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Microbiology Spectrum Sep 2021Bacillus mycoides is poorly known despite its frequent occurrence in a wide variety of environments. To provide direct insight into its ecology and evolutionary history,...
Bacillus mycoides is poorly known despite its frequent occurrence in a wide variety of environments. To provide direct insight into its ecology and evolutionary history, a comparative investigation of the species pan-genome and the functional gene categorization of 35 isolates obtained from soil samples from northeastern Poland was performed. The pan-genome of these isolates is composed of 20,175 genes and is characterized by a strong predominance of adaptive genes (∼83%), a significant amount of plasmid genes (∼37%), and a great contribution of prophages and insertion sequences. The pan-genome structure and phylodynamic studies had suggested a wide genomic diversity among the isolates, but no correlation between lineages and the bacillus origin was found. Nevertheless, the two B. mycoides populations, one from Białowieża National Park, the last European natural primeval forest with soil classified as organic, and the second from mineral soil samples taken in a farm in Jasienówka, a place with strong anthropogenic pressure, differ significantly in the frequency of genes encoding proteins enabling bacillus adaptation to specific stress conditions and production of a set of compounds, thus facilitating their colonization of various ecological niches. Furthermore, differences in the prevalence of essential stress sigma factors might be an important trail of this process. Due to these numerous adaptive genes, B. mycoides is able to quickly adapt to changing environmental conditions. This research allows deeper understanding of the genetic organization of natural bacterial populations, specifically, Bacillus mycoides, a psychrotrophic member of the Bacillus cereus group that is widely distributed worldwide, especially in areas with continental cold climates. These thorough analyses made it possible to describe, for the first time, the B. mycoides pan-genome, phylogenetic relationship within this species, and the mechanisms behind the species ecology and evolutionary history. Our study indicates a set of functional properties and adaptive genes, in particular, those encoding sigma factors, associated with B. mycoides acclimatization to specific ecological niches and changing environmental conditions.
Topics: Anthropogenic Effects; Bacillus; Biological Evolution; DNA Transposable Elements; Ecology; Genome, Bacterial; Genomics; High-Throughput Nucleotide Sequencing; Phylogeny; Plasmids; Sigma Factor; Soil; Soil Microbiology; Species Specificity
PubMed: 34287030
DOI: 10.1128/Spectrum.00311-21 -
Life (Basel, Switzerland) Jan 2022Soil salinity is one of the abiotic constraints that imbalance nutrient acquisition, hampers plant growth, and leads to potential loss in agricultural productivity....
Soil salinity is one of the abiotic constraints that imbalance nutrient acquisition, hampers plant growth, and leads to potential loss in agricultural productivity. Salt-tolerant plant growth-promoting rhizobacteria (PGPR) can alleviate the adverse impacts of salt stress by mediating molecular, biochemical, and physiological status. In the present study, the bacterium PM35 showed resistance up to 3 M NaCl stress and exhibited plant growth-promoting features. Under salinity stress, the halo-tolerant bacterium PM35 showed significant plant growth-promoting traits, such as the production of indole acetic acid, siderophore, ACC deaminase, and exopolysaccharides. Inoculation of PM35 alleviated salt stress in plants and enhanced shoot and root length under salinity stress (0, 300, 600, and 900 mM). The PM35 alleviated salinity stress by enhancing the photosynthetic pigments, carotenoids, radical scavenging capacity, soluble sugars, and protein content in inoculated maize plants compared to non-inoculated plants. In addition, PM35 significantly boosted antioxidant activities, relative water content, flavonoid, phenolic content, and osmolytes while reducing electrolyte leakage, HO, and MDA in maize compared to control plants. Genes conferring abiotic stress tolerance ( and genes) were amplified in PM35. Moreover, all reactions are accompanied by the upregulation of stress-related genes (APX and SOD). Our study reveals that PM35 is capable of promoting plant growth and increasing agricultural productivity.
PubMed: 35207506
DOI: 10.3390/life12020219 -
Journal of the Science of Food and... Aug 2020Avocado is affected by Colletotrichum gloeosporioides causing anthracnose. Antagonistic microorganisms against C. gloeosporioides represent an alternative for biological...
