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Bacilli
Kinds of Bacilli Terms modified by Bacilli Selected AbstractsDiversity and distribution of pigmented heterotrophic bacteria in marine environmentsFEMS MICROBIOLOGY ECOLOGY, Issue 1 2006Hailian Du Abstract A systematic investigation of marine pigmented heterotrophic bacteria (PHB) based on the cultivation method and sequencing analysis of 16S rRNA genes was conducted in Chinese coastal and shelf waters and the Pacific Ocean. Both the abundance of PHB and the ratio of PHB to CFU decreased along trophic gradients from coastal to oceanic waters, with the highest values of 9.9 × 103 cell mL,1 and 39.6%, respectively, in the Yangtze River Estuary. In contrast to the total heterotrophic bacteria (TB) and CFU, which were present in the whole water column, PHB were primarily confined to the euphotic zone, with the highest abundance of PHB and ratio of PHB to CFU occurring in surface water. In total, 247 pigmented isolates were obtained during this study, and the phylogenetic analysis showed a wide genetic diversity covering 25 genera of six phylogenetic classes: Alphaproteobacteria, Gammaproteobacteria, Actinobacteria, Bacilli, Flavobacteria and Sphingobacteria. PHB belonging to Alphaproteobacteria, Flavobacteria and Sphingobacteria were obtained mainly from the South China Sea and East China Sea; PHB from the Pacific Ocean water were predominantly affiliated with Gammaproteobacteria, and most isolates from the Yangtze River Estuary fell into the classes Actinobacteria and Bacilli. The isolates exhibited various colours (e.g. golden, yellow, red, pink and orange), with genus or species specificity. Furthermore, the pigment of PHB cells absorbed light mainly in the wavelength range between 450 and 550 nm. In conclusion, our work has revealed that PHB with broad genetic diversity are widely distributed in the marine environment, and may account for up to 39.6% of culturable bacteria, equivalent to 1.4% of the total microbial community. This value might even be underestimated because it is probable that not all pigmented bacteria were isolated. Their abundance and genetic distribution are heavily influenced by environmental properties, such as light and nutrition, suggesting that they have important roles in the marine ecosystem, especially in the absorption of visible light. [source] Dimer-induced signal propagation in Spo0AMOLECULAR MICROBIOLOGY, Issue 3 2004K. Muchová Summary Spo0A, the response regulator protein controlling the initiation of sporulation in Bacillus, has two distinct domains, an N-terminal phosphoacceptor (or receiver) domain and a C-terminal DNA-binding (or effector) domain. The phosphoacceptor domain mediates dimerization of Spo0A on phosphorylation. A comparison of the crystal structures of phosphorylated and unphosphorylated response regulators suggests a mechanism of activation in which structural changes originating at the phosphorylatable aspartate extend to the ,4,5,5 surface of the protein. In particular, the data show an important role in downstream signalling for a conserved aromatic residue (Phe-105 in Spo0A), the conformation of which alters upon phosphorylation. In this study, we have prepared a Phe-105 to Ala mutant to probe the contribution of this residue to Spo0A function. We have also made an alanine substitution of the neighbouring residue Tyr-104 that is absolutely conserved in the Spo0As of spore-forming Bacilli. The spo0A(Y104A) and spo0A(F105A) alleles severely impair sporulation in vivo. In vitro phosphorylation of the purified proteins by phosphoramidate is unaffected, but dimerization and DNA binding are abolished by the mutations. We have identified intragenic suppressor mutations of spo0A(F105A) and shown that these second-site mutations in the purified proteins restore phosphorylation-dependent dimer formation. Our data support a model in which dimerization and signal transduction between the two domains of Spo0A are mediated principally by the ,4,5,5 signalling surface in the receiver domain. [source] Evolution of signalling in the sporulation phosphorelayMOLECULAR MICROBIOLOGY, Issue 2 2002Keith Stephenson Summary Two-component and phosphorelay signal transduction systems are believed to function as environ-mental sensors that programme gene expression to the composition of the ecological niche in which a microbe normally resides. The question of how evolutionarily related bacteria that occupy different environments change their signal transduction pathways to adapt to such environments was asked of the sporulation phosphorelay of Bacillus subtilis, Bacillus halodurans, Bacillus anthracis and Bacillus stearothermophilus. Comparison of the primary amino acid sequence of phosphorelay proteins with the known structural and interactive properties of the B. subtilis proteins revealed that the amino acid residues of interaction surfaces between phosphorelay proteins and between a phosphorelay protein and DNA resist evolutionary change. The absolute conservation of interaction surfaces allowed the identification of sporulation sensor kinases in B. halodurans, B. anthracis and B. stearothermophilus. In these sensor kinases, the signal-sensing domains are vastly different in size and subdomain composition, with little apparent conservation between species, whereas the catalytic domains of these sensor kinases retain the high level of homology observed for the other phosphorelay proteins. Adaptation to new environments appears to result in rapid evolution of signalling domains to maximize environmental impact while maintaining identical protein,protein and protein,DNA contacts in the entire phosphorelay. In Clostridial genomes, only the Spo0A protein was found, suggesting that the anaerobic relatives of the Bacilli do not use a phosphorelay and phosphorylate Spo0A directly with sensor kinases. [source] Fecal bacterial diversity of human-habituated wild chimpanzees (Pan troglodytes schweinfurthii) at