G10 merupakan isolat terunggul karena isolat G18 memiliki keunggulan dalam proteksi tanaman, sedangkan isolat G10 unggul dalam mendukung pertumbuhan tanaman. Isolat G1 hingga G22 memiliki karakteristik yang beraneka ragam. Berdasarkan identifikasi bakteri secara biokimia, isolat G9, G10, G16, dan G18 memiliki karakteristik bakteri dari kelompok Bacillus.

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Black soldier fly (Hermetia illucens L.) larvae are biological agent that commonly used in organic waste management. The ability to digest organic compounds was known to be supported by the diversity of bacterial activities inside their body. The exploration of certain bacterial activities in promoting plant growth and protection may be needed to reduce the impact of synthetic fertilizers and pesticides uses. This study aims to isolate, enumerate the bacterial population from BSF larval gut, screening for potential activities, and characterize isolates. Isolation of bacteria was carried out by membrane filtration method combined with serial dilutions and the bacterial activities carried out on various media. A total of 21 bacteria were isolated from BSF larval gut and the bacterial population density is 1.136 x 1010 CFU/gr. The isolate activity test showed that; two isolates G18 and G21 were positives for cellulolytic activity; four isolates G9, G16, G18, and G21 were able to degrade chitin; four isolates G7, G10, G13, and G19 have the ability to solubilize phosphate and produce IAA. Isolates G18 and G10 were the best isolates because G18 had the advantage in plant protection, while G10 excelled in supporting plant growth. Isolates G1 to G22 had various characteristics. Based on the biochemical identification, isolates G9, G10, G16, and G18 had the characteristics of bacteria from the Bacillus group."

"Air limbah domestik dan pertanian telah menjadi masalah lingkungan disebabkan kandungan nitrogen dan fosfat berdampak pada eutrofikasi. Diketahui dari hasil studi menunjukan bahwa jenis mikroalga dapat mereduksi kadar nitrogen dalam limbah. Namun, pada umumnya limbah tidak memiliki nutrien cukup untuk pertumbuhan mikroalga. Pupuk diketahui menjadi sumber nutrien bagi tumbuhan, diduga dapat dimanfaatkan pula untuk pertumbuhan mikroalga. Tujuan dari penelitian ini adalah mengetahui pengaruh pemanfaatan pupuk terhadap pertumbuhan mikroalga dan kemampuan mikroalga mereduksi senyawa nitrat dan amonia. Penelitian ini membandingan tiga jenis mikroalga (Oscillatoria, Chlorella, dan Scenedesmus) pada tiga konsentrasi pupuk (0,01% (g/l); 0,02%; and 0,03%) dengan rata-rata kandungan awal nitrat dan amonia masing-masing 80 ppm pada pH netral berkisar 6,8-7,2. Setelah pengamatan selama 21 hari, terlihat penurunan konsentrasi amonia rata-rata diseluruh perlakuan sebesar 45 ppm dan peningkatan pada konsentrasi nitrat diseluruh perlakuan sebesar 37 ppm. Pertumbuhan populasi Scenedesmus terlihat paling baik dibandingkan mikroalga lainnya dengan nilai absorbansi rata-rata 0,79. Pada populasi Scenedesmus pH media menurun dari rata-rata 7,09 menjadi 4,62. Konsentrasi nitrit meningkat pada seluruh perlakuan mikroalga dengan konsentrasi pupuk 0,02% dan 0,03% dari rata-rata 0,37 ppm menjadi 5,20 ppm.

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Wastewater from domestic and agriculture activities become environmental problem due to nitrogen and phosphate content which can lead to eutrophication. Some microalgae has been proved can reduce amount of nitrate and ammonia content in wastewater. However most of wastewater lack of nutrient which needed by microalgae growth. Fertilizer has been known as source of nutrient and can improve the growth of plant. The objective of this study was to find correlation between nutrientand microalgae growth and ability to reduce nitrate and ammonium compounds. The research compared between three type of microalgae (Oscillatoria, Chlorella, and Scenedesmus) in three concentration of fertilizer (0,01% (g/l); 0,02%; and 0,03%) with average intial concentration of ammonium and nitrate each was 80 ppm and pH netral around 6,8-7,2.After 21 days observation, concentration of ammonium decreased 45 ppm in average and nitrate increased 37 ppm in average. Scenedesmus showed the best growth among others with average value of absorbance 0,79. In Scenedesmus population showed decreased of pH value from an average 7,09 to 4,62. Nitrite concentration has increased in all microalgae treatment with fertilizer concentration 0,02% and 0,03% with average nitrite value from 0,37 ppm to 5,20 ppm."