BACKGROUND
Avocado is affected by Colletotrichum gloeosporioides causing anthracnose. Antagonistic microorganisms against C. gloeosporioides represent an alternative for biological control. Accordingly, in the present study, we focused on the isolation and characterization of potential antagonist bacteria against a member of the C. gloeosporioides species complex with respect to their possible future application.
RESULTS
Samples of avocado rhizospheric soil were aquired from an orchard located in Ocuituco, Morelos, Mexico, aiming to obtain bacterial isolates with potential antifungal activity. From the soil samples, 136 bacteria were isolated and they were then challenged against a member of the C. gloeosporioides species complex; only three bacterial isolates A1, A2 and A3 significantly diminished mycelial fungal growth by 75%, 70% and 60%, respectively. Two of these isolates were identified by 16S rRNA as Bacillus mycoides (A1 and A2) and the third was identified as Bacillus tequilensis (A3). Bacillus mycoides bacterial cell-free supernatant reduced the mycelial growth of a member of the C. gloeosporioides species complex isolated from avocado by 65%, whereas Bacillus tequilensis A3 supernatant did so by 25% after 3 days post inoculation. Bacillus tequilensis mycoides A1 was a producer of proteases, indolacetic acid and siderophores. Preventive treatment using a cell-free supernatant of B. mycoides A1 diminished the severity of anthracnose disease (41.9%) on avocado fruit.
CONCLUSION
These results reveal the possibility of using B. mycoides A1 as a potential biological control agent. © 2020 Society of Chemical Industry.
Topics: Antibiosis; Bacillus; Colletotrichum; Mexico; Mycelium; Persea; Plant Diseases; Siderophores; Soil Microbiology
PubMed: 32338377
DOI: 10.1002/jsfa.10450 -
Journal of Applied Microbiology Feb 2022To analyse effects and mechanisms of plant growth promotion mediated by Bacillus mycoides strain A3 (BmA3), in Arabidopsis thaliana seedlings.
Rhizobacterial Bacillus mycoides functions in stimulating the antioxidant defence system and multiple phytohormone signalling pathways to regulate plant growth and stress tolerance.
AIMS
To analyse effects and mechanisms of plant growth promotion mediated by Bacillus mycoides strain A3 (BmA3), in Arabidopsis thaliana seedlings.
METHODS AND RESULTS
Bacillus mycoides strain A3 (BmA3) isolated from the bamboo rhizosphere produced phytohormones, including indole-3-acetic acid (IAA) and gibberellic acid (GA), and exhibited phosphate solubilization and radical scavenging activities. A. thaliana seedlings inoculated with BmA3 exhibited an altered root architecture including an increased number of lateral roots and root hairs. Likewise, enhanced photosynthetic efficiency through the accumulation of higher levels of chlorophyll and starch, and increased plant size and fresh weight were observed in the BmA3-treated seedlings. This bacterial inoculation stimulated the antioxidant defence system by increasing the activities of catalase (CAT), guaiacol peroxidase (GPX), ascorbate peroxidase (APX) and phenylalanine ammonia-lyase (PAL). Secondary metabolites, including phenolic compounds, flavonoids and glucosinolates, were induced to higher levels in the BmA3-treated plants. Under drought and heat stresses, lower levels of H O , malondialdehyde (MDA) and electrolyte leakage were noticed in the treated seedlings. Genes involved in the signalling pathway of jasmonic acid (JA) including MYC2 and lipoxygenase 1 (LOX1) and salicylic acid (SA) including SAR DEFICIENT 1 (SARD1) and CAM-BINDING PROTEIN 60-LIKE G (CBP60G), and the antioxidant defence system including Ascorbate peroxidase (AtAPX) and alternative oxidase (AOX) were upregulated in BmA3-treated plants. Moreover, pathogenesis-related protein 1 (PR-1) and PR-2, marker genes for disease resistance, as well as DREB2A and HsFA2, which function in abiotic stress regulation, were also upregulated.
