Bacterium Paenibacillus Research Articles

Kill two birds with one stone: Biochar immobilised polydopamine coated compound bacterial agent for remediation of dibutyl phthalate contaminated soil.

The severe contamination of the plasticiser dibutyl phthalate (DBP) in agriculture soils is often accompanied by a decrease in nutrient utilisation. Though the combined application of a variety of microorganisms can simultaneously address the problems of soil contamination and nutrient deprivation, the activity and function of microorganisms can be severely inhibited by DBP, and studies on their protection under DBP contamination are almost non-existent. In this study, a compound bacterial agent KPSB was prepared by optimising with Fe3O4-modified biochar loaded with DBP-degrading bacterium Enterobacterium sp. DNB-S2 and polydopamine (PDA)-coated potassium-solubilizing bacterium Paenibacillus sp. KT. The results showed that KPSB was able to simultaneously remove DBP and increase the soil available potassium (K) content. PDA has good biocompatibility and shielding effect, and the strain KT coated by it has more complete cell membrane and stronger ability to secrete low molecular weight organic acids to promote K solubilisation. The Fe3O4-modified biochar with suitable pore structure, large specific surface area and abundant functional groups could provide a good growth microenvironment for functional microorganisms and support the growth of strains while promoting the degradation of DBP. The expression of DBP-degradation-related genes was significantly increased in KPSB, which promoted the removal of DBP. In addition, KPSB has good acid and alkali resistance and a wide range of temperature adaptability, and is able to remove DBP and increase the available K content better under different environmental conditions. These results will provide new perspectives for the research of in situ soil remediation technology.

Acetate-producing bacterium Paenibacillus odorifer hampers lung cancer growth in lower respiratory tract: an in vitro study.

Lung cancer accounts for the large majority of cancer incidence and mortality worldwide for decades. The dysbiotic microbiome and its metabolite secretions in the gut have been regarded as the dominant biological factors in oncogenesis, development, and progression, adding probiotic components of which have come to be potential therapeutic regimes. However, there still exists little knowledge about whether probiotic microorganisms in lower airways inhibit lung cancer by lung microenvironment remodulation. In this study, we performed bioinformatics analysis from previous sequencing data and specific microbiome databases to identify the potent protective microbes in lower airways, followed by bacterial cultivation and morphological verifications in vitro. We found that Paenibacillus odorifer was correlated closely with the anti-tumorous by-product acetic acid in lower respiratory tract. Additionally, the enrichment of this microorganism in the health, rather than in lung neoplasms from public data sets, further confirmed its protective activity in preserving pulmonary homeostasis. Colony cultivation of this strain and targeted metabolite analysis indicated that Paenibacillus odorifer proliferation was weakened at 37°C but lasted longer than it did at the optimal temperature. And performing as a candidate origin of acetic acid, this strain was liable to inhibit the growth of lung cancer cells in time- and dose-dependent approaches which was validated by colony formation assays. These results suggested that Paenibacillus odorifer functions as a candidate probiotic in lower airways to restrict lung cancer cell growth by releasing protective molecules, indicating a potential preventive microbial strategy.IMPORTANCEVarious types of microorganisms in lower respiratory tracts protect local homeostasis against oncogenesis. Although extensive efforts engaged in gut microbiome-mediated pulmonary carcinogenesis, emerging evidence suggested the crucial role of microbial metabolites from respiratory tracts in modulating carcinogenesis-related host inflammation and DNA damage in lung cancer, which was still not fully understood in lower respiratory tract microbes and its metabolite-mediated microecological environment homeostasis in preventing or alleviating lung cancer. In this study, we analyzed the lower respiratory tract microbiome and SCFAs expression among different lung segments from the same participants, further identifying that Paenibacillus odorifer was correlated closely with anti-tumorous by-product, acetate acid in lower respiratory tract by multi-omics analysis. And previous experiments showed this strain could inhibit the growth of lung cancer cells in vitro. These findings indicated that Paenibacillus odorifer in lower respiratory tracts might perform as a candidate probiotic against lung carcinogenesis by releasing protective factor acetate, which further presented a promising diagnostic and interventional approach in clinical settings of lung cancer.

