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Heliyon Mar 2023Barley scald is very important in temperate and wet regions worldwide and has become one of the most important foliar diseases. Before the development of recent... (Review)
Review
Barley scald is very important in temperate and wet regions worldwide and has become one of the most important foliar diseases. Before the development of recent technologies, several scientists had argued that is the causal agent of scald disease. However, the causal agent of this disease was revised and recognized as . Again recently, was suggested to be replaced as the causal agent of . The disease outbreak is depending on cool and frequent rainfall. Because of scald disease significance, numerous management practices have been advocated. Then, resistance materials, and mixing of resistant and susceptible cultivars have been used as the best management methods. Several studies have demonstrated that some cultivars and landraces of barley are resistant to scald disease during the seedling and adult growth stages. The first cultivar is "Atlas 46″ which was created from the cultivar "Turk". From biological method: , KaI245, and are very effective in treating this disease. Finally, as a last option, different fungicides have been suggested. Pathogenicity testing, seed treatments, tillage, cultivar mixtures, and biological control are all commonly overlooked in developing countries. Cultural practices such as times of fungicide application, appropriate time of sowing to scape disease, and tillage practices which are adopted for other diseases are greatly missed for scald disease. Then, we are intended to assess the various findings available on barley scald biology, taxonomy, and management.
PubMed: 36938428
DOI: 10.1016/j.heliyon.2023.e14315 -
Applied and Environmental Microbiology Jun 2022Despite being unicellular organisms, bacteria undergo complex regulation mechanisms which coordinate different physiological traits. Among others, DegU, DegS, and Spo0A...
Despite being unicellular organisms, bacteria undergo complex regulation mechanisms which coordinate different physiological traits. Among others, DegU, DegS, and Spo0A are the pleiotropic proteins which govern various cellular responses and behaviors. However, the functions and regulatory networks between these three proteins are rarely described in the highly interesting bacterium Paenibacillus polymyxa. In this study, we investigate the roles of DegU, DegS, and Spo0A by introduction of targeted point mutations facilitated by a CRISPR-Cas9-based system. In total, five different mutant strains were generated, the single mutants DegU Q218*, DegS L99F, and Spo0A A257V, the double mutant DegU Q218* DegS L99F, and the triple mutant DegU Q218* DegS L99F Spo0A A257V. Characterization of the wild-type and the engineered strains revealed differences in swarming behavior, conjugation efficiency, sporulation, and viscosity formation of the culture broth. In particular, the double mutant DegU Q218* DegS L99F showed a significant increase in conjugation efficiency as well as a stable exopolysaccharides formation. Furthermore, we highlight similarities and differences in the roles of DegU, DegS, and Spo0A between P. polymyxa and related species. Finally, this study provides novel insights into the complex regulatory system of P. polymyxa DSM 365. To date, only limited knowledge is available on how complex cellular behaviors are regulated in P. polymyxa. In this study, we investigate several regulatory proteins which play a role in governing different physiological traits. Precise targeted point mutations were introduced to their respective genes by employing a highly efficient CRISPR-Cas9-based system. Characterization of the strains revealed some similarities, but also differences, to the model bacterium Bacillus subtilis with regard to the regulation of cellular behaviors. Furthermore, we identified several strains which have superior performance over the wild-type. The applicability of the CRISPR-Cas9 system as a robust genome editing tool, in combination with the engineered strain with increased genetic accessibility, would boost further research in P. polymyxa and support its utilization for biotechnological applications. Overall, our study provides novel insights, which will be of importance in understanding how multiple cellular processes are regulated in species.
Topics: Bacillus subtilis; Bacterial Proteins; CRISPR-Cas Systems; Paenibacillus polymyxa; Point Mutation
PubMed: 35588272
DOI: 10.1128/aem.00164-22 -
Plants (Basel, Switzerland) Nov 2020Copper (Cu) is a micronutrient that assumes a principal role in plant growth and development. However, its excess concentration in soil is imperiling crop productivity....
