PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Lactobacillus acidophilus”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1976

Incorporation of deoxycytidine into deoxyribonucleic acid deoxycytidylate in Lactobacillus acidophilus R-26.

Lactobacillus acidophilus R-26 a strain deficient in ribonucleotide reductase, was grown with [G-14C]deoxycytidine as the only source of deoxyribose in the medium. Of the radioactivity incorporated into deoxyribonucleic acid, a fifth moved directly into deoxyribonucleic acid deoxycytidylate, without deamination. Furthermore, deoxycytidine and thymidine nucleotides had similar sugar/base ratios, suggesting a direct conversion of deoxycytidine nucleotides to thymidine nucleotides through deamination, without further dilution by glycosyl transfer. Although radioactivity was incorporated into both the sugar and base moieties of deoxyribonucleic acid pyrimidine deoxyribonucleotides, only the sugar moiety of purine deoxyribonucleotides was labeled. Purine deoxyribonucleotides probably were synthesized by glycosyl transfer from [G-14C]deoxycytidine to unlabeled purines, followed by phosphorylation of the deoxynucleotides.

Cytosine Nucleotides↗
PubMed1977

Specific antigens of Lactobacillus acidophilus.

Antigens specific for Lactobacillus acidophilus were investigated by double immunodiffusion in agar-gel. Antigenic materials were extracted from whole bacteria and some walls with cold trichloroacetic acid. Antisera were prepared by intravenous injection into rabbits of suspensions of whole organisms in solutions of bovine serum albumin, which had been heated and then washed. Four specific antigens were found as precipitinogens and denoted as antigens 11, 12, 13 and 14. Of 43 strains of L. acidophilus studied, 33 strains possessed antigen 11, six strains antigen 12, two strains antigen 13 and two strains antigen 14. Sugar compositions of wall preparations were analysed in an attempt to characterize the determinants of antigens 11 and 12. The walls contained glucose, galactose, hexosamine and sometimes glycerol, but no rhamnose was found. It was considered that alpha-glucopyranose was the major component of the determinant of antigen 11 since trehalose and maltose significantly inhibited the reaction between antibody 11 and its antigen; the determinant of antigen 12 was not clarified.

Antigen-Antibody Reactions↗
PubMed1976

Control of and synthesis in Lactobacillus acidophilus Role of RNA and free amino acids.

In Lactobacillus acidophilus, the DNA synthesis in cells incubated in the absence of essential amino acids reaches levels corresponding to the initiation of further replication cycles than just to completing the cycles already running. This "relaxation of DNA synthesis" is stimulated by the presence of inhibitors of protein synthesis and by the presence of deoxyadenylate. These enhancements of DNA replication are cancelled by actinomycin D. In the presence of inhibitors of protein synthesis, the relaxtion of DNA synthesis is further stimulated by free amino acids. The effect of free amino acids, unlike in the former cases, is not inhibited by actinomycin D. It proposed that the chromosome replication in Lactobacillus acidophilus is regulated similarly as in some plasmids, i.e. independently of the synthesis of protein, depending on the synthesis of RNA and, in addition, on the presence of free amino acids.

Amino Acids↗
PubMed1978

Comparison of tRNA nucleotidyltransferase from Escherichia coli and Lactobacillus acidophilus.

Purification of tRNa nucleotidyltransferase from Lactobacillus acidophilus ATCC 4963 and Escherichia coli MRE 600 by preparative polyacrylamide gel electrophoresis is described. Both enzymes gave a single band on analytical polyacrylamide-gel electroesis and sodium dodecylsulfate gels. Chromatography of the high speed supernatant from Lactobacillus at low salt concentrations gave three enzyme fractions of molecular weights about 45 000, 90 000, and 120 000. At 1M NaCl only the first enzyme fraction was found. Kinetic data for both enzymes are given.

Adenosine Triphosphate↗
PubMed1975

N-6-(delta-2-isopentenyl) adenosine: hydrolysis by a mucleosidase isolated from Lactobacillus acidophilus cells.

A nucleosidase activity has been isolated from Lactobacillus acidophilus which rapidly hydrolyses N-6 (delta-2-isopentenyl) adenosine to its corresponding base, N-6(delta-2-isopentenyl) adenine. The activity can be distinguished from the spleen exzyme (EC. 2.4.2.1), a purine nucleoside transferase, on the basis of its substrate specificity, electrophoretic behavior, and nondependence on phosphate. The bacterial enzyme hydrolyzes both inosine and isopentenyl adenosine, giving Km values of 63.3muM and 177 muM respectively. The presence of this enzyme in bacteria counts for the rapid conversion of the parent nucleoside to isopentenyl adenine, which has been observed in these cells. The enzyme thus assumes importance as one of the catabolic activities available to the cell for metabolizing the cytokinin, N-6-(delta-2-isopentenyl) adenosine.

Adenosine↗
PubMed1975

Transmission of Lactobacillus jensenii and Lactobacillus acidophilus from mother to child at time of delivery.

The presence of Lactobacillus jensenii and Lactobacillus acidophilus has been studied in specimens from the rectum and vagina of the mother, from the mouth of the infant at the time of delivery, and from the mouth and rectum of infants six days of age. L. jensenii could be differentiated from other species of lactobacilli by the following combination of characteristics: production of only D-lactate, hydrolysis of arginine, and fermentation of cellobiose, galactose, and ribose, but not of lactose. L. jensenii and L. acidophilus were common inhabitants of the vagina. In spite of a contamination of the infant's mouth by L. jensenii and L. acidophilus during delivery, neither of these organisms became established in the mouth of the newborn infants.

