| intergeneric and intrageneric conjugal transfer of plasmid-encoded antibiotic resistance determinants in leuconostoc spp. | transfer of the broad-host-range resistance plasmids pip501 and pam beta 1 from streptococcus faecalis to leuconostoc dextranicum and leuconostoc cremoris occurred between cells that were immobilized on nitrocellulose filters in the presence of dnase. transfer of pip501 to leuconostoc spp. also occurred when streptococcus sanguis and streptococcus lactis were used as donors. in addition, transfer of pip501 and pam beta 1 was observed from l. cremoris and l. dextranicum transconjugants to s. sang ... | 1988 | 2833158 |
| restriction and modification activities from streptococcus lactis me2 are encoded by a self-transmissible plasmid, ptn20, that forms cointegrates during mobilization of lactose-fermenting ability. | a self-transmissible (tra+) plasmid encoding determinants for restriction and modification activities (r+/m+) from streptococcus lactis me2 was isolated and characterized. the 28-kilobase (kb) plasmid (ptn20) was detected in lactose-fermenting (lac+) transconjugants generated from matings between s. lactis n1, and me2 variant, and a plasmid-free recipient, s. lactis lm2301. the plaquing efficiencies of prolate- and small isometric-headed phages were reduced on transconjugants containing either p ... | 1988 | 2841286 |
| role of the arginine deiminase system in protecting oral bacteria and an enzymatic basis for acid tolerance. | the arginine deiminase system was found to function in protecting bacterial cells against the damaging effects of acid environments. for example, as little as 2.9 mm arginine added to acidified suspensions of streptococcus sanguis at a ph of 4.0 resulted in ammonia production and protection against killing. the arginine deiminase system was found to have unusual acid tolerance in a variety of lactic acid bacteria. for example, for streptococcus rattus fa-1, the ph at which arginolysis was reduce ... | 1988 | 2843090 |
| in vivo gene transfer systems and transposons. | the continued development of our understanding and application of the in vivo gene transfer systems, transduction and conjugation, and the more recent use of transposons in lactic acid bacteria is reviewed. the discovery of transduction and its use as a tool for genetic analysis is described. the history of the use of conjugation in lactic acid bacteria is outlined, but more detailed discussion is reserved for in-depth analysis of the conjugation system associated with the lactose plasmids of st ... | 1988 | 2844299 |
| transposition of the streptococcus lactis ssp. lactis z270 lactose plasmid to pva797: demonstration of an insertion sequence and its relationship to an inverted repeat sequence isolated by self-annealing. | the lactose plasmid pucl22 of the single plasmid strain streptococcus lactis ssp. lactis z270 was demonstrated to fuse with the heterologous conjugative plasmid pva797. the fusion of pucl22 with pva797 occurred by recombination between a specific sequence of pucl22 and different sites of pva797. the cointegrates of pucl22::pva797 were unstable: in the absence of lactose selection, they segregated plasmids that corresponded to pva797 enlarged by one sequence of 1.2 kb, common to all derivative pl ... | 1988 | 2844300 |
| characterization of a pam beta 1 deletion derivative isolated from lactobacillus casei after conjugation. | streptococcal plasmid pam beta 1 was conjugally transferred from streptococcus lactis kb953 (a transformant of pam beta 1) into lactobacillus casei 239. a unique transconjugant, l. casei c2, was found to contain a small (11.1 kilobase pair) plasmid, ply201, which was derived by a deletion event from pam beta 1. restriction analysis revealed that ply201 was missing approximately 58% of the original pam beta 1 genome, and contained 5 single restriction sites for avai, ecori, pvuii, hpai and kpni. ... | 1988 | 2844301 |
| construction of a vector plasmid family and its use for molecular cloning in streptococcus lactis. | cloning vector plasmids have been constructed on the basis of the broad host range plasmid pam beta 1 and used for the cloning of a nisin resistance determinant in streptococcus lactis. they incorporate several desirable features for gene cloning in s. lactis and other transformable gram-positive bacteria. they carry an easily selectable erythromycin resistance marker, are present at low (6-9) or high (45-85) copy number in s. lactis and possess a convenient polyrestriction site sequence. a sign ... | 1988 | 2844302 |
| cloning of nisin resistance determinant and replication origin on 7.6-kilobase ecori fragment of pnp40 from streptococcus lactis subsp. diacetylactis drc3. | the nisin resistance determinant and an origin of replication on pnp40, a plasmid of about 60 kilobases that is present in streptococcus lactis subsp. diacetylactis drc3, was cloned on a 7.6-kilobase ecori fragment. when self-ligated, this fragment existed as an independent replicon (pfm011) and contained a 2.6-kilobase ecori-xbai fragment encoding nisin resistance. | 1988 | 2845861 |
| reconstitution of phosphate-linked antiport from streptococcus lactis. | membrane protein solubilized by octyl-beta-d-glucopyranoside in the presence of dispersed phospholipid was incubated with bath-sonicated liposomes and additional detergent. the proteoliposomes formed on dilution showed transport and exchange properties consistent with a reconstitution of phosphate:sugar 6-phosphate antiport. thus, phosphate self-exchange was found only when protein from induced cells was used; this exchange was blocked by a sugar 6-phosphate, not by a sugar 1-phosphate; and prot ... | 1985 | 2990460 |
| cloning and expression of a streptococcus cremoris proteinase in bacillus subtilis and streptococcus lactis. | previously, curing experiments suggested that plasmid pwv05 (17.5 megadaltons [md]) of streptococcus cremoris wg2 specifies proteolytic activity. a restriction enzyme map of pwv05 was constructed, the entire plasmid was subcloned in escherichia coli with plasmids pbr329 and pacyc184. a 4.3-md hindiii fragment could not be cloned in an uninterrupted way in e. coli but could be cloned in two parts. both fragments showed homology with the 9-md proteinase plasmid of s. cremoris hp. the 4.3-md hindii ... | 1985 | 2992377 |
| the cytochrome c oxidase test for the rapid detection of psychrotrophic bacteria in milk. | a new, rapid, simple and cheap method for the detection of the predominant psychrotrophic bacteria in raw and pasteurized milks is described, using tetramethyl-p-phenylene-diamine dihydrochloride to detect cytochrome c oxidase which in general is not present in the non-psychrotrophic bacterial milk flora. the test is sensitive to samples containing over 10(4) organisms/ml. correlation coefficients of 0.92 and 0.84 between dye oxidation and viable counts for pasteurized and raw milk samples, resp ... | 1985 | 2995302 |