Mahale Mountains National Park, Western TanzaniaAMERICAN JOURNAL OF PRIMATOLOGY, Issue 7 2010Brian A. Szekely Abstract Although the intestinal flora of chimpanzees has not been studied, insight into this dynamic environment can be obtained through studies on their feces. We analyzed fecal samples from human-habituated, wild chimpanzees at Mahale Mountains National Park, Tanzania, and compared microbial community profiles to determine if members of the same social group were similar. Between July and December 2007, we collected fresh fecal samples from 12 individuals: four juveniles, four adolescents, and four adults, including three parent,offspring pairs. Each sample was analyzed using Terminal-Restriction Fragment Length Polymorphism of amplified 16S rRNA genes. Twelve different profiles were generated, having between 1 and 15 Terminal-Restriction Fragments (T-RFs). Overall, a total of 23 different T-RFs were produced. Putative assignments of T-RFs corresponded to the phyla Firmicutes (Clostridia, Bacilli, and Lactobacilli), Bacteroidetes, Tenericutes (Mollicutes Class), Actinobacteria, and Proteobacteria, as well as to uncultured or unidentified organisms. Firmicutes and Bacteroidetes phyla and Mollicutes Class were the most commonly assigned in 11, 8, and 8 of the samples, respectively, with this being the first report of Mollicutes in wild chimpanzees. Principal Components Analysis (PCA) revealed clustering of nine samples, and 80.5% of the diversity was accounted for by three samples. Morisita indices of community similarity ranged between 0.00 and 0.89, with dissimiliarity (<0.5) between most samples when compared two at a time. Our findings suggest that, although phylotypes are common among individuals, profiles among members of the same social group are host-specific. We conclude that factors other than social group, such as kinship and age, may influence fecal bacterial profiles of wild chimpanzees, and recommend that additional studies be conducted. Am. J. Primatol. 72:566,574, 2010. © 2010 Wiley-Liss, Inc. [source] Gene diversity of CYP153A and AlkB alkane hydroxylases in oil-degrading bacteria isolated from the Atlantic OceanENVIRONMENTAL MICROBIOLOGY, Issue 5 2010Liping Wang Summary Alkane hydroxylases, including the integral-membrane non-haem iron monooxygenase (AlkB) and cytochrome P450 CYP153 family, are key enzymes in bacterial alkane oxidation. Although both genes have been detected in a number of bacteria and environments, knowledge about the diversity of these genes in marine alkane-degrading bacteria is still limited, especially in pelagic areas. In this report, 177 bacterial isolates, comprising 43 genera, were obtained from 18 oil-degrading consortia enriched from surface seawater samples collected from the Atlantic Ocean. Many isolates were confirmed to be the first oil-degraders in their affiliated genera including Brachybacterium, Idiomarina, Leifsonia, Martelella, Kordiimonas, Parvibaculum and Tistrella. Using degenerate PCR primers, alkB and CYP153A P450 genes were surveyed in these bacteria. In total, 82 P450 and 52 alkB gene fragments were obtained from 80 of the isolates. These isolates mainly belonged to Alcanivorax, Bacillus, Erythrobacter, Martelella, Parvibaculum and Salinisphaera, some of which were reported, for the first time, to encode alkane hydroxylases. Phylogenetic analysis showed that both genes were quite diverse and formed several clusters, most of which were generated from various Alcanivorax bacteria. Noticeably, some sequences, such as those from the Salinisphaera genus, were grouped into a distantly related novel cluster. Inspection of the linkage between gene and host revealed that alkB and P450 tend to coexist in Alcanivorax and Salinisphaera, while in all isolates of Parvibaculum, only P450 genes were found, but of multiple homologues. Multiple homologues of alkB mostly cooccurred in Alcanivorax isolates. Conversely, distantly related isolates contained similar or even identical sequences. In summary, various oil-degrading bacteria, which harboured diverse P450 and alkB genes, were found in the surface water of Atlantic Ocean. Our results help to show the diversity of P450 and alkB genes in prokaryotes, and to portray the geographic distribution of oil-degrading bacteria in marine environments. [source] Volatile organic compounds: a potential direct long-distance mechanism for antagonistic action of Fusarium oxysporum strain MSA 35ENVIRONMENTAL MICROBIOLOGY, Issue 4 2009Daniela Minerdi Summary Fusarium oxysporum MSA 35 [wild-type (WT) strain] is an antagonistic Fusarium that lives in association with a consortium of bacteria belonging to the genera Serratia, Achromobacter, Bacillus and Stenotrophomonas in an Italian soil suppressive to Fusarium wilt. Typing experiments and virulence tests provided evidence that the F. oxysporum isolate when cured of the bacterial symbionts [the cured (CU) form], is pathogenic, causing wilt symptoms identical to those caused by F. oxysporum f. sp. lactucae. Here, we demonstrate that small volatile organic compounds (VOCs) emitted from the WT strain negatively influence the mycelial growth of different formae speciales of F. oxysporum. Furthermore, these VOCs repress gene expression of two putative virulence genes in F. oxysporum lactucae strain Fuslat10, a fungus against which the WT strain MSA 35 has antagonistic activity. The VOC profile of the WT and CU fungus shows different compositions. Sesquiterpenes, mainly caryophyllene, were present in the headspace only of WT MSA 35. No sesquiterpenes were found in the volatiles of ectosymbiotic Serratia sp. strain DM1 and Achromobacter sp. strain MM1. Bacterial volatiles had no effects on the growth of the different ff. spp. of F. oxysporum examined. Hyphae grown with VOC from WT F. oxysporum f. sp. lactucae strain MSA 35 were hydrophobic whereas those grown without VOCs were not, suggesting a correlation between the presence of volatiles in the