scholarly journals ISOLASI DAN KARAKTERISASI BAKTERI PENGHASIL IAA (INDOLE ACETIC ACID) DARI RHIZOSFER TANAMAN AKASIA (Acacia mangium)

2020 ◽  
Vol 3 (2) ◽  
pp. 210-219
Author(s):  
Ika Agus Rini ◽  
Indah Oktaviani ◽  
Muhammad Asril ◽  
Revi Agustin ◽  
Fina Khaerunissa Frima

IAA adalah produk paling umum dari metabolisme L-triptofan yang dapat diproduksi oleh beberapa mikroorganisme. Beberapa mikroorganisme yang memiliki potensi menghasilkan IAA adalah bakteri rhizosfer pada tanaman Leguminosae, salah satunya adalah akasia. Acacia mangium, juga dikenal sebagai akasia, adalah pohon yang tumbuh cepat. Namun, akasia adalah tanaman invasif. Tanaman akasia memiliki bintil yang merupakan hasil simbiosis akar tanaman dan bakteri. Simbiosis ini dapat mempengaruhi kesuburan tanah. Banyak potensi yang dapat digali dari bakteri tanah, khususnya di rhizosfer. Tujuan dari penelitian ini adalah untuk mengisolasi dan mengidentifikasi bakteri pada rizosfer tanaman akasia yang mampu menghasilkan IAA sebagai salah satu potensi untuk kandidat PGPR (Plant Growth Promoting Rhizobacteria). Metode yang digunakan meliputi pengambilan sampel, isolasi bakteri penghasil IAA, pemurnian bakteri, identifikasi bakteri dan uji biokimia, pembuatan kurva tumbuha bakteri, dan uji isolat bakteri pelarut fosfat. Hasil isolasi bakteri rhizosfer diperoleh sebanyak 10 isolat bakteri yang memiliki karakteristik berbeda secara morfologi.  Berdasarkan hasil identifikasi bakteri berdasarkan pewarnaan Gram, bakteri tersebut masuk ke dalam genus Bacillus dan terdapat 5 isolat bakteri yang memiliki kemampuan menghasilkan IAA dan melarutkan fosfat sehingga bakteri tersebut memiliki potensi sebagai pupuk hayati.

2021 ◽  
Vol 48 (2) ◽  
Author(s):  
Narjes H. Dashti ◽  
◽  
Nedaa Y. Ali Al-Sarraf ◽  
Vineetha M. Cherian ◽  
Magdy S. Montasser ◽  
...  

Indole acetic acid (IAA) production is one of the distinctive traits of plant growth-promoting rhizobacteria (PGPR). Ten different rhizobacterial strains were isolated from the roots of tomato crops (Solanum lycopersicum L.), grown in Kuwait, and then screened for their plant growth-promoting abilities, with emphasis on IAA production. The isolated strains were identified by 16S partial r-RNA sequencing and further characterized by conventional biochemical tests. Based on the nucleotide sequence analysis and homology of the isolates, a phylogenetic tree was constructed. The plant growth-promoting abilities of the strains were determined by testing for ammonium production, hydrogen cyanide and acid production, growth in nitrogen-free media, phosphate solubilization, and IAA production. The potential IAA PGPRs were re-applied onto the rhizosphere of green-house grown tomato plants to determine their effects on tomato growth. The results have indicated that all isolated strains were able to produce indole acetic acid even without the presence of a tryptophan precursor.


2012 ◽  
Vol 12 (51) ◽  
pp. 6170-6185
Author(s):  
A Karnwal ◽  

Plant growth-promoting rhizobacteria (PGPR) are free-living soil-borne bacteria that colonize the rhizosphere and have great importance in governing the functional property of terrestrial ecosystems. In this study, rhizospheric bacteria were isolated from maize and wheat and screened for their plant growth promoting activities. These isolates were identified as Pseudomonas , Bacillus , Azospirillum and Azotobacter species. All isolates were tested for their indole acetic acid (IAA) production ability. All isolates produce the varying amount s o f IAA ranging from 0.6- 2.7 μg/ml. The highest concentration of IAA was produced by bacterial strain Bacillus subtilis AK31. A series of growth pouch and pot experiments were conducted to study the effect of bacterial inoculants on the growth of maize and wheat. It was concluded that IAA plays a key role i n the growth promotion of roots in maize and wheat in growth pouch study. In maize, isolate AK1, AK21, AK31 and AK8 showed high indole acetic acid (6.86, 7.11, 7.11 and 7.36 pmol/ml, respectively) and root elongation activity ( 4.10, 5.00, 5.00 and 3.80 cm, respectively) after 96h of growth. In wheat, bacterial strains AK31, AK2, AK14, AK32 and AK15 showed high IAA ( 6.59, 5.66, 5.35, 7.53 and 5.66 pmol/ml, respectively) and root elongation ( 6.07, 4.00, 5.20, 6.90 and 5.20 cm, respectively) activity after 96h of growth. In pot experiments, Bacillus sp. AK21, Bacillus subtilis AK31, Azotobacter diazotrophicus AK14, Microbacterium sp. AK19 and Pseudomonas fluorescens AK32 showed effective results in term s of increase in root and shoot dry weight in maize (123, 130, 121, 120, 124g and 116, 126, 116, 114, 120g/pot, respectively) and wheat (130, 135, 125, 118, 140g and 105, 106, 110, 102, 110g/pot, respectively), in comparison to controls of maize and wheat crops. Thus, it might be concluded that PGPR strains AK21, AK31, AK14, AK19 and AK32 could be used as crop- enhancer and bio- fertilizer for production of maize and wheat .