CONCLUSIONS
BmA3 was able to activate JA and SA signalling pathways to induce plant growth and abiotic stress tolerance in A. thaliana seedlings.
SIGNIFICANCE AND IMPACT OF STUDY
The plant growth promotion and increased stress tolerance induced by BmA3 were the result of the combined effects of microbial metabolites and activated host plant responses, including phytohormone signalling pathways and antioxidant defence systems.
Topics: Antioxidants; Bacillus; Plant Development; Plant Growth Regulators; Seedlings; Stress, Physiological
PubMed: 34365711
DOI: 10.1111/jam.15252 -
Frontiers in Microbiology 2022Horizontal gene transfer (HGT) is a major driving force in shaping bacterial communities. Key elements responsible for HGT are conjugation-like events and transmissible... (Review)
Review
Horizontal gene transfer (HGT) is a major driving force in shaping bacterial communities. Key elements responsible for HGT are conjugation-like events and transmissible plasmids. Conjugative plasmids can promote their own transfer as well as that of co-resident plasmids. and relatives harbor a plethora of plasmids, including conjugative plasmids, which are at the heart of the group species differentiation and specification. Since the first report of a conjugation-like event between strains of () 40 years ago, many have studied the potential of plasmid transfer across the group, especially for plasmids encoding major toxins. Over the years, more than 20 plasmids from isolates have been reported as conjugative. However, with the increasing number of genomic data available, analyses indicate that more plasmids from genomes present self-transfer potential. bacteria occupy diverse environmental niches, which were mimicked in laboratory conditions to study conjugation-related mechanisms. Laboratory mating conditions remain nonetheless simplistic compared to the complex interactions occurring in natural environments. Given the health, economic and ecological importance of strains of , it is of prime importance to consider the impact of conjugation within this bacterial group.
PubMed: 36406448
DOI: 10.3389/fmicb.2022.1034440 -
The Netherlands Journal of Medicine Aug 2019A 65-year-old male was admitted to the Intensive Care Unit after being resuscitated because of a hypoxic cardiac arrest caused by influenza. Blood cultures taken at time...
A 65-year-old male was admitted to the Intensive Care Unit after being resuscitated because of a hypoxic cardiac arrest caused by influenza. Blood cultures taken at time of admission surprisingly grew Bacillus mycoides, a spore-producing apathogenic agriculture bacterium. We collected culture samples at his barge. Although we did not culture Bacillus mycoides, we did find multiple other Bacillus species. We hypothesised that our patient was colonised from the freights of his barge, and bloodstream infection occurred during resuscitation with either the bacterium itself or its spores. To our knowledge, this is the first report on bloodstream infection with Bacillus mycoides in a human patient.
Topics: Aged; Agricultural Workers' Diseases; Anti-Bacterial Agents; Bacillus; Blood Culture; Heart Arrest; Humans; Male; Netherlands; Resuscitation; Sepsis; Treatment Outcome; Vancomycin
PubMed: 31391330
DOI: No ID Found -
Microbial Pathogenesis Mar 2020Recently, microbial exopolysaccharides (EPSs) have offered very large field for medical applications owing to their bioactive characteristics. This study aimed to obtain...
Recently, microbial exopolysaccharides (EPSs) have offered very large field for medical applications owing to their bioactive characteristics. This study aimed to obtain antitumor EPS and to optimize its production using different optimization approaches. Eighty EPSs-producing bacteria were obtained from mud samples. Isolate BS4 was selected as the most potent antitumor EPS-producer and identified as Bacillus mycoides BS4 using 16S rRNA gene sequence analysis. Cell viability and antitumor activity of produced EPS were investigated using microscopic examination and MTT assay. Interestingly, the produced EPS exhibited low cytotoxicity against normal cell baby hamster kidney (BHK) with IC at 254 μgml while it exhibited an inhibitory effect against cancer cells of human hepatocellular carcinoma (HepG2) and Colorectal adenocarcinoma cells (Caco-2) with IC of 138 μgml and 159 μgml, respectively. The purified EPS was characterized using Fourier transform infrared, gel permeation chromatography and gas chromatography-mass spectroscopy. It showed molecular weight of 1.90 × 10 Da and consists of galactose, mannose, glucose and glucuronic acid. The factors affecting EPS production were optimized using one-factor-at-a time and statistical optimization methods. The Placket-Burman (PB) design results indicated that sugarcane molasses, peptone and shaking conditions were the most significant variables, which were further optimized by Response Surface Methodology (RSM). The optimum conditions for EPS production were 8.0% (w/v) sugarcane molasses, 6 gL peptone and 300 rpm that produce 8.02gL of EPS. This indicates the potentiality of Bacillus mycoides BS4 for production of EPS with biomedical applications.
