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This research aimed to evaluate the larvicidal activity of the lower doses of commercially synthetic Bacillus thuringiensis israelensis (Vectobac 12 Aqueous Solution (12AS)) against the fourth instar larva. One hundred and fifty blood-fed female anopheles mosquitoes were collected from different resting sites from Abuja Quarters in June 2022 using an aspirator and allowed to breed until the first instar larva appeared. The larvae were monitored and fed with 10% yeast until the third instar emerged. 240 healthy third instar larvae were selected and grouped into three treatments containing sixty (60) larvae each and replicated three times. The first, second and third treatments were respectively treated with 0.84, 0.42 and 0.21ml/l of Vectobac 12AS. Each treatment has a control containing twenty (20) larvae. Larval mortality was determined using a glass rod at an interval of 15 minutes for 24 hours. ANOVA was used to statistically analysed differences in the larval mortality between the treatment and probit analysis was used to determine the lethal concentration (LC) and the lethal time (LT). Mortality of 1(6.7%) and 3(5.0%) were observed in the first treatment (0.84ml/l) after 15 and 30minute of exposure respectively. The highest mortality of 60(100%) was observed in all the treatments after 24 hours of exposure. Statistically, there was no significant difference (F=0.081, P> 0.05). 2.35 ml/l, 5.54 ml/l and 8.15 ml/l was determined to be LC50, LC90 and LC99 respectively and LT50, LT90 and LT99 were found to be, 1809.29min and 2451.34min respectively. Conclusively vectobac 12AS has demonstrated a high level of efficacy as it revealed 100% larval mortality even at a lower recommended dose. Further research should be carried out to study the impact of other biological and environmental factors on the efficacy of vectobac 12AS.

This study evaluated the index and physico-chemical characteristics of lateritic soil classified as A-2-6 (1) in the American Association of State Highway and Transportation Officials (AASHTO) system and SC in the Unified Soil Classification System (USCS) treated with stepped Bacillus sphaericus (Bs) suspension densities (i.e., 0, 1.5 × 108, 6.0 × 108, 1.2 × 109, 1.8 × 109, 2.4 × 109 cells/mL) for varying cementation reagent (Cr) concentrations (i.e., 0.25, 0.5, 0.75 and 1.0 M), using 25 Bs:75 Cr, 50 Bs:50 Cr, and 75 Bs:25 Cr mix ratios, respectively. The results obtained show that the optimum calcium carbonate contents were 9.0%, 8.7%, and 6.5% for the mix ratios stated above, respectively, for Bs (1.2 × 109 cells/mL) and Cr (0.5 M) with urease activity of 80.8 ms/cm and an optimum pH of 8.99. The bio-treatment of soil with 25% bacteria (1.2 × 109 cells/mL) and 75% Cr (0.5 M) mix ratio reduced the liquid limit (LL) of the natural soil from 36.5 to 34.2%, and the plasticity index (PI) from 16.4 to 11.6%. A microanalysis of specimens showed that the treated soil appeared more uniform and aggregated. The findings of the study show that bio-treatment with 25 Bs (1.2 × 109 cells/mL):75 Cr (0.5 M) mix ratio improved the index and physico-chemical properties of the lateritic soil considered in the study. [ABSTRACT FROM AUTHOR]

[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]

This study is conducted to make a commercial suspension in Algeria in replacement to the harmful and expensive insecticide several morphological and biochemical features were done to identify Bacillus sphaericus in the commercial suspension of Solvay & Cie (Brussels). It was found negative in most of the following tests Voges Proskauer, mannitol mobility, Amidon hydrolysis, conversion of glucose and galactose to acids, and respiratory type. It was also able to grow at 65°C and it was resistant to Streptomycin, bacitracin, and susceptible tonchomycin. Five recultivation from one culture to a new medium showed a loss of toxicity (23 times) to L1 and L2. Culex pipiens pipiens. In the course of three months of storage, for the stock solutions kept at +4 and at -18 °C, the poisonous potential of B. sphaericus, which was grown only once on MBS-tryptose from the commercial suspension, changes between 80 and 123 times. When compared to an emulsion frozen in glycerin, the toxicity of B. sphaericus held at +4 °C is often found to be more stable, especially over the last two weeks. In comparison to the larvicidal activity of the solution held at +4 °C, between the second and the twelfth week, the resistance of the solution stored at -18 °C has deteriorated over a two-week period by a factor of 2.5 to 6. B. sphaericus was only once grown on MBS-tryptose from the commercial suspension and has a variable toxic potential each toxicity test was repeated 3 times with controlled experiments. These experiments were executed in 2015 at Annaba university applied neuroendocrinology laboratory. These series of experiments were executed in 2015 at Annaba university labs. basically to study the effectiveness of B. sphaericus bacteria after the recultivation and the influence of the conservation of it under two temperatures +4 °C and -18 °C to counter Culex pipiens pipiens.

