Biocontrol activity of surfactin A purified from Bacillus NH-100 and NH-217 against rice bakanae disease

The potential of the Bacillus genus to antagonize phytopathogens is associated with the production of cyclic lipopeptides. Depending upon the type of lipopeptide, they may serve as biocontrol agents that are eco-friendly alternatives to chemical fertilizers. This study evaluates the biocontrol activity of surfactin-producing Bacillus (SPB) strains NH-100 and NH-217 and purified surfactin A from these strains against rice bakanae disease. Biologically active surfactin fractions were purified by HPLC, and surfactin A variants with chain lengths from C12 to C16 were confirmed by LCMS-ESI. In hemolytic assays, a positive correlation between surfactin A production and halo zone formation was observed. The purified surfactin A had strong antifungal activity against Fusarium oxysporum, F. moniliforme, F. solani, Trichoderma atroviride and T. reesei. Maximum fungal growth suppression (84%) was recorded at 2000 ppm against F. moniliforme. Surfactin A retained antifungal activity at different pH levels (5-9) and temperatures (20, 50 and 121 °C). Hydroponic and pot experiments were conducted to determine the biocontrol activity of SPB strains and the purified surfactin A from these strains on Super Basmati rice. Surfactin production in the rice rhizosphere was detected by LCMS-ESI at early growth stages in hydroponics experiments inoculated with SPB strains. However, the maximum yield was observed with a consortium of SPB strains (T4) and purified surfactin A (T5) treatments in the pot experiment. The outcomes of the present study revealed that surfactin A significantly reduced rice bakanae disease by up to 80%. These findings suggest that purified surfactin A could be an effective biocontrol agent against bakanae disease in rice and should be incorporated into strategies for disease management.

Bacillus spp., a bio-control agent enhances the activity of antioxidant defense enzymes in rice against Pyricularia oryzae

Plant growth promoting rhizobacteria (PGPR) are found to control the plant diseases by adopting various mechanisms. Induced systemic resistance (ISR) is an important defensive strategy manifested by plants against numerous pathogens especially infecting at aerial parts. Rhizobacteria elicit ISR by inducing different pathways in plants through production of various metabolites. In the present study, potential of Bacillus spp. KFP-5, KFP-7, KFP-17 was assessed to induce antioxidant enzymes against Pyricularia oryzae infection in rice. The antagonistic Bacillus spp. significantly induced antioxidant defense enzymes i-e superoxide dismutase (1.7–1.9-fold), peroxidase (3.5–4.1-fold), polyphenol oxidase (3.0–3.8-fold), phenylalanine ammonia-lyase (3.9–4.4-fold), in rice leaves and roots under hydroponic and soil conditions respectively. Furthermore, the antagonistic Bacillus spp significantly colonized the rice plants (2.0E+00–9.1E+08) and secreted multiple biocontrol determinants like protease (1.1–5.5 U/mg of soil or U/mL of hydroponic solution), glucanase, (1.0–1.3 U/mg of soil or U/mL of hydroponic solution), siderophores (6.5–42.8 μg/mL or mg) in the rhizosphere of different rice varieties. The results showed that treatment with Bacillus spp. enhanced the antioxidant defense activities in infected rice, thus alleviating P. oryzae induced oxidative damage and suppressing blast disease incidence.

History of childhood maltreatment is associated with comorbid depression in women with migraine

BACKGROUND

A bidirectional relationship between migraine and depression suggests a neurobiological link. Adverse experiences, particularly childhood maltreatment, may alter neurobiological systems, and predispose to a multiplicity of adult chronic disorders. Our objective is to determine, within a headache clinic population of women, if depression moderates the abuse-migraine relationship.

METHODS

At six headache specialty clinics, women with migraine were diagnosed using ICHD-II criteria, and frequency was recorded. A questionnaire regarding maltreatment history, headache characteristics, current depression, and somatic symptoms was completed.

