Search

Copyright of Revista Colombiana de Ciencias Hortícolas is the property of Revista Colombiana de Ciencias Horticolas and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Graphical abstract Highlights • B. mycoides strain R2 produced styrene to repel and kill the root-knot nematode. • Styrene is reported as a nematode repellent for potential development of novel nematicides. • AWB neuron and signal transduction pathways cGMP-CNG and PLC-TRPV were involved in sensing styrene. Abstract Root-knot nematodes are obligate parasites that feed on plant roots and cause serious crop losses worldwide. Bacillus species (Bacilliaceae) can produce nematicidal metabolites and have shown good potential for biological control of nematodes. In this study, Bacillus mycoides strain R2 isolated from rhizosphere soil of tomato plants exhibited high nematicidal activity against the free-living nematode Caenorhabditis elegans and the root-knot nematode Meloidogyne incognita. In a pot experiment, control efficiency of B. mycoides R2 on M. incognita was as high as 90.94%. The nematicidal compound was isolated and identified as styrene. The median lethal concentration of styrene against M. incognita was 4.55 μg/ml (m/v). The volatile styrene caused avoidance and killed nematodes primarily by the olfactory neuron and G protein signal pathway. C. elegans detected styrene with the AWB neuron; the signal was then transmitted to the downstream G protein coupled receptors CHE-3, DOP-3, and STR-2. Then signal activated G protein GPA-3 and GPA-7. The signal was then transmitted to ion channels (CNGs channel and TRPV channel), causing calcium ion internal flow and a stress response towards the increased concentration of intracellular calcium. Styrene should be registered as a nematode repellent and biocontrol agent for protection of crops against root-knot nematode attack. [ABSTRACT FROM AUTHOR]

High-glucose syrup has wide applications in the feed and fermentation industries. However, during its regular production process, because of the slow hydrolysis of a-1,6-glucosidic linkages in maltodextrins by glucoamylase, yields of glucose higher than 96% are rarely achieved. To find a suitable enzyme for the saccharification process, two novel genes encoding oligo-1,6-glucosidases (OGL, EC 3.2.1.10) from Bacillus mycoides (bmogl) and Thermomyces lanuginosus (tlogl) were successfully cloned and overexpressed in Pichia pastoris GS115. At the shake-flask fermentation level, the OGL activities of the two recombinants GS115 (pPIC9Kbmogl) and GS115 (pPIC9K-tlogl) were 994 and 1219U/mL, respectively; and mature enzymes around 66-68 kDa were purified for characterization. Recombinant enzyme TlOGL exhibited higher thermostability than ever reported for OGLs, whereas BmOGL was stable under acidic pH, ranging from 4.0 to 8.0. Among the substrates tested, these two recombinant enzymes efficiently hydrolyzed isomaltose and isomaltotriose, but had no activity against maltose and maltotriose. Besides these characteristics, nearly complete hydrolysis of isomaltotriose and 90% of isomaltooligosaccharides (IMOs) into glucose was also observed for them, which makes them good candidates for subsequent use in improving the yield of glucose from starch. To the best of our knowledge, this is the first report on the expression and characterization of OGLs from B. mycoides and T. lanuginosus. [ABSTRACT FROM AUTHOR]

Ulcerative disease causes significant economic losses in largemouth bass Micropterus salmoides production. Yet information reported on Bacillus mycoides as a pathogen for largemouth bass is scarce. In this study, a virulent strain, temporarily named LYS1, was isolated from diseased M. salmoides suffering from ulcerative disease, identified phenotypically and molecularly as B. mycoides. A phylogenetic tree was constructed to examine isolate LYS1 and compare it to other known isolates. In addition, isolate LYS1 appears to be susceptible to aminoglycosides and quinolones drugs for veterinary use in aquaculture as seen when screened against a range of common antibiotics. To the best of our knowledge, this is the first report of B. mycoides as a pathogen of ulcerative disease in farmed largemouth bass. [ABSTRACT FROM AUTHOR]

The aim of this research was to evaluate changes to several chemical, biological and physical properties of a Salidic Calciustolls, in response to enhancement by treatment with low rank coal (LRC) and coal solubilizing bacteria (CSB) - Bacillus mycoides, Microbacterium sp and Acinetobacter baumannii- that release humified organic matter (HOM) through biotransformation of the coal. Under field conditions, 5 m 2 plots were treated with the addition of LRC at a dose of 5 kg m 2 and an inoculum of CSB in a suspension of 1x10 8 bacteria mL -1 at a dose of 100 mL m -2 . Soil respiration, microbiological activity, lignin peroxidase (LiP), manganese peroxidase (MnP) and laccase (Lac) enzyme activities were quantified. The variables associated with saline-sodic soils - pH, electrical conductivity (EC), sodium adsorption ratio (SAR), exchangeable sodium percentage (ESP), cation exchange capacity (CEC) were measured every two months bulk density (BD) was determined sixth months after the start of the experiment. The LRC application contributed to the decrease of EC, SAR and ESP, but pH levels did not change significantly. Additionally, no significant changes were found in the BD, however the treatment increased the respiration and microbiological activity of soil, stimulated LiP, MnP and Lac enzyme activity, and increased soil CEC. These results suggest the possibility of using the LRC as an HOM source for the rehabilitation of degraded saline soils - a common problem in soils of the Cesar River Valley (Colombia) and in the dry lands of the Colombian Caribbean influenced by open-pit coal mining. [ABSTRACT FROM AUTHOR]

Plant root secreted compounds alter the gene expression of associated microorganisms by acting as signal molecules that either stimulate or repel the interaction with beneficial or harmful species, respectively. However, it is still unclear whether two distinct groups of beneficial bacteria, non-plant-associated (soil) strains and plantassociated (endophytic) strains, respond uniformly or variably to the exposure with root exudates. Therefore, Bacillus mycoides, a potential biocontrol agent and plant growth-promoting bacterium, was isolated from the endosphere of potatoes and from soil of the same geographical region. Confocal fluorescence microscopy of plants inoculated with GFP-tagged B. mycoides strains showed that the endosphere isolate EC18 had a stronger plant colonization ability and competed more successfully for the colonization sites than the soil isolate SB8. To dissect these phenotypic differences, the genomes of the two strains were sequenced and the transcriptome response to potato root exudates was compared. The global transcriptome profiles evidenced that the endophytic isolate responded more pronounced than the soil-derived isolate and a higher number of significant differentially expressed genes were detected. Both isolates responded with the alteration of expression of an overlapping set of genes, which had previously been reported to be involved in plant-microbe interactions; including organic substance metabolism, oxidative reduction, and transmembrane transport. Notably, several genes were specifically upregulated in the endosphere isolate EC18, while being oppositely downregulated in the soil isolate SB8. These genes mainly encoded membrane proteins, transcriptional regulators or were involved in amino acid metabolism and biosynthesis. By contrast, several genes upregulated in the soil isolate SB8 and downregulated in the endosphere isolate EC18 were related to sugar transport, which might coincide with the different nutrient availability in the two environments. Altogether, the presented transcriptome profiles provide highly improved insights into the life strategies of plant-associated endophytes and soil isolates of B. mycoides. [ABSTRACT FROM AUTHOR]

