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[Display omitted] • Bacillus sphaericus act as reducing and capping agent for formation of nickel nanoparticle (Bs@NiNPs). • Bs@NiNPs characterized by XRD, FTIR, SEM, TEM and AFM analysis. • The Bs@ninps mainly sphere-shaped, with an average size of 23 ± 2.00 nm. • Bs@NiNPs showed promising larvicidal activities on ticks and mosquito larvae. • Bs@NiNPs exhibited promising detoxifying enzyme activities. In this study, we use extracellular metabolites of Bacillus sphaericus culture for the biosynthesis of nickel nanoparticles (BS@NiNPs) and potential larvicidal activity against Anopheles subpictus and Culex quinquefasciatus as well as against Rhipicephalus (Boophilus) annulatus (adult cattle tick). The extracellular metabolites derived from B. sphaericus culture acts as strong reducing and capping agents, allowing biosynthesis of the BS@NiNPs. Characterization of the synthesized NiNPs was carried out using various techniques, including UV–vis spectroscopy, atomic force microscopy (AFM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) and X-ray diffraction (XRD). The FTIR spectroscopy analysis revealed significant peaks at specific wavenumbers (3435, 2923, 1646, 1406, and 1115 cm−1), indicating the presence of functional groups from biomolecules involved in the synthesis of BS@NiNPs. XRD analysis confirms well-defined peaks observed at 2 θ = 31.72°, 45.40°, 56.43°, and 75.32°, which correspond to the lattice planes of 100, 101, 102, and 103 reflections, respectively. SEM and TEM images showed that the NiNPs exhibited spherical to oval shapes with clustered morphology with an average diameter of the grain size is about 23 ± 2.00. The BS@NiNPs exhibited significant parasitic action against A. subpictus and C. quinquefasciatus as well as adult cattle tick R. (B) annulatus. It is noteworthy that bacterial pathogens such as Bacillus species are commonly used for vector bio-control management due to their spore-forming characteristics. Therefore, the toxicity of BS@NiNPs-treated mosquito larvae and cattle ticks was analyzed for stress-related enzyme activities, including carboxylesterases, β-glucosidases, and glutathione S-transferases. In summary, our work shows that BS@NiNPs have the potential to be an efficient larvicide against ticks and mosquito larvae. The results of this study help to design environmentally benign and long-lasting methods for biological control, addressing the problems posed by vector-borne diseases. [ABSTRACT FROM AUTHOR]

The Culex (Cx.) pipiens mosquito is the main vector of Filariasis and Rift Valley Fever in Egypt. Bacillus (B.) sphaericus is a mosquitocidal bacterium that was recently developed as a commercial larvicide and is used to control pestiferous and vector mosquitos worldwide. Whereas B. sphaericus is highly active against larvae of Culex. The 4th larval instar of Cx. pipiens were dissected at 2, 10 and 14 hrs post-treatment with B. sphaericus, then the alimentary canal was fixed in 5% glutaraldehyde. Samples were dehydrated in an ethanol series, filtrated with epoxy resin, and stained with uranyl acetate. Semi-thin sections were stained with toluidine blue dye and then examined with 100X light microscopy (LM). The transverse sections (TS) of the mid and hindgut were examined by Transmission Electron Microscopes (TEM). The ultrastructural changes detected showed apoptosis, shrinkage, detachment from neighbours, nuclear degranulation, a number of vacuoles developed, and the bacteria began to penetrate the larval lumen. The damage to the midgut epithelium of the fourth larval instar of Cx. pipiens caused by B. sphaericus infection have an effect on the proliferation and differentiation of intestinal stem cells (ISC) in the midgut epithelium. It occurred simultaneously with a slight increase in cell division. Precursor stems cell proliferation and differentiation could replace the destroyed epithelial cells. The ISC regenerates the architecture of the midgut epithelium, thereby accelerating tissue repair. It was found that the number of stem cells and nuclei increase over time post-bacterial infection. [ABSTRACT FROM AUTHOR]

Potatoes are one of the most important food products in the world and considered a main human nutrition sources source. Potato tuber moth (Phthorimaea operculella Zeller (PTM) (Lepidoptera: Gelechiidae)) causes remarkable economic losses to important crop, both in field and under storage conditions In this study, the insecticidal efficiency of the following bioagents: Brevibacillus brevis (FD-1), Bacillus atrophaeus (FD 17), Bacillus sphaericus (FD 49), Bacillus cereus (FD 63), Vibrio hollisae (FD 70), Bacillus thuringiensis subsp. kenyae (FDP 8) bacteria strains and Beauveria bassiana fungal isolate (ET 10), were evaluated on their efficacy to control P. operculella, under controlled conditions. In addition to insecticidal efficacy evaluations, analyses were also carried out to determine the differences between bioagents action mode: (1) uptake (ingestion as a gastric poison) and (2) contact. For (1), 20 larvae were fed on the tubers immersed in these suspensions to analyze efficacy by ingestion; for (2), suspensions of 1x108 CFU/ml of bacteria and 5.7x105 conidia/ml of fungus were prepared and sprayed to 20 larvae. FD-63 (91.67%) and FD-17 (88.33%) taken up by diet gave the most effective results against the pest. [ABSTRACT FROM AUTHOR]

[Display omitted] • Bacillus sphaericus was used for the green reduction of GO. • Successful reduction of GO was confirmed by characterizations. • Specific O H, C O and C O C bonds were reduced. • Green reduction of GO had good capacitance and conductivity. While chemical methods are often used to convert graphene oxide (GO) to reduced graphene oxide (RGO), chemical reduction is often environmentally unfriendly due to the high toxicity of many chemical reducing agents. To address this limitation, Bacillus sphaericus was used here for the green reduction of GO to RGO. Successful reduction was confirmed by various advanced characterization techniques including Ultraviolet–Visible (UV–vis), X-ray Powder Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Raman spectroscopy, X-ray Photoelectron Spectroscopy (XPS) and Scanning Electron Microscope and Energy Dispersive Spectrometer (SEM-EDS). With a new peak attributable to RGO at 261 nm appearing in UV–vis and XRD spectra of the reduced product also developed a new peak at 2θ = 24.6° characteristic of RGO. Successful reduction was also supported by Raman spectroscopy which showed that the ratio of the intensity band (D band: G band) increased from 0.99 to 1.17. FTIR and XPS both confirmed that specific O H (3399 cm−1), C O (1734 cm−1) and C O C (287 eV) bonds were reduced. Cyclic voltammograms (CVs) showed that the produced RGO exhibited good conductivity (changed from 0.8 to 1.1 mW·cm−2). This work developed a green and easy operated method of synthesizing RGO using microorganisms. [ABSTRACT FROM AUTHOR]

Organic solvent-tolerant proteases have many applications in the synthesis of peptides. In this study, we have developed a low-cost and convenient method to produce highly concentrated organic solvent-tolerant protease. Organic solvent tolerant protease (OSP) gene from Bacillus sphaericus DS11 was cloned and expressed in Bacillus subtilis WB800. The optimum pH of the recombinant protease was 9.0. The optimum temperature of the recombinant protease was 40 °C. The recombinant protease was purified by ethanol with the yield of (87.33%). The yield of OSP enriched by ethanol was higher than that of by Ni-chelating affinity chromatography, which indicated that precipitation of the recombinant OSP with ethanol is a relatively low-cost and fast method for organic solvent -tolerant protease preparation. These results showed that this enzyme could be very useful in different industrial applications. [ABSTRACT FROM AUTHOR]

