Bacillus is well known for producing a wide range of compounds that inhibit microbial phytopathogens. From this perspective, we were interested in evaluating the biocontrol potential of 5 plant growth-promoting rhizobacteria Bacillus species (PGPR-Bacillus) on 21 microbial pectinolytic plant pathogens isolated from previous studies. Phytopathogenicity and in vivo biocontrol potential of PGPR curative and preventive treatments were investigated from this angle. Overall, the pathogenicity test on healthy tomato, zucchini, and mandarin showed low rot to no symptoms for all PGPR strain culture treatments. Conversely, zucchini pre-treated with PGPR strains B. circulans and B. cereus for 72 h showed no signs of soft rot and remained healthy when in vitro contaminated with phytopathogens (Neisseria cinerea and Pichia anomala). Additionally, the PGPR-Bacillus strains were shown to be effective in mitigating the symptoms of soft rot in tomatoes, zucchini, and oranges using in vivo curative treatment. It is true that the majority of pectinolytic phytopathogenic strains exhibited antibiotic resistance. In vivo tests revealed that PGPR-Bacillus cell culture was effective against plant pathogens. Thus, PGPR-Bacillus can be considered a potential biocontrol agent for pectinolytic plant pathogens.
- MeSH
- antibióza * MeSH
- Bacillus * fyziologie MeSH
- biologická kontrola škůdců * metody MeSH
- biologická ochrana * MeSH
- Citrus mikrobiologie růst a vývoj MeSH
- nemoci rostlin * mikrobiologie prevence a kontrola MeSH
- pektiny metabolismus MeSH
- půdní mikrobiologie MeSH
- Solanum lycopersicum mikrobiologie růst a vývoj MeSH
- vývoj rostlin MeSH
- Publikační typ
- časopisecké články MeSH
The present study has undertaken the isolation of marine yeasts from mangrove sediment samples and their ability to produce alkaline protease enzymes. A total of 14 yeast isolates were recovered on yeast-malt agar (YMA) and yeast extract peptone dextrose (YEPD) agar medium. After screening for proteolytic activity on skim milk agar, marine yeast isolate, AKB-1 exhibited a hydrolysis zone of 18 mm. Optimal conditions for the enzyme production from yeast isolate AKB-1 were at 30 °C, pH 8, fructose as carbon source, potassium nitrate as nitrogen source, and 25% saline concentration. Under the optimal conditions, the protease enzyme activity of the isolate AKB-1 was observed to be 978 IU/mL. The structural and functional analysis was carried out through FTIR and HPLC analysis for the extracted protease enzyme. Furthermore, the enzyme produced was partially purified by solvent extraction using ethyl acetate and ammonium sulfate precipitation (3.4-fold) followed by dialysis (56.8-fold). The molecular weight of the purified enzyme was observed to be around 60 kDa using SDS-PAGE. The extracted protein showed good antibacterial activity against six different clinical bacterial pathogens and the highest against Bacillus cereus (16 ± 0.5 mm). The extracted protease enzyme was revealed to remove blood stains from cloth within 20 min of application similar to the commercial detergent. The marine yeast isolate was further identified as Candida orthopsilosis AKB-1 (Accession number KY348766) through 18S rRNA sequencing, and a phylogenetic tree was generated.