The present feeding trial examined the effect of synbiotic use of Bacillus mycoides and organic selenium ( OS) as Sel-Plex on marron immunity, growth and survival. The marron were cultured in recirculated tanks and fed test diets consisting of a basal diet; basal diet supplemented with B. mycoides (108 CFU g−1 of feed); basal diet supplemented with OS (Sel-Plex) (0.2 g kg −1 of feed) and basal diet supplemented with synbiotic ( B. mycoides at 108 CFU g−1 and OS 0.2 g kg −1 feed) diet, in triplicate. The effect of the prebiotic OS (Sel-Plex) on the growth rate of B. mycoides was also studied in vitro. The results suggested that synbiotic use of B. mycoides and OS significantly improved some immune parameters of marron, particularly the glutathione peroxidase, and to some extent total haemocyte counts. However, the synbiotic feed did not synergistically improve marron growth, in fact the use of B. mycoides-supplemented diet alone demonstrated significantly higher growth in marron compared with the growth of marron fed on other test diets. Supplementation of the basal diet with host origin B. mycoides significantly increased the intestinal bacterial population (3.399 ± 825 CFU g −1 of gut) in marron compared with other diets. Organic selenium as Sel-Plex in Trypticase Soya Broth also confirmed that OS did not increase the amount of growth of B. mycoides and resulted in a lower intestinal bacterial population in the synbiotic diet-fed marron. In conclusion, synbiotic of OS and B. mycoides may improve a particular immune parameters of marron and to a lesser extent their growth. [ABSTRACT FROM AUTHOR]

In order to develop a method for electroporation of environmental Bacillus mycoides strains, we optimized several conditions that affect the electroporation efficiency of this bacterium. By combining the optimized conditions, the electroporation efficiency of strain EC18 was improved to (1.3 ± 0.6) × 10 5 cfu/μg DNA, which is about 10 3 -fold increase in comparison with a previously reported value. The method was further validated on various B. mycoides strains, yielding reasonable transformation efficiencies. Furthermore, we confirmed that restriction/modification is the main barrier for electroporation of this bacterium. To the best of our knowledge, this is the first systematic investigation of various parameters of electroporation of B. mycoides . The electroporation method reported will allow for efficient genetic manipulation of this bacterium. [ABSTRACT FROM AUTHOR]

Microbial enzymes are known to be superior to enzymes obtained from other organisms, particularly for applications in industries on commercial scales. The species of the genus Bacillus are known to be producers of enzymes of industrial interest. Among them, amylolytic enzymes have got great biotechnological applications and economic exploitations. Amylases are known to be produced by a variety of bacteria and fungi and their applications at industrial level have stimulated interest to explore their amylolytic activity in several microbes to be used as bioresources. A newly soil-isolate, identified as a Bacillus mycoides strain, was tested for its ability to produce extracellular amylase in liquid media, using multiple carbon sources and starchy substrates. Chip electrophoresis was used to obtain the electrophoretic profile of proteins derived from the bacterial isolate and a molecular weight of 60 kDa, characteristic for amylase produced by Bacillus genus, was obtained in two experimental media. Bioprocess optimization was designed using L9 and L16 Taguchi orthogonal arrays and analyzed by ANOVA statistical methods. A maximum enzymatic activity (10.44 U/ml) was determined when malt extract and ammonium sulphate, as starchy substrate and nitrogen source, were used. Optimum growth conditions were identified to be 32°C, 220 rpm and 48 hrs fermentation time, while the inoculation volume was 2%. A positive effect for amylase production was observed for citric acid and CaCl2 interaction in the culture media. [ABSTRACT FROM AUTHOR]

Most of the plant diseases are caused by microorganisms. Among these, most often mentioned in the literature are bacteria and fungi. Diseases caused by phytopathogens like Erwinia carotovora and Xanthomonas campestris lead to lower production and quality, causing significant economic losses. In order to prevent the diseases can be used microbial antagonists which, besides protection capability, can stimulate plant growth by degrading the substrate and releasing of certain compounds needed for growth. After a preliminary screening, from a total of 25 microorganisms isolated from plant materials, best antimicrobial activities were registered with bacteria B1 and Bm belonging to the genera Pseudomonas sp. respectively Bacillus sp.. Following biochemical tests in conjunction with microscopy studies and MALDI-TOF MS, selected bacteria were identified as Pseudomonas putida, respectively Bacillus mycoides. Their antimicrobial activity was comparable to that of microorganisms belonging to the same genera, from the collection of the National Institute for Chemical Pharmaceutical Research and Development-ICCF. When they were grown on agar media with different compositions, significant differences regarding antimicrobial activity have not been observed. However, substantial differences were recorded in terms of antagonistic ability between Pseudomonas putida and Bacillus mycoides, the last one making the biggest area of inhibition against both phytopathoges X. campestris ICCF 274 (40 mm) and E. carotovora ICCF 138 (20 mm). These results suggest the possibility of using newly isolated antagonists to prevent diseases caused by Erwinia carotovora and Xanthomonas campestris. [ABSTRACT FROM AUTHOR]

A novel application of whole cells of Nocardia corallina B-276 for the deracemisation of ibuprofen is reported. This microorganism successfully hydrolysed ibuprofen nitrile to ibuprofen amide, and ibuprofen amide to ibuprofen, using a suspension of cells in a potassium phosphate buffer solution (0.1 M, pH = 7.0). These results can be explained by the presence of NHase and amidase enzymes, but the reactions are not enantioselective and low ee values were obtained. However, (R)-ibuprofen was isolated with >99% ee by a deracemisation process catalysed by N. corallina B-276. This is the first report of this kind of catalysis with this microorganism.

