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Fe S clusters are prosthetic groups present in all organisms. Proteins with Fe S centers are involved in most cellular processes. ISC and SUF are machineries necessary for the formation and insertion of Fe S in proteins. Recently, a phylogenetic analysis on more than 10,000 genomes of prokaryotes have uncovered two new systems, MIS and SMS, which were proposed to be ancestral to ISC and SUF. SMS is composed of SmsBC, two homologs of SufBC(D), the scaffolding complex of SUF. In this review, we will specifically focus on the current knowledge of the SUF system and on the new perspectives given by the recent discovery of its ancestor, the SMS system. • SufS and SufU sulfurtransferase for SufS sulfur transfer • SufU as zinc-containing protein • The two cofactors (Flavin and Fe-S) of SufBCD scaffold. • SmsCB is the scaffold of the ancestral system • Unknown sulfur donor for SMS system [ABSTRACT FROM AUTHOR]

[Display omitted] • Fe 3 O 4 @UiO-66-NH 2 @PEI was designed for broad-spectrum enrichment of bacteria. • Dual-mode sensing platform was constructed for sensitive and accurate detection of bacteria. • The platform achieved detection in real-sample with satisfactory results. • The sensor of Fe 3 O 4 @UiO-66-NH 2 @PEI exhibited excellent storage stability. Bacteria-induced food pollution poses a serious threat to human health. To detect early and sensitive traces of bacteria in food, a poly (ethyleneimine) (PEI)-modified magnetic organic framework material (Fe 3 O 4 @UiO-66-NH 2 @PEI) was prepared for broad-spectrum enrichment and dual-mode detection of typical gram-positive bacteria (Bacillus subtilis, B. subtilis) and gram-negative bacteria (Escherichia coli, E. coli) using Schiff's base reaction. Due to the positive charge caused by the abundance of amino groups, Fe 3 O 4 @UiO-66-NH 2 @PEI exhibited rapid enrichment of E. coli and B. subtilis within 12 min through the electrostatic interaction with bacteria. The biosensor based on Fe 3 O 4 @UiO-66-NH 2 @PEI achieved sensitive detection of E. coli and B. subtilis using the adenosine triphosphate (ATP) bioluminescence technology within the detection range of 101-107, and the detection limits were 44 and 57 CFU/mL, respectively under optimal experimental conditions. Moreover, a fluorescence platform was constructed by Fe 3 O 4 @UiO-66-NH 2 @PEI to achieve more diversified detection and reliable detection results for E. coli and B. subtilis. Within the detection range of 101-107, Fe 3 O 4 @UiO-66-NH 2 @PEI exhibited satisfactory linearity with detection limits of 6 CFU/mL and 14 CFU/mL. This biosensor using ATP bioluminescence and fluorescence technology showed remarkable recoveries (85.3–108.5 %) for E. coli and B. subtilis in biscuit matrices, indicating a bright prospect of the dual-mode platform for bacteria detection in food. [ABSTRACT FROM AUTHOR]

• Ultrasound can modulate the antioxidant activity and functionality of UAFP in vitro. • Sonication altered the composition, structure, and morphology of okara. • UAFP and UAFP4 (>1 kDa) promote cell growth and have good stability. This study investigated the effects of ultrasound-assisted fermentation (UAF) on the preparation of antioxidant peptides (UAFP) from okara and examined their content, chemical structures, and antioxidant activity. After the optimal ultrasonic processing (time, 20 min; frequency, 45 KHz; power, 120 W/L), the peptide content yield reached the maximum of 12.36 ± 0.02 mg/mL, and their DPPH free radical scavenging rate was 65.15 ± 0.32 %. UAF increased the number of globular aggregates with deeper gullies, a looser structure, and higher porosity. The experiments conducted using the oxidative stress injury model of HepG2 cells showed that okara UAFP promoted cell growth and exerted a protective effect. Moreover, ultrasonic treatment remarkably improved the environmental stability (NaCl, glucose, sodium benzoate, temperature, pH, metal ions) and antioxidant activity of UAFP. Concisely, optimal ultrasonic processing can aid the fermentation of agroindustrial by-products to prepare antioxidant peptides, such as natural food antioxidant peptides from soybean waste. [ABSTRACT FROM AUTHOR]

Impedance spectroscopy is a technique used to characterize electrochemical systems, increasing its applicability as well to monitor cell cultures. During their growth, Bacillus species have different phases which involve the production and consumption of different metabolites, culminating in the cell differentiation process that allows the generation of bacterial spores. In order to use impedance spectroscopy as a tool to monitor industrial interest Bacillus cultures, we conducted batch fermentations of Bacillus species such as B. subtilis , B. amyloliquefaciens, and B. licheniformis coupled with this technique. Each fermentation was characterized by the scanning of 50 frequencies between 0.5 and 5 MHz every 30 min. Pearson's correlation between impedance and phase angle profiles (obtained from each frequency scanned) with the kinetic profiles of each strain allowed the selection of fixed frequencies of 0.5, 1.143, and 1.878 MHz to follow-up of the fermentations of B. subtilis , B. amyloliquefaciens and B. licheniformis, respectively. Dielectric profiles of impedance, phase angle, reactance, and resistance obtained at the fixed frequency showed consistent changes with exponential, transition, and spore release phases. • The various Bacillus species were monitored by impedance spectroscopy. • Different fixed frequencies for monitoring each Bacillus species were determined. • Dielectric spectroscopy allows identify the different growth stages related to the cell differentiation process. [ABSTRACT FROM AUTHOR]

In the current study, the proteolytic enzyme (serratiopeptidase) was used to enhance the efficacy of Bacillus subtilis (B. subtilis) probiotic as a growth promotor in broiler chicken. The effects of serratiopeptidase on the efficacy of different levels of B. subtilis as a growth promotor in broiler chicks were evaluated regarding growth performance traits, villus histomorphometric characterization, and intestinal microbiota count. Day-old broiler chicks (n = 120) were allocated into 4 groups having 3 replicates/group. In the control group (C), the basal diet was kept without supplementation. In treatment groups (P100, P150, and P200), the basal diet was supplemented with 100, 150, and 200 mg probiotics, respectively besides 30 mg proteolytic enzyme in the 3 treated groups for 4 wk. The performance parameters were significantly affected by the supplementation of serratiopeptidase to the B. subtilis treatment groups. Feed intake (FI), body weight gain (WG), feed conversion ratio (FCR), and dressing percent were significantly improved in the treatment groups as compared to the control group. Significantly, the lowest feed intake was recorded for the P200 group. The highest body weight gain and dressing percentage were recorded for the P200 group. An improved FCR was recorded in the P200 group (1.7) as compared to the control group. The different levels of B. subtilis supplemented with serratiopeptidase revealed significant improvements (P <0.05) in the morphology of the intestine by showing increases in villus height and width and crypt depth of the small intestine. The microbial count revealed that E. coli and salmonella colonies were significantly reduced in the P200 group as compared to the control and other treatment groups. In conclusion, the supplementation of B. subtilis with serratiopeptidase as a growth promoter in broiler chicks significantly improved the overall performance, and intestinal health and reduced microbial load contributing to optimizing the performance of broiler chickens. The greatest improvement was observed in the P200 group fed with B. subtilis as a probiotic and serratiopeptidase enzyme (200 mg:30 mg). [ABSTRACT FROM AUTHOR]