- MeSH
- antibakteriální látky farmakologie metabolismus chemie izolace a purifikace MeSH
- Bacillus cereus účinky léků MeSH
- bakteriální proteiny * chemie farmakologie metabolismus izolace a purifikace MeSH
- Candida * enzymologie izolace a purifikace genetika klasifikace MeSH
- endopeptidasy * chemie metabolismus izolace a purifikace farmakologie MeSH
- fylogeneze MeSH
- geologické sedimenty mikrobiologie MeSH
- koncentrace vodíkových iontů MeSH
- kultivační média chemie MeSH
- mikrobiální testy citlivosti MeSH
- molekulová hmotnost MeSH
- stabilita enzymů MeSH
- teplota MeSH
- Publikační typ
- časopisecké články MeSH
The largest obstacle in the promotion of biopesticides is the existence of counterfeit products available in the market. Identification and quantification of antagonistic organisms in biopesticide products are the key to the reduction of spurious microbial pesticides. In this study, we have developed a simple, sensitive, isothermal-based colourimetric assay for specific detection of Bacillus subtilis from the biopesticide formulations and soil samples. A region specific to B. subtilis which codes for shikimate dehydrogenase was identified through in silico analysis. We employed conventional PCR, loop-mediated isothermal amplification (LAMP), recombinase polymerase amplification (RPA), and qPCR for specific detection of B. subtilis in soil samples and biopesticide formulations. Specificity tests showed that the PCR primers amplified an amplicon of 521 bp in four strains of B. subtilis only, and no amplification was found in negative control samples. Similarly, the LAMP assay showed sky blue colour in all four strains of B. subtilis and violet colour in negative control samples. Whereas in the RPA assay, upon the addition of SYBR Green dye, a bright green colour was seen in B. subtilis strains, while a brick-red colour was observed in negative control samples by visualizing under a UV transilluminator. The qPCR assay showed specific amplifications with a Ct value of 12 for B. subtilis strains and no amplification in negative control samples. In the sensitivity test, PCR could amplify DNA of B. subtilis up to 500 pg/μL. DNA concentration as low as 10 pg/μL was enough to show the colour change in the LAMP as well as the RPA assays, whereas the qPCR assay showed sensitivity till 100 pg/μL. All four diagnostic assays developed in the study have been validated in soil samples and B. subtilis-based biopesticides. Compared to conventional PCR, the qPCR assay has the advantage of quantification and visualizing the result in real-time, whereas LAMP and RPA assays have the benefits of being colourimetric and less time-consuming. The other advantages are that the results can be visualized with the naked eye, and these assays do not require a costly thermal cycler and gel documentation system. Hence, LAMP and RPA assays are highly suitable for developing point-of-need diagnostic kits and, in turn, help regulators assess the quality of biopesticides in the market.
- MeSH
- alkoholoxidoreduktasy * genetika MeSH
- Bacillus subtilis * genetika izolace a purifikace enzymologie MeSH
- bakteriální proteiny genetika MeSH
- diagnostické techniky molekulární * metody MeSH
- kolorimetrie * metody MeSH
- kvantitativní polymerázová řetězová reakce MeSH
- půdní mikrobiologie MeSH
- senzitivita a specificita MeSH
- techniky amplifikace nukleových kyselin * metody MeSH
- Publikační typ
- časopisecké články MeSH
Biopriming seeds with beneficial bacteria has potential to enhance seed germination. Therefore, in this investigation, five sulphur-oxidizing bacterial cultures, viz., Pantoea dispersa SOB2, Bacillus velezensis SN06, Bacillus cereus SN20, Bacillus tropicus SN16, and Bacillus megaterium SN11, were evaluated for different plant growth-promoting traits and their impact on Vigna radiata L. (mung bean) and Brassica juncea L. (mustard) seed germination. Among these, three bacterial cultures Pantoea dispersa SOB2, Bacillus velezensis SN06, and Bacillus megaterium SN11 evinced potential for mineral solubilization on solid medium where Pantoea dispersa SOB2 had the maximum solubilization indices-3.06, 5.14, and 2.48 for phosphate, zinc, and potassium respectively. The culture also displayed higher indole acetic acid (113.12 μg/mL), gibberellic acid (162.66 μg/mL), ammonia (5.23 μg/mL), and siderophore (69.53%) production than other bacterial cultures whereas Bacillus cereus SN20 showed maximum exopolysaccharide production (9.26 g/L). Bacterial culture Pantoea dispersa SOB2 significantly ameliorated the germination rate (3.73 no./day) and relative seed germination (208%) of Brassica juncea L., while Bacillus velezensis SN06 and Bacillus cereus SN20 followed with germination rate and relative seed germination of 2.86 no./day and 207%, respectively. Pantoea dispersa SOB2 displayed lowest mean germination time 2.91 days followed by Bacillus megaterium SN11 with 3.19 days. Biopriming with sulphur-oxidizing bacterial cultures, germination parameters of Vigna radiata L. were also markedly improved. Pantoea dispersa SOB2 demonstrated the highest germination rate (6.72 no./day), relative seed germination (115.56%), and minimum mean generation time (1.73 days). Bacillus velezensis SN06 inoculation had a beneficial effect on the seedling growth of Vigna radiata L., whereas Pantoea dispersa SOB2 greatly aided the seedling growth of Brassica juncea L. Results corroborated a prominent positive correlation between seed germination and plant growth-promoting traits. This is the first study on Pantoea dispersa as sulphur oxidizer, displaying plant growth promoting traits and seed germination potential. The potent sulphur-oxidizing bacterial cultures possessing plant growth promoting activities enhanced seed germination under in vitro conditions that could be further explored in field as biofertilizers to enhance the growth and yield of Brassica juncea L. and Vigna radiata L. crop.
