scholarly journals Bacterias endófitas de la raíz en líneas de maíces tolerantes y susceptibles a sequía

2018 ◽  
Vol 36 (1) ◽  
Author(s):  
Alma Sánchez-Bautista ◽  
Carlos De León-García de Alba ◽  
Sergio Aranda-Ocampo ◽  
Emma Zavaleta-Mejía ◽  
Cristian Nava-Díaz ◽  
...  
Keyword(s):  
Zea Mays ◽  
Bacillus Subtilis ◽  
Bacillus Megaterium ◽  
Sinorhizobium Meliloti ◽  
Bacillus Firmus ◽  
Burkholderia Gladioli ◽  
Acinetobacter Soli

<p>El maíz (<em>Zea mays</em>) ocupa el segundo lugar como alimento en el mundo y la sequía limita su productividad. Las plantas albergan bacterias endófitas que influyen en la sanidad y tolerancia a la sequía. El objetivo de esta investigación fue estimar la densidad y diversidad de las bacterias endófitas cultivables de la raíz en siete líneas homocigóticas de maíces tolerantes y siete susceptibles a sequía en tres localidades de México durante tres ciclos del cultivo. La densidad y diversidad de las poblaciones bacterianas se evaluó mediante conteo directo en placas y se identificaron por PCR. Los resultados identificaron tres grupos de bacterias endófitas: 1) altamente frecuentes (<em>Bacillus subtilis</em>, <em>Bacillus megaterium</em> y <em>Pseudomonas geniculata)</em>, 2)<em> </em>frecuentes (<em>Bacillus firmus</em>, <em>Pseudomonas hibiscola</em> y <em>Sinorhizobium meliloti)</em> y 3) baja frecuencia (<em>Acinetobacter soli, Stenotrophomonas maltophila </em>y<em> Burkholderia gladioli</em>.  El análisis de varianza (ANOVA) mostró diferencias significativas (p?0,05)<strong> </strong>en la densidad (<sub>Log10 </sub>UFC g<sup>-1</sup> de raíz) de población por localidad, ciclo de cultivo, días después de siembra y líneas de maíz. La densidad de <em>Bacillus subtilis, Pseudomonas hibiscola </em>en la localidad de El<em> </em>Batán<em> y Bacillus megaterium, Sinorhizobium meliloti</em> en Tlaltizapán, fueron significativamente mayores en las líneas de maíz tolerantes que en las susceptibles a sequía. </p>

scholarly journals Inducción de resistencia a Puccinia sorghi y complejo mancha de asfalto (Phyllachora maydis y otros) en maíz (Zea mays)

2018 ◽  
Vol 37 (1) ◽  
Author(s):  
Federico Díaz-Morales ◽  
Carlos De León-García De Alba ◽  
Cristian Nava-Díaz ◽  
María Del Carmen Mendoza-Castillo
Keyword(s):  
Zea Mays ◽  
Bacillus Subtilis ◽  
Bacillus Firmus ◽  
Puccinia Sorghi ◽  
La Mancha

Para demostrar la eficiencia de productos inductores de la resistencia a enfermedades en maíz, en 2016 y 2017 se establecieron ensayos en el Campo Experimental de la Universidad Autónoma del Estado de México, Campus Toluca, con el híbrido de maíz comercial BG1384W, donde se estudió la eficiencia de seis agroquímicos como inductores de resistencia, incluyendo Fosetil-Al, Acibenzolar-S-metil, Bacillus subtilis, Tebuconazole + Trifloxystrobin, Proteína Harpin y Clotianidin + Bacillus firmus, para controlar la roya común (Puccinia sorghi Schw.) y el complejo de la mancha de asfalto (Phyllachora maydis Maubl. y otros), con dos formas de aplicación (al suelo y foliar) y tres dosis (comercial recomendada, mitad de la recomendada y recomendada más 50%) para cada agroquímico. Se registraron datos agronómicos en un ensayo de rendimiento y la severidad de las mencionadas enfermedades. En 2016, la severidad no fue afectada por ninguno de los agroquímicos, aunque se incrementó el rendimiento con las aplicaciones de Fosetil-Al y Acibenzolar-S-metil. En 2017, Bacillus subtilis disminuyó la severidad de la roya, mientras que Fosetil-Al redujo la severidad del complejo mancha de asfalto, pero mostró el rendimiento más bajo.