| construction of cloning, promoter-screening, and terminator-screening shuttle vectors for bacillus subtilis and streptococcus lactis. | shuttle vectors have been constructed which are suitable both for the selection of regulatory sequences and for gene cloning in bacillus subtilis and streptococcus lactis. the promoter screening vectors contain a promoterless chloramphenicol acetyltransferase gene; the insertion of suitable dna fragments upstream of the gene restored the enzyme activity. with a related set of vectors, transcription termination signals can be selected. | 1985 | 2996425 |
| characterization of streptococcal bacteriophage c6a. | bacteriophage c6a is a lytic phage that infects strains of streptococcus lactis. infection of s. lactis c6 under standard conditions yielded 124 +/- 8 p.f.u. per infected cell after a latent period of 25 min at 30 degrees c. the virion of c6a was shown to contain at least 12 polypeptides and a 21.9 kilobase double-stranded, linear dna genome with complementary 5'-protruding single-stranded termini. the (g + c) content of this dna was estimated to be 36.7%. a restriction map was constructed which ... | 1985 | 2999317 |
| variable stoichiometry of phosphate-linked anion exchange in streptococcus lactis: implications for the mechanism of sugar phosphate transport by bacteria. | phosphate/2-deoxyglucose 6-phosphate antiport in streptococcus lactis showed an exchange stoichiometry that varied over a 2-fold range when assay ph was shifted between ph 8.2 and ph 5.2. at ph 7.0 and above, 2 mol of phosphate moved per mol of sugar phosphate; at ph 6.1 the ratio was 1.5:1, while at ph 5.2 the overall stoichiometry fell to 1.1:1. this pattern was not affected by valinomycin in potassium-based media, nor could variable stoichiometry be attributed to altered hydrolysis of the sug ... | 1986 | 3001731 |
| cloning in streptococcus lactis of plasmid-mediated uv resistance and effect on prophage stability. | plasmid pil7 (33 kilobases) from streptococcus lactis enhances uv resistance and prophage stability. a 5.4-kilobase pil7 fragment carrying genes coding for both characters was cloned into s. lactis, using plasmid phv1301 as the cloning vector. the recombinant plasmid was subsequently transferred to three other s. lactis strains by transformation or protoplast fusion. cloned genes were expressed in all tested strains. | 1986 | 3006588 |
| restriction enzyme analysis of lactose and bacteriocin plasmids from streptococcus lactis subsp. diacetylactis wm4 and cloning of bcli fragments coding for bacteriocin production. | the 131.1-kilobase (kb) bacteriocin production (bac) plasmid pnp2 and the 63.6-kb lactose metabolism (lac) plasmid pcs26, from streptococcus lactis subsp. diacetylactis wm4, as well as pwn8, a 116.7-kb recombinant plasmid from a lac+ transconjugant, were analyzed with restriction enzymes to determine the origin of pwn8. plasmid pwn8 conferred a lac+ bac- phenotype, contained dna derived from pcs26 and pnp2, and, like pnp2, exhibited self-transmissibility (tra+). in cloning attempts, bac+ transfo ... | 1987 | 3038015 |
| partial characterization of the genetic basis for sucrose metabolism and nisin production in streptococcus lactis. | we attempted to identify the genetic loci for sucrose-fermenting ability (suc+), nisin-producing ability (nip+), and nisin resistance (nisr) in certain strains of streptococcus lactis. to obtain genetic evidence linking the suc+ nip+ nisr phenotype to a distinct plasmid, both conjugal transfer and transformation were attempted. a conjugation procedure modified to protect the recipients against the inhibitory action of nisin allowed the conjugal transfer of the suc+ nip+ nisr marker from three su ... | 1986 | 3082279 |
| cloning, expression and location of the streptococcus lactis gene for phospho-beta-d-galactosidase. | genes for lactose catabolism and proteinase production in streptococcus lactis 712 are encoded by a 56.5 kb metabolic plasmid, plp712. a lactose mini-plasmid of only 23.7 kb, pmg820, was constructed by introducing two deletions into plp712, and was cloned as two segments of dna into the escherichia coli vector pat153 using restriction endonuclease psti. the lactose genetic region of plp712, which has been defined by deletion and restriction mapping, was cut into two parts by this process. when t ... | 1986 | 3086494 |
| anion exchange in bacteria: reconstitution of phosphate: hexose 6-phosphate antiport from streptococcus lactis. | | 1986 | 3086669 |
| [3-component nutrient medium for the nisin producer streptococcus lactis strain mgu]. | the methods of mathematical desing of experiments such as box and full factorial design were used in the study. as a result a three-component medium including 1-2 per cent of mollases, 10-20 mg% of yeast autolysate and 1-2 per cent of kh2po4 was recommended for biosynthesis of nisin. | 1986 | 3089136 |
| n5-(1-carboxyethyl)-ornithine, a new amino acid from the intracellular pool of streptococcus lactis. | intracellular concentrations of amino acids were determined in cells of streptococcus lactis 133 during growth in complex, spent, and chemically defined media. glutamic and aspartic acids represented the major constituents of the amino acid pool. however, organisms grown in spent medium or in defined medium supplemented with ornithine also contained unusually high levels of two additional amino acids. one of these amino acids was ornithine. the second compound exhibited properties of a neutral a ... | 1986 | 3090017 |
| bacterial anion exchange. use of osmolytes during solubilization and reconstitution of phosphate-linked antiport from streptococcus lactis. | membranes of streptococcus lactis were solubilized with 1.1% octyl-beta-d-glucopyranoside in the presence of 0.37% acetone/ether-washed phospholipid from several sources. after adding excess escherichia coli phospholipid as bath-sonicated liposomes, phosphate:sugar phosphate antiport was reconstituted in proteoliposomes by a 25-fold dilution in 0.1 m kpi (ph 7). assays of 32pi:pi exchange showed that antiport was subject to an inactivation which varied in severity according to the lipid present ... | 1986 | 3090028 |
| development of high-level streptomycin resistance affected by a plasmid in lactic streptococci. | some lactose-negative (lac-) mutants of streptococcus lactis c2 and ml3 exhibited development of very high level streptomycin resistance after incubation with subinhibitory concentrations of the drug for 18 to 22 h. these drug-resistant mutants showed no loss of resistance even after 6 months of subculturing in broth without any drug. the parental lac+ strains did not show mutation to high-level streptomycin resistance. the lac+ characteristic of the parental strain was conjugally transferred to ... | 1986 | 3092735 |
| high-efficiency transformation of streptococcus lactis protoplasts by plasmid dna. | streptococcus lactis il1403 protoplasts were transformed by plasmid pil204 (5.5 kilobases), which conferred erythromycin resistance with an average efficiency of 5 x 10(6) transformants per microgram of supercoiled dna. the procedure used and transformation efficiencies obtained were close to those described for bacillus subtilis (g. chang and s. n. cohen, mol. gen. genet. 168:111-115, 1979). | 1986 | 3092737 |
