Complete genome sequence of Bifidobacterium bifidum S17

Here, we report on the first completely annotated genome sequence of a Bifidobacterium bifidum strain. B. bifidum S17, isolated from feces of a breast-fed infant, was shown to strongly adhere to intestinal epithelial cells and has potent anti-inflammatory activity in vitro and in vivo. The genome sequence will provide new insights into the biology of this potential probiotic organism and allow for the characterization of the molecular mechanisms underlying its beneficial properties.     

Growth of Bifidobacterium bifidum in whey-based media

Bifidobacteria play an important role in human health including the enhancement of resistance against infection in infants. To develop an inexpensive whey-based medium for Bifidobaterium bifidum, potential growth promoters — yeast extract, casein, bovine casein digest, tryptone, peptone and glucosamine — singly or in combinations, were evaluated for their bifidus growth-promoting activity. The effect of environmental conditions on growth in cheese whey was also evaluated. A whey-based medium for B. bifidum was formulated. Cheese whey supplemented with N-acetylglucosamine (1 mg/ml) and yeast extract (10 mg/ml) in the presence of sodium thioglycolate (0.1%) at pH 6.8 promoted the growth of B. bifidum at 37°C. Journal of Industrial Microbiology & Biotechnology (2000) 25, 177–179. Received 20 May 2000/ Accepted in revised form 20 July 2000     

Feruloyl oligosaccharides stimulate the growth of Bifidobacterium bifidum

Insoluble dietary fiber from wheat bran contains some feruloyl groups linked to the arabinose residues in the cell wall arabinoxylan. Treatment of wheat bran insoluble dietary fiber with xylanase from Bacillus subtilis yielded feruloyl oligosacchairdes, which were purified with Amberlite XAD-2. Saponification of the feruloyl oligosaccharides released ferulic acid and arabinoxylan oligosaccharides which consist of arabinose and xylose. The effect of the feruloyl oligosacchairdes on the growth of Bifidobacterium bifidum F-35 was investigated in vitro. The B. bifidum produced acid when cultivated anaerobically in TPY broth with 0.5% feruloyl oligosacchairdes as the carbohydrate source. The biomass yield of the B. bifidum increased with increasing the concentration of feruloyl oligosaccharides in TPY broth. The maximum cell growth was increased by 50% in TPY broth supplemented with 0.1% feruloyl oligosaccharides compared to TPY broth. These results indicated that the growth of B. bifidum F-35 was promoted by the feruloyl oligosaccharides from wheat bran insoluble dietary fiber, and not suppressed by the ferulic acid moiety of them.     

Optimal thermotolerance of Bifidobacterium bifidum in gellan-alginate microparticles

The purpose of this research was to encapsulate Bifidobacterium bifidum using gellan, sodium alginate and prebiotics as coating materials, and to maximize the thermotolerance of the probiotics with an optimal combination of the coating materials. The optimal ratio of the coating materials for the microparticles under heat treatments (75 degrees C, 1 min) was obtained by using the response surface method and the sequential quadratic programming technique. Optimization results indicated that 2% sodium alginate mixed with 1% gellan gum as coating materials would produce the highest thermotolerance in terms of B. bifidum count. The verification experiment yielded a result close to the predicted values, with no significant difference (P > 0.05). The results of heat treatments also demonstrated that the addition of gellan gum in the walls of probiotic microcapsules provided improved protection for B. bifidum. These probiotic counts remained at 10(5)-10(6) CFU/g for the microcapsules stored for 2 months, then treated in heat and in simulated gastric fluid.     

Complete genome sequence of Bifidobacterium longum subsp. longum KACC 91563

Bifidobacterium longum strains predominate in the colonic microbiota of breast-fed infants. Here we report the complete genome sequence of B. longum subsp. longum KACC 91563, isolated from feces of neonates. A single circular chromosome of 2,385,301 bp contains 1,980 protein-coding genes, 56 tRNA genes, and 3 rRNA operons.     

Complete genome sequence of Bifidobacterium animalis subsp. lactis BLC1

Bifidobacterium animalis subsp. lactis BLC1 is a probiotic bacterium that is widely exploited by food industries as the active ingredient of various functional foods. Here we report the complete genome sequence of B. animalis subsp. lactis BLC1, which is expected to provide insights into the biology of this health-promoting microorganism and improve our understanding of its phylogenetic relatedness with other members of the B. animalis subsp. lactis taxon.     

Genome Sequence of the Immunomodulatory Strain Bifidobacterium bifidum LMG 13195

In this work, we report the genome sequences of Bifidobacterium bifidum strain LMG13195. Results from our research group show that this strain is able to interact with human immune cells, generating functional regulatory T cells.     

