Babesia: the protective effects of killed Propionibacterium acnes on the infections of two rodent Babesia parasites in mice

In the present study, we investigated the protective effects of killed Propionibacterium acnes on the infections of two rodent Babesia parasites in mice. Pre-treatment with "EqStim" (a commercially available immunostimulant containing killed P. acnes) showed significant resistance to both infections. To elucidate the immunological status in the mice, the concentrations of multiple cytokines were measured in serum collected from infected mice. After B. microti infection, the levels of interleukin (IL)-2, IL-4, IL-5, IL-10, IL-12p70, and tumor necrosis factor (TNF)-alpha in the treated group were significantly lower than in the control group. In contrast, after B. rodhaini infection, only IL-12p70 and TNF-alpha were detectable at significantly higher levels in the treated group than in the control group. The present findings indicated the protective effects of killed P. acnes on rodent babesiosis even with different immune responses between the B. microti and B. rodhaini infections. Killed P. acnes might be a powerful tool for the control of serious livestock babesiosis.     

Analysis of clinical isolates of Propionibacterium acnes by optimised RAPD

Random amplification of polymorphic DNA (RAPD) was evaluated as a genotypic method for typing clinical strains of Propionibacterium acnes. RAPD can suffer from problems of reproducibility if parameters are not standardised. In this study the reaction conditions were optimised by adjusting template DNA concentration and buffer constituents. All isolates were typeable using the optimised RAPD protocol which was found to be highly discriminatory (Simpson's diversity index, 0.98) and reproducible. Typing of P. acnes by optimised RAPD is an invaluable tool for the epidemiological investigation of P. acnes for which no other widely accepted method currently exists.     

Peptides with antimicrobial and anti-inflammatory activities that have therapeutic potential for treatment of acne vulgaris

The pathogenesis of acne vulgaris is multifactorial involving infection of the pilosebaceous unit with Propionibacterium acnes and a cytokine-mediated inflammatory response. Five frog skin-derived antimicrobial peptides ([D4k]ascaphin-8, [G4K]XT-7, [T5k]temporin-DRa, brevinin-2GU, and B2RP-ERa), chosen for their low hemolytic activity against human erythrocytes, were assessed for their effects on the growth of clinical isolates of P. acnes and on the release of pro-inflammatory and anti-inflammatory cytokines from peripheral blood mononuclear (PBM) cells. All peptides inhibited the growth of P. acnes with the highest potency exhibited by [D4k]ascaphin-8 (minimum inhibitory concentration, MIC=3-12.5 μM). Release of TNF-α from concanavalin A (ConA)-stimulated PBM cells was significantly reduced by [D4k]ascaphin-8, [G4K]XT-7, brevinin-2GU, and B2RP-ERa (1 and 20 μg/ml) and by [T5k]temporin-DRa (20 μg/ml). Release of IFN-γ from unstimulated PBM cells was significantly reduced by [D4k]ascaphin-8 and brevinin-2GU (1 and 20 μg/ml). No peptide showed significant effects on Il-17 release. Release of the anti-inflammatory cytokines TGF-β, IL-4, and IL-10 from both unstimulated and ConA-treated PBM cells was significantly increased by [T5k]temporin-DRa and B2RP-ERa (1 and 20μg/ml). The potent activities of [D4k]ascaphin-8 and [T5k]temporin-DRa in inhibiting the growth of P. acnes and the release of pro-inflammatory cytokines, and in stimulating the release of anti-inflammatory cytokines suggest a possible therapeutic role in the treatment of acne vulgaris.     