• Bacillus Sphaericus possesses maximum urease activity and therefore, is suitable to be used for bacterial calcite precipitation in concrete. • Cement was replaced with MBS at various percentage levels. The strengths and durability characteristics were evaluated. • An improvement in strength and durability was observed with an optimum level of 8% MBS and 20 ml bacteria. • Through XRD analysis, it was observed that with MBS and bacteria, the intensity of peaks is higher. • The cracks were visualized for 3 days and 7 days which confirmed the healing of cracks due to the formation of calcite precipitate. The main idea of this study is to evaluate the mechanical and durability properties of high strength concrete specimens by incorporating an alternative for cement along with bacteria for healing cracks. The classic methods which are used for healing cracks involve the use of ordinary synthetic polymers which further cause a lot of damage to the environment. Therefore, the use of sustainable strategies like ingesting bacterial culture into the concrete mix along with an alternative replacement for cement can act as an active support for both nature as well as construction industries. In this paper, control concrete, concrete made by replacing cement with Micronized Biomass Silica (MBS) at 4%, 8% and 12% and bacteria induced concrete are compared. The bacteria used is Bacillus Sphaericus with optical density as 1.00 and is mixed in control as well as MBS made concrete specimens at different levels of 10 ml, 20 ml, 30 ml for each. With a total of 16 mix designs of characteristic compressive strength 60 N/mm2 at the age of 28 days curing (M60 grade) high strength concrete cubes, cylinders and beams are compared on grounds of compressive strength, splitting tensile, flexural strengths, water absorption and sorptivity. It was concluded that, specimens with 8% MBS and 20 ml bacteria showed optimum results based on strength and durability characteristics. Further, an artificial crack was induced in the specimen and the bacteria's healing activities along with calcite precipitation were examined through X-Ray diffraction, Scanning Electron Microscope (SEM) and visualization analysis. A high intensity of peaks was observed with MBS and bacteria and the cracks were visualized for 3 days and 7 days which ratified the healing of cracks due to the formation of calcite precipitate which was confirmed through SEM Analysis. [ABSTRACT FROM AUTHOR]

The microbial larvicides Bacillus thuringiensis var. israelensis (Bti) and Bacillus sphaericus (Bs) (Bacillales: Bacillaceae) are well known for their efficacy and safety in mosquito control. In order to assess their potential value in future mosquito control strategies in western Kenya, the current study tested the susceptibility of five populations of Anopheles gambiae complex mosquitoes (Diptera: Culicidae), collected from five diverse ecological sites in this area, to Bti and Bs under laboratory conditions. In each population, bioassays were conducted with eight concentrations of larvicide (Bti/Bs) in four replicates and were repeated on three separate days. Larval mortality was recorded at 24 h or 48 h after the application of larvicide and subjected to probit analysis. A total of 2400 An. gambiae complex larvae from each population were tested for their susceptibility to Bti and Bs. The mean (± standard error of the mean, SEM) lethal concentration values of Bti required to achieve 50% and 95% larval mortality (LC50 and LC95) across the five populations were 0.062  (± 0.005) mg/L and 0.797 (± 0.087) mg/L, respectively. Corresponding mean  (± SEM) values for Bs were 0.058 (± 0.005) mg/L and 0.451 (± 0.053) mg/L, respectively. Statistical analysis indicated that the five populations of An. gambiae complex mosquitoes tested were fully susceptible to Bti and Bs, and there was no significant variation in susceptibility among the tested populations. [ABSTRACT FROM AUTHOR]

Abstract Microbes play important roles in the transport and transformation of selenium (Se) in the environment, thereby influencing plant resistance to Se and Se accumulation in plant. The objectives are to characterize the bacteria with high Se tolerance and reduction capacity and explore the significance of microbial origins on their Se tolerance, reduction rate and efficiency. Two bacterial strains were isolated from a naturally occurred Se-rich soil at tea orchard in southern Anhui Province, China. The reduction kinetics of selenite was investigated and the reducing product was characterized using scanning electron microscopy and transmission electron microscopy-energy dispersive spectroscopy. The bacteria were identified as Lysinibacillus xylanilyticus and Lysinibacillus macrolides , respectively, using morphological, physiological and molecular methods. The results showed that the minimal inhibitory concentrations (MICs) of selenite for L. xylanilyticus and L. macrolides were 120 and 220 mmol/L, respectively, while MICs of selenate for L. xylanilyticus and L. macrolides were 800 and 700 mmol/L, respectively. Both strains aerobically reduced selenite with an initial concentration of 1.0 mmol/L to elemental Se nanoparticles (SeNPs) completely within 36 hr. Biogenic SeNPs were observed both inside and outside the cells suggesting either an intra- or extracellular reduction process. Our study implied that the microbes from Se-rich environments were more tolerant to Se and generally quicker and more efficient than those from Se-free habitats in the reduction of Se oxyanions. The bacterial strains with high Se reduction capacity and the biological synthesized SeNPs would have potential applications in agriculture, food, environment and medicine. Graphical abstract Unlabelled Image [ABSTRACT FROM AUTHOR]

Highlights • Alkaline protease was purified to homogeneity by a three-step strategy. • Enzymatic properties of the purified alkaline protease were investigated. • Kinetic constants of the purified alkaline protease were determined. Abstract Alkaline protease was purified from Bacillus sp. ZJ1502 isolated from fermented bean curd and its enzymatic properties were investigated. The final purification fold and specific activity were 18.6 and 30,230 U/mg, respectively. The molecular weight was 14 kDa by SDS-PAGE. The optimal pH and temperature were 10.0 and 40 °C, respectively. Alkaline protease showed high stability at pH 9–11. Mn2+ and Tween-80 improved its activity by 22% and 31%, respectively, while SDS, CMC and EDTA respectively inhibited its activity by 33%, 47% and 22%. Alkaline protease exhibited poor tolerance to n -butyl alcohol and ethanol, but showed resistance to H 2 O 2. 29.8% of the original activity was still retained after 0.5 M H 2 O 2 treatment for 3 min. The K m and V max values of this enzyme towards casein were 16.7 mg/ml and 14.7 µg/(min·ml), respectively. This study provides a basis for understanding enzymatic properties of Bacillus sp. ZJ1502 alkaline protease. [ABSTRACT FROM AUTHOR]

The purpose of this study is to isolate the beneficial microorganisms whose growth is promoted in the presence of charcoal materials. We successfully isolated strain IA, whose growth is promoted on an agar plate with charcoal materials, and identified it as a novel strain of the Bacillus sp. The growth of strain IA in the liquid medium was promoted by the addition of both activated charcoal (AC) and rice husk biochar (RHB). Moreover, the sporulation of strain IA in the RHB medium and the antifungal activity of the culture supernatant of the RHB medium were much higher than those with AC. HPLC and MS analyses revealed that strain IA produced an antifungal lipopeptide iturin A, and the yield of iturin A in the RHB medium was 8 times higher than that in the medium without RHB. This is the first paper to describe the positive effect of RHB on microbial metabolisms. © Pesticide Science Society of Japan. [ABSTRACT FROM AUTHOR]

Highlights • A novel mutant Bsp PVA-3 (T63S/N198Y/S110C) was produced by directed evolution. • The catalytic efficiency of mutant Bsp PVA-3 was greatly improved compared to the wild-type Bsp PVA. • Enhancement of specific activity of mutant Bsp PVA-3 was probably attributed to the changes in the number of hydrogen bonds within the molecules based on the analysis of modeling. • The conversion yield of 6-APA catalyzed by Bsp PVA-3 was significantly improved and the time of reaction was shortened compared to the wild-type Bsp PVA. Abstract Penicillin acylase is commonly used to produce the medical intermediates of 6-Aminopenicillanic acid (6-APA) and 7-Aminodesacetoxycephalosporanic acid (7-ADCA) in industrial process. Nowadays, Penicillin G acylase (PGA) has been widely applied for making pharmaceutical intermediates, while penicillin V acylase (PVA) has been less used for that due to its low activity and poor conversion. In this study, a PVA from Bacillus sphaericus (Bsp PVA) was employed for directed evolution study with hoping to increase its catalytic efficiency. Finally, a triple mutant Bsp PVA-3 (T63S/N198Y/S110C) was obtained with 12.4-fold specific activity and 11.3-fold catalytic efficiency higher than Bsp PVA-wt (wild type of Bsp PVA). Moreover, the conversion yields of 6-APA catalyzed by Bsp PVA-3 reached 98% with 20% (w/v) penicillin V as substrate, which was significantly higher than that of the Bsp PVA-wt (85%). Based on the analysis of modeling, the enhancement of specific activity of mutant Bsp PVA-3 was probably attributed to the changes in the number of hydrogen bonds within the molecules. The triple mutant PVA developed in this study has a potential for large-scale industrial application for 6-APA production. [ABSTRACT FROM AUTHOR]