- MeSH
- Bacillus * metabolismus MeSH
- Bacteria * metabolismus MeSH
- hořčice rodu Brassica * růst a vývoj mikrobiologie MeSH
- klíčení * MeSH
- kyseliny indoloctové metabolismus MeSH
- oxidace-redukce MeSH
- Pantoea metabolismus MeSH
- regulátory růstu rostlin metabolismus MeSH
- semena rostlinná * mikrobiologie růst a vývoj MeSH
- síra * metabolismus MeSH
- vigna * růst a vývoj mikrobiologie MeSH
- Publikační typ
- časopisecké články MeSH
Cíl: Používání filtroventrilačních systémů v městských autobusech ve vyspělých zemích zvyšuje komfort a kvalitu vnitřního ovzduší v prostředcích pozemní dopravy. Mikrobiální kontaminace byla studována na výstupních a vstupních plochách 5 vzduchových filtrů vyjmutých z klimatizačního systému městských autobusů při pravidelné údržbě. Materiál a metodika: K získání vzorků z výstupní i vstupní strany filtrů byla použita technika suchého stěru. Kultivace byla provedena na různých selektivních nebo selektivně-diagnostických půdách pro kultivaci životaschopných bakterií. K identifikaci bakteriálních druhů bylo použito barvení podle Grama a imerzní mikroskopie. Vybrané kolonie byly rovněž podrobeny proteomické studii. Po identifikaci byly bakterie kvantifikovány. Výsledky: Na vstupním i výstupním povrchu filtrů převažovaly bakterie rodu Bacillus – Bacillus cereus, Bacillus subtilis, Bacillus licheniformis, Bacillus pumilus, Bacillus flexus. Identifikovány byli také bakterie rodů Staphylococcus, Brevibacillus, Peribacillus a Paenibacillus. Kvantifikace ukázala nízkou kontaminaci výstupních povrchů filtrů 1 a 2. Kontaminace vstupní a výstupní strany filtrů 3, 4 a 5 a odhalila téměř stejnou kontaminaci vstupních a výstupních ploch. Závěry: Podle nalezených výsledků doporučujeme buď častější výměnu filtrů, nebo volbu filtrů s nižší porozitou.
The use of HVAC in urban buses in developed countries increases the comfort and indoor air quality in the means of ground transportation. The microbial contamination was studied on outlet and inlet surfaces of 5 air filters removed from the urban buses HVAC during regular maintenance. To acquire samples from both the outlet and the inlet sides of the filters, dry swabbing technique was used. Cultivation was performed on different selective or selective-diagnostic agars, to cultivate viable bacteria. To identify the bacterial species, Gram stain and immerse microscopy was used. Selected colonies underwent the proteomic study (MALDI-TOF) as well. After identification, bacteria were quantified. The bacteria of the genus Bacillus – Bacillus cereus, Bacillus subtilis, Bacillus licheniformis, Bacillus pumilus, Bacillus flexus prevailed on both inlet and outlet surfaces of the filters. The members of genera Staphylococcus, Brevibacillus, Peribacillus or Paenibacillus were also identified. The quantification of colony forming units showed low contamination of the outlet surfaces of filters 1 and 2. The contamination of inlet and outlet sides of filters 3, 4, and 5 was comparable, revealed nearly the same contamination of inlet and outlet surfaces. In the case of filters 3, 4 and 5 we recommend more frequent filter changing or more efficient filter choice.
CssRS is a two-component system that plays a pivotal role in mediating the secretion stress response in Bacillus subtilis. This system upregulates the synthesis of membrane-bound HtrA family proteases that cope with misfolded proteins that accumulate within the cell envelope as a result of overexpression or heat shock. Recent studies have shown the induction of CssRS-regulated genes in response to cell envelope stress. We investigated the induction of the CssRS-regulated htrA promoter in the presence of different cell wall- and membrane-active substances and observed induction of the CssRS-controlled genes by glycopeptides (vancomycin and teicoplanin), polymyxins B and E, certain β-lactams, and detergents. Teicoplanin was shown to elicit remarkably stronger induction than vancomycin and polymyxin B. Teicoplanin and polymyxin B induced the spxO gene expression in a CssRS-dependent fashion, resulting in increased activity of Spx, a master regulator of disulfide stress in Bacillus subtilis. The CssRS signaling pathway and Spx activity were demonstrated to be involved in Bacillus subtilis resistance to teicoplanin and polymyxin B.