痤疮丙酸杆菌的分离鉴定及其对瘤胃微生物发酵的影响

摘要：【目的】奶牛围产期能量代谢的特点是能量负平衡,瘤胃发酵产生的丙酸是奶牛糖异生供能的主要底物,对预防奶牛能量负平衡具有重要的意义。本研究旨在从健康奶牛瘤胃液中分离、筛选出以产丙酸为主的痤疮丙酸杆菌,研究其瘤胃发酵特性。【方法】无菌采取装有瘤胃瘘奶牛的瘤胃液,按照厌氧菌分离步骤,通过丙酸生成菌株的特异性培养基SLB进行筛选,提取分离菌的基因组DNA,克隆其16S rRNA基因,进行序列测定,分离出一株痤疮丙酸杆菌。通过体内外发酵试验研究痤疮丙酸杆菌对瘤胃液pH、挥发性脂肪酸和乳酸的影响。【结果】通过形态学观察、生化反应和序列分析证实所分离的一株产丙酸的杆菌为痤疮丙酸杆菌。该菌株在体外发酵过程中,瘤胃液pH先下降,在12h时降至最低,随后上升;乙酸、丙酸、丁酸等挥发性脂肪酸先升高,于12h时升至最高,随后又降低;乳酸浓度和乙酸/丙酸总体上一直下降;在体内发酵过程中,pH总体上下降;乙酸、丙酸、丁酸等挥发性脂肪酸总体上升。【结论】在国内首次从健康牛瘤胃液中成功分离出一株痤疮丙酸杆菌,为今后研发预防奶牛能量负平衡的微生态制剂奠定基础。     

基于高通量解析和可培养技术的白蔹内生真菌类群分析及分离菌株的抗痤疮致病菌活性

【背景】药用植物蕴含丰富的内生真菌类群资源,而且内生真菌可产生与宿主相关的次级代谢产物,具有多种生物活性,是活性化合物生产的潜在经济来源。【目的】分析药用植物白蔹根部内生真菌的物种多样性,并筛选出具有抗痤疮致病菌活性的目标菌株。【方法】基于高通量和组织分离法分析白蔹内生真菌的类群结构多样性;通过琼脂扩散法对内生真菌代谢产物的抗痤疮致病菌活性进行筛选;以微量肉汤稀释法测定代谢产物的最小抑菌浓度(minimuminhibitory concentration, MIC)和最小杀菌浓度(minimum bactericidal concentration, MBC)。【结果】高通量测序结果显示,白蔹根部内生真菌可注释到8门22纲45目73科93属,根部的优势属为Tainosphaeria(20.86%)和镰刀菌属(Fusarium, 15.38%)。基于组织分离法共从白蔹根部分离获得83株内生真菌,隶属于12个属,其中青霉属(Penicillium,24.10%)、木霉属(Trichoderma,14.46%)、背芽突霉属(Cadophora, 13.25%)、镰刀菌属(Fusarium, ...     

产酸丙酸杆菌生长特性及5L罐发酵动力学研究

论文在摇瓶水平对产酸丙酸杆菌基本生长特性（温度、pH、摇床转速、接种量、种龄等）、碳源、氮源利用情况、产物抑制及5 L罐发酵动力学进行了研究。结果表明,该菌在32℃,初始pH 6．5,摇床转速150 r/min,接种24 h的种子液,接种量为5％条件下,产酸丙酸杆菌生长及产酸水平达最高值;该菌可利用碳源十分广泛,但对氮源要求比较高,只可利用有机氮源;在不同初始葡萄糖浓度下,产酸丙酸杆菌生长及产酸水平差异不大,无明显底物抑制现象;在2g/L的初始丙酸盐浓度下,该菌生长受到明显抑制;在5L发酵罐中,初始葡萄糖浓度为58．8 g/L,发酵72 h,葡萄糖消耗完全,丙酸终浓度达22．4 g/L,丙酸得率和产率分别达0．381 g/g和0．295 g/（L·h）,丙酸占总酸比例达72．10％。     

Propionic acid production from glycerol by metabolically engineered Propionibacterium acidipropionici