| resistance of streptococcus lactis mutants to beta-lactam antibiotics. | minimal inhibitory concentration and minimal bactericidal concentrations of penicillin and other beta-lactam antibiotics were determined for streptococcus lactis in milk and trypteine soy broth. the values were always higher in milk than in broth. minimal inhibitory concentration of penicillin was higher in solid than in liquid media. two mutants resistant to penicillin and other beta-lactam antibiotics were obtained, and their growth rate, proteolysis, and acidification patterns determined. tol ... | 1986 | 3093547 |
| reconstitution of atp-dependent calcium transport from streptococci. | membrane vesicles of three streptococcal strains (streptococcus faecalis, streptococcus lactis, and streptococcus sanguis) were extracted with octyl-beta-d-glucoside in the presence of escherichia coli lipid and glycerol. for reconstitution, the detergent extract was mixed with bath-sonicated e. coli lipid, in the presence of octyl-beta-d-glucoside, and proteoliposomes were formed by a 25-fold dilution. atp-dependent calcium accumulation by proteoliposomes was comparable to that found in parent ... | 1986 | 3096992 |
| influence of milk ultrafiltration on bacteriophages of lactic acid bacteria. | bacteriophages added to whole milk were partially concentrated during ultrafiltration. at 4:1 retentate, phage had concentrated 2.4:1. thermal destruction at 54 degrees c followed first order kinetics up to 6% protein, whereafter it deviated. when allowed to grow in retentate in the presence of appropriate host, 3.5 generations of phage appeared after 12 h at 22 degrees c compared with four generations in skim milk. in the presence of phage, lactic acid bacteria population increased to only 10(7 ... | 1986 | 3100588 |
| [nisin biosynthesis during the joint cultivation of streptococcus lactis strain mgu and yeasts]. | in simultaneous inoculation of the medium for nisin biosynthesis with streptococcus lactis (strain msu) and yeasts such as rhodotorula colostri, zigowilliopsis californicus, hansenuia anomala, saccharomyces ludvigii, kluyveromyces lactis and endomyces magnusi the quantitative ratio of the inoculates in the mixed cultures is not in principle important for the antibiotic synthesis by the streptococcus. when 6-, 12-, 18- and 24-hour inoculates of the yeasts were added simultaneously to 3-, 6-, 9-, ... | 1986 | 3101585 |
| [fusion of streptococcus lactis protoplasts]. | | 1987 | 3105436 |
| silver-coated nylon fiber as an antibacterial agent. | a blend of nylon fiber and silver-coated nylon fiber (the latter known as x-static) was used in these experiments. this fiber was bactericidal when bacteria were exposed to it directly or to an extract derived from its prior incubation in salt solution. at ambient temperatures, a rapid exponential decrease of survival occurred, usually after a delay of approximately 1 h. the rate of killing (decrease of survival) increased with an increase in x-static percentage of the fiber blend, temperature o ... | 1987 | 3105444 |
| conjugal transfer of nisin plasmid genes from streptococcus lactis 7962 to leuconostoc dextranicum 181. | acriflavine-generated mutants of streptococcus lactis 7962 with various combinations of plasmid molecular masses were screened for nisin production. nisin was produced by both the wild type and mutants that contained a 17.5-megadalton plasmid, which was obscured by chromosomal fragments. no nisin was produced by plasmid-free mutants. sucrose fermentation and nisin production were simultaneously expressed. a transconjugant obtained from nisin-producing donor s. lactis 7962 and recipient leuconost ... | 1987 | 3105456 |
| regulation of the glutamate-glutamine transport system by intracellular ph in streptococcus lactis. | various methods of manipulation of the intracellular ph in streptococcus lactis result in a unique relationship between the rate of glutamate and glutamine transport and the cytoplasmic ph. the initial rate of glutamate uptake by s. lactis cells increases more than 30-fold when the intracellular ph is raised from 6.0 to 7.4. a further increase of the cytoplasmic ph to 8.0 was without effect on transport. the different levels of inhibition of glutamate and glutamine transport at various external ... | 1987 | 3106334 |
| phage resistance in streptococcus lactis ssp. diacetylactis transconjugant sla3.2501 and its derivatives. | phage 18-16, which was virulent for streptococcus lactis ssp. diacetylactis sla3.25 was used to study phage-resistant characteristics of mucoid s. lactis ssp. diacetylactis transconjugant sla3.2501 obtained through conjugative cotransfer of psrq2201 (lac-plasmid) and psrq2202 (muc-plasmid) to sla3.25 (15). interaction of phage 18-16 with sla3.2501 and its derivatives showed that phage resistance was not related to either the lack of phage adsorption or restriction-modification. suppression of ph ... | 1987 | 3106443 |
| purification and characterization of a cell wall proteinase from streptococcus lactis ncdo 763. | a proteinase was purified from a cell wall extract of a culture of streptococcus lactis ncdo 763 grown in skim milk. being active at a low ph (at ph 4.8 on haemoglobin and ph 6.0-6.5 on casein) and completely inhibited by diisopropylfluorophosphate, it was considered to be a serine proteinase partly inhibited by edta; the mol. wt was approximately 80,000. | 1987 | 3110230 |
| calcium alginate-immobilized cultures of lactic streptococci are protected from bacteriophages. | calcium alginate-immobilized cultures of lactic streptococci were grown in milk and assessed for their sensitivity to homologous bacteriophage, proteolytic activity, and acid production. immobilized cultures of streptococcus lactis c2 and streptococcus cremoris hp were protected from attack by bacteriophage due to the exclusion of phage particles from the gel matrix. these cultures were also functionally proteinase-deficient when immobilized in calcium alginate beads and grown in milk. acid was ... | 1987 | 3112199 |
| proteolytic activity of lactic acid bacteria in skim milk with special reference to the biodegradation of casein fractions. | streptococci and lactobacilli were assayed for their proteolytic activity in pasteurised (95 degrees c for 30 min) fresh friesian cows' skim milk incubated at 30 degrees c for 48 h. lactobacilli were more proteolytic than the streptococci except s. faecalis subsp. liquefaciens. s. faecalis and s. thermophilus followed s. lactis subsp. diacetylactis in the proteolytic activity. electrophoretic analysis of the precipitated casein revealed k-, pre-beta- and the small slow band of alpha s1-casein to ... | 1987 | 3112574 |
| ornithine transport and exchange in streptococcus lactis. | resting cells of streptococcus lactis 133 appeared to accumulate [14c]ornithine to a high concentration in the absence of an exogenous energy source. however, analysis of intracellular amino acid pool constituents and results of transport experiments revealed that the accumulation of ornithine represented a homoexchange between extracellular [14c]ornithine and unlabeled ornithine in the cell. the energy-independent exchange of ornithine was not inhibited by proton-conducting uncouplers or by met ... | 1987 | 3114235 |
