Bacillus Safensis Research Articles

Bacillus safensis JG-B5T affects the fate of selenium by extracellular production of colloidally less stable selenium nanoparticles

Understanding the impact of microorganisms on the mobility of selenium (Se) is important for predicting the fate of toxic Se in the environment and improving wastewater treatment technologies. The bacteria strain Bacillus safensis JG-B5T, isolated from soil in a uranium mining waste pile, can influence the Se speciation in the environment and engineered systems. However, the mechanism and conditions of this process remain unknown. This study found that the B. safensis JG-B5T is an obligate aerobic microorganism with an ability to reduce 70% of 2.5 mM selenite to produce red spherical biogenic elemental selenium nanoparticles (BioSeNPs). Only extracellular production of BioSeNPs was observed using transmission electron microscopy. The two-chamber reactor experiments, genome analysis and corona proteins identified on BioSeNPs suggested that the selenite reduction process was primarily mediated through membrane-associated proteins, like succinate dehydrogenase. Extracellular presence and low colloidal stability of BioSeNPs as indicated by ζ-potential measurements, render B. safensis JG-B5T an attractive candidate in wastewater treatment as it provides easy way of recovering Se while maintaining low Se discharge. As this microorganism decreases Se mobility, it will affect Se bioavailability in the environment and decreases its toxicity.

Characterisation of bacteria isolated from the stingless bee, Heterotrigona itama, honey, bee bread and propolis.

Bacteria are present in stingless bee nest products. However, detailed information on their characteristics is scarce. Thus, this study aims to investigate the characteristics of bacterial species isolated from Malaysian stingless bee, Heterotrigona itama, nest products. Honey, bee bread and propolis were collected aseptically from four geographical localities of Malaysia. Total plate count (TPC), bacterial identification, phenotypic profile and enzymatic and antibacterial activities were studied. The results indicated that the number of TPC varies from one location to another. A total of 41 different bacterial isolates from the phyla Firmicutes, Proteobacteria and Actinobacteria were identified. Bacillus species were the major bacteria found. Therein, Bacillus cereus was the most frequently isolated species followed by Bacillus aryabhattai, Bacillus oleronius, Bacillus stratosphericus, Bacillus altitudinis, Bacillus amyloliquefaciens, Bacillus nealsonii, Bacillus toyonensis, Bacillus subtilis, Bacillus safensis, Bacillus pseudomycoides, Enterobacter asburiae, Enterobacter cloacae, Pantoea dispersa and Streptomyces kunmingensis. Phenotypic profile of 15 bacterial isolates using GEN III MicroPlate™ system revealed most of the isolates as capable to utilise carbohydrates as well as amino acids and carboxylic acids and derivatives. Proteolytic, lipolytic and cellulolytic activities as determined by enzymatic assays were detected in Bacillus stratosphericus PD6, Bacillus amyloliquefaciens PD9, Bacillus subtilis BD3 and Bacillus safensis BD9. Bacillus amyloliquefaciens PD9 showed broad-spectrum of antimicrobial activity against Gram-positive and Gram-negative bacteria in vitro. The multienzymes and antimicrobial activities exhibited by the bacterial isolates from H. itama nest products could provide potential sources of enzymes and antimicrobial compounds for biotechnological applications.

Five-factor-at-a-time (FFAT) approach for optimal production of an extracellular RNase from Bacillus safensis RB-5

A Gram-positive, rod-shaped, endospore-forming, and RNA-degrading bacterium RB-5 was isolated from a soil sample. Based on 16-rDNA gene sequence, the bacterium RB-5 was identified as Bacillus safensis (Accession number KX443714.1). The bacterium appeared to be related to Bacillus safensis KL-052, an other-member of genus Bacillus. One-factor-at-a-time (OFAT) and Response Surface Methodology (RSM) statistical approaches were used to optimize the fermentation broth to obtain an improved extracellular RNase production from B. safensis RB-5. These approaches improved RNase activity of B. safensis KL-052 from 4.26 to 7.85 U/mL. The OFAT approach was used to study the effects of supplementation of carbon, nitrogen and physical conditions, which included temperature, pH and agitation rate on extracellular RNase production by B. safensis KL-052. Five variables screened by Central Composite Design (CCD) were employed to evaluate their interactive effects on RNase production by the organism. CCD selected 25 factorial values obtained by the statistical approach were peptone 1.13% (w/v), sodium nitrate 1.13% (w/v), MgSO4 0.06% (w/v), pH 8.5, and temperature 35 °C for RNase production by B. safensis. The highest predicted value of RNase was 7.05 U/ml while actual obtained value was 7.85 U/ml that was ∼84% and 1.84-fold higher than OFAT approach.

