| nephelometric determination of turgor pressure in growing gram-negative bacteria. | gas vesicles were used as probes to measure turgor pressure in ancylobacter aquaticus. the externally applied pressure required to collapse the vesicles in turgid cells was compared with that in cells whose turgor had been partially or totally removed by adding an impermeable solute to the external medium. since gram-negative bacteria do not have rigid cell walls, plasmolysis is not expected to occur in the same way as it does in the cells of higher plants. bacterial cells shrink considerably be ... | 1987 | 3611024 |
| rupture of the cell envelope by induced intracellular gas phase expansion in gas vacuolate bacteria. | using a new approach, we estimated the physical strength of the cell envelopes of three species of gram-negative, gas vacuolate bacteria (microcyclus aquaticus, prosthecomicrobium pneumaticum, and meniscus glaucopis). populations of cells were slowly (0.5 to 2.9 h) saturated with argon, nitrogen, or helium to final pressures up to 100 atm (10, 132 kpa). the gas phases of the vesicles remained intact and, upon rapid (1 to 2 s) decompression to atmospheric pressure, expanded and ruptured the cells ... | 1980 | 7204336 |
| effects of bacterial host and dichloromethane dehalogenase on the competitiveness of methylotrophic bacteria growing with dichloromethane. | methylobacterium sp. strain dm4 and methylophilus sp. strain dm11 can grow with dichloromethane (dcm) as the sole source of carbon and energy by virtue of homologous glutathione-dependent dcm dehalogenases with markedly different kinetic properties (the kcat values of the enzymes of these strains are 0.6 and 3.3 s-1, respectively, and the km values are 9 and 59 microm, respectively). these strains, as well as transconjugant bacteria expressing the dcm dehalogenase gene (dcma) from dm11 or dm4 on ... | 1998 | 9546153 |
| a glutathione s-transferase with activity towards cis-1, 2-dichloroepoxyethane is involved in isoprene utilization by rhodococcus sp. strain ad45. | rhodococcus sp. strain ad45 was isolated from an enrichment culture on isoprene (2-methyl-1,3-butadiene). isoprene-grown cells of strain ad45 oxidized isoprene to 3,4-epoxy-3-methyl-1-butene, cis-1, 2-dichloroethene to cis-1,2-dichloroepoxyethane, and trans-1, 2-dichloroethene to trans-1,2-dichloroepoxyethane. isoprene-grown cells also degraded cis-1,2-dichloroepoxyethane and trans-1, 2-dichloroepoxyethane. all organic chlorine was liberated as chloride during degradation of cis-1,2-dichloroepox ... | 1998 | 9687433 |
| monooxygenase-mediated 1,2-dichloroethane degradation by pseudomonas sp. strain dca1. | a bacterial strain, designated pseudomonas sp. strain dca1, was isolated from a 1,2-dichloroethane (dca)-degrading biofilm. strain dca1 utilizes dca as the sole carbon and energy source and does not require additional organic nutrients, such as vitamins, for optimal growth. the affinity of strain dca1 for dca is very high, with a km value below the detection limit of 0.5 microm. instead of a hydrolytic dehalogenation, as in other dca utilizers, the first step in dca degradation in strain dca1 is ... | 1999 | 10347028 |
| haloalkane-utilizing rhodococcus strains isolated from geographically distinct locations possess a highly conserved gene cluster encoding haloalkane catabolism. | the sequences of the 16s rrna and haloalkane dehalogenase (dhaa) genes of five gram-positive haloalkane-utilizing bacteria isolated from contaminated sites in europe, japan, and the united states and of the archetypal haloalkane-degrading bacterium rhodococcus sp. strain ncimb13064 were compared. the 16s rrna gene sequences showed less than 1% sequence divergence, and all haloalkane degraders clearly belonged to the genus rhodococcus. all strains shared a completely conserved dhaa gene, suggesti ... | 2000 | 10781539 |