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]

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.

Aim of this study was assessing the characteristics of dispersive soil based on percentage of dispersion and degree of dispersion and to improve the strength of soil using microbes. This research has utilized the Microbial Induced Calcium Carbonate process (MICP) in conjunction with jute fibre for the improvement the erosive resistance in dispersive soil. Calcite formation occurred as a consequence of microbial biomass in voids of dispersive soil. Calcium carbonate was synthesized in the gaps of the soil matrix during the microbiological process. Bacillus sphaericus bacteria were used in this experiment, along with a 1 cm length of jute raw fibre of 1 cm long and a cell concentration of 6.4E+08 CFU mL-1. The findings of the Unconfined compressive strength (UCS) test showed following of MICP treatment with and without jute fibre augmentation, UCS values causing the 11 and 13 times. Crumb test findings showed no colloidal solution was generated after microbial treatment, which was used for confirmation of the degree of dispersiveness reduction. Addition of jute fibres indicating better precipitation values of more than 4% due to the internal bonding strength. Ground renovation through microbial cementation yielded promising benefits, suggesting sustainability. [ABSTRACT FROM AUTHOR]

Microbiologically induced calcite precipitation, or calcium carbonate CaCO3, is used in remediating cracks and fissures in concrete. Since the microbial activity is pollution-free, natural, that process is extremely desired and may solve concrete cracking without sacrificing mechanical properties. The effects of different nutrient on the self-healing process are elucidated. Nutrients provide the required sources of energy for the bacterial growth and metabolic activities. A species of bacteria Bacillus sphaericus was added to the cement mix at a ratio of 0.6% of cement weight with three organic compounds for nutrients (calcium lactate, yeast extract and peptone) at 0.30% of cement weight. Effects on setting time, rate of water absorption, compressive strength and flexural strength were studied. It was found that bacteria nutrition acts as an accelerator for cement pastes for initial setting time mortar, while acts as a retarder of cement pastes for final setting time for all bacterial compared to control mortar. Finally, bacterial mortars with different types of nutrients showed an increase in compressive and flexural strengths with yeast extract showing the most promising enhancements, resulting in 26.5 and 60% increase in compressive and flexural strength respectively.

This study evaluated the index and physico-chemical characteristics of lateritic soil classified as A-2-6 (1) in the American Association of State Highway and Transportation Officials (AASHTO) system and SC in the Unified Soil Classification System (USCS) treated with stepped Bacillus sphaericus (Bs) suspension densities (i.e., 0, 1.5 × 108, 6.0 × 108, 1.2 × 109, 1.8 × 109, 2.4 × 109 cells/mL) for varying cementation reagent (Cr) concentrations (i.e., 0.25, 0.5, 0.75 and 1.0 M), using 25 Bs:75 Cr, 50 Bs:50 Cr, and 75 Bs:25 Cr mix ratios, respectively. The results obtained show that the optimum calcium carbonate contents were 9.0%, 8.7%, and 6.5% for the mix ratios stated above, respectively, for Bs (1.2 × 109 cells/mL) and Cr (0.5 M) with urease activity of 80.8 ms/cm and an optimum pH of 8.99. The bio-treatment of soil with 25% bacteria (1.2 × 109 cells/mL) and 75% Cr (0.5 M) mix ratio reduced the liquid limit (LL) of the natural soil from 36.5 to 34.2%, and the plasticity index (PI) from 16.4 to 11.6%. A microanalysis of specimens showed that the treated soil appeared more uniform and aggregated. The findings of the study show that bio-treatment with 25 Bs (1.2 × 109 cells/mL):75 Cr (0.5 M) mix ratio improved the index and physico-chemical properties of the lateritic soil considered in the study.

