| evaluation of a new disinfectant for dialyzer reuse. | glutaraldehyde has been proposed to be as effective as formaldehyde as a disinfectant for reprocessing capillary hemodialyzers. formaldehyde has become the standard to which all disinfectants are compared. the two products are compared for microbiological efficacy, reuse, membrane integrity, biocompatibility, performance, residual binding and ease of removal, environmental hazards, and immunogenicity. glutaraldehyde (0.8%) is as effective as 4% formaldehyde in its microbiocidal effect. the disin ... | 1989 | 2502916 |
| electron microscopy of subnanometer surface features on metal-decorated protein crystals. | crystals of heavy riboflavin synthase from bacillus subtilis were freeze-etched and vacuum-coated at normal incidence with 0.1 to 0.4 nm of gold and silver, respectively. this decoration technique was applied to probe the protein surface for preferential nucleation sites. image processing of the electron micrographs revealed two particular decoration sites for silver and a different one for gold. according to x-ray crystallography, the riboflavin synthase molecules are spherical and smooth excep ... | 1989 | 2503619 |
| mutations that alter the helix-turn-helix region of the spollac protein: a bacillus subtilis sporulation-specific sigma factor. | it has previously been shown that spollac561, a mutation that diminishes the incidence of sporulation by more than six orders of magnitude, alters the residue at position 13 of the helix-turn-helix region of the sporulation-specific sigma factor encoded by spollac from valine to methionine (yudkin, 1987b). we have now found that four spontaneous revertants, which sporulate at an incidence of 30-60%, all contain transitions within the codon that was altered by spo-561. the mutant methionine is re ... | 1989 | 2503677 |
| partial characterization of an rna component that copurifies with saccharomyces cerevisiae rnase p. | saccharomyces cerevisiae cellular rnase p is composed of both protein and rna components that are essential for activity. the isolated holoenzyme contains a highly structured rna of 369 nucleotides that has extensive sequence similarities to the 286-nucleotide rna associated with schizosaccharomyces pombe rnase p but bears little resemblance to the analogous rna sequences in procaryotes or s. cerevisiae mitochondria. even so, the predicted secondary structure of s. cerevisiae rna is strikingly s ... | 1989 | 2503708 |
| expression of the arthrobacter viscosus penicillin g acylase gene in escherichia coli and bacillus subtilis. | the penicillin g acylase gene cloned from arthrobacter viscosus 8895gu was subcloned into vectors, and the recombinant plasmids were transferred into escherichia coli or bacillus subtilis. both e. coli and b. subtilis transformants expressed the a. viscosus penicillin g acylase. the enzyme activity was found in the intracellular portion of the e. coli transformants or in the cultured medium of the b. subtilis transformants. penicillin g acylase production in the b. subtilis transformants was 7.2 ... | 1989 | 2504107 |
| new properties of bacillus subtilis succinate dehydrogenase altered at the active site. the apparent active site thiol of succinate oxidoreductases is dispensable for succinate oxidation. | mammalian and escherichia coli succinate dehydrogenase (sdh) and e. coli fumarate reductase apparently contain an essential cysteine residue at the active site, as shown by substrate-protectable inactivation with thiol-specific reagents. bacillus subtilis sdh was found to be resistant to this type of reagent and contains an alanine residue at the amino acid position equivalent to the only invariant cysteine in the flavoprotein subunit of e. coli succinate oxidoreductases. substitution of this al ... | 1989 | 2504145 |
| primary structure of bacillus subtilis enolase gene deduced from c-dna sequence. | the nucleotide sequence for enolase gene of bacillus subtilis was determined from recombinant clone pre. the sequence was composed of 1570 bp which included the 1374 bp of the complete coding region, the 86 bp of the 5' noncoding region and the 110 bp of the 3' noncoding region containing a polyadenylation signal. in addition, the poly(a) tail was also found. a potential ribosome binding site was located 20 nucleotides upstream of the initiation codon in the 5' noncoding region. the aminoacid se ... | 1989 | 2504166 |
| protein engineering of disulfide bonds in subtilisin bpn'. | five single-disulfide mutants were studied in subtilisin bpn', a cysteine-free, secreted serine protease from bacillus amyloliquefaciens. the disulfides were engineered between residues 26-232, 29-119, 36-210, 41-80, and 148-243. these bonds connected a variety of secondary structural elements, located in buried or exposed positions at least 10 a from the catalytic ser-221, and linked residues that were separated by 39 up to 206 amino acids. all disulfide bonds formed in the enzyme when the expr ... | 1989 | 2504281 |
| the transition state transcription regulator abrb of bacillus subtilis is a dna binding protein. | the product of the abrb gene of bacillus subtilis is an ambiactive repressor and activator of the transcription of genes expressed during the transition state between vegetative growth and the onset of stationary phase and sporulation. purified abrb protein binds specifically in a highly co-operative fashion to fragments of dna containing the promoters it affects. dnase i footprints of the binding regions in these promoters revealed large protected areas of 50-120 nucleotides or more depending o ... | 1989 | 2504584 |
| a plasmid vector for the isolation of transcriptional terminators in bacillus subtilis. | a plasmid vector has been constructed that permits the positive selection of bacillus subtilis transcriptional terminator signals. the usage of the vector and its possible applications to the analysis of gene regulation in b. subtilis are described. | 1989 | 2504648 |
| influence of spo mutations on sigma e synthesis in bacillus subtilis. | bacillus subtilis mutants blocked at the same stage of development (stage ii) as strains with mutations in the structural gene for sigma e (sige[spoiigb]) were analyzed immunologically for sigma e and its precursor protein, p31. mutations at spoiil, spoiin, and spoiij loci but not at the spoiim locus significantly reduced p31 formation. mutations at the spoiiaa, spoiiac, spoiiea, spoiieb, and spoiiec loci did not affect p31 synthesis but blocked its processing into sigma e. these results demonst ... | 1989 | 2504702 |
| synthesis and biological activity of photoactive derivatives of erythromycin. | five photoactive derivatives of erythromycin have been synthesized by linking to 9(s)-aminoerythromycin either an aryl azide or a p-nitrophenyl ether. one derivative is an amide formed by reaction with (5-azido-2-formyl-phenoxy)acetic acid. three derivatives are also amides, synthesized with 4-(p-nitroguaiacoxy)butanoic acid as a photoreactive group either directly or by interposing an amino acid (glycine or tyrosine). the last derivative is the product of the aldehyde condensation of aminoeryth ... | 1989 | 2504922 |