Study of the chemical composition of the essential oil derived from Thymus lancéolatus desf, an endemic aromatic plant native from Algeria and evaluation of its efficacy against Paenibacillus larvae and Ascosphaera Apis, two diseases affecting the honeybees, Apis mellifera

The essential oil and hydrolate of Thymus lancéolatus desf, an endemic aromatic plant native to the mountains of northwestern Algeria, were tested in vitro for their antimicrobial activity against the bacteria Paenibacillus larvae, the causative agent of American foulbrood, and the fungi Ascosphaera apis, the responsible agent of chalkbrood disease in honeybees, Apis mellifera. The oil was extracted from various aerial parts of the plant using steam distillation. It shows high efficacy against both diseases, while its hydrolat demonstrates high efficacy against A.apis alone. The lethal doses (LD100) of the fungi were estimated at 0.034% and 25.30% for the essential oil and the hydrolat, respectively. The estimated concentration of the DL100 bacteria was 17.37 ul/Disc of EO. The hydrolate had no effect on P. larvae. This exceptional double efficacy of T.lancéolatus desf EO has been attributed to its particular active compound, Durenol, which constitutes 34.8% of the oil and the high quantities of its precursors (γ-Terpinene (16.71%) and Sylvestrene (15.17%) contribute to its effectiveness. Also, the abcence of acetate compound further enhances its efficacy. EO of Thyme was proven to be the most effective essential oil in vitro against P. larvae and A. apis, making it an excellent natural alternative to antibiotics.

Synergistic effects of Paenibacillus mucilaginosus and Penicillium pimiteouiense on the extraction of humic substances from lignite

Based on the common step of alkaline extraction-acid precipitation, lignite treatment techniques have been developed to improve extraction efficiency and yield of humic acid (HA). This study explored the combination of bacterium Paenibacillus mucilaginosus (P.m) LT1906 and fungus Penicillium pimiteouiense (P.p) LL2205 strains for pre- and post-treatment of lignite collected from eastern Inner Mongol to enhance HA and fulvic acid (FA) yield and plant growth-promoting activity. The lignite was subjected to P.m followed by HNO3 treatment, HNO3 followed by P.p treatment, and a combination of P.m, HNO3 and P.p treatments, then performed by alkaline extraction-acid precipitation technique. The results indicated that P.m pretreatment increased HA yield by 12.47 %, while P.p posttreatment significantly enhanced FA yield by 13.37 %. Combined bacterial and fungal treatments notably improved the total yields of HA and FA by 19.12 %. Structural analysis showed that P.m pretreatment caused the deformation on the lignite surface and the complete lignite oxidation and leaching reactions, thereby increasing the production of HA, yet had no impact on the elemental composition or chemical structure of HA. P.p posttreatment introduced oxygencontaining functional groups and reduced aromatic components through oxidative depolymerization of lignite, leading to increased FA production and HA seed germination-promoting activity.

Direct Conversion of Minimally Pretreated Corncob by Enzyme-Intensified Microbial Consortia

The presence of diverse carbohydrate-active enzymes (CAZymes) is crucial for the direct bioconversion of lignocellulose. In this study, various anaerobic microbial consortia were employed for the degradation of 10 g/L of minimally pretreated corncob. The involvement of lactic acid bacteria (LAB) and a CAZyme-rich bacterium (Bacteroides cellulosilyticus or Paenibacillus lautus) significantly enhanced the lactic acid production by Ruminiclostridium cellulolyticum from 0.74 to 2.67 g/L (p < 0.01), with a polysaccharide conversion of 67.6%. The supplement of a commercial cellulase cocktail, CTec 2, into the microbial consortia continuously promoted the lactic acid production to up to 3.35 g/L, with a polysaccharide conversion of 80.6%. Enzymatic assays, scanning electron microscopy, and Fourier transform infrared spectroscopy revealed the substantial functions of these CAZyme-rich consortia in partially increasing enzyme activities, altering the surface structure of biomass, and facilitating substrate decomposition. These results suggested that CAZyme-intensified consortia could significantly improve the levels of bioconversion of lignocellulose. Our work might shed new light on the construction of intensified microbial consortia for direct conversion of lignocellulose.