대장균군 건조필름의 위양성과 위음성 균주 분리 동정

The detection efficiency on dry rehydratable films and identification of false positive and false negative colonies to improve the detection accuracy of coliform dry rehydratable films were evaluated in this study. A total of 173 commercial spices and jeotgal were used in this study. The detection accuracy for coliform on 3M Petrifilm coliform count film was 97.9%, and false negative was 2.1% (nine strains). For Sanita-kun coliform count film, the detection accuracy was 97.3%, and false positive was 2.7% (six strains). The 3M Petrifilm coliform count film and Sanita-kun coliform count film showed similar detection accuracies. The biochemical identification of the false negative colonies on 3M Petrifilm coliform count film revealed the presence of Escherichia hermannii and Pantoea spp., which were included in the coliform group. The false positive colonies on Sanita-kun coliform count film were identified as Bacillus licheniformis, Bacillus rhizosphaerae, Bacillus clausi, Bacillus pumilus, and Bacillus safensis, which were gram positive and oxidase positive. In order to improve the detection accuracy for coliform, it is necessary to further incubate over 48 h to confirm the gas generation in 3M Petrifilm coliform count film. In Sanita-kun coliform count film, additional biochemical tests such as the gram stain and oxidase tests are necessary.

Characterization of marine bacterial carbonic anhydrase and their CO2 sequestration abilities based on a soil microcosm

The novel technology of biological carbon sequestration using microbial enzymes have numerous advantages over conventional sequestration strategies. In the present study, extracellular carbonic anhydrase (CA) producing bacteria were isolated from water samples in the Arabian Sea, India. A potential isolate, Bacillus safensis isolate AS-75 was identified based on 16S rDNA sequence analysis. The culture conditions suitable for CA production were 32 °C incubation temperature with 4% NaCl and 10 mM Zn supplementation. Experimental optimization of culture conditions enhanced enzyme activity to 265 U mL−1. CA specific gene was characterized and based on the analysis, the CA of B. safensis isolate AS-75 was a leucine (11.3%) with α-helices as the dominant component in its secondary structure. Based on soil microcosm studies, CA could sequester CO2 by 95.4% ± 0.11% in sterilized soil with enzyme microcosm. Hence, the application of enzyme was found to be more effective in removing CO2.

Microbial enhanced oil recovery using a biosurfactant produced by Bacillus safensis isolated from mangrove microbiota - Part I biosurfactant characterization and oil displacement test

After primary and secondary recovery operations, the majority of the original oil in place remains in the reservoir due to physical and geological limitations. Thus, increasing oil recovery yields and reducing operational costs are major goals of the oil industry and efforts are being made to develop economic methods of enhanced oil recovery. One alternative method is the use of the microbiological enhanced oil recovery method (MEOR), which uses microorganisms or their metabolites, including biosurfactants, to mobilize the oil trapped in reservoirs and increase the oil recovery factor. This study aimed to evaluate the potential of a pumilacidin produced by Bacillus safensis CCMA-560 to increase oil recovery in a laboratory scale MEOR process. This bioactive molecule was previously isolated from a mangrove, increasing its potential to contribute to a more sustainable economy and to the environment. The critical micelle concentration (CMC) of the biosurfactant was determined by surface tension and thermal gravimetric analysis (TGA) was performed to evaluate if its thermal stability is consistent with the average reservoir temperature. Surface and interfacial tension measurements were performed to investigate the interfacial activity behaviors of the biosurfactant with oil and brine. Core flood experiments showed that this biosurfactant has a great potential for chemical EOR flooding applications. The results demonstrated that an alternate injection of a 1.3 CMC biosurfactant solution and 3 wt% brine should be able to permeate through the porous media, migrate to the water/oil interface, reduce the interfacial tension (IFT), and increase the oil recovery factor by 13%. In additional, a core flood experiment was performed to study the impact of this MEOR injection on the rock properties.