| [isolation of a mutant of streptococcus lactis resistant to penicillin]. | | 1987 | 3114857 |
| a method for genetic transformation of nonprotoplasted streptococcus lactis. | plasmid transformation of whole cells of streptococcus lactis lm0230 was demonstrated. the procedure required polyethylene glycol and incubation in hypertonic media, but did not require enzymatic cell wall digestion. conditions were optimized, yielding 5 x 10(5) transformants per micrograms of psa3 dna. variables tested for effect on transformation efficiency included molecular weight, concentration, and ph of polyethylene glycol; cell density; plating media; dna concentration; heat shock; and i ... | 1987 | 3116931 |
| dependence of streptococcus lactis phosphate transport on internal phosphate concentration and internal ph. | uptake of phosphate by streptococcus lactis ml3 proceeds in the absence of a proton motive force, but requires the synthesis of atp by either arginine or lactose metabolism. the appearance of free pi internally in arginine-metabolizing cells corresponded quantitatively with the disappearance of extracellular phosphate. phosphate transport was essentially unidirectional, and phosphate concentration gradients of up to 10(5) could be established. substrate specificity studies of the transport syste ... | 1987 | 3119562 |
| regulation of arginine-ornithine exchange and the arginine deiminase pathway in streptococcus lactis. | streptococcus lactis metabolizes arginine by the arginine deiminase (adi) pathway. resting cells of s. lactis grown in the presence of galactose and arginine maintain a high intracellular ornithine pool in the absence of arginine and other exogenous energy sources. addition of arginine results in a rapid release of ornithine concomitant with the uptake of arginine. subsequent arginine metabolism results intracellularly in high citrulline and low ornithine pools. arginine-ornithine exchange was s ... | 1987 | 3119567 |
| biosynthesis and stereochemical configuration of n5-(1-carboxyethyl)ornithine. an unusual amino acid produced by streptococcus lactis. | in a recent communication (thompson, j., curtis, m. a., and miller, s.p.f. (1986) j. bacteriol. 167, 522-529) we described the purification and characterization of n5-(1-carboxyethyl)ornithine from cells of streptococcus lactis 133. this unusual amino acid has not previously been found in nature. radiotracer experiments presented here reveal that exogenous [14c]ornithine serves as the precursor for biosynthesis of [14c]arginine, [14c]n5-(1-carboxyethyl)ornithine, and [14c]n5-acetylornithine by c ... | 1987 | 3119585 |
| spontaneous release of temperate phage by relysogenized lactose-positive transductants of streptococcus lactis c2. | transduction for lactose-fermenting ability between the lactose-positive lysogen streptococcus lactis lm0221 and plasmid-cured, prophage-cured, lactose-negative s. lactis lm2301 resulted in the appearance of lactose-positive transductants surrounded by a zone of clearing in the lactose-negative cell lawn. by using plaque assay procedures, the zones were shown to contain bacteriophage particles, and both spontaneous release and uv induction of prophage from these transductants were demonstrated. ... | 1987 | 3119683 |
| conjugative mobilization as an alternative vector delivery system for lactic streptococci. | due to the current variability in applying polyethylene glycol-mediated protoplast transformation to lactic streptococci, a study was undertaken to assess the feasibility of conjugative mobilization as an alternative method for vector delivery. by using the broad-host-range conjugative plasmid pva797, the partially homologous cloning vector pva838 was successfully introduced into various strains of streptococcus lactis, streptococcus cremoris, streptococcus lactis subsp. diacetylactis, streptoco ... | 1987 | 3122654 |
| conjugal transfer of plasmid pam beta 1 in lactobacillus reuteri and between lactobacilli and enterococcus faecalis. | the broad-host-range plasmid pam beta 1 (erythromycin resistance) was transferred conjugally from streptococcus lactis to lactobacillus reuteri, l. murinus, and l. fermentum. transfer of pam beta 1 between two l. reuteri strains occurred, and lactobacillus transconjugants could act as donors of pam beta 1 in crosses with enterococcus faecalis jh2-2. | 1987 | 3122658 |
| relation of growth of streptococcus lactis and streptococcus cremoris to amino acid transport. | the maximum specific growth rate of streptococcus lactis and streptococcus cremoris on synthetic medium containing glutamate but no glutamine decreases rapidly above ph 7. growth of these organisms is extended to ph values in excess of 8 in the presence of glutamine. these results can be explained by the kinetic properties of glutamate and glutamine transport (b. poolman, e. j. smid, and w. n. konings, j. bacteriol. 169:2755-2761, 1987). at alkaline ph the rate of growth in the absence of glutam ... | 1988 | 3123462 |
| n6-(1-carboxyethyl)lysine formation by streptococcus lactis. purification, synthesis, and stereochemical structure. | during growth in an arginine-deficient (chemically defined) medium, cells of streptococcus lactis k1 formed significant amounts of a previously undetected ninhydrin-positive compound. this intracellular compound did not cochromatograph with any of a wide range of amino acids or amino acid analogs tested. however, by two-dimensional thin layer chromatography, the unknown compound migrated close to the recently discovered n5-(1-carboxyethyl)ornithine (thompson, j., curtis, m. a., and miller, s. p. ... | 1988 | 3123486 |
| integration of bioconversions and downstream processing. some model studies. | | 1987 | 3124693 |
| [ir spectrophotometric study of a mixed culture of streptococcus lactis, strain msu, and rhodotorula colostri with agitation of the medium]. | physiological aspects of streptococcus lactis, strain msu development in mixed culture with rhodotorula colostri were studied in connection with nisin biosynthesis. by the ir spectra the average content of the main components in the monoculture cells of s. lactis and its association with the yeast in the stationary growth phase was the following by dry weight: 54-58 per cent of protein, 14-16 per cent of nucleic acids, 26-28 per cent of carbohydrates and 3-5 per cent of lipids. glucose and nitro ... | 1987 | 3124724 |
| molecular characterization and comparison of 38 virulent and temperate bacteriophages of streptococcus lactis. | thirty-three virulent and five temperate phages of streptococcus lactis and streptococcus cremoris were differentiated into three groups by dna homology. a complete lack of dna homology was demonstrated between the phage groups. within each group, large parts of the phage genomes were homologous except for a few phages. one group consisted of five temperate and two virulent phages suggesting that virulent phages isolated during abnormal fermentations and temperate phages isolated after induction ... | 1987 | 3128635 |