The aim of the current study was to evaluate egg production, quality, and apparent retention (AR) of components in response to a multi-dose application of a single strain Bacillus subtilis (SSB ; DSM29784) in a corn-soybean meal basal diet fed to hens (19 to 48 wk of age). The treatments consisted of a basal diet with either no probiotic (control, CON), 1.1E+08 (low, LSSB), 2.2E+08 (medium, MSSB) or 1.1E+09 (high, HSSB) CFU/kg of diet. A total of 336, 19-wk old Shaver White layers were used at a stocking density of 7 and 6 hens/replicate-cage in layer I (week-19 to 28) and layer II (week-29 to 48) phases, respectively. Evaluated variables included feed intake (FI), body weight (BW), feed conversion ratio (FCR), egg production, weight, mass, and egg quality (shell thickness, shell breaking strength, albumen height (AH), and Haugh unit (HU)). Excreta was collected at the end of week-28 for AR of components and apparent metabolizable energy (AME). Supplementation of SSB increased (P = 0.008) FI during peak egg-lay (week-24) and BW increased linearly (P = 0.019) in early layer II (week-32). In layer I, LSSB compared with CON increased EM (g/egg) by 3.3% (P = 0.049). In layer II, SSB inclusion tended to improve FCR (linear, P = 0.094; g FI: g EM). Although shell breaking strength was lowest at week-20 with HSSB (4.518 vs. 4.889 kgf for HSSB vs. CON; P = 0.045), AH and HU were improved at higher dose of SSB, in both phases (P ≤ 0.005). Apparent retention of dry matter, AME, and minerals were improved (P < 0.0001) in a dose response. Hence, while the low dose of B. subtilis DSM29784 improved hen performance and maintained egg quality in both phases, a higher dose of SSB improved the interior protein quality of eggs (AH and HU). [ABSTRACT FROM AUTHOR]

The aim of the present study was to evaluate the efficacy of Bacillus -based probiotic in pullet to lay period. A total of 12-wk-old 384 Hy-line Brown pullets (initial BW of 1.05 kg, 8 replications; 16 birds per replication pen) were used in a 6-wk feeding trial. Birds were blocked based on BW and randomly allotted to 1 of 3 dietary treatments that consisted of basal diet as CON; GPM, basal diet+ (GalliPro Max/ B. subtilis , 500 g/ton); GPT, basal diet+ (GalliPro Tect/ B. licheniformis , 500 g/ton). During the pullet stage, birds that were fed CON diet and CON diet supplemented with either 500 g/ton B. sublitis or B. licheniformis were randomly assigned to 1 of 7 treatments with 9 replications (6 birds per replication) during lay period. For this, a total of 162 birds fed CON diets were randomly chosen and subdivided into 3 groups and fed CON, GPM, and GPT diets. From the birds that were fed either GPM or GPT diet at pullet phase, about 108 birds from each treatment were randomly chosen and were subdivided into 2 treatments and fed either GPM or GPT diet. The feed intake was higher (P < 0.05) in GPT treatment and lower (P < 0.05) in GPM treatment compared with CON during the pullet period. In addition, the excreta Escherichia coli counts were reduced (P < 0.05) in pullets fed GPT diet. The egg production rate significantly increased (P < 0.05) for layers fed GPM diet and a slight increase was also seen for GPT treatment birds compared with CON during week 32. During the lay period, the average mean values for albumen height and yolk color at week 25 to 45 were higher (P < 0.05) for GPM fed birds compared with those fed GPT and CON diets. In conclusion, Bacillus -based probiotic supplementation in the diet conferred some positive effects during pullet to lay period. [ABSTRACT FROM AUTHOR]

Abstract On the face of impending global water resources, designing cost effective and water treatment technologies and materials thereof is highly important. In the era of nanoparticles and composites various nanoparticles are introduced for water treatment. Herewith, we are reporting a new nanocomposite, Fe 3 O 4 -TSPED-Tryptophan (FTT), for the adsorption of Congo Red (CR) dye and it's antibacterial properties. The FTT nanocomposite is prepared and characterized using FT-IR, XRD, TEM, FE-SEM, VSM, BET, TGA, and UV–Vis Spectroscopy techniques. The adsorption efficacy of the dye is assessed by varying various parameters such as pH, dye concentration, adsorbent dose and time. The adsorption isotherm is found to follow Langmuir isotherm model and the rate of adsorption well fitted to pseudo-second order kinetics. We further checked the antibacterial activity of the dye against gram negative (Escherichia coli) and gram positive (Bacillus subtilis) bacterial strain. FTT nanocomposite responds positively towards antibacterial activity. All together and from future aspect, the currently sysnthesized nanocomposite might be a good adsorbent for water remediation to trap CR and inhibit the bacterial activity. Graphical abstract Unlabelled Image Highlights • Novel synthesis of amino acid modified iron oxide nanopartciles using TSPED (FTT) as a crosslinker. • The FTT nanocomposite exploited as good adsorbent for Congo Red dye. • The adsorption capacity of dye depends upon highly on pH. • Evaluation of antibacterial activity against E. coli and B. subtilis • Multiple adsorption mechanism are involved in the Congo Red dye adsorption. [ABSTRACT FROM AUTHOR]

A total of 816 1-day-old Ross 308 broiler chicks with an average initial body weight (BW) of 44.01 ± 0.62 g were used in a 6-wk feeding trial. Birds were blocked based on BW and randomly allotted to 1 of 6 dietary treatments (8 replicate pens per treatment with 17 birds per replication pen) in a 3 × 2 factorial arrangement with 3 levels of metabolizable energy (ME) and crude protein (CP) with constant amino acid (100% ME and CP, 98.8% ME and CP, and 97.6% ME and CP) supplemented with or without 500 g/ton of Bacillus -based probiotics. As a result of this study, a significant reduction (P < 0.05) in BW and an increment in feed conversion rate (FCR) were observed with the reduction in the diet density during finisher and overall experiment periods. During the growing and finishing periods, the birds fed probiotic supplemented diets were heavier (P < 0.05) than those fed diets without probiotic. The FCR was also improved (P < 0.05) in probiotic supplemented groups during these periods, but feed intake (FI) remained unaffected compared to birds without probiotic supplemented diets. The apparent total tract digestibility (ATTD) of dry matter (DM) tended (P = 0.051) to be lower in ME- and CP-reduced diets compared with control. In addition, the ATTD of nitrogen (N) and energy was significantly lower (P < 0.05) in ME and CP-reduced diets than the control diet. A trend in the reduction (P = 0.059) of NH3 gas emission from the excreta was observed for birds fed ME- and CP-reduced diets compared with control diets. In addition, birds fed probiotic supplemented diets also showed reduced (P < 0.05) NH3 emission compared to those fed diet without probiotic. In conclusion, inclusion of probiotic to ME- and CP-reduced diet improved performance, had comparable effect on meat quality, and reduced ammonia emission from the excreta. No interactive effects of diet types and probiotic were observed. [ABSTRACT FROM AUTHOR]

Abstract Shortwave ultraviolet (UVC) radiation is commonly used for sterilization of drinking water. However, its low transmittance within opaque liquids limits its use for milk and other liquid food products. The objective of this study was to assess the efficacy of UV pretreatment on thermal inactivation of B. subtilis spores in skim cow milk, whole cow milk and whole sheep milk. In this work, UV treatment was applied by using a coiled tube UV unit with a perfluoroalkoxy tube around a quartz sleeve containing a 254-nm UV lamp. It was observed that UV pretreatment (D Act 2.37 ± 0.126 J/ml) combined with thermal treatment at 110 °C for 30 s resulted in a reduction of approximately 6 log CFU/mL in bovine skim milk, 2.90 log CFU/ml in whole bovine milk and 1.1 log CFU/ml in ovine milk. The results showed that UV in combination with heat can possibly be an alternative to sterilization of skim milk at lower temperatures compared to ultra high temperature (UHT) treatment (135 °C, 3 s). Highlights • Skimmed cow milk, whole cow milk and sheep milk were irradiated using coiled tube UV reactor to inactivate spores. • UV-C in combination with heat results in higher inactivation of spores. • UV-C can reduce sterilization temperature of skim milk significantly. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Vancomycin-modified gold nanoparticles were synthesized by a one-pot reaction. • A colorimetric and test stripe-based assay was established for Gram-positive bacteria. • This assay is rapid and easy, and does not require the use of any microscopic devices. • Six species of Gram-positive and Gram-negative bacteria were tested. Abstract Bacteria are the most principal pathogens threatening human health. Rapid, simple, and sensitive identification and assay for bacteria are greatly desired for clinical diagnosis and environmental monitoring. In this work, a commonly used antibiotic vancomycin (Van) was used to synthesize gold nanoparticles (Au NPs) by a simple one-pot reaction, and the resultant Van-coated Au NPs (denoted as Van-AuNPs) can selectively interact with Gram-positive bacteria and thus be used to differentiate Gram-positive bacteria from Gram-negative ones through the change of their red color. On this basis, Van-AuNPs-based visual colorimetric assay was established for Gram-positive bacteria. The detection limits of bare eyes for Gram-positive S. aureus , M. luteus, and B. subtilis are 1 × 109, 1 × 109, and 1 × 109 cells/mL, respectively, according to the color of the spots on the test strip without the use of any microscopic devices. We also used this method to detect S. aureus in orange juice and tap water with excellent recoveries. Compared with conventional bacterial identification methods, this assay is rapid and easy, and is promising to be used as a rapid method for the identification and quantification of bacteria in clinics, environment, and fieldwork. [ABSTRACT FROM AUTHOR]