Copper (Cu) is a micronutrient that assumes a principal role in plant growth and development. However, its excess concentration in soil is imperiling crop productivity. Inoculation with different bacterial strains in cereals could modify growth traits, photosynthetic effectiveness, and generation of strong antioxidant defense systems to make them more tolerant of Cu stress. Therefore, a pot study was designed to test plant growth-promoting rhizobacteria (PGPR) including and to Cu exposed maize ( L.) plants. Increasing Cu (100 to 500 µM of CuSO) concentration decreased growth traits, photosynthetic pigments, soluble sugars, phosphorous (P) and potassium (K) contents, and the activity of catalase (CAT) but increased proline and malondialdehyde (MDA) content, the activity of peroxidase (POD) and Cu ions at root and shoot level. Moreover, the bacterial treatment also modulated the antioxidant capability in stress-free plants. Nevertheless, inoculation with and alleviated Cu-induced growth, photosynthetic pigments and mineral nutrient (P and K) on one hand and regulating the pools of osmolytes and antioxidant enzymes, whilst simultaneously reducing MDA and Cu root and shoot contents. These improved activities of antioxidant enzymes and the regulation of osmolytes content elicited by the blend of bacterial inoculation would have retained the ability of maize plants to confer resilience to Cu stress. This study further affirms that the application of two specific bacterial strains to maize plants proved very effective to ameliorate the Cu toxicity.
PubMed: 33171623
DOI: 10.3390/plants9111513 -
Microbial Biotechnology Mar 2024Paenibacillus polymyxa is a non-pathogenic, Gram-positive bacterium endowed with a rich and versatile metabolism. However interesting, this bacterium has been seldom...
Paenibacillus polymyxa is a non-pathogenic, Gram-positive bacterium endowed with a rich and versatile metabolism. However interesting, this bacterium has been seldom used for bioproduction thus far. In this study, we engineered P. polymyxa for isobutanol production, a relevant bulk chemical and next-generation biofuel. A CRISPR-Cas9-based genome editing tool facilitated the chromosomal integration of a synthetic operon to establish isobutanol production. The 2,3-butanediol biosynthesis pathway, leading to the main fermentation product of P. polymyxa, was eliminated. A mutant strain harbouring the synthetic isobutanol operon (kdcA from Lactococcus lactis, and the native ilvC, ilvD and adh genes) produced 1 g L isobutanol under microaerobic conditions. Improving NADPH regeneration by overexpression of the malic enzyme subsequently increased the product titre by 50%. Network-wide proteomics provided insights into responses of P. polymyxa to isobutanol and revealed a significant metabolic shift caused by alcohol production. Glucose-6-phosphate 1-dehydrogenase, the key enzyme in the pentose phosphate pathway, was identified as a bottleneck that hindered efficient NADPH regeneration through this pathway. Furthermore, we conducted culture optimization towards cultivating P. polymyxa in a synthetic minimal medium. We identified biotin (B7), pantothenate (B5) and folate (B9) to be mutual essential vitamins for P. polymyxa. Our rational metabolic engineering of P. polymyxa for the production of a heterologous chemical sheds light on the metabolism of this bacterium towards further biotechnological exploitation.
Topics: Paenibacillus polymyxa; Carbon; NADP; Oxidation-Reduction; Paenibacillus; Metabolic Engineering; Butanols
PubMed: 38529712
DOI: 10.1111/1751-7915.14438 -
Frontiers in Microbiology 2023Pitaya canker, caused by , is one of the most important fungal diseases that cause significant losses in production. To replace chemical pesticides, the use of...
Pitaya canker, caused by , is one of the most important fungal diseases that cause significant losses in production. To replace chemical pesticides, the use of biocontrol strains to manage plant diseases has been the focus of research. In this study, the bacterial strain AF01, identified as , exhibited significant antifungal effects against and four other pitaya fungal pathogens. The strain AF01 produces 13 fusaricidins, which directly inhibit mycelial growth, spore germination and germ tube elongation by causing the membrane integrity and cell ultrastructure to incur irreversible damage. Pot experiment and yield test confirmed that AF01 provided preservative effects by reducing the disease index. In comparison to the untreated control groups, RNA-seq data showed that AF01 selectively blocked some transcription and translation processes and inhibited RNA and DNA structural dynamics, energy production and conversion, and signal transduction, particularly cell wall biosynthesis, changes in membrane permeability, and impairment of protein biosynthesis. Thus, AF01 could be potentially useful as a suitable biocontrol agent for pitaya canker.