RESULTS

A total of 949 women with migraine completed the survey: 40% had chronic headache (> or =15 headache days/month) and 72% had "very severe" headache-related disability. Major depression was recorded in 18%. Physical or sexual abuse was reported in 38%, and 12% reported both physical and sexual abuse in the past. Migraineurs with current major depression reported physical (p < 0.001) and sexual (p < 0.001) abuse in higher frequencies compared to those without depression. Women with major depression were more likely to report sexual abuse occurring before age 12 years (OR = 2.30, 95% CI: 1.14 to 4.77), and the relationship was stronger when abuse occurred both before and after age 12 years (OR = 5.08, 95% CI: 2.15 to 11.99). Women with major depression were also twice as likely to report multiple types of maltreatment (OR = 2.07, 95% CI: 1.27 to 3.35) compared to those without depression.

CONCLUSIONS

Childhood maltreatment was more common in women with migraine and concomitant major depression than in those with migraine alone. The association of childhood sexual abuse with migraine and depression is amplified if abuse also occurs at a later age.

High prevalence of somatic symptoms and depression in women with disabling chronic headache

OBJECTIVE

To better define, in women with headache, the relationship of depression and somatic symptoms to headache, characterized by diagnoses, frequency, and disability.

METHODS

At six headache specialty clinics, women with headache were classified using ICHD-II criteria, and frequency was recorded. A questionnaire addressing demographics, age at onset of headache, headache-related disability, somatic symptom, and depression severity was completed. Logistic regression was performed to measure the associations of headache frequency and headache-related disability with somatic symptom and depression severity.

RESULTS

A total of 1,032 women with headache completed the survey, 593 with episodic (96% with migraine) and 439 with chronic headache (87% with migraine). Low education and household income was more common in chronic headache sufferers and in persons with severe headache disability. Somatic symptom prevalence and severity was greater in persons with chronic headache and with severe headache-related disability. Significant correlation was observed between PHQ-9 and PHQ-15 scores (r = 0.62). Chronic headache, severe disability, and high somatic symptom severity were associated with major depressive disorder (OR = 25.1, 95% CI: 10.9 to 57.9), and this relationship was stronger in the subgroup with a diagnosis of migraine (OR = 31.8, 95% CI: 12.9 to 78.5).

CONCLUSIONS

High somatic symptom severity is prevalent in women with chronic and severely disabling headaches. Synergistic relationship to major depression exists for high somatic symptom severity, chronic headache, and disabling headache, suggesting a psychobiological underpinning of these associations.

Heavy metals interact with the microbial community and affect biogas production in anaerobic digestion: A review

Heavy metals (HMs), which accumulate in digestion substrates, such as plant residues and livestock manure, can affect biogas yields during anaerobic digestion (AD). Low concentration of Cu²⁺ (0-100 mg/L), Fe²⁺ (50-4000 mg/L), Ni²⁺ (0.8-50 mg/L), Cd²⁺ (0.1-0.3 mg/L), and Zn²⁺ (0-5 mg/kg) promote biogas production, while high concentrations inhibit AD. Trace amounts of HMs are necessary for the activity of some enzymes. For example, Cu²⁺ and Cd²⁺ serve as cofactors in the catalytic center of cellulase and stimulate enzyme activity. High contents of Cd²⁺ and Cu²⁺ inhibit enzyme activity by disrupting protein structures. Trace amounts of HMs stimulate the growth and activity of methanogens, while high levels have toxic effects on methanogens. HMs affect the hydrolysis, acidification, and other biochemical reactions of organics in AD by changing the enzyme structure and they also impact methanogen growth. A better understanding of the impact of HMs on AD can provide valuable insights for improving the digestion of poultry manure and plant residues contaminated with HMs, as well as help mitigate HMs pollution. Although several studies have been conducted in this field, few comprehensive reviews have examined the effect of many common HMs on AD. This review summarizes the effects of HMs on the biogas production efficiency of AD and also discusses the effects of HMs on the activities of enzymes and microbial communities.

