Aislamiento y caracterización de bacterias promotoras de crecimiento vegetal asociadas a la rizosfera de Megathyrsus maximus

Caracterização morfofisiológica, molecular e funcional de Mycobacterium agroflorensis com potencial para o desenvolvimento de bioinsumos e promoção do crescimento vegetal

Bacterial inoculation improved plant development and demonstrated promising potential for application in sustainable agricultural systems, highlighting the biotechnological potential of M. agroflorensis as a candidate for the development of agricultural bioinputs, contributing to low-carbon agriculture and advancing research in agricultural microbiology.

Biotización con Bacterias Promotoras del Crecimiento Vegetal en Microplantas de Papa

The use of beneficial microorganisms during the acclimatization and hardening of micropropagated potato plants reduces the need for chemical inputs and increases plant survival under various biotic and abiotic stress conditions. The combined application of these biotechnological techniques is known as biotization. This study aimed to quantify the ef fect of inoculation with Pseudomonas putida (strain M11) and Stenotrophomonas rhizophila (strain KN01) on the morphology of micropropagated potato plants during acclimatization and hardening. Potato plantlets were micropropagated on Murashige and Skoog (MS) culture medium, bacterial strains were characterized in vitro, and morphometric variables and plantlet survival  were  evaluated. P. putida (M11)  exhibited  phosphate-solubilizing  potential, nitrogen-fixing ability, and the capacity to produce indole-3-acetic acid (IAA) and siderophores, resulting in increased plant survival. In contrast, S. rhizophila did not exhibit qualitative plant growth-promoting traits in vitro; however, during acclimatization it significantly increased plant height, stem diameter, and root length. During hardening, plantlets inoculated with P. putida showed greater fresh and dry biomass, as well as increased root length. No significant dif ferences were found between inoculation methods, whereas significant dif ferences were observed among treatments. These results suggest a possible synergistic interaction between micropropagated potato plants and the bacterial strains evaluated.

Promoción del crecimiento en algodón por bacterias endófitas diazotróficas

Endophytic bacteria can stimulate nutrient uptake and plant growth through diverse biochemical and physiological mechanisms; however, studies in cotton (Gossypium hirsutum L.), a crop of high economic relevance in Brazil, remain limited. In this context, the objective of this study was to isolate, characterize, and evaluate free-living diazotrophic strains, determining their functional potential in vitro. A total of 77 strains were obtained from three cultivars grown in Sapezal-MT (TMG47B2RF, TMG44B2RF, and FM985GLTP), using NFb medium (nitrogen-free semi-solid medium) and YMA (yeast extract mannitol agar). The strains were evaluated for nitrogen fixation, indole-3-acetic acid (IAA) production, phosphate and potassium silicate solubilization, and in vitro plant growth promotion in TMG47B2RF under 50 % of the recommended N dose, in a completely randomized design with three replications. Data were subjected to multivariate analysis. Among the evaluated strains, 61 showed nitrogen fixation ability and 20 produced IAA above 3.87 µg.mL⁻¹. Strains AL263 (IAA), AL046 (K₂SiO₄), and AL226 (N and Ca₃(PO₄)₂) stood out. Multivariate analysis identified AL232 and AL039 as the most promising strains, promoting significant increases in shoot and root biomass even under 50 % N reduction, with performance comparable to the 100 % N control and to Azospirillum brasilense Ab-V5. These results demonstrate that native multifunctional endophytic strains can sustain cotton growth under reduced nitrogen fertilization, highlighting their potential as a basis for the development of more efficient and sustainable bioinoculants.

Avaliação in vitro de produtos naturais sobre Erwinia psidii por microdiluição em caldo e disco-difusão

Integrative functional profiling of rhizospheric and endophytic bacteria reveals Lelliottia aquatilis as a multifunctional PGPR in Himalayan ecosystems

This study introduces L. aquatilis strain MC3 as an emerging candidate for bioinoculant development and one of the first reports for identification of L. aquatilis as multifunctional PGPR from Himalayan ecosystems.

DIVERSITE DES RHIZOBACTERIES DE LA RHIZOSPHERE DES GENOTYPES D ANACARDIER (ANACARDIUM OCCIDENTALE L.)TOP 24 DE LA STATION DE RECHERCHE DE LATAHA (CNRA) ET CARACTERISATION DE LEUR POTENTIEL DANS LA PROMOTION DE LA CROISSANCE DES PLANTES (PGPR)

Rhizobacteria play a major role in the functioning of agricultural ecosystems by contributing to plant nutrition and growth. However, information regarding the diversity and functional properties of bacteria associated with cashew genotypes in plot Top 24 in Lataha remains limited. This study aimed to characterize these bacterial communities and assess their potential as plant growth-promoting bacteria (PGPR). Rhizosphere soil samples were collected from cashew genotypes in plot Top 24 and from citrus trees located on the periphery. The physicochemical properties of the soils were determined,and bacteria were isolated on LB and characterized by Gram staining and biochemical tests. The main PGPR traits evaluated included phosphate solubilization, the production of indole -3- acetic acid (IAA), ammonia (NH3), and hydrocyanic acid (HCN), atmospheric nitrogen fixation, as well as nitrate reductase and urease activities. The soils studied were generally acidic (pH ranging from 3.71 to 5.24) with variations in moisture and electrical conductivity depending on the rhizosphere. Twenty-five bacterial isolates were obtained, including 21 from cashew genotypes and 4 from citrus. The majority of the strains were Gram-negative bacilli and exhibited catalase and oxidase activity. PGPR assays revealed no phosphate solubilization or HCN production, while several isolates produced AIA and a high proportion exhibited nitrogen-fixing ability and nitrate reductase activity.