Genomic insights into the plant-associated lifestyle of Kosakonia radicincitans MUSA4, a diazotrophic plant-growth-promoting bacterium.

The process of nitrogen (N) fixation by plant-associated bacteria plays an indispensable role in the development of novel agricultural solutions worldwide. In this sense, it is of extreme importance to identify and understand the properties of efficient plant-growth-promoting bacteria (PGPB) that are able to fix N. In this study, the characterization and detailed genomic analysis of the diazotrophic bacterium Kosakonia radicincitans MUSA4, isolated from the internal leaf tissues of a banana tree in Brazil, were undertaken.

Genomic Analysis of the 1-Aminocyclopropane-1-Carboxylate Deaminase-Producing SC5 Reveals Its Multifaceted Roles in Soil and in Beneficial Interactions With Plants.

Beneficial 1-aminocyclopropane-1-carboxylate (ACC) deaminase-producing bacteria promote plant growth and stress resistance, constituting a sustainable alternative to the excessive use of chemicals in agriculture. In this work, the increased plant growth promotion activity of the ACC deaminase-producing SC5, its ability to limit the growth of phytopathogens, and the genomics behind these important properties are described in detail. SC5 displayed several active plant growth promotion traits and significantly increased cucumber plant growth and resistance against salt stress (100mmol/L NaCl) under greenhouse conditions.

Multiple plant hormone catabolism activities: an adaptation to a plant-associated lifestyle by Achromobacter spp.

Elaborating the plant hormone catabolic activities of bacteria is important for developing a detailed understanding of plant-microbe interactions. In this work, the plant hormone catabolic and plant growth promotion activities of Achromobacter xylosoxidans SOLR10 and A. insolitus AB2 are described.

Isolation and characterization of novel soil- and plant-associated bacteria with multiple phytohormone-degrading activities using a targeted methodology.

Ethylene (ET), salicylic acid (SA) and indole-3-acetic acid (IAA) are important phytohormones regulating plant growth and development, as well as plant-microbe interactions. Plant growth-promoting bacteria (PGPB) naturally associate with plants and facilitate plant growth through a variety of mechanisms, including the ability to modulate the concentrations of these phytohormones . Importantly, the wide presence of phytohormone degradation mechanisms amongst symbiotic and other soil- and plant-associated bacteria indicates that the ability to modulate phytohormone concentrations plays an important role in bacterial colonization and plant-growth promotion abilities.

The extreme plant-growth-promoting properties of Pantoea phytobeneficialis MSR2 revealed by functional and genomic analysis.

Numerous Pantoea strains are important because of the benefit they provide in the facilitation of plant growth. However, Pantoea have a high level of genotypic diversity and not much is understood regarding their ability to function in a plant beneficial manner. In the work reported here, the plant growth promotion activities and the genomic properties of the unusual Pantoea phytobeneficialis MSR2 are elaborated, emphasizing the genetic mechanisms involved in plant colonization and growth promotion.

Plant growth-promoting activities and genomic analysis of the stress-resistant STB1, a bacterium of agricultural and biotechnological interest.

In this work, the stress-resistant STB1 is characterized and its ability to promote plant growth under normal and stress conditions is demonstrated. The genomic sequence of this bacterium, and a detailed analysis of the genes involved in facilitating its stress resistance and plant growth-promoting activities is also reported. The STB1 genome is rich in genetic elements involved in multiple stress resistance, xenobiotic degradation, pathogen antagonistic activities, and other traits related to soil and rhizosphere colonization.

ACC deaminase plays a major role in Pseudomonas fluorescens YsS6 ability to promote the nodulation of Alpha- and Betaproteobacteria rhizobial strains.

Ethylene acts as a major regulator of the nodulation process of leguminous plants. Several rhizobial strains possess the ability to modulate plant ethylene levels through the expression of the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase; however, rhizobia present low enzymatic activities. One possible alternative to this problem resides on the use of free-living bacteria, such as Pseudomonas, presenting high levels of ACC deaminase activity that may be used as adjuvants in the nodulation process by decreasing inhibitory ethylene levels.

