Plant growth-promoting rhizobacteria represent a promising solution to enhancing agricultural productivity. Here, we screened phosphate solubilizing bacteria from the rhizospheric soil of Chenopodium quinoa Willd and assessed their plant-growth promoting rhizobacteria (PGPR) properties including production of indole-3-acetic acid (IAA), siderophores, hydrogen cyanide (HCN), ammonia and extracellular enzymes. We also investigated their tolerance to salt stress and their capacity to form biofilms. Two isolated strains, named QA1 and QF11, solubilized phosphate up to 346 mg/L, produced IAA up to 795.31 µg/mL, and tolerated up to 2 M NaCl in vitro. 16S rRNA and Cpn60 gene sequencing revealed that QA1 and QF11 belong to the genus Bacillus licheniformis and Enterobacter asburiae, respectively. In vivo, early plant growth potential showed that quinoa seeds inoculated either with QA1 or QF11 displayed higher germination rates and increased seedling growth. Under saline irrigation conditions, QA1 enhanced plant development/growth. Inoculation with QA1 increased leaf chlorophyll content index, enhanced P and K⁺ uptake and decreased plant Na⁺ uptake. Likewise, plants inoculated with QF11 strain accumulated more K⁺ and had reduced Na⁺ content. Collectively, our findings support the use of QA1 and QF11 as potential biofertilizers.

In recent years, the low Zn content of wheat has become critical. Consequently, solutions that can improve the Zn nutrition of wheat are highly researched. In the present investigation, we aimed to evaluate the potential benefits of phosphate-solubilizing bacteria isolated from Ziziphus lotus on wheat seedling growth. Based on the phosphate-solubilizing criteria, four isolated strains, J16, J143, J146, and J158, were identified by 16SrRNA gene sequencing as Pseudomonas moraviensis, Bacillus halotolerans, Enterobacter hormaechei, and Pseudomonas frederiksbergensis, respectively. Studies of the conventional properties of plant growth-promoting rhizobacteria (PGPR) showed that E. hormaechei J146 produced up to 550 mg·L⁻¹ of indole-3-acetic acid (IAA). Siderophores and ammonia were produced by all strains but cellulase was restricted to B. halotolerans J143, whereas proteases were missing in E. hormaechei J146 and P. frederiksbergensis J158. E. hormaechei J146 tolerate up to 1.5 mg·L⁻¹ of copper and cadmium, while B. halotolerans J143 withstood 1.5 mg·L⁻¹ of nickel. Strains B. halotolerant J143, E. hormaechei J146, and P. frederiksbergensis J158 remarkably improved wheat seed germination, plant growth, and Zn absorption. Lastly, nutrient measurement revealed that a wheat plant inoculated with E. hormaechei J146 and P. frederiksbergensis J158 increased its nitrogen and potassium uptake by up to 17%.

Introduction of quinoa (Chenopodium quinoa willd.), a gluten-free nutritious pseudo-cereal, outside its traditional growing areas exposed it to seedling damping-off. Here, we isolated eleven phosphate-solubilizing bacteria from the quinoa rhizosphere and assessed their effect on germination and seedlings growth. All isolates solubilized phosphate, produced indole3-acetic acid, hydrocyanic acid, siderophores, and ammonia. Genotypic analysis revealed that our strains are related to the genus of Bacillus, Pseudomonas, and Enterobacter. Strains Enterobacter asburiae (QD14, QE4, QE6, and QE16), Enterobacter sp. QE3, and Enterobacter hormaechei QE7 withstood 1.5 mg·L⁻¹ of cadmium sulfate, 0.5 mg·mL⁻¹ of nickel nitrate, and 1 mg·mL⁻¹ of copper sulfate. Moreover, all strains solubilized zinc from ZnO; P. Stutzeri QD1 and E. asburiae QD14 did not solubilize Zn₃(PO₄)₂ and CO₃Zn, whereas CO₃Zn was not solubilized by E. asburiae QE16. Bacillus atrophaeus S8 tolerated 11% NaCl. P. frederiksbergensis S6 and Pseudomonas sp. S7 induced biofilm formation. Anti-fusarium activity was demonstrated for E.asburiae QE16, P. stutzeri QD1, P. frederiksbergensis S6, Pseudomonas sp. S7, and B. atrophaeus S8. Lastly, inoculation of quinoa seeds with B. atrophaeus S8 and E. asburiae QB1 induced the best germination rate and seedling growth, suggesting their potential use as inoculants for salty and heavy metal or zinc contaminated soils.

