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PloS One 2024Plant growth-promoting rhizobacteria (PGPR) applications have emerged as an ideal substitute for synthetic chemicals by their ability to improve plant nutrition and...
Plant growth-promoting rhizobacteria (PGPR) applications have emerged as an ideal substitute for synthetic chemicals by their ability to improve plant nutrition and resistance against pathogens. In this study, we isolated fourteen root endophytes from healthy wheat roots cultivated in Tunisia. The isolates were identified based from their 16S rRNA gene sequences. They belonged to Bacillota and Pseudomonadota taxa. Fourteen strains were tested for their growth-promoting and defense-eliciting potentials on durum wheat under greenhouse conditions, and for their in vitro biocontrol power against Fusarium culmorum, an ascomycete responsible for seedling blight, foot and root rot, and head blight diseases of wheat. We found that all the strains improved shoot and/or root biomass accumulation, with Bacillus mojavensis, Paenibacillus peoriae and Variovorax paradoxus showing the strongest promoting effects. These physiological effects were correlated with the plant growth-promoting traits of the bacterial endophytes, which produced indole-related compounds, ammonia, and hydrogen cyanide (HCN), and solubilized phosphate and zinc. Likewise, plant defense accumulations were modulated lastingly and systematically in roots and leaves by all the strains. Testing in vitro antagonism against F. culmorum revealed an inhibition activity exceeding 40% for five strains: Bacillus cereus, Paenibacillus peoriae, Paenibacillus polymyxa, Pantoae agglomerans, and Pseudomonas aeruginosa. These strains exhibited significant inhibitory effects on F. culmorum mycelia growth, sporulation, and/or macroconidia germination. P. peoriae performed best, with total inhibition of sporulation and macroconidia germination. These finding highlight the effectiveness of root bacterial endophytes in promoting plant growth and resistance, and in controlling phytopathogens such as F. culmorum. This is the first report identifying 14 bacterial candidates as potential agents for the control of F. culmorum, of which Paenibacillus peoriae and/or its intracellular metabolites have potential for development as biopesticides.
Topics: Fusarium; Triticum; Endophytes; Biological Control Agents; Plant Diseases; Plant Roots; Tunisia; Bacteria; RNA, Ribosomal, 16S
PubMed: 38758965
DOI: 10.1371/journal.pone.0300791 -
Proteomics May 2024Mass spectrometry proteomics data are typically evaluated against publicly available annotated sequences, but the proteogenomics approach is a useful alternative. A...
Understanding bacterial pathogen diversity: A proteogenomic analysis and use of an array of genome assemblies to identify novel virulence factors of the honey bee bacterial pathogen Paenibacillus larvae.
Mass spectrometry proteomics data are typically evaluated against publicly available annotated sequences, but the proteogenomics approach is a useful alternative. A single genome is commonly utilized in custom proteomic and proteogenomic data analysis. We pose the question of whether utilizing numerous different genome assemblies in a search database would be beneficial. We reanalyzed raw data from the exoprotein fraction of four reference Enterobacterial Repetitive Intergenic Consensus (ERIC) I-IV genotypes of the honey bee bacterial pathogen Paenibacillus larvae and evaluated them against three reference databases (from NCBI-protein, RefSeq, and UniProt) together with an array of protein sequences generated by six-frame direct translation of 15 genome assemblies from GenBank. The wide search yielded 453 protein hits/groups, which UpSet analysis categorized into 50 groups based on the success of protein identification by the 18 database components. Nine hits that were not identified by a unique peptide were not considered for marker selection, which discarded the only protein that was not identified by the reference databases. We propose that the variability in successful identifications between genome assemblies is useful for marker mining. The results suggest that various strains of P. larvae can exhibit specific traits that set them apart from the established genotypes ERIC I-V.
PubMed: 38742951
DOI: 10.1002/pmic.202300280 -
Microbiology Resource Announcements Jun 2024The genome of a spore-forming bacterium isolated from the spacecraft assembly facility of the Phoenix mission, was generated via hybrid assembly by merging short and...