- MeSH
- antibakteriální látky * farmakologie MeSH
- Bacillus subtilis * genetika účinky léků metabolismus MeSH
- bakteriální proteiny * genetika metabolismus MeSH
- polymyxin B * farmakologie MeSH
- promotorové oblasti (genetika) MeSH
- regulace genové exprese u bakterií * účinky léků MeSH
- signální transdukce MeSH
- teikoplanin * farmakologie MeSH
- Publikační typ
- časopisecké články MeSH
Antibiotic resistance is one of the biggest threats to global health. Fungal endophytes are important sources of active natural products with antimicrobial potential. The purpose of this study was to characterize the endophytes coexisting with Helichrysum oocephalum, evaluate their antimicrobial activities, and annotate the endophytes metabolites. Six fungal species, including Fusarium avenaceum and Fusarium tricinctum, were identified. Endophytes were cultured, and their metabolites were extracted. The antimicrobial effects of the extracts were tested against Staphylococcus aureus, Bacillus cereus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans. In addition, anti-biofilm effects of the extracts were examined against P. aeruginosa and S. epidermidis. The metabolites in the most active extract were annotated on the basis of the LC-ESI-QToF-MS/MS data. In anti-biofilm studies, F. avenaceum extract was effective in destroying and inhibiting the biofilm formation of S. epidermidis. LC-MS analysis showed that most of the identified compounds in the active extracts were enniatins (cyclic hexadepsipeptides). However, apicidin derivatives were also annotated. Our results revealed that these endophytes, especially Fusarium species, have antimicrobial activity against S. aureus, B. cereus, and C. albicans and anti-biofilm activity against S. epidermidis. According to the literature, the observed antimicrobial activity can be attributed to the enniatins. However, further phytochemical and pharmacological studies are necessary in this regard.
- MeSH
- antibakteriální látky * farmakologie izolace a purifikace chemie MeSH
- antifungální látky * farmakologie izolace a purifikace chemie MeSH
- antiinfekční látky * farmakologie izolace a purifikace chemie MeSH
- Bacillus cereus účinky léků MeSH
- biofilmy účinky léků MeSH
- Candida albicans účinky léků MeSH
- endofyty * chemie metabolismus izolace a purifikace MeSH
- Escherichia coli účinky léků MeSH
- Fusarium * chemie metabolismus MeSH
- mikrobiální testy citlivosti MeSH
- Pseudomonas aeruginosa účinky léků MeSH
- Staphylococcus aureus účinky léků MeSH
- Staphylococcus epidermidis účinky léků MeSH
- tandemová hmotnostní spektrometrie MeSH
- Publikační typ
- časopisecké články MeSH
Microbial entomopathogens that include fungi, bacteria, viruses, and nematodes have long been valued for their role in biological control of insect pests. However, recent research highlights their expanded applications beyond pest management. Entomopathogenic fungi such as Beauveria bassiana and Metarhizium spp. are increasingly recognized for their potential as biocontrol agents in integrated pest management systems. These fungi exhibit not only direct insecticidal effects but also secondary metabolites that contribute to plant disease suppression, thereby enhancing crop health and yield. Bacterial entomopathogen Bacillus thuringiensis, as the most widely used biopesticide, has also demonstrated potency not only against insects but also as systemic resistance inducer, thereby boosting plant immunity against pathogens. Moreover, entomopathogens are emerging as growth promoters and biostimulants, enhancing crop vigor through nutrient uptake and root development. This review consolidates current knowledge on the mechanisms of action of microbial entomopathogens against pests as well as current understanding on its other plant-beneficial traits. It also discusses their environmental impact and potential integration into sustainable agricultural practices. This comprehensive exploration underscores the transformative potential of microbial entomopathogens in shaping future strategies for holistic crop health management including pest management in agriculture.