The modulation of leguminous plant ethylene levels by symbiotic rhizobia played a role in the evolution of the nodulation process.

Ethylene plays an important role in regulating the rhizobial nodulation process. Consequently, numerous strains of rhizobia possess the ability to decrease plant ethylene levels by the expression of the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase or via the production of rhizobitoxine, thus, leading to an increased ability to nodulate leguminous plants. Nevertheless, not much is understood about the prevalence of these ethylene modulation genes in different rhizobial groups nor their role in the evolution of the symbiotic process.

Microbially-enriched poultry litter-derived biochar for the treatment of acid mine drainage.

Sulfate-reducing bacteria (SRB) and a biochar array were used to reduce sulfate concentrations and the levels of metals in acid mine drainage (AMD) waters. Cow manure SRB-enriched biochar promoted sulfate reductions of 41% compared to original AMD, and 39% compared to other treatments (control, AMD sediment, sludge). Treatments reduced levels of all analyzed metals below Brazilian official standards.

Near-Complete Genome Sequence of Pseudomonas palleroniana MAB3, a Beneficial 1-Aminocyclopropane-1-Carboxylate Deaminase-Producing Bacterium Able To Promote the Growth of Mushrooms and Plants.

The near-complete genome sequence of MAB3, a 1-aminocyclopropane-1-carboxylate deaminase-producing bacterium isolated from an environmental soil mushroom, is presented here. The genome of MAB3 contains a single circular chromosome of 6.29 Mb and an average GC content of 60.

Exopolysaccharides from Lactobacillus plantarum induce biochemical and physiological alterations in tomato plant against bacterial spot.

This study aimed to evaluate the effectiveness of exopolysaccharides (EPS) produced by Lactobacillus plantarum in controlling bacterial spot and eliciting defense mechanisms, and verify alterations in the tomato plant physiological responses. Tomato plants with five definitive leaves were sprayed with EPS, acibenzolar-S-methyl (ASM, positive control), or distilled water (negative control) and inoculated with Xanthomonas gardneri after 3 days. Local and systemic protection was evaluated 7, 15, and 21 days after inoculation.

Ethylene and 1-Aminocyclopropane-1-carboxylate (ACC) in Plant-Bacterial Interactions.

Ethylene and its precursor 1-aminocyclopropane-1-carboxylate (ACC) actively participate in plant developmental, defense and symbiotic programs. In this sense, ethylene and ACC play a central role in the regulation of bacterial colonization (rhizospheric, endophytic, and phyllospheric) by the modulation of plant immune responses and symbiotic programs, as well as by modulating several developmental processes, such as root elongation. Plant-associated bacterial communities impact plant growth and development, both negatively (pathogens) and positively (plant-growth promoting and symbiotic bacteria).

Improvement of Cupriavidus taiwanensis Nodulation and Plant Growth Promoting Abilities by the Expression of an Exogenous ACC Deaminase Gene.

Several rhizobial strains possess the ability to modulate leguminous plants ethylene levels by producing the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase. While the effect of ACC deaminase has been studied in several rhizobia belonging to the Alphaproteobacteria class, not much is understood about its impact in the nodulation abilities of rhizobia belonging to the Betaproteobacteria class, which are common symbionts of Mimosa species. In this work, we report the impact of ACC deaminase production by the Betaproteobacterium, Cupriavidus taiwanensis STM894, and its role in the nodulation of Mimosa pudica.

Selection and characterization of coal mine autochthonous rhizobia for the inoculation of herbaceous legumes.

Coal open pit mining in the South of Santa Catarina state (Brazil) was inappropriately developed, affecting approximately 6.700 ha. Re-vegetation is an alternative for the recovery of these areas.