Although Culex species are considered to be equally affected by control measures targeting malaria vectors, there is still not enough evidence of the impact of interventions such as larviciding on the distribution of these mosquito species. The present study assessed the impact of a larviciding trial targeting malaria vectors on Culex mosquito species in the city of Yaoundé, Cameroon. A cluster randomized trial comparing 13 treated clusters and 13 untreated clusters was implemented. Data were collected at baseline and during the larviciding intervention, from March 2017 to November 2020. The microbial larvicide VectoMax G was applied once every 2 weeks in the intervention areas. Adult mosquitoes were collected using CDC light traps in both intervention and non-intervention areas and compared between arms. Globally, larviciding intervention was associated with 69% reduction in aquatic habitats with Culex larvae and 36.65% reduction of adult Culex densities in houses. Adult Culex densities were reduced both indoors (35.26%) and outdoors (42.37%). No change in the composition of Culex species was recorded. The study suggests a high impact of larviciding on Culex mosquito species distribution. The impact of the intervention can be improved if typical Culex breeding habitats including pit latrines are targeted.

BackgroundChemical-based malaria vector control interventions are threatened by the development of insecticide resistance and changes in the behavior of the vectors, and thus require the development of alternative control methods. Bacterial-based larvicides have the potential to target both insecticide resistant and outdoor-biting mosquitoes and are safe to use in the environment. However, the currently available microbial larvicide formulations have a short duration of activity requiring frequent re-applications which increase the cost of control interventions. This study was designed to evaluate the efficacy and duration of activity of two long-lasting formulations of Bacillus thuringiensis var. israelensis (Bti) and Bacillus sphaericus (Bs) (LL3 and FourStar®) under field conditions in western Kenya highlands.MethodsThree sites were selected for this study in the highlands of western Kenya. In each site, one hundred anopheline larval habitats were selected and assigned to one of three arms: (i) LL3; (ii) FourStar®; and (iii) untreated control larval habitats. Four types of larval habitats were surveyed: abandoned gold mines, drainage canals, fish ponds and non-fish ponds. The habitats were sampled for mosquito larvae by using a standard dipping technique and collected larvae were recorded according to the larval stages of the different Anopheles species. The larvicides were applied at manufacturers' recommended dosage of 1 briquette per 100 square feet. Both treatment and control habitats were sampled for mosquito larvae immediately before treatment (day 0), and then at 24 hours, 3 days and weekly post-treatment for 5 months.ResultsOverall larval density in treatment habitats was significantly reduced after application of the two microbial larvicides as compared to the control habitats. Post-intervention reduction in anopheline larval density by LL3 was 65, 71 and 84% for 1 day, 2 weeks and 4 weeks, respectively. FourStar® reduced anopheline larval density by 60, 66 and 80% for 1 day, 2 weeks and 4 weeks, respectively. Comparisons between the treatments reveal that LL3 and FourStar® were similar in efficacy. A higher reduction in Anopheles larval density was observed in the abandoned goldmines, while drainage canals had the lowest reduction.ConclusionsBoth LL3 and FourStar® long-lasting microbial larvicides were effective in reducing immature stages of An. gambiae complex and An. funestus group species, with significant reductions lasting for three months post-application.

In microbial induced calcium carbonate precipitation (MICP) system, yeast extract (YE) is needed for spores germination. The aim of this research is to evaluate the minimum amount of YE in mortar that allows spores of Bacillus sphaericus to germinate with limited negative effect on mortar properties. Two YE concentrations of 2 and 5 g/l were tested and compared to a reference without YE. To protect the bacteria in the mortar matrix, spores or cells were encapsulated into porous expanded clay. The ureolytic activity of bacteria with YE variation, the mechanical properties and the healing ability of mortar were assessed. The results show that a YE concentration of 2 g/l provided acceptable mortar properties, while it was sufficient for spores to germinate and provide a satisfactory healing ability to resulting mortar. When vegetative cells are used as a healing agent, it is best to omit yeast extract from the mortar mixture.

