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microorganisms and characteristics of laban.laban had a titratable acidity of about 1.0%, a ph of 4.25, an ethanol content of 1.25%, and contained 4.2 mug acetaldehyde and 34 mug acetoin/ml. there was no diacetyl. five microorganisms, classified as streptococcus thermophilus, lactobacillus acidophilus, leuconostoc lactis, kluyveromyces fragilis, and saccharomyces cerevisiae, were responsible for the fermentation. streptococcus thermophilus and l. acidophilus were responsible for acid production with s. thermophilus producing acid more rap ...19762630
development and resistance of staphylococci in bulgaricus milk.studied was the dynamics of development of 9 strains of staphilococci isolated from humans and animals, kept in heat-treated milk, and their resistance in bulgarian sour milk. it was established that the pathogenic staph. aureus and staph. epidermidis develop will in fresh milk kept up to 7 days at 2--6degreesc and 18--22degreesc. in the production of bulgarian sour milk staph, aureus was shown to be viable, remaining active for seven days at 2 to 6degreesc. at room temperature (18--22degreesc) ...19767875
production of beta-galactosidase from streptococcus thermophilus grown in whey.beta-d-galactosidase (ec 3.2.1.23) was extracted from streptococcus thermophilus grown in deproteinized cheese whey. cultural conditions optimum for maximum enzyme production were ph 7.0, 40 degrees c, and 24 h. proteose peptone (2.0%, wt/vol) and corn steep liquor (2.8%, wt/vol) were highly stimulatory, increasing the enzyme units available in their absence from 660 u/liter of medium to 18,200 and 10,000 u/liter of medium, respectively, in their presence. there was an insignificant increase in ...197720840
[detection of inhibitory substances in milk using the modified reduction micromethod].in order to rationalize work and to reduce the consumption of laboratory glassware a reduction micromethod with the bacterial stain streptococcus thermophilus has been modified; the method is used to detect inhibitory substances in genuine, pausteurized and dried milk, and it is performed on a serological plate made from organic glass. the method is sensitive to most antibiotics used in the veterinary clinical practice. the detection sensitivity to penicillin residua ranges from 0.0015 to 0.0015 ...1978100933
differences in sensitivity to penicillin between strains of streptococcus thermophilus [proceedings]. 1979582898
lactate dehydrogenases of streptococcus thermophilus. 1978711959
binding of the fluorescent probes 1-anilinonaphthalene-8-sulfonate and n-phenyl-1-naphthylamine to bacteria.changes in fluorescence intensities in pseudomonas fluorescens, escherichia coli, streptococcus thermophilus, and bacillus subtilis were investigated by means of the fluorescence probes (1-anilinonaphthalene-8-sulfonate and n-phenyl-1-naphthylamine) during a temperature programmed run. a decrease in fluorescence intensity was observed in all investigated organisms when the temperature was elevated from 4 to about 40 degrees c. a strong increase in fluorescence intensity was found in gram-negativ ...1975811030
different bacteriophage resistance mechanisms in streptococcus salivarius subsp. thermophilus.streptococcus salivarius subsp. thermophilus strain nst5 exhibited a temperature-dependent defence mechanism against the virulent bacteriophages phi b1.2 and phi a1.1. it was active at 42 degrees c but not at 30 degrees c as demonstrated by a significant increase of both plaque size and efficiency of plaquing. this defence mechanism did not affect host-dependent phage replication and did not interfere with phage adsorption to nst5. these results suggest that it interfered with phage development. ...19921328335
the 23s-5s spacer of two rrna loci of streptococcus salivarius subsp thermophilus includes a promoter.the nucleotide sequence of the 3' part of a ribosomal and transfer rna locus from streptococcus salivarius subsp thermophilus nst1403 was determined. the sequenced dna fragment includes the 3' end of a 23s rrna gene, a 5s rrna gene, a trna(asn) gene and a potential transcriptional terminator. the trna gene does not encode for the cca 3'terminus of mature trna. we compared this sequence to a promoter-carrying dna fragment sequence (p20) of streptococcus salivarius subsp thermophilus a054 [1]. we ...19921381619
effects of bacterial inoculation of high-moisture ear corn on its aerobic stability, digestion, and utilization for growth by beef steers.high-moisture ear corn (hmec) was treated with specific bacterial inoculants and evaluated for its aerobic stability and utilization for growth by beef steers. immediately after harvest, hmec (65% dm) was ensiled in tower silos after being either untreated (control) or treated with the following inoculants: 1) ecosyl (e); 2) ecosyl plus serratia rubidaea (e + sr); and 3) ecosyl plus streptococcus thermophilus (e + st). a portion of hmec was frozen immediately (-20 degrees c) and subsequently tre ...19921429293
lactose transport system of streptococcus thermophilus. functional reconstitution of the protein and characterization of the kinetic mechanism of transport.the kinetic mechanism of the lactose transport system of streptococcus thermophilus was studied in membrane vesicles fused with cytochrome c oxidase containing liposomes and in proteoliposomes in which cytochrome c oxidase was coreconstituted with the lactose transport protein. selective manipulation of the components of the proton (and sodium) motive force indicated that both a membrane potential and a ph gradient could drive transport. the galactoside/proton stoichiometry was close to unity. e ...19921429561
cloning and sequencing of the melb gene encoding the melibiose permease of salmonella typhimurium lt2.the nucleotide sequence of the melb gene coding for the na+ (li+)/melibiose symporter of salmonella typhimurium lt2 was determined, and its amino acid sequence was deduced. it consists of 1428 bp, corresponding to a protein of 476 amino acid residues (calculated molecular weight 52,800). the amino acid sequence is homologous to that of the melibiose permease of escherichia coli k12, with 85% identical residues. all, except one, of the amino acid residues that have been reported to be important f ...19921495487