Topics: Antineoplastic Agents; Bacillus; Cell Survival; Hep G2 Cells; Humans; Molecular Weight; Polysaccharides, Bacterial
PubMed: 31874230
DOI: 10.1016/j.micpath.2019.103947 -
Chemosphere May 2023Plant growth-promoting rhizobacteria (PGPR) are naturally occurring soil bacteria and are known to induce plant growth promotion and titanium dioxide...
Bacillus mycoides PM35 in combination with titanium dioxide (TiO)⎯nanoparticles enhanced morpho-physio-biochemical attributes in Barley (Hordeum vulgare L.) under cadmium stress.
Plant growth-promoting rhizobacteria (PGPR) are naturally occurring soil bacteria and are known to induce plant growth promotion and titanium dioxide (TiO)⎯nanoparticles (NPs) used in a range of applications that need increased whiteness, improved corrosion resistance and photocatalytic activity. Keeping in view the stress mitigation potential of TiO⎯NPS and B. mycoides PM35, the existing research work was premeditated to inspect the beneficial role of seed priming with using different levels of TiO⎯NPs i.e., [(0 no TiO⎯NPs), 25 and 50 μg/ml] and soil incubation plant growth promoting rhizobacteria (B. mycoides PM35) i.e., [(0 no B. mycoides PM35), 10 and 20 μL] on biochemical, morphological and physiological characteristics of Barley (Hordeum vulgare L.) plants under different levels of Cd in the soil i.e., [(0 Cd), 50 and 100 mg kg]. Results from the present study showed that the increasing levels of Cd in the soil significantly (P < 0.05) decreased plant growth and biomass, photosynthetic pigments, gas exchange attributes, sugars, and nutritional contents from the roots and shoots of the plants. In contrast, increasing levels of Cd in the soil significantly (P < 0.05) increased oxidative stress indicators in term of malondialdehyde, hydrogen peroxide, and electrolyte leakage, and also increased organic acid exudation patter in the roots of H. vulgare. Although, the activities of enzymatic antioxidants and the response of their gene expressions in the roots and shoots of the plants and non-enzymatic such as phenolic, flavonoid, ascorbic acid, and anthocyanin contents were initially increased with the exposure of 50 mg kg Cd, but decreased by the increasing the Cd concentration 100 mg kg in the soil. The negative impact of Cd toxicity can overcome the application of PGPR (B. mycoides PM35) and TiO⎯NPs, which ultimately increased plant growth and biomass by capturing the reactive oxygen species, and decreased oxidative stress in H. vulgare by decreasing the Cd contents in the roots and shoots of the plants. Our results also showed that the TiO⎯NPs were more sever and showed better results when we compared with PGPR (B. mycoides PM35) under the same treatment of Cd in the soil. Research findings, therefore, suggest that the combined application of PGPR (B. mycoides PM35) and TiO⎯NPs can ameliorate Cd toxicity in H. vulgare, resulting in improved plant growth and composition under metal stress, as depicted by balanced exudation of organic acids.
Topics: Cadmium; Hordeum; Antioxidants; Soil; Plant Roots; Soil Pollutants
PubMed: 36828111
DOI: 10.1016/j.chemosphere.2023.138224 -
FEMS Microbiology Letters Apr 2013The Bacillus cereus group comprises seven bacterial species: Bacillus cereus, Bacillus anthracis, Bacillus thuringiensis, Bacillus mycoides, Bacillus pseudomycoides,...