Qualitative analysis of biosurfactants from Bacillus species exhibiting antifungal activity

Bacillus spp. produce a broad spectrum of lipopeptide biosurfactants, among which surfactin, iturin and fengycin are widely studied families. The goals of this study were to characterize the biosurfactant activity of Bacillus spp. and to investigate their motility and biofilm formation capabilities. In addition, we extracted lipopeptides from these bacteria to assess their antifungal activities and analyzed these products by mass spectrometry (MS). B. amyloliquefaciens FZB42, Bacillus sp. NH 217 and B. subtilis NH-100 exhibited excellent biosurfactant and surface spreading activities, whereas B. atrophaeus 176s and Paenibacillus polymyxa C1225 showed moderate activity, and B. subtilis 168 showed no activity. Strains FZB42, NH-100, NH-217, 176s and CC125 exhibited excellent biofilm formation capabilities. Lipopeptide extracts displayed good antifungal activity against various phytopathogens and their associated diseases, such as Fusarium moniliforme (rice bakanae disease), Fusarium oxysporum (root rot), Fusarium solani (root rot) and Trichoderma atroviride (ear rot and root rot). Lipopeptide extracts of these strains also showed hemolytic activity, demonstrating their strong potential to produce surfactants. LCMS-ESI analyses identified the presence of surfactin, iturin and fengycin in the extracts of Bacillus strains. Thus, the strains assayed in this study show potential as biocontrol agents against various Fusarium and Trichoderma species.

Root Associated Bacillus sp. Improves Growth, Yield and Zinc Translocation for Basmati Rice (Oryza sativa) Varieties

Plant associated rhizobacteria prevailing in different agro-ecosystems exhibit multiple traits which could be utilized in various aspect of sustainable agriculture. Two hundred thirty four isolates were obtained from the roots of basmati-385 and basmati super rice varieties growing in clay loam and saline soil at different locations of Punjab (Pakistan). Out of 234 isolates, 27 were able to solubilize zinc (Zn) from different Zn ores like zinc phosphate [Zn₃ (PO₄)₂], zinc carbonate (ZnCO₃) and zinc oxide (ZnO). The strain SH-10 with maximum Zn solubilization zone of 24 mm on Zn₃ (PO₄)₂ore and strain SH-17 with maximum Zn solubilization zone of 14–15 mm on ZnO and ZnCO₃ores were selected for further studies. These two strains solubilized phosphorous (P) and potassium (K) in vitro with a solubilization zone of 38–46 mm and 47–55 mm respectively. The strains also suppressed economically important rice pathogens Pyricularia oryzae and Fusarium moniliforme by 22–29% and produced various biocontrol determinants in vitro. The strains enhanced Zn translocation toward grains and increased yield of basmati-385 and super basmati rice varieties by 22–49% and 18–47% respectively. The Zn solubilizing strains were identified as Bacillus sp. and Bacillus cereus by 16S rRNA gene analysis.

Ochrobactrum ciceri sp. nov., isolated from nodules of Cicer arietinum

A Gram-staining-negative, aerobic, rod-shaped, non-spore-forming bacterial strain, Ca-34(T), was isolated from nodules of chickpea (Cicer arietinum) in Pakistan and studied for its taxonomic affiliation. The almost full-length 16S rRNA gene sequence showed highest similarities to those of strains of the genus Ochrobactrum. Based on results of MALDI-TOF MS and 16S rRNA gene sequence similarity (98.6 %), strain Ca-34(T) and Ochrobactrum intermedium LMG 3301(T) are phylogenetic neighbours; the two strains shared DNA-DNA relatedness of 64 %. The fatty acid profile [predominantly C(18 : 1)omega7c (67.7 %) and C(19 : 0) cyclo omega8c (19.6 %)] also supported the genus affiliation. Metabolically, strain Ca-34(T) differed from other type strains of Ochrobactrum in many reactions and from all type strains in testing positive for gelatin hydrolysis and in testing negative for assimilation of alaninamide and l-threonine. Based on phenotypic and genotypic data, we conclude that strain Ca-34(T) represents a novel species, for which we propose the name Ochrobactrum ciceri sp. nov. (type strain Ca-34(T) =DSM 22292(T) =CCUG 57879(T)).