Abstract We studied mycotoxigenic fungi contaminating stored wheat grain, measured the toxins they secreted, and assessed their harmfulness. We focused on one common genus Alternaria, and chose 19 isolates representing A. compacta to study how different strains differed in their mycotoxin secretion and toxicity. Toxicity was assessed in a bioassay with a model bacteria Bacillus subtilis. All 19 A. compacta strains secreted toxins. Both the mycotoxin pattern and the fungal toxicity differed between the A. compacta stains. It seemed that some other toxins than alternariols or altenue acted as the main virulence factors of A. compacta against B. subtilis. We suggest that the most commonly studied mycotoxins do not necessarily indicate the toxicity of the fungi. The high variation in the amounts and toxins that different Alternaria species and strains secrete pose a challenge to the food supply chain. [ABSTRACT FROM AUTHOR]

Highlights • An alternative ultraviolet (UV) excision repair pathway operates in B. subtilis sporangia. • The UV-edonuclease YwjD is a versatile repair protein that incise DNA damaged with a wide range of pyrimidine photodimers. • Exonuclease YpcP and low fidelity YqjH and YqjW DNA polymerases complement the incision repair event started by YwjD. • YwjD, YpcP and YqjH/YqjW, conform a novel error-prone repair pathway that protect B. subtilis sporangia from UV light. Abstract It has been shown that mutation frequency decline (Mfd) and nucleotide excision repair (NER) deficiencies promote UV-induced mutagenesis in B. subtilis sporangia. As replication is halted in sporulating B. subtilis cells, in this report, we investigated if this response may result from an error-prone repair event involving the UV-endonuclease YwjD and low fidelity (LF) DNA synthesis. Accordingly, disruption of YwjD generated B. subtilis sporangia that were more susceptible to UV-C radiation than sporangia of the WT strain and such susceptibility increased even more after the single or simultaneous inactivation of the LF DNA polymerases YqjH and YqjW. To further explore this concept, functional His 6 -tagged YwjD and Y-DNA polymerases YqjH and YqjW were produced and purified to homogeneity. In vitro repair assays showed that YwjD hydrolyzed the phosphodiester bond immediately located 5´-end of a ds -DNA substrate bearing either, cyclobutane pyrimidine dimers (CPD), 6-4 photoproducts (6-4 PD) or Dewar isomers (DWI). Notably, the 6-4 PD and DWI but not the CPDs repair intermediaries of YwjD were efficiently processed by the LF polymerase YqjH suggesting that an additional 5′→3′ exonuclease event was necessary to process PD. Accordingly, the LF polymerase YqjW efficiently processed the incision-excision repair products derived from YwjD and exonuclease YpcP attack over CPD-containing DNA. In summary, our results unveiled a novel non-canonical repair pathway that employs YwjD to incise PD-containing DNA and low fidelity synthesis contributing thus to mutagenesis, survival and spore morphogenesis in B. subtilis. [ABSTRACT FROM AUTHOR]

Abstract The aim of the present study is to determine the antibacterial and antibiofilm activity of alkaloids and flavonoids isolated from Curcuma species. To compare the potential of different constituents isolated from Curcuma species, the rhizomes of three species of Curcuma i.e. C. longa (Turmeric) , C. caesia (Black turmeric) and C. aromatica (Wild turmeric) were processed and analyzed. Flavonoids and alkaloids were extracted using methanol and acetic acid, respectively. Antibiofilm activity of alkaloids and flavonoids was determined using Gram-positive bacteria Staphylococcus aureus and Bacillus subtilis , which have unique properties to made biofilm very fast in solid surface as well as resist too many antibiotics. Results showed positive correlation with the concentration of alkaloids and flavonoids in both bacteria. The dispersal activity was further confirmed by the microscopic examination. In all the tests standard curcumin and camphor were used as a positive control. The flavonoid extract of C. aromatica showed pronounced zone of inhibition and antibiofilm activity against S. aureus in comparison to other two Curcuma species. In addition, alkaloid extract of C. aromatica exhibited maximum biofilm dispersal 89.22 ± 3.42% and antibiofilm activity 92.16 ± 0.76% against B. subtilis. C. aromatica which have a unique mechanism to inhibit the growth of bacteria in comparison to well explored C. longa. [ABSTRACT FROM AUTHOR]

Abstract Biofilms have been intensively investigated over the past decades. Bacillus subtilis is able to form highly structured colony biofilms, and as one of the most studied Gram-positive model organisms, has helped to decipher the complex genetic regulation of biofilms. Several methods have been developed to analyze the architecture of biofilms. In this paper, we describe a method which allows the analysis of the internal structures of biofilms by scanning electron microscopy (SEM). The method uses a modified freeze-fracturing of chemically fixed biofilm to generate defined, well-preserved fractures at millimeter-scale which allows to analyze systematically the internal biofilm structure from macro- to nano-scale. Highlights • Simple and reproducible method for biofilm cross-section analysis • Osmium fixation and dehydration of biofilms allows freeze-fractures. • Clean, non-frayed cross-sections by tearing the sample using forceps [ABSTRACT FROM AUTHOR]

Recent years have seen a remarkable increase in the global interest for mining isoprenoid-based fine-chemicals and nutraceuticals from GRAS (Generally regarded as Safe) status microbes capable of metabolizing complex carbon sources. In the present study, soil bacterium Bacillus subtilis was explored for its ability to produce hemiterpene-based alcohols, isopentenol (isoprenol and prenol) from simple to complex carbon sources. Isopentenol production in B. subtilis was enhanced by exploiting the over-expression of an endogenous 1-deoxy-D-xylulose-5-phosphate synthase ( dxs ) gene along with another native gene ADP-ribose pyrophosphatase ( nudF ). Genetic modulation enhanced isopentenol production in the recombinant strain (MTCC121-DxNu) by two-folds over the wild type strain. Further, the modulation of physico-chemical factors such as temperature (25 °C), pH regulator (K 2 HPO 4 ) and carbon source (sorbitol) improved protein expression and isopentenol production in the recombinant strain. The maximum production of isopentenol achieved was ∼2100 μg L −1 in shake flask containing Luria Broth (LB) with 0.1 M Sorbitol, 0.2 M K 2 HPO 4 at 25 °C, whereas, the non-detoxified rice-straw hydrolysate which is a low-cost substrate yielded 640 μg L -1 of isoprenol. This proof-of-concept study can be scaled up for the economical production of other commercially important isoprenoid-based flavors and pharmaceuticals from industrially competent microbial strains. [ABSTRACT FROM AUTHOR]

Probiotics can improve broiler performance and reduce pathogens. Because the hatchery can be a source of contamination, delivering probiotics to the embryo before hatch is desirable. To date, probiotics have primarily been injected into eggs manually. Therefore, the objective of this study was to deliver various probiotic bacteria into broiler hatching eggs using an automated commercial in ovo injection system to evaluate hatchability of fertile eggs (HF). Three separate experiments were conducted using Lactobacillus acidophilus, Bacillus subtilis, or Bifidobacterium animalis. In each experiment, 7 treatments (non-injected control; dry punch control; diluentinjected control; and injections of 10³ cfu, 104 cfu, 105 cfu, or 106 cfu of bacteria/50 μL of diluent) were evaluated using 10 replicates per treatment. For each experiment, 2,490 eggs were obtained from a commercial hatchery. Eggs were incubated under standard incubation conditions. At 10 d of incubation (doi), eggs were candled, and infertile eggs were removed. On 18 doi, all eggs were injected with the appropriate treatment using an automated in ovo injection system. Once all eggs were injected, they were transferred to hatching baskets and placed into the hatcher. On 21 doi, chicks were removed from the hatcher, counted, and weighed. Hatch residue analysis was conducted to determine infertile, early dead, mid dead, late dead, pipped, cracked, contaminated, and cull chick statuses of all unhatched eggs. Injecting L. acidophilus, even at a concentration as high as 106 cfu/50 μL, did not impact hatch residue analysis (P > 0.05). However, HF was significantly less for eggs treated with B. subtilis than for control eggs (P < 0.0001). For the non-injected control, HF was 91%, but as concentration of B. subtilis increased, HF decreased to as low as 1.67% for the 105 cfu treatment. Late deads, pipped, and contaminated egg percentages were higher, and chick BW was lower for B. subtilis treatment groups compared to controls. In conclusion, L. acidophilus and B. animalis but not B. subtilis, appear to be suitable candidates for in ovo injection as probiotics. [ABSTRACT FROM AUTHOR]