The microfiltration (MF) of high solids content gum Arabic solutions (15 wt%) inoculated with Bacillus mycoides spores (105 CFU ml-1) was carried out using Membralox tubular ceramic membranes with a nominal pore size of 0.8 μm. Consistent permeate fluxes were achievable over multiple fouling and cleaning cycles, while giving low rejection of solids and high rejection of spores (after ten cycles, a permeate flux of 42.9Lm-2 h-1, a solids retention of 19.8%, and a spore rejection of 5.0 log orders were achieved). Although fouling during filtration was severe, permeate fluxes could be restored to a satisfactory condition after cleaning with 0.5 wt% NaOH solution containing 200 ppm NaOCl. Results were described by a two species first order removal model, whereby one species was removed quickly by cleaning and the other was more difficult to remove. The optimum cleaning time for NaOH + NaOCl solutions at 60 °C was found to be ca. 20 min. Subsequent citric acid cleans had a negative effect upon restoring permeate flux. [ABSTRACT FROM AUTHOR]

This research was performed to characterize the resistance of three different bacterial spore species isolated from pasteurized edible crab ( Cancer pagurus ) meat to heat treatments and to assess the potential of manosonication (MS) and manothermosonication (MTS) as an alternative for their inactivation. The spore-forming bacteria used in this study were Bacillus mycoides , Bacillus weihenstephanensis and Psychrobacillus psychrodurans . The thermal resistance of these three species was determined at different temperatures ranging from 80 to 110 °C and their resistance to ultrasound under pressure from 35 to 95 °C. Ginafit Excel tool was used to fit the Geeraerd's ‘Log-linear + shoulder’ and Bigelow & Easty's equations to the survival curves for heat and MS/MTS treatments. From the results obtained it can be concluded that the profile of the survival curves either for heat or for ultrasound treatments depended on the bacterial spore species. When shoulders were detected in the inactivation curves for heat they were also present in the curves for MS/MTS treatments, although the application of an ultrasonic field reduced the shoulder length. B. weihenstephanensis was found to be the most resistant species to heat, requiring 1.4 min to reduce 4 log 10 cycles at 107.5 °C ( z T = 7.1 °C) while B. mycoides was the most sensitive requiring 1.6 min at 95 °C ( z T = 9.1 °C). By contrast, B. mycoides was the most resistant to MS. The efficiency of the combination of ultrasonic waves under pressure with heat (MTS) for bacterial spore inactivation was directly correlated with the thermal resistance. Indeed, MTS showed a synergistic effect for the inactivation of the three spores. The highest percentage of synergism corresponded to the spore species with higher z T value ( B. mycoides ), but the highest temperature at which this synergism was detected corresponded to the most heat tolerant spore species ( B. weihenstephanensis ). This study revealed that MTS treatment is capable of inactivating spore-forming bacteria and that the inactivation efficiency of the combined treatment is correlated with the thermal resistance of the spore species. [ABSTRACT FROM AUTHOR]

The nitrogen fixation by strains belonging to the Bacillus genus remains poorly explored. In this work, the diversity of endospore-forming bacilli isolated from the rhizosphere of sunflower was evaluated. A total of 101 strains were identified based on the V1-V2 variable regions of the 16S rRNA gene. Strains belonging to the genera Bacillus and Paenibacillus represented 41.6 % and 58.4%, respectively, of total isolates. The production of indolic compounds was a common trait among the isolates, and approximately 75% of them exhibited positive nitrogenase activity; but only 9.2% displayed activities higher than 1 nmol C2H4 mg protein h-1. Within the genus Bacillus, the isolates related to the B. cereus group displayed the highest nitrogenase activity and were the second most frequent group of Bacillus sp. isolated. Plants inoculated with the isolate B38V showed the highest N content, and their shoot dry weights were significantly increased compared with positive control. Our results indicated that B38V, which belongs to the B. mycoides species, has the potential to promote sunflower growth. The data obtained in this study provide additional information concerning the diversity of Gram-positive diazotrophic within the genera Bacillus and Paenibacillus and their potential for the biofertilisation of sunflower crops. [ABSTRACT FROM AUTHOR]

Biosurfactant production from two indigenous consortia has already been investigated in two previous studies. In this study, comparison and modification of those models for having as much biosurfactant as possible was conducted. After characterization of bacteria by biochemical tests and 16S ribotyping, a fully modification on the final models was presented. Response surface methodology has the ability to investigate the liability of the parameters and models by the help of Desirability mode and R 2 coefficient in Design Expert software. Our models in the previous works follow the style of ( y = f ( A , B ,…)) and two Desirability of 0.968 and 0.996 for Paenibacillus alvei ARN63 and Bacillus mycoides SH2, respectively. After modification by the help of Cox–Box tools in the software, two new models were in the forms of ( y 3 = f 1 ( A , B ,…)) and ( y 0.57 = f 2 ( A , B ,…)) and their Desirability were 1 and 0.988, respectively which are much more reliable than the previous ones. These new models present a higher R 2 and precision comparing to the non-modified data and models. Analysis of variance for both consortia showed the independency of P. alvei ARN63 from temperature and B. mycoides SH2 from lonely variations of pH and salinity. Finally, the effect of this modification has examined on enhancing oil recovery by produced biosurfactants. The results show that the modified model obtained in this study has significant role in modes of enhancing bacterial efficiency for surfactant enhanced oil recovery. [ABSTRACT FROM AUTHOR]

In this contribution a new method for improving the accuracy of classification and identification experiments is presented. For this purpose the four most applied dimension reduction methods (principal component analysis, independent component analysis, partial least square dimension reduction and the linear discriminant analysis) are used as starting point for the optimization method. The optimization is done by a specially designed genetic algorithm, which is best suited for this kind of experiments. The presented multi-level chemometric approach has been tested for a Raman dataset containing over 2200 Raman spectra of eight classes of bacteria species ( Bacillus anthracis, Bacillus cereus, Bacillus licheniformis, Bacillus mycoides, Bacillus subtilis, Bacillus thuringiensis, Bacillus weihenstephanensis and Paenibacillus polymyxa). The optimization of the dimension reduction improved the accuracy for classification by 6% compared with the accuracy, if the standard dimension reduction is applied. The identification rate is improved by 14% compared with the dimension reduction. The testing in a classification and identification experiment showed the robustness of the algorithm. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Background One of the major challenges of nanotechnology during the last decade has been the development of new procedures to synthesize nanoparticles. In this context, biosynthetic methods have taken hold since they are simple, safe and eco-friendly. Results In this study, we report the biosynthesis of TiO2 nanoparticles by an environmental isolate of Bacillus mycoides, a poorly described Gram-positive bacterium able to form colonies with novel morphologies. This isolate was able to produce TiO2 nanoparticles at 37°C in the presence of titanyl hydroxide. Biosynthesized nanoparticles have anatase polymorphic structure, spherical morphology, polydisperse size (40-60 nm) and an organic shell as determined by UV-vis spectroscopy, TEM, DLS and FTIR, respectively. Also, conversely to chemically produced nanoparticles, biosynthesized TiO2 do not display phototoxicity. In order to design less expensive and greener solar cells, biosynthesized nanoparticles were evaluated in Quantum Dot Sensitized Solar Cells (QDSSCs) and compared with chemically produced TiO2 nanoparticles. Solar cell parameters such as short circuit current density (ISC) and open circuit voltage (VOC) revealed that biosynthesized TiO2 nanoparticles can mobilize electrons in QDSSCs similarly than chemically produced TiO2. Conclusions Our results indicate that bacterial extracellular production of TiO2 nanoparticles at low temperatures represents a novel alternative for the construction of green solar cells. [ABSTRACT FROM AUTHOR]