Productivity of forage grasses affected by microbial preparations in the Vologda region

2021 ◽  
pp. 21-25
Author(s):  
А.В. Платонов ◽  
И.И. Рассохина ◽  
Л.В. Сухарева ◽  
Г.Ю. Лаптев ◽  
В.Н. Большаков
Keyword(s):  
Bacillus Subtilis ◽  
Bacillus Megaterium ◽  
Nutritional Value ◽  
Crop Productivity ◽  
Exchange Energy ◽  
Lactobacillus Buchneri ◽  
Green Mass ◽  
Digestible Protein ◽  
Green Mass Yield ◽  
Feed Unit

Использование микробных препаратов — перспективный путь повышения продуктивности сельскохозяйственных растений. В статье приведены результаты изучения влияния биопрепаратов, созданных на основе живых штаммов микроорганизмов Bacillus subtilis («Натурост»), Lactobacillus buchneri («Натурост-Актив») и Bacillus megaterium («Натурост-М»), на продуктивность и питательную ценность райграса однолетнего и клеверо-тимофеечной смеси. Исследование проводили в мелкоделяночном полевом опыте во ФГБУН ВолНЦ РАН (Вологодская область) в 2019–2020 годах. Под влиянием обработки биопрепаратами выход зелёной массы райграса возрастал на 13,7–65,5% в зависимости от опытного варианта. Продуктивность травосмеси клевера и тимофеевки увеличилась на 13,1–46,6% в зависимости от используемого биопрепарата, укоса и года исследования. Оценка питательной ценности райграса показала, что обработка биопрепаратами способствовала повышению содержания кормовых единиц в сухом веществе на 6,5%, также несколько увеличилось содержание обменной энергии, сырого и переваримого протеина, сахаров и жиров. Питательная ценность клеверо-тимофеечной смеси по содержанию кормовых единиц под влиянием биопрепаратов увеличилась на 15%. В опытах с райграсом бόльшая продуктивность зелёной массы получена при использовании препарата «Натурост-Актив», в опытах с клеверо-тимофеечной смесью отмечена бόльшая эффективность препарата «Натурост». В исследованиях 2019 года повышение питательной ценности зелёной массы у обеих культур в большей степени происходило под влиянием препарата, созданного на основе бактерий Bacillus megaterium. В 2020 году более выраженное увеличение содержания кормовых единиц, обменной энергии, сырого протеина, переваримого протеина и жиров происходило при внесении препарата на основе бактерий Bacillus subtilis. Microbial preparations were shown to be promising when increasing crop productivity. This article reports on the effect of biopreparations containing living strains of Bacillus subtilis (“Naturost”), Lactobacillus buchneri (“Naturost-Aktiv”) and Bacillus megaterium (“Naturost-M”) on the yield and nutritional value of annual ryegrass and clover-timothy mixture. Microplot field trial took place in 2019–2020. Biopreparations improved green mass yield of ryegrass by 13.7–65.5%. The productivity of the clover-timothy mixture increased by 13.1–46.6% affected by biopreparations, cut and year. Treatment with biopreparations increased feed unit content by 6.5% in dry matter (DM) as well as exchange energy, crude and digestible protein, sugar and fat. Biopreparations improved feed unit content of the clover-timothy mixture by 15%. Ryegrass produced the highest yield of green mass under “Naturost-Aktiv” application, while “Naturost” was more effective for the clover-timothy mixture. In 2019 Bacillus megaterium had the best effect on the nutritional value of crop green mass. The contents of feed units, exchange energy, crude and digestible proteins as well as fat grew significantly after Bacillus subtilis application in 2020.

scholarly journals Quorum quenching activity of the PGPR Bacillus subtilis UD1022 alters nodulation efficiency of Sinorhizobium meliloti on Medicago truncatula

2020 ◽  
Author(s):  
Amanda Rosier ◽  
Pascale B. Beauregard ◽  
Harsh P. Bais
Keyword(s):  
Bacillus Subtilis ◽  
Plant Growth ◽  
Medicago Truncatula ◽  
Sinorhizobium Meliloti ◽  
Quorum Quenching ◽  
Agricultural System ◽  
Synergistic Activity ◽  
Sustainable Solutions ◽  
Plant Growth Promoting ◽  
Growth Promoting