Biodegradation of agribiomass especially wheat straw to biohydrogen and biomethane is an encouraging approach to the current waste management problem. To do so, the biomass must first be pretreated to break down lignin thereby increasing accessibility of the substrate to fermentative organisms. In the current study, out of 20 isolates from the granular sludge of full-scale anaerobic digester, four ligninolytic Bacillus sp. strains were selected based on their lignin and Azure B degradation. Further, among the four isolates, Brevibacillus agri AN-3 exhibited the highest of 88.4 and 78.1% decrease in COD of lignin and Azure B respectively. These strains were also found to secrete optimum yields of lignin peroxidase (LiP) at pH 3, laccase (Lac) at pH 5, and xylanase and cellulase enzymes at pH 7. The strains demonstrated maximum activity of Lip and Lac at 50 °C and xylanase and cellulase at 60 °C after 72-h growth. Among the four strains, Brevibacillus agri AN-3 showed hydrogen (H2) yield of 1.34 and 2.9 mol-H2/mol from xylose and cellulose respectively. In two-phase wheat straw batch fermentation, Brevibacillus agri AN-3 produced 88.3 and 283.7 mL/gVS cumulative H2 and methane (CH4) respectively. Biotreatment with ligninolytic Bacillus sp. strains perceived that 261.4% more methane yield could be obtained from the wheat straw than using the untreated wheat straw in batch fermentation. This is the first study establishing not only the hydrogen potential of ligninolytic Bacillus sp. strains but also indicates a vital role of these species in developing standard inoculum and a biocatalyst for processing agribiomass.ᅟ [ABSTRACT FROM AUTHOR]

Cellualse is one of the most important enzymes used in textile, detergent, paper, food and feed industries. Therefore, a study was undertaken to isolate Bacillus bacteria having the potential to produce cellulase from soil samples. 24 soil samples were analyzed and 54 presumptive Bacillus isolates were isolated after heating the soil samples at 80°C for 10 min. Among them 45 isolates showed enzyme activity ranging from 0.003 to 0.17 U/ml in test tubes containing 5 ml medium composed of (g/L) glucose 0.5 gm, peptone 0.75 gm, FeSO4 0.01 gm, KH2PO4 0.5 gm, and MgSO4 0.5 gm at 120 rpm, 37 °C and pH 7. Among them 1RW, 2WS, 3YR, 4WT, 6 RR, and 9SS showed 0.17, 0.15, 0.14, 0.15, 0.147 and 0.14U/ml enzyme activities, respectively. Production of cellulase by these isolates was further scaled up to shake culture containing 50 ml medium similar to that used in test tube culture. Among the isolates 1 RW showed the maximum activity. This 1 RW was identified by API kit and showed that 59 % belongs to Bacillus licheniformis strain (51% confirmation) or Bacillus subtilis (31% confirmation). Further gene analysis is required to confirm the species. The genetic improvement study will make the isolate a good source of cellulase. [ABSTRACT FROM AUTHOR]

This work aimed to develop green biodegradable film using red seaweed ( Kappaphycus alvarezii ) as a base matrix and calcium carbonate (CaCO 3 ) as a filler to enhance the properties of the red seaweed material for plasticulture purpose. CaCO 3 which was produced by microbially induced precipitation (MB-CaCO 3 ) using Bacillus sphaericus , was characterized and compared with the commercial CaCO 3 (C CaCO 3 ). FESEM image revealed that the size of MB-CaCO 3 was smaller and more uniform compared to C CaCO 3 . FTIR and XRD analyses confirmed the existence of crystalline polymorph of calcite in MB-CaCO 3 , which contained a higher percentage of calcite than C CaCO 3 . However, the crystallinity and thermal stability of MB-CaCO 3 was lower than C CaCO 3 . From the results of physical, mechanical and thermal properties of composite films filled with C CaCO 3 and MB-CaCO 3 fillers, the optimum loading of C CaCO 3 and MB-CaCO 3 was found at 0.1% and 0.15%, respectively. Composite films filled with MB-CaCO 3 promote brighter film, better water barrier, hydrophobicity and biodegradability compared to C CaCO 3 . Since the effect of MB-CaCO 3 on film functional properties was comparable to C CaCO 3 , it can be used as an alternative to C CaCO 3 as inorganic filler for composite films in agriculture applications. [ABSTRACT FROM AUTHOR]

Abstract: Aim: The aim of this study was to isolate and identify lipolytic bacteria. Perform a statistical stepwise physicochemical optimization for maximum production of extracellular lipase and its validation in a bioreactor. Methods and Results: Several lipolytic bacteria were isolated from petroleum hydrocarbon‐polluted soil. The strain expressing the highest lipase activity (47 U ml−1) was genetically identified as Gram‐positive Bacillus stratosphericus PSP8 (NCBI GenBank accession no. MH120423). The response surface methodology (RSM)–central composite face centre (CCF) design of experiments was performed based on the preselected levels of the studied parameters obtained from the performed one‐factor‐at‐a‐time sequential experiments. A second‐order polynomial model was predicted and improved the lipase production by approximately 1·6‐fold. Preliminary scaling up of the validated optimized process was carried out in a batch 10‐l stirred tank bioreactor, applying the optimum predicted operating conditions; pH 6·98, 34·8°C, 2·2 × 106 cells per ml, 200 rev min−1, 4·82 g l−1 tributyrine concentration, 1% sucrose and 0·1% yeast extract. This yielded 89 U ml−1 at the late log phase of bacterial growth (48 h). Logistic kinetic model effectively characterized the submerged fermentation process, and the maximum specific growth and lipase production rates were estimated to be 0·338 and 0·164 h−1 respectively. Conclusions: The mesophilic and neutrophilic B. stratosphericus PSP8 isolated from petroleum hydrocarbon‐contaminated soil is a proper source of lipase. The closeness of the predicted response with that of the experimental value and the enhancement of lipase productivity in fermenter scale by approximately 1·9‐fold, showed that statistically optimized design can be used in order to improve the lipase production to meet the increasing demand. Significance and Impact of the Study: The RSM‐CCF statistical optimization is useful for optimizing a large number of variables and studying their interactive effects on extracellular lipase production. [ABSTRACT FROM AUTHOR]

Bacillus sp. SJ-10 (KCCM 90078, JCM 15709) is a halotolerant bacterium isolated from a traditional Korean food, i.e., salt-fermented fish (jeotgal). The bacterium can survive and engage in metabolism at high salt concentrations. Here, we reported complete genome sequence of Bacillus sp. SJ-10, which has a single circular chromosome of 4,041,649 base pairs with a guanine-cytosine content of 46.39%. Bacillus sp. SJ-10 encodes a subunit of poly-γ-glutamic acid (γ-PGA) with a molecular weight of approximately 400 kDa, which contains four γ-PGA synthases (pgsB, pgsC, pgsAA and pgsE) and one γ-PGA-releasing gene (pgsS). This bacterium also able to produce salt-stable enzymes such as protease, β-glucosidase, and β-1,3-1,4-glucanase. This affords significant insights into strategies employed by halotolerant bacteria to survive at high salt concentrations. The sequence contains information on secondary metabolites biosynthetic gene cluster, and most importantly enzymes produced by the bacterium may be valuable with respect to food, beverage, detergent, animal feed, and certain commercial contexts. [ABSTRACT FROM AUTHOR]

Aerobic spore-forming bacteria, mainly Bacillus spp., are of real concern to dairy industries due to their ability to produce hydrolytic extracellular enzymes causing off-flavours and structural defects in pasteurised milk. In this study, bacteria were isolated and characterised from Maltese raw and pasteurised cows’ milk samples, with sample collection carried out in both summer and winter seasons. Winter and summer raw milk samples had similar bacterial count, while winter pasteurised milk samples showed a higher level of surviving bacteria than summer pasteurised milk samples. The 16S r RNA sequencing performed on isolates from pasteurised milk showed aerobic spore-forming bacteria (e.g., Bacillus cereus ) and a wide range of non-spore forming bacteria were identified including; coryneforms, Enterococcus spp., Streptococcus sp. Growth kinetic studies using B. cereus indicated that the minimum temperature for growth ( T min ), and the maximum cardinal temperatures ( T max ) of the isolated B. cereus were 6.38 °C and 44.23 °C, respectively. [ABSTRACT FROM AUTHOR]