Characterization and Initial Application of Endophytic Bacillus safensis Strain ZY16 for Improving Phytoremediation of Oil-Contaminated Saline Soils.

Hydrocarbon-degrading and plant-growth-promoting bacterial endophytes have proven useful for facilitating the phytoremediation of petroleum-contaminated soils with high salinity. In this study, we identified Bacillus safensis strain ZY16 as an endophytic bacterium that can degrade hydrocarbons, produce biosurfactants, tolerate salt, and promote plant growth. The strain was isolated from the root of Chloris virgata Sw., a halotolerant plant collected from the Yellow River Delta. ZY16 survived in Luria-Bertani (LB) broth with 0–16% (w/v) sodium chloride (NaCl) and grew well in LB broth supplemented with 0–8% NaCl, indicating its high salt tolerance. The endophytic strain ZY16 effectively degraded C12–C32 n-alkanes of diesel oil effectively, as well as common polycyclic aromatic hydrocarbons under hypersaline conditions. For example, in mineral salts (MS) liquid medium supplemented with 6% NaCl, ZY16 degraded n-undecane, n-hexadecane, n-octacosane, naphthalene, phenanthrene, and pyrene, with degradation percentages of 94.5, 98.2, 64.8, 72.1, 59.4, and 27.6%, respectively. In addition, ZY16 produced biosurfactant, as confirmed by the oil spreading technique, surface tension detection, and emulsification of para-xylene and paraffin. The biosurfactant production ability of ZY16 under hypersaline conditions was also determined. Moreover, ZY16 showed plant-growth-promoting attributes, such as siderophore and indole-3-acetic acid production, as well as phosphate solubilization. To assess the enhanced phytoremediation of saline soils polluted by hydrocarbons and the plant-growth-promotion ability of ZY16, a pot trial with and without inoculation of the endophyte was designed and performed. Inoculated and non-inoculated plantlets of C. virgata Sw. were grown in oil-polluted saline soil, with oil and salt contents of 10462 mg/kg and 0.51%, respectively. After 120 days of growth, significant enhancement of both the aerial and underground biomass of ZY16-inoculated plants was observed. The soil total petroleum hydrocarbon degradation percentage (a metric of phytoremediation) after incubation with ZY16 was 63.2%, representing an elevation of 25.7% over phytoremediation without ZY16 inoculation. Our study should promote the application of endophytic B. safensis ZY16 in phytoremediation by extending our understanding of the mutualistic interactions between endophytes and their host plants.

Chemical Profiling and Biological Screening of Some River Nile Derived-Microorganisms.

AimsChemical and biological studies of the River Nile derived-microorganisms are limited. Hence, this work was carried out to screen the River Nile habitat. Identification of the isolated organisms, chemical profiling of their ethyl acetate extracts as well as screening of their antimicrobial, antileishmanial, antitrypanosomal, and antimalarial activities were investigated.MethodsIdentification of the microbial isolates were carried out using bacterial 16S rRNA and fungal 18S rRNA gene sequencing. Chemical profiling of the EtOAc extracts using LC-HRESIMS spectroscopy was carried out. The in vitro antimicrobial screening using the modified version of the CLSI method, antileishmanial and antitrypanosomal activities were screened using Leishmania donovani promastigote assay, L. donovani axenic amastigote assay, Trypanosoma brucei trypamastigotes assay and THP1 toxicity assay. The in vitro antimalarial activities against D6 (chloroquine sensitive) and W2 (chloroquine-resistant) strains of Plasmodium falciparum were evaluated.ResultsSeven isolated microorganisms were identified as Streptomyces indiaensis, Bacillus safensis, B. anthracis, Bacillus sp., and Aspergillus awamori. Chemical investigation of different extracts showed several bioactive compounds, identified as; nigragillin, 5-caboxybenzofuran and dyramide B from A. awamori and actinopolysporin B from S. indiaensis. On the other hand many nitrogenous compounds with high molecular weights showed no hits that may correspond to new long chain and/or cyclic peptides. The EtOAc extract of B. safensis fermentation broth showed the highest activity against P. falciparum D6 and P. falciparum W2 (IC50 = 25.94 and 27.28 μg/mL, respectively), while two isolates S. indiaensis and Bacillus sp. RN-011 extracts showed the highest antitrypanosomal activity (IC50 = 0.8 and 0.96 μg/mL).ConclusionThe River Nile could be a new source for production of promising bioactive leading compound where antimicrobial and antiparasitic activities may be correlated.