construction and characterization of shuttle plasmids for lactic acid bacteria and escherichia coli.the chimeric plasmid pbn183 was first constructed in escherichia coli by ligating the bamhi-digested e. coli plasmid pbr322 and a bg/ii-linearized streptococcal plasmid, pnz18. the pbn183 transformed e. coli to apr at a frequency of (8.2 +/- 1.2) x 10(5) colony forming units (cfu)/microgram dna. electrotransformation of streptococcus thermophilus with pbn183 yielded cmr, aps clones at a frequency of (2.6 +/- 0.3) x 10(1) cfu/microgram dna. plasmid screening with pbn183-transformed s. thermophilu ...19921518910
sequencing and characterization of pst1, a cryptic plasmid from streptococcus thermophilus.eighty-six strains of s. thermophilus were examined for their plasmid content. thirteen strains were found to contain one or two plasmids ranging in size from 2.1 to 7.4 kb. dna-dna hybridization analysis revealed the presence of five distinct groups of dna homology. the complete nucleotide sequence of plasmid pst1 (accession number x65856), which belongs to the major homology group, was determined. it has a molecular size of 2093 bp, a gc content of 35% and contains one major open reading frame ...19921526450
properties of aspartate racemase, a pyridoxal 5'-phosphate-independent amino acid racemase.aspartate racemase from streptococcus thermophilus contains no pyridoxal 5'-phosphate or other cofactors such as fad, nad+, and metal ions. it was affected by neither carbonyl reagents such as hydroxylamine nor sodium borohydride but was strongly inhibited by iodoacetamide and other thiol reagents. aspartate, cysteate, and cysteine sulfinate were the only substrates. the km values for l- and d-aspartate were 35 and 8.7 mm, respectively. the enzyme catalyzed the exchange of alpha-hydrogen of the ...19921526977
detection of propionic acid bacteria in cheese.mesophilic lactic starters and thermophilic lactobacilli but not streptococcus salivarius subsp. thermophilus grew on the sodium lactate agar (sla) used for estimating the numbers of propionic acid bacteria (pab) in cheese. the addition of cloxacillin (4 micrograms/ml) to sla inhibited the starter bacteria but had no effect on the pab. it was possible to count low numbers of pab in the presence of high numbers of starter bacteria. a correlation coefficient of 0.9 was obtained between the level o ...19921560128
evidence and characterization of temperate bacteriophage in streptococcus salivarius subsp. thermophilus st18.lysogenic strains of streptococcus salivarius subsp. thermophilus were studied using induction with mitomycin c (mc). the induction and presence of temperate phage were investigated carrying out tests on sensitive strains, electron microscopy and phage dna analysis. forty-five str. salivarius subsp. thermophilus strains were subjected to induction with mc and growth of the various cultures was evaluated. only one strain of those tested showed lysis after adding mc, thus indicating a possible lys ...19921560129
purification and partial characterization of an intracellular aminopeptidase from streptococcus salivarius subsp. thermophilus strain aca-dc 114.an intracellular aminopeptidase from streptococcus salivarius subsp. thermophilus strain aca-dc 114, isolated from traditional greek yoghurt, was purified by chromatography on deae-cellulose and sephadex g-100. the enzyme had a molecular weight of 89,000. it was active over a ph range 4.5-9.5 and had optimum activity on l-lysyl-4-nitroanilide at ph 6.5 and 35 degrees c with km = 1.80 mmol/l; above 55 degrees c the enzyme activity declined rapidly. the aminopeptidase was capable of degrading subs ...19921568949
lactose transport system of streptococcus thermophilus. the role of histidine residues.the lactose transport protein (lacs) of streptococcus thermophilus is a chimeric protein consisting of an amino-terminal carrier domain and a carboxyl-terminal phosphoenolpyruvate:sugar phosphotransferase system (pts) iia protein domain. the histidine residues of lacs were changed individually into glutamine or arginine residues. of the 11 histidine residues present in lacs, only the his-376 substitution in the carrier domain significantly affected sugar transport. the region around his-376 was ...19921577752
[clinical consequences of replacing milk with yogurt in persistent infantile diarrhea].persistent diarrhea is an episode of diarrhea that begins acutely but lasts longer than expected for this usually self-limited disease. treatment of this ill-defined syndrome is not well standardized but immediate intervention is required to minimize the risk of malnutrition with its various consequences. this randomized clinical trial was undertaken to evaluate the clinical efficacy of substituting yogurt for milk, as the only treatment. after a one to two-day observation period during which a ...19921580532
detection of intraspecific dna polymorphism in streptococcus salivarius subsp. thermophilus by a homologous rdna probe.three ribosomal probes from streptococcus salivarius subsp. thermophilus were cloned. sequence data demonstrate that their juxtaposition corresponds to an entire operon. they were used in order to study ribosomal operon number and organization. rrna genes were shown to be clustered in the order 5'-16s-23s-5s-3' and the number of rrn loci to vary within the subspecies. the smallest of the 3 probes was used for strain characterization. substantial variability in hybridization patterns was observed ...19921641511
a species-specific dna probe obtained from streptococcus salivarius subsp. thermophilus detects strain restriction polymorphism.genomic polymorphism in streptococcus salivarius subsp. thermophilus was revealed by dna restriction pattern analysis. a 4.2-kb variable dna fragment was cloned from strain nst7 and hybridised with the dna of 25 strains allowing an easy detection of intraspecific rflp. strong and weak hybridisation signals were observed and the latter were specifically revealed by a 2.1-kb fragment of the probe. probe specificity was demonstrated by the absence of homology with dna of strains belonging to 10 oth ...19911679405
carbohydrate utilization in streptococcus thermophilus: characterization of the genes for aldose 1-epimerase (mutarotase) and udpglucose 4-epimerase.the complete nucleotide sequences of the genes encoding aldose 1-epimerase (mutarotase) (galm) and udpglucose 4-epimerase (gale) and flanking regions of streptococcus thermophilus have been determined. both genes are located immediately upstream of the s. thermophilus lac operon. to facilitate the isolation of gale, a special polymerase chain reaction-based technique was used to amplify the region upstream of galm prior to cloning. the galm protein was homologous to the mutarotase of acinetobact ...19901694527