| isolation and structural analysis of the phospho-beta-galactosidase gene from streptococcus lactis z268. | a 4.4-kb xhoi fragment of streptococcus lactis l13 (z268) lactose plasmid pucl13, containing the beta-d-phosphogalactoside galactohydrolase (p-beta gal; ec 3.2.1.85)-coding gene has been cloned in escherichia coli. further subcloning and deletion of this fragment allowed localization of the p-beta gal-coding gene (pbg) on a minimal 1.8-kb segment. expression of p-beta gal activity was constitutive and was not regulated by glucose in e. coli. the presence of p-beta gal activity was correlated wit ... | 1988 | 3130294 |
| [use of the method of protoplast fusion in the selection of a nisin producer]. | experimental data on selection of streptococcus lactis producing the polypeptide antibiotic nisin with the method of protoplast fusing, one of the modern methods of cell engineering are presented. four strains of streptococcus lactis differing in their nisin-producing levels and difficult for protoplasting were used in the study. it was shown possible to transfer them to the protoplast form when respective conditions for their preliminary cultivation and regeneration are provided. distinctive fe ... | 1988 | 3132118 |
| plasmid-mediated reduced phage sensitivity in streptococcus lactis kr5. | the phage insensitivity of streptococcus lactis kr5 was evaluated for its possible linkage to plasmid dna. this strain possessed plasmids of 40, 29, 26, 21, 16.5, 10.5, 7.8, and 1.5 mdal. plasmid curing using novobiocin resulted in derivatives with increased sensitivity to prolate-headed phage, suggesting the involvement of plasmid dna in phage insensitivity. transformation of s. lactis lm0230 protoplasts with the kr5 plasmid dna pool produced transformants containing a plasmid of about 27 mdal. ... | 1988 | 3132485 |
| viability and metabolic capability are maintained by escherichia coli, pseudomonas aeruginosa, and streptococcus lactis at very low adenylate energy charge. | metabolic regulation by nucleotides has been examined in several bacteria within the context of the adenylate energy charge (ec) concept. the ecs of bacteria capable of only fermentative metabolism (streptococcus lactis and the atpase-less mutant escherichia coli an718) fell to less than 0.2 under carbon-limiting conditions, but the bacteria were able to step up the ec to greater than 0.8 upon exposure to nutrient sugars. similarly, nongrowing e. coli 25922, whose ec had been artificially lowere ... | 1988 | 3136145 |
| mutagenesis in streptococcus lactis exposed to uv irradiation and alkylating agents. | the lethal and mutagenic effects of various mutagens on three strains of streptococcus lactis were investigated. lethality studies demonstrated that s. lactis was relatively sensitive to uv irradiation, methyl methanesulphonate (mms) and n-methyl-n'-nitro-n-nitrosoguanidine (mnng), and, to a lesser extent, to ethyl methanesulphonate (ems). a spontaneous derivative lac-, which has lost a 37-md plasmid, was slightly more resistant and much less mutable than the wild-type after uv irradiation. alth ... | 1988 | 3137421 |
| cloning and expression of an alpha-acetolactate decarboxylase gene from streptococcus lactis subsp. diacetylactis in escherichia coli. | the streptococcus lactis gene coding for alpha-acetolactate decarboxylase (adc) was cloned in escherichia coli. subsequent subcloning in e. coli showed that the adc gene was located within a 1.3-kilobase dna fragment. the adc gene was controlled by its own promoter. gas chromatography showed that s. lactis and the transformed e. coli strains produced the two optical isomers of acetoin in different ratios. | 1988 | 3137872 |
| molecular taxonomy and phylogenetic position of lactic acid bacteria. | lactic acid bacteria, important in food technology, are gram-positive organisms exhibiting a dna g + c content of less than 50 mol%. phylogenetically they are members of the clostridium-bacillus subdivision of gram-positive eubacteria. lactobacillus and streptococci together with related facultatively anaerobic taxa evolved as individual lines of descent about 1.5-2 billion years ago when the earth passed from an anaerobic to an aerobic environment. in contrast to the traditional, morphology-bas ... | 1988 | 3139049 |
| present state of lactic acid bacteria phage taxonomy. | recent developments in molecular taxonomy of bacteriophages of lactobacilli and lactic streptococci are presented. dna homology appears to be the most valid criterion in studying phage taxonomy. for each bacterial species, phages can be classified in a few families according to this criterion. a fair correspondence is observed between the groups differentiated by dna-dna hybridization and those differenciated by protein composition. in 2 bacterial species, a close relatedness between some virule ... | 1988 | 3139058 |
| plasmid-encoded functions of ropy lactic acid streptococcal strains from scandinavian fermented milk. | ropy streptococcus (lactococcus) cremoris strains isolated from a ropy swedish sour milk ("longfil") and a ropy finnish milk product ("viili") were screened for their plasmid-encoded functions. curing experiments strongly indicated that the ropy phenotype was linked to a 17-md plasmid in the swedish strains and to a 30 md plasmid in the finnish strains. comparative restriction endonuclease analysis and dna/dna-hybridization studies revelated that plasmids from both strain families shared homolog ... | 1988 | 3139063 |
| identification of cell wall antigens associated with a large conjugative plasmid encoding phage resistance and lactose fermentation ability in lactic streptococci. | in order to begin to analyze the gene products encoded by phage resistance plasmids in lactic streptococci, we identified phage-resistance plasmids by screening resistant strains from commercial starter cultures for the ability to carry out unselected cotransfer, by conjugation, of phage resistance with lactose fermentation ability (lac+). in this fashion, we identified a large (90 kilobases) plasmid, pclp51r, that encodes the lac+ marker, resistance to a lytic phage called lp10g (1pr+), high-fr ... | 1988 | 3139064 |
| loss of phage resistance encoded by plasmid psk112 in chemostat cultures of lactococcus lactis ssp. cremoris sk110. | in cultures of l. lactis ssp. cremoris sk110, phage sk11g-resistant through the presence of psk112, phage-sensitive variants segregated spontaneously that lacked the plasmid. in overnight batch culture these comprised up to 1% of the total population. upon prolonged incubation in chemostat culture, a further loss of resistance was observed after a lag period. at high growth rates (0.7 h-1) this period amounted to approximately 35 generations, whereas cultures grown at rates of 0.4 and 0.1 h-1 re ... | 1988 | 3139065 |
| lactic acid bacteria ii. genetics and genetic exchange systems. | | 1988 | 3139066 |