Molecular Identification and Genetic Characterization of Macrophomina phaseolina Strains Causing Pathogenicity on Sunflower and Chickpea

Macrophomina phaseolina is the most devastating pathogen which causes charcoal rot and root rot diseases in various economically important crops. Three strains M. phaseolina 1156, M. phaseolina 1160, and M. phaseolina PCMC/F1 were tested for their virulence on sunflower (Helianthus annuus L.) and chickpea (Cicer arietinum L.). The strains showed high virulence on both hosts with a disease score of 2 on chickpea and sunflower. The strains also increased the hydrogen per oxide (H2O2) content by 1.4- to 1.6-fold in root as well as shoot of chickpea and sunflower. A significant increase in antioxidant enzymes was observed in fungal infected plants which indicated prevalence of oxidative stress during pathogen propagation. The M. phaseolina strains also produced hydrolytic enzymes such as lipase, amylase, and protease with solubilization zone of 5-43 mm, 5-45 mm, and 12-35 mm, respectively. The M. phaseolina strains were identified by 18S rRNA and analyzed for genetic diversity by using random amplified polymorphic DNA (RAPD) markers. The findings based on RAPD markers and 18S rRNA sequence analysis clearly indicate genetic variation among the strains collected from different hosts. The genetically diverse strains were found to be pathogenic to sunflower and chickpea.

Fabrication of Electrospun Probiotic Functionalized Nanocomposite Scaffolds for Infection Control and Dermal Burn Healing in a Mice Model

The importance of microbiota paves the way to use microbial cells as medicines to treat pathobiomic diseases. This study reported the fabrication of probiotic (Enterococcus mundtii QAUEM2808)-functionalized nanocomposite scaffolds of poly(vinyl alcohol)/poly(vinylpyrrolidone)/glycerol via electrospinning. Scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis resolved the living composite structure and supported the encapsulation of E. mundtii throughout the nanostructured (318 ± 12 nm) fibers of bioscaffold membranes. The shelf life evaluation of 4-week-old samples supported that bioscaffolds showed an enhancement in probiotic survival count by 2.78 ± 0.10 log₁₀ colony-forming units (cfu) versus counterpart biodispersion. The swelling and antagonistic evaluation showed that a bioscaffold is degradable in a simulated wound fluid which is essential for activation of probiotic strains to antagonize infection-causing Gram-positive and Gram-negative pathogens. A second-degree contact burn was made on the dorsum of male BALB/c mice (n = 30). The wounds were left open for 2 days to mimic burn contamination, and the mice were randomized into negative (untreated), positive (silver sulfadiazine cream), vehicle (biodispersion and nanoscaffold), and experimental bioscaffold groups (n = 6/group). These treatments were applied on 2, 6, 10, and 14 days postburn. A comparative wound closure, histopathology, and wound microbial evaluation demonstrated that the bioscaffolds accelerate epithelialization, collagen deposition, and hair follicle formation, inhibit harmful bacteria, and provide interference benefits. In particular, the probiotic active bioscaffold membrane could serve as a novel candidate to control infections and speed up the healing of burn wounds.

Electrospun Microbial-Encapsulated Composite-Based Plasticized Seed Coat for Rhizosphere Stabilization and Sustainable Production of Canola ( Brassica napus L.)