atmosphere and the phenotype of the mycelium. This is the first report of VOC production by antagonistic F. oxysporum MSA 35 and their effects on pathogenic F. oxysporum. The results obtained in this work led us to propose a new potential direct long-distance mechanism for antagonism by F. oxysporum MSA 35 mediated by VOCs. Antagonism could be the consequence of both reduction of pathogen mycelial growth and inhibition of pathogen virulence gene expression. [source] A metagenomic analysis of soil bacteria extends the diversity of quorum-quenching lactonasesENVIRONMENTAL MICROBIOLOGY, Issue 3 2008Kashif Riaz Summary A metagenomic library of 10 121 clones, generated from bacteria inhabiting a pasture soil from France, was screened for the presence of fosmids conferring either N -acylhomoserine lactone (NAHL) synthesis or NAHL degradation ability upon their Escherichia coli host. No clone producing NAHLs was identified whereas one, containing a 31 972 bp insert in fosmid p2H8, allowed NAHL degradation. This led to the cloning and identification of a gene, qlcA, encoding an NAHL-lactonase activity, as judged by lactone-ring closure and HPLC/MS analyses of NAHL degradation products. The qlcA gene efficiently quenched quorum-sensing regulated pathogenic functions when expressed in Pectobacterium carotovorum. The QlcA peptide belongs to the family of zinc-dependent metallohydrolases and appears to be distantly related to other NAHL-lactonases discovered in Agrobacterium, Bacillus, Photorhabdus and Rhizobium. In-silico analysis of the metagenomic insert revealed the occurrence of 20 orf, with a constant GC% and codon usage, suggesting a unique bacterial origin. Nine out of these 20 orf were homologous to genes encoding biosynthesis of arginine; they were clustered with an unusual succession argFJADBCRGH. The fosmid p2H8 is able to complement the argA, argB and argC mutants in E. coli. Phylogenetic analysis showed that 9 orf out of 20 were related to sequences from members of the Acidobacteria, supporting the hypothesis that the analysed insert might be originated from an organism related to this phylum. [source] Sponge disease: a global threat?ENVIRONMENTAL MICROBIOLOGY, Issue 6 2007Nicole S. Webster Summary Sponges are the most simple and primitive metazoans, yet they have various biological and ecological properties that make them an influential component of coral-reef ecosystems. Marine sponges provide refuge for many small invertebrates and are critical to benthic-pelagic coupling across a wide range of habitats. Reports of sponge disease have increased dramatically in recent years with sponge populations decimated throughout the Mediterranean and Caribbean. Reports also suggest an increased prevalence of sponge disease in Papua New Guinea, the Great Barrier Reef and in the reefs of Cozumel, Mexico. These epidemics can have severe impacts on the survival of sponge populations, the ecology of the reef and the fate of associated marine invertebrates. Despite the ecological and commercial importance of sponges, the understanding of sponge disease is limited. There has generally been a failure to isolate and identify the causative agents of sponge disease, with only one case confirming Koch's postulates and identifying a novel Alphaproteobacteria strain as the primary pathogen. Other potential disease agents include fungi, viruses, cyanobacteria and bacterial strains within the Bacillus and Pseudomonas genera. There is some evidence for correlations between sponge disease and environmental factors such as climate change and urban/agricultural runoff. This review summarizes the occurrence of sponge disease, describes the syndromes identified thus far, explores potential linkages with environmental change and proposes a strategy for future research towards better management of sponge disease outbreaks. [source] Characterization of bacterial pectinolytic strains involved in the water retting processENVIRONMENTAL MICROBIOLOGY, Issue 9 2003Elena Tamburini Summary Pectinolytic microorganisms involved in the water retting process were characterized. Cultivable mesophilic anaerobic and aerobic bacteria were isolated from unretted and water-retted material. A total of 104 anaerobic and 23 aerobic pectinolytic strains were identified. Polygalacturonase activity was measured in the supernatant of cell cultures; 24 anaerobic and nine aerobic isolates showed an enzymatic activity higher than the reference strains Clostridium felsineum and Bacillus subtilis respectively. We performed the first genotypic characterization of the retting microflora by a 16S amplified ribosomal DNA restriction analysis (ARDRA). Anaerobic isolates were divided into five different groups, and the aerobic isolates were clustered into three groups. 84.6% of the anaerobic and 82.6% of the aerobic isolates consisted of two main haplotypes. Partial 16S rRNA gene sequences were determined for 12 strains, representative of each haplotype. All anaerobic strains were assigned to the Clostridium genus, whereas the aerobic isolates were assigned to either the Bacillus or the Paenibacillus genus. Anaerobic isolates with high polygalacturonase (PG) activity belong to two clearly distinct phylogenetic clusters related to C. acetobutylicum,C. felsineum and C. saccharobutylicum species. Aerobic isolates with high PG activity belong to two clearly distinct phylogenetic clusters related to B. subtilisT and B. pumilusT. [source] Biophysical studies of the development of amyloid fibrils from a peptide fragment of cold shock protein BFEBS JOURNAL, Issue 9 2000Deborah K. Wilkins The peptide CspB-1, which represents residues 1,22 of the cold shock protein CspB from Bacillus subtilis, has been shown to form amyloid fibrils when solutions containing this peptide in aqueous (50%) acetonitrile are diluted in water [M. Großet al. (1999) Protein Science8, 1350,1357] We established conditions in which reproducible kinetic steps associated with the formation