lactose metabolism in lactobacillus bulgaricus: analysis of the primary structure and expression of the genes involved.the genes coding for the lactose permease and beta-galactosidase, two proteins involved in the metabolism of lactose by lactobacillus bulgaricus, have been cloned, expressed, and found functional in escherichia coli. the nucleotide sequences of these genes and their flanking regions have been determined, showing the presence of two contiguous open reading frames (orfs). one of these orfs codes for the lactose permease gene, and the other codes for the beta-galactosidase gene. the lactose permeas ...19911705929
interferon induction by lactobacillus bulgaricus and streptococcus thermophilus in mice.this study investigates the effect of intraperitoneal injection of l. bulgaricus and s. thermophilus on interferon production by swiss mice. the serum from mice given 5 x 10(7) l. bulgaricus in 0.5 ml saline showed a maximal production of 300 u/ml of alpha/beta interferon activity six hours after injection. cellular integrity appears to be necessary for stimulation; heat-treated bacteria had little effect, while irradiated-bacteria had a greater effect. tnf was also produced, the sera of mice wi ...19911721851
purification and characterization of an endopeptidase from lactococcus lactis subsp. cremoris wg2.an endopeptidase has been purified to homogeneity from a crude cell extract of lactococcus lactis subsp. cremoris wg2 by a procedure that includes diethyl-aminoethane-sephacel chromatography, phenyl-sepharose chromatography, hydroxylapatite chromatography, and fast protein liquid chromatography over an anion-exchange column and a hydrophobic-interaction column. gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated a molecular mass of the purified enzyme of 70,000 ...19911785932
purification, properties, and sequence specificity of ssli, a new type ii restriction endonuclease from streptococcus salivarius subsp. thermophilus.ssli, a type ii restriction endonuclease, was purified from streptococcus salivarius subsp. thermophilus strain bsn 45. ssli is an isoschizomer of bstni. ssli activity was maximum at ph 8.8, 0 to 50 mm nacl, 2 to 8 mm mg2+, and 42 degrees c. activity against phage dna in vitro was demonstrated.19911785940
induction of 2'-5' a synthetase activity and interferon in humans by bacteria used in dairy products.the production of interferon by fasted human subjects in response to lactic bacteria lactobacillus bulgaricus and streptococcus thermophilus was evaluated in vivo and in vitro. the 2'-5' a synthetase activity of blood mononuclear cells was used to estimate interferon production following a single ingestion of 10(11) bacteria in yoghurt or sterile milk (controls). the level of the 2'-5' a synthetase of the yoghurt fed subjects was 83% (p = 0.002) higher than that of the milk fed controls 24 hours ...19911813017
isolation and characterization of chromosomal promoters of streptococcus salivarius subsp. thermophilus.a promoter probe vector, ptg244, was constructed with the aim of isolating transcription initiation signals from streptococcus thermophilus (streptococcus salivarius subsp. thermophilus). ptg244 is based on the escherichia coli-streptococcus shuttle vector ptg222, into which the promoterless chloramphenicol acetyltransferase gene of bacillus pumilus (cat-86) was cloned. random sau3a fragments from the s. thermophilus a054 chromosomal dna were cloned upstream of the cat-86 gene by using e. coli a ...19911854195
analysis of the lacz sequences from two streptococcus thermophilus strains: comparison with the escherichia coli and lactobacillus bulgaricus beta-galactosidase sequences.the lacz gene from streptococcus thermophilus a054, a commercial yogurt strain, was cloned on a 7.2 kb psti fragment in escherichia coli and compared with the previously cloned lacz gene from s. thermophilus atcc 19258. using the dideoxy chain termination method, the dna sequences of both lacz structural genes were determined and found to be 3071 bp in length. when the two sequences were more closely analysed, 21 nucleotide differences were detected, of which only nine resulted in amino acid cha ...19911901904
influence of nonfermented dairy products containing bacterial starter cultures on lactose maldigestion in humans.the effect of nonfermented dairy products containing yogurt or acidophilus cultures on lactose utilization by lactose-maldigesting humans was investigated. yogurt and acidophilus milk containing 10(7) or 10(8) of streptococcus thermophilus and lactobacillus bulgaricus, or lactobacillus acidophilus, respectively, were prepared using commercially processed 2% low fat milk. immediately following inoculation, products were refrigerated. lactose maldigestion was monitored by measuring breath hydrogen ...19911903136
[cloning the gene of beta-galactosidase from the industrial strain of streptococcus lactis 111 in e. coli cells and conjugated transfer of this gene to streptococcus thermophilus cells].the ability of the industrial strains of streptococcus lactis to synthesize the enzyme beta-galactosidase was studied. five strains among sixteen were found to produce high levels of the enzyme. the beta-galactosidase gene in the most active strain streptococcus lactis 111 was shown to be located on the 50 kb conjugative plasmid. the plasmid was transferred by conjugation into streptococcus thermophilus cells and subsequently the gene for beta-galactosidase was studied in transconjugants. the be ...19911906985
distribution and purification of aspartate racemase in lactic acid bacteria.the distribution of aspartate racemase (ec 5.1.1.13) in various kinds of bacteria demonstrated that the enzyme occurs in lactic acid bacteria, such as streptococcus species and lactobacillus species. the enzyme from streptococcus thermophilus iam10064 was more thermostable than that from streptococcus lactis iam1198 which contained the enzyme most abundantly among the lactic acid bacteria we examined here. we purified the enzyme about 3400-fold to homogeneity from cell-free extract of s. thermop ...19911907199
inhibition of clostridium tyrobutyricum by bacteriocin-like substances produced by lactic acid bacteria.lactic acid bacteria were selected for their inhibitory activity against clostridium tyrobutyricum under conditions that eliminate the effects of lactic acid and hydrogen peroxide. four strains were isolated belonging to the species lactococcus lactis ssp. lactis. the sensitivity of the inhibitory substances to pronase and trypsine indicates that they are proteins or peptides different from nisin. their resistance to phospholipase d indicates that they are also different from lactostrepcin. the ...19911907300