| characterization of a new prokaryotic transcriptional activator and its dna recognition site. | the expression of the bacillus subtilis phage phi 29 dna is controlled by the viral gene 4 product, which is required for the initiation of transcription at the unique late promoter a3. protein p4 binds specifically to a phi 29 dna fragment containing the a3 promoter. dnase i footprinting analysis has shown that the dna binding region for protein p4 is located between nucleotides -50 and -100 relative to the transcription start site. methylation interference assays suggest that two eight base-pa ... | 1989 | 2504924 |
| secretory expression in escherichia coli and bacillus subtilis of human interferon alpha genes directed by staphylokinase signals. | a dna segment covering the signal sequence coding region, the ribosome binding site, and the promoter of the staphylokinase (sak) 42d gene (behnke and gerlach 1987) was cloned into puc19 to form a portable expression-secretion unit (esu). fusion of human interferon alpha 1 (hifn alpha 1) and hybrid hifn alpha 1/2 genes to this sak esu resulted in secretory expression of the two gene products in both escherichia coli and bacillus subtilis. while most of the ifn alpha was exported to the periplasm ... | 1989 | 2505056 |
| cloning and expression of the bacillus subtilis methyltransferase gene in escherichia coli ada- cells. | dna fragments of bacillus subtilis were inserted into a plasmid vector that can multiply in escherichia coli cells, and foreign genes were expressed under the control of the lac promoter. by selecting hybrid plasmids that confer an increased resistance to alkylating agents on e. coli ada- mutant cells, the b. subtilis gene dat, which encodes o6-methylguanine-dna methyltransferase, was cloned. the dat protein, with a molecular weight of about 20,000, could transfer the methyl group from methylate ... | 1989 | 2505068 |
| unusually strong immunological cross-reaction between elongation factor tu of escherichia coli and bacillus subtilis. | polyclonal antibodies were prepared against the purified elongation factor tu (ef-tu) of escherichia coli and bacillus subtilis. using the methods of western blotting and microcomplement fixation the cross-reactivities of ef-tu of 19 different prokaryotes were determined. the immunological distance were compared with the results of 16s rrna oligonucleotide analysis. an unexpectedly high cross-reactivity was revealed between the ef-tu of b. subtilis and the antiserum against the ef-tu of e. coli. ... | 1989 | 2505722 |
| novel methyl transfer during chemotaxis in bacillus subtilis. | if bacillus subtilis is incubated in radioactive methionine in the absence of protein synthesis, the methyl-accepting chemotaxis proteins (mcps) become radioactively methylated. if the bacteria are further incubated in excess nonradioactive methionine ("cold-chased") and then given the attractant aspartate, the mcps lose about half of their radioactivity due to turnover, in which lower specific activity methyl groups from s-adenosylmethionine (adomet) replace higher specific activity ones. due t ... | 1989 | 2505839 |
| possible mechanisms for the revival of glutaraldehyde-treated spores of bacillus subtilis nctc 8236. | spores of bacillus subtilis nctc 8236 were exposed to 2% alkaline glutaraldehyde and subsequently subjected to various treatments in an attempt to revive injured spores. treatment with alkali (sodium or potassium hydroxide or, to a lesser extent, sodium bicarbonate) proved to be most successful. some revival was achieved after thermal treatment. no revival was obtained with lysozyme or with various types of coat-removing agents. experiments designed to distinguish between germination and outgrow ... | 1989 | 2506164 |
| evaluation of the stability and sporicidal activity of three glutaraldehyde solutions during hospital continuous use. | two commercially available glutaraldehydes, aldetex and cidex, and one home made product, glutal, are evaluated on stability and sporicidal activity during hospital continuous use. increasing the ph and the temperature of storage, negatively affects the stability of the glutaraldehydes. the stability of cidex (initial ph 8.55) and glutal (ph 8.70) is, therefore, inferior to that of aldetex (ph 7.70). in function of time, a gradual decrease in decimal reduction value is observed for the three sol ... | 1989 | 2506326 |
| cloning and dna sequence analysis of a lactococcus bacteriophage lysin gene. | a gene for the lysin of lactococcus lactis bacteriphage phi vml3 was cloned using an escherichia coli/bacteriophage lambda host-vector system. the gene was detected by its expression of antimicrobial activity against l. lactis cells in a bioassay. the cloned fragment was analysed by sub-cloning on to e. coli plasmid vectors and by restriction endonuclease and deletion mapping. its entire dna sequence was determined and an open reading frame for the lysin structural gene was identified. the seque ... | 1989 | 2506424 |
| bacillus subtilis gene coding for constitutive o6-methylguanine-dna alkyltransferase. | we have cloned a bacillus subtilis dna fragment that could correct the defect in a constitutive o6-methylguanine-dna alkyltransferase (dat1). this fragment also corrected the hypersensitivity of the strain tkj6951(ada-1 dat-1) to n-methyl-n'-nitro-n-nitrosoguanidine (mnng). in the fragment, the gene activity resides in a region of about 850 bp which contains an open reading frame capable of coding for a protein of 165 amino acid residues. the amino acid sequence of this protein exhibits striking ... | 1989 | 2506524 |
| electrostatic effects in a large enzyme complex: subunit interactions and electrostatic potential field of the icosahedral beta 60 capsid of heavy riboflavin synthase. | the role of the electrostatic interactions in the stability of the icosahedral beta 60 capsid of heavy riboflavin synthase from bacillus subtilis has been investigated using an approach based on the theory of kirkwood and tanford. the ph dependence of the electrostatic subunit interactions agrees well with experimental data. the electrostatic subunit interaction energy has a pronounced minimum at ph 8.2 for both the ligated and ligand-free capsid. the latter is characterized by a reduction of th ... | 1989 | 2506544 |
| plasmid deletion formation in rece4 and addb72 mutants of bacillus subtilis. | plasmid deletion formation was compared in wild-type, rece4, and addb72 strains of bacillus subtilis. deletion frequencies in plasmid pgp1, as monitored with a penp-lacz fusion, were low in rece4 and high in addb72, in comparison to the wild-type strain. in the wild-type and rece4 strains, deletions between directly repeated sequences were rare. in contrast, about half of the deletions in the addb72 mutant resulted from recombination at direct repeats of 5 bp or more. the sequences at or near th ... | 1989 | 2506590 |
