阴道液中唾液酸酶活性、阴道加德纳菌及其IgA水平的相关性研究

目的探讨阴道液中唾液酸酶活性、阴道加德纳菌及抗阴道加德纳菌的溶血素(anti-Gvh)IgA水平在细菌性阴道病(BV)的相关性。方法对15例健康人和60例临床诊断为BV的患者,取阴道分泌物分别进行唾液酸酶活性和anti-Gvh IgA水平测定及阴道加德纳菌(Gv)分离培养。唾液酸酶活性利用从底物-5溴-4氯-3吲哚基-α-D-N乙酰基神经氨酸(X-Neu5Ac)转化而得到的甲氧基苯酚的纳摩尔数来表示;anti-Gvh IgA通过ELISA法测定。结果BV组Gv活菌数(6.96 log CFU/g)显著高于健康对照组(2.58 log CFU/g)(P<0.01)。BV组anti-GvhIgA(238.0±220.6)显著高于健康对照组(175.0±40.16)(P<0.01)。BV组Gv分离率(86.7%)显著高于健康对照组(33.3%)(P<0.01)。45例临床诊断为BV的患者中,其中26例Gvh IgA(+),19例Gvh IgA(-);Gvh IgA(-)组阴道液中唾液酸酶活性(5.00±1.29)显著高于Gvh IgA(+)组(1.58±1.22)(P<0.01),2组的Gv的分离率和活菌数差异却没有显著性(P>0.05)。结论BV患者阴道内高活性的唾液酸酶与低水平anti-Gvh IgA和黏膜IgA破坏程度具有关联性。     

Lactobacillus plantarum: Microfiltration experiments for the production of probiotic biomass to be used in food and nutraceutical preparations

Several studies have focused their attention on increasing the production of lactobacillus ssp. (LAB) biomass via‐fermentation, in particular exploiting novel in situ product removal bioreactors that prevent accumulation of lactic acid, and therefore growth inhibition. Lactobacillus plantarum is one of the most studied species, used in nutritional supplements and in food processing. This research aimed to obtain high cell densities of L. plantarum, through fed‐batch and microfiltration experiments. The latter achieved a 5‐fold higher biomass density compared with batch experiments. Furthermore, the L. plantarum strain, isolated from Portoguese chorizo, was characterized for its ability to survive simulated digestion in vitro and competition potential toward certain common pathogens. Finally, the possibility of exploiting dairy liquid wastes (whey) as medium components was also explored demonstrating the strain's capability of metabolizing bovine‐ovine whey. This finding might be relevant in liquid waste treatments of diary industries that are well distributed in our region. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 31:325–333, 2015     

Ensiling whole-crop wheat and corn in large containers with Lactobacillus plantarum and Lactobacillus buchneri

The effect of applying Lactobacillus buchneri, alone or in combination with Lactobacillus plantarum, at ensiling, on the aerobic stability of wheat and corn silages was studied in 50-l plastic containers. Treatments comprised control (no additives), L. plantarum, L. buchneri and a combination of L. plantarum+L. buchneri. After 3 months of storage, the wheat silages treated with L. buchneri had higher acetic acid contents than the control or L. plantarum-treated silages, and were free of mold, whereas the top layers of the control or L. plantarum-treated silages were moldy. In an aerobic stability test the L. buchneri-treated silages were stable, whereas those treated with L. plantarum deteriorated. In the corn silages the effects of L. buchneri were not as clear and the top layer was moldy in all silages. However, L. buchneri also improved the aerobic stability of the corn silage, as indicated by lower yeast numbers, less CO₂ production and stable pH. It is concluded that L. buchneri has a potential as a silage additive that protects the silage upon aerobic exposure. The 50-l plastic containers can serve as an appropriate model to test silage additives before conducting full-scale farm experiments. Journal of Industrial Microbiology & Biotechnology (2002) 28, 7–11 DOI: 10.1038/sj/jim/7000207 Received 17 April 2001/ Accepted in revised form 25 August 2001     

Antiobesity effect of trans-10,cis-12-conjugated linoleic acid-producing Lactobacillus plantarum PL62 on diet-induced obese mice