An innovative biotransformation to produce resveratrol by Bacillus safensis.

Resveratrol is considered as a potential food supplement, cosmetic ingredient and nutraceutical. In this study, resveratrol was produced by biotransformation successfully. In detail, a β-glucosidase producing strain was isolated and identified as Bacillus safensis, and it could convert polydatin to resveratrol efficiently and rapidly. Further research showed that the conversion rate to resveratrol reached 93.1% in 8 h at 37 °C. The production of resveratrol was confirmed by HPLC, LC-MS and 1H-NMR to identify its structure and it was verified to possess antibacterial properties especially against Escherchia coli. To illustrate the resveratrol transformation mechanism, several glucosidases from B. safensis CGMCC 13129 were expressed and analyzed. The results showed that BGL4 and BGL5 had higher transformation activity compared with other tested glucosidases. This research provides a novel approach to produce resveratrol, and would promote the application of resveratrol in health-promoting pharmaceutical and food products.

Phân lập, tuyển chọn và định danh các chủng vi khuẩn đối kháng trong đất có khả năng phòng trị bệnh thối củ hành tím do vi khuẩn Pseudomonas aeruginosa

Soft rot caused by Pseudomonas aeruginosa is one of the most destructive diseases of shallot in Vĩnh Châu district, Sóc Trăng proivince. This study aims at isolating, testing for disease-reducing effects and identifying the antagonistic soil bacteria against the disease. Among the 133 bacterial isolates obtained from shallot fields of Vĩnh Châu, four isolates 2C, 3A, 3B and 4A exhibited their antagonistic effects against the pathogen. The isolate 3B was the strongest antagonist among those tested (inhibition zone radii = 6 mm). Using cell-free suspensions, that of the isolate 4A performed the strongest inhibition (inhibition zone radii = 6 mm). Under greenhouse conditions, seed soaking using 108 CFU/mL suspensions of the isolates 3B and 4A and soil drenching using 109 CFU/mL suspension of 3B and 108 CFU/mL suspension of 4A showed strong disease-reducing effects until 12 days after inoculation. Based on the 16S rRNA gene sequences combined with the morphological and biochemical characteristics of the bacterial strains, 3B was identified as Bacillus safensis and 4A as Bacillus stratosphericus.

Reduction of hexavalent chromium by Bacillus spp. isolated from heavy metals-polluted soil

Hexavalent chromium, Cr(VI), one of the major pollutants from industrial facilities, is very toxic and harmful for human health and environmental quality. Due to the lack of conventional methods, bioremediation was recommended as an environmentally friendly and effective technique. The aim of this paper was the isolation, identification and selection of the microorganisms which are capable of Cr(VI) reduction in vitro. Heavy metal concentration, detected in four soil samples, within and around the former bicycle factory ?Rog? (Republic of Slovenia), was measured using the ICP-OES method. Bacteria were isolated and tested for chromium tolerance using LB agar supplemented with various Cr(VI) concentrations, whilst Cr(VI) reduction and bacterial growth was determined using the LB liquid medium. From 53 bacterial isolates, five of them showed a tolerance of 1000 mg/L of Cr(VI). Those five isolates showed the capability of growth under various Cr(VI) concentrations (50-1000 mg/L). Initial Cr(VI) concentrations ranging from 50 to 100 mg/L were completely reduced by four bacterial isolates, whilst 500 to 1000 mg/L by Bacillus safensis 342-9. Using 16S rDNA and tuf gene sequence analyses, isolates 270-9R and 342-9 were identified as Bacillus safensis, isolates 351-9 and 270-9C as Bacillus subtilis subsp. subtilis, and 212-9 as Bacillus thuringiensis. These results indicated that these bacteria may be promising tools for remediation of metal-polluted sites.

Antibacterial, anti-adherent and cytotoxic activities of surfactin(s) from a lipolytic strain Bacillus safensis F4.

