Involvement of Peptidoglycan Receptor Proteins in Mediating the Growth-Promoting Effects of Bacillus pumilus TUAT1 in Arabidopsis thaliana.

Bacillus pumilus TUAT1 acts as plant growth-promoting rhizobacteria for various plants like rice and Arabidopsis. Under stress conditions, B. pumilus TUAT1 forms spores with a thick peptidoglycan (PGN) cell wall. Previous research showed that spores were significantly more effective than vegetative cells in enhancing plant growth. In Arabidopsis, lysin motif proteins, LYM1, LYM3 and CERK1, are required for recognizing bacterial PGNs to mediate immunity. Here, we examined the involvement of PGN receptor proteins in the plant growth promotion (PGP) effects of B. pumilus TUAT1 using Arabidopsis mutants defective in PGN receptors. Root growth of wild-type (WT), cerk1-1, lym1-1 and lym1-2 mutant plants was significantly increased by TUAT1 inoculation, but this was not the case for lym3-1 and lym3-2 mutant plants. RNA-seq analysis revealed that the expression of a number of defense-related genes was upregulated in lym3 mutant plants. These results suggested that B. pumilus TUAT1 may act to reduce the defense response, which is dependent on a functional LYM3. The expression of the defense-responsive gene, WRKY29, was significantly induced by the elicitor flg-22, in both WT and lym3 mutant plants, while this induction was significantly reduced by treatment with B. pumilus TUAT1 and PGNs in WT, but not in lym3 mutant plants. These findings suggest that the PGNs of B. pumilus TUAT1 may be recognized by the LYM3 receptor protein, suppressing the defense response, which results in plant growth promotion in a trade-off between defense and growth.

Anthracene and Pyrene Biodegradation Performance of Marine Sponge Symbiont Bacteria Consortium.

Every petroleum-processing plant produces sewage sludge containing several types of polycyclic aromatic hydrocarbons (PAHs). The degradation of PAHs via physical, biological, and chemical methods is not yet efficient. Among biological methods, the use of marine sponge symbiont bacteria is considered an alternative and promising approach in the degradation of and reduction in PAHs. This study aimed to explore the potential performance of a consortium of sponge symbiont bacteria in degrading anthracene and pyrene. Three bacterial species (Bacillus pumilus strain GLB197, Pseudomonas stutzeri strain SLG510A3-8, and Acinetobacter calcoaceticus strain SLCDA 976) were mixed to form the consortium. The interaction between the bacterial consortium suspension and PAH components was measured at 5 day intervals for 25 days. The biodegradation performance of bacteria on PAH samples was determined on the basis of five biodegradation parameters. The analysis results showed a decrease in the concentration of anthracene (21.89%) and pyrene (7.71%), equivalent to a ratio of 3:1, followed by a decrease in the abundance of anthracene (60.30%) and pyrene (27.52%), equivalent to a ratio of 2:1. The level of pyrene degradation was lower than that of the anthracene due to fact that pyrene is more toxic and has a more stable molecular structure, which hinders its metabolism by bacterial cells. The products from the biodegradation of the two PAHs are alcohols, aldehydes, carboxylic acids, and a small proportion of aromatic hydrocarbon components.

Effects of novel probiotic strains of Bacillus pumilus and Bacillus subtilis on production, gut health, and immunity of broiler chickens raised under suboptimal conditions.