"Growth and yield of plants are increased when plants are provided with mixtures of nitrate and ammonium compared with either form alone. Therefore, the objective of this experiment was determine the optimum of nitrate and ammonium ratio caused an increased in growth and yield of green pak choy (Brassica chinensis L.) The experiment was designed in Randomized Completely Design with five treatments of nitrate ammonium ratios and arranged in four replication. The treatments of nitrate ammonium ratio were : 100/0; 75/25; 50/50; 25/75 and 0/100. The results showed that nitrogen fertilizer applied in mixture nitrate and ammonium gave different effects in leaf nitrate reductase activity, leaf nitrogen content, growth and yield of green pak choy. There was significant correlation between the leaf nitrate reductase activity and leaf nitrogen content. There was also significant correlation between the leaf nitrate reductase activity with growth and yield of green pak choy. Nitrate ammonium ratio at 75/25 and 50/50 have better affect on the leaf nitrate reductase activity, leaf nitrogen content, growth and yield of green pak choy"

"Shigella dysenteria merupakan etiologi dari shigellosis. Bakteri ini menginfeksi manusia melalui jalur fekal-oral dan menyerang sistem gastrointestinal. Sementara itu, Staphylococcus epidermidis merupakan salah satu etiologi tersering kasus infeksi nosokomial khususnya pada penggunaan alat-alat kesehatan. Infeksi yang disebabkan oleh kedua bakteri ini masih banyak ditemukan di negara berkembang, salah satunya Indonesia. Tata laksana definitif dalam mengatasi penyakit yang disebabkan oleh kedua bakteri ini adalah pemberian antibiotik adekuat. Akan tetapi, telah terjadi peningkatan resistensi antibiotik terhadap kedua bakteri ini, sehingga sangat diperlukan penemuan kandidat antibiotik baru. Kandidat antibiotik baru yang berpotensi mengatasi permasalahan ini adalah asam galat dan propil galat. Dalam penelitian ini, dilakukan pengujian aktivitas asam galat dan propil galat dalam menginhibisi pertumbuhan kedua bakteri tersebut dengan menggunakan metode disk diffusion test dan menilai diameter zona hambat yang terbentuk. Terdapat 10 jenis perlakuan terhadap bakteri-bakteri ini yaitu gentamicin 10 μg sebagai kontrol positif, NaCl 0,9% dan alkohol absolut teknis 96% sebagai kontrol negatif, dan 7 jenis masing-masing senyawa asam galat dan propil galat dengan konsentrasi 16 - 1.024 mg/L. Penelitian ini dilakukan dengan 3 kali pengulangan (triplo). Hasil penelitian ini menunjukkan tidak ada zona hambat yang terbentuk (zona hambat = 0 mm) pada setiap konsentrasi asam galat dan propil galat. Uji Post-Hoc pada hubungan antara kontrol positif dan setiap konsentrasi asam galat dan propil galat diperoleh nilai p< 0,05 menunjukkan bahwa asam galat dan propil galat tidak dapat menghambat pertumbuhan Shigella dysenteriae dan Staphylococcus epidermidis secara signifikan.

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Shigella dysenteria is the etiology of shigellosis. This bacteria infect humans through the faecal-oral route and attack the gastrointestinal system. Meanwhile, Staphylococcus epidermidis is one of the most common etiologies in nosocomial infections, especially in the use of medical devices. Infection caused by these bacteria is still widely found in developing countries, one of which is Indonesia. Definitive therapy in treating diseases caused by these bacteria is the use of adequate antibiotics. However, there has been an increase in antibiotic resistance to these bacteria, so it is necessary to find new antibiotic candidates. New antibiotic candidates that have the potential to overcome this problem are gallic acid and propyl gallate.

In this study, the activity of gallic acid and propyl gallate in inhibiting the growth of both bacteria was tested by using the disk diffusion test and assessing the diameter of the inhibitory zone formed. There are 10 types of interventions, namely 10 μg gentamicin as positive control, NaCl 0.9% and absolute alcohol 96% as negative control, and 7 variety concentrations of gallic acid and propyl gallate (16 - 1.024 mg/L). This research was carried out with 3 repetitions (triplo).

The results of this study showed that there was no inhibitory zone formed (inhibitory zone = 0 mm) at any concentration of gallic acid and propyl gallate. Post-Hoc test on the comparation between positive control and each concentration of gallic and propyl gallate obtained p < 0.05 showed that gallic acid and propyl gallate could not significantly inhibit the growth of Shigella dysenteriae and Staphylococcus epidermidis."