| binding of novel macrolide structures to macrolides-lincosamides-streptogramin b-resistant ribosomes inhibits protein synthesis and bacterial growth. | dimethylation of adenine 2058 in 23s rrna renders bacteria resistant to macrolides, lincosamides, and streptogramin b (mls resistance), because the antibiotic binding site on the altered 50s ribosomal subunit is no longer accessible. we now report that certain 6-o-methyl-11,12-cyclic carbamate derivatives of erythromycin are able to bind to dimethylated mls-resistant 50s ribosomal subunits, thus inhibiting protein synthesis and cell growth. one of these novel structures, an 11-deoxy-11-(carboxya ... | 1989 | 2506804 |
| biological studies on 1,2-benzisothiazole derivatives. i. evaluation of antibacterial, antifungal and dna-damaging activity. | the in vitro evaluation of antibacterial, antifungal and dna-damaging properties of some 1,2-benzisothiazole compounds is described. among all the tested compounds, xxx exhibited the highest antimicrobial activity. a selective antibacterial or antifungal activity was observed for compounds xxi, xxxi and xxxvi. some of the compounds tested, turned out to have genotoxic properties. | 1989 | 2506877 |
| the developmental fate of s. coelicolor hyphae depends upon a gene product homologous with the motility sigma factor of b. subtilis. | in the mycelial prokaryote s. coelicolor, whig is a gene dispensable for growth but needed for the earliest stages of spore formation in aerial hyphae. nucleotide sequencing indicates that whig encodes an rna polymerase sigma factor highly similar to the motility sigma factor (sigma 28) of b. subtilis. high copy number of an intact whig gene caused sporulation in vegetative hyphae that are usually fated to lyse without sporulating. however, the introduction of many copies of a sigma 28-dependent ... | 1989 | 2507166 |
| nucleotide sequence of a bacillus subtilis arginine regulatory gene and homology of its product to the escherichia coli arginine repressor. | in bacillus subtilis, arginine represses its biosynthetic enzymes and activates its catabolic ones via a regulator gene ahrc. a 6.2-kb ecori fragment of b. subtilis chromosomal dna that includes the ahrc gene has previously been cloned. gene ahrc was localised in a 0.8-kb hindiii sub-fragment whose nucleotide sequence was determined. an open reading frame (orf) was present whose translated amino acid sequence showed homology to that of the escherichia coli arginine repressor encoded by that orga ... | 1989 | 2507400 |
| cloning of the biotin synthetase gene from bacillus sphaericus and expression in escherichia coli and bacilli. | biotin synthetase (bs) catalyses the biotransformation of dethiobiotin (dtb) to biotin. here we report the cloning, characterization and expression of the gene encoding bs of bacillus sphaericus. a recombinant plasmid psb01, containing an 8.2-kb dna fragment from b. sphaericus, was isolated by phenotypic complementation of an escherichia coli biob strain. nucleotide sequence analysis of this fragment and n-terminal sequence determination of the recombinant protein product revealed that the biob ... | 1989 | 2507401 |
| preparation and properties of derivatives at the amino group of ristocetin aglycone. | | 1989 | 2507496 |
| bacillus subtilis mutant allele sup-3 causes lysine insertion at ochre codons: use of sup-3 in studies of translational attenuation. | the mutation sup-3 in bacillus subtilis suppresses ochre (taa) mutations at each of three codons in the 5' end of the cat-86 coding sequence. the suppressor is shown to insert lysine at ochre codons. the efficiency of suppression by sup-3 is about 15%, as determined by changing a cat-86 lys codon (codon 12) to an ochre codon and measuring the level of cat in the suppressor-containing strain. the results obtained are discussed in light of previous observations that ochre mutations at cat leader c ... | 1989 | 2507520 |
| cloning and characterization of srfb, a regulatory gene involved in surfactin production and competence in bacillus subtilis. | a tn917 insertion mutation srfb impairs the production of the lipopeptide antibiotic surfactin in bacillus subtilis. srfb is located between arog and ald in the b. subtilis genome, as determined by phage pbs1 transduction mapping, and is not linked to the previously described surfactin loci sfp or srfa. a srfb mutant was found to be also deficient in the establishment of competence. sp beta phage-mediated complementation analysis showed that both competence and surfactin production were restored ... | 1989 | 2507521 |
| cloning and characterization of the regulatory bacillus subtilis competence genes coma and comb. | coma and comb are bacillus subtilis competence genes that are identified by insertions of tn917lac. they are classified as early genes because of their expression throughout growth; the expression of late com genes increases sharply during the transition to the stationary phase. the coma and comb determinants were cloned, and the 5' and 3' termini of their transcripts were localized by low-resolution s1 nuclease protection experiments. coma and comb were found by southern blotting to be localize ... | 1989 | 2507522 |
| sequence and transcription mapping of bacillus subtilis competence genes comb and coma, one of which is related to a family of bacterial regulatory determinants. | the complete nucleotide sequences of the coma and comb loci of bacillus subtilis were determined. the products of these genes are required for the development of competence in b. subtilis and for the expression of late-expressing competence genes. the major 5' termini of both the coma and comb transcripts were determined. the inferred promoters of both coma and comb contained sequences that were similar to those found at the -10 and -35 regions of promoters that are used by sigma a-rna polymeras ... | 1989 | 2507523 |
| nucleotide sequence and genetic organization of the bacillus subtilis comg operon. | a series of tn917lac insertions define the comg region of the bacillus subtilis chromosome. comg mutants are deficient in competence and specifically in the binding of exogenous dna. the genes included in the comg region are first expressed during the transition from the exponential to the stationary growth phase. from nucleotide sequence information, it was concluded that the comg locus contains seven open reading frames (orfs), several of which overlap at their termini. high-resolution s1 nucl ... | 1989 | 2507524 |
| timing of spoii gene expression relative to septum formation during sporulation of bacillus subtilis. | spoii mutants formed heat-resistant spores when transformed with spo+ dna near the start of sporulation. many of the spores formed remained genetically spoii. it is deduced from this result and previous epistasis experiments that the spoii loci are transcribed before the spore septum is formed. | 1989 | 2507532 |
| the transition state transcription regulator abrb of bacillus subtilis is autoregulated during vegetative growth. | the dna-binding abrb protein of bacillus subtilis is an ambiactive transcriptional regulator of genes expressed during the transition state between vegetative growth and the onset of stationary phase and sporulation. studies on the transcriptional control of abrb synthesis using abrb-lacz fusions indicated that the abrb gene was autoregulated. this was consistent with the observation that purified abrb protein bound specifically to the promoter region of its own gene in dnase i protection experi ... | 1989 | 2507867 |