Probiotics are being developed as alternatives to antibiotic growth promoters. The aim of the study was to investigate the effects of 2 novel strains of Bacillus pumilus and Bacillus subtilis on production, intestinal microbiota, gut health, and immunity of broilers raised under suboptimal conditions. Day-old chicks (Cobb 500, n = 2,073) were randomly assigned into 6 groups: Con group (group fed with basal diet), Ab group (group treated with virginiamycin), groups treated with 2 levels of B. pumilus (low dose: 3 × 108 cfu/kg of feed [BPL] and high dose: 1 × 109 cfu/kg [BPH]), and groups treated with 2 levels of B. subtilis (low dose: 3 × 108 cfu/kg [BSL] and high dose: 1 × 109 cfu/kg [BSH]). Production parameters were recorded weekly. Cecal tonsils and content as well as ileum samples were collected on day 14 and day 42. Cecal tonsils were used to sort T-regulatory cells (CD4+CD8-CD25+ and CD4+CD8+CD25+) to study expression of IL-10 and interferon gamma, whereas cecal content was used for bacterial culture. Ileum samples were used to measure gene expression of tight junction proteins, mucin, and cytokines. BW and feed intake increased in the Ab, BPL, BSL, and BSH groups compared with the Con group between day 35 and day 42. The CD4+CD8-CD25+ cells expressed high levels of IL-10 in the BSH group on day 14 and in the BPL, BSL, and BSH groups on day 42 and high levels of interferon gamma in the BPL, BSL, and BSH groups on day 14 and in the BSL and BSH groups on day 42. The expression of IL-10 and interferon gamma in CD4+CD8+CD25+ cells was higher only in the BSH group on day 14 and day 42. Cecal bacterial populations of genera, Lactobacillus (day 14 and day 42) and Clostridium (day 14), were higher in the BSH group. Expression of tight junction protein increased significantly in the ileum on day 14 in the BPL (occludin, zona occludens 1 [ZO-1]), BSL (occludin, ZO-1), and BSH (occludin, ZO-1, junctional adhesion molecule 2 [JAM-2]) groups compared with that in the Con group and declined in all groups except in the BSH group (occludin, ZO-1, JAM-2) on day 42. Expression of MUC2 and IL-17F increased in all groups on day 14 and remained high on day 42 in the BSL and BSH groups. Taken together, both Bacillus probiotics altered the intestinal and immune activities, particularly on day 14, suggesting beneficial influence of probiotics.

Salt-tolerant plant growth-promoting Bacillus pumilus strain JPVS11 to enhance plant growth attributes of rice and improve soil health under salinity stress.

Rice (Oryza sativa L.) growth and productivity has been negatively affected due to high soil salinity. However, some salt-tolerant plant growth-promoting bacteria (ST-PGPB) enhance crop growth and reduce the negative impacts of salt stress through regulation of some biochemical, physiological, and molecular features. Total thirty six ST-PGPB were isolated from sodic soil of eastern Uttar Pradesh, India, and screened for salt tolerance at different salt (NaCl) concentrations up to 2000 millimolar (mM). Out of thirty-six, thirteen strains indicated better growth and plant growth properties (PGPs) in NaCl amended medium. Among thirteen, one most effective Bacillus pumilus strain JPVS11 was molecularly characterized, which showed potential PGPs, such as indole-3-acetic acid (IAA),1-aminocyclo propane-1-carboxylicacid (ACC) deaminase activity, P-solubilization, proline accumulation and exopolysaccharides (EPS) production at different concentrations of NaCl (0 -1200 mM). Pot experiment was conducted on rice (Variety CSR46) at different NaCl concentrations (0, 50, 100, 200, and 300 mM) with and without inoculation of Bacillus pumilus strain JPVS11. At elevated concentrations of NaCl, the adverse effects on chlorophyll content, carotenoids, antioxidant activity was recorded in non-inoculated (only NaCl) plants. However, inoculation of Bacillus pumilus strain JPVS11 showed positive adaption and improve growth performance of rice as compared to non-inoculated in similar conditions. A significant (P < 0.05) enhancement plant height (12.90-26.48%), root length (9.55-23.09%), chlorophyll content (10.13-27.24%), carotenoids (8.38-25.44%), plant fresh weight (12.33-25.59%), and dry weight (8.66-30.89%) were recorded from 50 to 300 mM NaCl concentration in inoculated plants as compared to non-inoculated. Moreover, the plants inoculated with Bacillus pumilus strain JPVS11showed improvement in antioxidant enzyme activities of catalase (15.14-32.91%) and superoxide dismutase (8.68-26.61%). Besides, the significant improvement in soil enzyme activities, such as alkaline phosphatase (18.37-53.51%), acid phosphatase (28.42-45.99%), urease (14.77-47.84%), and ß-glucosidase (25.21-56.12%) were recorded in inoculated pots as compared to non-inoculated. These results suggest that Bacillus pumilus strain JPVS11 is a potential ST-PGPB for promoting plant growth attributes, soil enzyme activities, microbial counts, and mitigating the deleterious effects of salinity in rice.

Mediation of induced systemic resistance by the plant growth-promoting rhizobacteria Bacillus pumilus S2-3-2.