Lysinibacillus sphaericus C3-41 carries a large low-copy-number plasmid pBsph, which encodes binary toxin proteins. Our previous study found that the transcriptional activator TubX plays an important role in the newly identified type Ⅲ TubRZC replication/partition system in pBsph, and that a vector consisting of tubRZC and tubX is not as stable as pBsph, indicating the presence of other maintenance module(s). In this study, we identified that orf9 and orf10 are necessary for the stability of pBsph by a series of deletion and complementation experiments. Bioinformatics analysis showed that ORF9 contains a PIN domain of VapBC toxin-antitoxin (TA) system, whereas ORF10 share no significant sequence similarity to any of the characterized antitoxins in the database. Further studies revealed that orf9 and orf10 are transcribed as an operon. The overexpression of ORF9 repressed the growth of both Escherichia coli and L. sphaericus , which can be alleviated by overexpression of ORF10. The deletion of orf10 individually or orf9-10 together resulted a decrease on plasmid stability which was restored by the complementation of corresponding gene(s), suggesting that ORF10 plays an important role in plasmid stability. In addition, it was found the plasmid stability is related with the transcription level of tubRZ, and overexpression of TubRZ could neutralize the negative effect on plasmid stability caused by the deletion of orf9-orf10 . Moreover, the recombinant vector containing tubRZC , tubX and orf9-10 was more stable than the ones containing only tubRZC and either tubX or orf9-10. The data indicate that the plasmid maintenance system on pBsph includes orf9-orf10 TA system. [ABSTRACT FROM AUTHOR]

βγ-crystallin has emerged as a superfamily of structurally homologous proteins with representatives across all domains of life. A major portion of this superfamily is constituted by microbial members. This superfamily has also been recognized as a novel group of Ca2+-binding proteins with a large diversity and variable properties in Ca2+ binding and stability. We have recently described a new phosphatidylinositol phospholipase C from Lysinibacillus sphaericus (LS-PIPLC) which was shown to efficiently remove phosphatidylinositol from crude vegetable oil. Here, the role of the C-terminal βγ-crystallin domain of LS-PIPLC was analyzed in the context of the whole protein. A truncated protein in which the C-terminal βγ-crystallin domain was deleted (LS-PIPLCΔCRY) is catalytically as efficient as the full-length protein (LS-PIPLC). However, the thermal and chemical stability of LS-PIPLCΔCRY are highly affected, demonstrating a stabilizing role for this domain. It is also shown that the presence of Ca2+ increases the thermal and chemical stability of the protein both in aqueous media and in oil, making LS-PIPLC an excellent candidate for use in industrial soybean oil degumming. [ABSTRACT FROM AUTHOR]

Abstract: The microbial larvicides Bacillus thuringiensis var. israelensis and Bacillus sphaericus have been used extensively for mosquito control and have been found to be effective and safe to non‐target organisms cohabiting with mosquito larvae. Recently developed long lasting microbial larvicides (LLML), although evading the previous challenge of short duration of activity, increase the risk of persistence of toxins in the treated larval habitats. This study monitored the impact of LLML FourStar® and LL3 on non‐target organisms cohabiting with mosquito larvae in an operational study to control malaria vectors in western Kenya highlands. A total of 300 larval habitats were selected in three highland villages. The habitats were first monitored for 5 weeks to collect baseline data on non‐target organisms cohabiting with mosquito larvae and then randomized into two treatment arms (respective FourStar® and LL3) and one control arm. Non‐target organisms were sampled weekly for 5 months after treatment to assess the impact of LLML intervention. Before treatment, the mean density of all non‐target organisms combined in the control, LL3 and FourStar® treated habitats was 1.42, 1.39 and 1.49 individuals per habitat per sampling occasion, respectively. Following treatment, this density remained fairly unchanged for 21 weeks at which time it was 1.82, 2.11, and 2.05 for the respective control, LL3 and FourStar® treated habitats. Statistical analysis revealed that LL3 and FourStar® did not significantly alter abundance, richness or diversity of the 11 taxa studied, when comparing the intervention and control larval habitats. However, both FourStar® and LL3 significantly reduced the density of malaria vectors. In conclusion, one round of label rate application of FourStar® or LL3 in natural larval habitats did not alter richness, abundance or diversity of the monitored aquatic non‐target organisms cohabiting with mosquito larvae to an ecologically significant level. [ABSTRACT FROM AUTHOR]

Abstract In the current study, the biocontrol potential of a novel strain Bacillus sp. PPM3 isolated from marine sediment from the Red Sea in Hurghada, Egypt is recognized. This novel strain was selected out of 32 isolates based on its ability to suppress the growth of four plant pathogenic fungi: Aspergillus flavus, Fusarium graminearum, Mucor sp. and Alternaria sp. The new marine strain was identified and characterized by phenotypic and molecular approaches. The culture filtrate of Bacillus sp. PPM3 suppressed the growth and spore germination of all tested fungi in vitro with the highest value of inhibition reported for Mucor sp. (97.5%). The antifungal effect of the culture filtrate from the strain PPM3 was due to production of highly stable secondary metabolites resistant to extreme pH, temperature and enzymatic treatments. A PCR analysis confirmed the expression of genes involved in the synthesis of antifungal lipopeptides: iturin, bacillomycin D, mycosubtilin and surfactin. In a greenhouse experiment strain PPM3 effectively reduced disease incidence of F. graminearum in maize plants and displayed additional plant growth stimulating effect. The results show that novel marine strain PPM3 could have a potential in commercial application as biocontrol agent for treatment of various plant diseases caused by soil-borne and postharvest pathogenic fungi. Highlights • Antifungal activity of a novel marine strain Bacillus sp. PPM3 was recognized. • PCR analysis confirmed presence of four antifungal genes in Bacillus sp. PPM3. • In greenhouse conditions, strain PPM3 reduced disease incidence in maize seedlings. • Treatment with Bacillus sp. strain PPM3 stimulated the growth of maize seedlings. [ABSTRACT FROM AUTHOR]

Antimicrobial peptides (AMPs) constitute a major arm of defense in mosquitoes against microbes. The purpose of this study was to determine which of the peptides are produced in the mosquito hemolymph after bacterial treatment. Culex pipiens (Diptera: Culicidae) larvae, collected from drainage canal in Suez Governorate, Egypt, were treated with LC80 of Bacillus sphaericus strain 2362 (0.035 ppm). The hemolymph of bacteria-treated Cx. pipiens mosquitoes and non-treated mosquitoes as control were extracted and undergo electrophoresis, using a Bio-Rad Mini-protean II cell. In Cx. pipiens mosquitoes emerging from bacteria-treated larvae, a band of protein was detected at 165 kDa. This protein was more likely to be Thioester-containing protein 1 (TEP1). Understanding mosquito resistance mechanism to bacterial control is crucial to build up programs to overcome such resistance. [ABSTRACT FROM AUTHOR]

The ultrastructure alterations were described in the midgut of Culex pipiens (Diptera: Culicidae) larvae following Bacillus sphaericus treatment. Two hours post-treatment, the epithelial layer began to have large amount of vacuoles. Explosion in the basement membrane took place 6 h post-treatment. Ten hours post-treatment, the bacterium began to invade the microvilli. At 14 h post-bacterial treatment, epithelial cells were destroyed, microvilli were damaged, and bacteria were present in lumen in large amount. The present study provided the evidence on the main aberrations induced in midgut larvae of Cx. pipiens as a result of ingesting B. sphaericus. [ABSTRACT FROM AUTHOR]

Mosquitoes are the most critical group of insects in the context of public health, since they transmit key parasites and pathogens, causing millions of deaths annually. Insecticides from natural products may boost the effectiveness of vector control programs. In this study, we tested silver nanoparticles (AgNPs) fabricated using the leaf extract of the orchid Zeuxine gracilis as reducing agent, and the microbial pesticide Bacillus sphaericus, against the mosquitoes Anopheles stephensi, Aedes aegypti and Culex quinquefasciatus. The synthesis of AgNP was confirmed analyzing the excitation of surface Plasmon resonance using ultraviolet–visible (UV–Vis) spectrophotometry. SEM and TEM showed the irregular shapes of AgNPs. EDX spectroscopy, FTIR spectroscopy, X-ray diffraction and dynamic light scattering analysis were carried out. AgNPs were highly effective against the larvae of An. stephensi (LC50 = 8.48 µg/mL), Ae. aegypti (LC50 = 10.39 µg/mL) and Cx. quinquefasciatus (LC50 = 13.21 µg/mL), respectively. Combined treatments testing B. sphaericus with AgNPs were also effective against An. stephensi (LC50 = 12.32 µg/mL), Ae. aegypti (LC50 = 14.78 µg/mL) and Cx. quinquefasciatus (LC50 = 19.19 µg/mL). Overall, this study suggests that the orchid-synthesized AgNPs can be a rapid, environmentally safer bio-pesticide to be used in synergy with B. sphaericus to control mosquito vectors. [ABSTRACT FROM AUTHOR]