两歧双歧杆菌对菌群失衡大鼠类风湿关节炎的调整作用

目的探讨两歧双歧杆菌对菌群失衡大鼠类风湿关节炎(RA)的调整作用。方法首先利用抗生素头孢曲松钠灌胃的方法建立大鼠(SPF级雌性Wistar大鼠20只)肠道菌群失衡模型,在此基础上采用牛Ⅱ型胶原诱导方法建立大鼠RA(CIA)模型,然后分为模型组和两歧双歧治疗组,3周后,观察两组大鼠关节肿胀程度,血清中IgG、IL-1β、TNF-α、IL-6、IL-17、IL-4、IL-10的变化及血清中SOD、MDA和滑膜液中SOD的变化。结果与模型组相比,治疗组的关节肿胀评分有降低趋势;血清中的IgG(t=6.0114,P=0.0002)、IL-1β(t=6.6719,P=0.0001)、TNF-α(t=3.8461,P=0.004)和IL-17(t=4.6894,P=0.001)的含量明显降低,IL-6略有降低,IL-4和IL-10都有所升高;血清中的SOD活力有所升高,MDA含量有所降低,滑膜液中的SOD(t=-2.4793,P=0.038)活力明显升高。结论两歧双歧杆菌能够减缓炎症和降低氧化压力,从而出现减轻关节肿胀、延缓RA发展的趋势。     

Aspects of iron metabolism in Bifidobacterium bifidum var. pennsylvanicus

• 1.1. Btfidobacterium bifidum var. Pennsylvanias requires ferrous iron for growth, and cannot utilize ferric iron even in the presence of siderophores.
• 2.2. Acid production by the microorganisms is dependent in part on iron content of the medium.
• 3.3. Heme and heme-containing proteins inhibit the microbial growth, and it is proposed that this is in part responsible for the change in the infant's intestinal flora upon weaning.
• 4.4. Bacterial growth inhibition brought about by heme cannot be restored by heme biosynthesis intermediates, and known heme biosynthesis inhibitors have no effect on bacterial growth. The basis for heme-induced microbial growth inhibition remains unclear.

     

Novel Characteristics of Bifidobacterium bifidum in Solid State Fermentation System

Summary The characteristics of Bifidobacterium bifidum grown in solid state fermentation (SSF) system (water content of media 54.5 and 68.8%) was compared with the submerged fermentation (SmF) system (water content of medium: 89.8%). Besides lactic acid (lactate) and acetic acid (acetate), the bacterium was able to secrete propionic acid (propionate) and butyric acid (butyrate) under SSF conditions. However, it only produced lactate and acetate under SmF conditions. The ratio of lactate to acetate was 1.26–1.62:1 in SSF but it was 1:2 in SmF. A higher content of C16:0 and C18:1 as well as a lower content of C18:0 cell membrane fatty acids were observed in SSF than in SmF. There was a lower growth rate, a lower viable count and a longer logarithmic growth phase for B. bifidum cultivated in SSF than in SmF.     

Dietary Mannan-oligosaccharides potentiate the beneficial effects of Bifidobacterium bifidum in broiler chicken

This study investigated the effects of dietary Bifidobacterium bifidum (BFD) and mannan-oligosaccharide (MOS), as a synbiotic, on the production performance, gut microbiology, serum biochemistry, antioxidant profile and health indices of broiler chicken. Six dietary treatments were T1 (negative control), T2 (positive control-20 mg antibiotic BMD kg⁻¹ diet; BMD: bacitracin methylene disalicylate), T3 (0·1% MOS + 10⁶ CFU BFD per g feed), T4 (0·1% MOS + 10⁷ CFU BFD per g feed), T5 (0·2% MOS + 10⁶ CFU BFD per g feed) and T6 (0·2% MOS + 10⁷ CFU BFD per g feed). Significantly (P < 0·01) better growth performance and efficiency was observed in birds supplemented with 0·2% MOS along with 10⁶ CFU BFD per g of feed compared to BMD and control birds. Supplementation with 0·2% MOS along with either 10⁶ or 10⁷ CFU BFD per g feed reduced (P < 0·01) the gut coliform, Escherichia coli, total plate count, and Clostridium perfringens count and increased the Lactobacillus and Bifidobacterium count. Significantly (P < 0·01) higher serum and liver antioxidant enzyme pool, serum HDL cholesterol and lower serum glucose, triglyceride, total cholesterol, cardiac risk ratio, atherogenic coefficient and atherogenic index of plasma were observed in birds supplemented with 0·2% MOS along with 10⁶ CFU BFD per g of feed compared to control or BMD supplemented birds. Better production performance, gut microbial composition, serum biochemistry, antioxidant profile and health indices were depicted by broiler chicken supplemented with 0·2% MOS and 10⁶ CFU BFD per g of feed.     

