scholarly journals Screening of beneficial bacteria associated with Calophyllum brasiliense Cambess so as to develop microbial inoculants for agriculture

Plant Omics ◽  
2019 ◽  
pp. 93-101
Author(s):  
Bruno Rogério de Souza ◽  
Lílian Estrela Borges Baldotto ◽  
Alessandra Monteiro de Paula ◽  
Fabrício Souza Campos ◽  
Klever Cristiano Silveira ◽  
...  

Beneficial bacteria belong to a group of microorganisms that are able to enhance plant growth by several mechanisms. In this study, phosphorus and zinc solubilizing, nitrogen-fixing and indole acetic acid (IAA) producing bacteria associated with C. brasiliensis were screened to develop microbial inoculants (MI) for use in agriculture. Characterization and identification of screened bacteria were also performed. A total of thirty-one nitrogen-fixing bacteria isolates were obtained, of which 28 showed the ability to solubilize phosphorus and 25 to solubilize zinc. The isolate AP-JNFb-3-2, belonging to the genus Pseudomonas, presented the highest value of solubilized phosphorus (100.4 µg mL-1). The isolates AP-JNFb-3-2 and RHI-JMVL-3-1, associated with the genera Pseudomonas and Enterobacter, respectively, showed the highest values for zinc solubilization (147.8 and 147.7 µg mL-1). Isolate RO-LGI.P-3-2, belonging to the genus Pseudomonas, was the most promising for IAA production (0.52 µg mL-1). The results obtained showed the presence of a large diversity of beneficial bacteria associated with C. brasiliensis, which may be explored as MI in agriculture.

2019 ◽  
Vol 41 (4) ◽  
Author(s):  
Nguyen Ngoc Lan ◽  
Vu Van Dzung ◽  
Nguyen Thi Kim Lien ◽  
Nguyen Kim Thoa ◽  
Do Huu Nghi ◽  
...  

Beneficial plant-growth-promoting bacteria (PGPB) have been reasonably applied to rescue crucial issue for agriculture by salinity soil. Observed most of PGPB was found in endophyte, rhizosphere and soil. Indole acetic acid (IAA)-producing bacteria could naturally stimulate and facilitate plant growth. The knowledge of IAA production and content of bacteria resident in the marine environment has been typically insufficient and limited to date. In recent years, unwarrantable intrusions of sea water have been enlarged in the Mekong River Delta of Vietnam, threatening productive rice fields, local fruits, and cash crops. Therefore, finding PGPB in the coastal regions in the Mekong River Delta as a creative resource for sustainable agriculture is necessary and is a prompt challenge. In this study, IAA-producing bacteria from coastal regions of Ben Tre and Tra Vinh Provinces were isolated and adequately identified. Out of 202 bacterial isolates, 10 isolates showed the possible ability to produce IAA from L-tryptophan. These 10 isolates were objectively evaluated the capacity to produce IAA under 5% (w/v) NaCl in King B and marine broths. The results revealed that IAA production decreased in 5% NaCl, even though bacterial growth increased. These 10 IAA-producing bacteria were classified at the species level, Marinobacter hydrocarbonoclasticus, M. pelagius, M. daepoensis, and Mameliella phaeodactyli by 16S rRNA gene analysis. The most IAA producer in King’s B broth, the isolate C7, was investigated in more detail. The isolate C7 produced the maximum IAA amount (192.2 ± 1.14 µg/ml) under the presence of 20 g/l yeast extract, 2 g/l of L-tryptophan and 1% NaCl. The isolate C7 was able to grow at 1–17% (w/v) NaCl (optimum, 4%), but not in the absence of NaCl, indicating it is a moderate halophilic bacteria. This study highlighted the considerable ability to produce IAA of marine bacteria, which could be thoughtfully considered to use naturally as biofertilizers to promote plant growth in saline intrusion lands. 


2020 ◽  
Vol 10 (1) ◽  
pp. 21
Author(s):  
Agustina Monalisa Tangapo

Potensi Bakteri Endofit Ubi Jalar (Ipomoea batatas L.) dalam Menghasilkan Hormon Indole Acetic Acid (IAA) dengan Penambahan L-triptofan(Potential of endophytic bacteria of sweet potato (Ipomoea batatas L.) in producing Indole Acetic Acid (IAA) with the addition of L-tryptophan) Agustina Monalisa TangapoProgram Studi Biologi FMIPA Universitas Sam RatulangiJl. Kampus Unsrat, Manado 95115*Email korespondensi:[email protected] (Article History: Received 5-01-2019; Revised 15-01-2020; Accepted 05-02-2020) ABSTRAKAsosiasi bakteri-tanaman, dapat mempengaruhi produktivitas tanaman secara langsung dan tidak langsung. Secara langsung, salah satunya yaitu bakteri dapat memproduksi dan menyekresikan zat pengatur tumbuh indole-3-acetic acid (IAA, auksin). Penelitian ini bertujuan untuk menguji kemampuan bakteri endofit ubi jalar dalam menghasilkan IAA. Metode analisis IAA dilakukan dengan metode kolorimetri. Analisis produksi IAA dilakukan dengan penambahan dan tanpa penambahan L-triptofan. Hasil penelitian menunjukkan bahwa tanpa penambahan L-triptofan, diperoleh sejumlah 19 jenis yang menghasilkan IAA dengan kisaran konsentrasi 0,29-7,21 mg/L. Dengan penambahan L-triptofan, jumlah jenis positif dan konsentrasi IAA yang dihasilkan meningkat signifikan. Jumlah jenis positif 20 jenis (91%) dan konsentrasi IAA yang dihasilkan mencapai kisaran 0,96-115,63 mg/L.Kata kunci: bakteri endofit; IAA; ubi jalar; L-triptofan ABSTRACTPlant-bacteria associations, can promote plant growth by both direct and indirect mechanisms. One of direct mechanisms is that bacteria can produce and secrete indole-3-acetic acid (IAA, auxin) growth regulators. This study aims to examine the ability of sweet potato endophytic bacteria to produce IAA. The detection of IAA production was conducted by colorimetric technique. IAA production analysis was carried out with addition and without addition of L-tryptophan. Without the addition of L-tryptophan, a total of 19 species produced IAA with a concentration range of 0.29-7.21 mg/L. With the addition of L-tryptophan, the number of positive species and the concentration of IAA produced increased significantly. The number of positive species was 20 species (91%) and the concentration of IAA produced reached a range of 0.96-115.63 mg/L.Keywords: endophytes bacterial; IAA; sweet potato; L-tryptophan