[Display omitted] • Jackfruit seed starch (JFSS) consisted of a high amount of resistant starch which could potentially use as a prebiotic. • B. subtilis stimulated the growth of L. plantarum in JFSS. • B. subtilis could help L. plantarum in the saccharification of complex starch. • Co-fermentation of B. subtilis and L. plantarum increased the yield of lactic acid production. Despite the exploration towards the environmentally friendly manufacturing process, two main challenges remain for lactic acid synthesis by microbial fermentation: resource cost and production efficiency. To alleviate environmental issues, lower raw material costs, and increase lactic acid manufacturing efficiency, this work aimed to evaluate characteristics of jackfruit seed starch (JFSS) extracted from fruit waste and explore the efficiency of lactic acid generation by co-fermentation of L. plantarum and B. subtilis in JFSS. JFSS consisted of a high amount of resistant starch and amylose, which was thermostable and displayed type A x-ray crystallization. Co-fermentation using JFSS as a substrate stimulated the growth of L. plantarum and enhanced lactic acid production over monocultures of L. plantarum and B. subtilis with insignificant by-product output. This study was valuable for improving lactic acid production efficiency and exploring the interaction between L. plantarum and B. subtilis. [ABSTRACT FROM AUTHOR]

In view of the growing concern about improving the characteristics and durability of cementitious materials, additions of bacteria, mainly of the genus Bacillus , are being studied as pore and crack filling through calcium carbonate precipitation (CaCO 3 ). In this sense, the present study tested the strain B. subtilis AP91, isolated from rice leaves of the early Agulha variety, in the precipitation of CaCO 3 by means of the change of pH during the formation of biofilm, in order to verify the potential of use of this bacterium to close pores and cracks in cementitious materials. To this end, the strain B. subtilis AP91 was inoculated in the B4 precipitation medium. The analysis of bacterial biofilm production and the evaluation of the morphology of precipitated crystals were performed using a Scanning Electron Microscope (SEM) and CaCO 3 was quantified by the difference of mass retained on the filter with 2 μm micropores. The results showed that the bacterium B. subtilis AP91 has high capacity for CaCO 3 precipitation, and may have advantageous applications in the closure of pores and cracks in cementitious materials. [ABSTRACT FROM AUTHOR]

In this study, the effect of adaptation of B. subtilis to sphalerite and galena with respect to the selective flotation of sphalerite from a sphalerite-galena synthetic mixture has been examined. The changes in the surface charge of the mineral and the bacterium, cell wall components and the profiles of secreted proteins are discussed. The protein profiles of the unadapted and adapted cells are found to differ distinctly, both qualitatively and quantitatively, with impact on the selective flotation of sphalerite and galena. Electrokinetic measurements show shifts in the iso-electric points of not only B. subtilis but also of the chosen minerals after adaptation. Additionally, the zeta potential of B. subtilis is found to become less negative after bacterial adaptation to the chosen sulfide minerals, while it showed an increase in the magnitude of surface negative charge after various enzymatic treatments. The change in the surface morphology and cell wall components such as phosphate, uronic acid and acetylated sugars of the bacterial species during adaptation to sphalerite and galena has been assessed. Selective flotation tests on a synthetic mixture of galena and sphalerite confirm that sphalerite can be preferentially floated from galena in the presence of the insoluble fraction of lysed B. subtilis cells initially adapted to sphalerite, with a high selectivity index. [ABSTRACT FROM AUTHOR]

The aim of this study was to develop a bacteriocin-producing QPS (Qualified Presumption of Safety) status Bacillus strain as a starter culture for fermented soybean foods as well as food preservation with improved safety and organoleptic qualities. Strain SN7 isolated from Meju , a fermented soybean product of Korea, was selected based on antimicrobial activity against pathogens such as B. cereus and production of bacteriocin. The selected strain SN7 was identified as B. subtilis . Safety assessments of B. subtilis SN7 (hemolytic activity, virulence traits, and antibiotic resistance) indicated that B. subtilis SN7 does not present a risk to human health, and this new isolate can be confidently recommended as a safe starter culture for the food industry. Cheonggukjang , a traditional fermented soybean food of Korea, fermented using B. subtilis SN7 showed high amino-type nitrogen content with good sensory characteristics. As a controlling agent of B. cereus in culture medium and in a food model of Cheonggukjang , B. subtilis SN7 efficiently inhibited growth of B. cereus vegetative cells and inactivated germination of B. cereus spores. Furthermore, B. cereus was not detected in Cheonggukjang stored at 4 °C for 6 months. B. cereus was easily detected in fermented food during storage at low temperature, as endo-spores of B. cereus are resistant to various treatments such as heat treatment and can grow even at 4–5 °C. These results suggest that bacteriocin-producing B. subtilis SN7 has great potential as a controlling agent of B. cereus and as a starter culture in Cheonggukjang . [ABSTRACT FROM AUTHOR]

A study was conducted to evaluate the potential of Bacillus subtilis -based probiotic to decrease crude protein (CP) requirement of broiler chicks. Growth performance, carcass, and meat quality characteristics, digestive tract development and ileal digestibility of CP were investigated using a total of 720 one-day-old commercial mixed sex broiler chicks. The recommended CP (CP100) or 2% below the recommended CP (CP98) were tested in the presence or absence of 0.2 g/kg of B. subtilis (0.8×10 9 cfu/g) in a 2×2 factorial arrangement of treatments in a completely randomized design. Broiler chicks were randomly assigned to 4 dietary treatments with 6 replicate pens per treatment and 30 broiler chicks per pen. Basal diets of starter, grower, and finisher were formulated according to the recommendations for commercial broiler chicks. Bacillus subtilis supplementation did not affect growth performance of broiler chicks. However, dietary CP level decreased ( P <0.05) body weight gain and feed efficiency. Broiler chicks supplemented with B. subtilis had a greater ( P <0.05) fillet weight with no differences observed for other carcass characteristic measurements. Adding B. subtilis had no effect on the meat quality measurements; however, dietary CP reduced ( P <0.05) meat water holding capacity. Also, B. subtilis deepened ( P <0.05) jejunum crypts and improved ( P <0.05) ileal CP digestibility. The results obtained from this study have enough evidence to assume that B. subtilis supplementation had beneficial effect on jejunum morphology and can reduce the adverse effect of dietary CP reduction. It may be concluded that the alteration in gastrointestinal morphological characters because of probiotic use was positively reflected on better CP ileal digestibility and the improved feed efficiency. [ABSTRACT FROM AUTHOR]

Culture medium elements were analysed by a screening DoE to identify their influence in surfactin specific production by a surfactin constitutive overproducing Bacillus subtilis strain. Statistics pointed the major enhancement caused by high glutamic acid concentrations, as well as a minor positive influence of tryptophan and glucose. Successively, a central composite design was performed in microplate bioreactors using a BioLector®, in which variations of these impressive parameters, glucose, glutamic acid and tryptophan concentrations were selected for optimization of product-biomass yield (Y P/X ). Results were exploited in combination with a RSM. In absolute terms, experiments attained an Y P/X 3.28-fold higher than those obtained in Landy medium, a usual culture medium used for lipopeptide production by B. subtilis . Therefore, two medium compositions for enhancing biomass and surfactin specific production were proposed and tested in continuous regime in a bubbleless membrane bioreactor. An Y P/X increase of 2.26-fold was observed in bioreactor scale. [ABSTRACT FROM AUTHOR]