The genome of a spore-forming bacterium isolated from the spacecraft assembly facility of the Phoenix mission, was generated via hybrid assembly by merging short and long reads. Examining this genome may shed light on strategies to minimize the risk of contaminating extraterrestrial environments with Earth-based microorganisms.
PubMed: 38742883
DOI: 10.1128/mra.01265-23 -
Current Microbiology May 2024As a primary nutrient in agricultural soils, phosphorus plays a crucial but growth-limiting role for plants due to its complex interactions with various soil elements....
As a primary nutrient in agricultural soils, phosphorus plays a crucial but growth-limiting role for plants due to its complex interactions with various soil elements. This often results in excessive phosphorus fertilizer application, posing concerns for the environment. Agri-research has therefore shifted focus to increase fertilizer-use efficiency and minimize environmental impact by leveraging plant growth-promoting rhizobacteria. This study aimed to evaluate the in-field incremental effect of inorganic phosphate concentration (up to 50 kg/ha/P) on the ability of two rhizobacterial isolates, Lysinibacillus sphaericus (T19), Paenibacillus alvei (T29), from the previous Breedt et al. (Ann Appl Biol 171:229-236, 2017) study on maize in enhancing the yield of commercially grown Duzi® cultivar wheat. Results obtained from three seasons of field trials revealed a significant relationship between soil phosphate concentration and the isolates' effectiveness in improving wheat yield. Rhizospheric samples collected at flowering during the third season, specifically to assess phosphatase enzyme activity at the different soil phosphate levels, demonstrated a significant decrease in soil phosphatase activity when the phosphorus rate reached 75% for both isolates. Furthermore, in vitro assessments of inorganic phosphate solubilization by both isolates at five increments of tricalcium phosphate-amended Pikovskaya media found that only isolate T19 was capable of solubilizing tricalcium at concentrations exceeding 3 mg/ml. The current study demonstrates the substantial influence of inorganic phosphate on the performance of individual rhizobacterial isolates, highlighting that this is an essential consideration when optimizing these isolates to increase wheat yield in commercial cultivation.
Topics: Triticum; Phosphates; Soil Microbiology; Soil; Rhizosphere; Fertilizers; Paenibacillus; Phosphorus
PubMed: 38734822
DOI: 10.1007/s00284-024-03685-x -
Saudi Journal of Biological Sciences Jun 2024American foulbrood (AFB) is a harmful honeybee disease primarily caused by . The study aims to isolate and identify the AFB causative agent and their specific phages...
American foulbrood (AFB) is a harmful honeybee disease primarily caused by . The study aims to isolate and identify the AFB causative agent and their specific phages to use as a new biological method for AFB disease control. Eight apiaries were inspected for AFB infections. Symptoms of diseased brood comb, were odd brood cells with soft brown decayed brood amongst healthy brood, were identified in the field and demonstrated the prevalence of AFB in every apiary. Three isolates were identified using traditional techniques using a 452-bp PCR amplicon specific to the bacterial 16SrRNA gene and was compared between isolates. Additionally, specific phages of strains were applied to examine their efficiency in reducing the infection rate under the apiary condition. The infection rate was reduced to approximately 94.6 to 100 % through the application of a phage mixture, as opposed to 20 to 85.7 % when each phage was administered individually or 78.6 to 88.9 % when antibiotic treatment was implemented. Histological studies on phage-treated bee larvae revealed some cells regaining normal shape, with prominent nuclei and microvilli. The gastrointestinal tract showed normal longitudinal and circular muscles, unlike bee larvae treated with bacterial strains with abnormal and destroyed tissues, as shown by the basement membrane surrounding the mid-gut epithelium. Phage techniques exhibited promise in resolving the issue of AFB in honeybees due to their ease of application, comparatively lower cost, and practicality for beekeepers in terms of laboratory preparation.