Plant-rhizobacteria interaction and co-evolution developed adaptive strategies which may help the plant survive in nature. Plant rhizosphere soil isolates were analyzed to investigated the effects of rhizobacteria for promoting plant growth and suppress plant disease. Bacterial strains which isolated from plant rhizosphere soil were screened for elicitation of induced systemic resistance (ISR) on tobacco. Strain S2-3-2 results in significant reduction of disease severity on tobacco, it was identified as Bacillus pumilus by multilocus sequence analysis (MLSA). Strain S2-3-2 was deeper studied for pepper plant growth promotion and biological control activity against pepper bacterial spot disease. It was found that the pepper disease severity was decreased when the roots were drenched with strain S2-3-2, and the pepper plants had a higher weight and chlorophyll content, as compared with the mock-treated plants. Transcriptional expression of pathogenesis-related (PR) protein genes in pepper was analyzed by real-time PCR, gene expressions of CaPR1, CaPR4, and CaPR10 were increased when the plants were treated with strain S2-3-2. Moreover, strain S2-3-2 was tested for the production of indole-3-acetic acid (IAA), and it was determined to emit volatiles that enhance the growth of the tobacco plants. Interesting, heat-killed S2-3-2 enhance the pepper root growth, increase the gene expressions of CaPR4 and CaPR10 after pathogen challenge for 6 h, but limited to suppress the pepper bacterial spot disease as compare to the mock-treated plants. Strain S2-3-2 can be a potential biological control agent on the plant root for plant growth promoting and disease suppression.

Bacillus pumilus LZP02 Promotes Rice Root Growth by Improving Carbohydrate Metabolism and Phenylpropanoid Biosynthesis.

Elucidation of the underlying mechanisms of plant growth promotion of rhizobacteria is very important. This study explored the mechanism by which Bacillus pumilus LZP02 promotes growth in rice roots through proteomic, transcriptomic, and metabolomic techniques. The results showed that B. pumilus LZP02 promoted the absorption of phosphorous, calcium, and magnesium ions by colonization of rice roots and enhanced peroxidase, catalase, superoxide dismutase, and Ca2+Mg2+ adenosine triphosphatase activities and chlorophyll contents in rice. The proteomic results showed that most of the differentially expressed proteins were involved in carbohydrate metabolism and that the biosynthesis of other secondary metabolites was also increased. According to RNA-seq and reverse transcription-quantitative PCR analyses, expression of some genes involved in carbohydrate metabolism and phenylpropanoid biosynthesis was upregulated in rice roots. Regarding metabolomics, phenylpropanoid biosynthesis, starch and sucrose metabolism, the pentose phosphate pathway, and glyoxylate and dicarboxylate metabolism were increased. The results indicated that B. pumilus LZP02 promoted the growth of rice roots by enhancing carbohydrate metabolism and phenylpropanoid biosynthesis.

Effects of Different Culture Conditions on the Biofilm Formation of Bacillus pumilus HR10.

Many studies have focused on the significant role of biofilm formation by Bacillus in the biocontrol process. Bacillus pumilus HR10 is a plant growth-promoting rhizobacterium with multiple biocontrol functions, including promoting growth, controlling pathogens, and assisting in the formation of mycorrhizae. Currently, there is no relevant report on the biofilm formation of B. pumilus HR10 and its influencing factors. B. pumilus HR10 was found to easily form a stable biofilm structure on the surface of media, with awesome swarming ability. The optimum temperature for biofilm formation was 37 °C. B. pumilus HR10 formed most obviously at pH 7.0 and was not extremely sensitive to acidic or alkaline conditions. Most of the polysaccharide components of plant root exudates promoted the biofilm formation by B. pumilus HR10, with glucose having the greatest promoting effect. Low concentrations of Fe2+, Mg2+, Ca2+, K+, and Na+ enhanced biofilm formation. In summary, biofilm formation can improve the tolerance of B. pumilus HR10 to salt and certain heavy metal ion stresses and contribute to its application in different plants and soils with high salinity or heavy metals in the field.

Combined effects of rhizo-competitive rhizosphere and non-rhizosphere Bacillus in plant growth promotion and yield improvement of Eleusine coracana (Ragi).