AIMS: To observe the antiobesity activity of trans-10,cis-12-conjugated linoleic acid (CLA)-producing lactobacillus in mice. METHODS AND RESULTS: Lactobacillus plantarum PL62, which can grow in the presence of linoleic acid, was selected and studied. The culture supernatant of Lact. plantarum PL62 contained trans-10,cis-12-conjugated linoleic acid (6.4 microg ml(-1)), and the crude enzyme prepared from washed cells produced trans-10,cis-12 CLA (1395 microg mg(-1) protein). Lact. plantarum PL62 reduced the weights of epididymal, inguinal, mesenteric, and perirenal white adipose tissues and significantly reduced the blood levels of total glucose and body weights of mice (P<0.01). CONCLUSIONS: trans-10,cis-12-CLA-producing Lact. plantarum PL62 can exert the same antiobesity activity as trans-10,cis-12-CLA in mice. SIGNIFICANCE AND IMPACT OF THE STUDY: trans-10,cis-12-CLA-producing Lactobacillus can be a replacement for CLA for obesity treatment via the continuous production of trans-10,cis-12-CLA. The results provide a novel opportunity to develop foods with antiobesity activity.     

Biological control of bacterial plant diseases with Lactobacillus plantarum strains selected for their broad‐spectrum activity

The use of lactic acid bacteria (LAB) to control multiple pathogens that affect different crops was studied, namely, Pseudomonas syringae pv. actinidiae in kiwifruit, Xanthomonas arboricola pv. pruni in Prunus and Xanthomonas fragariae in strawberry. A screening procedure based on in vitro and in planta assays of the three bacterial pathogens was successful in selecting potential LAB strains as biological control agents. The antagonistic activity of 55 strains was first tested in vitro and the strains Lactobacillus plantarum CC100, PM411 and TC92, and Leuconostoc mesenteroides CM160 and CM209 were selected because of their broad‐spectrum activity. The biocontrol efficacy of the selected strains was assessed using a multiple‐pathosystem approach in greenhouse conditions. L. plantarum PM411 and TC92 prevented all three pathogens from infecting their corresponding plant hosts. In addition, the biocontrol performance of PM411 and TC92 was comparable to the reference products (Bacillus amyloliquefaciens D747, Bacillus subtilis QST713, chitosan, acibenzolar‐S‐methyl, copper and kasugamycin) in semi‐field and field experiments. The in vitro inhibitory mechanism of PM411 and TC92 is based, at least in part, on a pH lowering effect and the production of lactic acid. Moreover, both strains showed similar survival rates on leaf surfaces. PM411 and TC92 can easily be distinguished because of their different multilocus sequence typing and random amplified polymorphic DNA profiles.     

The biotechnological potential of subtilisin‐like fibrinolytic enzyme from a newly isolated Lactobacillus plantarum KSK‐II in blood destaining and antimicrobials

An antimicrobial oxidative‐ and SDS‐stable fibrinolytic alkaline protease designated as KSK‐II was produced by Lactobacillus plantarum KSK‐II isolated from kishk, a traditional Egyptian food. Maximum enzyme productivity was obtained in medium containing 1% lactose and 0.5% soybean flour as carbon and nitrogen sources, respectively. Purification of enzyme increased its specific activity to 1,140‐fold with a recovery of 33% and molecular weight of 43.6 kDa. Enzyme activity was totally lost in the presence of ethylenediaminetetraacetic acid and was restored after addition of Fe²⁺ suggesting that KSK‐II is a metalloprotease and Fe²⁺ acts as cofactor. Enzyme hydrolyzed not only the natural proteins but also synthetic substrates, particularly Suc‐Ala‐Ala‐Pro‐Phe‐pNA. KSK‐II can hydrolyze the Lys‐X easier than Arg‐X; thus, it was considered as a subtilisin‐family protease. Its apparent K_m, V_max, and K_cat were 0.41 mM, 6.4 µmol mg^?1 min^?1, and 28.0 s^?1, respectively. KSK‐II is industrially important from the perspectives of its maximal activity at 50°C (stable up to 70°C), ability to function at alkaline pH (10.0), stability at broad pH ranges (7.5–12.0) in addition to its stability toward SDS, H₂O₂, organic solvents, and detergents. We emphasize for the first time the potential of fibrinolytic activity for alkaline proteases used in detergents especially in blood destaining. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 31:316–324, 2015