1996 ◽  
Vol 42 (3) ◽  
pp. 279-283 ◽  
Author(s):  
T. C. Noel ◽  
C. Sheng ◽  
C. K. Yost ◽  
R. P. Pharis ◽  
M. F. Hynes

Early seedling root growth of the nonlegumes canola (Brassica campestris cv. Tobin, Brassica napus cv. Westar) and lettuce (Lactuca saliva cv. Grand Rapids) was significantly promoted by inoculation of seeds with certain strains of Rhizobium leguminosarum, including nitrogen- and nonnitrogen-fixing derivatives under gnotobiotic conditions. The growfh-promotive effect appears to be direct, with possible involvement of the plant growth regulators indole-3-acetic acid and cytokinin. Auxotrophic Rhizobium mutants requiring tryptophan or adenosine (precursors for indole-3-acetic acid and cytokinin synthesis, respectively) did not promote growth to the extent of the parent strain. The findings of this study demonstrate a new facet of the Rhizobium–plant relationship and that Rhizobium leguminosarum can be considered a plant growth-promoting rhizobacterium (PGPR).Key words: Rhizobium, plant growth-promoting rhizobacteria, PGPR, indole-3-acetic acid, cytokinin, roots, auxotrophic mutants.


2016 ◽  
Vol 3 (1) ◽  
pp. 105-113 ◽  
Author(s):  
Mohammad Mosharraf Hossain ◽  
Keshob Chandra Das ◽  
Sabina Yesmin ◽  
Syfullah Shahriar

Plant growth promoting rhizobacteria (PGPR) are beneficial bacteria that colonize plant roots and enhance plant growth by a wide variety of mechanisms. Ten isolates of bacteria designated as SS01, SS02, SS03, SS04, SS05, SS06, SS07, SS08, SS09 and SS10 were successfully isolated and morphologically and biochemically characterized. Subsequently to investigate the effect of PGPR isolates on the growth of chickpea, a pot culture experiment was conducted in 2013 at National Institute Biotechnology, Bangladesh net house. Prior to seeds grown in plastic pots, seeds were treated with PGPR isolates and seedlings were harvested after 21 days of inoculation. All the isolates were gram negative in reaction, catalase positive, produced indole acetic acid (IAA) as well as performed phosphate solubilization, able to degrade cellulose and have the adaptability in wide range of temperature and showed positive growth pattern in medium. Most of isolates resulted in a significant increasing of shoot length, root length and dry matter production of shoot and root of chickpea seedlings. Application of PGPR isolates significantly improves the percentage of seed germination under saline conditions. The present study, therefore suggested that the use of PGPR isolates SS04, SS10 and SS08 as inoculants biofertilizers might be beneficial for chickpea cultivation in saline conditionRes. Agric., Livest. Fish.3(1): 105-113, April 2016


Author(s):  
Caroline F. Ajilogba ◽  
Olubukola O. Babalola ◽  
Patrick Adebola ◽  
Rasheed Adeleke

AbstractBambara groundnut, an underutilized crop has been proved to be an indigenous crop in Africa with the potential for food security. The rhizosphere of Bambara groundnut like other legumes contains several important bacteria that have not been explored for their plant growth-promoting properties. The aim of this research was to determine the potentials of rhizobacteria from Bambara groundnut soil samples as either biofertilizer or biocontrol agents or both to help provide sustainable agriculture in Africa and globally. Analyses of Bambara groundnut rhizospheric soil samples included chemical analysis such as nitrogen content analysis using extractable inorganic nitrogen method as well as cation exchangeable capacity using ammonium acetate method. Plant growth-promoting properties of isolated rhizobacteria tested include indole acetic acid, hydrogen cyanide, phosphate solubilization, 1-aminocyclopropane-1-carboxylate and ammonia production activities using standard methods. In addition, antifungal assay dual culture method was used to analyze the biocontrol properties of the isolates. Phylogenetic analysis using 16S rRNA was also carried out on the isolates. Isolated rhizobacteria from bambara groundnut rhizosphere were cultured. All the isolates were able to produce ammonia and 1-aminocyclopropane-1-carboxylate while 4.65%, 12.28% and 27.91% produced Hydrogen cyanide, Indole acetic acid and solubilized phosphate respectively, making them important targets as biocontrol and biofertilizer agents. The growth of Fusarium graminearum was suppressed in vitro by 6.98% of the isolates. Plant growth promoting activities of rhizobacteria from bambara groundnut rhizosphere reveals that it has great potentials in food security as biofertilizer and biocontrol agent against fungal and bacterial pathogens.


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