Bacillus sp. N16-5 is an alkaliphile with a great ability to utilize mannan. Its mannan utilization gene cluster has been identified in a previous study. The ManR protein encoded by the cluster was predicted to be a LacI family regulator, and the transcription level of the mannan utilization gene cluster was upregulated after the manR gene was deleted, indicating that ManR is the repressor of this cluster. The transcription of the related genes was downregulated when manH, encoding the extracellular substrate-binding domain of the manno-oligosaccharide transporter, was deleted. Furthermore, isothermal titration calorimetry revealed that mannotetraose and mannopentose are ligands of ManR. These results all corroborate the hypothesis that the mannan utilization gene cluster is repressed by the transcription regulator ManR, and that the repression is removed when it binds to manno-oligosaccharides, which are generated by mannan degradation and transported into the cell by a specific transporter. [ABSTRACT FROM AUTHOR]

A total of 97 amino acids, considered as the signal peptide and transmembrane segments were removed from 205y lipase gene using polymerase chain reaction technique that abolished the low activity of this enzyme. The mature enzyme was expressed in Escherichia coli using pBAD expression vector, which gave up to a 13-fold increase in lipase activity. The mature 205y lipase (without signal peptide and transmembrane; −SP/TM) was purified to homogeneity using the isoelectric focusing technique with 53% recovery. Removing of the signal peptide and transmembrane segments had resulted in the shift of optimal pH, an increase in optimal temperature and tolerance towards more water-miscible organic solvents as compared to the characteristics of open reading frame (ORF) of 205y lipase. Also, in the presence of 1 mM inhibitors, less decrease in the activity of mature 205y lipase was observed compared to the ORF of the enzyme. Protein structure modeling showed that 205y lipase consisted of an α/β hydrolase fold without lid domain. However, the transmembrane segment could effect on the enzyme activity by covering the active site or aggregation the protein. [ABSTRACT FROM AUTHOR]

Biofertilizers are usually carrier-based inoculants containing beneficial microorganisms. Incorporation of microorganisms in carrier material enables easy-handling, long-term storage and high effectiveness of biofertilizers. Objective of the present study was to assess enriched biogas sludge and soil as biofertilizer carriers on growth and yield of wheat. Six phosphate solubilizing strains were used in this study. Three phosphate solubilizing strains, 77-NS2 ( Bacillus endophyticus ), 77-CS-S1 ( Bacillus sphaericus ) and 77-NS5 ( Enterobacter aerogenes ) were isolated from the rhizosphere of sugarcane, two strains, PSB5 ( Bacillus safensis ) and PSB12 ( Bacillus megaterium ) from the rhizosphere of wheat and one halophilic phosphate solubilizing strain AT2RP3 ( Virgibacillus sp.) from the rhizosphere of Atriplex amnicola, were used as bioinoculants. Phosphate solubilization ability of these strains was checked in vitro in Pikovskaya medium, containing rock phosphate (RP) as insoluble P source, individually supplemented with three different carbon sources, i.e., glucose, sucrose and maltose. Maximum phosphate solubilization; 305.6 μg/ml, 217.2 μg/ml and 148.1 μg/ml was observed in Bacillus strain PSB12 in Pikovskaya medium containing sucrose, maltose and glucose respectively. A field experiment and pot experiments in climate control room were conducted to study the effects of biogas sludge and enriched soil based phosphorous biofertilizers on growth of wheat. Bacillus strain PSB12 significantly increased root and shoot dry weights and lengths using biogas sludge as carrier material in climate control room experiments. While in field conditions, significant increase in root and shoot dry weights, lengths and seed weights was seen by PSB12 and PSB5 (Bacillus ) and Enterobacter strain 77-NS5 using biogas sludge as carrier. PSB12 also significantly increased both root and shoot dry weights and lengths in field conditions when used as enriched soil based inoculum. These results indicated that bacterial isolates having plant beneficial traits such as P solubilization are more promising candidates as biofertilizer when used with carrier materials. [ABSTRACT FROM AUTHOR]

Coral mucus is one of the key localization in the coral holobiont, as this serves as an energy rich substrate for a wide range of abundant, diverse and multifunctional microbiota. However, very little is known about the functional role of bacterial communities in their associations with corals. In the present study, a total of 48 isolates were obtained from Porites lutea wherein the genus of Bacillus sp. and Vibrio sp. were predominant. Bio-prospecting the coral mucus revealed the existence of (10.42%) antagonistic bacteria against the tested bacterial pathogens. Molecular taxonomy (16S rRNA) proved the identity of these antagonistic bacteria belong to Enterobacter cloacae (CM1), Bacillus subtilis (CM2), Bacillus sp. (CM11) and Bacillus marisflavi (CM12). The secondary screening emphasized that the ethyl acetate extract of B. subtilis showed strong antagonistic effect, followed by the chloroform extract of E. cloacae and ethyl acetate extract of B. marisflavi . The antagonistic activity was statistically confirmed by Principal Component Analysis and Hierarchical Cluster Analysis. The privileged coral mucus associated bacterial (CMAB) solvent extracts inhibited the bacterial pathogens at 100 μg/ml (MIC) and ceased the growth at 200 μg/ml (MBC). The hemolytic and brine shrimp lethality assays disclosed the non-toxic nature of solvent extracts of CMAB. Altogether, the present investigation brought out the diversity of bacteria associated with the mucus of P. lutea . In addition, bio-prospecting corroborated the CMAB as the potential source of pharmacologically important bioactive compounds against a wide range of bacterial pathogens. [ABSTRACT FROM AUTHOR]

This research focuses on improving the quality of mixed and ceramic recycled aggregates by microbially induced carbonate precipitation ( Bacillus sphaericus ). The precipitation contributed to a weight increase and unleashed a waterproofing response. The roughness of the ceramic particles created a more uniform layer compared to natural or concrete particles. For the concrete fraction, which had a higher macroporosity, the consolidation effect was more pronounced. High ceramic content aggregates profited from a greater biodeposition, leading to a remaining amount of precipitates after sonication which was still greater than in cementitious materials. Pore-filling effect was detected by SEM, supporting the waterproofing result. [ABSTRACT FROM AUTHOR]

Objective: The bio-efficacy of Tephrosia purpurea leaf extract and bacterial insecticide, Bacillus sphaericus larvicidal activity was assessed against the first to fourth instars larvae of Aedes aegypti, under the laboratory conditions. Methods: The plant material was shade dried at room temperature and powdered coarsely. T. purpurea and B. sphaericus show the various concentrations of larvicidal and pupicidal activity against various instars larvae of A. aegypti. Results: The LC50 of T. purpurea against the first to fourth instars larvae were 139.24, 176.24, 219.28, 256.27 and 326.29 ppm and the 480.72, 541.21, 580.34, 672.20, and 762.80 ppm, respectively. B. sphaericus against the first to fourth instars larvae the LC50 values were 46.16, 56.23, 69.82, 80.81 and 96.12 ppm and the LC90 values 141.68, 172.46, 184.21, 193.31 and 218.16 ppm, respectively. However, the combined treatment of T. purpurea + B. sphaericus (1:2) material shows highest larvicidal activity of the LC50 values 80.08, 82.21, 88.00, 92.21 and 98.16 ppm; The LC90 values of 108.39, 118.71, 136.75, 149.02 and 153.24 ppm, against A. aegypti in all the tested concentrations than the individuals and clearly established that there is a substantial amount of synergist act. Conclusion: The present study reported that both T. purpurea and B. sphaericus materials could serve as a potential larvicidal agent. Since, A. aegypti is a container breeder vector mosquito this user and eco-friendly and low-cost vector control strategy could be a viable solution to the existing dengue disease burden. Therefore, this study provides first report on the mosquito larvicidal activity the combined effect of T. purpurea leaf extract and B. sphaericus against as target species of A. aegypti. [ABSTRACT FROM AUTHOR]