Background Selenite (SeO3 2-) oxyanion shows severe toxicity to biota. Different bacterial strains exist that are capable of reducing SeO3 2- to non-toxic elemental selenium (Se0), with the formation of Se nanoparticles (SeNPs). These SeNPs might be exploited for technological applications due to their physico-chemical and biological characteristics. The present paper discusses the reduction of selenite to SeNPs by a strain of Bacillus sp., SeITE01, isolated from the rhizosphere of the Se-hyperaccumulator legume Astragalus bisulcatus. Results Use of 16S rRNA and GyrB gene sequence analysis positioned SeITE01 phylogenetically close to B. mycoides. On agarized medium, this strain showed rhizoid growth whilst, in liquid cultures, it was capable of reducing 0.5 and 2.0 mM SeO3 2- within 12 and 24 hours, respectively. The resultant Se0 aggregated to form nanoparticles and the amount of Se0 measured was equivalent to the amount of selenium originally added as selenite to the growth medium. A delay of more than 24 hours was observed between the depletion of SeO3 2 and the detection of SeNPs. Nearly spherical-shaped SeNPs were mostly found in the extracellular environment whilst rarely in the cytoplasmic compartment. Size of SeNPs ranged from 50 to 400 nm in diameter, with dimensions greatly influenced by the incubation times. Different SeITE01 protein fractions were assayed for SeO3 2- reductase capability, revealing that enzymatic activity was mainly associated with the membrane fraction. Reduction of SeO3 2- was also detected in the supernatant of bacterial cultures upon NADH addition. Conclusions The selenite reducing bacterial strain SeITE01 was attributed to the species Bacillus mycoides on the basis of phenotypic and molecular traits. Under aerobic conditions, the formation of SeNPs were observed both extracellularly or intracellullarly. Possible mechanisms of Se0 precipitation and SeNPs assembly are suggested. SeO3 2- is proposed to be enzimatically reduced to Se0 through redox reactions by proteins released from bacterial cells. Sulfhydryl groups on peptides excreted outside the cells may also react directly with selenite. Furthermore, membrane reductases and the intracellular synthesis of low molecular weight thiols such as bacillithiols may also play a role in SeO3 2- reduction. Formation of SeNPs seems to be the result of an Ostwald ripening mechanism [ABSTRACT FROM AUTHOR]

Abstract: In this study, a newly isolated TNT-degrading bacterium, Bacillus mycoides, was immobilized on a carrier containing 2.5% kaolin, 10% polyvinyl alcohol (PVA), 0.3% sodium alginate (SA) and 10% cell suspension. A batch experiment demonstrated that only 20.6% TNT was removed using gel beads without immobilized cells. In contrast, 92.63% and 71.94% TNT were degraded using the beads with immobilized cells and freely suspended cells, respectively. Kinetic studies showed that adsorption of TNT on the beads followed the pseudo-second order model, while biodegradation of TNT was well fitted to the first-order degrading model where the initial concentrations of TNT ranged from 20mg/L to 120mg/L. These new findings suggest that removal of TNT should employ the beads with immobilized cells where adsorption and biodegradation are combined. Immobilized cells were reused 12 times and removed more than 99.5% TNT, and when stored at 4°C for 42days, they removed more than 91.3% TNT. This demonstrates that immobilized cells can potentially be applied in a wastewater-treatment system to remove TNT. [Copyright &y& Elsevier]

Background: In Bacillus mycoides, as well as in other members of the B. cereus group, the tubulin-like protein of the division septum FtsZ is encoded by the distal gene of the cluster division and cell wall (dcw). Along the cluster the genes coding for structural proteins of the division apparatus are intermingled with those coding for enzymes of peptidoglycan biosynthesis, raising the possibility that genes with this different function might be coexpressed. Transcription of ftsZ in two model bacteria had been reported to differ: in B. subtilis, the ftsZ gene was found transcribed as a bigenic mRNA in the AZ operon; in E. coli, the transcripts of ftsZ were monogenic, expressed by specific promoters. Here we analyzed the size and the initiation sites of RNAs transcribed from ftsZ and from other cluster genes in two B. mycoides strains, DX and SIN, characterized by colonies of different chirality and density, to explore the correlation of the different morphotypes with transcription of the dcw genes. Results: In both strains, during vegetative growth, the ftsZ-specific RNAs were composed mainly of ftsZ, ftsA-ftsZ and ftsQ-ftsA-ftsZ transcripts. A low number of RNA molecules included the sequences of the upstream murG and murB genes, which are involved in peptidoglycan synthesis. No cotranscription was detected between ftsZ and the downstream genes of the SpoIIG cluster. The monogenic ftsZ RNA was found in both strains, with the main initiation site located inside the ftsA coding sequence. To confirm the promoter property of the site, a B. mycoides construct carrying the ftsA region in front of the shortened ftsZ gene was inserted into the AmyE locus of B. subtilis 168. The promoter site in the ftsA region was recognized in the heterologous cellular context and expressed as in B. mycoides. Conclusions: The DX and SIN strains of B. mycoides display very similar RNA transcription specificity. The ftsZ messenger RNA can be found either as an independent transcript or expressed together with ftsA and ftsQ and, in low amounts, with genes that are specific to peptidoglycan biosynthesis [ABSTRACT FROM AUTHOR]