Extracellular polymeric substances (EPS) matrix in biofilm poses important functions such as a diffusion barrier to antimicrobial agents so that biofilm cells are more difficult to completely eliminate. Therefore, biofilm cells exhibit enhanced resilience unlike planktonic cells, and are more difficult to completely eliminate. In order to obtain a comprehensive understanding of bacterial adhesion to surfaces, knowledge of the composition and conformational properties of EPS produced during growth and biofilm formation is required, since their adhesive and conformational properties remain poorly understood at molecular level. Present study has provided further insights into identifying compositional and conformational properties of EPS produced by planktonic and biofilm cells of B. subtilis and P. aeruginosa . Various spectroscopy analyses showed that EPS produced by the two different species were chemically dissimilar. More proteinaceous compounds were present in EPS from B. subtilis , while EPS from P. aeruginosa were characterized by greater carbohydrate components. However, relative proportions of polysaccharides and/or proteins constituents varied with the growth mode of the bacteria. AFM was then used to probe the adhesive nature of EPS produced by the bacteria by using Single Molecule Force Spectroscopy (SMFS). Comparison of the two bacterial species indicated that the presence of polysaccharides promoted the adhesion strength of the EPS while proteins had lesser adherence effects. Comparison of the two growth modes for the same bacterial strain also indicated that greater EPS production and enhanced cellular adhesion are associated with biofilm growth. [ABSTRACT FROM AUTHOR]

The batch macroscopic experiments showed that the biosorption kinetics of Sr(II) on Bacillus subtilis can be fitted by pseudo-second-order kinetic model very well, and adsorption isotherms can be satisfactorily fitted by Langmuir model with high correlation coefficient (R 2 > 0.995). The independent of ionic strength of Sr(II) biosorption on B. subtilis at pH 2.0–11.0 indicated the inner-sphere surface complexation. The maximum adsorption capacity of Sr(II) on B. subtilis calculated from Langmuir model at pH 5.0 and 293 K was 49.75 mg/g. The fitted results of the surface complexation modeling revealed that the biosorption of Sr(II) on B. subtilis can be simulated by diffuse layer modeling with two inner-sphere surface complexes such as SOSr + and SOSr(OH) 2 − species. Theses observation indicated that B. subtilis can be regarded as a promising bio-adsorbent candidate for the preconcentration and immobilization of radionuclides from aqueous solutions in the environmental remediation. [ABSTRACT FROM AUTHOR]

The biosorption of Eu(III) and U(VI) on Bacillus subtilis ( B. subtilis ) as a function of reaction time, pH, ionic strength, temperature was investigated by macroscopic and modeling techniques. The macroscopic experiments indicated that the biosorption kinetics and isotherms of Eu(III) and U(VI) on B. subtilis can be satisfactorily fitted by pseudo-second-order kinetic model and Langmuir model, respectively. No effect of ionic strength revealed that the inner-sphere surface complexation dominated the biosorption of Eu(III) and U(VI) onto B. subtilis . The maximum sorption capacity of B. subtilis calculated from Langmuir model at pH 4.5 and 298 K was 58.80 and 90.91 mg/g for Eu(III) and U(VI), respectively. According to the surface complexation modeling, the biosorption of Eu(III) and U(VI) on B. subtilis can be simulated by diffuse layer modeling with three inner-sphere surface complexation sites such as phosphoryl, carboxyl and hydroxyl groups. The findings presented herein suggested that B. subtilis is a promising bio-adsorbent for the preconcentration and retardation of radionuclides in the environmental remediation strategy such as permeable reactive barrier. [ABSTRACT FROM AUTHOR]

Hydraphiles are synthetic amphiphiles that form ion-conducting pores in liposomal membranes. These pores exhibit open-close behavior when studied by planar bilayer conductance techniques. In previous work, we showed that when co-administered with various antibiotics to the DH5α strain of Escherichia coli , they enhanced the drug’s potency. We report here potency enhancements at low concentrations of hydraphiles for the structurally and mechanistically unrelated antibiotics erythromycin, kanamycin, rifampicin, and tetracycline against Gram negative E. coli (DH5α and K-12) and Pseudomonas aeruginosa , as well as Gram positive Bacillus subtilis . Earlier work suggested that potency increases correlated to ion transport function. The data presented here comport with the function of hydraphiles to enhance membrane permeability in addition to, or instead of, their known function as ion conductors. [ABSTRACT FROM AUTHOR]

Quantum dot (QD) nanoparticles can coexist with Cu 2+ in soil and can adsorb Cu 2+ entering into bacterial cells, thereby promoting cellular copper accumulation and enhancing the combined toxicity of these two chemicals. Toxicity test results on Bacillus subtilis showed that the addition of safe concentrations of MPA-CdTe QDs to Cu 2+ culture (levels under IC 50 value) resulted in higher toxicity with about twofold reduction in cell viability and increased intracellular Cu content. ROS levels also increased by about 500%, and SOD activity was altered after QD addition. Treatment with Cu 2+ alone decreased the α-amylase activity of B. subtilis by 8%–35%. This finding was not affected by QD addition. Moreover, increased cellular copper concentration as a result of QD addition enhanced toxicity primarily by producing superoxide anions. However, this phenomenon did not interrupt the physical–biological responses of soil microbes. [ABSTRACT FROM AUTHOR]

This study discussed the effects of different bacterial concentrations and centrifugations on the antimicrobial efficacy of electrolyzed oxidizing (EO) water on Bacillus subtilis and Escherichia coli O157:H7. Overnight grown bacterial cultures were centrifuged 1 to 3 times and bacterial concentrations were adjusted to approximately 9 (high), 7 (medium), or 5 (low) log 10 CFU/mL. Antimicrobial efficacy of acidic EO water (AEW) and neutral pH EO water (NEW) containing 0.25–30 mg/L available chlorine was determined. In order to ascertain the effects of AEW and NEW on targeted pathogens, cellular properties at bio-molecular levels were also studied. The results showed that the susceptibility of both pathogens decreased significantly with increasing bacterial concentrations. AEW with 10, 0.25 and 0.25 mg/L and NEW with 30, 0.5 and 0.25 mg/L available chlorine were needed for high, medium and low bacterial concentrations, respectively to non-detectable levels by direct plating for E. coli O157:H7. B. subtilis was found more resistant to both EO water treatments and only 4.1 and 3.8 log reductions were achieved for AEW and NEW containing 30 mg/L available chlorine. On the other hand, it was observed that as centrifugation time increased, both bacteria became significantly more sensitive to EO water treatments. When centrifugation period increased from 1 to 3 times, additional 2.67 and 3.38 log E. coli O157:H7 reductions were observed for AEW and NEW treatments, respectively. A similar trend was observed for B. subtilis . DNA and protein leakage increased when pathogens were treated by AEW and NEW with increasing available chlorine concentration, but decreased DNA and protein leakage were observed with increased centrifugation times. These results indicate that initial bacterial concentration and the centrifugation time are two important factors and should be carefully considered in chlorine-based antimicrobial efficacy testing. [ABSTRACT FROM AUTHOR]

In the present study, probiotic Bacillus spores were used as a matrix for enzyme immobilization, because of their inherent resistance to extreme temperatures, UV irradiation, solvents and drying. An Escherichia coli– Bacillus subtilis shuttle vector (pHS-CotG-nit) was constructed for the spore surface display of the nitrilase from hyperthermophilic bacterium Thermotoga maritima MSB8. The successful display of CotG-nit fusion protein on the spore surface of B. subtilis was verified by western blot analysis and activity measurement. The optimal temperature and pH of the spore surface-dispalyed nitrilase were observed to be 50 °C and pH 8.0, respectively, which were higher than the free nitrilase (45 °C and pH 7.5). The analysis of thermal and pH stability indicated that the spore surface-displayed nitrilase retained 79% and 97% at 75 °C and pH 8.0 after 1 h of incubation, whereas it were 32% and 52%, respectively, for free nitrilase. Furthermore, the reusability experiments indicated that the activity of the spore surface-displayed nitrilase was not significantly decreased throughout the reusability process, which still retained 83% of the initial activity at the fifth cycle. Above all, these results suggested that surface display of enzymes on the spore of B. subtilis might be an effective method for enzyme immobilization and help to meet the ever-increasing industrial demand for preparation and stabilization of biocatalysts. [ABSTRACT FROM AUTHOR]