Exploring bee venom and silver nanoparticles for controlling foulbrood pathogen and enhancing lifespan of honeybees

The beekeeping industry plays a crucial role in local economies, contributing significantly to their growth. However, bee colonies often face the threat of American foulbrood (AFB), a dangerous disease caused by the Gram-positive bacterium Paenibacillus larvae (P. l.). While the antibiotic Tylosin has been suggested as a treatment, its bacterial resistance necessitates the search for more effective alternatives. This investigation focused on evaluating the potential of bee venom (BV) and silver nanoparticles (Ag NPs) as antibacterial agents against AFB. In vitro treatments were conducted using isolated AFB bacterial samples, with various concentrations of BV and Ag NPs (average size: 25nm) applied individually and in combination. The treatments were administered under both light and dark conditions. The viability of the treatments was assessed by monitoring the lifespans of treated bees and evaluating the treatment's efficiency within bee populations. Promising results were obtained with the use of Ag NPs, which effectively inhibited the progression of AFB. Moreover, the combination of BV and Ag NPs, known as bee venom/silver nanocomposites (BV/Ag NCs), significantly extended the natural lifespan of bees from 27 to 40 days. Notably, oral administration of BV in varying concentrations (1.53, 3.12, and 6.25 mg/mL) through sugary syrup doubled the bees' lifespan compared to the control group. The study established a significant correlation between the concentration of each treatment and the extent of bacterial inhibition. BV/Ag NCs demonstrated 1.4 times greater bactericidal efficiency under photo-stimulation with visible light compared to darkness, suggesting that light exposure enhances the effectiveness of BV/Ag NCs. The combination of BV and Ag NPs demonstrated enhanced antibacterial efficacy and prolonged honeybee lifespan. These results offer insights that can contribute to the development of safer and more efficient antibacterial agents for maintaining honeybee health.

Core proteome mediated subtractive approach for the identification of potential therapeutic drug target against the honeybee pathogen Paenibacillus larvae.

American foulbrood (AFB), caused by the highly virulent, spore-forming bacterium Paenibacillus larvae, poses a significant threat to honey bee brood. The widespread use of antibiotics not only fails to effectively combat the disease but also raises concerns regarding honey safety. The current computational study was attempted to identify a novel therapeutic drug target against P. larvae, a causative agent of American foulbrood disease in honey bee. We investigated effective novel drug targets through a comprehensive in silico pan-proteome and hierarchal subtractive sequence analysis. In total, 14 strains of P.larvae genomes were used to identify core genes. Subsequently, the core proteome was systematically narrowed down to a single protein predicted as the potential drug target. Alphafold software was then employed to predict the 3D structure of the potential drug target. Structural docking was carried out between a library of phytochemicals derived from traditional Chinese flora (n>36,000) and the potential receptor using Autodock tool 1.5.6. Finally, molecular dynamics (MD) simulation study was conducted using GROMACS to assess the stability of the best-docked ligand. Proteome mining led to the identification of Ketoacyl-ACP synthase III as a highly promising therapeutic target, making it a prime candidate for inhibitor screening. The subsequent virtual screening and MD simulation analyses further affirmed the selection of ZINC95910054 as a potent inhibitor, with the lowest binding energy. This finding presents significant promise in the battle against P. larvae. Computer aided drug design provides a novel approach for managing American foulbrood in honey bee populations, potentially mitigating its detrimental effects on both bee colonies and the honey industry.

The microplastics distribution characteristics and their impact on soil physicochemical properties and bacterial communities in food legumes farmland in northern China

Microplastics (MPs) pose a threat to farmland soil quality and crop safety. MPs exist widely in food legumes farmland soil due to the extensive use of agricultural film and organic fertilizer, but their distribution characteristics and their impact on soil environment have not been reported. The abundance and characteristics of MPs, soil physical and chemical properties, and bacterial community composition were investigated in 76 soil samples from five provinces in northern China. The results showed that the abundance of MPs ranged from 1600 to 36,200 items/kg. MPs in soil were mostly fibrous, less than 0.2 mm, and white. Rayon, polyester and polyethylene were the main types of MPs. The influences of MPs on soil physicochemical properties and bacterial communities mainly depended on the type of MPs. Notably, polyethylene significantly decreased the proportion of silt particles, and increased the nitrate nitrogen content as well as the abundance of MPs-degrading bacteria Paenibacillus (p < 0.05). Moreover, bacteria were more sensitive to polyesters in soil with low concentration of organic matter. This study indicated that MPs in food legumes farmland soil presented a higher-level. And, they partially altered soil physicochemical properties, and soil bacteria especially in soil with low organic matter.