Adult↗
PubMed1975

Turnover of the cell wall peptidoglycan of Lactobacillus acidophilus. The presence of a fraction immune to turnover.

Exponentially growing cultures of Lactobacillus acidophilus strain 60AM Gasser were previously shown to lose about one-third of their cell wall peptidoglycan per generation via turnover (Boothby, D., Daneo-Moore, L., Higgins, M. L., Coyette, J., and Shockman, G. D. (1973) J. Biol. Chem. 248, 2161-2169). We now show that 20 to 30% of the [3H]lysine initially present in insoluble peptidoglycan fractions was retained after 4 or more generations of continued exponential growth of cultures in the absence of label. Treatment of peptidoglycan fractions, before and after 6 or 8 generations of chase with lysozyme (EC 3.2.1.17), released soluble products containing [3H]lysine which had electrophoretic mobilities identical with the disaccharide-peptide derivatives obtained from the wall peptidoglycan of this species. Because protein is known to contaminate peptidoglycan residues, the double labeled technique was used to show that one-half or less of the label lysine present after 6 or 8 generations of chase could be attributed to protein contamination. This then left a minimum fraction of 10 to 20% of the peptidoglycan that was immune to turnover. The absence of turnover of peptidoglycan labeled during short pulses has now been quantitated to show that pulses shorter than 12% of a generation (6 to 7 min) did not turn over. This turnover-immune fraction is in reasonably good agreement with the immune fraction of 10 to 20% observed after long periods of chase of extensively labeled peptidoglycan.

Amino Acids↗
PubMed1976

Death of Lactobacillus acidophilus caused by incorporated 3H-thymine during incubation without amino acids.

Of the cells of Lactobacillus acidophilus R-26 incorporated 3H-thymine (specific radioactivity 1.57 Ci/mmol or 3.15 Ci/mmol), their transfer to a medium without essential amino acids resulted in their death. This death may be interpreted in such a way that cell damage caused by disintegration of tritium cannot be effectively repaired under conditions of amino acid deprivation. The experimental eonditions make it possible to explain this death either as a result of inhibition of protein or RNA synthesis or as a result of the absence of amino acids. These possibilities were tested in experiments, in which the synthesis of proteins and RNA was inhibited by specific inhibitors in the presence of amino acids. Under these conditions no death of cells was detected, thus indicating that free amino acids play a role in the repair of radiation damage.

Amino Acids↗
PubMed1975

Participation of exogenous thymine and thymidine in deoxyribonucleic acid synthesis in Lactobacillus acidophilus.

The degree of participation (DP) of exogenous thymidine and thymine in overall DNA synthesis was studied in Lactobacillus acidophilus R-26. The DP of thymidine remains constant under a variety of conditions (except at low thymidine concentrations, when the DP is influenced by deoxyribonucleosides and folic acid). A 5-bromodeoxyuridine-resistant mutant was isolated, which displayed cross-resistance to 5-bromouracil and a significantly lower DP of thymidine than the parental strain. Thymine was poorly incorporated in the parental strain even in the presence of deoxyribosides. The results of this investigation would be compatible with the possibility of an alternative pathway for thymidylate synthesis other than the known thymidylate synthase pathway.

Bromodeoxyuridine↗
PubMed1975

Detection of Lactobacillus acidophilus in feces of humans, pigs, and chickens.

Lactobacilli in fecal material from humans, pigs, and chickens were enumerated on lactobacillus selective agar (LBS). In all samples, higher numbers of lac-tobacilli were detected when plates were incubated in a system flushed with CO2 rather than in air. Much higher numbers of bacteria from human feces were detected when the LBS agar plates were incubated anaerobically in a hydrogen-carbon dioxide atmosphere (GasPak) than when incubated in CO2. The bacteria from human feces isolated on LBS agar incubated anaerobically were predominately bifidobacteria. Cultures from all three sources isolated on LBS agar incubated under CO2 were lactobacilli, including Lactobacillus acidophilus. Differences were observed in biochemical characteristics of some of the L. acidophilus isolated from all three sources. Guanine plus cytosine base ratios of deoxyribonucleic acid isolated from L. acidophilus cultures from humans were lower, in most cases, than those from pigs and chickens.

Agar↗
PubMed1975

Enterotoxigenic intestinal bacteria in tropical sprue. IV. Effect of linoleic acid on growth interrelationships of Lactobacillus acidophilus and Klebsiella pneumoniae.

The factors responsible for colonization of the small intestine by enterotoxigenic coliform bacteria in Puerto Ricans with tropical sprue are unknown, but epidemiological observations have suggested that they may be related to an increased dietary intake of long-chain unsaturated fatty acids, particularly linoleic acid, which is known to exert an inhibitory effect on the growth of gram-positive organisms that normally comprise the flora of the small intestine. We have examined, by using a glucose-limited continuous-culture system, what effect this fatty acid exerts on the growth relationships of enteric gram-positive and coliform bacteria. In this system, colonization by an invading strain of Klebsiella pneumoniae was prevented by the presence of an established culture of Lactobacillus acidophilus, principally by virtue of a lowered pH of the medium that was incompatible with Klebsiella growth. However, when the population density of L. acidophilus was reduced by the presence of a sufficient concentration of linoleic acid, the invading K. pneumoniae successfully colonized the system and, once established, suppressed the growth of L. acidophilus. These observations indicate that, under the conditions of our chemostat, gram-positive enteric bacteria suppress coliform growth and that this effect is reversible by the presence of linoleic acid. It remains to be established, however, what pertinence these in vitro observations have to conditions within the intestinal tract of persons living in the tropics.

Enterotoxins↗