Some pesticides are applied directly to aquatic systems to reduce numbers of mosquito larvae (larvicides) and thereby reduce transmission of pathogens that mosquitoes vector to humans and wildlife. Sustained, environmentally-safe control of larval mosquitoes is particularly needed for highly productive waters (e.g., catchment basins, water treatment facilities, septic systems), but also for other habitats to maintain control and reduce inspection costs. Common biorational pesticides include the insect juvenile hormone mimic methoprene and pesticides derived from the bacteria Bacillus thuringiensis israelensis, Lysinibacillus sphaericus and Saccharopolyspora spinosa (spinosad). Health agencies, the public and environmental groups have especially debated the use of methoprene because some studies have shown toxic effects on non-target organisms. However, many studies have demonstrated its apparent environmental safety. This review critically evaluates studies pertinent to the environmental safety of using methoprene to control mosquito larvae, and provides concise assessments of the bacterial larvicides that provide sustained control of mosquitoes. The review first outlines the ecological and health effects of mosquitoes, and distinguishes between laboratory toxicity and environmental effects. The article then interprets non-target toxicity findings in light of measured environmental concentrations of methoprene (as used in mosquito control) and field studies of its non-target effects. The final section evaluates information on newer formulations of bacterially-derived pesticides for sustained mosquito control. Results show that realized environmental concentrations of methoprene were usually 2-5µg/kg (range 2-45µg/kg) and that its motility is limited. These levels were not toxic to the vast majority of vertebrates and invertebrates tested in laboratories, except for a few species of zooplankton, larval stages of some other crustaceans, and small Diptera. Studies in natural habitats have not documented population reductions except in small Diptera. Bacterial larvicides showed good results for sustained control with similarly limited environmental effects, except for spinosad, which had broader effects on insects in mesocosms and temporary pools. These findings should be useful to a variety of stakeholders in informing decisions on larvicide use to protect public and environmental health in a 'One Health' framework.

Developing bio-based self-healing concrete aims to minimize durability problems related to cracking. In this study, MICP was used as a smart and eco-friendly approach to produce bio-based durable materials. Bacillus pasteurii (BP) and Bacillus sphaericus (BS) were added into mortar mixtures with 0.25% and 0.5% cement weight. All treated samples exhibited a significant decline in water uptake, capillary permeability, and volume of permeable voids, as compared to control with no bacteria. All treated samples showed significant increase in compressive strength by 28–50%, after 28 days of curing. At the age of 120 days, the flexural strength of all treated samples was significantly increased by 19.29–65.94%. SEM imaging and EDAX confirmed that treated samples were denser with less voids due to MICP. DTA verified that the calcite amount and the crystallinity degree were improved in treated samples. Load deflection of bacterial Reinforced-Laminates had less deformation than control. Reloaded bacterial Reinforced-Laminates exhibited excellent restoration of physico-mechanical properties and performance, after 28, 90, and 120 days, confirming the healing process. Microbial self-healing is an innovative approach for continuous repair of micro-cracks in concrete, improving its durability, thus can reduce the maintenance costs.

BackgroundOutdoor 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.MethodsThe study evaluated FourStar™ 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.ResultsIn semi-natural conditions, the FourStar™ briquets 180-days formulation completely inhibited mosquito pupal production in the first 3 months, and then reduced pupal productivity by 87-98% (P

[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]

Abstract Background Vector control with Bacillus sphaericus (Bs) is an effective way to block the transmission of malaria. However, in practical application of Bs agents, a sublethal dose effect was often caused by insufficient dosing, and it is little known whether the Bs exposure would affect the surviving mosquitoes’ vector capacity to malaria. Methods A sublethal dose of the Bs 2362 strain was administrated to the early fourth-instar larvae of Anopheles dirus to simulate shortage use of Bs in field circumstance. To determine vector competence, mosquitoes were dissected and the oocysts in the midguts were examined on day 9–11 post-infection with Plasmodium yoelii. Meanwhile, a SYBR quantitative PCR assay was conducted to examine the transcriptional level of the key immune molecules of mosquitoes, and RNA interference was utilized to validate the role of key immune effector molecule TEP1. Results The sublethal dose of Bs treatment significantly reduced susceptibility of An. dirus to P. yoelii, with the decrease of P. yoelii infection intensity and rate. Although there existed a melanization response of adult An. dirus following challenge with P. yoelii, it was not involved in the decrease of vector competence as no significant difference of melanization rates and densities between the control and Bs groups was found. Further studies showed that Bs treatment significantly increased TEP1 expression in the fourth-instar larvae (L4), pupae (Pu), 48 h post-infection (hpi) and 72 hpi (P < 0.001). Further, gene-silencing of TEP1 resulted in disappearance of the Bs impact on vector competence of An. dirus to P. yoelii. Moreover, the transcriptional level of PGRP-LC and Rel2 were significantly elevated by Bs treatment with decreased expression of the negative regulator Caspar at 48 hpi, which implied that the Imd signaling pathway was upregulated by Bs exposure. Conclusions Bs exposure can reduce the vector competence of An. dirus to malaria parasites through upregulating Imd signaling pathway and enhancing the expression of TEP1. The data could not only help us to understand the impact and mechanism of Bs exposure on Anopheles’ vector competence to malaria but also provide us with novel clues for wiping out malaria using vector control.