| molecular cloning of lactose genes in dairy lactic streptococci: the phospho-beta-galactosidase and beta-galactosidase genes and their expression products. | the mesophilic (s. lactis and s. cremoris) and thermophilic (s. thermophilus) dairy lactic streptococci, which are used in industrial dairy fermentations, contain two different lactose hydrolysing enzymes, a phospho-beta-galactosidase and a beta-galactosidase. the central role of these enzymes in the pathways used for lactose transport and degradation is discussed along with their properties and distributions in lactic streptococci. in addition, recent results on the cloning, expression and sequ ... | 1988 | 3139067 |
| genetics of proteinases of lactic acid bacteria. | because it is essential for good growth with concomitant rapid acid production, and for the production of flavorous peptides and amino acids, the proteolytic ability of lactic acid bacteria is of crucial importance for reliable dairy product quality. in view of this importance, considerable research has been carried out to characterize the enzymes involved. the intensified genetic research in the lactic acid streptococci and the development of gene cloning systems for these organisms have result ... | 1988 | 3139068 |
| new nomenclature of the non-rod-shaped lactic acid bacteria. | bacteria of the lactococcus (formerly lactic streptococcus) genus are described to emphasize certain less well-known facts of importance in their successful use as dairy starters. other streptococci (non-rod forms) are briefly characterized to emphasize their usefulness in industrial milk fermentations. | 1988 | 3139070 |
| characterization of a cloned chromosomal fragment affecting the proteinase activity of streptococcus lactis ssp. lactis. | plasmid pvs8 (14.3 kbp) contains a 9.3 kbp fragment of streptococcus lactis ssp. lactis ssl135 chromosomal dna associated with the ability of this strain to grow in milk. in this study, it was found that pvs8 complements a defective plasmid-linked proteinase gene of ssl135. using deletions and insertions, it was found that the size of the complementing region of pvs8 is approximately 6.0 kbp, and that its main part is located within a 5.7 kbp bglii fragment. | 1988 | 3139072 |
| utilization of dipeptides by lactococcus lactis ssp. cremoris. | different strains of lactococcus lactis ssp. cremoris hydrolyze peptides at different rates while the cell-free extracts of these strains all show the same or much higher rates of hydrolysis. these observations indicate that the uptake of peptides is the rate-limiting step in peptide hydrolysis. utilization of leucyl-leucine by non-growing cells is competitively inhibited by the structurally related dipeptide alanyl-alanine. after hydrolysis of peptides, the amino acids are released into the med ... | 1988 | 3139073 |
| antitumor activity of lactic acid bacteria on a solid fibrosarcoma, sarcoma-180 and ehrlich ascites carcinoma. | antitumor activity of leuconostoc mesenteroides, streptococcus cremoris and streptococcus lactis was investigated in solid mouse fibrosarcoma. intratumor administration of lyophilised bacterial cells at a dose of 20 mg/kg body wt resulted in the regression of tumors in a maximum number of animals. intraperitoneal injection at the same dose resulted in a significant increase in the survival time but was ineffective in curing the animals. intratumor injection of streptococcus thermophilus at a dos ... | 1988 | 3141041 |
| structure, expression, and evolution of a gene encoding the precursor of nisin, a small protein antibiotic. | we have cloned and sequenced a gene (span) from streptococcus lactis atcc 11454 which encodes the peptide precursor of the small protein antibiotic nisin. the encoded precursor is 57 amino acids long, with a 23-residue leader region and a 34-residue structural region. the structural region contains serines, threonines, and cysteines at exactly the positions required to give mature nisin by a series of post-translational modifications involving dehydration of serines and threonines to dehydro for ... | 1988 | 3141403 |
| biological and biochemical characterization of novel lipid-like antibacterial substances (mutalipocins) produced by streptoccus mutans strain 32k. | two novel antibacterial substances (designated mutalipocins) have been isolated from the culture supernatant of streptoccus mutans strain 32k (serotype c). the mutalipocins were purified by extraction of the culture supernatant with light petroleum (b.p. range 30-60 degrees c), followed by lobar column chromatography on lichroprep rp-8. hplc indicated that both mutalipocin preparations (ml-i and ml-ii) were homogeneous. the mr values of ml-i and ml-ii were less than 1000. both mutalipocins were ... | 1988 | 3141562 |
| evidence for the conjugal transfer of the broad host range plasmid pip501 into strains of lactobacillus helveticus. | the conjugative broad host range plasmid pip501 was transferred from streptococcus faecalis to a series of strains of lactic streptococci used commercially as dairy starter cultures. with these transconjugants as donors the plasmid was exconjugated to two strains of lactobacillus helveticus and a commercially used strain of strep. thermophilus. there was evidence that the plasmid could transfer between isogenic derivatives of one of the strains of lact. helveticus. transfer from lact. helveticus ... | 1988 | 3146566 |
| proteolysis and electrophoretic pattern of casein of some fermented milks. | proteolysis and electrophoretic pattern of casein were determined in friesian cows' skim milk, buffaloes' skim milk and in these milks fermented spontaneously (leben rayeb) and by streptococcus lactis subsp. diacetylactis drc3 (nonfat buttermilk) or by zabadi starter (zabadi). the highest proteolysis, as evidenced by the amount of released leucine, occurred in zabadi and the lowest in leben rayeb. the highest amount of tyrosine was liberated in the nonfat buttermilk. proteolysis seems not to dep ... | 1988 | 3148111 |
| [effect of amino acids on the growth of the lactic acid streptococci streptococcus lactis and the process of their protoplast formation]. | | 1988 | 3149656 |
| influence of lactic starter inoculation, curd heating and ripening temperature on staphylococcus aureus behaviour in manchego cheese. | growth and survival of staphylococcus aureus were investigated in 52 lots of raw ewe's milk manchego cheese manufactured and ripened under different conditions. a 5.8-fold reduction in s. aureus counts after 60 days of ripening was obtained by inoculating milk with 1% streptococcus lactis culture, and a further 2.0-fold reduction could be achieved by adding 0.1% lactobacillus plantarum culture. curd heating temperature had a significant effect on s. aureus survival, with counts 4-5 times lower i ... | 1988 | 3152798 |
| application of electroporation for transfer of plasmid dna to lactobacillus, lactococcus, leuconostoc, listeria, pediococcus, bacillus, staphylococcus, enterococcus and propionibacterium. | plasmid dna was introduced by electroporation into bacillus, enterococcus, lactobacillus, lactococcus, leuconostoc, listeria, pediococcus, propionibacterium and staphylococcus as an alternative to competent-cell or protoplast transformation. plasmid-containing transformants were recovered in these recipients at frequencies ranging from 10(1) to 10(5) transformants micrograms-1 of pgk12. several parameters of the protocol, including dna concentration, voltage, plating regimen and electroporation ... | 1988 | 3185282 |