Rice mill polishing residue (RMPR), an abundant and cheap agro residue, was used as substrate for microbial growth of Bacillus subtilis MTCC 2423 by submerged fermentation process to produce surfactin. Nutrients present in the residue were sufficient to sustain the growth of the microorganism. Multi stage foam fractionation followed by acid precipitation was used to concentrate and recover the product. Recoverable yield of surfactin was 4.17 g/kg residue. Product recovered in the foamate accounted for 69% of the total yield. The residual broth containing ∼30% surfactin exhibited biological oxygen demand and chemical oxygen demand values of 23 and 69 mg/L respectively. The microbial growth data was correlated using three parameter sigmoid models. Surfactin synthesized had a predominance of molecular weight 1076 Da. Foam separation of copper using surfactin resulted in a maximum removal of 72.5%. [ABSTRACT FROM AUTHOR]

The rapid emergence of microbial drug resistance indicates the urgent need for development of new antimicrobial agents. Bacterial cell division machinery is considered as a promising antimicrobial target. Totarol is a naturally existing diterpenoid, which has the ability to restrain bacterial growth by perturbing the cell division. The present study was conducted to investigate the proteomic alterations in Bacillus subtilis as a consequence of totarol treatment to decipher its mechanism of action and possible molecular targets. Cellular proteome of the totarol treated B. subtilis AH75 strain was analyzed by using multiple complementary proteomic approaches. After the drug treatment, 12, 38 and 139 differentially expressed (1.5 fold change) proteins were identified using 2-DE, DIGE and iTRAQ analyses, respectively. In silico functional analysis of the identified differentially expressed proteins indicated a possible effect of totarol on the central metabolism for energy production, heme biosynthesis and chemotaxis. Interestingly, the primary dehydrogenases, which play a vital role in generating the reducing equivalent, were found to be repressed after totarol treatment indicating an apparent metabolic shutdown. Consequently, multiple cellular assays including resazurin assay and FACS analysis of 5-cyano-2,3-ditolyl tetrazolium chloride (CTC) staining confirmed the effect of totarol on respiratory activity and cellular metabolism. Biological significance The exact mechanism of action of totarol is still unclear and further investigations are essential to identify the molecular/cellular targets of this potential antimicrobial agent. The present study demonstrates the application of differential proteome to decipher the mechanism of action and molecular targets of totarol in B. subtilis. Our quantitative proteome analysis revealed that totarol induced alterations in the expression levels of 139 proteins (1.5 fold change and ≥ 2 peptides) in B. subtilis . Findings obtained from this study indicate that totarol treatment leads to metabolic shutdown by repressing the major central metabolic dehydrogenases in B. subtilis . In addition, expression levels of universal chaperone proteins, heme biosynthesis, and ribosomal proteins were found to be altered, which caused the filamentation of the bacteria. To the best of our knowledge, this is the foremost inclusive investigation describing totarol induced alterations in B. subtilis proteome and diverse physiological processes. We anticipate that this in depth proteomic study may contribute to a better understanding of the mode of action of totarol and its primary molecular and cellular targets. [ABSTRACT FROM AUTHOR]

One-electron oxidation of acetohydroxamic acid (aceto-HX) initially gives rise to nitroxyl (HNO), which can be further oxidized to nitric oxide (NO) or react with potential biological targets such as thiols and metallo-proteins. The distinction between the effects of NO and HNO in vivo is masked by the reversible redox exchange between the two congeners and by the Janus-faced behavior of NO and HNO. The present study examines the ability of aceto-HX to serve as an HNO donor or an NO donor when added to Escherichia coli and Bacillus subtilis subjected to oxidative stress by comparing its effects to those of NO and commonly used NO and HNO donors. The results demonstrate that: (i) the effects of NO and HNO on the viability of prokaryotes exposed to H 2 O 2 depend on the type of the bacterial cell; (ii) NO synergistically enhances H 2 O 2 -induced killing of E. coli, but protects B. subtilis depending on the extent of cell killing by H 2 O 2 ; (iii) the HNO donor Angeli׳s salt alone has no effect on the viability of the cells; (iv) Angeli׳s salt synergistically enhances H 2 O 2 -induced killing of B. subtilis , but not of E. coli ; (v) aceto-HX alone (1–4 mM) has no effect on the viability of the cells; (vi) aceto-HX enhances the killing of both cells induced by H 2 O 2 and metmyoglobin, which may be attributed in the case of B. subtilis to the formation of HNO and to further oxidation of HNO to NO in the case of E. coli ; (vii) the synergistic activity of aceto-HX on the killing of both cells induced by H 2 O 2 alone does not involve reactive nitrogen species. The effect of aceto-HX on prokaryotes under oxidative stress is opposite to that of other hydroxamic acids on mammalian cells. [ABSTRACT FROM AUTHOR]

B. subtilis can grow, survive, and cause spoilages of meat and potato samples. This situation represents both public health and economic concerns. The present work assessed the inhibitory effects of acetic and propionic acids in combination with Nisin (NS) in preventing meat and potato spoilage caused by B. subtilis. NS inactivated the contaminating microbe at 0.016 mg/ml, acetic and propionic acids at 0.13% v/v and 0.25% v/v respectively. NS (0.002 mg/ml) was combined with acetic acid at 0.065% v/v and propionic acid at 0.125% v/v to delay the rapid proliferation of the B. subtilis inoculated on meat and potato at 105 CFU/g. The samples were treated for 10 min and incubated for 10 day at 37 °C. Samples treated with purified water decreased the cell population to 4.21 log CFU/g after 10 min. While acetic, propionic, NS and 0.02N HCL show (3.68, 4.11, 4.05 and 4.15 log decreases). A further significant reduction (p < 0.05) happened after treatments with the combination of NS-acetic and NS-propionic acids (2.26 and 2.38 log CFU/g). DNA retardation analysis shows that neither NS nor acetic or propionic acid target DNA as alternative mechanism of action. At day 10, changes in the color of meat and potato samples treated with NS-organic acids were not significant (p < 0.05) when compared to the control. This is the first report showing the effectiveness of using NS, acetic and propionic acids concoction to control B. subtilis in meat and potato samples. [Display omitted] • Synergistic potential of Nisin with acetic and propionic acids against B. subtilis on Meat and Potato. • Cost-effective prevention of B. subtilis influence in meat and potato spoilage. • Formulation of consumer-friendly antibacterial cocktail. • An effective combination against spore forming organisms causing food spoilage. [ABSTRACT FROM AUTHOR]

Abstract: In this work we report on the simultaneous measurement of the hydrodynamic coefficient and the electric charge of single Bacillus subtilis spores. The latter has great importance in protein binding to spores and in the adhesion of spores onto surfaces. The charge and the hydrodynamic coefficient were measured by an accurate procedure based on the analysis of the motion of single spores confined by an optical trap. The technique has been validated using charged spherical polystyrene beads. The excellent agreement of our results with the expected values demonstrates the quality of our procedure. We measured the charge of spores of B. subtilis purified from a wild type strain and from two isogenic mutants characterized by an altered spore surface. Our technique is able to discriminate the three spore types used, by their charge and by their hydrodynamic coefficient which is related to the hydrophobic properties of the spore surface. [Copyright &y& Elsevier]

Abstract: This article reports the biosorption potential of Gum ghatti (Gg)-grafted-acrylic acid (AA) polymer and its susceptibility to biodegradation by Bacillus subtilis (BS) in two different liquid media, i.e. phosphate buffered saline (PBS) and mineral salt medium (MSM). The progress of biodegradation was monitored after every 15 days using FT-IR and SEM techniques. The degradation of the polymer was further evidenced by a loss of weight of 23.2% and 27% in BS-MSM and BS-PBS, respectively, after 60 days. The AA-grafted polymer was then utilized for the removal of Pb(II) and Cu(II) from aqueous solution. The adsorption isotherm data were studied using Langmuir, Freundlich, Temkin, Flory–Huggins and Dubinin–Kaganer–Radushkevich isothermal models. High values of correlation coefficients confirmed the applicability of Langmuir isotherm model used to determine the adsorption capacity of the AA-grafted polymer. The maximum adsorption capacity was found to be 84.74mg/g for Cu(II) and 310.55mg/g for Pb(II). Kinetic data were evaluated using pseudo first order, pseudo second order, Elovich, intraparticle diffusion and liquid film diffusion models. The experimental kinetic data fitted well with the pseudo second order rate model. [Copyright &y& Elsevier]