This study emphasizes the beneficial role of rhizo-competitive Bacillus spp. isolated from rhizospheric and non-rhizospheric soil in plant growth promotion and yield improvement via nitrogen fixation and biocontrol of Sclerotium rolfsii causing foot rot disease in Eleusine coracana (Ragi). The selection of potent rhizobacteria was based on plant-growth-promoting attributes using Venn set diagram and Bonitur scale. Bacillus pumilus MSTA8 and Bacillus amyloliquefaciens MSTD26 were selected because they were effective in root colonization, rhizosphere competence, and biofilm formation using root exudates of E. coracana L. rich with carbohydrates, proteins, and amino acids. The relative chemotaxis index of the isolates expressed the invasive behavior of the rhizosphere. During pot and field trials, the consortium of the rhizobacteria in a vermiculite carrier increased the grain yield by 37.87%, with a significant harvest index of 16.45. Soil analysis after the field trial revealed soil reclamation potentials to manage soil nutrition and fertility. Both indexes ensured crop protection and production in eco-safe ways and herald commercialization of Bacillus bio-inoculant for improvement in crop production and disease management of E. coracana.

Analyses of the Complete Genome Sequence of the Strain Bacillus pumilus ZB201701 Isolated from Rhizosphere Soil of Maize under Drought and Salt Stress.

Bacillus pumilus ZB201701 is a rhizobacterium with the potential to promote plant growth and tolerance to drought and salinity stress. We herein present the complete genome sequence of the Gram-positive bacterium B. pumilus ZB201701, which consists of a linear chromosome with 3,640,542 base pairs, 3,608 protein-coding sequences, 24 ribosomal RNAs, and 80 transfer RNAs. Genome analyses using bioinformatics revealed some of the putative gene clusters involved in defense mechanisms. In addition, activity analyses of the strain under salt and simulated drought stress suggested its potential tolerance to abiotic stress. Plant growth-promoting bacteria-based experiments indicated that the strain promotes the salt tolerance of maize. The complete genome of B. pumilus ZB201701 provides valuable insights into rhizobacteria-mediated salt and drought tolerance and rhizobacteria-based solutions for abiotic stress in agriculture.

Antibacterial and Antispore Activities of Isolated Compounds from Piper cubeba L.

Piper cubeba L. is the berry of a shrub that is indigenous to Java, Southern Borneo, Sumatra, and other islands in the Indian Ocean. The plant is usually used in folk traditional medicine and is an important ingredient in cooking. The purpose of this study was to isolate and purify the bioactive compounds from P. cubeba L. fractions. In addition, the isolated compounds were tested for their antibacterial and antispore activities against vegetative cells and spores of Bacillus cereus ATCC33019, B. subtilis ATCC6633, B. pumilus ATCC14884, and B. megaterium ATCC14581. The phytochemical investigation of the DCM fraction yielded two known compounds: ß-asarone (1), and asaronaldehyde (2) were successfully isolated and identified from the methanol extract and its fractions of P. cubeba L. Results showed that exposing the vegetative cells of Bacillus sp. to isolated compounds resulted in an inhibition zone with a large diameter ranging between 7.21 to 9.61 mm. The range of the minimum inhibitory concentration (MIC) was between 63.0 to 125.0 µg/mL and had minimum bactericidal concentration (MBC) at 250.0 to 500.0 µg/mL against Bacillus sp. Isolated compounds at a concentration of 0.05% inactivated more than 3-Log10 (90.99%) of the spores of Bacillus sp. after an incubation period of four hours, and all the spores were killed at a concentration of 0.1%. The structures were recognizably elucidated based on 1D and 2D-NMR analyses (1H, 13C, COSY, HSQC, and HMBC) and mass spectrometry data. Compounds 1, and 2 were isolated for the first time from this plant. In conclusion, the two compounds show a promising potential of antibacterial and sporicidal activities against Bacillus sp. and thus can be developed as an anti-Bacillus agent.

A Marine Isolate of Bacillus pumilus Secretes a Pumilacidin Active against Staphylococcus aureus.

Producing antimicrobials is a common adaptive behavior shared by many microorganisms, including marine bacteria. We report that SF214, a marine-isolated strain of Bacillus pumilus, produces at least two different molecules with antibacterial activity: a molecule smaller than 3 kDa active against Staphylococcus aureus and a molecule larger than 10 kDa active against Listeria monocytogenes. We focused our attention on the anti-Staphylococcus molecule and found that it was active at a wide range of pH conditions and that its secretion was dependent on the growth phase, medium, and temperature. A mass spectrometry analysis of the size-fractionated supernatant of SF214 identified the small anti-Staphylococcus molecule as a pumilacidin, a nonribosomally synthesized biosurfactant composed of a mixture of cyclic heptapeptides linked to fatty acids of variable length. The analysis of the SF214 genome revealed the presence of a gene cluster similar to the srfA-sfp locus encoding the multimodular, nonribosomal peptide synthases found in other surfactant-producing bacilli. However, the srfA-sfp cluster of SF214 differed from that present in other surfactant-producing strains of B. pumilus by the presence of an insertion element previously found only in strains of B. safensis.