strains and species of lactic acid bacteria in fermented milks (yogurts): effect on in vivo lactose digestion.lactose in yogurt with live bacteria is better tolerated than lactose in other dairy foods, partly because of the activity of microbial beta-galactosidase (beta-gal), which digests lactose in vivo. to evaluate the ability of different strains and species of lactic acid bacteria to digest lactose in vivo, yogurts (containing mixtures of strains of streptococcus salivarius subsp thermophilus and lactobacillus delbrueckii subsp bulgaricus) and fermented milks (containing individual species of s the ...19911957819
antitumor activity of streptococcus thermophilus against fibrosarcoma: role of t-cells.antitumor activity induced by a heat-killed preparation of s. thermophilus against mouse fibrosarcoma was investigated. the treatment of swiss mice with s. thermophilus prior to transplantation could not prevent tumors. however, animals cured by treatment with a s. thermophilus preparation failed to take up the tumor when rechallenged with fibrosarcoma. s. thermophilus did not induce antitumor activity in animals immunosuppressed by sublethal whole body gamma-irradiation (4 gy) or hydrocortisone ...19912004352
transfer and expression of a streptomyces cholesterol oxidase gene in streptococcus thermophilus.the recombinant plasmid pnco937 (8.1 kbp) containing a streptomyces sp. cholesterol oxidase gene was introduced into streptococcus thermophilus by electrotransformation. transformation frequency was 7.2 x 10(5) colony forming units/micrograms of dna. the presence of the cholesterol oxidase gene in s. thermophilus was confirmed with southern blot analysis using a biotinylated probe. thin-layer chromatographic analysis showed the expression of the streptomyces cholesterol oxidase gene resulting in ...19912043280
molecular cloning and nucleotide sequencing of the aspartate racemase gene from lactic acid bacteria streptococcus thermophilus.the gene coding aspartate racemase (ec 5.1.1.13) was cloned from the lactic acid bacteria streptococcus thermophilus iam10064 and expressed efficiently in escherichia coli. the 2.1 kilobase pairs long full length clone had an open reading frame of 729 nucleotides coding for 243 amino acids. the calculated molecular weight of 27,945 agreed well with the apparent molecular weight of 28,000 found in sodium dodecyl sulfate (sds) polyacrylamide gel electrophoresis of the aspartate racemase purified f ...19912054383
galactose utilization in lactobacillus helveticus: isolation and characterization of the galactokinase (galk) and galactose-1-phosphate uridyl transferase (galt) genes.by complementing appropriate gal lesions in escherichia coli k802, we were able to isolate the galactokinase (galk) and galactose-1-phosphate uridyl transferase (galt) genes of lactobacillus helveticus. tn10 transposon mutagenesis, together with in vivo complementation analysis and in vitro enzyme activity measurements, allowed us to map these two genes. the dna sequences of the genes and the flanking regions were determined. these revealed that the two genes are organized in the order galk-galt ...19912066342
characterization and comparison of virulent bacteriophages of streptococcus thermophilus isolated from yogurt.seven virulent bacteriophages of streptococcus thermophilus were characterized at the molecular level and classified into 2 subgroups (a and b) by dna/dna hybridization experiments and analysis of their structural proteins. two representatives of subgroups a and b were compared to 3 representatives of neve's subgroups i, ii and iii (neve et al, 1989) by southern blot experiments. these isometric-headed phages possess a double-stranded dna genome varying between 30-44 kilobase (kb) pairs. subgrou ...19902095920
antimutagenic activity of milk fermented by streptococcus thermophilus and lactobacillus bulgaricus.antimutagenic activity of acetone or ethylacetate extracts of skim milk fermented by streptococcus thermophilus, lactobacillus bulgaricus, or a combination of both the organisms was studied using salmonella typhimurium (ta 98 and ta 100). mutagens used were 4-nitroquinoline-n-oxide (a direct-acting mutagen) and 2-aminofluorene (a mutagen requiring s9 activation). extracts from all fermented milks showed significant (p less than .05) dose response in suppressing the number of revertants caused by ...19902099363
[cloning of the streptococcus thermophilus beta-galactosidase gene and its expression in escherichia coli and bacillus subtilis cells].the beta-galactosidase gene from the chromosome of streptococcus thermophilus, strain 6 kb, has been cloned on a vector plasmid pbr322. the corresponding gene has been found to be located on the pst1 dna fragment. the restriction map of this 6 kb fragment has been constructed. the shortening of the dna fragment carrying the beta-galactosidase gene has been achieved by digestion of the recombinant derivative of pbr322 by the restriction endonuclease sau3a under the conditions of incomplete hydrol ...19902114530
structure of an exocellular polysaccharide produced by streptococcus thermophilus.streptococcus thermophilus strains grown on skimmed milk produced a viscosifying, exocellular, and water-soluble polysaccharide which contains d-glucose, d-galactose, and n-acetyl-d-galactosamine in the ratio of 1:2:1. methylation analysis identified the glycosidic linkages in the tetrasaccharidic repeating-unit, and smith degradation and nitrous deamination after n-deacetylation gave the sequence of monosaccharides in the repeating-unit. the anomeric configurations of the sugar residues were de ...19902165858
freeze-drying of streptococcus thermophilus: a comparison between the vacuum and the atmospheric method.frozen suspensions of streptococcus thermophilus were freeze-dried in a vacuum or a fluidized adsorbent bed at atmospheric pressure. optimum operating conditions for each process were defined. for the duration of processing and survival rate of bacteria, in each case vacuum freeze-drying seemed more satisfactory than atmospheric pressure freeze-drying. the use of reconstituted skimmed milk as a suspension medium provides good protection for s. thermophilus.19902249458