Effects of Disinfectants on Bacterium Paenibacillus larvae in Laboratory Conditions.

American foulbrood is an infectious disease of the honeybee brood that causes multiple types of damage to beekeeping. The causative agent of the disease is the bacterium Paenibacillus larvae, which forms resistant infective spores and is viable for decades. After the eradication measures have been implemented, in cases of clinically visible disease, it is necessary to conduct effective final disinfections of equipment and tools. This study aimed to determine the effect of ten commercially available and commonly used disinfectants on certified strains of P. larvae under laboratory conditions, as well as to compare the obtained results among individual genotypes of P. larvae. Selected products were tested by determining the zone of inhibition using an agar diffusion test, a suspension test for viable bacteria, a surface disinfectant test, and a sporicidal effect in the suspension test. Incidin OxyFoam S and Sekusept Aktiv are both effective against all examined genotypes of P. larvae. Despadac and Despadac Secure have a bactericidal effect, but their sporocidal effect is not as satisfactory as that of Genox. Genoll does not exhibit a sporicidal effect, and Ecocide S at 1%, Bee protect H forte, and Bee protect F did not exhibit a satisfactory sporocidal effect. Additionally, EM® PROBIOTIC FOR BEES did not exhibit any bactericidal effect. The effective application of control measures and proper application of final disinfection can reduce the reoccurrence of visible clinical signs of disease, whereas methods of early diagnosis can significantly reduce the incidence of the disease.

Development of chitosan/carrageenan macrobeads for encapsulation of Paenibacillus polymyxa and its biocontrol efficiency against clubroot disease in Brassica crops

Clubroot, caused by the obligate parasite Plasmodiophora brassicae, is one of the most important diseases of brassicas. The antagonistic bacterium Paenibacillus polymyxa ZF129 can suppress clubroot while its effectiveness is often unstable. To control clubroot more effectively, the macrobeads for controlled release of ZF129 were prepared using microencapsulation technology. Macrobeads with various ratios of chitosan (2 % w/w): carrageenan (0.3 % w/v) were prepared by an ionotropic gelation method and the bacteria ZF129 was loaded into macrobeads. The 1:1 chitosan: carrageenan showed the maximum swelling ratio (634 %), and the maximum survival rate (61.52 ± 1.12 %) after freeze-drying. Fourier transform infrared revealed the electrostatic interactions between chitosan and carrageenan. The macrobeads can efficiently release ZF129 strains into phosphate buffer solution and reach equilibrium in 48 h. The maximum number of bacteria cells to be released in the soil was observed after 25–30 days. The control efficacy of ZF129 macrobeads (chitosan: carrageenan, 1:1) and ZF129 culture against clubroot disease was 76.33 ± 3.65 % and 59.76 ± 4.43 % in greenhouse experiments, respectively and the control efficacy was calculated as 60.74 ± 5.00 % for ZF129 macrobeads and 40.94 ± 4.05 % for ZF129 culture under field experiments, respectively. The ZF129 macrobeads had significant growth-promoting effects on pak choi and Chinese cabbage. The encapsulation method described in this study is a prudent approach toward efficient biopesticides utilization with reduced environmental implications.

A new β-galactosidase from Paenibacillus wynnii with potential for industrial applications

Commercial β-galactosidases exhibit undesirable kinetic properties regarding substrate affinity (Michaelis-Menten constant [KM] for lactose) and product inhibition (inhibitor constant [Ki] for galactose). An in silico screening of gene sequences was done and identified a putative β-galactosidase (Paenibacillus wynnii β-galactosidase, BgaPw) from the psychrophilic bacterium Paenibacillus wynnii. The cultivation of the wild-type P. wynnii strain resulted in very low β-galactosidase activities of a maximum of 150 nkat per liter of medium with o-nitrophenyl-β-d-galactopyranoside (oNPGal) as substrate. The recombinant production of BgaPw in Escherichia coli BL21(DE3) increased the yield ∼9,000-fold. Here, a volumetric activity of 1,350.18 ± 11.82 μkatoNPGal/Lculture was achieved in a bioreactor cultivation. The partly purified BgaPw showed a pH optimum at 7.0, a temperature maximum at 40°C, and an excellent stability at 8°C with a half-life of 77 d. Kinetic studies with BgaPw were done in milk or in milk-imitating synthetic buffer (Novo buffer), respectively. Remarkably, the KM value of BgaPw with lactose was as low as 0.63 ± 0.045 mM in milk. It was found that the resulting products of lactose hydrolysis, namely galactose and glucose, did not inhibit the β-galactosidase activity of BgaPw, but instead showed a striking activating effect in both cases (up to 144%). In a comparison study in milk, lactose was completely hydrolyzed by BgaPw in 72 h at 8°C, whereas 2 other known β-galactosidases were less powerful and converted only about 90% of lactose in the same time. Finally, the formation of galactooligosaccharides (GOS) was demonstrated with the new BgaPw, starting with pharma-lactose (400 g/L). A GOS production of about 144 g/L was achieved after 24 h (36.0% yield).