| the role of the sporulation gene spoiiie in the regulation of prespore-specific gene expression in bacillus subtilis. | the spoiiig gene encodes a sigma factor that determines prespore-specific gene expression during sporulation in bacillus subtilis. correct spatial and temporal expression of the spoiiig gene depends on a number of other sporulation (spo) genes, but only one of these genes, spoiiie, has a specific effect on spoiiig expression and not on gene expression in the other differentiating cell, the mother cell. however, the spoiiie gene is expressed predominantly before differentiation begins. thus, its ... | 1989 | 2507870 |
| the nucleotide sequence of the rodc operon of bacillus subtilis. | the rodc1 mutation of bacillus subtilis is a temperature-sensitive marker which affects the levels of teichoic acid synthesis and the cellular morphology. we have determined the nucleotide sequence of the bicistronic operon which contains the rodc gene and the nucleotide sequence of the rodc1 mutant allele. the temperature-sensitive phenotype of the rodc mutant is the result of a single base-pair change. a cytosine to thymine transition in the non-coding strand results in the replacement of a se ... | 1989 | 2507871 |
| expression of the rece gene during induction of the sos response in bacillus subtilis recombination-deficient strains. | a transcriptional fusion of the rece gene to a reporter gene has been constructed. expression of rece was found to be induced upon damage to dna with either mitomycin c or nalidixic acid. this specific transcriptional induction is blocked by a rece mutation. mutations affecting the recb, recf and recl gene products markedly reduced induction. however, derepression of rece seems to be independent of the atp-dependent dnase activity of the exonuclease v enzyme (also called addab enzyme). | 1989 | 2507872 |
| solid phase synthesis of the 5'-half of the initiator t-rna from b. subtilis. | using cyanoethyldiisopropylamino phosphoramidite chemistry, four oligonucleotides constituting a part of the sequence of the initiator t-rna from b. subtilis were synthesized. for the protection of the exocyclic amino functions of bases, phenoxyacetyl group was used for adenine and guanine, and acetyl group was preferred for cytosine. with these labile groups, final deprotection of the oligonucleotides can be performed in milder conditions, allowing the incorporation of 5,6-dihydrouridine in a 3 ... | 1989 | 2508060 |
| cloning and analysis of the spc ribosomal protein operon of bacillus subtilis: comparison with the spc operon of escherichia coli. | a segment of bacillus subtilis chromosomal dna homologous to the escherichia coli spc ribosomal protein operon was isolated using cloned e. coli rple (l5) dna as a hybridization probe. dna sequence analysis of the b. subtilis cloned dna indicated a high degree of conservation of spc operon ribosomal protein genes between b. subtilis and e. coli. this fragment contains dna homologous to the promoter-proximal region of the spc operon, including coding sequences for ribosomal proteins l14, l24, l5, ... | 1989 | 2508062 |
| a protein structural motif that bends dna. | the prokaryotic protein hu, integration host factor (ihf) from escherichia coli, and transcription factor 1 (tf1) from bacteriophage spo1 are closely related molecules. biochemical results suggest that the role of these proteins is to bind and bend dna. from the high-resolution structure of hu, we propose a model for this interaction with dna. crucial amino acid differences between the proteins can be rationalized in terms of their different specific functions. | 1989 | 2508086 |
| chromosomal rearrangement during sporulation of bacillus subtilis leads to the generation of a new sigma factor. | | 1989 | 2508201 |
| [a new method prepared gene probe]. | plasmid pnz8802 containing k88ac gene was digested by ecori, and the small fragment was cloned to vector plasmid pub110. one of the hybrid plasmids was named as pnz8803 which was used to gene probe for detecting varity of strains. strains containing k88ac or k88ab gene were all positive hybridization, and strains which did not containing k88ac gene were all negative hybridization. the result indicated that the gene probe was highly specificity and sensitivity. | 1989 | 2508329 |
| accumulation of the insecticidal crystal protein of bacillus thuringiensis subsp. kurstaki in post-exponential-phase bacillus subtilis. | a gene from bacillus thuringiensis subsp. kurstaki that codes for a lepidoptera-specific insecticidal toxin (delta-endotoxin) was engineered for expression in bacillus subtilis. a low-copy-number plasmid vector that replicates in escherichia coli and b. subtilis was constructed to transform b. subtilis with gene fusions first isolated and characterized in e. coli. naturally occurring promoter sequences from b. subtilis (43, veg, ctc, and spovg) were inserted upstream from the plasmid-borne struc ... | 1989 | 2508556 |
| disinfection with gaseous formaldehyde. third part: bactericidal and sporicidal effectiveness of gaseous formaldehyde and level of residues in dependence on concentration, temperature and relative humidity. | the highest rate of inactivation of staphylococcus aureus (atcc 6538), streptococcus faecium (atcc 6057) and spores of bacillus subtilis var. niger (dsm 675) was observed at a relative humidity (rh) of 90-95%. at a rh of 60% d 0.75 mg hcho l-1 air at 45 degrees c-values of 35 min and over 65 min were determined for s. aureus and for b. subtilis spores which decreased to d = 2.9 min and d = 20 min respectively at a rh of 90%. at 45 degrees c, an optimal formaldehyde (hcho) concentration for the i ... | 1989 | 2508656 |
| dna replication of plasmids from gram-positive bacteria in bacillus subtilis. plasmid pub110 as a model system. | the small high copy plasmids from gram-positive bacteria like pub110 replicate via an asymmetric rolling circle mechanism. on the based of several criteria those plasmids could be subdivided in four different families. by analysing pub110 replication in b. subtilis as a model system we have obtained information on the way by which initiation, elongation and termination in replication is accomplished in b. subtilis. | 1989 | 2508724 |
| purification and properties of the dna-binding protein hpb12 from bacillus subtilis nucleoid. | we report the purification to homogeneity of a 12 kda protein (hpb12) present in the nucleoids of bacillus subtilis. from the purification data the abundance of the protein was estimated to about 20,000 monomers per cell. the hpb12 protein is heat-stable and acid-soluble and binds preferentially to supercoiled and linearized double-stranded dnas. the binding of the protein to the supercoiled dna occurs very rapidly and appears to be cooperative. moreover, the complexes are extremely stable and d ... | 1989 | 2508749 |