The bacterial strain F4, isolated from olive oil-contaminated soil, has been found to produce biosurfactants as confirmed by oil displacement test and the emulsification index results. The identification of the strain F4, by 16S ribosomal RNA gene, showed a close similarity to Bacillus safensis, therefore the strain has been termed Bacillus safensis F4. The Thin Layer Chromatography (TLC) and the High Pressure Liquid Chromatography-Mass Spectrometry (HPLC-MS/MS) demonstrated that the biosurfactant had a lipopeptide structure and was classified as surfactin. The present study showed also that the produced biosurfactant has an important antibacterial activity against several pathogen strains as monitored with minimum inhibitory concentration (MIC) micro-assays. In particular, it presented an interesting anti-planktonic activity with a MIC of 6.25mgmL-1 and anti-adhesive activity which exceeded 80% against the biofilm-forming Staphylococcus epidermidis S61 strain. Moreover, the produced lipopeptide showed an antitumor activity against T47D breast cancer cells and B16F10 mouse melanoma cells with IC50 of 0.66mgmL-1 and 1.17mgmL-1, respectively. Thus, our results demonstrated that Bacillus safensis F4 biosurfactant exhibited a polyvalent activity via a considerable antibiofilm and antitumoral potencies.

Preliminary report on the study of postharvest fruit rot bacteria and yeasts in Lanzhou Lily (Lilium davidii var. unicolor) in China

AbstractFruit rot is one of the most important factors affecting the postharvest quality and shelf life of Lanzhou Lily fruits. The aims of this study were to characterize different isolates from Lanzhou Lily using morphological and molecular approaches and to test their pathogenicity in Lanzhou Lily fruit. Different isolates were collected from decayed Lanzhou Lily fruits in Lanzhou in Gansu Province in China during 2016 and 2017. In total, four isolates were obtained and identified based on their DNA sequences of the 16S rDNA and 26S rDNA genes in combination with the morphological characteristics of the cultures and sporulation. Of the four isolates, one was identified as Bacillus safensis, one was Stenotrophomonas maltophilia and the other two isolates were Metschnikowia pulcherrima. The pathogenicity tests showed that all four isolates were pathogenic in Lanzhou Lily fruit. Previously Fusarium tricinctum has been reported to be the primary cause of fruit rot in Lanzhou Lily throughout the world. Our report is the first to show results that indicate that B. safensis, S. maltophilia and M. pulcherrima are pathogenic in Lanzhou Lily in China. This is the first report on the bacteria and yeast that infect Lanzhou Lily fruits.

Biotransformation of eugenol to vanillin by a novel strain Bacillus safensis SMS1003

Due to the extensive applications of vanillin as flavored compound and increasing consumers concern for its natural and environment friendly mode of production, present work was focused on the selection of bacterial isolate capable of producing vanillin using eugenol biotransformation. Bacterial strain SMS1003 is evidenced as the potential strain for vanillin production and identified as Bacillus safensis (GeneBank accession no. MG561863) using biochemical tests and molecular phylogenic analysis of its 16S rDNA gene sequence. Molar yield of vanillin reached up to 10.7% (0.055 g/L) at 96 h of biotransformation using growing culture of B. safensis SMS1003 in following culture conditions: eugenol concentration 500 mg/L; temperature 37 °C; initial pH 7.0; inoculum volume 4%; volume of culture media 10%; and shaking speed 180 rpm. Vanillin was detected as the single metabolite with a molar yield of 26% (0.12 g/L) at 96 h using resting cells of B. safensis SMS1003. Product confirmation was based on spectral scan using photodiode array detector, Fourier-transform infrared spectroscopy, high-performance liquid chromatography, and mass spectroscopy.

Bacillus safensis subsp. osmophilus subsp. nov., isolated from condensed milk, and description of Bacillus safensis subsp. safensis subsp. nov.