"Penelitian yang telah dilakukan bertujuan untuk menganalisis pengaruh nitrat dan amonium serta pemberian strain Nostoc GIA13a terhadap pertumbuhan vegetatif tanaman kangkung Ipomoea aquatica Forsk. pada sistem hidroponik menggunakan larutan Hoagland. Penelitian menggunakan Rancangan Acak Lengkap RAL yang terdiri dari 5 perlakuan dengan 8 ulangan. Kelima perlakuan tersebut ialah Hoagland dengan nitrat ditambah Nostoc P1, Hoagland dengan nitrat tanpa Nostoc P2, Hoagland dengan nitrat dan amonium tanpa Nostoc P3, Hoagland dengan amonium tanpa Nostoc P4, dan Hoagland dengan amonium ditambah Nostoc P5. Pemberian Nostoc sebanyak 2 g ke dalam larutan hara dilakukan pada 0 hst dan 14 hst. Hasil Uji LSD.

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This research aims to analyze the effect of nitrate and ammonium as well as Nostoc sp. GIA13a on vegetative growth of water spinach plants Ipomoea aquatica Forsk. was carried out using a hydroponic system. Randomized Complete Design consisting of 5 treatments with eight replications was used in the study. The five treatments were Hoagland with nitrate plus Nostoc P1, Hoagland with nitrate minus Nostoc P2, Hoagland with nitrate and ammonium minus Nostoc P3, Hoagland with ammonium minus Nostoc P4, and Hoagland with ammonium plus Nostoc P5. Inoculation of 2 g of Nostoc sp. GIA13a in nutrient solution was performed at 0 hst and 14 hst. Furthermore, the LSD test results."

"Penelitian dilakukan untuk mengetahui adanya pengaruh variasi bentuk sumber nitrogen serta pemberian strain Nostoc GIA13a terhadap pertumbuhan vegetatif tanaman bayam. Proses penanaman tanaman bayam dilakukan selama 24 hari menggunakan sistem hidroponik Nutrient Film Technique NFT yang telah dimodifikasi. Perlakuan yang diberikan, yaitu medium Hoagland dengan sumber nitrogen nitrat yang ditambah strain Nostoc GIA13a P1, sumber nitrogen nitrat P2, sumber nitrogen amonium dan nitrat P3, sumber nitrogen amonium P4 dan sumber nitrogen amonium yang diberikan strain Nostoc GIA13a P5. Pemberian strain Nostoc GIA13a dilakukan pada 0 Hari Setelah Tanam HST dan 14 HST masing-masing sebanyak 2 g. Hasil uji ANOVA ? = 0,05 menunjukkan bahwa perlakuan yang diberikan memengaruhi tinggi tanaman, panjang akar, kadar klorofil total, berat basah dan berat kering tanaman bayam pada 24 HST. Perlakuan P2 menghasilkan tinggi tanaman, panjang akar, berat basah dan berat kering yang tertinggi dibandingkan dengan semua perlakuan dan didukung dengan hasil uji LSD ? = 0,01. Sementara itu, berdasarkan parameter tinggi tanaman, panjang akar, berat basah dan berat kering menunjukkan bahwa penambahan strain Nostoc GIA13a pada P1 dan P5 menunjukkan adanya kompetisi penyerapan nutrien antara tanaman bayam dan Nostoc GIA13a. Hasil pengukuran kadar klorofil menunjukkan bahwa penambahan strain Nostoc GIA13a pada perlakuan P1 dapat meningkatkan kadar klorofil tanaman bayam didukung dengan uji LSD ? = 0,01.

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The aim of the experiment was to determine the effect of nitrogen form variation and inoculation of Nostoc strain GIA13a on vegetative growth of spinach. The plants were grown in Nutrient Film Technique NFT hydroponic system for 24 days. The treatment which was given is the Hoagland nutrient solution with nitrogen source form sole nitrate with addition of Nostoc strain GIA13a P1, sole nitrate P2 , with both of nitrogen form ammonium and nitrate P3 , sole ammonium P4 and ammonium with the addition of Nostoc strain GIA13a P5 . Nostoc strain GIA13a was applicated as much as 2 g on the first day of cultivation in the hydroponic system and at 14 days after planting. The result of ANOVA test 0,05 showed that there was statistically difference between treatments on plant height, root length, chlorophyll content, wet weight and dry weight. Based on LSD test 0,01, P2 treatment showed the highest result in the following parameters, i.e. plant height, root length, wet weight and dry weight. The result from the application of Nostoc strain GIA13a to nutrient solution on P1 and P5 treatment showed that there was a competition for nutrient absorption between spinach and Nostoc strain GIA13a itself. Meanwhile, the result of chlorophyll content measurements showed that the inoculation of Nostoc strain GIA13a on P1 could increase chlorophyll content on spinach leaf, supported by LSD test 0,01."