Complete genome sequence of human adenovirus prototype 17

As one of the first five human adenoviruses (HAdVs) to be sequenced, type 17 was important as a reference tool for comparative genomics of recently isolated HAdV pathogens in species D. HAdV-D17 was the first species D adenovirus to be sequenced and was deposited in GenBank in 1999. These genome data were not of high quality, and a redetermination of the same stock virus provides corrected data; among the differences are a length of 35,139 bp versus 35,100 bp in the original, and 160 mismatches to the original genome were found. Annotation of the coding sequences reveals 39 as opposed to 8, a finding which is important for phylogenomic studies.     

Structure of the lipoteichoic acids from Bifidobacterium bifidum spp. pennsylvanicum

The lipoteichoic acids from Bifidobacterium bifidum spp. pennsylvanicum were extracted from cytoplasmic membranes or from disintegrated bacteria with aqueous phenol and purified by gel chromatography. The lipoteichoic acid preparations contained phosphate, glycerol, galactose, glucose and fatty acids in a molar ratio of 1.0:1.0:1.3:1.2:0.3. Chemical analysis and NMR studies of the native preparations and of products from various acid and alkaline hydrolysis procedures gave evidence for the structure of two lipoteichoic acids. The lipid anchor appeared to be 3-O-(6'-(sn-glycero-1-phosphoryl)diacyl-beta-D-galactofuranosyl)-sn-1, 2-diacylglycerol. The polar part showed two structural features not previously described for lipoteichoic acids. A 1,2-(instead of the usual 1,3-) phosphodiester-linked sn-glycerol phosphate chain is only used substituted at the terminal glycerol unit with a linear polysaccharide, containing either beta(1----5)-linked D-galactofuranosyl groups or beta(1----6)-linked D-glucopyranosyl groups.     

Characterization of the Lactose Transport System in the Strain Bifidobacterium bifidum DSM 20082

Lactose was fermented but not assimilated by the strain Bifidobacterium bifidum DSM 20082. The sugar uptake was measured with lactose ¹⁴C. K _m and V _max values were respectively 2.6 mM and 12.11 nmol/min/mg of cell protein. The lactose transport system and the β-D-galactosidase were stimulated when the cells were grown with lactose, but isopropyl-β-D-thiogalactopyranoside had no effect. Lactose uptake was inhibited by compounds which interfered with proton and metal ionophore. Na⁺, Li⁺, or K⁺ did not affect incorporation of lactose. Furthermore, the lactose uptake decreased when an inhibitor of ATP synthesis was used. From the results of this study, the strain contained an active lactose transport system, probably a proton symport as described for Escherichia coli but with a different regulation system.     

Purification, amino acid sequence and mode of action of bifidocin B produced by Bifidobacterium bifidum NCFB 1454

Bifidocin B produced by Bifidobacterium bifidum NCFB 1454 was purified to homogeneity by a rapid and simple three step purification procedure which included freeze drying, Micro-Cel adsorption/desorption and cation exchange chromatography. The purification resulted in 18% recovery and an approximately 1900-fold increase in the specific activity and purity of bifidocin B. Treatment with bifidocin B caused sensitive cells to lose high amounts of intracellular K+ ions and u.v.-absorbing materials, and to become more permeable to ONPG. Bifidocin B adsorbed to the Gram-positive bacteria but not the Gram-negative bacteria tested. Its adsorption was pH-dependent but not time-dependent. For sensitive cells, the adsorption and lethal action of bifidocin B was very rapid. In 5 min, 95% of bifidocin B adsorbed onto sensitive cells. Several salts inhibited the binding of bifidocin B, which could be overcome by increasing the amount of bifidocin B added. Pre-treatment of sensitive cells and cell walls with detergents, organic solvents or enzymes did not cause a reduction in subsequent cellular binding of bifidocin B, but cell wall preparations treated with methanol:chloroform and hot 20% (w/v) TCA lost the ability to adsorb bifidocin B. Also, the addition of purified heterologous lipoteichoic acid to sensitive cells completely blocked the adsorption of bifidocin B. The amino acid sequence indicated that the bacteriocin contained 36 residues. N-terminal amino acid sequence analysis yielded a sequence of KYYGNGVTCGLHDCRVDRGKATCGIINNGGMWGDIG. Curing experiments with 20 micrograms ml-1 acriflavine yielded cell derivatives that no longer produced bifidocin B but retained immunity to bifidocin B. Production of bifidocin B, but not immunity to bifidocin B, was associated with a plasmid of about 8 kb in this strain.     