Bacillus sphaericus is a biopesticide that is highly effective for the control of mosquitos under harsh conditions such as polluted areas and UV light. In addition to its bioactivity, it produces proteases. In this present study, the composition of media comprising corn steep liquor (CSL) and molasses was optimised using response surface methodology (RSM) with a central composite design (CCD). Four different scenarios were arranged involving sole biopesticide and protease optimization (Scenarios 1 and 2), biopesticide optimization with protease as a by-product (Scenario 3) and protease optimization with biopesticide as a by-product (Scenario 4). The optimization of the simultaneous production of biopesticide and protease was not satisfactory to obtain large amounts of both products; however, when the production aim was a sole production with a by-product, optimal working conditions could be achieved. Also, according to industrial view, Scenario 1 is the only possible process for large scale systems. [ABSTRACT FROM AUTHOR]

Although Membrane Distillation (MD) has been extensively studied for desalination, it has other applications like removing all kinds of solutes from water and concentrating non-volatile substances. MD offers the possibility of producing a clean stream while concentrating valuable compounds from waste streams towards their recovery, or emerging contaminants and pathogens present in wastewater in order to facilitate their chemical elimination. This paper analyses the elimination of bacterial spores from contaminated water with MD and the role of MD in the subsequent treatment of the concentrate with photo-Fenton process. The experiments were performed at Plataforma Solar de Almería (PSA) using a plate and frame bench module with a Permeate Gap Membrane Distillation (PGMD) configuration. Tests were done for two different kinds of spores in two different water matrixes: distilled water with 3.5 wt% of sea salts contaminated with spores of Bacillus subtilis ( B. subtilis ) and wastewater after a secondary treatment and still contaminated with Clostridium sp. spores. An analysis of the permeate was performed in all cases to determine its purity, as well as the concentrated stream and its further treatment in order to assess the benefits of using MD. Results showed a permeate free of spores in all the cases, demonstrating the viability of MD to treat biological contaminated wastewater for further use in agriculture. Moreover, the results obtained after treating the concentrate with photo-Fenton showed a shorter treatment time for the reduction of the spore concentration in the water than that when only photo-Fenton was used. [ABSTRACT FROM AUTHOR]

The role of Culex pipiens larval ingestion rate in the effectiveness of three Bacillus sphaericus strains, namely 2362, B1-634BNI and 6491 was assessed. Two concentrations, namely LC50 and LC80, were tested. Studied parameters included bacterial exposure time and mosquito larval density. Exposure time periods were 0.5, 1, 2, 4, and 24 h. Larval density varied by exposing different numbers of larvae yielding larval density of 0.1, 0.2, 0.4, 0.8 and 1.6 larva/ml. Larval density also varied by exposing 20 larvae in different water volumes yielding larval density of 0.8, 0.4, 0.2 and 0.1 larva/ml. Strain B1-634BNI was the most active (LC50 = 0.02 ppm) among the tested strains. Mortality rates of larvae varied at different exposure periods and with the different larval densities. Mortality rates of Cx. pipiens larvae increased with the increase of the exposure period of the larvae to the bacterial suspension of strain B1-634BNI either at its LC50 or LC80. As larval density increased, mortality rates of larvae decreased when treated with each of the three tested bacterial strains whether at its LC50 or LC80. Adjusting bacterial application in control programmes according to those elements is thus indispensable to ensure a satisfactory result. [ABSTRACT FROM AUTHOR]

The suitability of using a spore-forming ureolytic strain, Bacillus sphaericus, was evaluated for self-healing of concrete cracks. The main focus was on alkaline tolerance, calcium tolerance, oxygen dependence, and low-temperature adaptability. Experimental results show that B. sphaericus had a good tolerance. It can grow and germinate in a broad range of alkaline pH. The optimal pH range is 7 ∼ 9. High alkaline conditions (pH 10 ∼ 11) slow down but not stop the growth and germination. Oxygen was strictly needed during bacterial growth and germination, but not an essential factor during bacterial urea decomposition. B. sphaericus also had a good Ca tolerance, especially at a high bacterial concentration of 10 cells/mL; no significant influence was observed on bacterial ureolytic activity of the presence of 0.9M Ca. Furthermore, at a low temperature (10 °C), bacterial spores germinated and revived ureolytic activity with some retardation. However, this retardation can be counteracted by using a higher bacterial concentration and by supplementing yeast extract. It can be concluded that B. sphaericus is a suitable bacterium for application in bacteria-based self-healing concrete. [ABSTRACT FROM AUTHOR]

Diaphorases are flavin-containing enzymes with potential applications in biotransfomation reactions, biosensor design and in vitro diagnostic tests. In this communication, we describe recombinant expression, characterization and application of a lipoamide dehydrogenase (DLD) with diaphorase activity from a strain of Bacillus sphaericus. The DLD gene consisting of 1413 bp encoding a protein of 470 amino acids was expressed in Escherichia coli BL21 (DE3) and the recombinant enzyme was characterized. B. sphaericus DLD catalyzed the reduction of NAD by dihydrolipoamide and exhibited NADH-dependent diaphorase activity. The molecular weight of purified enzyme was about 50 kDa, and determined to be a monomeric protein. Diaphorase was active and stable from pH 7.0 to 9.0 with an optimal activity at pH 8.5. It showed its maximal activity at temperature of 30 °C and was almost stable at temperatures between 25 and 30 °C. Different metal ions and inhibitors showed no influence on the activity of target enzyme. The K and V values for NADH were estimated to be 0.33 mM and 200.0 U/ml, respectively. Moreover, recombinant B. sphaericus diaphorase exhibited considerable potential to be used as a component of diagnostic tests for the quantification of metabolites. In conclusion, considering the properties of diaphorase from B. sphaericus PAD-91, it can have potential application as a diagnostic enzyme. [ABSTRACT FROM AUTHOR]

Mosquitoes are important vectors of many infectious diseases. Bacillus sphaericus (Bs) is an ideal larvicide and has attracted more and more attention, recently. However, the fundamental research of its application is very limited, especially on the subsequent impact of Bs exposure on mosquito's fecundity and resistance emergence. Through bioassay, LC50 and LC95 of Bs in killing Anopheles dirus larvae were determined as 9.793 ± 1.878 IU/L and 62.4 ± 6.438 IU/L at 48 h posttreatment, 7.128 ± 0.913 IU/L and 34.385 ± 12.547 IU/L at 72 h post treatment, respectively. After being treated with a sub-lethal dose of Bs, gravidity, oviposition, hatch, pupation, and eclosion of the surviving mosquitoes were counted and analyzed to elucidate the subsequent effects of Bs exposure on the reproductive capacity of A. dirus. The result interestingly showed that the exposure of Bs significantly reduced the oviposition ability of the surviving A. dirus, without effect on egg formation/gravidity, hatch, pupation, and eclosion. The surviving mosquitoes were also maintained routinely for generations to test the sustained effect of Bs exposure on the fecundity of the offsprings. After conventional breeding for generations, the capacity of egg laying totally recovered. To explore the rules of resistance development, bioassays were performed after treatment twice with a sub-lethal dose of Bs on two continuous generations of A. dirus larvae. The killing efficacies between the Bs treated group and control group were compared. The results showed that LC50 and LC95 increased by 4.35- and 7.37-folds after treatment with the sub-lethal dose of Bs on two consecutive generations, respectively. The results indicated that A. dirus was sensitive to Bs, which could reduce oviposition of the surviving A. dirus. The subsequent effect might help to further decrease the mosquito population. However, a sub-lethal dose of Bs exposure could easily cause resistance development. Our study provides a dose standard and reference for the rational use of Bs, which will be helpful for mosquito control. [ABSTRACT FROM AUTHOR]

• Alkali activated lightweight aggregate generated from fly ash and Sidoarjo volcanic mud (Lusi). • The mechanical properties, healing and sealing performance of resulting mortar were investigated. • The vegetative cells of Bacillus sphaericus was employed as healing agent. • Fly ash based LWA provided comparable healing and sealing performance as a commercial expanded clay carrier. • The fly ash-based LWA provided excellent autogenous healing in young mortar. A bacteria-based self-healing concrete has been proposed for the autonomous repair of micro-cracks. However, the bacteria need protection to survive in concrete until cracks would appear. Here, vegetative cells of Bacillus sphaericus have been encapsulated into novel alkali activated lightweight aggregate (LWA) generated from fly ash and Sidoarjo volcanic Mud (Lusi). For the production of self-healing mortar, 30% by volume of the fine aggregates were replaced by bacteria impregnated LWA. The mechanical properties of the resulting mortar, the healing performance, sealing efficiency and healing product morphology were investigated. The results show that with vegetative cells as healing agent, a significant decrease in healing performance was observed when cracks were fabricated at later age. Furthermore, fly ash based LWA provided comparable healing and sealing performance as a commercial expanded clay carrier used for comparison. In addition, the fly ash-based LWA carrier provided excellent autogenous healing in young mortar. [ABSTRACT FROM AUTHOR]