| biocontrol of the sugarcane borer eldana saccharina by expression of the bacillus thuringiensis cry1ac7 and serratia marcescens chia genes in sugarcane-associated bacteria. | the cry1ac7 gene of bacillus thuringiensis strain 234, showing activity against the sugarcane borer eldana saccharina, was cloned under the control of the tac promoter. the fusion was introduced into the broad-host-range plasmid pkt240 and the integration vector pjff350 and without the tac promoter into the broad-host-range plasmids pml122 and pkmm0. these plasmids were introduced into a pseudomonas fluorescens strain isolated from the phylloplane of sugarcane and the endophytic bacterium herbas ... | 2000 | 10877771 |
| autolysis control hypotheses for tolerance to wall antibiotics. | | 2001 | 11557453 |
| cloning and expression of the haloalkane dehalogenase gene dhma from mycobacterium avium n85 and preliminary characterization of dhma. | haloalkane dehalogenases are microbial enzymes that catalyze cleavage of the carbon-halogen bond by a hydrolytic mechanism. until recently, these enzymes have been isolated only from bacteria living in contaminated environments. in this report we describe cloning of the dehalogenase gene dhma from mycobacterium avium subsp. avium n85 isolated from swine mesenteric lymph nodes. the dhma gene has a g+c content of 68.21% and codes for a polypeptide that is 301 amino acids long and has a calculated ... | 2002 | 12147465 |
| biodegradation of bis(2-chloroethyl) ether by xanthobacter sp. strain env481. | degradation of bis(2-chloroethyl) ether (bcee) was observed to occur in two bacterial strains. strain env481, a xanthobacter sp. strain, was isolated by enrichment culturing of samples from a superfund site located in the northeastern united states. the strain was able to grow on bcee or 2-chloroethylethyl ether as the sole source of carbon and energy. bcee degradation in strain env481 was facilitated by sequential dehalogenation reactions resulting in the formation of 2-(2-chloroethoxy)ethanol ... | 2007 | 17873075 |
| ingestibility, digestibility, and engineered biological control potential of flavobacterium hibernum, isolated from larval mosquito habitats. | flavobacterium hibernum, isolated from larval habitats of the eastern tree hole mosquito, a. triseriatus, remained suspended in the larval feeding zone much longer (8 days) than other bacteria. autofluorescent protein markers were developed for the labeling of f. hibernum with a strong flavobacterial expression system. green fluorescent protein (gfp)-tagged f. hibernum cells were quickly consumed by larval mosquitoes at an ingestion rate of 9.5 × 10(4)/larva/h. the ingested f. hibernum cells wer ... | 2014 | 24296502 |
| l-2-haloacid dehalogenase (dehl) from rhizobium sp. rc1. | l-2-haloacid dehalogenase (dehl) from rhizobium sp. rc1 is a stereospecific enzyme that acts exclusively on l-isomers of 2-chloropropionate and dichloroacetate. the amino acid sequence of this enzyme is substantially different from those of other l-specific dehalogenases produced by other organisms. dehl has not been crystallised, and hence its three-dimensional structure is unavailable. herein, we review what is known concerning dehl and tentatively identify the amino acid residues important fo ... | 2016 | 27347470 |
| degradation of 2-chloroethylvinylether by ancylobacter aquaticus ad25 and ad27. | incubation of five different beta-chloroethers with slurries prepared from brackish water sediment or activated sludge revealed that bis(2-chloroethyl)ether and 2-chloroethylvinylether (2-cve) were biodegradable under aerobic conditions. after enrichment, two different cultures of ancylobacter aquaticus that are capable of growth on 2-cve were isolated. both cultures were also able to grow on 1,2-dichloroethane. the cells contained a haloalkane dehalogenase that dehalogenated 2-cve, 2-chloroethy ... | 1993 | 16349032 |
| kinetics of bacterial growth on chlorinated aliphatic compounds. | with the pure bacterial cultures ancylobacter aquaticus ad20 and ad25, xanthobacter autotrophicus gj10, and pseudomonas sp. strain ad1, monod kinetics was observed during growth in chemostat cultures on 1,2-dichloroethane (ad20, ad25, and gj10), 2-chloroethanol (ad20 and gj10), and 1,3-dichloro-2-propanol (ad1). both the michaelis-menten constants (k(m)) of the first catabolic (dehalogenating) enzyme and the monod half-saturation constants (k(s)) followed the order 2-chloroethanol, 1,3-dichloro- ... | 1993 | 16348981 |