| kinetic studies on the prenyl chain elongation by undecaprenyl diphosphate synthase with artificial substrate homologues. | in the undecaprenyl diphosphate synthase reaction, an allylic substrate homologue, (2z,6e,10e)-4-methyl-geranylgeranyl diphosphate was found to be a potent competitive inhibitor against the allylic primer, (2z,6e,10e)-geranylgeranyl diphosphate. on the other hand, it acted as a strong noncompetitive inhibitor against isopentenyl diphosphate. on the basis of these facts, the topology of the substrate-binding sites as well as the reason why the synthase reaction with (e)-3-methyl-3-pentenyl diphos ... | 1989 | 2509247 |
| isolation of bacillus subtilis transformation-deficient mutants and mapping of competence genes. | we have isolated and characterized 48 bacillus subtilis competence-deficient mutants. the mutants, obtained by nitrosoguanidine mutagenesis or by insertional mutagenesis with transposon tn917, had a reduced transformation frequency and a wild-type transduction frequency. the com mutations were mapped by pbs1 transduction and at least four new com genes have been identified. the mutants were also characterized for their capacity to bind and take up the transforming dna. | 1989 | 2509290 |
| a new bacteriophage vector for cloning in bacillus subtilis and the use of phi 105 for protein synthesis in maxicells. | zabarovsky and allikmets [gene 42 (1986) 119-123] have described a cloning procedure based on partial filling-in of vector and target dna cohesive ends, which strongly enriches for recombinant molecules with single insertions. improved bacillus subtilis bacteriophage phi 105 vectors containing unique cloning sites for sali have been constructed to take advantage of the partial fill-in method. the new vectors have been used to construct b. subtilis genomic libraries from which several sporulation ... | 1989 | 2509293 |
| regulation of extracellular proteins and alpha-amylase secretion by temperature in bacillus subtilis. | alpha-amylase was found to be the main protein secreted by bacillus subtilis, corresponding to 90, 87 and 60% of total extracellular proteins at 30, 40 and 45 degrees c, respectively. a change in temperature can affect the pattern of proteins secreted as detected by gel electrophoresis. 14c-leucine incorporation into extracellular proteins and their proportion at the end of the growth phase was higher at 30 degrees c than that at 40 or 45 degrees c. the effect of temperature on alpha-amylase syn ... | 1989 | 2509311 |
| sigma h-directed transcription of citg in bacillus subtilis. | the rna polymerase sigma factor sigma h is essential for the onset of endospore formation in bacillus subtilis. sigma h also is required for several additional stationary-phase-specific responses, including the normal expression of several genes that are required for the development of competence for dna uptake. it is necessary to identify the genes that are transcribed by sigma h rna polymerase (e sigma h) in order to understand the role of this sigma factor during the transition from exponenti ... | 1989 | 2509422 |
| role of sigma h in expression of the fumarase gene (citg) in vegetative cells of bacillus subtilis 168. | the fumarase gene (citg) of bacillus subtilis is transcribed from two promoter regions, citgp1 and citgp2 (p1 and p2); the p2 promoter is used by the e sigma h form of rna polymerase. in order to study the role of p1 and p2 in citg expression, the promoter region and various deletion derivatives that effectively separate p1 and p2 were fused to the escherichia coli beta-galactosidase gene (lacz) and introduced into the chromosome in single copy at the amye locus. p1 functioned to provide a relat ... | 1989 | 2509423 |
| characterization of the gene for a protein kinase which phosphorylates the sporulation-regulatory proteins spo0a and spo0f of bacillus subtilis. | the kina (spoiij) locus contains a single gene which codes for a protein of 69,170 daltons showing strong homology to the transmitter kinases of two component regulatory systems. the purified kinase autophosphorylates in the presence of atp and mediates the transfer of phosphate to the spo0a and spo0f sporulation regulatory proteins. spo0f protein was a much better phosphoreceptor for this kinase than spo0a protein in vitro. mutants with deletion mutations in the kina gene were delayed in their ... | 1989 | 2509430 |
| structural similarity among escherichia coli ftsw and roda proteins and bacillus subtilis spove protein, which function in cell division, cell elongation, and spore formation, respectively. | the escherichia coli cell division gene ftsw (2 min) was cloned and sequenced. it encodes a hydrophobic protein(s) with 414 and/or 384 amino acid residues. the deduced amino acid sequence and the hydropathy profile of the protein showed high homology with those of the e. coli roda protein functioning in determination of the cell shape and the bacillus subtilis spove protein functioning in spore formation. probably similar functional membrane proteins are involved in these three cell cycle proces ... | 1989 | 2509435 |
| a deleted variant of bacillus anthracis protective antigen is non-toxic and blocks anthrax toxin action in vivo. | anthrax toxin is the only protein secreted by bacillus anthracis that contributes to the virulence of this bacterium. an obligatory step in the action of anthrax toxin on eukaryotic cells is cleavage of the receptor-bound protective antigen (pa) protein (83 kilodaltons) to produce a 63-kilodalton, receptor-bound cooh-terminal fragment. a similar fragment can be obtained by limited treatment with trypsin. this proteolytic processing event exposes a site with high affinity for the other two anthra ... | 1989 | 2509473 |
| nucleotide sequence of a bacillus subtilis gene homologous to the dnak gene of escherichia coli. | | 1989 | 2510131 |
| synthesis and biological activity of some new pyrimidines. | | 1989 | 2510186 |
| biological activities of some 1,2,4-triazoles and 1,2,4-triazolin-5-ones. | | 1989 | 2510189 |
| a high-performance liquid chromatography method for the simultaneous assay of diaminopimelate epimerase and decarboxylase. | a sensitive and comparatively simple method for the assay of diaminopimelate (dap) decarboxylase, which simultaneously monitors dap epimerase activity, in the reverse of the biosynthetic direction, is described. the substrate, meso-dap and products ll-dap and l-lysine are derivatized with o-phthaldialdehyde and resolved by reversed-phase high-performance liquid chromatography. separation is achieved on a spherisorb c18 column using a gradient elution system. this technique offers a high degree o ... | 1989 | 2510546 |
| [the effect of synthetic proteinase inhibitors of the level of human recombinant proinsulin production, secreted by a genetically engineered strain of bacillus subtilis]. | influence of o,o,-diethyl-1-(n-alpha-hydrohexafluoroisobutyryl)amino-1- methylpropylphosphonate and o,o-diisobutyl-1-[2-(ethoxycarbonyl)aminoperfluoroprop-2-yl] -1- methylpropylphosphonate on the level of production of human proinsulin secreted by a genetically engineered culture bacillus subtilis aj 73 (pbins1.0.) has been studied. the above phosphonates, being non-toxic for microorganisms, reduced degradation of proinsulin by serine proteinases. | 1989 | 2510738 |