PubMed: 37266020
DOI: 10.3389/fmicb.2023.1188722 -
Frontiers in Bioengineering and... 2022Production of some antimicrobial peptides by bacterial producers is a resource-intensive process, thus, using inexpensive growth media and simplifying antimicrobial...
Production of some antimicrobial peptides by bacterial producers is a resource-intensive process, thus, using inexpensive growth media and simplifying antimicrobial extraction and down-stream processing are highly desirable. Acid whey, a dairy industry waste, is explored as a medium for production of broad-spectrum antimicrobials from selected bacteriocinogenic bacteria. Neutralized and yeast extract-supplemented acid whey was suitable for production of antimicrobials by four tested strains, but OSY-EC was the most prolific antimicrobial producer. Concentrating synthesized antimicrobials during culture incubation using beads of polymeric adsorbent resin, followed by solvent extraction and freeze-drying, resulted in antimicrobials-rich powder (AMRP). Under these conditions, OSY-EC produced paenibacillin, polymyxin E, and fusaricidin, which are active against Gram-positive and Gram-negative bacteria and fungi, respectively. When media containing 2x and 4x minimum inhibitory concentrations of AMRP were inoculated with and , microbial populations decreased by ≥4-log CFU ml in tryptic soy broth and ≥3.5-log CFU ml in milk. The antimicrobial mechanism of action of AMRP solutions was attributed to the disruption of cytoplasmic membrane of indicator strains, and . These findings exemplify promising strategies for valorization of acid whey microbial bioreactions to yield potent antimicrobials.
PubMed: 35646844
DOI: 10.3389/fbioe.2022.869778 -
Scientific Reports Sep 2022Pectin is one of the main structural components in fruits and an indigestible fiber made of D-galacturonic acid units with α (1-4) linkage. This study investigates the...
Pectin is one of the main structural components in fruits and an indigestible fiber made of D-galacturonic acid units with α (1-4) linkage. This study investigates the microbial degradation of pectin in apple waste and the production of bioactive compounds. Firstly, pectin-degrading bacteria were isolated and identified, then pectinolytic activity was assessed by DNS. The products were evaluated by TLC and LC-MS-ESI. The antioxidative effects were investigated using DPPH and anti-cancer effects and cytotoxicity were analyzed by MTT and flow cytometry. In this study two new bacterial isolates, Alcaligenes faecalis AGS3 and Paenibacillus polymyxa S4 with the pectinolytic enzyme were introduced. Structure analysis showed that the products of enzymatic degradation include unsaturated mono, di, tri, and penta galacturonic acids with 74% and 69% RSA at 40 mg/mL for A. faecalis and P. polymyxa S4, respectively. The results of anti-tumor properties on MCF-7 cells by MTT assay, for products of AGS3 and S4 at 40 mg/mL after 48 h, showed 7% and 9% survival, respectively. In the flow cytometric assessment, the compounds of AGS3 at 40 mg/mL were 100% lethal in 48 h and regarding S4 isolate caused 98% death. Cytotoxicity evaluation on L-929 cells showed no significant toxicity on living cells.
Topics: Alcaligenes faecalis; Hexuronic Acids; Malus; Paenibacillus; Paenibacillus polymyxa; Pectins; Polygalacturonase
PubMed: 36138114
DOI: 10.1038/s41598-022-20011-2 -
Frontiers in Plant Science 2022The root-knot nematode, , is a major pest in tomato production. , which is primarily found in soil and colonizing roots, is considered a successful biocontrol organism...