Bacterial larvicides Bacillus thuringiensis var. israelensis (Bti) and Bacillus sphaericus (Bs) have been used extensively for mosquito control. However, their efficacy varies greatly mainly due to factors related to target mosquitoes, larval habitat conditions, and inherent larvicide properties. We evaluated the efficacy of Bti (Bactivec®) and Bs (Griselesf®) for control of Anopheles gambiae complex, Culex quinquefasciatus and Aedes aegypti larvae under laboratory and semi-field conditions in northeastern Tanzania. Laboratory bioassays were conducted with five to six different concentrations of Bti and Bs, replicated four times and the experiment repeated on three different days. Larvae mortality was recorded at 24 or 48 h after the application of larvicide and subjected to Probit analysis. Laboratory bioassays were followed by semi-field trials to establish initial and residual activity of Bti and Bs. Semi-field trials were conducted in artificial larval habitats in the open sunlit ground and in “mosquito spheres”. These artificial larval habitats were colonized with mosquito larvae, treated with Bti and Bs, and the impact of treatments on mosquito larvae was monitored daily. Lethal concentration values that caused 50% and 95% mortalities of test larvae (LC50 and LC95) showed that An. gambiae complex and Cx. quinquefasciatus tested were highly susceptible to Bti and Bs under laboratory conditions. Likewise, larvae of Ae. aegypti were highly susceptible to Bti, with LC95 value as low as 0.052 mg/l. However, Ae. aegypti larvae were not susceptible to Bs under practical doses of laboratory settings. In semi-field trials, all treatment dosages for Bti provided 91.0–100% larval mortality within 24 h whereas Bs resulted in 96.8–100% larval mortality within the same time-frame. Bs had a more prolonged residual activity, with pupal reductions range of 55.7–100% for 9 days at all application rates while the corresponding pupal reduction with Bti was 15.4–100% for 5 days. Due to the low residual activity of Bti and Bs tested, weekly application at a maximum label rate would be appropriate to reduce mosquito larvae in natural larval habitats. Based on laboratory findings, Bs product tested would not be recommended for use in the control of Ae. aegypti.

Abstract Several trials and reviews have outlined the potential role of larviciding for malaria control in sub-Saharan Africa (SSA) to supplement the core indoor insecticide-based interventions. It has been argued that widespread use of long-lasting insecticide-treated nets (LLINs) and indoor residual spraying (IRS) interventions in many parts of Africa result in many new areas with low and focal malaria transmission that can be targeted with larvicides. As some countries in SSA are making good progress in malaria control, larval source management, particularly with bacterial larvicides, could be included in the list of viable options to maintain the gains achieved while paving the way to malaria elimination. We conducted a review of published literature that investigated the application of bacterial larvicides, Bacillus thuringiensis var. israelensis (Bti) and/or Bacillus sphaericus (Bs) for malaria vector control in SSA. Data for the review were identified through PubMed, the extensive files of the authors and reference lists of relevant articles retrieved. A total of 56 relevant studies were identified and included in the review. The findings indicated that, at low application rates, bacterial larvicide products based on Bti and/or Bs were effective in controlling malaria vectors. The larvicide interventions were found to be feasible, accepted by the general community, safe to the non-target organisms and the costs compared fairly well with those of other vector control measures practiced in SSA. Our review suggests that larviciding should gain more ground as a tool for integrated malaria vector control due to the decline in malaria which creates more appropriate conditions for the intervention and to the recognition of limitations of insecticide-based vector control tools. The advancement of new technology for mapping landscapes and environments could moreover facilitate identification and targeting of the numerous larval habitats preferred by the African malaria vectors. To build sustainable anti-larval measures in SSA, there is a great need to build capacity in relevant specialties and develop organizational structures for governance and management of larval source management programmes.