| disinfection with gaseous formaldehyde. fifth part: influence of albumin, mucin and blood on the bactericidal and sporicidal effectiveness. | the influence of 0.1% peptone, 0.2% albumin, 1% mucin solutions and whole human blood on the inactivation of staphylococcus aureus atcc 6538 and spores of bacillus subtilis var. niger dsm 675 was determined. the bactericidal and sporicidal effectiveness of 0.75, 1.5 and 3.2 mg hcho l-1 air at temperatures of 35, 40, 45 degrees c and a relative humidity (rh) of 90% decreased in the following order of loading substances: peptone, albumin, mucin and blood. the calculated d-values of the microorgani ... | 1989 | 2510751 |
| crystallographic studies of the mechanism of xylose isomerase. | the mechanism of xylose isomerase (ec 5.3.1.5) has been studied with x-ray crystallography. four refined crystal structures are reported at 3-a resolution: native enzyme, enzyme + glucose, enzyme + glucose + mg2+, and enzyme + glucose + mn2+. one of these structures (e.g.mg) was determined in a crystal mounted in a flow cell. the other structures were equilibrium experiments carried out by soaking crystals in substrate containing solution. these structures and other studies suggest that, contrar ... | 1989 | 2510821 |
| tus and the terminators: the arrest of replication in prokaryotes. | | 1989 | 2510933 |
| delta-aminolevulinic acid biosynthesis in escherichia coli and bacillus subtilis involves formation of glutamyl-trna. | cell-free extracts of escherichia coli and bacillus subtilis catalyzed the trna-dependent, rnase a-sensitive formation of delta-aminolevulinic acid (ala) from glutamate. cell extracts prepared from cultures of e. coli grown under aerobic or anaerobic conditions had similar levels of ala biosynthetic activity. both the trna-stimulated conversion of glutamate to ala and the conversion of glutamate-1-semialdehyde to ala were inhibited by gabaculin. however, gabaculin had no effect on the growth of ... | 1989 | 2511063 |
| effects of internal deletions on the priming activity of the phage phi 29 terminal protein. | a series of internal deletions of gene 3, coding for the phage phi 29 dna terminal protein, have been constructed and characterized. in addition, a substitution mutant in the sequence corresponding to amino acids (aa) 49-51 was obtained. the priming activity of the substitution mutant protein, in the formation of the protein p3-damp initiation complex, was drastically reduced suggesting that some of the aa present at position 49-51 are essential for p3 function. deletions of 8 to 33 aa, from aa ... | 1989 | 2511080 |
| development of an inducible and enhancible expression and secretion system in bacillus subtilis. | a set of inducible secretion vectors has been developed in bacillus subtilis based on the regulatory region and the signal peptide sequence of the sacb gene encoding an extracellular enzyme, levansucrase. the expression of the inserted foreign gene (bla) encoding tem beta-lactamase (bla), can be induced by the addition of sucrose to the medium. either the installation of a sacq expression cassette into the same secretion vector, or the use of a sacuh two-protease-deficient strain (wb30), can sig ... | 1989 | 2511081 |
| inactivation of b. subtilis spores and e. coli endotoxin by ethylene oxide. | exposure of bacillus subtilis spores to ethylene oxide (eo) showed correlation between the killing rate and the eo concentration, when the temperature was kept at 55 degrees c and the relative humidity at 100%. the co-efficient of dilution was calculated to be 0.9. the effect of eo on escherichia coli endotoxin was investigated by the chromogenic limulus amebocyte lysate (lal) test. a solution of endotoxin was dried on glass tubes and exposed to 450 or 900 mg eo/l during 1-46 h under the same co ... | 1989 | 2511214 |
| [hydrophilic-hydrophobic properties of microorganisms under various culturing conditions]. | the index of hydrophobicity and the hydrophilic-hydrophobic properties of seven microbial cultures were determined by studying their adhesion to n-hexadecane. the index of hydrophobicity was shown to be a stable characteristic of a culture grown in media with different carbon sources. as was found for escherichia coli k-12 and acinetobacter calcoaceticus k-9 whose hydrophobicity indicates were quite different, the character of cell hydration was virtually independent of the growth phase and did ... | 1989 | 2511395 |
| analysis of structural and biological parameters affecting plasmid deletion formation in bacillus subtilis. | deletions generated following stimulation by the deletion hot spot of plasmid phv15-1 were studied in bacillus subtilis. nucleotide sequencing showed that deletions extend between short direct repeat sequences. such direct repeat sequences may have homology to the sequence of the hot spot. deletion formation is rece-independent, but requires an active exonuclease v (addab) enzyme. other structural parameters like plasmid size and structure influence deletion formation. | 1989 | 2511420 |
| mutagenic activity of various kinds of cheese on the ames, rec and umu assays. | some kinds of cheese were found to be mutagenic when some inhibiting substances were removed through extraction with meoh-h2o and then treated with ion exchange resin. after this procedure, 16 types of commercial cheese out of 45 types tested showed significant mutagenicity on salmonella typhimurium ta104, ta102 and ta97 without s9 mix. almost all of these cheese also showed genotoxicity on the rec assay and the umu assay. the appearance of mutagenicity in these cheeses seemed to be related to t ... | 1989 | 2511442 |
| [antibacterial spectrum of lisosubtilin g10x]. | data on the antibacterial spectrum of lysosubtilin g10x, a preparation of lytic enzymes from bacillus subtilis sk-52 are presented. lysosubtilin was active against grampositive and gramnegative pathogenic bacteria. when it was used as a substrate of live lyophilized microbial cells the highest lysis levels were observed in b. brevis, b. cereus, b. pumilis, b. subtilis and s. faecalis. preincubation of the substrate in acid media mainly increased the levels of the lysis by enzyme preparation. som ... | 1989 | 2511813 |
| [mapping the functional segment of the initiation of replication in the pe194 staphylococcus aureus plasmid in bacillus subtilis cells]. | | 1989 | 2512108 |
| repression of sporulation: isolation and characterization of repression-resistant mutants of bacillus subtilis. | the sporulation of bacillus subtilis b34 was repressed by 24 h if glutamine or ammonium chloride but not glutamate was added at late log phase (70 h) when glucose and glutamate were nearly exhausted. glutamine-resistant mutants were isolated by selective heat treatment during the delay period induced by glutamine. glutamine-resistant mutants showed cross resistance not only against ammonium chloride but also against glucose just as glucose-resistant mutants showed resistance against nitrogenous ... | 1989 | 2512275 |