of these fibrils can be observed. Studies combining these conditions with a range of biophysical methods reveal that a variety of distinct events occurs during the process that results in amyloid fibrils. A CD spectrum indicative of ,,structure is observed within 1 min of the solvent shift, and its intensity increases on a longer timescale in at least two kinetic phases. The characteristic wavelength shift of the amyloid-binding dye Congo Red is established within 30 min of the initiation of the aggregation process and corresponds to one of the phases observed by CD and to changes in the Fourier transform-infrared spectrum indicative of ,,structure. Short fibrillar structures begin to be visible under the electron microscope after these events, and longer, well-defined amyloid fibrils are established on a timescale of hours. NMR spectroscopy shows that there are no significant changes in the concentration of monomeric species in solution during the events leading to fibril formation, but that soluble aggregates too large to be visible in NMR spectra are present throughout the process. A model for amyloid formation by this peptide is presented which is consistent with these kinetic data and with published work on a variety of disease-related systems. These findings support the concept that the ability to form amyloid fibrils is a generic property of polypeptide chains, and that the mechanism of their formation is similar for different peptides and proteins. [source] Tracking temporal changes of bacterial community fingerprints during the initial stages of compostingFEMS MICROBIOLOGY ECOLOGY, Issue 1 2003Patrick D Schloss Abstract The initial phase of composting is the most dynamic part of the process and is characterized by rapid increases in temperature, large swings in pH, and the degradation of simple organic compounds. DNA samples were taken from an active compost system to determine the microbial 16S rRNA gene sequences that were present during this phase. We observed two significant shifts in the composition of the microbial community, one between 12 and 24 h and the other between 60 and 72 h into the process using automated 16S,23S rRNA intergenic spacer amplification (ARISA). The 16S rRNA gene sequences adjoining the most common ARISA fragments at each time point were determined. We found that sequences related to lactic acid bacteria were most common during the first 60 h and Bacillus -type sequences were most common between 72 and 96 h. While the temperature increased steadily over the first 96 h, the pH dropped after 12 h and increased after 60 h correlating with the shift from Bacillus to lactic acid sequences and the later return to Bacillus -type sequences. [source] Isolation and characterization of a novel Bacillus sp., strain YAS1, capable of transforming tyrosol under hypersaline conditionsFEMS MICROBIOLOGY LETTERS, Issue 1 2005Slim Abdelkafi Abstract A moderately halotolerant, Gram-positive, aerobic, motile, spore-forming bacterium, designated as strain YAS1, was isolated from an olive-brine fermentation rich in aromatic compounds, after enrichment on tyrosol. Strain YAS1 grew between 25 and 45 °C and optimally at 37 °C. It grew in the presence of 0,15% (v/w) NaCl, with an optimum of 3,6% (v/w) NaCl. The DNA G + C content was found to be 49.9 mol%. Phylogenetic analysis of the 16S rRNA gene revealed that this isolate was a member of the genus Bacillus. The newly isolated strain YAS1 represents the first moderately halotolerant bacterium transforming tyrosol to p -hydroxyphenylacetic acid (PHPA) in the presence of yeast extract. [source] Production of oxalates In Vitro by Microbes Isolated from Rock Surfaces with prehistoric paints in the Lower Pecos Region, TexasGEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 1 2008Darren Hess Calcium oxalate-rich rock coatings are ubiquitous on limestone inside dry rock shelters and under bluff overhangs along canyon walls in southwestern Texas. Prehistoric pictographs occur in more than 250 such sites, and the ancient paints are encapsulated within the natural rock coating. Previous studies suggest lichens were the source of the oxalate; however, we report here that microbes cultured and isolated from samples of the coating produce oxalate in vitro. Twenty different bacteria species have been identified in samples from eight different sites, with Bacillus the most common genus, represented by five species. HPLC analyses of inoculated R2B medium after eight months of bacterial growth revealed the presence of oxalate ions in the solid phase of the growth medium. © 2008 Wiley Periodicals, Inc. [source] Extremely Alkaline (pH > 12) Ground Water Hosts Diverse Microbial CommunityGROUND WATER, Issue 4 2006George S. Roadcap Chemically unusual ground water can provide an environment for novel communities of bacteria to develop. Here, we describe a diverse microbial community that inhabits extremely alkaline (pH > 12) ground water from the Lake Calumet area of Chicago, Illinois, where historic dumping of steel slag has filled in a wetland. Using microbial 16S ribosomal ribonucleic acid gene sequencing and microcosm experiments, we confirmed the presence and growth of a variety of alkaliphilic ,-Proteobacteria, Bacillus, and Clostridium species at pH up to 13.2. Many of the bacterial sequences most closely matched those of other alkaliphiles found in more moderately alkaline water around the world. Oxidation of dihydrogen produced by reaction of water with steel slag is likely a primary energy source to the community. The widespread occurrence of iron-oxidizing bacteria suggests that reduced iron serves as an additional energy source. These results extend upward the known range of pH tolerance for a microbial community by as much as 2 pH units. The community may provide a source of novel microbes and enzymes that can be exploited under alkaline conditions. [source] Bacillus subtilis and B. mojavensis strains connected to food poisoning