Abstract: Bacillus subtilis spores were deposited in high-density single layers on metal, glass, and polymer substrates using vacuum filtration followed by a wetted filter transfer step. Quantitative analysis of spore transfer was performed using culture-based and germinability assays, and spore distributions were observed with electron microscopy. [Copyright &y& Elsevier]

Abstract: This study examined antioxidant and antimicrobial activities of medium oat bran treated with four polysaccharide enzymes viscozyme, cellulase, alpha-amylase, and amyloglucosidase. The effects of these enzymes on the release of phenolic acids were determined using reverse-phase HPLC chromatography. Antioxidant assays showed that enzyme pre-treatments significantly increased the hydroxyl radical (HO ) scavenging activity of all bran samples (16.6–20.0μM propyl gallate equivalents (PGE)/g bran) relative to untreated bran (13.3±1.8μM PGE/g). The order of activity was cellulase≈viscozyme>amyloglucosidase≈alpha-amylase. The DPPH free radical inhibitory activities of brans pre-treated with cellulase and amyloglucosidase, 43.0% and 45.0%, respectively were higher than inhibition by untreated bran 21.7% (P<0.05). In the linoleic acid (LA) autoxidation assay, three of the treated and untreated brans similarly inhibited LA oxidation, while viscozyme pre-treated bran had no activity. HPLC analysis showed an increase in free phenolic acids, and this was more pronounced for ferulic and caffeic acids. In the antimicrobial assay, brans pre-treated with viscozyme and cellulase similarly inhibited the growth of Escherichia coli compared to untreated bran (P<0.05), while viscozyme- and alpha-amylase-treated brans enhanced the growth of Bacillus subtilis, a non-pathogenic bacteria strain that has been used as a pro-biotic. [Copyright &y& Elsevier]

Abstract: CTBT (7-chlorotetrazolo[5,1-c]benzo[1,2,4]triazine) is an antifungal and chemosensitizing agent that induces oxidative stress in yeast and filamentous fungi and enhances the cytotoxic activity of 5-fluorocytosine and azole antimycotics. This study reports the effect of CTBT on bacterial cells. CTBT inhibited the growth of both Gram-positive and Gram-negative bacterial species. The action of CTBT was bactericidal. In Escherichia coli, CTBT induced an increased formation of reactive oxygen species (ROS), as determined with a ROS specific probe 2′,7′-dichlorodihydrofluorescein diacetate. In zone inhibition assays, bacterial cells were more sensitive to CTBT compared with paraquat, menadione and hydrogen peroxide. The deletion of oxidative stress related genes resulted in increased susceptibility of E. coli mutant strains to CTBT treatment. Exogenous antioxidants such as ascorbic acid, cysteine and glutathione exhibited a protective effect against the growth inhibition induced by CTBT. CTBT may be a useful tool in the studies of ROS generation, oxidant sensing and oxidative stress response in different bacterial species. [Copyright &y& Elsevier]

Abstract: The aim of this work was to investigate the lipopeptides aggregation behavior in single and mixed solutions in a wide range of concentrations, in order to optimize their separation and purification following the two-step ultrafiltration process and using large pore size membranes (up to MWCO=300kDa). Micelle size was determined by dynamic light scattering. In single solutions of lipopeptide both surfactin and mycosubtilin formed micelles of different size depending on their concentration, micelles of average diameter=5–105nm for surfactin and 8–18nm for mycosubtilin. However when the lipopeptides were in the same solution they formed mixed micelles of different size (d =8nm) and probably conformation to that formed by the individual lipopeptide, this prevents their separation according to size. These lipopeptides were purified from fermentation culture by the two-step ultrafiltration process using different MWCO membranes ranging from 10 to 300kDa. This led to their effective rejection in the first ultrafiltration step by membranes with MCWO=10–100kDa but poor rejection by the 300KDa membrane. The lipopeptides were recovered at 90% purity (in relation to protein) and with 2.34 enrichment in the permeate of the second ultrafiltration step with the 100KDa membrane upon addition of 75% ethanol. [Copyright &y& Elsevier]

Abstract: The present study describes the efficiency of heterogeneous photocatalytic reactor for the inactivation of three air born bacteria, Escherichia coli, Bacillus subtilis and Staphylococcus aureus using metal modified TiO2 photocatalysts and blacklight irradiation. The catalysts were prepared by photodeposition of silver, palladium or iron on commercial TiO2, immobilized on glass plates. X-ray photoelectron spectroscopy analysis was applied to determine the atomic percentage and species of each metal on the TiO2 surface, showing that 85% of silver, 73% of palladium and 45% of iron were present in metallic form on TiO2 surface. The plates were positioned on the inner lateral walls of a chamber through which the contaminated air flow passed for disinfection. Irradiation of bare TiO2 resulted in 50% inactivation of E. coli while 41% and 35% inactivation of B. subtilis and S. aureus were obtained, respectively. When metal modified TiO2 was applied, the inactivation of B. subtilis was improved to 91% using Pd–TiO2 while of S. aureus was improved to 94% with Fe–TiO2, showing in this case no significant difference when compared to Ag–TiO2 and Pd–TiO2. In contrast, inactivation of E. coli was not significantly increased when metal modified TiO2 was used, ranging from 47% to 57%. [Copyright &y& Elsevier]

Abstract: Recently, a bubbleless membrane bioreactor (BMBR) has been successfully developed for biosurfactant production by Bacillus subtilis[1]. In this study, for the first time, continuous culture were carried out for the production of surfactin in a BMBR, both with or without a coupled microfiltration membrane. Results from continuous culture showed that a significant part of biomass was immobilized onto the air/liquid membrane contactor. Immobilized biomass activity onto the air/liquid membrane contactor was monitored using a respirometric analysis. Kinetics of growth, surfactin and primary metabolites production were investigated. Planktonic biomass, immobilized biomass and surfactin production and productivity obtained in batch culture (3L) of 1.5 days of culture were 4.5gDW, 1.3gDW, 1.8g and 17.4mgL−1 h−1, respectively. In continuous culture without total cell recycling (TCR), the planktonic biomass was leached, but immobilized biomass reached a steady state at an estimated 6.6gDW. 11.5g of surfactin was produced after 3 days of culture, this gave an average surfactin productivity of 54.7mgL−1 h−1 for the continuous culture, which presented a surfactin productivity of 30mgL−1 h−1 at the steady state. TCR was then investigated for the continuous production, extraction and purification of surfactin using a coupled ultrafiltration step. In continuous culture with TCR at a dilution rate of 0.1h−1, planktonic biomass, immobilized biomass, surfactin production and productivity reached 7.5gDW, 5.5gDW, 7.1g and 41.6mgL−1 h−1 respectively, after 2 days of culture. After this time, biomass and surfactin productions stopped. Increasing dilution rate to 0.2h−1 led to the resumption of biomass and surfactin production and these values reached 11.1gDW, 10.5gDW, 7.9g and 110.1mgL−1 h−1, respectively, after 3 days of culture. This study has therefore shown that with this new integrated bioprocess, it was possible to continuously extract and purify several grams of biosurfactant, with purity up to 95%. [Copyright &y& Elsevier]

Abstract: In this work we present a refractive index (RI) sensor based on a sub-wavelength holographic diffraction grating. The sensor chip was fabricated by dry etching of the finely spaced (d =428nm) diffraction grating in SiO x doped diamond like carbon (DLC) film. It is shown that employing a fabricated sensor chip, and using the proposed method of analysis of data, one can inspect kinetics of processes in liquids occurring in the vicinity of the grating surface. The method is based on the spectral composition analysis of polarized polychromatic light reflected from the sub-wavelength diffraction grating. The RI measurement system was tested with different model liquid analytes including 25wt.%, 50wt.% sugar water solutions, 10°C, 50°C distilled water, also Gram-positive bacteria Bacillus subtilis interaction with ion-permeable channels forming antibiotic gramicidin D and a murolytic enzyme lysozyme. Analysis of the data set of specular reflection spectra enabled us to follow the kinetics of the RI changes in the analyte with millisecond resolution. Detectable changes in the effective RI were not worse than Δn =10−4. [Copyright &y& Elsevier]