Medium Optimization and Fermentation Kinetics for Antifungal Compounds Production by an Endophytic Paenibacillus polymyxa DS-R5 Isolated from Salvia miltiorrhiza.

An endophytic bacterium Paenibacillus polymyxa DS-R5 which can effectively inhibit the growth of pathogenic fungi was isolated from Salvia miltiorrhiza in our previous study. By using hydrochloric acid precipitation, methanol extraction, silica gel column isolation, dextran gel chromatography column, and HPLC, 3 compounds with antifungal activity were isolated. To further improve the production of antifungal compounds produced by this strain, fermentation medium was optimized using one-factor-at-a-time, Plackett-Burman design, and Box-Behnken design experiments. Through statistical optimization, the optimal medium composition was determined to be as follows: 14.7g/l sucrose, 20.0g/l soluble starch, 7.0g/l corn steep liquor, 10.0g/l(NH4)2SO4, and 0.7g/lKH2PO4. In this optimized medium, the highest titer of antifungal compounds reached 3452 U/ml, which was 123% higher than that in the initial medium. In addition, in order to guide scale-up for production, logistic and Luedeking-Piret equations were proposed to predict the cell growth and antifungal compounds production. The fermentation kinetics and empirical equations of the coefficients (X0, Xm, μm, α, and β) for the two models were reported, which will aid the design and optimization of industrial processes. The degrees of fit between calculated values of the model and the experimental data were 0.989 and 0.973, respectively. The results show that the cell growth and product synthesis models established in this study may better reflect the dynamic process of antifungal compounds production and provide a theoretical basis for further optimization and on-line monitoring of the fermentation process.

Characterization of the extracellular domain of sensor histidine kinase NagS from Paenibacillus sp. str. FPU-7: nagS interacts with oligosaccharide binding protein NagB1 in complexes with N, N'-diacetylchitobiose.

We have previously isolated the Gram-positive chitin-degrading bacterium Paenibacillus sp. str. FPU-7. This bacterium traps chitin disaccharide (GlcNAc)2 on its cell surface using two homologous solute-binding proteins, NagB1 and NagB2. Bacteria use histidine kinase (HK) of the two-component regulatory system as an extracellular environment sensor. In this study, we found that nagS, which encodes a HK, is located next to the nagB1 gene. Biochemical experiments revealed that the NagS sensor domain (NagS30-294) interacts with the NagB1-(GlcNAc)2 complex. However, proof of NagS30-294 interacting with NagB1 without (GlcNAc)2 is currently unavailable. In contrast to NagB1, no complex formation was observed between NagS30-294 and NagB2, even in the presence of (GlcNAc)2. The NagS30-294 crystal structure at 1.8Å resolution suggested that the canonical tandem-Per-Arnt-Sim fold recognizes the NagB1-(GlcNAc)2 complex. This study provides insight into the recognition of chitin oligosaccharides by bacteria.

Endophyte Inoculation Enhances Growth, Secondary Metabolites and Biological Activity of Endostemon obtusifolius Grown Under Drought Stress