Different inflammatory responses of bovine oviductal epithelial cells in vitro to bacterial species with distinct pathogenicity characteristics and passage number.

The bovine oviduct provides the site for fertilization and early embryonic development. Modifications to this physiological environment, for instance the presence of pathogenic bacterial species, could diminish reproductive success at early stages of pregnancy. The aim of this study was to elucidate the inflammatory responses of bovine oviductal epithelial cells (BOEC) to a pathogenic bacterial species (Trueperella pyogenes) and a potentially pathogenic bacterium (Bacillus pumilus). BOEC from four healthy animals were isolated, cultured in passage 0 (P0) and passaged until P3. Trypan blue staining determined BOEC viability during 24 h co-culture with different multiplicities of infection (MOI) of T. pyogenes (MOI 0.01, 0.05, 0.1 and 1) or B. pumilus (MOI 1 and 10). BOEC remained viable when co-cultured with T. pyogenes at MOI 0.01 and with B. pumilus at MOI 1 and 10. Extracted total RNA from control and bacteria co-cultured samples was subjected to reverse transcription-quantitative polymerase chain reaction (RTq-PCR) to determine mRNA expression of various studied genes. The rate of release of interleukin 8 (IL8) and prostaglandin E2 (PGE2) from BOEC was measured by ELISA after 24 h co-culture with bacteria. RT-qPCR of various selected pro-inflammatory factors revealed similar mRNA expression of pro-inflammatory factors in BOEC co-cultured with T. pyogenes and in the controls. Higher mRNA expression of IL 1A, -1B, tumor necrosis factor alpha and CXC ligand (CXCL) 1/2, -3, -5 and IL8 and PG synthesis enzymes in BOEC co-cultured with B. pumilus was observed. In the presence of B. pumilus a higher amount of IL8 and PGE2 was released from BOEC than from controls. The viability and pro-inflammatory response of P3 BOEC incubated with bacteria was lower than in P0 BOEC. These findings illustrate the pathogenicity of T. pyogenes towards BOEC in detail and the potential role of B. pumilus in generating inflammation in oviductal cells. Culturing conditions influenced the pro-inflammatory responses of BOEC towards bacteria. Therefore, researchers conducting epithelial-bacterial in vitro co-culture should not underestimate the effects of these parameters.

Variation of preserving organic matter bound in interlayer of montmorillonite induced by microbial metabolic process.

This paper aimed to investigate the variation of preserving organic matter bound in the interlayer space of montmorillonite (Mt) induced by a microbe metabolic process. We selected Bacillus pumilus as the common soil native bacteria. The alteration of d 001 value, functional group, and C,N organic matter contents caused by bacteria were analyzed by XRD, FTIR, and elementary analyzer, respectively. XRD results showed that the d 001 value of montmorillonite increased with the concentration decreasing and decreased with the culture time increasing after interacting with bacteria indicating the interlayer space of montmorillonite was connected with the organic matter. The findings of long-term interaction by resetting culture conditions implied that the montmorillonite buffered the organic matter when the nutrition was enough and released again when the nutrition was lacking. The results of the elementary analyzer declared the content of organic matter was according to the d 001 value of montmorillonite and N organic matter which played a major impact. FTIR results confirmed that the Si-O stretching vibrations of Mt were affected by the functional group of organic matter. Our results showed that the montmorillonite under the influence of soil bacteria has a strong buffering capacity for preserving organic matter into the interlayer space in a short-term. It might provide critical implications for understanding the evolution process and the preservation of fertilization which was in the over-fertilization or less-fertilization conditions on farmland.

Differential antagonistic responses of Bacillus pumilus MSUA3 against Rhizoctonia solani and Fusarium oxysporum causing fungal diseases in Fagopyrum esculentum Moench.