Abstract: This experiment was carried out to evaluate the effects of the probiotic Bacillus subtilis on survival, growth, biochemical constituents and energy utilization in Macrobrachium rosenbergii PL. Experimental diets were the same in all, except for the variation in probiotic levels. The probiotic B. subtilis was used at 0% (diet 1), 1% (diet 2), 2.0% (diet 3), 3.0% (diet 4) and 4.0% (diet 5) inclusion in the experimental diets. These diets were fed to M. rosenbergii PL for a period of 90days. The growth parameters, such as survival, weight gain, specific growth rate, feed conversion efficiency and protein efficiency rate were significantly (P <0.05) higher in 3% B. subtilis incorporated diet fed PL followed by other experimental groups than the control. Similarly the biochemical constituents of the protein, amino acid, carbohydrate, lipid and ash content were significantly (P <0.05) higher in 3% B. subtilis incorporated diet fed PL. The energy utilization parameters, such as feeding rate, absorption rate, conversion rate and metabolic rate were significantly (P <0.05) higher in 3% B. subtilis incorporated diet fed PL. From the results of this experiment, we conclude that B. subtilis can be used as a probiotic in M. rosenbergii culture, to enhance the survival, growth and improved energy utilization performance. [Copyright &y& Elsevier]

Abstract: Pulsed Light (PL) uses intense flashes of white light rich in ultraviolet (UV) light for decontamination. A log-reduction higher than 5 was obtained in one flash and at fluences lower than 1.8J/cm2 on spores of a range of spore-forming bacteria, of vegetative cells of non-spore-forming bacteria and on yeasts spread on agar media. Vegetative cells were more sensitive than spores. The inactivation by PL of Bacillus subtilis, B. atrophaeus, B. cereus, Geobacillus stearothermophilus, and Aspergillus niger spores sprayed on polystyrene was similar. The inactivation by PL of B. subtilis and A. niger spores sprayed on glass was slightly lower than on polystyrene. No alteration of the spore structures was detected by scanning electron microscopy for both PL treated B. subtilis and A. niger spores. The inactivation of spores of B. subtilis, B. atrophaeus, B. cereus and B. pumilus by PL or by continuous UV–C at identical fluences was not different, and was much higher by PL for A. niger spores. The increase in the input voltage of the lamps (which also increases the UV–C %) resulted in a higher inactivation. There was no correlation between the resistance to heat and the resistance to PL. The relative effect of UV–C radiations and light thermal energy on PL inactivation was discussed. [Copyright &y& Elsevier]

Abstract: The production of biosurfactant by Bacillus subtilis LSFM-05 was carried out using raw glycerol, obtained from a vegetable oil biodiesel plant in Brazil, as the sole carbon source. Production of the biosurfactant was carried out in a 15-L bench-top fermentor and the surfactant was obtained from the foam produced. The crude surfactant was purified by silica gel column chromatography with a yield of 230mg of the purified biosurfactant per liter of foam. TLC, IR spectroscopy, 1H and 13C NMR and Fourier transform ion cyclotron resonance mass spectrometry with electrospray ionization (ESI-FTMS) were used to characterize the purified surfactant. The isolated surfactant was identified as a surfactin lipopeptide. MS/MS data identified the amino acid sequence as GluOMe-Leu-Leu-Asp-Val-Leu-Leu and showed that the fatty acid moiety contained 14 carbons in iso, anteiso or normal configurations. The critical micelle concentration of the C14/Leu7 surfactin was 70μM, with emulsification efficiency after 24h (E 24) of 67.6% against crude oil. Raw glycerol represents an abundant and renewable carbon source and provides an opportunity for reducing the cost of biosurfactant production and may add value to biodiesel production by creating new commercial applications for this by-product. [Copyright &y& Elsevier]

Abstract: Large number of papers has been published recently on the eleventh group metallic elements such as Ag, Au and Cu. Our study was focused on biosynthesis of silver nanoparticles, their morphology, reactivity and stability. We were interested to check these properties in two different samples, S1 and S2, respectively. The biosynthesis of silver nanoparticles was achieved by reacting the samples with 1mM concentration of silver nitrate, one involves bacteria (S1) and the other involves the plant extract (S2). Spectrophotometric analysis revealed that the particles exhibited two peaks, one at 440nm (for S1) and the other at 390nm (for S2). It is well known that longer wavelength corresponds to increase in particle size. Since, S1 has got a longer wavelength; it is not known, whether it forms isolated particles or agglomerates? Morphological characterization has been done by adopting the procedures of Negative staining and Wedge smear preparation methods. This hybrid method may be of interest to study agglomerated particles. Microscopic examination of the smear S1 shows predominantly triangular or hexagonal shaped agglomerated particles which were not observed in S2. Hence further characterization was done using SEM, EDAX and XRD. The S2 particles were in the range of 45–70nm and were stable for even four months. This study indicated that particle size can be controlled from micrometer to nanometer size by varying biological reductants. [Copyright &y& Elsevier]

Abstract: Recent evidence suggests that cell-to-cell difference at the gene expression level is an order of magnitude greater than previously thought even for isogenic bacterial populations. Such gene expression heterogeneity determines the fate of individual bacterial cells in populations and could also affect the ultimate fate of populations themselves. To quantify the heterogeneity and its biological significance, quantitative methods to measure gene expression in single bacterial cells are needed. In this work, we developed two SYBR Green-based RT-qPCR methods to determine gene expression directly in single bacterial cells. The first method involves a single-tube operation that can analyze one gene from each bacterial cell. The second method is featured by a two-stage protocol that consists of RNA isolation from a single bacterial cell and cDNA synthesis in the first stage, and qPCR in the second stage, which allows determination of expression level of multiple genes simultaneously for single bacterial cells of both gram-positive and negative. We applied the methods to stress-treated (i.e. low pH and high temperature) Escherichia coli populations. The reproducible results demonstrated that the method is sensitive enough not only for measuring cellular responses at the single-cell level, but also for revealing gene expression heterogeneity among the bacterial cells. Furthermore, our results showed that the two-stage method can reproducibly measure multiple highly expressed genes from a single E. coli cell, which exhibits important foundation for future development of a high throughput and lab-on-chips whole-genome RT-qPCR methodology for single bacterial cells. [Copyright &y& Elsevier]

Abstract: Bacillus subtilis strains expressing tetanus toxin fragment C (TTFC) were tested as vaccine candidates against tetanus in adult mice. Mice received three intranasal (IN) exposures to 109 spores or 108 vegetative cells of B. subtilis expressing recombinant TTFC. Immunized mice generated protective systemic and mucosal antibodies and survived challenge with 2× LD100 of tetanus toxin. Isotype analysis of serum antibody indicated a balanced Th1/Th2 response. Lyophilized vaccines stored at 45°C for ≥12 months, remained effective. Immunized conventional and SCID mice remained well, and no histological changes in brain or respiratory tract were detected. Lyophilized/reconstituted B. subtilis tetanus vaccines administered IN to mice appear safe, heat-stable, and protective against lethal tetanus challenge. [ABSTRACT FROM AUTHOR]

Abstract: The cytoskeletal protein, FtsZ plays a pivotal role in prokaryotic cell division and is present in majority of the bacterial species. In recent years, inhibitors of FtsZ have been identified that may function as lead compounds for the development of novel antimicrobials. It has been found that curcumin, the main bioactive component of Curcuma longa, inhibits Bacillus subtilis and Escherichia coli growth by inhibiting FtsZ assembly. Though it is experimentally established that curcumin inhibits FtsZ polymerization, the binding site of curcumin in FtsZ is not known. In this study, interaction of curcumin with catalytic core domain of E. coli and B. subtilis FtsZ was investigated using computational docking. [ABSTRACT FROM AUTHOR]