There is a need to cultivate medicinal plants to meet the growing demand. Their cultivation is hampered by extreme environmental conditions such as drought that affect plant growth and its pharmacological potential. Application of stress-tolerant endophytic species may potentially attenuate these negative impacts. This study assessed the effects of individual and co-inoculation of two native endophytic species (bacterium Paenibacillus polymyxa and fungus Fusarium oxysporum) on growth, physiological responses, metabolite accumulation and therapeutic efficacy of Endostemon obtusifolius subjected to varying watering regimes (well watered, mild and severe stress) under greenhouse conditions. Drought stress negatively affected root and shoot biomass, carotenoid content, chlorophyll fluorescence and relative water content in E. obtusifolius. Electrolyte leakage and malondialdehyde and hydrogen peroxide accumulation increased with drought stress. Individual and co-inoculation endophyte treatments significantly improved growth and stress tolerance mechanisms via increased osmolyte production (soluble sugars, proline), up-regulation of the enzymatic antioxidant system (superoxide dismutase) and increased antioxidant metabolite content (total phenolics, flavonoids). Antioxidant (DPPH, FRAP) and in vitro α-glucosidase activity of ethyl acetate leaf extracts were negatively affected by water stress but significantly improved when plantlets were subjected to endophyte inoculation. The most active extracts were from plants subjected to mild water stress with co-inoculation. Thus severe drought stress negatively affected growth and therapeutic efficacy of E. obtusifolius. Inoculation with beneficial endophytes enhanced the biochemical responses, osmoregulatory network and improved the therapeutic efficacy of E. obtusifolius.

Oxytetracycline-resistant Paenibacillus larvae identified in commercial beekeeping operations in Saskatchewan using pooled honey sampling.

American foulbrood (AFB) is an infectious disease of honey bee brood caused by the endospore-forming bacterium Paenibacillus larvae. P. larvae spores are resilient in the environment, thus colonies with clinical signs of AFB are often destroyed by burning to eradicate the causative agent. To prevent outbreaks of AFB, oxytetracycline metaphylaxis is widely used in North America, resulting in sustained selective pressure for oxytetracycline resistance in P. larvae. To determine if antimicrobial resistance (AMR) is present among P. larvae isolates from commercial beekeeping operations in Saskatchewan, Canada, we performed antimicrobial susceptibility testing of 718 P. larvae samples cultured from pooled, extracted honey collected from 52 beekeepers over a 2-y period, 2019 and 2020. We found that 65 of 718 (9%) P. larvae samples collected from 8 beekeepers were resistant to oxytetracycline with minimum inhibitory concentration (MIC) values of 64-256 µg/mL. Eight of 718 (1%) samples from 4 beekeepers had intermediate resistance to oxytetracycline (MIC: 4-8 µg/mL). Susceptibility testing for tylosin and lincomycin indicated that P. larvae in Saskatchewan continue to be susceptible to these antimicrobials (tylosin MIC: <1 µg/mL, lincomycin MIC: ≤2 µg/mL). Most oxytetracycline-resistant P. larvae samples were identified in northeastern Saskatchewan. Whole-genome sequence analysis identified the P. larvae-specific plasmid pMA67 with tetracycline-resistance gene tet(L) in 9 of 11 oxytetracycline-resistant P. larvae isolates sequenced. Our results highlight the advantage of using pooled, extracted honey as a surveillance tool for monitoring AMR in P. larvae.

Paenibacillus larvae and their phages; a community science approach to discovery and initial testing of prophylactic phage cocktails against American Foulbrood in New Zealand.

Background: American foulbrood (AFB) is a devastating disease of the European honey bee (Apis mellifera) and is found throughout the world. AFB is caused by the bacterium Paenibacillus larvae (P. larvae). Treatment with antibiotics is strictly forbidden in many regions, including New Zealand. Safe and natural prophylactic solutions to protect honey bees from AFB are needed. Bacteriophages are a well-studied alternative to antibiotics and have been shown to be effective against P. larvae in other countries. Methods: We employed a community science approach to obtaining samples from around New Zealand to discover novel bacteriophages. Standard isolation approaches were employed for both bacteria and bacteriophages. Host range testing was performed by agar overlay spot tests, and cocktail formulation and in vitro testing were performed in 96-well plate assays, followed by sub-sampling and CFU visualization on agar plates. Results: Herein, we describe the discovery and isolation of eight P. larvae bacterial isolates and 26 P. larvae bacteriophages that are novel and native to New Zealand. The phage genomes were sequenced and annotated, and their genomes were compared to extant sequenced P. larvae phage genomes. We test the host ranges of the bacteriophages and formulate cocktails to undertake in vitro testing on a set of representative bacterial strains. These results form the basis of a promising solution for protecting honey bees in New Zealand from AFB.