PubMed: 38706719
DOI: 10.1016/j.sjbs.2024.104002 -
Brazilian Journal of Microbiology :... Jun 2024Alginate is a major extra polymeric substance in the biofilm formed by mucoid Pseudomonas aeruginosa. It is the main proven perpetrator of lung infections in patients...
Alginate is a major extra polymeric substance in the biofilm formed by mucoid Pseudomonas aeruginosa. It is the main proven perpetrator of lung infections in patients suffering from cystic fibrosis. Alginate lyases are very important in the treatment of cystic fibrosis. This study evaluated the role of standalone and in conjugation, effect of alginate lyase of SG4 + isolated from Paenibacillus lautus in enhancing in vitro bactericidal activity of gentamicin and amikacin on mucoid P. aeruginosa. Using Response Surface Methodology (RSM) alginate lyase SG4 + production was optimized in shake flask and there 8.49-fold enhancement in enzyme production. In fermenter, maximum growth (10.15 mg/ml) and alginate lyase (1.46 International Units) production, 1.71-fold was increased using Central Composite Design (CCD). Further, fermentation time was reduced from 48 to 20 h. To the best of our knowledge this is the first report in which CCD was used for fermenter studies to optimize alginate lyase production. The K and V of purified enzyme were found to be 2.7 mg/ml and 0.84 mol/ml-min, respectively. The half-life (t ) of purified alginate lyase SG4 + at 37 °C was 180 min. Alginate lyase SG4 + in combination with gentamicin and amikacin eradiated 48.4- 52.3% and 58- 64.6%, alginate biofilm formed by P. aeruginosa strains, respectively. The study proves that alginate lyase SG4 + has excellent exopolysaccharide disintegrating ability and may be useful in development of potent therapeutic agent to treat P. aeruginosa biofilms.
Topics: Pseudomonas aeruginosa; Biofilms; Polysaccharide-Lyases; Anti-Bacterial Agents; Paenibacillus; Gentamicins; Amikacin; Fermentation; Microbial Sensitivity Tests; Bacterial Proteins; Alginates
PubMed: 38705960
DOI: 10.1007/s42770-024-01334-w -
Journal of Food Protection Jul 2024Beverage innovation is a growing trend with a reliance on comanufacturing relationships to launch products quickly. A recent comanufacturing relationship is the...
Beverage innovation is a growing trend with a reliance on comanufacturing relationships to launch products quickly. A recent comanufacturing relationship is the utilization of dairy processing facilities to process plant-based beverages using high-temperature short-time (HTST) pasteurization. While the shelflife of HTST bovine milk is well established at 21 days, retailers are expecting new refrigerated beverages to achieve a 60-day shelflife. Little is known about the microbial stability of these new beverages, particularly those with complex formulations. Our objective was to identify bacterial taxa leading to the spoilage of four coconut-based creamers and their potential sources (raw ingredients or packaging). We used a multifaceted approach including plate counting and 16S rRNA metabarcoding to monitor microbial growth in products throughout shelflife (60 d, 4 °C), and cold enrichment (7 °C, 11 d) of ingredients and packaging. Nearly all product units (25/26) had elevated microbial loads (>4.3 log CFU/mL) prior to the 60-d target, with early spoilage detected at 21 d. Key spoilage taxa included Pseudomonas, Streptococcus, Aerococcus, Paenibacillus, Sphingomonas, and Oceanobacillus. Pseudomonas were responsible for "early" product spoilage (21-32 d), whereas Oceanobacillus were important in products with very "late" spoilage (60-62 d). All key spoilage taxa were identified in cold enrichments of multiple units of waxboard cartons. Paenibacillus was the dominant bacterium in 47% (10/21) of product units. In addition to carton samples, Paenibacillus was also identified in one raw ingredient (mushroom extract). Metabarcoding identified Listeria sensu stricto as a dominant taxon in three individual product units from three distinct production lots. Listeria was also found in 31% (5/16) of cold enrichments of individual cartons. Taxa responsible for spoilage of plant-based beverages were identified as well as demonstrating packaging as an important contamination source.