A bacterial strain, designated BC09T, was isolated from a contaminated sample of condensed milk. Phylogenetic analyses based on 16S rRNA gene sequences placed strain BC09T into the genus Bacillus with its closest relatives being Bacillus safensis and Bacillus australimaris with 100 and 99.9 % similarity, respectively. Analysis of the gyrB gene confirmed the closeness of strain BC09T with respect to the species B. safensis since it presented 97.8 and 95.2 % similarity values, respectively, to the type strains of B. safensis and B. australimaris. DNA-DNA hybridization confirmed these results showing averages of 67 and 56 %, respectively, between strain BC09T and the type strains of B. safensis and B. australimaris. Average nucleotide identity blast values obtained for BC09T compared to the closest relative type strains were 95.7 and 67.6 %, respectively, and predicted DNA-DNA hybridization values were 93.1 and 51.9 %, respectively. However, strain BC09T differs from the type strains of its closest relatives in several phenotypic characteristics. MK-7 was the only menaquinone detected and iso-C15:0 and anteiso-C15:0 were the major fatty acids. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, two unidentified phospholipids, two unidentifed glycolipids, three unidentified lipids and one unidentifed phosphoglycolipid. Meso-diaminopimelic acid was detected in the peptidoglycan. The G+C content was 40.9 mol%. Phylogenetic, chemotaxonomic and phenotypic analyses showed that strain BC09T represents a new subspecies of B. safensis, for which the name Bacillus safensis subsp. osmophilus subsp. nov. is proposed. The type strain is BC09T (=LMG 30124T, =CECT 9344T).

Optimizing the metribuzin degrading potential of a novel bacterial consortium based on Taguchi design of experiment.

Metribuzin (MB) is used for control of weeds in crops like potato, maize and sugarcane. Its extensive and unjudicial use has resulted in various environmental issues; hence it is very critical to remediate this herbicide at the respective point source. Plant associated, MB degrading bacterial strains, Rhodococcus rhodochrous sp. AQ1, Bacillus tequilensis sp. AQ2, Bacillus aryabhattai sp. AQ3 and Bacillus safensis sp. AQ4 were isolated, and a consortium MB3R was developed. For degradation of MB by the consortium MB3R, various parameters i.e., pH, temperature, inoculum density and pesticide concentration were optimized by using Taguchi design of experiment (DOE). MB degradation was dependent upon all the four factors. The contribution of each factor on MB degradation was according to the order: temperature > inoculum density > pH > pesticide concentration. Fitness of Taguchi DOE in forecasting the optimum response, was confirmed experimentally by using optimized levels of the four factors i.e., pH 7.0, temperature 30 °C, pesticide concentration 45 mg l-1 and an inoculum density of 5.0 × 10 5 CFU ml-1 whereby 98.63% MB degradation was observed. Appearance and subsequent degradation of three MB metabolites, desamino-metribuzin (DA), diketo-metribuzin (DK) and desamino-diketo-metribuzin (DADK) during biodegradation by the consortium was observed.

A multi-strain probiotic administered via drinking water enhances feed conversion efficiency and meat quality traits in indigenous chickens.

Whereas the use of probiotics is commonplace in commercial production of improved chicken strains, little is known about the impact of these live microbial feed additives in indigenous chickens in South Africa. This study investigated the effect of a multi-strain probiotic (containing Bacillus safensis, Bacillus subtilis, Bacillus megaterium and Cupriavidus metallidurans, total bacteria number was 1.4 × 108 cfu/mL), administered via drinking water, on growth performance, blood parameters, and carcass and meat quality characteristics of Potchefstroom koekoek cockerels for a period of 12 weeks. A total of 140 five-week-old cockerels were randomly allocated to 4 experimental diets formulated to have similar energy and protein levels as follows: 1) negative control diet (CON; commercial chicken grower diet without both antibiotics and probiotics), 2) positive control diet (ANTIB; commercial chicken grower diet with antibiotics [0.05% Coxistac and 0.04% olaquindox] but no probiotics), 3) negative control diet plus 2.5 mL of probiotics per litre of water (PROB25) and 4) negative control with 5.0 mL of probiotics per litre of water (PROB50). There was a significant (P < 0.05) week and diet interaction effect on average weekly feed conversion efficiency. At 9 weeks of age, cockerels in PROB50 group had higher (P < 0.05) feed conversion efficiency than those in CON and ANTIB groups. However, 14-week-old cockerels in PROB50 group had lower (P < 0.05) feed conversion efficiency than those in ANTIB group. Treatments had no significant (P > 0.05) effect on overall feed intake, overall weight gain and haemato–biochemical parameters of cockerels. Gizzard and spleen weights were similar (P > 0.05) in PROB50, CON and PROB25 groups. Cockerels in PROB50 group had shorter (P < 0.05) small intestine than those in CON and PROB25 groups. Cockerels in PROB50 group had larger (P < 0.05) breast weight than those in PROB25 group. Cockerels in ANTIB and PROB50 groups had greater (P < 0.05) wing and thigh weights than those in CON and PROB25 groups. Shank weight was similar (P > 0.05) in PROB50, CON and ANTIB groups. Meat pH measured after 24 h of slaughter was the highest (P < 0.05) in CON and ANTIB groups followed by PROBO25 and PROB50 groups. Cockerels in CON group had lower (P < 0.05) cooking losses than those in ANTIB, PROB25 and PROB50 groups. It was concluded that probiotics can be used in place of prophylactic antibiotics in Potchefstroom koekoek cockerels.