ABSTRACT The effect of BW upon the operational performance of a tubular ceramic membrane was investigated for the MF of a high solids content (15 wt %) MPI feed inoculated with Bacillus mycoides spores. Three tubular ceramic Membralox™ (Pall Filtration, Bazet, France) MF membranes of pore sizes 0.8, 2.0 and 12.0 µm pore diameters were tested. A 10-s backflush every 5 min was found to be the most effective protocol during filtration experiments. Membrane cleaning using a combination of a long rinsing backflush at 1 bar, and acid and alkali steps without BW were found to be most effective after MPI filtration. Application of this protocol resulted in a flux recovery of 99.6%. PRACTICAL APPLICATIONS Pasteurization is an energy intensive process that can also affect the organoleptic properties of milk and dairy products. MF offers the possibility of replacing a thermal process with a physical (size exclusion) based one and is particularly attractive when the bacterial removal challenge involves thermophiles that resist heat treatment. While the application of MF for filtering low viscosity diary feeds is relatively well established, the filtration of high solids content, high viscosity feeds has not become well established because of low fluxes and poor transmission of solids. This article extends previous work in our laboratory that demonstrated the viability of this technology for bacterial removal from high solids content diary feeds. Here, the effect of membrane BW during both filtration and cleaning cycles is quantified, and a BW protocol is optimized. This is essential information for the practical operation of a membrane unit for this filtration application. [ABSTRACT FROM AUTHOR]

Abstract: A TNT-degrading strain, which was isolated from Fe-reducing bacterial consortia and was identified as Bacillus mycoides based on its 16S rDNA sequence, was first used to degrade TNT under aerobic or anaerobic conditions. The results shows that 93% of the initial TNT was degraded after 16h under aerobic environment, while 94% of TNT was reduced after 24h under anaerobic environment. This is attributed to slower microorganism growth under anaerobic conditions and was confirmed in a biokinetic study, where lower degradation rates were obtained under anaerobic condition. Two TNT degradation metabolites, 4-amino-2,6-dinitrotoluene and 6-amino-2,4-dinitrotoluene, were identified by GC–MS and the degradation pathways of TNT by B. mycoides were proposed. Finally, B. mycoides was used to degrade TNT in industrial wastewater, where more than 88% of the TNT was removed, irrespective of the aerobic or anaerobic conditions. [Copyright &y& Elsevier]

A pot experiment was conducted to study the effect of single and co-inoculation of Bacillus mycoides and Micrococcus roseus strains, indigenous to heavy metal (HM)–contaminated soils, on the growth and essential-nutrient and Cd uptake of maize in a soil polluted with 100 and 200 mg Cd kg−1. Increasing Cd levels significantly decreased shoot and root dry weights, and shoot P, Fe, Zn, and Mn uptake. All bacterial treatments significantly increased biomass and shoot nutrient uptake of plant compared with control in the soil polluted with Cd. Inoculation of plants with B. mycoides and consortium of two bacteria significantly increased, whereas M. roseus significantly decreased, shoot and root Cd uptake, and Cd transfer and translocation factors compared with control in Cd-polluted conditions. The results showed that B. mycoides and consortium of two bacteria had an effective role in phytoextraction and M. roseus was the most effective treatment in phytostabilization of Cd. [ABSTRACT FROM PUBLISHER]

Bacillus mycoides is a sporogenic Gram-positive soil bacillus of the B. cereus group. This bacillus, which forms hyphal colonies, is composed of cells connected in filaments that make up bundles and turn clock- or counterclockwise depending on the strain. A thick peptidoglycan wall gives the rod cells of these bacilli strength and shape. One approach used to study peptidoglycan neoformation in Gram positives exploits the binding properties of antibiotics such as vancomycin and ramoplanin to nascent peptidoglycan, whose localization in the cell is monitored by means of a fluorescent tag. When we treated B. mycoides strains with BODIPY-vancomycin, we found the expected accumulation of fluorescence at the midcell septa and localization along the cell sidewall in small foci distributed quite uniformly. Intense fluorescence was also observed at the poles of many cells, more clearly visible at the outer edges of the cell chains. The unusual abundance of peptidoglycan intermediates at the cell poles after cell separation suggests that the construction process of this structure is different from that of B. subtilis, in which the free poles are rarely reactive to vancomycin. [ABSTRACT FROM AUTHOR]

Introduction: The presence of microorganisms in pharmaceuticals is undesirable because they may cause spoilage of the product and may present an infection hazard to the consumers or patients. Methodology: A total of 102 samples of oral and topical non-sterile pharmaceutical products were collected at random from different drug houses and pharmacies in Iraq, to investigate the microbial contamination of these products. Bacterial isolates recovered from these medicaments were subjected to susceptibility testing against various antibiotics by disk diffusion method according to Clinical and Laboratory Standards (CLSI) guidelines. Results: The results revealed that the occurrence of Gram-positive bacteria was in oral and topical medicaments while Gram-negative bacteria were only detected in topical medicaments. More than 58% of Bacillus isolates were resistant to lincomycin and Bacillus mycoides isolates were resistant to beta-lactam antibiotics and trimethoprim-sulfamethoxazole. Staphylococcus spp. showed a relatively high resistance to ampicillin, amoxicillin, penicillin, tetracycline, and trimethoprim-sulfamethoxazole. S. epidermidis had the highest number of multi-resistant isolates. Furthermore, 87.5% of isolated Gram-negative rods showed high resistance to beta-lactam antibiotics and 75% of them were highly resistant to erythromycin. One isolate of Pseudomonas aeruginosa was the most resistant among all Gram-negative rod isolates. Conclusion: The high rate of resistance to antimicrobial agents of bacterial isolates recovered from oral and topical medicaments in this study may indicate a widespread antibiotic resistance among bacteria isolated from different sources, including those of anthropological and environmental origin. [ABSTRACT FROM AUTHOR]

A novel application of whole cells of Nocardia corallina B-276 for the deracemisation of ibuprofen is reported. This microorganism successfully hydrolysed ibuprofen nitrile to ibuprofen amide, and ibuprofen amide to ibuprofen, using a suspension of cells in a potassium phosphate buffer solution (0.1 M, pH = 7.0). These results can be explained by the presence of NHase and amidase enzymes, but the reactions are not enantioselective and low ee values were obtained. However, (R)-ibuprofen was isolated with >99% ee by a deracemisation process catalysed by N. corallina B-276. This is the first report of this kind of catalysis with this microorganism. [ABSTRACT FROM AUTHOR]

Abstract: Echinocystic acid (3β,16α-dihydroxy-olean-12-en-28-oic acid 1) is a complex compound with many bioactivities. Microbial transformation of echinocystic acid (1) by Nocardia corallina CGMCC4.1037 has been studied. Incubation of echinocystic acid with N. corallina CGMCC4.1037 afforded three metabolites: 3-oxo-16α-hydroxy-olean-12-en-28-oic acid (2), 3β,16α-dihydroxy-olean-12-en-28-oic acid 28-O-β-d-glucopyranoside (3), and 3-oxo-16α-hydroxy-olean-12-en-28-oic acid 28-O-β-d-glucopyranoside (4). Product (4) was a new product. Their structure elucidation was mainly based on the HRMS and NMR data. The possible mechanism of the regio-selective oxidation of the 3-OH and a probable sequence of these transformations were also discussed. This is the first report on the microbial transformation of echinocystic acid (1). This method may open a new route to the future modification of echinocystic acid (1). [Copyright &y& Elsevier]