produce the heat stable toxin amylosinJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2009C. Apetroaie-Constantin Abstract Aim:, To screen and characterize toxic, heat-stable substances produced by food borne strains from Bacillus subtilis group. Methods and Results:, Using the boar sperm motility inhibition assay, six isolates from two outbreaks, out of the 94 isolates from 26 foods, were found to produce ethanol-soluble heat-stable substances that were toxic to sperm cells by depleting the mitochondrial membrane potentials. The toxic isolates were identified as Bacillus subtilis and B mojavensis. Colon carcinoma cells (Caco-2) were used to model the contact with the human digestive tract. The extract of B. subtilis F 2564/96 depolarized the mitochondria in intact Caco-2 cells similarly as in sperm cells. The substance responsible for these effects was purified using HPLC and identified by electron spray ionization ion trap mass spectrometry analysis as amylosin. The temperature requirement for amylosin production was 21,37°C for B. subtilis and 11,21°C for B. mojavensis. Both species produced amylosin in air as well as in 7,8% CO2 with 8,9% O2. Conclusions:, Food borne illness related strains of B. subtilis and B. mojavensis, produced the heat-stable toxin amylosin. Significance and Impact of the Study:, This is the first report that suggests a role for the heat-stable, ion-channel forming toxin amylosin, as a virulence factor in food borne Bacillus. [source] The safety of Bacillus subtilis and Bacillus indicus as food probioticsJOURNAL OF APPLIED MICROBIOLOGY, Issue 2 2008H.A. Hong Abstract Aims:, To conduct in vitro and in vivo assessments of the safety of two species of Bacillus, one of which, Bacillus subtilis, is in current use as a food supplement. Methods and Results:, Cultured cell lines, Caco-2, HEp-2 and the mucus-producing HT29-16E cell line, were used to evaluate adhesion, invasion and cytotoxicity. The Natto strain of B. subtilis was shown to be able to invade and lyse cells. Neither species was able to adhere significantly to any cell line. The Natto strain was also shown to form biofilms. No strain produced any of the known Bacillus enterotoxins. Disc-diffusion assays using a panel of antibiotics listed by the European Food Safety Authority (EFSA) showed that only Bacillus indicus carried resistance to clindamycin at a level above the minimum inhibitory concentration breakpoints set by the EFSA. In vivo assessments of acute and chronic dosing in guinea pigs and rabbits were made. No toxicity was observed in animals under these conditions. Conclusions:,Bacillus indicus and B. subtilis should be considered safe for oral use although the resistance of B. indicus to clindamycin requires further study. Significance and Impact of the Study:, The results support the use of B. subtilis and B. indicus strains as food supplements. [source] Identification of Bacillus spp. from Bikalga, fermented seeds of Hibiscus sabdariffa: phenotypic and genotypic characterizationJOURNAL OF APPLIED MICROBIOLOGY, Issue 1 2008L.I.I. Ouoba Abstract Aims:, To identify Bacillus spp. responsible of the fermentation of Hibiscus sabdariffa for production of Bikalga, an alkaline fermented food used as a condiment in Burkina Faso. Methods and Results:, Seventy bacteria were isolated from Bikalga produced in different regions of Burkina Faso and identified by phenotyping and genotyping using PCR amplification of the 16S-23S rDNA intergenic transcribed spacer (ITS-PCR), repetitive sequence-based PCR (rep-PCR) and DNA sequencing. The isolates were characterized as motile, rod-shaped, endospore forming, catalase positive, Gram-positive bacteria. ITS-PCR allowed typing mainly at species level. Rep-PCR was more discriminative and allowed a typing at ssp. level. The DNA sequencing combined with the Blast search program and fermentation profiles using API 50CHB system allowed an identification of the bacteria as Bacillus subtilis, B. licheniformis, B. cereus, B. pumilus, B. badius, Brevibacillus bortelensis, B. sphaericus and B. fusiformis. B. subtilis were the predominant bacterium (42) followed by B. licheniformis (16). Conclusions:, Various species and ssp. of Bacillus are involved in fermentation of H. sabdariffa for production of Bikalga. Significance and Impact of the study:, Selection of starter cultures of Bacillus for controlled production of Bikalga, selection of probiotic bacteria. [source] Bacterial synthesis of poly(hydroxybutyrate- co-hydroxyvalerate) using carbohydrate-rich mahua (Madhuca sp.) flowersJOURNAL OF APPLIED MICROBIOLOGY, Issue 1 2007P.K. Anil Kumar Abstract Aims:, The objective of the present work was to utilize an unrefined natural substrate namely mahua (Madhuca sp.) flowers, as a carbon source for the production of bacterial polyhydroxyalkanoate (PHA) copolymer by Bacillus sp-256. Methods and Results:, In the present work, three bacterial strains were tested for PHA production on mahua flower extract (to impart 20 g l,1 sugar) amongst which, Bacillus sp-256 produced higher concentration of PHA in its biomass (51%) compared with Rhizobium meliloti (31%) or Sphingomonas sp (22%). Biosynthesis of poly(hydroxybutyrate-co-hydroxyvalerate) , P(HB-co-HV) , of 90 : 10 mol% by Bacillus sp-256 was observed by gas chromatographic analysis of the polymer. Major component of the flower is sugars (57% on dry weight basis) and additionally it also contains proteins, vitamins, organic acids and essential oils. The bacterium utilized malic acid present in the substrate as a co-carbon source for the copolymer production. The flowers could be used in the form of aqueous extract or as whole flowers. PHA content of biomass (%) and yield (g l,1) in a 3·0-l stirred tank fermentor after 30 h of fermentation under constant pH (7) and dissolved oxygen content (40%) were 54% and 2·7 g l,1, respectively. Corresponding yields for control fermentation with sucrose as carbon source were 52% and 2·5 g