Ultrastructure of interaction in alginate beads between the microalgaChlorella vulgariswith its natural associative bacteriumPhyllobacterium myrsinacearumand with the plant growth-promoting bacteriumAzospirillum brasilense

2001 ◽  
Vol 47 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Vladimir K Lebsky ◽  
Luz E Gonzalez-Bashan ◽  
Yoav Bashan
Keyword(s):  
Wastewater Treatment ◽  
Plant Growth ◽  
Azospirillum Brasilense ◽  
Bacterial Species ◽  
Alginate Beads ◽  
Transmission Electron ◽  
Associative Bacteria ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Treatment Water

Chlorella vulgaris, a microalga often used in wastewater treatment, was coimmobilized and coincubated either with the plant growth-promoting bacterium Azospirillum brasilense, or with its natural associative bacterium Phyllobacterium myrsinacearum, in alginate beads designed for advanced wastewater treatment. Interactions between the microalga and each of the bacterial species were followed using transmission electron microscopy for 10 days. Initially, most of the small cavities within the beads were colonized by microcolonies of only one microorganism, regardless of the bacterial species cocultured with the microalga. Subsequently, the bacterial and microalgal microcolonies merged to form large, mixed colonies within the cavities. At this stage, the effect of bacterial association with the microalga differed depending on the bacterium present. Though the microalga entered a senescence phase in the presence of P. myrsinacearum, it remained in a growth phase in the presence of A. brasilense. This study suggests that there are commensal interactions between the microalga and the two plant associative bacteria, and that with time the bacterial species determined whether the outcome for the microalga is senescence or continuous multiplication.Key words: Azospirillum, Chlorella, Phyllobacterium, wastewater treatment, water bioremediation.

scholarly journals Increased Growth of the Microalga Chlorella vulgariswhen Coimmobilized and Cocultured in Alginate Beads with the Plant-Growth-Promoting Bacterium Azospirillum brasilense

2000 ◽  
Vol 66 (4) ◽  
pp. 1527-1531 ◽  
Author(s):  
Luz E. Gonzalez ◽  
Yoav Bashan
Keyword(s):  
Plant Growth ◽  
Azospirillum Brasilense ◽  
Effective Means ◽  
Alginate Beads ◽  
Plant Growth Promoting Bacteria ◽  
Fresh Weight ◽  
Microalgal Culture ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Indole 3 Acetic Acid

ABSTRACT Coimmobilization of the freshwater microalga Chlorella vulgaris and the plant-growth-promoting bacteriumAzospirillum brasilense in small alginate beads resulted in a significantly increased growth of the microalga. Dry and fresh weight, total number of cells, size of the microalgal clusters (colonies) within the bead, number of microalgal cells per cluster, and the levels of microalgal pigments significantly increased. Light microscopy revealed that both microorganisms colonized the same cavities inside the beads, though the microalgae tended to concentrate in the more aerated periphery while the bacteria colonized the entire bead. The effect of indole-3-acetic acid addition to microalgal culture prior to immobilization of microorganisms in alginate beads partially imitated the effect of A. brasilense. We propose that coimmobilization of microalgae and plant-growth-promoting bacteria is an effective means of increasing microalgal populations within confined environments.

scholarly journals Protection of Tomato Seedlings against Infection by Pseudomonas syringae pv. Tomato by Using the Plant Growth-Promoting Bacterium Azospirillum brasilense

2002 ◽  
Vol 68 (6) ◽  
pp. 2637-2643 ◽  
Author(s):  
Yoav Bashan ◽  
Luz E. de-Bashan
Keyword(s):  
Plant Growth ◽  
Pseudomonas Syringae ◽  
Azospirillum Brasilense ◽  
Dry Weight ◽  
Tomato Plants ◽  
Bacterial Speck ◽  
Plant Growth Promoting ◽  
Bacterial Speck Disease ◽  
Growth Promoting ◽  
Mist Chamber