Chitinase and surfactin-mediated biocontrol of Rhizoctonia solani and Fusarium oxysporum causing wilt and root rot of Fagopyrum esculentum respectively has been studied in this communication. Bacillus pumilus MSUA3 as a potential bacterial strain strongly inhibited the growth of R. solani and F. oxysporum involving the chitinolytic enzymes and an antibiotic surfactin. Plant growth promoting attributes seem to be involved in plant growth promotion and yield attributes. The action of cell-free culture supernatant (CFCS) was found deleterious to F. oxysporum and R. solani even in the heat-treated (boiled/autoclaved) CFCS. The possible involvement of surfactin in disease control was revealed by colony PCR amplification of SrfA. Chitinolytic enzyme and antibiotic surfactin evidenced differential biocontrol of F. oxysporum and R. solani by B. pumilus MSUA3. A significant reduction in disease index under gnotobiotic conditions and productivity enhancement of F. esculentum using vermiculite-based bioformulation revealed B. pumilus MSUA3 as a successful potential biocontrol agent (BCA) and an efficient plant growth promoting rhizobacterium (PGPR) for disease management and productivity enhancement of buckwheat crop.

Proteolytic system of Bacillus sp. CL18 is capable of extensive feather degradation and hydrolysis of diverse protein substrates.

1. Feathers are recalcitrant protein-rich wastes produced in huge amounts by poultry processing for meat production. Hence, feather bioconversion and protease production by Bacillus sp. CL18 were investigated. 2. Bacillus sp. CL18 demonstrated a remarkable feather-degrading potential. Through cultivations on feather broth (10 g l-1 feathers), 94.5% ± 3% of whole feathers were degraded after 4 d. Increases in soluble protein contents were observed and protease production was maximal also at d 4. This strain produced diverse proteolytic enzymes during growth. 3. Crude protease displayed optimal activity at 55°C (50-62°C), pH 8.0 (7.0-9.0) and a low thermal stability. Proteolytic activity increased in the presence of Ca2+, Mg2+, Triton X-100, Tween 20 and dimethyl sulphoxide. Inhibition profile indicated that crude protease contains, mainly, serine proteases. Enzyme preparation hydrolysed mainly casein and soy protein isolate. 4. The keratinolytic capacity of Bacillus sp. CL18 at moderate temperatures (30°C) might be appropriate for feather conversion, resulting in protein hydrolysates and proteolytic enzymes. Proteases are postulated to be added-value products that can be obtained from such a bioprocess.

Enhanced performance of the microalga Chlorella sorokiniana remotely induced by the plant growth-promoting bacteria Azospirillum brasilense and Bacillus pumilus.

Remote effects (occurring without physical contact) of two plant growth-promoting bacteria (PGPB) Azospirillum brasilense Cd and Bacilus pumilus ES4 on growth of the green microalga Chlorella sorokiniana UTEX 2714 were studied. The two PGPB remotely enhanced the growth of the microalga, up to six-fold, and its cell volume by about three-fold. In addition to phenotypic changes, both bacteria remotely induced increases in the amounts of total lipids, total carbohydrates, and chlorophyll a in the cells of the microalga, indicating an alteration of the microalga's physiology. The two bacteria produced large amounts of volatile compounds, including CO2, and the known plant growth-promoting volatile 2,3-butanediol and acetoin. Several other volatiles having biological functions in other organisms, as well as numerous volatile compounds with undefined biological roles, were detected. Together, these bacteria-derived volatiles can positively affect growth and metabolic parameters in green microalgae without physical attachment of the bacteria to the microalgae. This is a new paradigm on how PGPB promote growth of microalgae which may serve to improve performance of Chlorella spp. for biotechnological applications.

Influence of endophytic Bacillus pumilus and EDTA on the phytoextraction of Cu from soil by using Cicer arietinum.

In developing countries, soil contamination with metals is ubiquitous, which poses a serious threat to the ecosystem. The current study was designed to screen out the nested belongings of Cicer arietinum plants and Bacillus pumilus (KF 875447) in extracting copper (Cu) from contaminated soils. A pot experiment was executed by growing C. arietinum seedlings either inoculated with B. pumilus or uninoculated along with the application of 5 mM ethylenediaminetetraacetic acid (EDTA). Plants were subjected to three different concentrations of Cu (250, 350, and 500 ppm) for 48 days. An increase in Cu uptake was observed in C. arietinum plants inoculated with B. pumilus as compared to uninoculated ones. C. arietinum exhibited improved values for different growth parameters in the presence of B. pumilus, that is, root length (37%), shoot length (31%), whole plant fresh as well as (45%) dry weight (27%), and chlorophyll contents (32%). More than 70% of tolerance index (TI) was observed for plants at 500 ppm Cu treatment. Addition of B. pumilus and EDTA significantly increased metal uptake by C. arietinum up to 19 and 36%, respectively, while the application of B. pumilus and EDTA in combination increased metal accumulation by 41%. The calculated bioaccumulation and translocation factor (TF) revealed that C. arietinum possess phytoextraction potential for Cu, and this ability is significantly improved with application of B. pumilus and EDTA amendments.

