Effects of three strains of bifidobacteria on cholesterol

To determine the validity of the hypothesis of assimilation or precipitation of cholesterol by Bifidobacterium species, resting cell assays and cultures were undertaken in TPY medium containing oxgall. With resting cell assays (pH 5), cholesterol was precipitated and redissolved in phosphate buffer (pH 7). At the end of the cultures, only part of the removed cholesterol from the culture medium was found in the phosphate buffer, while the missing cholesterol was in cell extracts. It appeared that removal of cholesterol during culturing was not solely due to its precipitation. It is concluded that growing bifidobacteria cells are able to remove cholesterol both by precipitation and assimilation.     

Evolutionary development and co-phylogeny of primate-associated bifidobacteria

In recent years, bifidobacterial populations in the gut of various monkey species have been assessed in several ecological surveys, unveiling a diverse, yet unexplored ecosystem harbouring novel species. In the current study, we investigated the species distribution of bifidobacteria present in 23 different species of primates, including human samples, by means of 16S rRNA microbial profiling and internal transcribed spacer bifidobacterial profiling. Based on the observed bifidobacterial-host co-phylogeny, we found a statistically significant correlation between the Hominidae family and particular bifidobacterial species isolated from humans, indicating phylosymbiosis between these lineages. Furthermore, phylogenetic and glycobiome analyses, based on 40 bifidobacterial species isolated from primates, revealed that members of the Bifidobacterium tissieri phylogenetic group, which are typical gut inhabitants of members of the Cebidae family, descend from an ancient ancestor with respect to other bifidobacterial taxa isolated from primates.     

DNA damage and repair in the steps for obtaining biopreparations

The change in the number of single-strand breaks in the genome of E. coli cells was being studied during centrifugation and drying of biomass used as raw material for producing biopreparations. The results obtained allowed the authors: (1) to establish the value of DNA damage at the two stages mentioned above and to reveal that structural integrity of the genome is mostly damaged if the humidity of dried biomass is below 15%; (2) to demonstrate that the repair of bacterial genome damages occurs after centrifugation and superficial dehydration, but it is not observed after deep dehydration.     

Lipoteichoic acids in lactobacillus strains that colonize the mouse gastric epithelium

[This corrects the article on p. 302 in vol. 52.].     

Effect of bifidobacteria and lactobacillus and antibiotics in combination with common gnotobiological isolation on the survival of mice with acute radiation sickness

The influence of the combined use of bacterial preparations (Bifidobacterium and Lactobacillus) and antibiotics (ciprofloxacin, lomefloxacin and amikacin) on the survival rate of irradiated mice placed under the conditions of general gnotobiological isolation was studied. Bacterial strains used in combination with quinolones (ciprofloxacin, lomefloxacin) significantly increased the mean survival time of the animals (p < 0.05) when introduced in a dose of 1.0 x 10(9) microbial cells per mouse on days 1, 3, 5, 7, 9, 11, 13 and 15 after irradiation. At the same time a short course of treatment with bacterial preparations (two injections on days 5 and 7 after irradiation) proved to be insufficient for increasing the survival rate of the animals. The mean survival time of the irradiated mice was higher after the use of bacterial preparations in combination with lomefloxacin or ciprofloxacin than after their use with amikacin.     

乳杆菌耐胆汁、降解结合胆盐和同化胆固醇能力的研究

对8株植物乳杆菌的胆汁耐受力、降解结合胆盐能力以及同化胆固醇能力进行了研究。不同的菌株在添加了牛胆汁的MRS中生长速度具有明显差异,同化胆固醇能力也明显不同,而降解结合胆盐的能力没有明显区别。分析发现,菌株的胆汁耐受力和降解结合胆盐能力,胆汁耐受力和同化胆固醇能力,以及降解结合胆盐能力和同化胆固醇能力之间都没有明显的相关性。     

Susceptibility of bifidobacteria to lysozyme as a possible selection criterion for probiotic bifidobacterial strains

Resistance or susceptibility of bifidobacteria to lysozyme and growth of bifidobacteria in human milk were tested. Susceptible bifidobacterial strains stopped their growth almost immediately after the addition of lysozyme (400 μg/ml), moderately susceptible strains exhibited reduced growth rate, and growth curves of resistant strains were not affected. Strains of human origin were more resistant to lysozyme than animal strains. While strains of B. bifidum grew well in human milk samples, the growth B. animalis strains was inhibited after inoculation to human milk. The resistance to lysozyme seems to be a promising criterion for the selection of new probiotic bifidobacterial strains.     