molecular genetics of streptococcus thermophilus.the metabolism and genetics of streptococcus thermophilus (presently streptococcus salivarius ssp. thermophilus) have only been investigated recently despite its widespread use in milk fermentation processes. the development of recombinant dna technology has allowed impressive progress to be made in the knowledge of thermophilic dairy streptococci. in particular, it has permitted a careful analysis of phenotypically altered variants which were derived from a mother strain by plasmid or chromosom ...19902271225
isolation and characterization of a type ii restriction endonuclease from streptococcus thermophilus.a type ii restriction endonuclease sth134i was isolated from streptococcus thermophilus strain 134. the enzyme is an isoschizomer of hpaii. the restriction endonuclease is most active at mg(ii) greater than or equal to 5 mm; in the ph range of 7.5-8; temperature of 50 degrees-55 degrees c; and (kcl) or (nacl) below 100 mm. double digestion and ligation experiments showed that sth134i apparently recognized and cleaves dna at the sequence c1cgg to produce two-base, 5'-protruding ends.19902323549
purification and thermostability of beta-galactosidase (lactase) from an autolytic strain of streptococcus salivarius subsp. thermophilus.beta-galactosidase from an autolytic strain of streptococcus salivarius subsp. thermophilus was purified 109-fold to near homogeneity. the yield of purified enzyme was 41% and the specific activity was 592 o-nitrophenyl beta-d-galactopyranoside u/mg at 37 degrees c. two isozymes were present, but only one subunit was detected, having a mol. wt of 116,000. enzyme stability was 37-83 times greater in milk than in buffer in the range 60-65 degrees c. at 60 degrees c the half-life in milk was 146 mi ...19892495313
a method for determining beta-galactosidase activity of yogurt cultures in skim milk.a method was developed for determining the specific activity of bacterial beta-galactosidase (ec 3.2.1.23) during growth of streptococcus thermophilus and lactobacillus bulgaricus in skim milk. individual and mixed strain cultures of s. thermophilus (st 3642, st14485) and l. bulgaricus (lb11842, lb880) were examined for growth (od at 600 nm and viable cell counts), acid production, and beta-galactosidase activity (expressed as a function of recoverable tca-precipitable cellular protein). culture ...19892495315
effect of threonine and glycine concentrations on threonine aldolase activity of yogurt microorganisms during growth in a modified milk prepared by ultrafiltration.to evaluate the combined effects of threonine and glycine concentrations during growth on threonine aldolase activity (ec 2.1.2.1) of yogurt microorganisms, streptococcus thermophilus and lactobacillus bulgaricus, a modified milk growth medium was prepared using uf to deplete the free amino acid level. threonine and glycine were added according to a 2x2x2 factorial design at 5 or 195 microg.ml(-1) along with a standard amino acid mixture. acetaldehyde production and threonine aldolase activity w ...19892501366
serological identification of streptococcus salivarius subsp. thermophilus.streptococcus salivarius subsp. thermophilus (str. thermophilus) has no group-specific antigen. hcl extracts of 551 strains of streptococci isolated from cheese or yogurt (123 str. thermophilus and 428 enterococcus faecalis - ent. faecium spp.) were examined with three type-specific antisera prepared against representatives of str. thermophilus and also with lancefield group d antisera. all typical (80) or atypical (43) strains of str. thermophilus reacted with at least one type-specific antiser ...19892512335
purification and substrate specificity of a strongly hydrophobic extracellular metalloendopeptidase ("gelatinase") from streptococcus faecalis (strain 0g1-10).an extracellular zn-endopeptidase was purified to homogeneity from the culture filtrates of streptococcus faecalis (human oral strain 0g1-10) by a procedure that comprised concentration in an amicon hollow fiber system, ammonium sulfate precipitation, gel permeation chromatography, hydrophobic interaction chromatography (batch operation on phenyl-sepharose cl-4b), followed by fast protein liquid chromatography (fplc) on a phenyl-superose hr 5/5 column, and finally fplc on a superose 12 hr 10/30 ...19892536744
uptake of glutamic acid by streptococcus salivarius subsp. thermophilus cnrz 302.glutamic acid uptake in streptococcus salivarius subsp. thermophilus was energy dependent, the source of energy and adaptation to sugar being important to efficiency of uptake. the disaccharides, lactose and sucrose, stimulated uptake, but cells grown in glucose were more active. optimum temperature was approximately 40 degrees c and ph approximately 7.0. nacl was strongly inhibitory to the uptake of glutamic acid although not to that of isoleucine. high specificity existed because only l-aspart ...19892564854
growth kinetics of streptococcus thermophilus at subbacteriostatic penicillin g concentrations.streptococcus thermophilus may be subjected to the effects of penicillin g in contaminated milk used for yogurt production. sensitivity of this microorganism to penicillin g has been conventionally determined by the help of penicillin g-impregnated disks placed on solid media. it was observed that the bacteriostatic penicillin g concentration was much greater in liquid media than in solid media. the conventional disk method may not be appropriate for antibiotic sensitivity determinations if the ...19892600217
lactose transport system of streptococcus thermophilus: a hybrid protein with homology to the melibiose carrier and enzyme iii of phosphoenolpyruvate-dependent phosphotransferase systems.the gene responsible for the transport of lactose into streptococcus thermophilus (lacs) was cloned in escherichia coli as a 4.2-kilobase fragment from an ecori library of chromosomal dna by using the vector pkk223-3. from deletion analysis, the gene for lactose transport mapped to two hindiii fragments with a total size of 2.8 kilobases. the gene was transcribed in e. coli from its own promoter. functional expression of lactose transport activity was shown by assaying for the uptake and exchang ...19892644191
genome comparison of lactococcus strains by pulsed-field gel electrophoresis.the two restriction enzymes smai and apai were found to produce distributions of dna fragments useful for genome analysis of some lactic acid bacteria (lactococcus lactis and streptococcus salivarius subsp. thermophilus) by pulsed-field gel electrophoresis. the genome size was estimated to be 1750 to 2500 kb depending on the species. each strain displayed unique restriction patterns; nevertheless, the percentage of the comigrating fragments of two isogenic or closely related strains was about 80 ...19892737464