Plant-growth-promoting bacteria show promises in crop production; nevertheless, innovation in their stable delivery is required for practical use by farmers. Herein, the composite of poly(vinyl alcohol)/poly(vinylpyrrolidone) plasticized with glycerol and loaded with the microbial consortium ( Bacillus subtilis plus Seratia marcescens) was fabricated and engineered onto canola ( Brassica napus L.) seed via electrospinning. Scanning electron microscopy showed that the biocomposite is a one-dimensional membrane, which encapsulated microbes in a multilayered nanostructure, and their interfacial behavior between microorganism and seed is beneficial for safer farming. A universal testing machine and thermogravimetric analysis demonstrated that the biocomposite holds sufficient thermomechanical properties for stable handling and practical management. A spectroscopic study resolved the living hybrid-polymer structure of the biocomposite and proved the plasticizing role of glycerol. A swelling study supports the degradation of the biocomposite in the hydrophilic environment as a result of the leaching of the plasticizer, which is important for the sustained release of microbial cells. A shelf life study supported that the biocomposite seed coat placed a threshold level of microbes [5.675 ± 0.48 log₁₀ colony forming units (CFU)/seed] and maintained their satisfactory viability for 15 days at room temperature. An antifungal and nutrient-solubilizing study supported that the biocomposite seed coat could provide opportunities to biocontrol diseases and improve nutrient acquisition by the plant. A pot study documents the better performance of the biocomposite seed coat on seed germination, seedling growth, leaf area, plant dry biomass, and root system. A chemical and microbial study demonstrated that the biocomposite seed coat improved the effectiveness of the bioinoculant in the root-soil interface, where they survive, flourish, and increase the nutrient pool status. In particular, this study presents advances in the fabrication of the biocomposite for encapsulation, preservation, sustained release, and efficacious use of microorganisms onto seeds for precision farming.

Molecular characterization of the modular chitin binding protein Cbp50 from Bacillus thuringiensis serovar konkukian

Bacillus thuringiensis is an insecticidal bacterium whose chitinolytic system may be exploited to improve the insecticidal system of Bt-crops. A nucleotide fragment of 1368 bp from B. thuringiensis serovar konkukian S4, containing the complete coding sequence of the chitin binding protein Cbp50, was cloned and sequenced. Analyses have shown the protein to contain a modular structure consisting of an N-terminal CBM33 domain, two copies of a fibronectin-like domain and a C-terminal chitin binding domain classified as CBM5. The Cbp50 protein was heterologously expressed in Escherichia coli, purified and assessed for chitin binding activity. A deletion mutant (CBD-N; containing only the N-terminal CBM33 domain) of Cbp50 was produced to determine the role of C-terminal domains in the binding activity of the protein. The full-length Cbp50 was shown to bind β-chitin most efficiently followed by α-chitin, colloidal chitin and cellulose. The polysaccharide binding activity of CBD-N was drastically decreased. The data demonstrate that both the N-terminal and C-terminal domains of Cbp50 are essential for the efficient binding of chitin. The purified Cbp50 showed antifungal activity against the phytopathogenic fungus Fusarium oxysporum and the opportunistic human pathogen Aspergillus niger. This is the first report of a modular chitin binding protein in bacteria.

Dicistronic binary vector system-A versatile tool for gene expression studies in cell cultures and plants

Dicistronic binary vector constructs based on pGreenII vectors for Agrobacterium mediated gene transfer alleviate the translational expression monitoring of a target gene in plants. The functionality of the transformation vectors was proven by marker gene constructs containing a mannopine synthase promoter (p-MAS) fused to a beta-glucuronidase (gus) gene followed by an internal ribosome entry site and a firefly luciferase (luc) gene. The cap-dependent translation of a physically independent target protein can be monitored by the cap-independently co-translated luciferase, because both mRNAs are located on the same strand. Among three different IRES elements, the tobamo IRES element showed highest activity in transient expression. As a proof of principle for physiological studies the gus gene was replaced by a sodium antiporter gene (Atnhx1). Comparative studies with Atnhx1 transgenic luc expressing tobacco cell cultures and pea plants (Pisum sativum L.) showed improved salt tolerance in relation to their wild type counterparts grown under corresponding conditions. A coincidence of the luc gene expression and increased sodium chloride tolerance is demonstrated by measurement of luminescence and cell growth.