- MeSH
- Bacillus thuringiensis MeSH
- Bacteria MeSH
- Beauveria MeSH
- biologická kontrola škůdců * metody MeSH
- biologická ochrana * MeSH
- hmyz mikrobiologie MeSH
- houby * MeSH
- Metarhizium fyziologie MeSH
- nemoci rostlin prevence a kontrola parazitologie mikrobiologie MeSH
- zemědělské plodiny mikrobiologie růst a vývoj MeSH
- zemědělství * metody MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Bacillus thuringiensis (Bt) is known for its Cry and Vip3A pesticidal proteins with high selectivity to target pests. Here, we assessed the potential of a novel neotropical Bt strain (UFT038) against six lepidopteran pests, including two Cry-resistant populations of fall armyworm, Spodoptera frugiperda. We also sequenced and analyzed the genome of Bt UFT038 to identify genes involved in insecticidal activities or encoding other virulence factors. In toxicological bioassays, Bt UFT038 killed and inhibited the neonate growth in a concentration-dependent manner. Bt UFT038 and HD-1 were equally toxic against S. cosmioides, S. frugiperda (S_Bt and R_Cry1 + 2Ab populations), Helicoverpa zea, and H. armigera. However, larval growth inhibition results indicated that Bt UFT038 was more toxic than HD-1 to S. cosmioides, while HD-1 was more active against Chrysodeixis includens. The draft genome of Bt UFT038 showed the cry1Aa8, cry1Ac11, cry1Ia44, cry2Aa9, cry2Ab35, and vip3Af5 genes. Besides this, genes encoding the virulence factors (inhA, plcA, piplC, sph, and chi1-2) and toxins (alo, cytK, hlyIII, hblA-D, and nheA-C) were also identified. Collectively, our findings reveal the potential of the Bt UFT038 strain as a source of insecticidal genes against lepidopteran pests, including S. cosmioides and S. frugiperda.
- MeSH
- Bacillus thuringiensis * genetika metabolismus MeSH
- bakteriální proteiny genetika metabolismus MeSH
- biologická kontrola škůdců MeSH
- endotoxiny metabolismus MeSH
- faktory virulence metabolismus MeSH
- Glycine max MeSH
- hemolyziny genetika metabolismus farmakologie MeSH
- insekticidy * farmakologie metabolismus MeSH
- larva MeSH
- lidé MeSH
- můry * MeSH
- novorozenec MeSH
- Spodoptera metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- novorozenec MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Biofilm formation is an effective survival strategy of plant-associated microorganisms in hostile environments, so the application of biofilm-forming and exopolysaccharide (EPS)-producing beneficial microbes to plants has received more attention in recent years. This study examined the ability of biofilm and EPS production of Bacillus subtilis and Bacillus thuringiensis strains under different NaCl concentrations (0, 50, 100, 200, and 400 mmol/L), pH values (5.5, 6.5, 7.5, and 8.5), and phosphate levels (0, 25, 50, and 100 mmol/L at 0 and 400 mmol/L NaCl). B. subtilis BS2 and B. thuringiensis BS6/BS7 strains significantly increased biofilm formation in a similar pattern to EPS production under salt stress. B. subtilis BS2/BS3 enhanced biofilm production at slightly acidic pH with a lower EPS production but the other strains formed considerably more amount of biofilm and EPS at alkaline pH. Interestingly, higher levels of phosphate substantially decreased biofilm and EPS production at 0 mmol/L NaCl but increased biofilm formation at 400 mmol/L salt concentration. Overall, contrary to phosphate, salt and pH differently influenced biofilm and EPS production by Bacillus strains. EPS production contributed to biofilm formation to some extent under all the conditions tested. Some Bacillus strains produced more abundant biofilm under salt and pH stress, indicating their potential to form in vivo biofilms in rhizosphere and on plants, particularly under unfavorable conditions.
- MeSH
- Bacillus subtilis fyziologie metabolismus účinky léků MeSH
- Bacillus thuringiensis fyziologie účinky léků MeSH
- bakteriální polysacharidy * metabolismus biosyntéza MeSH
- biofilmy * účinky léků růst a vývoj MeSH
- chlorid sodný * farmakologie metabolismus MeSH
- fosfáty * metabolismus farmakologie MeSH
- koncentrace vodíkových iontů MeSH
- Publikační typ
- časopisecké články MeSH