| genetic selection and dna sequences of 4.5s rna homologs. | a general strategy for cloning the functional homologs of an escherichia coli gene was used to clone homologs of 4.5s rna from other bacteria. the genes encoding these homologs were selected by their ability to complement a deletion of the gene for 4.5s rna. dna sequences of the regions encoding the homologs were determined. since this approach does not require that the homologous genes hybridize with probes generated from the e. coli sequence, the sequences of the homologs were not all similar ... | 1989 | 2512280 |
| in vitro reconstitution of a hexagonal array with a surface layer protein synthesized by bacillus subtilis harboring the surface layer protein gene from bacillus brevis 47. | bacillus brevis 47 contains two surface layer proteins, termed the outer wall protein and the middle wall protein (mwp), which form a hexagonal array in the cell wall. introduction of the mwp structural gene into bacillus subtilis by using a low-copy-number plasmid led to the synthesis of an immunoreactive polypeptide with a molecular mass almost the same as that of the mwp synthesized by b. brevis 47. biochemical analysis indicated that most of the mwp synthesized by b. subtilis was localized i ... | 1989 | 2512285 |
| effect of date extract on growth and spore germination of bacillus subtilis. | berhi date extract was studied for its effect on the growth of bacillus subtilis, staphylococcus aureus, salmonella typhi and pseudomonas aeruginosa. from 80 to 99% inhibition was observed in nutrient broth cultures containing 20% (w/v) date extract. spore germination of b. subtilis was inhibited completely using various concentrations of date extract. cell elongation and depression in the cell wall of b. subtilis were seen by scanning electron microscopy as a result of incubation in a growth me ... | 1989 | 2512469 |
| genetic evidence that rna polymerase associated with sigma a factor uses a sporulation-specific promoter in bacillus subtilis. | the construction of allele-specific suppressor mutations has enabled us to demonstrate that a sporulation-specific transcription unit in bacillus subtilis, the spoiig operon, is transcribed by a form of rna polymerase associated with sigma a, the principal sigma factor in vegetative cells. the spoiig operon encodes sporulation-specific factor sigma e, and its transcription is directed from a promoter that is activated about 1 hr after the onset of endospore formation. this promoter contains sequ ... | 1989 | 2512576 |
| nucleotide sequence of the bacillus licheniformis homologue of the sporulation locus spoiia of bacillus subtilis. | the spoiia locus of bacillus licheniformis was cloned into the phage vector phi 105j9; selection was based on the ability of the clone to complement mutations in both the first and the last of the spoiia genes of b. subtilis. the b. licheniformis dna was subcloned into m13 and sequenced; it includes three genes of identical lengths to those of b. subtilis. the average interspecies difference in nucleotide sequence is 24%; c occurs at the third position of codons 55% more often in the b. lichenif ... | 1989 | 2513372 |
| enhanced secretion of escherichia coli beta-lactamase by a spontaneous erythromycin-resistant mutant of bacillus subtilis. | an extracellular-protease-deficient mutant, me142, was isolated from bacillus subtilis as a spontaneous erythromycin-resistant (eryr) clone. this mutant showed conditional sporulation and only sporulated normally in the absence of erythromycin. in the presence of the antibiotic, sporulation was greatly reduced. production of extracellular proteases by me142 also exhibited conditional deficiency, possibly due to pleiotropic effects of the sporulation deficiency. the production of protease was 2-1 ... | 1989 | 2513373 |
| nucleotide sequence of the diaminopimelate-decarboxylase gene from bacillus subtilis. | | 1989 | 2513554 |
| sequence limits of dna strands in the arrest replication fork at the bacillus subtilis chromosome terminus. | the dna sequence limits of the leading and lagging strands in the arrested clockwise replication fork at the terminus of the bacillus subtilis chromosome have been investigated. on the basis of hybridization to synthetic oligonucleotides corresponding to known positions in the terminus region sequence it has been shown that neither the leading nor lagging strands, as they approach terc, traverse the distal inverted repeat, iri. but a small fraction of the leading strands pass through the proxima ... | 1989 | 2513558 |
| template-primer activity of 5-(hydroxymethyl)uracil-containing dna for prokaryotic and eukaryotic dna and rna polymerases. | we have utilized bacillus subtilis phage spo-1 dna as a model of irradiated dna. in this phage, all thymine (thy) residues are replaced by 5-(hydroxymethyl)uracil (5hmura), which is a known irradiation-induced derivative of dna thy. spo-1 phage is naturally devoid of other such irradiation-induced dna lesions. dnase i activated spo-1 phage dna served as well as, or even better than, the control dnas (bacillus subtilis dna and calf thymus dna) as a template-primer for escherichia coli, micrococcu ... | 1989 | 2513877 |
| temporal and spatial control of the mother-cell regulatory gene spoiiid of bacillus subtilis. | gene expression during endospore formation in bacillus subtilis is compartmentalized between the mother-cell and forespore chambers of the sporangium, which follow separate pathways of cellular differentiation. the earliest acting regulatory gene so far identified in the mother-cell line of gene expression is spoiiid, whose product is required for the transcription of the composite gene (sigk) encoding the mother-cell rna polymerase sigma-factor sigma k and for the chromosomal rearrangement that ... | 1989 | 2514119 |
| synthesis and refolding of human tissue-type plasminogen activator in bacillus subtilis. | a 1.6 kb cdna fragment encoding the mature part of the human tissue-type plasminogen activator (t-pa) was subcloned into a bacillus subtilis dual plasmid expression system [le grice et al., gene 55 (1987) 95-103]. expression of the tpa gene in this vector was regulated by the inducible escherichia coli lac elements, as well as a strong phage-t5-derived promoter and ribosome-binding site preceding the polylinker. the 5' end of the tpa gene corresponding to the n terminus of mature t-pa was fused ... | 1989 | 2514121 |
| signal peptide of bacillus subtilis alpha-amylase. | mature alpha-amylase of bacillus subtilis is known to be formed from its precursor by the removal of the nh2-terminal 41 amino acid sequence (41 amino acid leader sequence). dna fragments coding for short sequences consisting of 28 (pro as the cooh terminus) 29 (ala), 31 (ala), and 33 (ala) amino acids from the translation initiator, met, in the leader sequence were prepared and fused in frame to the dna encoding the mature alpha-amylase. the secretion activity of the 33 amino acid sequence was ... | 1989 | 2514182 |
| differential gene expression during sporulation in bacillus subtilis: regulation of the spovj gene. | the process of spore formation in the gram-positive bacterium bacillus subtilis is a simple developmental system controlled by 50 or more genes. the complex pattern of regulatory interactions between these genes is beginning to be elucidated. spovj is a poorly characterized locus in which mutations affect spore development at a relatively late stage (stage v). we have now cloned and physically characterized the spovj locus, and analysed its expression by lacz fusion. expression of spovj is tempo ... | 1989 | 2514336 |