ABSTRACT Pseudomonas syringae pv. tomato, the causal agent of bacterial speck of tomato, and the plant growth-promoting bacterium Azospirillum brasilense were inoculated onto tomato plants, either alone, as a mixed culture, or consecutively. The population dynamics in the rhizosphere and foliage, the development of bacterial speck disease, and their effects on plant growth were monitored. When inoculated onto separate plants, the A. brasilense population in the rhizosphere of tomato plants was 2 orders of magnitude greater than the population of P. syringae pv. tomato (107 versus 105 CFU/g [dry weight] of root). Under mist chamber conditions, the leaf population of P. syringae pv. tomato was 1 order of magnitude greater than that of A. brasilense (107 versus 106 CFU/g [dry weight] of leaf). Inoculation of seeds with a mixed culture of the two bacterial strains resulted in a reduction of the pathogen population in the rhizosphere, an increase in the A. brasilense population, the prevention of bacterial speck disease development, and improved plant growth. Inoculation of leaves with the mixed bacterial culture under mist conditions significantly reduced the P. syringae pv. tomato population and significantly decreased disease severity. Challenge with P. syringae pv. tomato after A. brasilense was established in the leaves further reduced both the population of P. syringae pv. tomato and disease severity and significantly enhanced plant development. Both bacteria maintained a large population in the rhizosphere for 45 days when each was inoculated separately onto tomato seeds (105 to 106 CFU/g [dry weight] of root). However, P. syringae pv. tomato did not survive in the rhizosphere in the presence of A. brasilense. Foliar inoculation of A. brasilense after P. syringae pv. tomato was established on the leaves did not alleviate bacterial speck disease, and A. brasilense did not survive well in the phyllosphere under these conditions, even in a mist chamber. Several applications of a low concentration of buffered malic acid significantly enhanced the leaf population of A. brasilense (>108 CFU/g [dry weight] of leaf), decreased the population of P. syringae pv. tomato to almost undetectable levels, almost eliminated disease development, and improved plant growth to the level of uninoculated healthy control plants. Based on our results, we propose that A. brasilense be used in prevention programs to combat the foliar bacterial speck disease caused by P. syringae pv. tomato.

Promoter-trap identification of wheat seed extract-induced genes in the plant-growth-promoting rhizobacterium Azospirillum brasilense Sp245

Microbiology ◽  
2007 ◽  
Vol 153 (10) ◽  
pp. 3608-3622 ◽  
Author(s):  
Joël F. Pothier ◽  
Florence Wisniewski-Dyé ◽  
Michèle Weiss-Gayet ◽  
Yvan Moënne-Loccoz ◽  
Claire Prigent-Combaret
Keyword(s):  
Plant Growth ◽  
Azospirillum Brasilense ◽  
Seed Extract ◽  
Wheat Seed ◽  
Promoter Trap ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Induced Genes

Inoculation with the Plant-Growth-Promoting Rhizobacterium Azospirillum brasilense Causes Little Disturbance in the Rhizosphere and Rhizoplane of Maize (Zea mays)

2005 ◽  
Vol 50 (2) ◽  
pp. 277-288 ◽  
Author(s):  
Yoav Herschkovitz ◽  
Anat Lerner ◽  
Yaacov Davidov ◽  
Michael Rothballer ◽  
Anton Hartmann ◽  
...  
Keyword(s):  
Zea Mays ◽  
Plant Growth ◽  
Azospirillum Brasilense ◽  
Plant Growth Promoting ◽  
Growth Promoting

scholarly journals Effect of Azospirillum brasilense and mycorrhizal soil fungi on topinambur grown in a greenhouse

2021 ◽  
Vol 8 (4) ◽  
pp. 104-110
Author(s):  
Di Barbaro Gabriela ◽  
Andrada Horacio ◽  
Batallan Morales Silvana ◽  
Espeche Acosta Eliana ◽  
Rizo Melisa ◽  
...  
Keyword(s):  
Plant Growth ◽  
Mycorrhizal Fungi ◽  
Azospirillum Brasilense ◽  
Soil Fungi ◽  
Jerusalem Artichoke ◽  
Promoting Effect ◽  
Greenhouse Production ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
The Moment

To determine the effect of Azospirillum brasilense and soil mycorrhizal fungi on the nutrition of the Jerusalem artichoke crop (Helianthus tuberosus L.), evaluations of agronomic parameters and the health status of the plants were carried out, under greenhouse conditions. The tests were carried out, at the moment of the implantation of the culture: the tubers were inoculated with A. brasilense and with native mycorrhizal fungi, generating four treatments including the control and the co-inoculation of the consortium of the microorganisms under study (T0: control or control without inoculation; T1: inoculation with native A. brasilense; T2: inoculation with native mycorrhizal fungi and T3: joint inoculation with A. brasilense and native mycorrhizal fungi. The results indicate that co-inoculation with A. brasilense and with native mycorrhizal fungi increased plant growth in height, leaf area, biomass, dry matter, and yields significantly in greenhouse production. It was determined that the application of the selected microorganisms has a plant growth-promoting effect, increasing the productivity of cultivated topinambur in the greenhouse

scholarly journals Potential Role of Rice Plant Growth Promoting Phylloplane and Rhizospheric Bacteria in Controlling Xanthomonas oryzae pv. oryzae