Topics: Cocos; Bacteria; Food Microbiology; Food Contamination; Colony Count, Microbial; Animals; Beverages; Cattle; Food Packaging
PubMed: 38692353
DOI: 10.1016/j.jfp.2024.100284 -
Microbiology Resource Announcements Jun 2024Streptomycin thallous acetate actidione medium is typically used to isolate bacteria from food. Using this medium, three bacterial strains were isolated from the...
Streptomycin thallous acetate actidione medium is typically used to isolate bacteria from food. Using this medium, three bacterial strains were isolated from the environment. Genomic sequences demonstrated that these bacteria are of the genera and and are of biotechnological interest.
PubMed: 38682917
DOI: 10.1128/mra.00199-24 -
Journal of Water and Health Apr 2024This study assessed the bacteriological quality of raw, treated, and distributed water from Ede-Erinle and Opa reservoirs in Osun State, Nigeria. This was to determine...
This study assessed the bacteriological quality of raw, treated, and distributed water from Ede-Erinle and Opa reservoirs in Osun State, Nigeria. This was to determine the potability of water from these waterwork stations. Eighteen sampling points were established across the two reservoir networks for this study. Samples were collected bi-monthly for two annual cycles. Serial dilution and pour plate methods were employed for the enumeration of bacterial load. Total heterotrophic bacteria count (THBC) and total coliform bacteria count (TCBC) were enumerated on nutrient and MacConkey agar at 37 °C, respectively. Bacterial isolates were characterized using biochemical identification methods with reference to . Bacterial isolates and biofilm formation were further identified molecularly through the PCR method using specific universal primers. Mean values of THBC and TCBC in distributed water from Ede-Erinle (9.61 × 10 ± 1.50 × 10 CFU/mL; 69.56 ± 26.81 CFU/mL) and Opa waterworks (9.58 × 10 ± 2.55 × 10 CFU/mL; 142.94 ± 44.41 CFU/mL) exceeded permissible limits for drinking water. , , , and showed biofilm-forming capacity. The study concluded that the presence of coliforms and biofilm-forming bacteria in distributed water implies that the water is unfit for consumption without further treatment.
Topics: Nigeria; Biofilms; Enterobacteriaceae; Drinking Water; Water Microbiology; Water Supply; Bacteria; Water Purification
PubMed: 38678421
DOI: 10.2166/wh.2024.302 -
Waste Management (New York, N.Y.) Jun 2024Carbon monoxide (CO) formation has been observed during composting of various fractions of organic waste. It was reported that this production can be biotic, associated...
Carbon monoxide (CO) formation has been observed during composting of various fractions of organic waste. It was reported that this production can be biotic, associated with the activity of microorganisms. However, there are no sources considering the microbial communities producing CO production in compost. This preliminary research aimed to isolate and identify microorganisms potentially responsible for the CO production in compost collected from two areas of the biowaste pile: with low (118 ppm) and high CO concentration (785 ppm). Study proved that all isolates were bacterial strains with the majority of rod-shaped Gram-positive bacteria. Both places can be inhabited by the same bacterial strains, e.g. Bacillus licheniformis and Paenibacillus lactis. The most common were Bacillus (B. licheniformis, B. haynesii, B. paralicheniformis, and B. thermolactis). After incubation of isolates in sealed bioreactors for 4 days, the highest CO levels in the headspace were recorded for B. paralicheniformis (>1000 ppm), B. licheniformis (>800 ppm), and G. thermodenitrificans (∼600 ppm). High CO concentrations were accompanied by low O (<6%) and high CO levels (>8%). It is recommended to analyze the expression of the gene encoding CODH to confirm or exclude the ability of the identified strains to convert CO to CO.
Topics: Carbon Monoxide; Composting; Soil Microbiology; Bacillus; Bioreactors; Bacteria
PubMed: 38677142
DOI: 10.1016/j.wasman.2024.04.044