High concentration cultivation of Bifidobacterium bifidum in a submerged membrane bioreactor

In batch cultures, after 25 h, the maximum cell mass of Bifidobacterium bifidum BGN4 was 4.5 g/L, and the maximum cell count was 3.0 x 10(9) cfu/mL at pH 6.0 and 50 g/L sucrose. To increase the viable counts of bifidobacteria, cell retentive culture was applied using a submerged membrane bioreactor with suction and gas sparging. The maximum mass, count, and productivity of the cells after 36 h were 12.0 g/L, 2.2 x 10(10) cfu/mL, and 6.1 x 10(8) cfu/mL x h, respectively, at the feeding (dilution) rate of 120 mL/h (0.06 h-1) in the feeding medium. The accumulated levels of organic acids and ammonium ions at the end of the cultivation were 1.5 and 1.0 g/L, respectively. The viable counts and volumetric productivity of the cells after the cell retentive culture were 7.3- and 5.1-fold higher, respectively, than the values obtained during batch culture. These high viable counts and volumetric productivities were obtained by maintaining lower concentrations of organic acids and ammonium ions so that the growth of B. bifidum BGN4 was not inhibited. The submerged membrane bioreactor produced the highest viable counts of B. bifidum without membrane fouling and cell damage.     

Unraveling the Leloir Pathway of Bifidobacterium bifidum: Significance of the Uridylyltransferases

The GNB/LNB (galacto-N-biose/lacto-N-biose) pathway plays a crucial role in bifidobacteria during growth on human milk or mucin from epithelial cells. It is thought to be the major route for galactose utilization in Bifidobacterium longum as it is an energy-saving variant of the Leloir pathway. Both pathways are present in B. bifidum, and galactose 1-phosphate (gal1P) is considered to play a key role. Due to its toxic nature, gal1P is further converted into its activated UDP-sugar through the action of poorly characterized uridylyltransferases. In this study, three uridylyltransferases (galT1, galT2, and ugpA) from Bifidobacterium bifidum were cloned in an Escherichia coli mutant and screened for activity on the key intermediate gal1P. GalT1 and GalT2 showed UDP-glucose-hexose-1-phosphate uridylyltransferase activity (EC 2.7.7.12), whereas UgpA showed promiscuous UTP-hexose-1-phosphate uridylyltransferase activity (EC 2.7.7.10). The activity of UgpA toward glucose 1-phosphate was about 33-fold higher than that toward gal1P. GalT1, as part of the bifidobacterial Leloir pathway, was about 357-fold more active than GalT2, the functional analog in the GNB/LNB pathway. These results suggest that GalT1 plays a more significant role than previously thought and predominates when B. bifidum grows on lactose and human milk oligosaccharides. GalT2 activity is required only during growth on substrates with a GNB core such as mucin glycans.     

Effects of Bifidobacterium bifidum on adaptive immune senescence in aging mice

Bifidobacteria are a natural component of the bacterial flora of the human body and have a symbiotic bacteria-host relationship with human beings. Aging is associated with reduced numbers of beneficial colonic Bifidobacteria and impaired immunity. The possible anti-senescence effects of Bifidobacteria are presently unknown. The aims of the present study were to investigate possible anti-senescence effects of B. bifidum on naturally senescent mice and to explore their mechanisms. After treatment with B. bifidum, mice were killed and samples collected. Cytokine production in serum and lymphocyte culture supernatant, anti-oxidation activity and gene expression were measured. B. bifidum significantly increased cytokine IL-2 and IFN-γ levels but decreased proinflammatory cytokines IL-6 and TNF-α concentrations. Moreover, B. bifidum improved anti-oxidation activity and reduced lipid peroxidation in thymus and spleen. In addition, B. bifidum down-regulated p16 expression in thymus and spleen. Taken together, the results indicate, for the first time, that B. bifidum delays senescence by several mechanisms, including enhancement of anti-oxidation activity in thymus and spleen, alteration of gene expression and improvement in immune function.     

Influence of nutrition on the morphology of a strain of Bifidobacterium bifidum

A mucoid variant of Bifidobacterium bifidum was converted from its normal curved rod or bifid form to a highly branched form when grown in a chemically defined minimal medium. Branching could be prevented by the addition of a mixture of dl-alanine, dl-aspartic acid, l(+)-glutamic acid, and dl-serine, but not when any one of these four amino acids was omitted. Although sodium chloride induced pleomorphism, calcium ions were ineffective in suppressing the appearance of these pleomorphic forms. None of the cell wall precursors tested, viz., N-acetyl-d-glucosamine, alpha-epsilon-diaminopimelic acid, and muramic acid, inhibited branching.