l,1. The polymer was characterized by proton NMR. Conclusions:, Utilization of mahua flowers, a natural substrate for bacterial fermentation aimed at PHA production, had additional advantage, as the sugars and organic acids present in the flowers were metabolized by Bacillus sp-256 to synthesize P(HB-co-HV) copolymer. Significance and Impact of the Study:, Literature reports on utilization of suitable cheaper natural substrate for PHA copolymer production is scanty. Mahua flowers used in the present experiment is a cheaper carbon substrate compared with several commercial substrates and it is rich in main carbon as well as co-carbon sources that can be utilized by bacteria for PHA copolymer production. [source] Differential identification of Bacillus anthracis from environmental Bacillus species using microarray analysisJOURNAL OF APPLIED MICROBIOLOGY, Issue 4 2006J.E. Burton Abstract Aims:, To determine whether microarray analysis could be employed for the differential identification of a range of environmental Bacillus sp. from four strains of Bacillus anthracis. Methods and Results:, Oligonucleotide probes were designed that were specific to virulence factor genes of B. anthracis (pag, lef and cap), the variable number tandem repeat region of the B. anthracis vrrA gene and to the 16S-23S rRNA intergenic transcribed spacer region (ITS) and pleiotropic regulator (plcR) regions of the Bacillus cereus subgroup species. Generic probes were also designed to hybridize with conserved regions of the 16S rRNA genes of Bacillus (as a positive control), Neisseria sp., Pseudomonas sp., Streptococcus sp., Mycobacterium sp. and to all members of the Enterobacteriaceae to allow simultaneous detection of these bacteria. Identification of B. anthracis was found to rely entirely on hybridization of DNA specific to regions of the pag, lef and cap genes. Cross-reaction was observed between B. anthracis and other Bacillus species with all the other Bacillus probes tested. Results obtained using microarray hybridizations were confirmed using conventional microbiological techniques and found to have very high comparability. Conclusions:, Microarray-based assays are an effective method for the identification of B. anthracis from mixed-culture environmental samples without problems of false-positivity that have been observed with conventional PCR assays. Significance and Impact of the Study:, Identification of environmental Bacillus sp. by conventional PCR is prone to potential for reporting false-positives. This study provides a method for the exclusion of such isolates. [source] Identification of denitrifying rhizobacteria from bentgrass and bermudagrass golf greensJOURNAL OF APPLIED MICROBIOLOGY, Issue 4 2004G. Wang Abstract Aims:, As high rates of nitrogen fertilization are used in turfgrass management, there is a great potential for nitrogen loss. Research on identification of denitrifiers in turfgrass has been limited. Therefore, the aim was to identify denitrifier species and genes from turfgrass roots. Methods and Results:, Rhizobacteria were isolated from roots of bentgrass and bermudagrass in sand-based United States Golf Association (USGA) golf greens and used for denitrification biochemical analysis. Seventeen per cent (34 isolates) were identified as denitrifiers, 47% were classified as nitrate-reducers and 36% were nondenitrifiers. Identification of species of the denitrifiers was performed by chromatography fatty acid methyl ester (GC-FAME) and16S rDNA analyses. Bacillus and Pseudomonas were the major turfgrass denitrifiers. The two methods showed a 60% agreement at the genus level. Nitrite reductase genes nirK and nirS were detected in 74 and 15% of the denitrifiers, respectively, but not in nondenitrifiers. The nosZ gene encoding nitrous oxide reductase was detected in all the denitrifiers, but also in some nondenitrifiers. Conclusions:, To our knowledge, this is the first report for identification of denitrifiers and denitrification-related genes associated with turfgrass roots. Significance and Impact of the Study:, These results provide valuable data for future denitrification studies that seek to improve turfgrass nitrogen management for maximum efficiency. [source] An effective iodide formulation for killing Bacillus and Geobacillus spores over a wide temperature rangeJOURNAL OF APPLIED MICROBIOLOGY, Issue 2 2004N. Kida Abstract Aims:, To develop a sporicidal reagent which shows potent activity against bacterial spores not only at ambient temperatures but also at low temperatures. Methods and Results:, Suspension tests on spores of Bacillus and Geobacillus were conducted with the reagent based on a previously reported agent (N. Kida, Y. Mochizuki and F. Taguchi, Microbiology and Immunology 2003; 47: 279,283). The modified reagent (tentatively designated as the KMT reagent) was composed of 50 mmol l,1 EDTA-2Na, 50 mmol l,1 ferric chloride hexahydrate (FeCl3·6H2O), 50 mmol l,1 potassium iodide (KI) and 50% ethanol in 0·85% NaCl solution at pH 0·3. The KMT reagent showed significant sporicidal activity against three species of Bacillus and Geobacillus spores over a wide range of temperature. The KMT reagent had many practical advantages, i.e. activity was much less affected by organic substances than was sodium hypochlorite, it did not generate any harmful gas and it was stable for a long period at ambient temperatures. The mechanism(s) of sporicidal activity of the KMT reagent was considered to be based on active iodine species penetrating the spores with enhanced permeability of the spore cortex by a synergistic effect of acid, ethanol and generated active oxygen. Conclusions:, The data suggest that the KMT reagent shows potent sporicidal activity over a wide range temperatures and possesses many advantages for practical applications. Significance and Impact of the Study:, The results indicate development of a highly applicable sporicidal reagent against Bacillus and Geobacillus