| autotrophic growth of gas vacuolate strains of microcyclus aquaticus on methanol and hydrogen. | seven strains of microcyclus aquaticus were found to be capable of growth on methanol and hydrogen as energy sources. carbon was incorporated as co(2) via the calvin cycle, as shown by the presence of ribulosebisphosphate carboxylase activity in methanol-grown cells and by the absence of key enzymes of the ribulose monophosphate and serine pathways. in addition, incoporation of [c]methanol into cells was diminished when cultures were incubated in gas atmospheres enriched with carbon dioxide. | 1984 | 16346525 |
| bacterial wall as target for attack: past, present, and future research. | when bacteria, archaea, and eucarya separated from each other, a great deal of evolution had taken place. only then did extensive diversity arise. the bacteria split off with the new property that they had a sacculus that protected them from their own turgor pressure. the saccular wall of murein (or peptidoglycan) was an effective solution to the osmotic pressure problem, but it then was a target for other life-forms, which created lysoymes and beta-lactams. the beta-lactams, with their four-mem ... | 2003 | 14557293 |
| single-cell enumeration of an uncultivated tm7 subgroup in the human subgingival crevice. | specific oligonucleotide hybridization conditions were established for single-cell enumeration of uncultivated tm7 and io25 bacteria by using clones expressing heterologous 16s rrna. in situ analysis of human subgingival crevice specimens revealed that a greater proportion of samples from sites of chronic periodontitis than from healthy sites contained tm7 subgroup io25. in addition, io25 bacterial cells from periodontitis site samples were more abundant and fourfold longer than io25 cells from ... | 2003 | 14532094 |
| degradation of 1,2-dibromoethane by mycobacterium sp. strain gp1. | the newly isolated bacterial strain gp1 can utilize 1, 2-dibromoethane as the sole carbon and energy source. on the basis of 16s rrna gene sequence analysis, the organism was identified as a member of the subgroup which contains the fast-growing mycobacteria. the first step in 1,2-dibromoethane metabolism is catalyzed by a hydrolytic haloalkane dehalogenase. the resulting 2-bromoethanol is rapidly converted to ethylene oxide by a haloalcohol dehalogenase, in this way preventing the accumulation ... | 1999 | 10094681 |
| osmosensing by bacteria: signals and membrane-based sensors. | bacteria can survive dramatic osmotic shifts. osmoregulatory responses mitigate the passive adjustments in cell structure and the growth inhibition that may ensue. the levels of certain cytoplasmic solutes rise and fall in response to increases and decreases, respectively, in extracellular osmolality. certain organic compounds are favored over ions as osmoregulatory solutes, although k+ fluxes are intrinsic to the osmoregulatory response for at least some organisms. osmosensors must undergo tran ... | 1999 | 10066837 |
| staphylococcal cell wall: morphogenesis and fatal variations in the presence of penicillin. | the primary goal of this review is to provide a compilation of the complex architectural features of staphylococcal cell walls and of some of their unusual morphogenetic traits including the utilization of murosomes and two different mechanisms of cell separation. knowledge of these electron microscopic findings may serve as a prerequisite for a better understanding of the sophisticated events which lead to penicillin-induced death. for more than 50 years there have been controversial disputes a ... | 1998 | 9841676 |
| influence of organic nutrients and cocultures on the competitive behavior of 1,2-dichloroethane-degrading bacteria. | the effects of organic nutrients and cocultures on substrate removal by and competitive behavior of 1,2-dichloroethane-degrading bacteria were investigated. xanthobacter autotrophicus gj10 needed biotin for optimal growth on 1,2-dichloroethane. in continuous culture, dilution of biotin to a concentration below 0.2 nm resulted in washout. growth could be restored by inoculation with the 2-chloroethanol utilizer pseudomonas sp. strain gj1, leading to a new steady state in which about 1% of the mix ... | 1993 | 8250561 |