Abstract Background Biotic and abiotic factors have been reported to affect the larvicidal efficacy of Bacillus thuringiensis israelensis (Bti) and Bacillus sphaericus (Bs), although the extent to which they are affected has been poorly documented. This paper studies the effect of sunlight exposure on the efficacy of a new larvicide formulation based on both Bti and Bs, herein after referred to as BTBSWAX, applied against two different larval stages. Methods The emergence of inhibition exhibited by BTBSWAX at three different dosages (1 g/m2, 1.5 g/m2, and 2 g/m2) was monitored under semi-field conditions using a total of 32 containers comprising 16 that were covered and 16 that were uncovered. Two experiments were conducted using first- and second-instar larvae of Anopheles gambiae, respectively. Results BTBSWAX at 2 g/m2 in covered containers exhibited high emergence inhibition (> 80%) when larvae were exposed from 1st instar on day-6 post-treatment, whereas the emergence inhibition was only 28% in uncovered containers. For larvae exposed from 1st instar on day-12 post-treatment, the emergence inhibition was moderate (70%) in covered containers but was low (

In recent years, the need for land has been increasing due to the increasing population, especially in big cities. In addition to the use of lands that meet sufficient criteria in terms of foundation soils, it has become compulsory to use lands that do not meet these criteria. In lands that do not meet sufficient criteria in terms of basic soils, improvement is made by using classical additives such as lime, fly ash, blast furnace slag. However, these additives are not environmentally friendly as they increase CO2 emissions in nature. Therefore, in recent years, there has been an interest in new environmentally friendly additives alternative to these additives. One of these additives is Bacillus Sp. which provides improvement in the soils by producing CaCO3 in the soil where it is injected. In this study, strength and swelling pressures were investigated under freeze-thaw cycles on high plasticity clay (CH) and sandy clay (SC) soils injected with Bacillus Sp. According to the results, it was determined that Bacillus Sp. contributed positively to the improvement of the strength and swelling pressure parameters of soils. [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]

Abstract Background Chemical-based malaria vector control interventions are threatened by the development of insecticide resistance and changes in the behavior of the vectors, and thus require the development of alternative control methods. Bacterial-based larvicides have the potential to target both insecticide resistant and outdoor-biting mosquitoes and are safe to use in the environment. However, the currently available microbial larvicide formulations have a short duration of activity requiring frequent re-applications which increase the cost of control interventions. This study was designed to evaluate the efficacy and duration of activity of two long-lasting formulations of Bacillus thuringiensis var. israelensis (Bti) and Bacillus sphaericus (Bs) (LL3 and FourStar®) under field conditions in western Kenya highlands. Methods Three sites were selected for this study in the highlands of western Kenya. In each site, one hundred anopheline larval habitats were selected and assigned to one of three arms: (i) LL3; (ii) FourStar®; and (iii) untreated control larval habitats. Four types of larval habitats were surveyed: abandoned gold mines, drainage canals, fish ponds and non-fish ponds. The habitats were sampled for mosquito larvae by using a standard dipping technique and collected larvae were recorded according to the larval stages of the different Anopheles species. The larvicides were applied at manufacturers’ recommended dosage of 1 briquette per 100 square feet. Both treatment and control habitats were sampled for mosquito larvae immediately before treatment (day 0), and then at 24 hours, 3 days and weekly post-treatment for 5 months. Results Overall larval density in treatment habitats was significantly reduced after application of the two microbial larvicides as compared to the control habitats. Post-intervention reduction in anopheline larval density by LL3 was 65, 71 and 84% for 1 day, 2 weeks and 4 weeks, respectively. FourStar® reduced anopheline larval density by 60, 66 and 80% for 1 day, 2 weeks and 4 weeks, respectively. Comparisons between the treatments reveal that LL3 and FourStar® were similar in efficacy. A higher reduction in Anopheles larval density was observed in the abandoned goldmines, while drainage canals had the lowest reduction. Conclusions Both LL3 and FourStar® long-lasting microbial larvicides were effective in reducing immature stages of An. gambiae complex and An. funestus group species, with significant reductions lasting for three months post-application.

Abstract 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 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.