Abstract: The possible transfer of genes from Bacillus thuringiensis subsp. kurstaki (Btk) to indigenous Bacillus spp. was investigated in soil samples from stands of cork oak in Orotelli (Sardinia, Italy) collected 5 years after spraying of the stands with a commercial insecticidal preparation (FORAY 48B) of Btk. Two colonies with a morphology different from that of Btk were isolated and identified as Bacillus mycoides by morphological and physiological characteristics and by 16S rDNA analysis. Amplification by the polymerase chain reaction (PCR) of the DNA of the two isolated B. mycoides colonies with primers used for the identification of the Btk cry genes showed the presence of a fragment of 238 bp of the cry1Ab9 gene that had a similarity of 100% with the sequence of the cry1Ab9 gene present in GenBank, indicating that the isolates of B. mycoides acquired part of the sequence of this gene from Btk. No cells of Btk or B. mycoides carrying the 238-bp fragment of the cry1Ab9 gene were isolated from samples of unsprayed control soil. However, the isolates of B. mycoides were not able to express the partial Cry1Ab protein. Hybridization with probes for IS231 and the cry1Ab9 gene suggested that the inverted repeated sequence, IS231, was probably involved in the transfer of the 238-bp fragment from Btk to B. mycoides. These results indicate that transfer of genes between introduced Btk and indigenous Bacillus spp. can occur in soil under field conditions. [Copyright &y& Elsevier]

The article presents abstracts submitted for presentation at the joint meeting of the APS Southern Division and the Southern Association of Agricultural Scientists in Atlanta, Georgia from February 1-2, 2009 which include "Recent advances in systematics, taxonomy, and evolution of rust fungi (Pucciniales) and their relatives," by M. C. Aime, "Efficacy of Bacillus mycoides isolate J on pecan scab," by T. B. Brenneman, and "The impact of rust diseases on the ornamental industry," by J. W. Buck.

Two thousand Bacillus cereus sensu lato isolates from food and environmental matrices were screened by PCR for the presence of cereulide-producing strains. This survey identified 73 potential emetic strains, most of which originated from non-random food and clinical samplings. None of the 460 Bacillus thuringiensis, Bacillus mycoides and Bacillus pseudomycoides strains were PCR-positive for the cereulide genetic determinants. The chromosomal and extrachromosomal gene pool diversity of a subset of 30 cereulide-producing strains was then assessed using multilocus sequence typing, large plasmid gel electrophoresis and Southern blot hybridization. The strain toxicity on boar sperm and cereulide production were also analysed. The most striking observation was the identification of two distinct clusters of cereulide-producing strains, with members of the second group (cluster II) identified as psychrotolerant B. weihenstephanensis able to grow at 8°C. Moreover, the location of the cereulide genetic determinants was shown to vary depending on the strain, indicating a probable genomic mobility. [ABSTRACT FROM AUTHOR]

Abstract: Bacillus mycoides isolate BmJ (BmJ) and Bacillus mojavensis isolate 203-7 (203-7) were tested in the greenhouse for their ability to control Glomerella cingulata var. orbiculare the causal agent of anthracnose of cucumber by induced systemic acquired resistance (SAR). BmJ and 203-7 delayed disease onset and reduced total (43% and 56%) and live spore production (38% and 49%) per mm2 of lesion area when used to induce SAR in cucumber. 203-7 also reduced lesion diameter. Induction by G. cingulata conidia resulted in delayed disease onset, reduction of number of lesions per leaf and lesion diameter. Assays of cucumber apoplastic proteins extracted 6 days after induction showed that BmJ increased β-glucanase activity by 135%, and 203-7 increased β-glucanase activity by 72% and peroxidase activity by 79% when compared to the water control. Acibenzolar-S-methyl induced the highest (P =0.05) levels of chitinase (950%) and peroxidase (420%) activity compared to water controls. Field experiments (2004 and 2005) evaluated applications of BmJ and fungicides for the control of anthracnose in cucumber (var. ‘General Lee’) and cantaloupe (var. ‘Athena’). BmJ was compared to full and half labeled rate alternate applications of azoxystrobin and chlorothalonil, and BmJ with half rate of azoxystrobin and chlorothalonil. BmJ applied seven days before inoculation reduced disease severity by 41% in cucumber in 2004 and by 24–21% in cantaloupe for both years compared to water controls which was statistically equal to the fungicide treatments. The full and half rate fungicide program provided 97–37% disease reduction compared to water controls. BmJ applied one week before inoculation significantly reduced AUDPC (P =0.05) in cucumber compared to the water control in 2004 on cantaloupe for both years while the full and half rate fungicide program were equivalent and provided the lowest AUDPC. No yield reduction was noted as a result of the disease or treatment for either cantaloupe or cucumber. [Copyright &y& Elsevier]

Chiral diarylmethanols are versatile building blocks for the preparation of biologically active substances, but they are difficult to obtain in enantiopure form. We used Nocardia corallina B-276 for the oxidative kinetic resolution of (±)-4-(chlorophenyl)phenylmethanol, 1. Two experimental methods were used: 1) Suspension of cells in a phosphate buffer solution and 2) Cells in the culture media, in a 3-L bioreactor. After 36 hrs using the first method, the ketone/alcohol ratio was 56/44 and the unoxidized alcohol had an enantiomeric ratio of 93/7, predominating the R-alcohol. [ABSTRACT FROM AUTHOR]

Chromium VI (CrVI) is one of the highly toxic heavy metals. It is widely used in a number of industries like metallurgical, electroplating, paints, pigments, inks, fungicides and photography. It enters into the natural water bodies through the industrial effluents creating water pollution. In trace amounts it is useful for some of the metabolic activities like glucose, lipid, aminoacids and nucleic acid. However at higher concentration it becomes toxic for microbes, plants and humanbeings and causes a number of serious diseases. Therefore its removal from waste water is considered to be very important. In the present article chromium removal from waste water using bacteria by biosorption, reduction and transport was reviewed. Published literature suggests that immobilized, free and living cells, their extracellular metabolites even dead bacterial biomass play an important role in chromium removal from waste water. Reduction of Cr (VI) is one of the important mechanisms for its detoxification from waste water.It was shown by the work published so far that chromium reduction was carried out by aerobic and anaerobic bacteria and iron and sulphate reducing bacteria. pH inside the bacterial cells plays an important role in the reduction of Cr (VI). Review of literature suggests that different factors like pH, temperature, redox potential and presence of other metals play an important role in the removal of Cr (VI) from waste water using bacteria. We have carried out work in our laboratory on Cr (VI) uptake from waste water by Bacillus mycoides and the results obtained are also discussed in this communication. [ABSTRACT FROM AUTHOR]