Background: Outdoor malaria transmission is becoming an increasingly important problem in malaria control in Africa. Larval control is a promising intervention as it can target both indoor and outdoor biting mosquitoes. However, the currently available biolarvicide formulations have a short effective duration, and consequently larval control incurs a high operational expense due to the requirement for frequent re-treatment of larval habitats. Formulations of biolarvicides with long-lasting effects is highly desired. A recently developed FourStar® slow-release briquet formulation of Bacillus thuringiensis israelensis and Bacillus sphaericus was evaluated to test its efficacy on malaria vectors. Methods: The study evaluated FourStarTM briquets 180-days formulation under semi-natural and natural conditions to test their efficacy in reducing the mosquito population in western Kenya. The semi-natural habitats used the formulation dissolved in rainwater with appropriate concentrations, and second-instar larvae of Anopheles gambiae were introduced and the number of surviving larvae and pupae produced was recorded daily as the outcome. The briquets formulation was then tested in natural habitats for efficacy on pupal productivity reduction in highland and lowland sites in western Kenya. The formulation was finally tested for efficacy in reducing adult mosquito populations in randomized clusters in western Kenya highland. Results: In semi-natural conditions, the FourStarTM briquets 180-days formulation completely inhibited mosquito pupal production in the first 3 months, and then reduced pupal productivity by 87-98% (P < 0.001) 4-6 months after application. In natural habitats, during the first 2 months no pupae were detected from any of the treated habitats in highland sites, and Anopheles spp. pupal density was reduced by 60-90% in the next 3-5 months (P < 0.001). In the lowland site, pupal productivity reduction was 100% in the first 3 months, and 75-90% in the next 4-5 months (P < 0.001). The randomized cluster trial found that the application of the briquets formulation reduced mean densities of indoor-biting mosquitoes by 76-82% (P < 0.001) and by 67-75% (P < 0.001) for outdoor-biting mosquitoes. Conclusion: This study demonstrated that long-lasting biological larviciding was effective in reducing pupal productivity of larval habitats, and reducing indoor and outdoor resting mosquitoes. The study suggests that long-lasting microbial larviciding may be a promising complementary malaria vector control tool and warrants further large-scale evaluation. [ABSTRACT FROM AUTHOR]

Bacillus sp. MFD11 (JF901809) and Enterobacter sp.SEL2 (JF901810) were isolated from agriculture waste contaminated sites. When fed with 2% glucose as a carbon source, these bacteria produced 75.26±0.45% and 76.61±0.28% PHA of their wet weight respectively. The accumulated PHA was extracted by direct addition of sodium dodysyl sulphate in the culture medium, which yielded 52.3±0.56 μg/l and 136.21±0.45 μg/l PHA respectively when assayed with Crotonic acid. The PHA detection medium (PDM) provided nutrient limitation condition which favored accumulation of PHA granules. A tremendous increase in cell size was observed when strain MFD11 was grown in PDM. The size of the granules as revealed by TEM micrographs spanned from 0.1 to 1.5μm which is quite large as compared to the size reported in the literature 0.2 to 0.5μm 18]. [PHA polymer was analyzed by FTIR, GC/MS and proton Nuclear magnetic resonance. The intense absorption band in the spectrum at 1724-1740 cm -1 and 1215 cm -1 to 1280 corresponding to C=O and C-O stretching group, respectively, indicated that the both strains were PHA producers. GC/MS analysis indicated that the polymer produced were copolymers of PHB-co-PHV. NMR also suggested that the extracted PHA was not a homopolymer but was the blend of copolymers with 3HV in lower abundance. Differential calorimetric thermal analysis showed melting temperature of 163 and 169 °C for PHA produced by both strains, respectively. However, the observed melting temperature was found to be lower than the standard PHB (Sigma-Aldrich). [ABSTRACT FROM AUTHOR]

Background: There is a global need for cost-effective and environmentally friendly tools for control of mosquitoes and mosquito-borne diseases. One potential way to achieve this is to combine already available tools to gain synergistic effects to reduce vector mosquito populations. Another possible way to improve mosquito control is to extend the active period of a given control agent, enabling less frequent applications and consequently, more efficient and longer lasting vector population suppression. Methodology/principal findings: We investigated the potential of biodegradable wax emulsions to improve the performance of semiochemical attractants for gravid female culicine vectors of disease, as well as to achieve more effective control of their aquatic larval offspring. As an attractant for gravid females, we selected acetoxy hexadecanolide (AHD), the Culex oviposition pheromone. As toxicant for mosquito larvae, we chose the biological larvicides Bacillus thuringiensis israelensis (Bti) and Bacillus sphaericus (Bs). These attractant and larvicidal agents were incorporated, separately and in combination, into a biodegradable wax emulsion, a commercially available product called SPLAT (Specialized Pheromone & Lure Application Technology) and SPLATbac, which contains 8.33% Bti and 8.33% Bs. Wax emulsions were applied to water surfaces as buoyant pellets of 20 mg each. Dose-mortality analyses of Culex quinquefasciatus Say larvae demonstrated that a single 20 mg pellet of a 10−1 dilution of SPLATbac in a larval tray containing 1 L of water caused 100% mortality of neonate (1st instar) larvae for at least five weeks after application. Mortality of 3rd instar larvae remained equally high with SPLATbac dilutions down to 10−2 for over two weeks post application. Subsequently, AHD was added to SPLAT (emulsion only, without Bs or Bti) to attract gravid females (SPLATahd), or together with biological larvicides to attract ovipositing females and kill emerging larvae (SPLATbacAHD, 10−1 dilution) in both laboratory and semi-field settings. The formulations containing AHD, irrespective of presence of larvicides, were strongly preferred as an oviposition substrate by gravid female mosquitoes over controls for more than two weeks post application. Experiments conducted under semi-field settings (large screened greenhouse, emulating field conditions) confirmed the results obtained in the laboratory. The combination of attractant and larvicidal agents in a single formulation resulted in a substantial increase in larval mosquito mortality when compared to formulations containing the larvicide agents alone. Conclusions/significance: Collectively, our data demonstrate the potential for the effective use of wax emulsions as slow release matrices for mosquito attractants and control agents. The results indicate that the combination of an oviposition attractant with larvicides could synergize the control of mosquito disease vectors, specifically Cx. quinquefasciatus, a nuisance pest and circumtropical vector of lymphatic filariasis and encephalitis. [ABSTRACT FROM AUTHOR]

Bio-hydrogen, obtained by fermentation of organic residues, is considered a promising source of renewable energy. However, the industrial scale H 2 production from organic waste is far to be realized as technical and economical limitations have still to be solved. Low H 2 yields and lack of industrially robust microbes are the major limiting factors. To look for bacteria with both interesting hydrogen fermentative traits and proper robustness, granular sludge from a brewery full scale Upflow Anaerobic Sludge Blanket (UASB) digester was selected as trove of microbes processing complex substrates. One hundred and twenty bacterial strains, previously isolated from heat-treated granular sludge and genetically identified by 16S rDNA sequencing, were screened for extracellular hydrolytic enzymes on cellulose, hemicellulose, starch, pectin, lipids, protein. The most interesting hydrolytic strains were assessed for their H 2 production from glucose and soluble starch. Two Bacillus sp. strains, namely F2.5 and F2.8, exhibited high H 2 yields and were used as pure culture to convert Organic Fraction of Municipal Solid Waste (OFMSW) into hydrogen. The strains produced up to 61 mL of H 2 per grams of volatile solids and could be considered as good candidates towards the development of industrially relevant H 2 -producing inoculants. This is the first successful application of pure microbial cultures in bio-hydrogen production from OFMSW. [ABSTRACT FROM AUTHOR]