Pulsatile tinnitus in cerebrovascular arterial diseases

In a prospective study of 100 patients evaluated at the University of Wisconsin Stroke Program, we sought to document cases of incidental pulsatile tinnitus that could be ascribed to stenotic, occluded, ectatic, tortuous, or dissected craniocerebral arteries. Angiographic detail, magnetic resonance angiography, catheter-generated x-ray angiography, or both were necessary for inclusion into either Group 1 (n=29), those with pulsatile tinnitus, or Group 2 (n=71), those without pulsatile tinnitus. Patients did not appear to have head/neck tumors, aneurysms, arteriovenous malformations, transmitted cardiac murmurs, or venous etiologies for their tinnitus. Age, sex, and stroke risk factor profiles did not separate the two groups. Factors that were significantly more common in Group 1 included (1) severe, > or =70% stenosis through complete occlusion, internal carotid artery disease (59% for Group 1 v 21% for Group 2, P<.05); (2) severe, > or =50% stenosis through occlusion, vertebral or basilar disease (38% v 18%, P<.05); (3) tortuosity of at least one carotid, vertebral, or basilar artery (31% v 18%, P<.05); and (4) basilar artery dolichoectasia (14% v 0%, P=.006). We also noted when pulsatile tinnitus was either "objective" (11 of 100, 11%) or "subjective" (18 of 100, 18%), duration of tinnitus, transient versus permanent nature of tinnitus, and reasons seen in consultation by one of us.

Recurrent ischemic strokes in a patient with Medtronic-Hall prosthetic aortic valve and valve strands

Fine strands associated with prosthetic heart valves have been demonstrated with transesophageal echocardiography, but the pathologic identity of these strands is unclear. A case of a man with a prosthetic aortic Medtronic-Hall valve with prominent valve strands and recurrent strokes is discussed. The patient underwent valve replacement surgery, and histopathologic examination of the strands identified them as Lambl's excrescences.

Isolation and Structure of Neriucoumaric and Isoneriucoumaric Acids from the Leaves of Nerium oleander

Two new coumaryloxy triterpenoids, neriucoumaric and isoneriucoumaric acids, have been isolated from fresh, undried and uncrushed leaves of NERIUM OLEANDER and their structures established as 3beta-hydroxy-2alpha-cis- P-coumaryloxy-urs-12-en-28-oic acid and 3beta-hydroxy-2alpha- TRANS- P-coumaryloxy-urs-12-en-28-oic acid respectively, through chemical and spectroscopic methods.

Tortuosity of carotid and vertebral arteries: a magnetic resonance angiographic study

Nine patients (group A) were found on magnetic resonance angiography (MRA) to have excessive carotid artery, vertebral artery, and vertebrobasilar junction tortuosity. A control group (group B) were age- and sex-matched to group A patients, were selected randomly from our MRA or stroke data banks, and had not undergone MRA for evaluation of migraine, "carotidynia," or pulsatile tinnitus. Factors more prevalent in group A patients included migraine, chronic daily headache, carotidynia, pulsatile tinnitus, and a positive family history of headache. Factors more prevalent in group B patients included a positive family history of stroke, large-vessel atherosclerosis, and scan evidence of ischemic infarctions; many group B patients had undergone MRA for stroke or transient ischemic attack evaluation. Men were slightly underrepresented at 44%, and were younger than women (34 +/- 6 years vs. 43 +/- 3 years; p = 0.01). Relationships in this preliminary study between arterial tortuosity and migraine seem evident.

Isolated petrous carotid stenosis and transient ischemic attack

Although anterior circulation transient ischemic attacks (TIAs) tend to be more common in patients with extra- cranial carotid arterial disease than in those with intracranial carotid or middle cerebral arterial disease, the authors recently encountered 4 patients with both recurrent, stereotypical TIAs as well as isolated stenosis of their petrous internal carotid artery (ICA). While the gold standard for establishing the diagnosis of intracranial large-artery disease has always been conventional angiography, magnetic resonance angiography changes, confirmed with intra-arterial digital subtraction angiography in 2 of these patients, were quite sufficient to define the occlusive disease in each of the cases. Petrous ICA stenosis is not uncommon, but it has often been overshadowed by the search for extracranial ICA disease that might be amenable to surgical reconstruction.