| expression of mosquitocidal toxin genes in a gas-vacuolated strain of ancylobacter aquaticus. | a series of plasmids bearing the binary toxin genes of bacillus sphaericus 2297 or 2317.3, the 100-kda toxin gene of b. sphaericus ssii-1, or the 130-kda (cryivb) toxin gene of bacillus thuringiensis subsp. israelensis were constructed and introduced into ancylobacter aquaticus by electroporation. the transformed a. aquaticus cells exhibited significant toxicity towards mosquito larvae, demonstrating a potential use of recombinant a. aquaticus for biological control of mosquitoes. | 1994 | 7993101 |
| variability of the turgor pressure of individual cells of the gram-negative heterotroph ancylobacter aquaticus. | cells of ancylobacter aquaticus were observed under phase microscopy in a chamber to which a measured pressure could be applied. the initial collapse pressure (ca), i.e., the lowest pressure needed to collapse the most pressure-sensitive gas vesicles, was measured for 69 cells. the cells were taken from cultures in low-density balanced exponential growth, and the experiments were performed quickly so that the bacteria were in a uniform physiological state at the time of measurement. the turgor p ... | 1987 | 3654582 |
| turgor pressure responses of a gram-negative bacterium to antibiotic treatment, measured by collapse of gas vesicles. | the internal hydrostatic pressure of ancylobacter aquaticus was measured by collapsing the gas vesicles with an externally applied pressure. turgor pressure was measured in conjunction with various antibiotic treatments to elucidate some aspects of the biophysics of gram-negative cell wall function. differences in the effects of these drugs either alone or in combination with other treatments were related to known biochemical activities of these drugs. our previous work, demonstrating a heteroge ... | 1988 | 3343215 |
| degradation of 1,2-dichloroethane by ancylobacter aquaticus and other facultative methylotrophs. | cultures of the newly isolated bacterial strains ad20, ad25, and ad27, identified as strains of ancylobacter aquaticus, were capable of growth on 1,2-dichloroethane (dce) as the sole carbon and energy source. these strains, as well as two other new dce utilizers, were facultative methylotrophs and were also able to grow on 2-chloroethanol, chloroacetate, and 2-chloropropionate. in all strains tested, dce was degraded by initial hydrolytic dehalogenation to 2-chloroethanol, followed by oxidation ... | 1992 | 1575500 |
| characterization of sulfur oxidizing bacteria related to biogenic sulfuric acid corrosion in sludge digesters. | biogenic sulfuric acid (bsa) corrosion damages sewerage and wastewater treatment facilities but is not well investigated in sludge digesters. sulfur/sulfide oxidizing bacteria (sob) oxidize sulfur compounds to sulfuric acid, inducing bsa corrosion. to obtain more information on bsa corrosion in sludge digesters, microbial communities from six different, bsa-damaged, digesters were analyzed using culture dependent methods and subsequent polymerase chain reaction denaturing gradient gel electropho ... | 2016 | 27430211 |
| microbial degradation of isosaccharinic acid at high ph. | intermediate-level radioactive waste (ilw), which dominates the radioactive waste inventory in the united kingdom on a volumetric basis, is proposed to be disposed of via a multibarrier deep geological disposal facility (gdf). ilw is a heterogeneous wasteform that contains substantial amounts of cellulosic material encased in concrete. upon resaturation of the facility with groundwater, alkali conditions will dominate and will lead to the chemical degradation of cellulose, producing a substantia ... | 2014 | 25062127 |
| microbial degradation of isosaccharinic acid at high ph. | intermediate-level radioactive waste (ilw), which dominates the radioactive waste inventory in the united kingdom on a volumetric basis, is proposed to be disposed of via a multibarrier deep geological disposal facility (gdf). ilw is a heterogeneous wasteform that contains substantial amounts of cellulosic material encased in concrete. upon resaturation of the facility with groundwater, alkali conditions will dominate and will lead to the chemical degradation of cellulose, producing a substantia ... | 2014 | 25062127 |