spores. [source] Expression and secretion of an ,-amylase gene from a native strain of Bacillus licheniformis in Escherichia coli by T7 promoter and putative signal peptide of the geneJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2003M. Shahhoseini Abstract The gene encoding a hyperthermostable , -amylase from a Bacillus licheniformis native strain was cloned in pET24d transcription vector containing T7 promoter, and expressed in Escherichia coli BL21(DE3) cells. Having confirmed the , -amylase activity through activity staining method on SDS,PAGE gel, the yields of production were determined in two separated intra and inter-cellular phases and compared using enzymatic assay methods. Extracellular production of the active recombinant enzyme implies the recognition of the putative signal peptide of this Bacillus sp. by E. coli secretory system. This may be because of the amino acid sequence of this signal peptide which covers all the structural parameters of a standard signal peptide processed by Lep B, the major signal peptidase in E. coli secretory system. This study recommends the use of this signal peptide for extracellular production of other foreign proteins in E. coli. [source] Molecular detection and , -glucuronidase expression of gus -marked Bacillus subtilis L-form bacteria in developing Chinese cabbage seedlingsJOURNAL OF APPLIED MICROBIOLOGY, Issue 2 2003E. Tsomlexoglou Abstract Aim: To detect L-form bacteria in developing Chinese cabbage seedlings. Methods and Results: Stable Bacillus subtilis L-forms were genetically modified to express the gus gene (encoding , -glucuronidase). Germinated seeds of Chinese cabbage were soaked in mannitol based suspensions of the L-form bacteria or with mannitol alone and after washing were grown in aseptic conditions on plant growth medium. Histochemical staining of , -glucuronidase activity (X-gluc) and Polymerase Chain Reaction (PCR) detection of the gus gene were achieved in the L-form associated seedlings. , -Glucuronidase was localized in discrete spots, mainly in the roots with staining, and was also observed in the cotyledons and base of stems. Correlation was observed between PCR detection of the gus gene and histochemical staining with detection in similar tissues. Stable L-form bacteria were non-culturable after their association with plant material. Conclusions: The gus reporter gene system with its associated histological staining for enzyme activity was used successfully for detecting B. subtilis L-form bacteria in plant material. Significance and Impact of the Study: These molecular marked L-forms should provide a specific and sensitive technique for detecting L-form bacteria in planta and offer a method for further understanding the L-form/plant association. [source] Isolation and chemical structure characterization of enzymatic lignin from Populus deltoides woodJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2010Ali Abdulkhani Abstract Cellulytic enzymes were used for the isolation and structural characterization of Populus deltoides wood lignin as a fast growing and important species in wood processing technology. The isolation was based on the hydrolysis and partial solubilization of wood xylan and cellulose using combination of Thricoderma lanuginosus xylanase, Aspergillus sp. plus, A. niger cellulase, and almond glycosidase, followed by lignin purification using Bacillus licheniformis alkaline protease (for hydrolysis of cellulase contamination). The structure of enzymatic lignin (EL) was elucidated using chemical analysis, Py-GC/MS, FTIR, and quantitative 13C-NMR techniques. Different lignin structures of acetylated and nonacetylated lignin preparation were calculated. P. deltoides EL has been determined to have an h : g : s ratio of 5 : 60 : 35. Also, P. deltoides EL contained 0.59/Ar of ,-O-4 moieties with small amounts of other structural units such as pino/syringyresinol (0.05/Ar), phenylcoumaran (0.05/Ar), and spirodienone (0.01/Ar). The degree of condensation was estimated at 20%. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Evaluation of a novel Bacillus strain from a north-western Spain hot spring as a source of extracellular thermostable lipaseJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 10 2009Francisco J. Deive Abstract BACKGROUND: Thermophilic microorganisms are receiving significant attention as a source of useful thermostable enzymes. However, the number of known strains is still limited, and very often their most interesting biocatalysts are intracellular or membrane-bound and produced at low levels. Thus, the isolation and study of novel extracellular enzyme-producing thermophilic microorganisms is very interesting. Moreover, the assessment of bioreactor performance is crucial, given the scarce information on the large-scale culture of these strains. RESULTS: The production of a thermostable extracellular lipase in submerged cultures of a thermophilic microorganism, recently isolated in north-west Spain, was investigated. The strain was identified by 16S rDNA sequencing as belonging to genus Bacillus. The influence of operating variables (i.e. pH, temperature, aeration) on lipase biosynthesis was analysed. Enzyme production at bioreactor scale was investigated, special attention being paid to the effect of aeration and agitation rates. CONCLUSION: The best conditions for the studied process were determined in shake flasks as pH 7.0, 55 °C and high aeration levels. Also, the non-association between lipase production and cell growth was ascertained. The culture of this novel strain was successfully carried out in laboratory-scale bioreactors, thus proving its potential for further applications. Copyright © 2009 Society of Chemical Industry [source] PM3-compatible zinc parameters optimized for metalloenzyme active sitesJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 14 2004Edward N. Brothers Abstract Recent studies have shown that semiempirical methods (e.g., PM3 and AM1) for