2021 ◽  
Author(s):  
Md. Mahfujur Rahman ◽  
Md. Mostafa Masud ◽  
Muhammad Iqbal Hossain ◽  
Nur-E-Tajkia Islam ◽  
Md. Zahangir Alam ◽  
...  
Keyword(s):  
Plant Growth ◽  
Rice Plant ◽  
Bacterial Species ◽  
Management Approach ◽  
Field Efficacy ◽  
Pcr Products ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Develop Environment

Rice is an important cereal worldwide and it occupies the top position among the cereals in Bangladesh. Rice plant suffers from around 32 diseases of which ten are major in Bangladesh at present. Among the diseases, Bacterial Blight (BB) caused by X. oryzae pv. oryzae (Xoo) considered as a most destructive disease occurs in both rainfed and irrigated seasons of Bangladesh. BB causes considerable yield loss varies from 30 to 50% depending on the outbreak. It is also an important disease in most of the South and Southeast Asian countries. To develop environment-friendly sustainable management approach against BB of rice, in total sixty three plant growth promoting bacteria were identified from rice phylloplane and rhizosphere that are antagonistic to X. oryzae pv. oryzae during boro and aman seasons 2018 and 2019.These bacterial species inhibited the growth of X. oryzae pv. oryzae in vitro by 20.83 to 76.19%. These bacterial isolates were identified by sequencing of PCR products of 16SrDNA belonging to the genera mostly Pseudomonas, Bacillus and Serratia. Out of these bacterial species, 48 bacterial species were found as positive for IAA production, all 63 bacterial species were found positive for siderophore production and 48 were found capable to solubilize insoluble phosphate. Based on growth inhibition of X. oryzae pv. oryzae in in vitro, thirty two bacterial species were selected for plant growth promotion assessment and evaluation of net house and field efficacy in controlling BB of rice. These bacterial species were formulated using talcum powder which was viable for at least three months post formulation. Assessment of plant growth promoting determinants revealed that all 32 bacterial species identified in this study enhance the growth of rice plants as measured by root and shoot length and and reduced the BB severity in susceptible rice cultivar significantly as compared with untreated control.

scholarly journals Using two plant growth promoting bacteria to sustainably reduce the drought-induced loss in Triticum aestivum yield

2020 ◽  
Vol 12 (2) ◽  
pp. 433-446
Author(s):  
El-Anwar OSMAN ◽  
Wedad A. KASIM ◽  
Nabil A. OMAR ◽  
Samar E. SALAMA
Keyword(s):  
Amino Acids ◽  
Drought Stress ◽  
Plant Growth ◽  
Free Amino Acids ◽  
Free Amino ◽  
Azospirillum Brasilense ◽  
Stenotrophomonas Maltophilia ◽  
Plant Growth Promoting ◽  
Total Free Amino Acids ◽  
Growth Promoting

In a greenhouse experiment, the inoculated and uninoculated grains with Azospirillum brasilense NO40 or Stenotrophomonas maltophilia were sown in unsterilized sandy soil and watered normally till the 8th day. Thereafter, the drought stress was initiated by watering pots once every 10 days while the unstressed pots were irrigated normally once every 5 days. Samples of spikes and dry grains were collected after 120 days from sowing. The results indicated that the inoculated-drought-stressed plants maintained significantly higher values of all of the measured yield parameters, where the yielded grains had higher amounts of the direct reducing sugars, sucrose, starch; lower contents of total soluble proteins and the total free amino acids, and altered protein patterns compared to those of the uninoculated-drought-stressed plants. SDS-PAGE of the yielded grains showed that drought led to the appearance of some newly synthesized stress protein bands and disappearance of others. Inoculation with PGPB resulted in the re-appearance of some of the disappearing bands and the synthesis of new others. Meanwhile, wheat inoculation under normal conditions resulted in significantly promoted grain yields with higher contents of carbohydrates, total soluble proteins and total free amino acids than that of the uninoculated control. It has been proved that treating wheat plants with the PEG-tolerant Azospirillum brasilense NO40 or Stenotrophomonas maltophilia that were compatible with the systems into which they were introduced and possess multiple plant growth promoting traits, can be an efficient strategy to enhance wheat growth and productivity, not only under normal conditions, but also under drought stress.

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