Characterization and in-depth genome analysis of a halotolerant probiotic bacterium Paenibacillus sp. S-12, a multifarious bacterium isolated from Rauvolfia serpentina

BackgroundMembers of Paenibacillus genus from diverse habitats have attracted great attention due to their multifarious properties. Considering that members of this genus are mostly free-living in soil, we characterized the genome of a halotolerant environmental isolate belonging to the genus Paenibacillus. The genome mining unravelled the presence of CAZymes, probiotic, and stress-protected genes that suggested strain S-12 for industrial and agricultural purposes.ResultsMolecular identification by 16 S rRNA gene sequencing showed its closest match to other Paenibacillus species. The complete genome size of S-12 was 5.69 Mb, with a GC-content 46.5%. The genome analysis of S-12 unravelled the presence of an open reading frame (ORF) encoding the functions related to environmental stress tolerance, adhesion processes, multidrug efflux systems, and heavy metal resistance. Genome annotation identified the various genes for chemotaxis, flagellar motility, and biofilm production, illustrating its strong colonization ability.ConclusionThe current findings provides the in-depth investigation of a probiotic Paenibacillus bacterium that possessed various genome features that enable the bacterium to survive under diverse conditions. The strain shows the strong ability for probiotic application purposes.

Whole-Genome Sequence of Paenibacillus marchantiae Isolated from the Liverwort Marchantia polymorpha subsp. ruderalis Ecotype BoGa.

The bacterium Paenibacillus marchantiae was isolated from male plants of the liverwort Marchantia polymorpha subsp. ruderalis ecotype BoGa. Here, we report on the complete genome sequence generated from long Nanopore reads. The genome sequence comprises 6,983,959 bp with a GC content of 46.02% and 6,195 predicted protein-coding genes.

Controlling Fusarium wilt of cape gooseberry by microbial consortia.

The use of microbial consortia has become a promising alternative for the management of various diseases. In this study, 18 artificial consortia were designed, consisting of five bacteria, five fungi, and a mixture of five fungi and five bacteria; from a collection of microorganisms isolated from the rhizosphere of cape gooseberry plants grown in two soils potentially suppressive against Fusarium oxysporum. When evaluated under greenhouse conditions for their biocontrol activity on cape gooseberry plants, one consortium was selected for their high efficacy (over 90%) in the control of vascular wilt caused by F. oxysporum f. sp. physali. This was constituted by ten microorganisms, the bacteria Paenibacillus peoriae, Bacillus subtilis, Lysinibacillus sp., Bacillus simplex, and Pseudomonas chlororaphis; and the fungi Beauveria bassiana, Scopulariopsis brevicaulis, Trichoderma gamsii, Trichoderma ghanense, and Trichoderma lignicola. On the other hand, four of the consortia evaluated in the presence of the pathogen mitigated the deleterious effect produced by the pathogen on plant growth, expressing higher dry weights, both in the aerial and root parts. This work represents the first report on using these mixtures of microorganisms to control vascular wilt produced by F. oxysporum. However, further studies are needed to determine their activity in cape gooseberry fields.

Medium composition and aeration to high (R,R)-2,3-butanediol and acetoin production by Paenibacillus polymyxa in fed-batch mode.

Concerning the potential application of the optically active isomer (R,R)-2,3-butanediol, and its production by a non-pathogenic bacterium Paenibacillus polymyxa ATCC 842, the present study evaluated the use of a commercial crude yeast extract Nucel®, as an organic nitrogen and vitamin source, at different medium composition and two airflows (0.2 or 0.5 vvm). The medium formulated (M4) with crude yeast extract carried out with the airflow of 0.2 vvm (experiment R6) allowed for a reduction in the cultivation time and kept the dissolved oxygen values at low levels until the total glucose consumption. Thus, the experiment R6 led to a fermentation yield of 41% superior when compared to the standard medium (experiment R1), which was conducted at airflow of 0.5 vvm. The maximum specific growth rate at R6 (0.42h-1) was lower than R1 (0.60h-1), however, the final cell concentration was not affected. Moreover, this condition (medium formulated-M4 and low airflow-0.2 vvm) was a great alternative to produce (R,R)-2,3-BD at fed-batch mode, resulting in 30g.L-1 of the isomer at 24h of cultivation, representing the main product in the broth (77%) and with a fermentation yield of 80%. These results showed that both medium composition and oxygen supply have an important role to produce 2,3-BD by P. polymyxa.