2021 ◽  
Vol 23 (06) ◽  
pp. 1294-1312
Author(s):  
Yamini P ◽  
◽  
Reshmi Gopalakrishnan ◽  
Sanjay Prasad S ◽  
Karkuvelraja R ◽  
...  

Indole acetic acid (IAA) production is a major property of rhizosphere bacteria that stimulates and facilitates plant growth. The present work deals with the isolation, characterization, and identification of indole acetic acid-producing bacteria from the rhizospheric soil. Out of four organisms isolated from serial dilution, Sample-2 confirmed thick bands of IAA production by TLC analysis. 16s rRNA analysis showed the isolated organism was found to be Pseudomonas fluorescence with a similarity of 88%. The isolated organism treat plants showed increased shoot and root length in plant growth analysis. In conclusion, the isolated IAA-producing bacteria can be used as efficient biofertilizer inoculants to promote plant growth.


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.


2019 ◽  
Vol 41 (4) ◽  
Author(s):  
Nguyen Ngoc Lan ◽  
Vu Van Dzung ◽  
Nguyen Thi Kim Lien ◽  
Nguyen Kim Thoa ◽  
Do Huu Nghi ◽  
...  

Beneficial plant-growth-promoting bacteria (PGPB) have been reasonably applied to rescue crucial issue for agriculture by salinity soil. Observed most of PGPB was found in endophyte, rhizosphere and soil. Indole acetic acid (IAA)-producing bacteria could naturally stimulate and facilitate plant growth. The knowledge of IAA production and content of bacteria resident in the marine environment has been typically insufficient and limited to date. In recent years, unwarrantable intrusions of sea water have been enlarged in the Mekong River Delta of Vietnam, threatening productive rice fields, local fruits, and cash crops. Therefore, finding PGPB in the coastal regions in the Mekong River Delta as a creative resource for sustainable agriculture is necessary and is a prompt challenge. In this study, IAA-producing bacteria from coastal regions of Ben Tre and Tra Vinh Provinces were isolated and adequately identified. Out of 202 bacterial isolates, 10 isolates showed the possible ability to produce IAA from L-tryptophan. These 10 isolates were objectively evaluated the capacity to produce IAA under 5% (w/v) NaCl in King B and marine broths. The results revealed that IAA production decreased in 5% NaCl, even though bacterial growth increased. These 10 IAA-producing bacteria were classified at the species level, Marinobacter hydrocarbonoclasticus, M. pelagius, M. daepoensis, and Mameliella phaeodactyli by 16S rRNA gene analysis. The most IAA producer in King’s B broth, the isolate C7, was investigated in more detail. The isolate C7 produced the maximum IAA amount (192.2 ± 1.14 µg/ml) under the presence of 20 g/l yeast extract, 2 g/l of L-tryptophan and 1% NaCl. The isolate C7 was able to grow at 1–17% (w/v) NaCl (optimum, 4%), but not in the absence of NaCl, indicating it is a moderate halophilic bacteria. This study highlighted the considerable ability to produce IAA of marine bacteria, which could be thoughtfully considered to use naturally as biofertilizers to promote plant growth in saline intrusion lands. 


Soil Systems ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 26
Author(s):  
Rihab Djebaili ◽  
Marika Pellegrini ◽  
Massimiliano Rossi ◽  
Cinzia Forni ◽  
Maria Smati ◽  
...  

This study aimed to characterize the halotolerant capability, in vitro, of selected actinomycetes strains and to evaluate their competence in promoting halo stress tolerance in durum wheat in a greenhouse experiment. Fourteen isolates were tested for phosphate solubilization, indole acetic acid, hydrocyanic acid, and ammonia production under different salt concentrations (i.e., 0, 0.25, 0.5, 0.75, 1, 1.25, and 1.5 M NaCl). The presence of 1-aminocyclopropane-1-carboxylate deaminase activity was also investigated. Salinity tolerance was evaluated in durum wheat through plant growth and development parameters: shoot and root length, dry and ash-free dry weight, and the total chlorophyll content, as well as proline accumulation. In vitro assays have shown that the strains can solubilize inorganic phosphate and produce indole acetic acid, hydrocyanic acid, and ammonia under different salt concentrations. Most of the strains (86%) had 1-aminocyclopropane-1-carboxylate deaminase activity, with significant amounts of α-ketobutyric acid. In the greenhouse experiment, inoculation with actinomycetes strains improved the morpho-biochemical parameters of durum wheat plants, which also recorded significantly higher content of chlorophylls and proline than those uninoculated, both under normal and stressed conditions. Our results suggest that inoculation of halotolerant actinomycetes can mitigate the negative effects of salt stress and allow normal growth and development of durum wheat plants.


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