AbstractPlant growth promoting rhizobacteria (PGPR) have enormous potential for solving some of the myriad challenges facing our global agricultural system. Intense research efforts are rapidly moving the field forward and illuminating the wide diversity of bacteria and their plant beneficial activities. In the development of better crop solutions using these PGPR, producers are including multiple different species of PGPR in their formulations in a ‘consortia’ approach. While the intention is to emulate more natural rhizomicrobiome systems, the aspect of bacterial interactions has not been properly regarded. By using a tri-trophic model of Medicago truncatula A17 Jemalong, its nitrogen (N)-fixing symbiont Sinorhizobium meliloti Rm8530 and the PGPR Bacillus subtilis UD1022, we demonstrate indirect influences between the bacteria affecting their plant growth promoting activities. Co-cultures of UD1022 with Rm8530 significantly reduced Rm8530 biofilm formation and downregulated quorum sensing (QS) genes responsible for symbiotically active biofilm production. This work also identifies the presence and activity of a quorum quenching lactonase in UD1022 and proposes this as the mechanism for non-synergistic activity of this model ‘consortium’. These interspecies interactions may be common in the rhizosphere and are critical to understand as we seek to develop new sustainable solutions in agriculture.

Sequencing, cloning, and heterologous expression of cyclomaltodextrin glucanotransferase of Bacillus firmus strain 37 in Bacillus subtilis WB800

2019 ◽  
Vol 42 (4) ◽  
pp. 621-629 ◽  
Author(s):  
Gabriela Gregolin Gimenez ◽  
Hernán Costa ◽  
Quirino Alves de Lima Neto ◽  
Maria Aparecida Fernandez ◽  
Susana Alicia Ferrarotti ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Heterologous Expression ◽  
Bacillus Firmus ◽  
Cyclomaltodextrin Glucanotransferase

scholarly journals Cellular Stoichiometry of Chemotaxis Proteins in Sinorhizobium meliloti

2020 ◽  
Vol 202 (14) ◽  
Author(s):  
Timofey D. Arapov ◽  
Rafael Castañeda Saldaña ◽  
Amanda L. Sebastian ◽  
W. Keith Ray ◽  
Richard F. Helm ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Bacillus Subtilis ◽  
Sinorhizobium Meliloti ◽  
Response Regulator ◽  
Bacterial Chemotaxis ◽  
Adaptor Proteins ◽  
Molar Ratio ◽  
Content Type ◽  
Chemotaxis Proteins ◽  
Chemotaxis System

ABSTRACT Chemotaxis systems enable microbes to sense their immediate environment, moving toward beneficial stimuli and away from those that are harmful. In an effort to better understand the chemotaxis system of Sinorhizobium meliloti, a symbiont of the legume alfalfa, the cellular stoichiometries of all ten chemotaxis proteins in S. meliloti were determined. A combination of quantitative immunoblot and mass spectrometry revealed that the protein stoichiometries in S. meliloti varied greatly from those in Escherichia coli and Bacillus subtilis. To compare protein ratios to other systems, values were normalized to the central kinase CheA. All S. meliloti chemotaxis proteins exhibited increased ratios to various degrees. The 10-fold higher molar ratio of adaptor proteins CheW1 and CheW2 to CheA might result in the formation of rings in the chemotaxis array that consist of only CheW instead of CheA and CheW in a 1:1 ratio. We hypothesize that the higher ratio of CheA to the main response regulator CheY2 is a consequence of the speed-variable motor in S. meliloti, instead of a switch-type motor. Similarly, proteins involved in signal termination are far more abundant in S. meliloti, which utilizes a phosphate sink mechanism based on CheA retrophosphorylation to inactivate the motor response regulator versus CheZ-catalyzed dephosphorylation as in E. coli and B. subtilis. Finally, the abundance of CheB and CheR, which regulate chemoreceptor methylation, was increased compared to CheA, indicative of variations in the adaptation system of S. meliloti. Collectively, these results mark significant differences in the composition of bacterial chemotaxis systems. IMPORTANCE The symbiotic soil bacterium Sinorhizobium meliloti contributes greatly to host-plant growth by fixing atmospheric nitrogen. The provision of nitrogen as ammonium by S. meliloti leads to increased biomass production of its legume host alfalfa and diminishes the use of environmentally harmful chemical fertilizers. To better understand the role of chemotaxis in host-microbe interaction, a comprehensive catalogue of the bacterial chemotaxis system is vital, including its composition, function, and regulation. The stoichiometry of chemotaxis proteins in S. meliloti has very few similarities to the systems in Escherichia coli and Bacillus subtilis. In addition, total amounts of proteins are significantly lower. S. meliloti exhibits a chemotaxis system distinct from known models by incorporating new proteins as exemplified by the phosphate sink mechanism.

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