purification and characterization of x-prolyl-dipeptidyl-aminopeptidase from lactobacillus lactis and from streptococcus thermophilus.x-prolyl-dipeptidyl-aminopeptidase recently was found in several lactic acid bacteria. this article describes the purification of the enzymes from lactobacillus lactis and streptococcus thermophilus and compares their characteristics. enzymes from both strains are serine-peptidases. they both have a molecular weight of about 165,000 daltons, an isoelectric point near 4.5, and are constituted of two subunits. the ph optimum of the enzyme isolated from l. lactis is 7.0, whereas the enzyme from s. ...19872884242
isolation and partial characterization of plasmid dna from streptococcus thermophilus.of 23 strains of streptococcus thermophilus examined, 5 were found to contain a single small cryptic plasmid, designated phm1 through phm5. through analysis by restriction endonuclease mapping and dna-dna hybridization, the five plasmids were found to be closely related. they were present in 4 to 18 copies per cell and ranged in size from 1.4 to 2.2 megadaltons. plasmids phm1 and phm5, as well as phm2 and phm4, were found to be identical. single restriction endonuclease sites were observed on ea ...19853002269
cloning and expression of the beta-d-galactosidase gene from streptococcus thermophilus in escherichia coli.the beta-d-galactosidase (beta-gal) gene from streptococcus thermophilus was cloned to isolate and characterize it for potential use as a selection marker in a food-grade cloning vector. chromosomal dna from s. thermophilus 19258 was cleaved with the restriction enzyme psti and ligated to pbr322 for transformation into escherichia coli jm108. a beta-galactosidase-positive clone was detected by its blue color on a medium supplemented with 5-bromo-4-chloro-3-indolyl-beta-d-galactoside. this transf ...19863015026
enhancement of host resistance against salmonella typhimurium infection by a diet supplemented with yogurt.the effect of a diet supplemented with yogurt containing live lactobacilli (lab) - lactobacillus bulgaricus and streptococcus thermophilus - on the response of inbred mice to infection with salmonella typhimurium was elaborated. the results of our experiments were consistent with the hypothesis that modifications of the microflora influence the adherence of s. typhimurium to intestinal mucosa, the natural antibacterial activity of the peyer's patches lymphocytes, the accumulation of the macropha ...19883058777
antimutagenic properties of lactic acid-cultured milk on chemical and fecal mutagens.the antimutagenic properties of milk cultured with lactobacillus bulgaricus and streptococcus thermophilus were examined using streptomycin-dependent strains of salmonella in an in vitro assay system. the mutagens utilized for testing included 2-(2-furyl)-3-(5-nitro-2-furyl) acrylamide, 4-nitroquinoline-n-oxide, and fecal mutagenic extracts from cats, monkeys, dogs, and other mammals. both types of cultured milk exhibited antimutagenic activity on all mutagens used. antimutagenic activities of t ...19863097092
influence of mastitis on growth of starter organisms used for the manufacture of fermented milks.the effect of milk containing increased somatic cells on the starter organisms streptococcus thermophilus, lactobacillus bulgaricus and l. acidophilus was examined. increased somatic cell count resulted in stimulation of str. thermophilus owing to increased proteolysis, but inhibition of l. acidophilus as a consequence of increased phagocytic activity of the polymorphonuclear leucocytes19863098812
a comparison of beta-galactosidase specific activities in strains of streptococcus thermophilus.six streptococcus thermophilus strains were examined for growth, acid production, and beta-galactosidase activity per milligram protein (specific activity), so that strain comparisons could be made. a wide range in activity was observed. activity depended on growth time in m17 broth and, for most strains, continued to increase after cells had reached stationary phase. maximum activity was at 16 h and ranged from 0 to 58 units/mg protein. strain st exhibited no beta-galactosidase activity but had ...19863100589
survival of lactic acid bacteria in the human stomach and adhesion to intestinal cells.the survival of four strains of lactic acid bacteria in human gastric juice, in vivo and in vitro, and in buffered saline, ph 1 to 5, has been investigated. the strains studied include two lactobacillus acidophilus strains, lactobacillus bulgaricus, and streptococcus thermophilus. in addition, the adhesion of these strains to freshly collected human and pig small intestinal cells and to pig large intestinal cells has been studied and the effect of milk on both survival and adhesion tested. as a ...19873106442
enhancement of immune response in mice fed with streptococcus thermophilus and lactobacillus acidophilus.swiss mice, fed for 8 consecutive d with 50 micrograms/d of viable cultures of lactobacillus acidophilus and streptococcus thermophilus, showed significant variation in their immune system. in order to study this phenomenon assays for macrophage and lymphocyte function were carried out. both lactic acid bacteria enhanced significantly the enzymatic and phagocytic activity of peritoneal macrophages as checked against the controls and also accelerated the phagocytic function of the reticuloendothe ...19873110233
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 ...19873122654
development of an efficient spheroplast transformation procedure for s. thermophilus: the use of transfection to define a regeneration medium.the conditions for the efficient polyethylene glycol (peg)-induced spheroplast transformation of three strains of streptococcus thermophilus have been established. this required the careful optimization of various experimental parameters, the most important being the choice of the lytic enzyme (lysozyme versus mutanolysin), the extent of cell wall digestion and the conditions for the peg shock which were found to be strain-specific. the transfection assay we had previously developed for s. therm ...19883139074
genetic transformation of streptococcus thermophilus by electroporation.a rapid and convenient electroporation procedure was developed for the genetic transformation of intact cells of streptococcus thermophilus with various species of plasmid dna. transformation frequency was influenced by the capacitance and voltage selected for electric pulsing, the ph and composition of the electroporation medium and the molecular mass of the transforming dna. electroporation is a simple and effective technique to introduce plasmid dna into s. thermophilus and useful in the deve ...19883139075