Increased mRNA expression of selected antimicrobial peptides around ovulation and during inflammatory processes in the bovine endometrium postpartum.

In the uterus, the first pathogen confrontations take place at the luminal endometrial epithelium. Therefore, it is required that these cells have the potential to recognize and respond to a bacterial infection. Antimicrobial peptides (AMP), part of the innate immune system in addition to cytokines, are principal effector molecules of mucosal immunity against pathogens. One important family of AMP that can permeabilize bacterial membranes is the beta-defensin (DEFB) family, which includes the following members: DEFB1, DEFB4A, and DEFB5, lingual AMP, and tracheal AMP. The bactericidal/permeability-increasing protein is also a cationic AMP that results in the death of bacteria. Another AMP family is the S100 calcium-binding protein (S100A) family including the following members: S100A8, S100A9, S100A11, and S100A12. These AMP exert their antimicrobial action through chelation of several ions. The aim of the present study was to evaluate mRNA expression patterns of selected AMP in bovine endometrial cells collected (1) at different stages of the estrous cycle (postovulatory, early-to-mid luteal, late luteal, and pre-ovulatory phase); (2) during the puerperium depending on uterine health status (healthy, subclinical, or clinical endometritis) starting on Day 24 to 30 postpartum for 3 weeks on a weekly basis; and (3) in vitro after co-culturing with Bacillus pumilus at three different multiplicities of infection (MOI 1, 5, and 10) up to 6 hours. The results reported that the mRNA expression of all candidate AMP, except DEFB1, S100A8, and S100A9, was estrous cycle dependent. In particular, around the time of ovulation, the transcription level of most AMP was higher (P < 0.05) compared with the luteal phase. Almost all candidate AMP mRNA expression was dependent on uterine health status, with a higher transcription level (P < 0.05) in inflamed endometrial tissues, especially during the late stage of the puerperium (Day 45-51 postpartum). Members of the DEFB family were nearly unaffected in their mRNA expression in primary endometrial cells co-incubated with B. pumilus. However, S100A8 and S100A9 mRNA contents were higher after 4 and 6 hours of co-incubation with B. pumilus compared with untreated controls. In conclusion, higher mRNA expression of the candidate AMP around ovulation or in inflamed endometrial tissue during the puerperium suggests their crucial role in uterine innate immunity in the defense against invading bacteria.

Inactivation of spores by electric arcs.

BACKGROUND: In the context of spore contamination involved in bio-terrorism and food preservation, the development of new techniques for spore inactivation is an important challenge. RESULTS: Here, a successful application of electric arc discharges resulting in spore death was reported. Two types of electric arcs were compared, different with respect to their durations. The discharges with 0.5 µs duration induced a small inactivation area of 0.6 % of surface treated around their point of entry into the sample, while those with 20 µs duration induced a much larger inactivation area from 7 to 55 % of surface treated roughly proportional to the number of discharges delivered. In particular, 50 discharges of 20 µs duration induced inactivation in more than 55% of surface treated at an inactivation rate above 3.6 log10. CONCLUSIONS: These results are promising and warrant developing electric arcing as a novel method for spore inactivation.

Isolation, identification, and optimal cultivation of a marine bacterium antagonistic to Magnaporthe grisea.

In this paper, a plate confrontation method was used to isolate bacteria antagonistic to the rice blast fungus Magnaporthe grisea from samples collected from China's Dalian Bay. The antagonist strain LM-031 was obtained. We studied this strain's morphological, physiological and biochemical characteristics and analyzed its 16S rDNA sequence. We compared the effects of different culture conditions (type of media, carbon and nitrogen source, incubation temperature and time, and initial pH value) on the inhibitory effect against M. grisea. Strain LM-031 was preliminarily identified as Bacillus pumilus and was found to strongly inhibit M. grisea, especially when grown on BPY medium at an initial pH 7 for 72 h at 30°C. The optimum carbon and nitrogen sources for growth were lactose and peptone, respectively. The most suitable carbon and nitrogen sources for production of active substances were glucose and NH4Cl, respectively. Our results show that development and utilization of B. pumilus LM-031 has great potential for biological control of M. grisea.