Quinoa is renowned for its nutritional value and ability to withstand harsh environmental conditions such as salinity. In the present work, we isolated 34 phosphate solubilizing endophytic bacteria associated with the roots of quinoa plants. Based on phosphate solubilization efficiency and biochemical characterization, we selected one isolate named ED1. Ribotyping using partial 16S RNA gene analysis revealed that the selected isolate shares 99.7% identity with Serratia rubidaea. Plant growth promoting (PGP) studies showed that the ED1 strain solubilized complexed forms of phosphate (Ca₃(PO₄)₂). Zinc release from ZnO, Zn₃(PO₄)₂, or ZnCO₃ revealed the efficient ZnO solubilization by the ED1 strain. Except for proteases, the strain ED1 produced siderophores, cellulase, ammonia and exhibited oligonitrophilic features. Indole acetic acid (IAA) production was detected with and without the L-tryptophan precursor. Next, we demonstrated that the ED1 strain tolerated 1.5 M NaCl final concentration and exhibited intrinsic resistance to seven antibiotics frequently prescribed for medical use. Moreover, we found that ED1 strain withstood 2 mg/L of Cadmium and 1 mg/L of either Nickel or Copper. Furthermore, we observed that S. rubidaea ED1 stimulated quinoa seeds germination and seedlings growth under salt stress conditions. Lastly, we discuss the advantages versus disadvantages of applying the S. rubidaea ED1 strain as a beneficial agent for salty and/or heavy metals contaminated soils.

Plant Growth-Promoting Rhizobacteria (PGPR) have attracted much attention in agriculture biotechnology as biological inputs to sustain crop production. The present study describes a halotolerant phosphate solubilizing bacterium associated with quinoa plant roots. Based on a metabolic screening, one bacterial isolate, named QA2, was selected and screened for PGPR traits. This isolate solubilized both inorganic phosphate and zinc, produced indole-3-acetic acid, ammonia, hydrogen cyanide, cellulase, and (to be deleted) protease, and induced biofilm formation. We demonstrated that QA2 exhibited both antimicrobial and ion metabolism activities and tolerated high salt concentration at up to 11% NaCl. Genotyping analyses, using 16S rRNA and chaperonin cpn60 genes, revealed that QA2 belongs to the species of Bacillus velezensis. Using the quinoa model cultivated under a saline condition, we demonstrated that QA2 promoted plant growth and mitigated the saline irrigation effects. Analysis of harvested plants revealed that QA2 induced a significant increase of both leaf chlorophyll index by 120.86% (p < 0.05) and P uptake by 41.17% (p < 0.05), while the content of Na⁺ was drastically decreased. Lastly, a bibliometric data analysis highlighted the panoramic view of studies carried out so far on B. velezensis strains. Our investigation presents a holistic view of the potential application of B. velezensis as a biological inoculant to promote plant growth, control pathogen attacks, and mitigate the salinity effect of quinoa plants. Further investigations are still needed to demonstrate these effects in field conditions.

The concerns regarding Fowl Adenoviruses have gained significance in the poultry industry due to their association with various diseases, including Inclusion Body Hepatitis, Hepatitis-Hydropericardium Syndrome, and Adenoviral Gizzard Erosion (AGE). AGE is an emerging disease reported in several countries, particularly in Asia and Europe, causing significant economic losses in the poultry industry. In 2001, Fowl Adenovirus Serotype 1 was identified as the etiological agent of AGE in Japan. Since then, it has been spreading to other countries due to its transmission mode. Although Adenoviral Gizzard Erosion has been mostly described in broilers, it has also been observed in layers and pullets. This review offers a comprehensive analysis of Fowl Adenovirus Serotype 1, encompassing various key aspects of the virus. We also examine the pathogenesis and epidemiology of the virus, providing an overview of its distribution and prevalence in avian populations worldwide. Highlighting the most recent developments in serological and molecular techniques for virus detection, quantification, and genotyping and comparing them to conventional tests, this review aims to contribute to the understanding of the diagnostic workflow for this virus. Lastly, this review sheds light on some vaccine strategies to prevent Adenoviral Gizzard Erosion.