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 ...19883141041
adherence of specific yogurt micro-organisms to human peripheral blood lymphocytes.yogurt lactic-acid-bacteria (lab) consisting of lactobacillus bulgaricus and streptococcus thermophilus were evaluated for their capacity to bind to human peripheral blood lymphocytes (pbl). these micro-organisms adhere to human t lymphocytes, and bind to b lymphocytes, in high and low frequencies, respectively. in addition, a quantitative analysis of lab binding to pbl was carried out using the same parameters previously applied to a salmonella model. the effect of yogurt lab on the natural ant ...19883144641
[adjuvant activity of lactic bacteria: perspectives for its use in oral vaccines].the effect of the oral and subcutaneous administration of lactobacillus casei, lactobacillus acidophilus, lactobacillus bulgaricus and streptococcus thermophilus on humoral antibody production and delayed type hypersensitivity response against sheep red blood cells (srbc) was studied. the species of the genus lactobacillus proved to be more effective in both cases, effects being stronger when working with viable bacteria than with non-viable cells. the stimulation of primary cellular and humoral ...19883231712
plasmid transduction in streptococcus thermophilus.streptococcus thermophilus is a common dairy starter for which very few genetic exchange systems have been described. here we report plasmid transduction by phi 17 alpha and phi 56 alpha, two virulent phages of industrial yogurt starter strains. several replicons could be transduced, independently of their size, with efficiencies which are high enough to allow gene transfer from a transformable intermediary strain of s. thermophilus to other hosts of the bacteriophages studied.19883405204
oxygen uptake activity and aerobic metabolism of streptococcus thermophilus sth450.streptococcus thermophilus sth450 had a very high oxygen uptake. this strain was then compared with aerobic metabolism to s. thermophilus atcc 19258, a reference strain for aerobic metabolism. molecular oxygen, which was absorbed by s. thermophilus sth450 during aerobic glycolytic metabolism, was involved in the oxidation of nadh by the catalytic activity of nadh oxidase. the portion of pyruvate that corresponded to the oxidized nadh was committed to form alpha-acetolactate, acetoin, and diacety ...19873584599
influence of temperature on associative growth of streptococcus thermophilus and lactobacillus bulgaricus.compatibility of streptococcus thermophilus and lactobacillus bulgaricus during associative growth as dependent on optimum growth temperature was determined. optimum growth temperatures for 9 strains of s. thermophilus and 10 strains of l. bulgaricus ranged from 35 to 42 degrees c for s. thermophilus and 43 to 46 degrees c for l. bulgaricus. streptococcus thermophilus and l. bulgaricus strains exhibiting similar to divergent optimum growth temperatures were combined (1:1 vol/vol) and incubated i ...19863805441
improved media for differentiation of rods and cocci in yogurt.selected yogurt starters and commercial samples grew on elliker's lactic agar supplemented with .1% tween 80 and 50 micrograms/ml of 2,3,5-triphenyltetrazolium chloride to produce small, red streptococcus thermophilus colonies and larger, white lactobacillus bulgaricus colonies. the distinction was somewhat strain dependent but was satisfactory in most cases. addition of 7% skim milk (11% solids) to lactic agar in place of 2,3,5-triphenyltetrazolium chloride allowed good rod-coccus differentiati ...19863805442
use of microbial beta-lactamase to destroy penicillin added to milk.a simple method is described for destruction of penicillin residues in bulk milk to an undetectable amount (less than .003 u/ml) with commercially available crude beta-lactamase enzyme. milk containing .1 or .5 u/ml penicillin g was treated with .01 to 1.0 mu/ml of beta-lactamase (bacillus cereus) for up to 96 h. the bacillus stearothermophilus var. calidolactis assay was used to quantify penicillin in milk between .003 to 1.0 u/ml. the .5 u/ml of penicillin g was reduced to an undetectable amou ...19853930584
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 ...19853933276
nutritional value of yogurt.yogurt, made from fortified skim milk by conventional methods using streptococcus thermophilus and lactobacillus bulgaricus, was used in studies of the effect of fermentation on nutritional value of milk. in all experiments, the product was compared with the uninoculated base milk. the concentration of most vitamins was less in yogurt than in milk and was most noticeably so for biotin which was 60% less. the effect on folic acid content was inconsistent. in nutritional experiments with rats, hig ...19853989067
galactose transport in streptococcus thermophilus.although streptococcus thermophilus accumulated [14c]lactose in the absence of an endogenous energy source, galactose-fermenting (gal+) cells were unable to accumulate [14c]galactose unless an additional energy source was added to the test system. both gal+ and galactose-nonfermenting (gal-) strains transported galactose when preincubated with sucrose. accumulation was inhibited 50 or 95% when 10 mm sodium fluoride or 1.0 mm iodoacetic acid, respectively, was added to sucrose-treated cells, indi ...19854083879
galactokinase activity in streptococcus thermophilus.atp-dependent phosphorylation of [14c]galactose by 11 strains of streptococcus thermophilus indicated that these organisms possessed the leloir enzyme, galactokinase (galk). activities were 10 times higher in fully induced, galactose-fermenting (gal+) strains than in galactose-nonfermenting (gal-) strains. lactose-grown, gal- cells released free galactose into the medium and were unable to utilize residual galactose or to induce galk above basal levels. gal+ s. thermophilus 19258 also released g ...19854083880
[lipolytic activity of streptococcus thermophilus and of lactobacillus bulgaricus]. 19744422872
[general properties and specificity of action of a neutral intracellular endopeptidase from streptococcus thermophilus]. 19744451671