zinc-containing compounds are unreliable for modeling structures containing zinc ions with ligand environments similar to those observed in zinc metalloenzymes. To correct these deficiencies a reparameterization of zinc at the PM3 level was undertaken. In this effort we included frequency corrected B3LYP/6-311G* zinc metalloenzyme ligand environments along with previously utilized experimental data. Average errors for the heats of formation have been reduced from 46.9 kcal/mol (PM3) to 14.2 kcal/mol for this new parameter set, termed ZnB for "Zinc, Biological." In addition, the new parameter sets predict geometries for the Bacillus fragilis active site model and other zinc metalloenzyme mimics that are qualitatively in agreement with high-level ab initio results, something existing parameter sets failed to do. © 2004 Wiley Periodicals, Inc. J Comput Chem 25: 1677,1692, 2004 [source] THE EFFECT of MODIFIED ATMOSPHERE PACKAGING ON the MICROBIAL ECOLOGY IN REQUEIJÃO, A PORTUGUESE WHEY CHEESEJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 2 2000MANUELA E. PINTADO The effects of modified atmosphere packaging on growth of adventitious microorganisms in Portuguese whey cheese (Requeijão) were studied following a response surface methodology using storage time (2, 6, 10 and 15 days), storage temperature (4, 12 and 18C) and fraction of CO2 in the overhead gaseous mixture also containing nitrogen (0, 50 and 100%) as manipulated variables. the viable numbers of Enterobacteriacea, staphylococci, yeasts and spore-forming bacteria in the experimental whey cheeses did not increase within 15 days when storage was at 4C under 100% CO2; those of enterococci increased significantly after 6 days under similar conditions, and a similar inhibiting effect was observed against Bacillus, pseudomonads, lactobacilli and streptococci. It was observed that 100% N2 at 4C was able to completely inhibit growth of staphylococci, lactobacilli and Bacillus for 2 days. the loci (and the nature) of the optima in terms of manipulated variables were obtained for all microbial groups studied. No true overall minimum was found, but storage conditions preset at 4C and 100% CO2 led to a 15 day extension of the shelf-life of Requeijão. [source] CYTOTOXICITY ASSESSMENT OF BACILLUS STRAINS ISOLATED FROM STREET-VENDED FOODS IN JOHANNESBURG, SOUTH AFRICAJOURNAL OF FOOD SAFETY, Issue 2 2002F.M. MOSUPYE ABSTRACT Twenty-one isolates each of Bacillus (B.) cereus, B. licheniformis and B. subtilis from street foods, collected in central Johannesburg, were randomly selected to test for cytotoxicity against McCoy 5A Mouse cells using a 3-(4,5-dimethylthizol-2-yl)-2,5-diphenyltetrazolium bromide assay, and observation by confocal scanning laser microscopy (CSLM) and scanning electron microscopy (SEM). Forty-eight percent of B. cereus, 33% of B. licheniformis and 19% of B. subtilis strains produced cytotoxic compounds. For B. cereus strains, all supernatants exhibiting cytotoxic effects were inactivated by heat treatment at 121C for 15 min. By contrast, 24% of B. licheniformis and 10% of B. subtilis supernatants exhibited cytotoxic effects following heat treatment. CSLM and SEM showed that McCoy cells treated with cytotoxic supernatants exhibited leakage and necrosis. Presence of B. cereus, B. licheniformis and B. subtilis in street foods in high numbers may pose potetnial safety risks due to production of cytotoxic compounds. [source] Expansion and Validation of a Predictive Model for the Growth of Bacillus Stearothermophilus in Military RationsJOURNAL OF FOOD SCIENCE, Issue 5 2002T.M. Ng ABSTRACT: Predictive models for the exponential growth rate (EGR) and germination, outgrowth, and lag times (GOL) of Bacillus stearothermophilus previously developed in our laboratory were expanded to include higher salt (1.5%) formulations. The expanded models were validated in 7 military meals-ready-to-eat incubated at temperatures from 45 °C to 60 °C, and tryptic soy broth incubated from 37.5 °C to 70 °C. The 95% prediction intervals for EGR were fail-safe in all the military rations tested. The 95% prediction intervals for GOL were failsafe in 5 of the 7 rations. The TSB results illustrate the dangers of using empirical models to predict microbial behavior outside the range of conditions under which the models were developed. [source] Aromatic hydrocarbon degradation genes from chronically polluted Subantarctic marine sedimentsLETTERS IN APPLIED MICROBIOLOGY, Issue 5 2009M.S. Marcos Abstract Aim:, The goal of this study was to identify functional targets to detect polycyclic aromatic hydrocarbon (PAH)-degrading bacterial populations in cold marine ecosystems. Methods and Results:, We designed a degenerate primer set targeting genes encoding the , subunit of PAH-dioxygenases from Gram-positive bacteria. This primer set was used to amplify gene fragments from metagenomic DNA isolated from Subantarctic marine sediments (Ushuaia Bay, Argentina). These gene fragments were cloned and sequenced. We identified 14 distinct groups of genes, most of them showing significant relatedness with dioxygenases from Gram-positive bacteria of the genera Rhodococcus, Mycobacterium, Nocardioides, Terrabacter and Bacillus. The level of identity with these genes, however, was low to moderate (33,62% at the amino acid level). Conclusion:, These results indicate the presence of a high diversity of hitherto unidentified dioxygenase genes in this cold polluted environment. Significance and Impact of the Study:, Subantarctic marine ecosystems are particularly vulnerable to hydrocarbon pollution, and the development of environmental restoration strategies for these environments is pressing. The information obtained in this work will be the starting point for the design of quantitative molecular tools to analyse the abundance and dynamics of these aromatic hydrocarbon-degrading bacterial populations in the marine environment. [source] | ||||||||||||||||||||||||||||||||||||||||