Bacterial-induced mineralization has been explored for protection and consolidation of degraded limestone, concrete and plaster by precipitation of calcium carbonate. It is the first time thatBacillus sphaericuswas used for consolidating the nonsterilized decayed wall paintings samples by immersing them in sterile nutritional media. TheB. sphaericusused in this study produced urease, which catalyzes the hydrolysis of urea (CO(NH2)2) into ammonium (NH4) and carbonate (CO3−2) leading to the precipitation of calcium carbonate. The effect ofB. sphaericuson wall paintings was determined by recording the evolution of culture media chemistry and examining the treated wall paintings under a scanning electron microscope to show the structural and morphological evolution of calcium carbonate that was investigated in wall paintings models. [ABSTRACT FROM AUTHOR]

Biological removal of sulfide, nitrate, and phenol at loading rates of 600 g S/(m day), 900 g N/(m day), and 450 g C/(m day), respectively, from synthetic wastewaters was achieved in an expanded granular sludge bed (EGSB) reactor, whose rates are much higher than literature works and are considered feasible for handling high-strength petrochemical wastewaters without dilution. Effects of C/S ratio (2-2.5:1) on EGSB performance were noted insignificantly. The strains Bacillus sp., Thauera sp., and Pseudomonas sp. were the heterotrophic denitrifiers and the strains Thiobacillus sp., Azoarcus sp., and Sulfurovum sp. were the autotrophic denitrifiers in the EGSB granules. The EGSB reactor experienced biological breakdown at loadings higher than 1200 g S/(m day), 1800 g N/(m day), and 900 g C/(m day) by the following mechanism: high sulfide first inhibits heterotrophic denitrifies ( Bacillus sp. and Pseudomonas sp.), thereby accumulating nitrite in the system; then, the accumulated nitrite inhibits autotrophic denitrifiers ( Thiobacillus sp., Azoarcus sp., and Sulfurovum sp.) to complete breakdown of the system. [ABSTRACT FROM AUTHOR]

The present paper reports the production, purification and biochemical characterization of an extracellular alkaline protease from Bacillus sp. SB12. The enzyme has been used as an alternative to conventional chemicals treatment for dehairing of goat skins. The protease was optimally active at 37 °C and pH 9. Starch at 2% (w/v) was used as the best carbon source and the addition of yeast extract and peptone at 1% each supported the maximum level of protease production in the presence of 5 mM Ca 2+ . Protease purification was performed with ammonium sulphate precipitation at 70% saturated fraction followed by dialysis and gel filtration chromatography using Sephadex G-100. The purified enzyme was homogeneous on non-denaturing PAGE and appeared as a single band with an apparent molecular weight of 41 kDa. This enzyme was moderately thermostable and has a wide pH stability range extending from pH 7 to 11. It showed high tolerance toward surfactants agents and organic solvents while it was completely inhibited by PMSF indicating the serine protease type. Purified protease was used to remove hair from goat skin proving its potential application in leather processing industry. The results revealed that the protease has enhanced the quality and physico-chemical properties of the skins while reducing the pollution. [ABSTRACT FROM AUTHOR]

Recent advances in purification technologies for therapeutic molecules have stirred the research consortium. Mixed mode chromatography, having multiple interactions with the solute molecule, has drawn significant attention due to its overall advantage over traditional ion-exchange and reverse-phase chromatography. Capto adhere, a mixed mode chromatography resin with strong anion-exchange and reverse-phase interaction with solutes, was explored for purification of fibrinolytic enzyme fromBacillus sphaericusMTCC 3672. Static and dynamic resin binding study revealed that 30°C temperature, pH 8, and 0.5 mL/min flow rate were optimum for maximum binding of fibrinolytic enzyme. Maximum static dynamic binding and breakthrough capacities for Capto adhere were 249 and 196 U/mL of resin, respectively. Final purification with Sephadex G 100 gel chromatography resulted in 38-fold purity of fibrinolytic enzyme with 39% enzyme recovery. Purified enzyme was further characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis to homogeneity, and molecular mass was found to be around 55–70 kD. Like most of the serine alkaline proteases, purified fibrinolytic enzyme was stable in a temperature range of 25–40°C and pH range of 7–9. Offshoots of our research findings have revealed a broad application area of mixed mode chromatography. [ABSTRACT FROM PUBLISHER]

The Cry48Aa/Cry49Aa mosquitocidal toxin from Lysinibacillus sphaericus was uniquely composed of a three-domain (Cry) toxin and binary (Bin) toxin-like protein, with high toxicity against Culex spp. However, its mode of action against the target mosquitoes is still unknown. In this study, Cry48Aa, Cry49Aa and its N- and C-terminal truncated proteins were expressed and purified, and the binding affinities of the purified proteins with midgut brush-border membrane fractions (BBMFs) from Culex quin-quefasciatus larvae were performed. The results showed that both Cry48Aa and Cry49Aa have specific and high binding affinity to BBMFs, with dissociation constants of 9.5 ± 1.8 and 25.4 ± 3.8 nM, respectively. Competition assays demonstrated that Cry49Aa C-terminal derivatives were able to bind to the BBMFs, whereas Far-Western dot blot analysis revealed that its N-terminal constructs interacted with Cry48Aa. Nevertheless, larvicidal activity was almost lost when Cry49Aa truncated proteins, either individually or in pairs, combined with Cry48Aa. It is concluded that Cry49Aa is responsible for receptor binding and interaction with Cry48Aa and plays an important role in the mechanism of action of these two-component toxins. [ABSTRACT FROM AUTHOR]

The beneficial effect of microbially induced carbonate precipitation on building materials has been gradually disclosed in the last decade. After the first applications of on historical stones, promising results were obtained with the respect of improved durability. An extensive study then followed on the application of this environmentally friendly and compatible material on a currently widely used construction material, concrete. This review is focused on the discussion of the impact of the two main applications, bacterial surface treatment and bacteria based crack repair, on concrete durability. Special attention was paid to the choice of suitable bacteria and the metabolic pathway aiming at their functionality in concrete environment. Interactions between bacterial cells and cementitious matrix were also elaborated. Furthermore, recommendations to improve the effectiveness of bacterial treatment are provided. Limitations of current studies, updated applications and future application perspectives are shortly outlined. [ABSTRACT FROM AUTHOR]

Ureolytic-type bacteria has been used to improve the strength of cement mortar by the precipitation of calcium carbonate. In the present study Bacillus sphaericus has been used to improve the properties of cement mortar such as setting time, compressive strength and sorptivity. The setting time is found to be unaffected by the presence of bacteria. It is found that compressive strength at both 7-days and 28-days of mortar cube increases with the increase of bacteria concentration. At the optimum bacteria dosage of 107 cells/ml, the average compressive strength increases by 58% (at 7 day) and 23% (at 28 day) over the control specimen. The sorpitivity coefficient decreases as the concentration of bacterial cells increases. The mineralogy and morphology of the calcium carbonate precipitation have been tested by XRD and FESEM. [ABSTRACT FROM AUTHOR]

Background: Lignocellulosic biomass is a renewable, abundant, and inexpensive resource for biorefining process to produce biofuel and valuable chemicals. To make the process become feasible, it requires the use of both efficient pretreatment and hydrolysis enzymes to generate fermentable sugars. Ionic liquid (IL) pretreatment has been demonstrated to be a promising method to enhance the saccharification of biomass by cellulase enzyme; however, the remaining IL in the hydrolysis buffer strongly inhibits the function of cellulase. This study aimed to isolate a potential IL-tolerant cellulase producing bacterium to be applied in biorefining process. Result: One Bacillus sp., MSL2 strain, obtained from rice paddy field soil was isolated based on screening of cellulase assay. Its cellulase enzyme was purified and fractionated using a size exclusion chromatography. The molecular weight of purified cellulose was 48 kDa as revealed by SDS-PAGE and zymogram analysis. In the presence of the IL, 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]) concentration of 1 M, the cellulase activity retained 77.7% of non-IL condition. In addition, the optimum temperature and pH of the enzyme is 50°C and pH 6.0, respectively. However, this cellulase retained its activity more than 90% at 55°C, and pH 4.0. Kinetic analysis of purified enzyme showed that the Km and Vmax were 0.8 mg/mL and 1000 μM/min, respectively. Conclusion: The characterization of cellulase produced from MSL2 strain was described here. These properties of cellulase made this bacterial strain become potential to be used in the biorefining process. [ABSTRACT FROM AUTHOR]