| the methanol dehydrogenase gene, mxaf, as a functional and phylogenetic marker for proteobacterial methanotrophs in natural environments. | the mxaf gene, coding for the large (α) subunit of methanol dehydrogenase, is highly conserved among distantly related methylotrophic species in the alpha-, beta- and gammaproteobacteria. it is ubiquitous in methanotrophs, in contrast to other methanotroph-specific genes such as the pmoa and mmox genes, which are absent in some methanotrophic proteobacterial genera. this study examined the potential for using the mxaf gene as a functional and phylogenetic marker for methanotrophs. mxaf and 16s r ... | 2013 | 23451130 |
| efficient co2-reducing activity of nad-dependent formate dehydrogenase from thiobacillus sp. knk65ma for formate production from co2 gas. | nad-dependent formate dehydrogenase (fdh) from candida boidinii (cbfdh) has been widely used in various co2-reduction systems but its practical applications are often impeded due to low co2-reducing activity. in this study, we demonstrated superior co2-reducing properties of fdh from thiobacillus sp. knk65ma (tsfdh) for production of formate from co2 gas. to discover more efficient co2-reducing fdhs than a reference enzyme, i.e. cbfdh, five fdhs were selected with biochemical properties and then ... | 2014 | 25061666 |
| gradients in microbial methanol uptake: productive coastal upwelling waters to oligotrophic gyres in the atlantic ocean. | methanol biogeochemistry and its importance as a carbon source in seawater is relatively unexplored. we report the first microbial methanol carbon assimilation rates (k) in productive coastal upwelling waters of up to 0.117±0.002 d(-1) (~10 nmol l(-1 )d(-1)). on average, coastal upwelling waters were 11 times greater than open ocean northern temperate (nt) waters, eight times greater than gyre waters and four times greater than equatorial upwelling (eu) waters; suggesting that all upwelling wate ... | 2013 | 23178665 |
| gradients in microbial methanol uptake: productive coastal upwelling waters to oligotrophic gyres in the atlantic ocean. | methanol biogeochemistry and its importance as a carbon source in seawater is relatively unexplored. we report the first microbial methanol carbon assimilation rates (k) in productive coastal upwelling waters of up to 0.117±0.002 d(-1) (~10 nmol l(-1 )d(-1)). on average, coastal upwelling waters were 11 times greater than open ocean northern temperate (nt) waters, eight times greater than gyre waters and four times greater than equatorial upwelling (eu) waters; suggesting that all upwelling wate ... | 2013 | 23178665 |
| isolation and identification of sodium fluoroacetate degrading bacteria from caprine rumen in brazil. | the objective of this paper was to report the isolation of two fluoroacetate degrading bacteria from the rumen of goats. the animals were adult goats, males, crossbred, with rumen fistula, fed with hay, and native pasture. the rumen fluid was obtained through the rumen fistula and immediately was inoculated 100 μl in mineral medium added with 20 mmol l(-1) sodium fluoroacetate (sf), incubated at 39°c in an orbital shaker. pseudomonas fluorescens (strain dsm 8341) was used as positive control for ... | 2012 | 22919294 |
| complete genome sequence of the facultatively chemolithoautotrophic and methylotrophic alpha proteobacterium starkeya novella type strain (atcc 8093(t)). | starkeya novella (starkey 1934) kelly et al. 2000 is a member of the family xanthobacteraceae in the order 'rhizobiales', which is thus far poorly characterized at the genome level. cultures from this species are most interesting due to their facultatively chemolithoautotrophic lifestyle, which allows them to both consume carbon dioxide and to produce it. this feature makes s. novella an interesting model organism for studying the genomic basis of regulatory networks required for the switch betw ... | 2012 | 23450099 |