• 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]

There is a growing need in the construction industry to improve transfer and durability aspects of Portland pozzolana cement. Ureolytic bacteria have recently emerged as potential micro-organisms well known for precipitation of calcium carbonate through microbiologically induced calcite precipitation (MICP) process. MICP process has emerged as a viable mechanism for improvement of the PPC performance. This paper presents an in-depth discussion on the effects of Bacillus pseudofirmus, Bacillus sphaericus, Sporosarcina pasteurii, Bacillus cereus, Bacillus megaterium and Bacillus subtilis on some selected physico-mechanical properties of cement-based materials. These properties include standard consistency, setting time, compressive strength, water absorptivity, porosity and chloride ingress. The influence of pH, temperature and various bacteria nutrient requirements on optimum MICP process is also presented. In conclusion, benefits and drawbacks on the use of MICP has been discussed. MICP as a potential technique for improvement of physico-mechanical properties as well as repair of cracked cement-based structures has been discussed. [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]

Objective: To isolate, characterize and evaluate toxicity of Bacillus sphaericus (B. sphaericus) from beach area of Lombok Island. Methods: Soil was collected from determined locations and suspended in sterile physiological saline water. After heat shock was applied, suspension was spread on NYSM agar medium. Colonies grown were then observed and isolated. Colony, cell morphology, and biochemical/physiological characteristics were tested and compared to B. sphaericus 2362 as standard. Initial toxicity testing was done against three species of mosquito larvae (Culex quinquefasciatus, Anopheles aconitus and Aedes aegypti) and isolates that showed more than 50% larvae killing will be assayed to obtain LC50 and LC90 values within 48 h. PCR technique were conducted to obtain 16s rDNA amplicon for sequencing and to detect toxin-expressing genes (using multiplex PCR). Results: Twenty isolates of B. sphaericus have been collected from 20 determined locations and their characteristics were in agreement with standard B. sphaericus characteristics. Bioassay testing showed that four isolates (namely isolate MNT, SLG, TJL2 and PLG) were mildly toxic against all larvae. The rests were either low toxic or non-toxic at all. Phylogenetic analysis showed that all four isolates were clustered with other known mildly and highly toxic strains. The multiplex PCR result showed four toxic isolates owned 1–2 bands from Bin toxin genes and three bands from Mtx toxin genes, whereas 16 isolates with low to non-toxic characteristics showed only three bands from Mtx toxin genes. Conclusions: Four toxic isolates of B. sphaericus were isolated from beach area of Lombok Island. They showed mild toxicity against larvae of three mosquito species.

Abstract Background Bacillus sphaericus is a mosquito-larvae pathogen which proliferates in the host cadavers, spreading and preserving the infection within the larval habitats for prolonged periods. In this pilot field study, we presented B. sphaericus-containing attractive sugar baits (ASB) to wild Anopheles sergentii adults, with the assumption that bait-fed, B. sphaericus-carrying mosquitoes are able to efficiently transmit the pathogen to the larval habitats, causing larval mortality and leading to a decrease in the subsequent adult population. Methods The experiment was conducted over 75 days in two desert-surrounded streamlets. Blooming Ochradenus baccatus bushes were sprayed with bait solutions consisting of sugar and food dye marker solutions, with or without B. sphaericus at the experimental and control streamlets, respectively. Adult mosquito and larvae numbers were monitored before and after the treatment application, and the proportion of bait-fed adults was determined by visual inspection for dye presence. Results Presence of food dye confirmed a large fraction of the adult mosquito population (70%-75%) readily ingested Bacillus sphaericus- containing bait. By the end of the study period, the larval population at the experimental site was six-fold smaller than the concurrent larval population at the control site. The ensuing adult An. sergentii population was also reduced to about 60% at the experimental site, while the adult mosquito population at the control site had increased 2.4 fold over the same time-frame. The reduction in adult mosquito numbers became apparent after a lag time (10 days), suggesting the treatment had minimal effect on adult longevity, also indicated by the post-treatment increase in the proportion of old mosquitoes and concomitant decrease in the proportion of young mosquitoes. Conclusions Presentation of B. sphaericus-containing ASB substantially impacts the larval population, which in turn leads to a significant reduction of the ensuing numbers of adult mosquitoes. Although such outcomes may be the result of other causes, these preliminary results raise the possibility that adult mosquitoes can efficiently transmit the pathogen into the larval habitats. The transfer of B. sphaericus via contaminated adult mosquito carriers may allow introduction of pathogens to breeding places which are dispersed, hard to find, or difficult to access.