The root-knot nematode, , is a major pest in tomato production. , which is primarily found in soil and colonizing roots, is considered a successful biocontrol organism against many pathogens. To evaluate the biocontrol capacity of LMG27872 against in tomato, experiments were conducted both and . A dose-response effect [30, 50, and 100% (10 CFU/mL)] of bacterial suspensions (BSs) on growth and tomato susceptibility to with soil drenching as a mode of application was first evaluated. The results show that the biological efficacy of LMG27872 against parasitism in tomato was dose-dependent. A significantly reduced number of galls, egg-laying females (ELF), and second-stage juveniles (J2) were observed in BS-treated plants, in a dose-dependent manner. The effect of on tomato growth was also dose-dependent. A high dose of BSs had a negative effect on growth; however, this negative effect was not observed when the BS-treated plants were challenged with , indicating tolerance or a defense priming mechanism. In subsequent experiments, the direct effect of BSs was evaluated on J2 mortality and egg hatching of . The effect of BS on J2 mortality was observed from 12 to 24 h, whereby J2 was significantly inhibited by the BS treatment. The effect of on egg hatching was also dependent on the BS dose. The results show a potential of LMG27872 to protect plants from nematode parasitism and its implementation in integrated nematode management suitable for organic productions.
PubMed: 36186028
DOI: 10.3389/fpls.2022.961085 -
Microbiological Research Jul 2021The diseases caused by phytopathogens account for huge economic losses in the agricultural sector. Paenibacillus polymyxa is one of the agriculturally important...
The diseases caused by phytopathogens account for huge economic losses in the agricultural sector. Paenibacillus polymyxa is one of the agriculturally important biocontrol agents and plant growth promoting bacterium. This study describes the antifungal potential of P. polymyxa HK4 against an array of fungal phytopathogens and its ability to stimulate seed germination of cumin and groundnut under in vitro conditions. The cumin and groundnut seeds bacterized with HK4 exhibited enhanced germination efficiency in comparison to controls. The use of HK4 as a soil inoculant significantly promoted the shoot length and fresh weight of groundnut plants in pot studies. The draft genome analysis of HK4 revealed the genetic attributes for motility, root colonization, antagonism, phosphate solubilization, siderophore production and production of volatile organic compounds. The bacterium HK4 harnessed several hydrolytic enzymes that may assist its competence in the rhizosphere. The PCR amplification and sequence analysis of the conserved region of the fusA gene amplicon revealed the ability of HK4 to produce fusaricidin. Furthermore, the LC-ESI-MS/MS of crude cell pellet extract of HK4 confirmed the presence of fusaricidin as a major antifungal metabolite. This study demonstrated the potential of HK4 as a biocontrol agent and a plant growth promoter.
Topics: Antifungal Agents; Bacterial Proteins; Crop Protection; Cuminum; Depsipeptides; Fungi; Genome, Bacterial; Genomics; Mass Spectrometry; Paenibacillus polymyxa; Phylogeny; Plant Diseases; Plant Roots; Plant Shoots
PubMed: 33690069
DOI: 10.1016/j.micres.2021.126734 -
Microorganisms Mar 2023Polymyxin-producing bacteria within the complex have broad-spectrum activities against fungi and bacteria. Their antibacterial activities against soft rot and...
Polymyxin-producing bacteria within the complex have broad-spectrum activities against fungi and bacteria. Their antibacterial activities against soft rot and phytopathogens containing multiple polymyxin-resistant genes were not clear. Here, we selected nine strains within the complex having broad-spectrum antagonistic activities against phytopathogenic fungi and a polymyxin-resistant strain causing stem and root rot disease of sweet potato and did antagonistic assays on nutrient agar and sweet potato tuber slices. These strains within the complex showed clear antagonistic activities against in vitro and in vivo. The most effective antagonistic strain ShX301 showed broad-spectrum antagonistic activities against all the test and strains, completely eliminated from sweet potato seed tubers, and promoted the growth of sweet potato seedlings. Cell-free culture filtrate of ShX301 inhibited growth, swimming motility, and biofilm formation and disrupted plasma membranes, releasing nucleic acids and proteins. Multiple lipopeptides produced by ShX301 may play a major role in the bactericidal and bacteriostatic actions. This study clarifies that the antimicrobial spectrum of polymyxin-producing bacteria within the complex includes the polymyxin-resistant and phytopathogens and strengthens the fact that bacteria within the complex have high probability of being effective biocontrol agents and plant growth promoters.
PubMed: 37110240
DOI: 10.3390/microorganisms11040817