Non-specific transient mutualism between the plant parasitic nematode, Bursaphelenchus xylophilus, and the opportunistic bacterium Serratia quinivorans BXF1, a plant-growth promoting pine endophyte with antagonistic effects.

The aim of this study is to understand the biological role of Serratia quinivorans BXF1, a bacterium commonly found associated with Bursaphelenchus xylophilus, the plant parasitic nematode responsible for pine wilt disease. Therefore, we studied strain BXF1 effect in pine wilt disease. We found that strain BXF1 promoted in vitro nematode reproduction.

Morphological and ultrastructural characterization of the acidophilic and lipid-producer strain Chlamydomonas acidophila LAFIC-004 (Chlorophyta) under different culture conditions.

Chlamydomonas acidophila LAFIC-004 is an acidophilic strain of green microalgae isolated from coal mining drainage. In the present work, this strain was cultivated in acidic medium (pH 3.6) under phototrophic, mixotrophic, and heterotrophic regimes to determine the best condition for growth and lipid production, simultaneously assessing possible morphological and ultrastructural alterations in the cells.

Transfer and consumption of oxygen during the cultivation of the ectomycorrhizal fungus Rhizopogon nigrescens in an airlift bioreactor.

The study had the objective of examining the aspects involved in the cultivation of ectomycorrhizal fungi for the production of commercially sustainable inoculant to attend the demands of the seedling nursery industry. It focused on certain parameters, such as the oxygen consumption levels, during the cultivation of the ectomycorrhizal fungus Rhizopogon nigrescens CBMAI 1472, which was performed in a 5-L airlift bioreactor. The dynamic method was employed to determine the volumetric coefficient for the oxygen transfer (k a) and the specific oxygen uptake rate (Q ).

Arbuscular mycorrhizal fungi in the growth and extraction of trace elements by Chrysopogon zizanioides (vetiver) in a substrate containing coal mine wastes.

Vetiver (Chrysopogon zizanioides) is a fast-growing, high biomass producing plant employed for environmental rehabilitation. The study evaluated the effects of arbuscular mycorrhizal fungi (AMF) on the growth and trace element phytoextracting capabilities of vetiver in a substrate containing coalmine wastes in Southern Brazil. AMF included Acaulospora colombiana, Acaulospora morrowiae, Acaulospora scrobiculata, Dentiscutata heterogama, Gigaspora margarita, and Rhizophagus clarus.

Apple Aminoacid Profile and Yeast Strains in the Formation of Fusel Alcohols and Esters in Cider Production.

The amino acid profile in dessert apple must and its effect on the synthesis of fusel alcohols and esters in cider were established by instrumental analysis. The amino acid profile was performed in nine apple musts. Two apple musts with high (>150 mg/L) and low (<75 mg/L) nitrogen content, and four enological yeast strains, were used in cider fermentation.

New insights into 1-aminocyclopropane-1-carboxylate (ACC) deaminase phylogeny, evolution and ecological significance.

The main objective of this work is the study of the phylogeny, evolution and ecological importance of the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase, the activity of which represents one of the most important and studied mechanisms used by plant growth-promoting microorganisms. The ACC deaminase gene and its regulatory elements presence in completely sequenced organisms was verified by multiple searches in diverse databases, and based on the data obtained a comprehensive analysis was conducted. Strain habitat, origin and ACC deaminase activity were taken into account when analyzing the results.

Antiherpetic activity of a sulfated polysaccharide from Agaricus brasiliensis mycelia.

Sulfated polysaccharides are good candidates for drug discovery in the treatment of herpetic infections. Agaricus brasiliensis (syn A. subrufescens, A.

Growth of the Ectomycorrhizal Fungus Pisolithus Microcarpus in different nutritional conditions.

The most important plant species employed in reforestation programs depend on ectomycorrhizal fungi for their establishment and growth. The exploitation of this symbiosis to improve forest productivity requires fungal inoculants in a large scale level. To develop such a technology it is necessary to define the optimal composition of the culture medium for each fungus.