Large amounts of crude glycerol produced in the biodiesel industry can be used as a low-cost renewable feedstock to produce chemicals and fuels. Compared to sugars (sucrose, glucose, xylose, etc.), glycerol has a lower reducing level, which is of benefit to the production of reduced chemicals. In this work, glycerol as the sole carbon source in propionic acid fermentation by metabolically engineered Propionibacterium acidipropionici (ACK-Tet) was studied. It was found that the adapted ACK-Tet mutant could use glycerol for its growth and produced propionic acid at a high yield of 0.54–0.71 g/g, which was much higher than that from glucose (0.35 g/g). In addition, the production of acetic acid in glycerol fermentation was much less than that from glucose. Thus, glycerol fermentation produced a high purity propionic acid with a high propionic acid to acetic acid ratio of 22.4 (vs. 5 for glucose fermentation), facilitating the recovery and purification of propionic acid from the fermentation broth. The highest propionic acid concentration obtained from glycerol fermentation was 106 g/L, which was 2.5 times of the highest concentration (42 g/L) previously reported in the literature.     

丙酸积累对薛氏丙酸杆菌生长及产酸的影响*

报道丙酸积累对维生素B12产生菌Propionibacterium shermanii生长及丙酸产生的影响,在初糖浓度6％,pH6.5的批次发酵条件下,测定了该菌的耗糖、产酸和茵体生长曲线。发酵24h后,培养基中添加1％、3％和6％的丙酸,发酵结束时菌体干重只有对照的75．2％、65．4％和52.9％,产酸是对照的79.3％、69．2％和39．3％。加入6％的丙酸不能完全抑制耗糖和产酸。部分解除丙酸抑制可使菌体干重增加60％。     

Biosynthesis of vitamin B12 by Propionibacterium freudenreichii subsp. shermanii ATCC 13673 using liquid acid protein residue of soybean as culture medium

Vitamin B12 deficiency still persists, mainly caused by low intake of animal food products affecting vegetarians, vegans, and populations of underdeveloped countries. In this study, we investigate the biosynthesis of vitamin B12 by potential probiotic bacterium using an agroindustry residue, the liquid acid protein residue of soybean (LAPRS), as a low-cost, animal derivate-free alternative culture medium. Cultures of Propionibacterium freudenreichii subsp. shermanii ATCC 13673 growing in LAPRS for vitamin B12 biosynthesis were studied using the Plackett–Burman experimental approach, followed by a central composite design 2² to optimize the concentration of significant variables. We also performed a proteolytic treatment of LAPRS and evaluated the optimized–hydrolyzed medium influence on the microbial growth and metabolism in shaker flask and bioreactor experiments. In this all-plant source medium, P. freudenreichii subsp. shermanii produced high concentrations of cells and high amounts of vitamin B12 (0.6 mg/g cells) after process optimization. These results suggest the possibility of producing vitamin B12 by a potential probiotic bacterium in a very cheap, animal derivate-free medium to address the needs of specific population groups, at the same time reducing the production costs of this essential vitamin.     

Presence of oxygen-consuming ribonucleotide reductase in corrinoid-deficientPropionibacterium freudenreichii

Corrinoid-deficient Propionibacterium freuden- reichii subsp. shermanii showed adenosylcobalamin-(AdoCbl)-independent ribonucleotide reductase (RNR) activity in the presence of air. Increasing the incubation time with free access of O₂ led to an increase in RNR activity. As polarographic estimations of O₂ uptake demonstrated, AdoCbl-independent RNR activity (with ADP as substrate) in a cell-free system of corrinoid-deficient P. freudenreichii was accompanied by specific molecular oxygen consumption. The activity was not inhibited by carbonyl cyanide m-chlorophenylhydrazone (CCCP) or carbonyl cyanide p-(trifluoromethoxy)phenylhydrazone (FCCCP). The activity was present in the cytoplasmic membrane-free soluble fraction of the cell extract, and it was inhibited by hydroxyurea. Manganese ions were important for the cell division of corrinoid-deficient P. freudenreichii and stimulated RNR activity after 8-hydroxyquinoline or EDTA treatment of the cell extract. We therefore concluded that P. freudenreichii is able to form DNA (deoxyribosylic precursors) using AdoCbl-dependent ribonucleotide reductase and also with an alternative AdoCbl-independent molecular-oxygen-consuming RNR system. Received: 29 May 1995 / Accepted: 14 August 1995