| cell surface proteins of encapsulated streptococcus cremoris: identification and immunochemical characterization. | cell surface proteins of two slime-forming, encapsulated streptococcus cremoris strains, mls96 and t5 from the fermented milk product viili, were extracted with the non-ionic detergent triton x-100. the isolated protein antigens were characterized by sodium dodecyl sulphate polyacrylamide gel electrophoresis and immunoblotting with antisera produced against whole strep. cremoris cells. when protein profiles of these strains were compared, seven prominent polypeptides were found common to both an ... | 1987 | 3654403 |
| kinetics of activation of l-lactate dehydrogenase from streptococcus lactis by fructose 1,6-bisphosphate. | a lag is observed before the steady state during pyruvate reduction catalysed by lactate dehydrogenase from streptococcus lactis. the lag is abolished by preincubation of enzyme with the activator fructose 1,6-bisphosphate before mixing with the substrates. the rate constants for the lag phase showed a linear dependence on fructose-1,6-bisphosphate concentration, with a second-order rate constant of 2.0 x 10(4) m-1 s-1, but were independent of enzyme concentration. binding of fructose 1,6-bispho ... | 1985 | 3917918 |
| interaction between streptococcus lactis and aspergillus flavus on production of aflatoxin. | the inoculation of aspergillus flavus spores into a culture of streptococcus lactis in lablemco tryptone broth medium resulted in little or no aflatoxin accumulation even though the growth of the fungus was not hindered. the drop in ph and reduced nutrient levels in the medium as a result of the s. lactis growth were not the cause of the observed inhibition. the inhibition was not eliminated by the addition of carbohydrate equal to the amount used by the bacterium before the inoculation with the ... | 1985 | 3919639 |
| lactose metabolism in streptococcus lactis: studies with a mutant lacking glucokinase and mannose-phosphotransferase activities. | a mutant of streptococcus lactis 133 has been isolated that lacks both glucokinase and phosphoenolpyruvate-dependent mannose-phosphotransferase (mannose-pts) activities. the double mutant s. lactis 133 mannose-ptsd gk- is unable to utilize either exogenously supplied or intracellularly generated glucose for growth. fluorographic analyses of metabolites formed during the metabolism of [14c]lactose labeled specifically in the glucose or galactosyl moiety established that the cells were unable to p ... | 1985 | 3920203 |
| intracellular phosphorylation of glucose analogs via the phosphoenolpyruvate: mannose-phosphotransferase system in streptococcus lactis. | the bacterial phosphoenolpyruvate:sugar-phosphotransferase system (pts) mediates the vectorial translocation and concomitant phosphorylation of sugars. the question arises of whether the pts can also mediate the phosphorylation of intracellular sugars. to investigate this possibility in streptococcus lactis 133, lactose derivatives have been prepared containing 14c-labeled 2-deoxy-glucose (2dg), 2-deoxy-2-fluoro-d-glucose (2fg), or alpha-methylglucoside as the aglycon substituent of the disaccha ... | 1985 | 3920204 |
| lysin production by phi c2(w), a prolate phage for streptococcus lactis c2. | a bacteriophage, phi c2(w), which attacked streptococcus lactis strains c2, ml3 and 712, is described. it had a prolate head and non-contractile tail and produced large haloes around plaques. infection of eight paired-strain cultures, each containing str. lactis c2, with phi c2(w) resulted in marked inhibition of acid production for six cultures. direct phage-nonhomologous "host' contact was not required for inhibition. lysates of phi c2(w) contained a phage-induced lysin. evidence is presented ... | 1985 | 3921575 |
| partial purification and some properties of phi c2(w) lysin, a lytic enzyme produced by phage-infected cells of streptococcus lactis c2. | the lytic enzyme present in phi c2(w) lysates was isolated by means of ion-exchange chromatography and further purified by gel filtration and ultrafiltration. the phage enzyme had an apparent ph optimum of 6.5-6.9 and was rapidly inactivated at temperatures greater than 47 degrees c. the apparent temperature optimum was 37 degrees c and q10 and ea values over the range 22-32 degrees c were 2.5 and 69.2 kj/mol respectively. monovalent and divalent cations activated the enzyme. reduced -sh groups ... | 1985 | 3921576 |
| adaptation of lactic streptococci for growth with their homologous bacteriophage. | the adaptation of lactic streptococci for growth with their homologous bacteriophage was studied through the addition of bacteriophage filtrate to skim milk medium inoculated with streptococcus lactis or streptococcus cremoris. both s. lactis and s. cremoris attained their adaptability for growth with their homologous bacteriophage after 5 and 2 transferes, respectively, and did not lose it after a storage period of 30 days at 0 degree c. | 1985 | 3921846 |
| survey of antimicrobial resistance in lactic streptococci. | a total of 26 strains of streptococcus cremoris and 12 strains of streptococcus lactis were challenged with 18 antimicrobial agents and with nisin in the bauer-kirby disk susceptibility test. all strains were susceptible to ampicillin, bacitracin, cephalothin, chloramphenicol, chlortetracycline, erythromycin, penicillin g, tetracycline, and vancomycin. all strains were resistant to trimethoprim, and almost all strains were resistant to sulfathiazole. variability in resistance to gentamicin, kana ... | 1985 | 3922298 |
| [joint cultivation of streptococcus lactis, lmu strain, and various species of yeasts]. | when s. lactis, strain lmu and yeast were plated out simultaneously on media containing different amounts of amine nitrogen and vitamins, the yeast did not stimulate the synthesis of nisin. plating out of s. lactis on media with grown cultures of the rostov baker's yeast, american baker's yeast, candida guilliermondii, candida clausenii, fabospora fragilis, fabospora macedoniensis, octosporomyces octosporus, saccharomyces cerevisiae, races "ya" and "m" and saccharomyces globosus resulted in inhi ... | 1985 | 3923918 |
| comparative peptide specificity of cell wall, membrane and intracellular peptidases of group n streptococci. | solubilized cell walls of group n streptococci contain two electrophoretically distinct peptidases, one of which hydrolysed trileucine only, while the second hydrolysed a wide range of di- and tripeptides. neither enzyme possessed leucine aminopeptidase or endopeptidase activity. four and three peptidases, respectively, were separated in intracellular extracts of streptococcus lactis subsp. lactis and strep. lactis subsp. cremoris produced by osmotic lysis of spheroplasts. in contrast with the c ... | 1985 | 3924874 |