The Bacillus cereus group comprises seven bacterial species: Bacillus cereus, Bacillus anthracis, Bacillus thuringiensis, Bacillus mycoides, Bacillus pseudomycoides, Bacillus cytotoxicus, and Bacillus weihenstephanensis. Bacillus weihenstephanensis is distinguished based on its capability to grow at 7 °C but not at 43 °C, and the presence of specific signature sequences in the 16S rRNA and cspA genes and in several housekeeping genes: glpF, gmK, purH, and tpi. Bacillus weihenstephanensis-specific signature sequences were found in some B. cereus and B. mycoides strains suggesting psychrotolerance. This was confirmed by growth at 7 °C but not at 43 °C. The other B. cereus and B. mycoides strains and all B. anthracis, B. thuringiensis, and B. pseudomycoides harbored the mesophilic signature sequences. The strains tested grew at 43 °C but did not grow at 7 °C. A maximum-likelihood phylogenetic tree was inferred from comparisons of the concatenated nucleotide sequences. Three groups and one branch were revealed. Group I, II, and III comprised the mesophilic B. cereus, some mesophilic B. mycoides, and all B. anthracis and B. thuringiensis strains; the psychrotolerant B. cereus and B. mycoides, and all B. weihenstephanensis strains; and some mesophilic B. mycoides and all B. pseudomycoides strains, respectively. The branch corresponds to the single B. cytotoxicus strain. Based on psychrotolerance and multilocus sequence analysis, further confirmed by comparisons of amino acid sequences, we show that some B. cereus and B. mycoides strains should be reclassified as B. weihenstephanensis.
Topics: Bacillus; Bacillus cereus; Bacterial Proteins; Molecular Sequence Data; Multilocus Sequence Typing; Phylogeny; Sequence Analysis, DNA; Temperature
PubMed: 23413955
DOI: 10.1111/1574-6968.12106 -
Polymers Jul 2022Bioplastics are contemplated as remarkable substitutes for conventional plastics to accommodate green technological advancements. However, their industrial production...
Bioplastics are contemplated as remarkable substitutes for conventional plastics to accommodate green technological advancements. However, their industrial production has not been fully implemented owing to the cost of carbon resources. From another perspective, valorizing different paper mill wastes has become a prominent research topic. These materials may serve as an affording sustainable feedstock for bioplastic production. Adjustment of cardboard waste hydrolysate as suitable fermentation media for production of bacterial polyhydroxyalkanoates (PHAs) has been investigated. Cardboard samples were defibered and dried before enzymatic hydrolysis. The enzymatic degradation of commercial cellulase was monitored over 15 days. Interestingly, 18.2 ± 0.2 g/L glucose yield was obtained from 50 g cardboard samples using a 1.5% (/) enzyme concentration. The samples exhibited maximum weight loss values of 69-73%. Meanwhile, five soil samples were collected from local sites in Lodz, Poland. A total of 31 bacterial isolates were screened and cultured on Nile blue plates. Analysis of the 16S rRNA gene sequence of the most potent producer revealed 100% similarity to . Cardboard hydrolysates whole medium, modified MSM with cardboard hydrolysate and nitrogen depleted MSM with cardboard hydrolysate were utilized for PHA production, followed by PHA productivity and cell dry weight (CDW) estimation compared to glucose as a standard carbon source. An impressive PHA accumulation of 56% CDW was attained when the waste hydrolysate was used as a carbon source. FTIR and NMR analysis of the isolated PHA indicated that functional groups of the polymer were related to PHB (polyhydroxybutyrate). Thermal analysis demonstrates that PHB and PHB-CB (PHB produced from cardboard hydrolysate) have degradation temperatures of 380 and 369 °C, respectively, which reflect the high thermal stability and heat resistance compared to the same properties for a standard polymer. This is the first demonstration of full saccharification of corrugated cardboard paper waste for high-level production of PHA. In addition, the attained PHB productivity is one of the highest levels achieved from a real lignocellulosic waste.
PubMed: 35890586
DOI: 10.3390/polym14142810