Alkene monooxygenase (AMO) fromRhodococcus rhodochrous(formerlyNocardia corallina) B-276 belongs to a family of multicomponent nonheme binuclear iron-centre oxygenases that includes the soluble methane monooxygenases (sMMOs) found in some methane-oxidizing bacteria. The enzymes catalyse the insertion of oxygen into organic substrates (mostly hydrocarbons) at the expense of O2 and NAD(P)H. AMO is remarkable in its ability to oxidize low molecular-mass alkenes to their corresponding epoxides with high enantiomeric excess. sMMO and other well-characterized homologues of AMO exhibit two adventitious activities: (1) turnover-dependent inhibition by alkynes and (2) activation by hydrogen peroxide in lieu of oxygen and NAD(P)H (the peroxide shunt reaction). Previous studies of the AMO had failed to detect these activities and opened the possibility that the mechanism of AMO might be fundamentally different from that of its homologues. Thanks to improvements in the protocols for cultivation ofR. rhodochrousB-276 and purification and assay of AMO, it has been possible to detect and characterize turnover-dependent inhibition of AMO by propyne and ethyne and activation of the enzyme by hydrogen peroxide. These results indicate a similar mechanism to that found in sMMO and also, unexpectedly, that the enantiomeric excess of the chiral epoxypropane product is significantly reduced during the peroxide shunt reaction. Inhibition of the oxygen/NADH-activated reaction, but not the peroxide shunt, by covalent modification of positively charged groups revealed an additional similarity to sMMO and may indicate very similar patterns of intersubunit interactions and/or electron transfer in both enzyme complexes. [ABSTRACT FROM AUTHOR]

Understanding the mechanisms of suppressive soils should lead to the development of new strategies to manage pests and diseases. For suppressive soils that have a biological nature, one of the first steps in understanding them is to identify the organisms contributing to this phenomenon. Here we present a new approach for identifying microorganisms involved in soil suppressiveness. This strategy identifies microorganisms that fill a niche similar to that of the pathogen by utilizing substrate utilization assays in soil. To demonstrate this approach, we examined an avocado grove where a Phytophthora cinnamomi epidemic created soils in which the pathogen could not be detected with baiting techniques, a characteristic common to many soils with suppressiveness against P. cinnamomi. Substrate utilization assays were used to identify rRNA genes (rDNA) from bacteria that rapidly grew in response to amino acids known to attract P. cinnamomi zoospores. Six bacterial rDNA intergenic sequences were prevalent in the epidemic soils but uncommon in the non-epidemic soils. These sequences belonged to bacteria related to Bacillus mycoides, Renibacterium salmoninarum, and Streptococcus pneumoniae. We hypothesize that bacteria such as these, which respond to the same environmental cues that trigger root infection by the pathogen, will occupy a niche similar to that of the pathogen and contribute to suppressiveness through mechanisms such as nutrient competition and antibiosis. [ABSTRACT FROM AUTHOR]

Nocardia species are Gram-positive bacteria responsible for systemic or cutaneous infections in humans. Nocardia brasiliensis is the most common infective agent in the cutaneous form of nocardiosis. We describe a case of a previously healthy man, who presented with lymphocutaneous Nocardia brasiliensis infection, and was successfully treated with trimethoprim-sulfamethoxazole. The identification of the isolate was confirmed by nucleotide sequence analysis of the 16S rRNA gene. [Copyright &y& Elsevier]

Abstract: The molecular identification of Nocardia species, when compared to phenotypic identification, has two primary advantages: rapid turn-around time and improved accuracy. The information content in the 5?-end of the 16S ribosomal RNA gene is sufficient for identification of most bacterial species. An evaluation was performed to demonstrate the quality of results provided by two specialized databases (RIDOM and MicroSeq 500 versions 1.1 and 1.4.3, library version 500-0125, respectively) and the more general GenBank database. In addition, these results were compared with phenotypic identifications. Partial 5?-16S rDNA sequences from 64 culture collection strains (DSM, CIP, JCM, and ATCC) were derived, in duplicate, independently in two laboratories. Furthermore, the sequences and the conventional identification results of 91 clinical Nocardia isolates were determined. With the exception of N. soli and N. cummidelens all Nocardia type strains were distinguishable using 5?-16S rDNA sequencing. Assuming a normal distribution for the pairwise distances of all unique Nocardia sequences and choosing a reporting criterion of ?99.12% similarity for a “distinct species”, a statistical error probability of 1.0% can be calculated. When the various databases were searched with the clinical isolate sequences RIDOM gave a perfect match in 71.4% of cases whereas MicroSeq yielded a perfect match in only 26.4%. The GenBank service gave a 100% similarity in 59.3% but in 70.4% of these cases the results obtained were not exclusive for a single Nocardia species. Conventional methods gave a correct identification in 59 cases, although most recent taxonomic changes were not taken into account. The RIDOM service (http://www.ridom-rdna.de/) is in the process of making available a comprehensive and high-quality database for bacterial identification purposes and provides excellent results for the majority of Nocardia isolates. [Copyright &y& Elsevier]

Background: Bacillus mycoides Flügge, a Gram-positive, non-motile soil bacterium assigned to Bacillus cereus group, grows on agar as chains of cells linked end to end, forming radial filaments curving clock- or counter-clockwise (SIN or DX morphotypes). The molecular mechanism causing asymmetric curving is not known: our working hypothesis considers regulation of filamentous growth as the prerequisite for these morphotypes. Results: SIN and DX strains isolated from the environment were classified as B. mycoides by biochemical and molecular biology tests. Growth on agar of different hardness and nutrient concentration did not abolish colony patterns, nor was conversion between SIN and DX morphotypes ever noticed. A number of morphotype mutants, all originating from one SIN strain, were obtained. Some lost turn direction becoming fluffy, others became round and compact. All mutants lost wild type tight aggregation in liquid culture. Growth on agar was followed by microscopy, exploring the process of colony formation and details of cell divisions. A region of the dcw (division cell wall) cluster, including ftsQ, ftsA, ftsZ and murC, was sequenced in DX and SIN strains as a basis for studying cell division. This confirmed the relatedness of DX and SIN strains to the B. cereus group. Conclusions: DX and SIN asymmetric morphotypes stem from a close but not identical genomic context. Asymmetry is established early during growth on agar. Wild type bacilli construct mostly uninterrupted filaments with cells dividing at the free ends: they "walk" longer distances compared to mutants, where enhanced frequency of cell separation produces new growing edges resulting in round compact colonies. [ABSTRACT FROM AUTHOR]