susceptibility of cheese and yoghurt starter bacteria to antibiotics.eight single-strain lactic streptococci, three commercial cheese starters, and six lactic acid bacteria isolated from yoghurt were examined for their susceptibility to penicillin, cloxacillin, tetracycline-hydrochloride and streptomycin. the ranges of the antibiotics causing 50% inhibition of the bacteria were (mug/ml): penicillin, 0.009 to 0.20; cloxacillin, 0.24 to 2.50; tetracycline, 0.09 to 0.60; and streptomycin, 0.35 to 13.0. the average concentrations required to cause 50 and 100% inhibit ...19724624215
[isolation and amino acid composition of casein peptides stimulating growth if streptococcus thermophilus]. 19724677725
[inventory of different intracellular peptidase activities in streptococcus thermophilus. purification and properties of a dipeptide hydrolase and an aminopeptidase]. 19734749719
[effect of glucagon peptide fragments in relation to growth of streptococcus thermophilus]. 19734771753
formation of amino acid-rna ligases during growth phases of streptococcus thermophilus. 19684882415
[demonstration of streptococcus thermophilus bacteriophage, cause of yoghurt fermentation accident]. 19704985226
[contents of antibiotics and other growth-inhibiting substances in milk. results of a countrywide survey. ii. study of the degree of contamination of polish milk with substances inhibiting the growth of streptococcus thermophilus]. 19715171829
[bacteriophages and phage-sensitive and -resistant strains of streptococcus thermophilus]. 19705444287
[differentation of phage-sensitive and phage-resistant strains of streptococcus thermophilus]. 19705537328
[characterization of a bacteriophage of streptococcus thermophilus]. 19705537582
counting and sizing of the individual cells of chain-forming streptococcus thermophilus with an electric particle counter. 19715559613
stimulation of streptococcus thermophilus growth in mastitic milk.growth of streptococcus thermophilus was faster in mastitic milk, aseptically collected following intramammary infusion of escherichia coli endotoxin, than in normal aseptically collected milk. the contribution of polymorphonuclear leucocytes (pmn), of plasma and plasmin to this stimulation has been investigated. addition of plasmin to low cell count milk stimulated growth of the streptococcus to the same degree as mastitic milk. however, addition of plasma or pmn from blood or from milk were le ...19846231318
effect of prostaglandin e1-induced elevation of cyclic amp on glucose repression in the lactic streptococci.cyclic adenosine 3', 5' -monophosphate (camp) activity was observed in streptococcus lactis c2, streptococcus cremoris c10, streptococcus diacetlactis 18-16, and streptococcus thermophilus c3. in vitro assays of cell-free extracts obtaianed from s. lactis c2 showed that the camp-associated enzymes adenyl cyclase and phosphodiesterase were also present. in vitro experiments showed that prostaglandin e1 (pge) stimulation of adenyl cyclase increased camp concentrations approximately fivefold, and i ...19806250686
the effect of yoghurt on some components of the gut microflora and on the metabolism of lactose in the rat.feeding yoghurt or base milk (from which the yoghurt was prepared by fermentation) to rats increased the counts of coliforms in the gut whereas the counts of lactobacilli were reduced by yoghurt but not by the base milk. lactobacillus bulgaricus survived in the guts of gnotobiotic and conventional rats when yoghurt was fed continuously. streptococcus thermophilus also survived in gnotobiotic rats but its ability to survive in conventional rats could not be examined. both organisms failed to colo ...19846427170
[in vivo study of the growth characteristics of the microflora of armenian yogurt].the microflora from the armenian yoghurt was studied during its growth on the optimal for the medium (skim milk) using objectives of the peshkoff system. it was shown that certain organisms of lactobacterium jogorti tended to branch at the early stages of their growth, and the cells elongated and formed complex coils and helices by the third-fourth day of growth. compact aggregates of cocci having angular outlines appeared in the culture of streptococcus thermophilus by the end of the second day ...19806446658
phosphofructokinases from lactobacteriaceae. ii. purification and properties of phosphofructokinase from streptococcus thermophilus.phosphofructokinase (atp : d-fructose-6-phosphate 1-phosphotransferase, ec 2.7.1.11) from streptococcus thermophilus has been purified. it is a tetramer composed of identical subunits of molecular weight 36 000 and exhibits michaelis-menten kinetics. compared to the phosphofructokinases from taxonomically related bacteria, the enzyme from s. thermophilus is more stable at high temperatures. in addition, it has been demonstrated that the phosphofructokinases from lactobacteria and also from baci ...19816457643
effect of feeding fermented milk on the incidence of chemically induced colon tumors in rats.the effect of feeding skim milk fermented by streptococcus thermophilus or lactobacillus bulgaricus on the incidence of chemically induced colon tumors was studied in rats. weanling fisher-344 rats were fed chow plus skim milk (sm), chow plus sm fermented by s. thermophilus, chow plus sm fermented by l. bulgaricus, or chow plus water until sacrifice at 36 weeks, or before if moribund. colon tumors were induced by s.c. injections of 1,2-dimethylhydrazine hydrochloride during weeks 3 through 22. t ...19836669478
dna base composition, dna-dna homology and long-chain fatty acid studies on streptococcus thermophilus and streptococcus salivarius.dna base composition, dna-dna homology and long-chain fatty acid studies were performed on streptococcus thermophilus and streptococcus salivarius. these species possess similar mol % g + c values (about 37 to 41), long-chain fatty acid profiles and belong to a single dna homology group. on the basis of the present and earlier studies it is proposed that streptococcus thermophilus (orla-jensen) be reclassified as streptococcus salivarius subsp. thermophilus comb. nov.19846726177
contribution of streptococcus thermophilus to growth-stimulating effect of yogurt on rats.the origin of the growth-stimulating factor in yogurt was studied in rats fed liquid or freeze-dried diets of milk, yogurt, milks fermented individually by streptococcus thermophilus and lactobacillus bulgaricus, milks to which cells of streptococcus thermophilus and lactobacillus bulgaricus were added. diets containing sonicated cells, cell supernatant, and cell fractions also were fed. milk fermented by streptococcus thermophilus and milk plus streptococcus thermophilus cells stimulated growth ...19836841747
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