English

Strains previously isolated from offshore oil reservoirs in Campos Basin (RJ, Brazil) and Potiguar Basin (RN, Brazil) were tested for production of antimicrobial compounds. Sixteen bacteria produced compounds with antimicrobial activity. The strain chosen for further study was Bacillus safensis SG-32 based on its ability to inhibit 76% of the strains tested. The bacterium was grown in Marine Broth (MB) and the hexane extract was investigated for minimal inhibitory concentration (MIC) (highest activity 0.4 mg/mL against Staphylococcus aureus), antiproliferative activity against human cancer cell lines (highest activity TGI = 69.83 µg/mL against melanoma cell lines), and antiparasitic tests (maximum activity 22.49% against Trypanosoma cruzi). Bioactive extract from B. safensis SG-32 was purified using silica column chromatography. Fractions collected were tested by bioautography in order to select the fraction with antimicrobial activity. The active molecule was identified by Nuclear Magnetic Resonance (NMR) as a diterpene of the Cyathin family. In addition to the antimicrobial and antitumor activity, Cyathin type compounds are known to stimulate the synthesis of Nerve Growth Factor (NGF), a capacity that implicates their potential as therapeutic agents to treat neurodegenerative ailments such as Alzheimer’s or Parkinson’s disease. In conclusion, this study showed that B. safensis SG-32 produces metabolites with antibacterial, antiproliferative and antiparasitic activities, and opens perspectives for further study of its potential also for nerve protection. Key words: Antimicrobial, antiproliferative, Bacillus safensis, Cyathin, nerve grow factor, drug discovery.

Draft Genome Sequence of Bacillus safensis Strain JG-B5T, Isolated from a Uranium Mining Waste Pile.

Bacillus safensis strain JG-B5T was isolated from soil of the uranium mining waste pile Haberland located near Johanngeorgenstadt, Saxony, Germany. We report here a draft genome sequence (3.7 Mb) of this bacterial strain. The high metal resistance abilities of B. safensis strain JG-B5T can be exploited for bioremediation of metal and metalloid-contaminated environments.

Non-halophilic endophytes associated with the euhalophyte Arthrocnemum macrostachyum and their plant growth promoting activity potential.

Numerous microbial taxa establish natural relations with plants, and especially endophytes can be relevant in the development and growth promotion of their host. In this work, we explore the diversity of non-halophilic microorganisms inhabiting the endosphere of the halophyte Arthrocnemum macrostachyum. A total of 1045 isolates were recovered using standard non-saline media, which clustered into 22 operational phylogenetic units (OPUs) including 7 putative new species and 13 OPUs not previously detected as endophytes. The more abundant isolates corresponded to close relatives of Kushneria indalinina/K. marisflavi, Providencia rettgeri, Pseudomonas zhaodongensis and Bacillus safensis, which made up to ∼ 62% of the total isolates. We also isolated OPUs not detected by the culture-independent approach reinforcing the need of culturing to reveal the microbial diversity associated with plants. Additionally, the plant growth promoting activity was evaluated by representative strains of the more abundant OPUs (total=94 strains) including also some previously isolated halophiles from the same plants. Under both saline and non-saline conditions, some strains principally those affiliated to Paenibacillus borealis, Staphylococcus equorum, Salinicola halophilus and Marinococcus tarijensis, presented growth promoting activity in Arabidopsis thaliana, which was evaluated as an increment of weight and root length.