Whole cells of Nocardia corallina B-276 oxidized enantioselectively racemates of arylethyl carbinols, at 0.5 mM, to give ketones in yields from 4 to 97% (w/w) and the unreacted alcohols showing enantiomeric excess ranging from 5 to > 99%. The configuration of the resulting alcohol is (R). [ABSTRACT FROM AUTHOR]

A novel α-amino-acid esterase possessing some properties favorable for the synthesis of d-amino acid-containing peptides has been purified from the culture broth of Bacillus mycoides. The enzyme consisted of 4 subunits of 39 kDa, had an isoelectric point of 7.0, and showed its maximum activity at around 47°C and pH 7.6. The enzyme activity was strongly depressed by phenylmethanesulfonyl fluoride, but not by penicillin G or ampi-cillin, suggesting that the protein is a serine enzyme lacking penicillin-binding ability. The enzyme hydrolyzed a variety of d- and l-amino acid methyl esters with concomitant formation of homooligomers from d-Phe, d-Trp, d-Tyr, and D-Asp(OCH3) methyl esters, but it did not act on the d- or l-amino acid amides tested. Incubation of a mixture of Ac-d-Phe-OMe and d-/l-Leu-NH2 with the enzyme yielded Ac-d-Phe-d/l-Leu-NH2 together with Ac-d-Phe-OH, the hydrolysate of the carboxyl component. To its credit, the enzyme failed to hydrolyze casein as well as peptides including diastereomers of diphenylala-nine and dialanine, indicating that the enzyme would not cause secondary hydrolysis of once-formed peptides. These observations indicate the potential utility of the newly isolated enzyme for the synthesis of d-amino acid-containing peptides. [ABSTRACT FROM AUTHOR]

Identifies the alkene monooxygenase in Nocardia corallina B-276 as the trichloroethene (TCE)-oxidizing enzyme system. Evidence that the alkene monooxygenase is encoded by the linear plasmid pNC30; Kinetics of TCE and propene degradation; Substrate specificity of the alkene monooxygenase.

(lS)-Verbenone, (S)-perillyl acid, cinnamic acid, meta-nitrocinnamic acid, veratric acid and 2-naphthoic acid were prepared, at 1 mM scale, from the corresponding alcohols or aldehydes with whole cells of Nocardia corallina B-276, in yields from 19 to 71% (w/w). Similar microbiological oxidations gave poor yields with the heterocyclic alcohols: 3-pyridylmethanol, 4-flavanol and 4-chromanol. [ABSTRACT FROM AUTHOR]

Whole cells of Nocardia corallina B-276 catalyse the stereoselective epoxygenation of alkenes to chiral epoxides. The bacterium expresses an enzyme, alkene monooxygenase, which catalyses the epoxygenation reaction stereoselectively. The enzyme consists of a terminal oxygenase (epoxygenase), an NADH-dependent reductase (reductase) and a regulatory component (coupling protein). The epoxygenase component contains a bridged diiron centre similar to that found in the hydroxylase component of soluble methane monooxygenase. Sequence-alignment modelling, supported by chemical modification and fluorescence probing, identified a hydrophobic oxygen/substrate binding site within the epoxygenase. The diiron centre was coordinated by the two His and two Glu residues from two conserved Glu-Xaa-Xaa-His sequences and by two further Glu residues. Molecular docking of substrates and products into the proposed active-site model of the epoxygenase suggested that Ala91 and Ala185 were responsible for the stereoselectivity exerted by AMO. It is proposed that these residues clamped the intermediate and/or product of the reaction, thereby controlling the configuration of the epoxide produced. In soluble methane monooxygenase these residues are replaced by two Gly residues which do not provide sufficient steric hindrance to prevent rotation of the intermediate in the active site and, therefore, the product of the reaction catalysed by this enzyme is achiral. [ABSTRACT FROM AUTHOR]

Nocardia corallina B-276 possesses a constitutive multi-component alkene monooxygenase which catalyses the epoxidation of terminal and sub-terminal alkenes. The epoxygenase component of this systern has been purified with an overall yield of 35%. The electron paramagnetic resonance spectrum of the oxidised protein has a weak signal at g = 4.3, which we ascribe to rhombic iron and a free radical signal at gave = 2.01. Upon partial reduction with dithionite using methyl viologen as a mediator, a signal at gave = 1.9 appeared. Upon further reduction with excess dithionite a signal at g = 15 appeared with the concomitant disappearance of the gave = 1.9 signal. These results indicate that the epoxygenase contains a bridged dinuclear iron centre similar to that found in a variety of proteins involved in oxygen transport and activation as well as desaturation of fatty acids. Analysis of the products of the reaction indicates that AMO is capable of stereospecific epoxidation of alkenes producing the R-enantiomer in high yield, a reaction catalysed by very few oxygenase enzymes. Whole cells gave lower enantiomeric excess values for the epoxide and a stereospecific epoxidase enzyme has been proposed to account for this difference. Aithough alkene monooxygenase was not inhibited by ethyne, a potent inhibitor of soluble methane monooxygenase with which alkene monooxygenase shares many common features, it was weakly inhibited by propyne with an apparent Km value of 340 µM. The mechanistic implications of these physicochemical features of the enzyme are discussed. [ABSTRACT FROM AUTHOR]

Provides information on a study giving evidence that epoxides are metabolized in a CO2-dependent manner in Nocardia corallina B276. Methodology and materials used to conduct the study; Results of the study; Discussion on the results.

Reports on the identification of a region of sequence variability among individuals isolates of Bacillus anthracis as well as two closely related species, Bacillus cereus and Bacillus mycoides. Sequence-based approach for rapid differentiation among members of the group; Identification of the region of sequence divergence; Origin of sequence variation.

Seeks to establish the distribution of B. thuringiensis, including IS231A, IS231V, IS232 and IS240, with reference to their relationship with Bacillus cereus and Bacillus mycoides. Description of the diversity and differential distribution of these IS; What studies conducted on the IS revealed; Analysis of data collected; Detailed information on Bacillus cereus.