| defects in the nutrient-dependent methylation of a membrane-associated protein in spo mutants of bacillus subtilis. | methylation of a membrane-associated protein with an apparent molecular mass of 40,000 daltons has been observed in bacillus subtilis. the methylation was nutrient dependent and occurred with a doubling time of 4 +/- 1 min. in wild-type strains, the half-life of turnover of the methyl group(s) was 17 +/- 6 min. several isogenic strains of b. subtilis containing spo0 mutations (spo0a and spo0h) were found to be normal in glutamate-dependent methylation of the protein and turnover of the methyl gr ... | 1989 | 2514344 |
| bacterial growth in mastitic whey in relation to bacterial association with mastitis. | the growth of mastitis pathogens (eight strains) and non-pathogenic bacteria (eight strains) was studied using microturbidometry. all bacteria grew well in whey originating from uninflamed quarters. however, the growth of bacteria which are not considered to be mastitis pathogens (lactobacillus plantarum, bacillus subtilis, streptococcus lactis and pseudomonas fluorescens) became suppressed by whey from mastitic quarters. on the contrary, the growth of staphylococcus aureus and escherichia coli ... | 1989 | 2514482 |
| proteolytic specificity of the neutral zinc proteinase from bacillus mesentericus strain 76 determined by digestion of an alpha-globin chain. | the proteolytic specificity of the neutral zinc proteinase from bacillus mesentericus strain 76 (mcp 76)/bacillus subtilis was determined by using the alpha-chain of walrus hemoglobin as substrate. the resulting peptides were fractionated by gel filtration and than isolated by reversed-phase hplc. the peptides were identified on the basis of their amino-acid compositions and aligned with the known sequence of the walrus alpha-chain. the proteolytic specificity of mcp 76, deduced from the experim ... | 1989 | 2514721 |
| [long-wave ultraviolet sunlight spectrum attenuates the mutagenic effect of short-wave ultraviolet light on bacillus subtilis cells]. | | 1989 | 2515053 |
| isocitrate dehydrogenase from thermophilic and mesophilic bacteria. isolation and some characteristics. | 1. simple methods incorporating the principle of selective enzyme elution from a triazinyl dye adsorbent with a mixture of nadp+ and isocitrate are described for isolating nadp+-linked isocitrate dehydrogenase in pure state from several mesophilic and thermophilic bacteria. 2. several characteristics of the isocitrate dehydrogenases have been examined, viz. molecular size, amino acid composition including the content of sulphydryl groups, thermostability and structural homology by the criterion ... | 1989 | 2515075 |
| production of diphtheria toxin crm228 in b. subtilis. | the gene coding for a nontoxic diphtheria toxin (dt), tox228, was isolated from lysogenic corynebacterium diphtheriae and cloned into pbr322. a mature form of the tox228 gene, lacking its signal sequence, was expressed in bacillus subtilis using a b. amyloliquefaciens alpha-amylase secretion vector. to test the possibility of producing partially deleted dt molecules, which could be used for cell-directed toxin conjugates, a truncated form lacking 151 amino acids from the c-terminus of the dt was ... | 1989 | 2515098 |
| the expression of a highly expressed bacillus subtilis gene is not reduced by introduction of multiple codons normally not present in such genes. | four serine or threonine codons were introduced into a highly expressed bacillus subtilis gene. the introduced codons were ones either common in highly expressed b. subtilis genes, or never used in such genes. strikingly, the level and rate of expression of the modified genes containing either type of extra codons was identical. this suggests that in b. subtilis codon usage patterns may play little or no role in effecting the level of gene expression. | 1989 | 2515101 |
| immunoelectron microscopy of bacillus subtilis cells secreting human interferon alpha 1 or staphylokinase. | post-embedding labelling techniques with colloidal gold-igg or -protein a complexes were used to determine the subcellular location of ifn alpha 1 and staphylokinase secreted from bacillus subtilis gb500 cells. both proteins were present in the cytoplasma and the cell envelope pointing to a posttranslational mode of translocation across the cytoplasmic membrane. 5- to 10-fold higher concentrations of gold particles per 0.1 micron 2 were found on the cell envelope and clustering was observed sugg ... | 1989 | 2515105 |
| glutaraldehyde: its uptake by sporing and non-sporing bacteria, rubber, plastic and an endoscope. | uptake of glutaraldehyde to bacterial spores, germinating and outgrowing spores, vegetative cells (sporing and non-sporing bacteria), various types of rubber, plastic and an endoscope was investigated. escherichia coli nctc 10418 exhibited greatest uptake, followed by bacillus subtilis nctc 8236 vegetative cells and staphylococcus aureus nctc 6571. germinated and outgrowing b. subtilis spores adsorbed more glutaraldehyde than resting spores, but less than vegetative cells. low concentrations of ... | 1989 | 2515183 |
| effect of heat and ultrasonic waves on the survival of two strains of bacillus subtilis. | the combined effect of ultrasonic (20 khz, 150 w) and heat treatment on the survival of two strains of bacillus subtilis in three suspending media (distilled water, glycerol and milk) has been studied. when spores suspended in water or milk were subjected to ultrasonic waves before heat treatments a little or no decrease of the heat resistance was observed. however, both sporicidal agents applied simultaneously (thermo-ultrasonication) decreased by 63% (b. subtilis, var. niger-40) and 74% (b. su ... | 1989 | 2515184 |
| m(iii)-facilitated recovery and concentration of enzymes from mesophilic and thermophilic organisms. | six enzymes isolated from organisms of widely differing thermal growth optima were flocculated from solution at constant ph by addition of fe(iii) solution. in all cases the enzyme concentration was 1 g.l-1 or less. flocculation profiles were generated for each enzyme over a range of fe(iii) levels. the concentrated enzymes were recovered from the fe(iii)/protein complex by solubilisation with citrate and dithionite followed by precipitation with ammonium sulphate. in all cases approximately 70- ... | 1989 | 2515216 |
| genotoxic action of sunlight upon bacillus subtilis spores: monitoring studies at tokyo, japan. | samples of bacillus subtilis spores dried on membrane filter were exposed to natural sunlight from solar-noon time at tokyo. the survival and mutation induction of wild-type (uvr) and repair-deficient (uvs) spores were determined on 66 occasions since 1979. two of the values were considered to be useful in monitoring solar uv intensity; the inverse of the time (in minutes) of exposure to kill 63% of the uvs spores ("sporocidal index") and the induced mutation frequency at 60 minutes of exposure ... | 1989 | 2515279 |