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]

Abstract The detergent-compatible alkaline protease was produced from the bacterial strain Bacillus sp. APP-07 isolated from Laundromat soil of Solapur, Maharashtra, India. The culture was grown in 1000 ml capacity baffled flask with a working volume of 100 ml and incubated at 55 °C for 33 h on a rotary shaker. After incubation, alkaline protease was partially purified by the sequential method of acetone precipitation followed by nominal molecular weight limit (NMWL) cut-off ultrafiltration using 50 K and 10 K filters. Finally, Sephadex G-100 gel filtration chromatographic purification was performed to obtain 3.12 fold purified alkaline protease enzyme with a 66.67% final yield. The purified enzyme showed 31907.269 units (U) of enzyme activity containing 8741.718 U/mg of specific enzyme activity. The molecular weight of the enzyme was confirmed about 33.0 kDa (kDa) by the SDS-PAGE analysis. The purified enzyme was stable at higher pH and temperature range, with an optimum pH 10.5 and temperature 55 °C. The enzyme showed excellent stability and compatibility in various detergents, surfactants, bleach, and oxidizing agents. The enzyme activity enhanced in the presence of Ca2+, Cu2+, and surfactants, whereas; the phenylmethylsulphonyl fluoride (PMSF) and Diisopropyl fluorophosphate (DFP) completely inhibit the enzymatic activity, which pointed out that the enzyme affiliated to serine-centered metalloproteases family. In conclusion, the remarkable tolerance and stability of the enzyme explored the promising candidature for the several potential applications in the laundry detergents. The sustainability of the enzyme might serve several possible applications in the laundry detergents, leather industries, and other harsh industrial processes. [ABSTRACT FROM AUTHOR]

Abstract Inulinase are industrial food enzymes which have gained much attention in recent scenario. In this study, Inulinase producing eight bacterial colonies were isolated and screened from three different plant root tubers soil sample. Among 8 inulinase producing colonies, the higher yielding colony was selected with 25.10 U/mL for further studies. The best inulinase producing colony was identified by partial 16S rRNA gene sequence as Bacillus sp. The crude inulinase was purified by using ammonium sulphate precipitation, dialysis and ion exchange chromatography on DEAE – sephacel and obtained 1.9 purification fold with total activity 293 U. The purified enzyme was subjected to characterization studies and it was found to be stable at 30–60 °C and optimum temperature was at 55 °C. The enzyme was stable at pH 3.0–7.0 and optimum pH was at 6.5. The K m and V max value for inulinase was found to be 0.117 mg/mL and 4.45 μmol min mg−1 respectively, demonstrate its greater affinity. Hence, this enzyme can be widely used for the production of fructose, and fructooligosaccharides, which are important ingredients in food and pharmaceutical industry. [ABSTRACT FROM AUTHOR]

Abstract Fungal and bacterial pathogens infect a diverse range of hosts including various plant and animal species. Fungal and bacterial diseases, especially of plants and aquatic animals, such as fish, lead to significant damage to crops and aquaculture, respectively, worldwide. The present study was conducted to isolate and characterize potent Bacillus strains with significant antagonistic activity against the major plant and fish pathogenic fungi and bacteria. We randomly collected 22 isolates of Bacillus from the soil, rhizosphere, and sediment from different parts of Bangladesh. Initial characterization, based on in vitro antagonistic activity on the culture plate, resulted in the selection of four gram-positive Bacillus sp. isolates. Among these, the isolate BC01, obtained from soil demonstrated the highest broad-spectrum anti-bacterial and anti-fungal activities. We confirmed the genus of BC01 to be Bacillus by morphological and biochemical tests as well as using molecular data analysis tools, including the study of 16s rDNA, phylogenetic relationship, and evolutionary divergence scores. The isolate significantly inhibited the mycelial growth of the plant pathogen, Penicillium digitatum and fish pathogen, Aphanomyces invadans in vitro. The anti-bacterial effect of the isolate was also evaluated against Pseudomonas spp. and Xanthomonas spp., the two deadliest plant pathogens, and Aeromonas veronii , Pseudomonas fluorescens , and Streptococcus iniae , three major fish pathogens that are primarily responsible for global aquaculture loss. The results of the present study could pave the way for developing potent drugs to combat microbial infection of plants and fish. [ABSTRACT FROM AUTHOR]