Production of succinic Acid from citric Acid and related acids by lactobacillus strains

A number of Lactobacillus strains produced succinic acid in de Man-Rogosa-Sharpe broth to various extents. Among 86 fresh isolates from fermented cane molasses in Thailand, 30 strains (35%) produced succinic acid; namely, 23 of 39 Lactobacillus reuteri strains, 6 of 18 L. cellobiosus strains, and 1 of 6 unidentified strains. All of 10 L. casei subsp. casei strains, 5 L. casei subsp. rhamnosus strains, 6 L. mali strains, and 2 L. buchneri strains did not produce succinic acid. Among 58 known strains including 48 type strains of different Lactobacillus species, the strains of L. acidophilus, L. crispatus, L. jensenii, and L. parvus produced succinic acid to the same extent as the most active fresh isolates, and those of L. alimentarius, L. collinoides, L. farciminis, L. fructivorans (1 of 2 strains tested), L. malefermentans, and L. reuteri were also positive, to lesser extents. Diammonium citrate in de Man-Rogosa-Sharpe broth was determined as a precursor of the succinic acid produced. Production rates were about 70% on a molar basis with two fresh strains tested. Succinic acid was also produced from fumaric and malic acids but not from dl-isocitric, alpha-ketoglutaric, and pyruvic acids. The present study is considered to provide the first evidence on the production of succinic acid, an important flavoring substance in dairy products and fermented beverages, from citrate by lactobacilli.     

Bio-electrosprays: the development of a promising tool for regenerative and therapeutic medicine

Regenerative and therapeutic medicine are two fields of research to which engineering sciences are increasingly contributing. One such case in which physical sciences have been greatly involved is in the generation of tissues by directly processing living cells. In this article we focus on the current status of cell or tissue engineering approaches by way of jets, particularly focusing on bio-electrosprays.     

Search for new cyclic AMP-binding proteins

Today, there is evidence that the cAMP-dependent kinases (PKA) are not the only intracellular receptors involved in intracellular cAMP signalling in eukaryotes. Other cAMP-binding proteins have been recently identified, including some cyclic nucleotide-gated channels and Epac (exchange protein directly activated by cAMP) proteins. All these proteins bind cAMP through conserved cyclic nucleotide monophosphate-binding domains. However, all putative cAMP-binding proteins having such domains, as revealed by computer analysis, do not necessarily bind cAMP, indicating that their presence is not a sufficient criteria to predict cAMP-binding property for a protein.     

Biological characteristics of strains of lactobacilli, promising for use as eubiotics]

In the course of in vitro studies 3 Lactobacillus strains with pronounced antagonistic activity against some pathogenic and opportunistic bacteria (shigellae, enteropathogenic Escherichia, Proteus, staphylococci) were selected. In experiments on germ-free rats faint colonization by L. plantarum 37 was observed in the small intestine, as well as in the large intestine when low doses of these bacilli were introduced into the gastrointestinal tract of the animals. In vitro experiments demonstrated the decreased growth rate of this strain. The prophylactic administration of two eubiotic strains, L. plantarum 37 and L. fermentum 39, simultaneously with chloramphenicol to primates inhibited the growth of opportunistic bacteria, though L. fermentum 39 excessively suppressed the content of Escherichia coli in the enterobacterial population. The optimum biological effect was achieved with the therapeutic use of these three strains for the correction of dysbiotic disturbances caused by the administration of tetracycline in volunteers.     

Search for new natural sources of morphinans

Codeine, medically the most widely used opiate, is mostly derived from morphine, isolated from opium and poppy straw (Papaver somniferum, opium poppy). Morphine, however, is greatly misused by illegal conversion into its diacetyl-derivative: heroin. The discovery of an efficient alternative medicine or a source for codeine other than opium poppy may contribute to a curtailment of the heroin market. No major adverse properties should be present in such a new medicine or codeine source. In this paper the search for the latter is discussed with regards to the natural occurrence of morphinan derivatives and the biosynthetic pathways in available plants. Economic and social problems connected with the introduction of a new biological source for opiates are reviewed.     

The enzyme activity of bacilli showing promise for incorporation into biopreparations

The enzymic activity (amalyse, protease, lipase, pectolytic and cellulase) has been studied in 5 strains of aerobic spore-forming bacteria (Bacillus subtilis, B. licheniformis, B. coagulans, B. pumilis, B. badius) being of interest for creation of medical and prophylactic biopreparations. The above-mentioned enzymes were found in some studied strains. This may provide participation of bacilli in the degradation processes of a number of substrates in the digestive tract of a human being and animals and is an advantage of preparations from the genus Bacillus bacteria as compared with the available biopreparations of other microbial cultures for prophylaxis and treatment of gastrointestinal diseases.