| the bacterial phosphoenolpyruvate-dependent phosphotransferase system. isolation of active site peptides by reversed-phase high-performance liquid chromatography and determination of their primary structure. | using reversed-phase high-performance liquid chromatography (hplc) it was possible to isolate 32p-labelled active-site regions of various proteins from the bacterial phosphoenolpyruvate-dependent phosphotransferase system. the purified peptides obtained by proteolytic cleavage with lys-c protease and trypsin were sequenced by the gas phase method. the fragments derived from enzyme i (mw 70 000) of two streptococcal species show 100% homology. the analogous peptide of staphylococcus aureus enzyme ... | 1985 | 3928666 |
| conjugal transfer from streptococcus lactis me2 of plasmids encoding phage resistance, nisin resistance and lactose-fermenting ability: evidence for a high-frequency conjugative plasmid responsible for abortive infection of virulent bacteriophage. | streptococcus lactis me2 exhibits at least three mechanisms which confer resistance to virulent bacteriophage. these include plasmid-induced interference with phage adsorption, host-controlled restriction and modification activities, and a heat-sensitive mechanism which suppresses development of virulent phage. conjugal mating experiments were done with s. lactis me2 to determine if phage-defence mechanisms present in this strain could be mobilized, associated with plasmid dna elements and pheno ... | 1985 | 3930657 |
| malachite green pre-enrichment medium for improved salmonella isolation from heavily contaminated samples. | large numbers of competitive bacteria may hinder the isolation of salmonellas from food and environmental samples when a pre-enrichment method is used. the addition of 0.1 g/l of malachite green (mg) to buffered peptone water (bpw) inhibited the multiplication of gram-positive bacteria. brilliant green had a similar effect but only when the normal recommended concentration of 0.02 g/l was raised to 0.05 g/l. pure strains of salmonellas were inhibited by mg in bpw, but addition of non fat dried m ... | 1985 | 3932291 |
| secretory and serum antibodies against streptococcus lactis, streptococcus thermophilus, and lactobacillus bulgaricus in relation to ingestion of fermented milk products. | serum, saliva, and urine were analyzed for the presence of iga, igg, and igm antibodies reactive with the yoghurt bacteria streptococcus thermophilus and lactobacillus bulgaricus. a comparison was made between four subjects who frequently ate yoghurt and four subjects who never ate yoghurt. salivary iga and serum igg activity against the milk-fermenting bacterium s. lactis was studied in five other subjects before, during, and after a period of ingestion of a fermented milk product, filmjölk. al ... | 1985 | 3933276 |
| growth of lactic acid bacteria in highly concentrated ultrafiltered skim milk retentates. | buffer capacity of ultrafiltered skim milk retentates at various protein concentrations and growth of direct set, frozen concentrated lactic starter cultures in such retentates were studied. maximum buffering occurred at approximately ph 5.1 to 5.3. an average .48% lactic acid concentration was required to reduce the ph of plain skim milk to 4.6 compared with 1.01% for skim milk retentates concentrated 2.3:1 and 1.14% for skim milk retentate concentrated 2.6:1. skim milk retentates concentrated ... | 1985 | 3934241 |
| covalent modification of citrate lyase ligase from clostridium sphenoides by phosphorylation/dephosphorylation. | citrate lyase ligase was shown to be present in clostridium sphenoides actively degrading citrate. in contrast to citrate lyase ligase from c. sporosphaeroides and streptococcus lactis, the enzyme from c. sphenoides was under stringent regulatory control. the alteration of the kinetic properties of the enzyme after depletion of citrate suggested the presence of two different enzyme species in different phases of growth: active and partially active citrate lyase ligase. these enzymes were purifie ... | 1985 | 3935436 |
| [amino acid composition and biological value of koumiss leaven]. | to study the biological value of kumyss leaven, experiments were made with mono-cultures contained by kumyss leaven. the cultures streptococcus lactis, strain 1-27, lactobacillus bulgaricus, strain b-3, acetic acid bacteria and the yeast culture torulopsis kefir var kumis, strain 17 contained by kumyss leaven were employed as test objects. experiments were performed with defattened cow's milk. the following parameters were measured: acidity according to turner (t degree), dry residue, total nitr ... | 1985 | 3936275 |
| effect of ca2+ ions on plasmid transformation of streptococcus lactis protoplasts. | the effects of mg2+ and ca2+ ions on the efficiency of the plasmid transformation of lysozyme-treated streptococcus lactis protoplasts were compared. a 33-megadalton plasmid, plp712, coding for lactose fermentation and a 6.5-megadalton plasmid, pgb301, coding for erythromycin and chloramphenicol resistance were used as model plasmids, and s. lactis mg1614 was the recipient. replacing mg2+ with ca2+ in the transformation buffer was found to increase transformant frequency more than 10-fold with b ... | 1985 | 3936417 |
| [controlled clinical study on the therapeutic efficacy of enterococcus acidogenus hs 15 of human origin in diarrheic enterocolitis]. | | 1985 | 3937071 |
| anion exchange in bacteria. variable stoichiometry of phosphate: sugar 6-phosphate antiport. | | 1985 | 3937469 |
| bactericidal cationic peptides involved in bacterial antagonism and host defence. | there are numerous reports in the literature on small, strongly cationic peptides displaying marked antimicrobial activity. these peptides are produced by bacteria as well as higher organisms, and are thought to be involved in bacterial antagonism or host defence mechanisms. | 1985 | 3940149 |
| induction of prophage in streptococcus lactis c2 by ultraviolet irradiation. | streptococcus lactis c2 has been used extensively by many laboratories in studies on the metabolism of lactic streptococci. by using ultraviolet irradiation as the inducing agent, this organism was shown to release a small bacteriophage, indicating that it is a lysogenic strain. the induced phage had a head approximately 40 nm in diameter and a tail length and width of about 180 and 6 nm, respectively. a structure resembling a collar was observed. attempts to isolate a sensitive indicator strain ... | 1973 | 4121540 |
| morphology of the bacteriophages of lactic streptococci. | electron microscope studies have been made of a number of phages of lactic streptococci, seven of which were phages of streptococcus lactis c10. two of the phages are thought to be identical; five have been classified by the method of tikhonenko as belonging to group iv (phages with noncontractile tails) with type iii tail plates; one belongs to group v (phages with tails possessing a contractile sheath). both prolate polyhedral heads and isometric polyhedral heads are represented among the grou ... | 1974 | 4132690 |
| effect of aflatoxins on microorganisms. | | 1972 | 4197365 |