"Bacillus sp. 140-B dan Streptomyces sp. L.3.1-DW diisolasi dari tanah dan rizosfer tanaman dari perkebunan nanas dan pisang di Provinsi Lampung. Kedua bakteri tersebut diuji kemampuannya dalam melawan patogen Fusarium oxysporum Schlecht f. sp. cubense (Foc) secara in-vitro dan in-vivo. Aplikasi Bacillus sp. 140-B dan Streptomyces sp. L.3.1-DW sebagai isolat tunggal maupun kombinasinya secara in-vivo pada tanaman pisang var. Cavendish dilakukan dalam rumah kaca selama 30 hari. Tujuan dari penelitian ini adalah untuk mengkarakterisasi dan menguji potensi Bacillus sp. 140-B dan Streptomyces sp. L.3.1-DW sebagai agen biokontrol dalam menghambat patogen Foc dan mengkaji kemampuannya untuk menghasilkan enzim ketahanan tanaman pisang. Potensi Bacillus sp. 140-B dan Streptomyces sp. L.3.1-DW sebagai agen biokontrol ditunjukkan dengan kemampuannya dalam menghambat pertumbuhan patogen Foc, sintesis enzim protease dan kitinase ekstraseluler, produksi hormon tumbuh Indole-Acetic Acid (IAA), dan produksi enzim ketahanan tanaman phenylalanine ammonia-lyase (PAL) and tyrosine ammonia lyase (TAL). Bacillus sp. 140-B dan Streptomyces sp. L.3.1-DW juga berperan sebagai plant growth-promoting rhizobacteia (PGPR), yang diindikasikan dengan peningkatan pertumbuhan tanaman pisang, di mana perlakuan Streptomyces L.3.1-DW memiliki rata-rata tinggi tanaman tertinggi dibandingkan perlakuan lainnya, dengan atau tanpa infeksi Foc. Hasil penelitian secara in-vitro dan in-vivo menunjukkan bahwa Streptomyces sp. L.3.1-DW memiliki kemampuan sebagai agen biokontrol yang lebih baik dibandingkan Bacillus sp. 140-B. Penelitian ini mengindikasikan bahwa Bacillus sp. 140-B dan Streptomyces sp. L.3.1-DW dapat digunakan sebagai alternatif untuk mengendalikan infeksi Foc.

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Bacillus sp. 140-B and Streptomyces sp. L.3.1-DW were isolated from soil and rhizosphere area of pineapple and banana plantation in Lampung Province. Those bacteria were evaluated in-vitro and in-vivo tests againts Fusarium oxysporum Schlecht f. sp. cubense (Foc). Application of Bacillus sp. 140-B and Streptomyces sp. L.3.1-DW as single isolate or in combination in banana plant var. Cavendish were tested under greenhouse conditions for 30 days.

The aims of this study were to characterize and investigate the potentials of Bacillus sp. 140-B and Streptomyces sp. L.3.1-DW as biocontrol agents to inhibit Foc pathogen and investigate their abilities to produce plant resistancy enzymes. The potentials of Bacillus sp. 140-B and Streptomyces sp. L.3.1-DW as biocontrol agents were showed by their abilities to inhibit growth of Foc pathogen, synthesize extracellular protease and chitinase enzymes, produce growth hormone, such as Indole-Acetic Acid (IAA), and produce plant resistancy enzymes, such as phenylalanine ammonia-lyase (PAL) and tyrosine ammonia lyase (TAL). Bacillus sp. 140-B and Streptomyces sp. L.3.1-DW also act as plant growth-promoting rhizobacteia (PGPR), that indicated by improvement of banana growth, in which Streptomyces L.3.1-DW caused the highest growth of banana either with or without Foc infection.

In-vitro and in-vivo tests was showed that Streptomyces sp. L.3.1-DW had better biocontrol activities compared to Bacillus sp. 140-B. This study indicated that Bacillus sp. 140-B and Streptomyces sp. L.3.1-DW could be used as alternative solutions to control Foc pathogen."