双歧杆菌四联活菌片中嗜酸乳杆菌的分离及生长动力学研究

目的以双歧杆菌四联活菌片为实验材料,利用酸化的MRS培养基筛选分离得到嗜酸乳杆菌,对其进行进一步的生长动力学研究,确定嗜酸乳杆菌的生长数学模型。方法通过浓度梯度稀释法利用改良MRS培养基对双歧杆菌四联活菌片中的嗜酸乳杆菌进行分离,利用分光光度仪和平板菌落计数两种不同的方法测定嗜酸乳杆菌在发酵过程中不同发酵时间的细胞浓度的动态变化,经软件处理后拟合出嗜酸乳杆菌细胞生长的Logistic数学模型。结果Logistic方程能很好地拟合嗜酸乳杆菌细胞生长的动态变化,并得到嗜酸乳杆菌在本实验条件下的数学模型,为进一步研究、利用嗜酸乳杆菌生长能力、产酸能力和产香能力等具有重要的理论指导意义。     

富硒转白细胞介素2基因双歧杆菌对小鼠移植瘤H22的治疗作用

目的评价富硒和转白细胞介素2（IL2）基因双歧杆菌对小鼠移植瘤H22的抑制效果。方法通过电转导将含IL2质粒导入到长双歧杆菌（Bifidobacterium longum,B.longum）中,将转IL2基因双歧杆菌接种到添加了亚硒酸钠（Na2SeO3）的培养基中,利用微生物的富集及转化作用,形成富硒的含IL2基因质粒的双歧杆菌（Se-B.longum-IL2）。结果利用双歧杆菌的肿瘤厌氧区靶向性,通过荷肝癌H22的小鼠尾静脉注射Se-B.longum-IL2,取得了良好的抑瘤效果与荷肝癌小鼠生存延长效果。结论转IL2基因双歧杆菌和富硒联合后对小鼠肝癌有明显的基因治疗前景。     

乳酸菌固体制剂计数方法研究

从培养基、稀释剂的角度对乳酸菌固体制剂样品进行计数方法比较。昂立1号○R优菌多颗粒样品中嗜酸乳杆菌在改良MC培养基上培养(72±3)h后菌落形态非常小,很难进行计数,在改良MC培养基中添加0.1%吐温80将会刺激嗜酸乳杆菌的生长,利于计数;采用MRS液体溶解复水10~15 m in、0.1%蛋白胨盐水稀释的计数结果明显高于直接采用生理盐水复水、稀释方法,两者差异有非常显著性。     

鱼腥草对硒的生物富集作用的研究

在相同pH值不同浓度的Na2SeO3和不同pH值相同浓度的Na2SeO3的Hoagland—Snyer溶液,培养天然鱼腥草一段时间。观察鱼腥草的生长情况,测定其体内总的硒量和无机硒含量。得出:鱼腥草在pH5 5、Na2SeO3浓度为20mg·L-1时,植株不仅茎、叶生长好,而且体内总的硒量较多,为322mg·kg-1。无机硒量较少,仅有59 4mg·kg-1。从而有机硒含量为262 6mg·kg-1,硒在体内的转化率达81%。表明pH5 5、Na2SeO3浓度为20mg·L-1,是溶液培养富硒鱼腥草的适宜环境条件之一。     

嗜酸乳杆菌同化MRS培养基中胆固醇能力的研究

目的 对嗜酸乳杆菌在MRS液体培养基中同化胆固醇的能力进行初步研究。方法模拟人体不同胆固醇水平。结果 嗜酸乳杆菌对低胆固醇或正常水平胆固醇同化作用不明显,而对高胆固醇水平的同化作用比较明显。结论 嗜酸乳杆菌具有同化胆固醇的能力。     

富硒螺旋藻培养技术研究

采用富硒技术对印项螺旋藻培养进行强化,对硒（IV）浓度和亚硫酸盐的影响,以及硒的生物富集及其对藻细胞分子官能团结构的影响等进行了较为详细的研究,并对相关的可能机理进行了讨论。研究发现,硒对印顶螺旋藻生长具有刺激或抑制的双重作用。在0.02mg/L-411.00mg/L浓度范围内,硒不仅可以加快印顶螺旋藻的生长,而且还可以提高其生物量;同时,钝顶螺旋藻对硒的事集随着硒浓度的增加而增加,较为缓慢的生长利于钝顶螺旋藻对硒的富集。研究还证实,NaSO3会减轻高浓度Na2SeO3对印顶螺旋藻生长的毒性,富硒培养不会对藻细胞分子官能团结构产生损害。实验得出钝顶螺旋藻富硒培养较佳的硒处理浓度在10mg／L－40mg／L。     

Na2SeO3对蚕豆根尖细胞遗传损伤作用的研究

采用蚕豆根尖微核实验和姊妹染色单体交换实验,研究亚硒酸钠(0.01～10.0 mg·L-1)对蚕豆根尖细胞的遗传损伤效应.结果表明一定浓度的亚硒酸钠(Na2SeO3)可导致蚕豆根尖细胞有丝分裂指数下降,间期细胞微核频率明显增高,且Na2SeO3的上述效应具有一定的剂量效应关系;同时Na2SeO3可诱导细胞姊妹染色单体交换(SCE)频率显著增高.研究表明,亚硒酸钠对蚕豆根尖细胞具有遗传毒害作用,并有可能对人体产生遗传损伤.     

嗜酸乳杆菌抑菌特性的研究

目的：对从婴儿肠道中分离出来的两株嗜酸乳杆菌的抑菌特性进行研究。方法：采用MRS培养基。结果：嗜酸乳杆菌对致病性大肠埃希菌、金黄色葡萄球菌以及炭疽杆菌有明显的抑菌作用。37℃培养24h抑菌圈大小均在15mm以上。结论：该菌是肠道中的益生菌。     

亚硒酸钠诱导SW480细胞凋亡过程中活性氧的作用

为探讨亚硒酸钠诱导人结肠癌SW480细胞凋亡的机理,将荧光探针2′,7′－二氯荧光黄乙二脂（2′,7′－DCFH－DA）、罗丹明123（rhodamine123）负载人结肠癌细胞,利用多光子成像系统测定胞内活性氧（ROS）、线粒体跨膜电位（△Ψm）的变化。结果发现（1）Na2SeO3作用SW480细胞,可导致细胞凋亡和胞内的ROS增加。SOD、过氧化氢酶可降低凋亡率并抑制ROS的增加。（2）线粒体电子传递链抑制剂鲁藤酮及氰化钠可抑制OS增加。（3）Na2SeO3可导致线粒体的跨膜电位的下降。表明Na2SeO3作用细胞可导致来源于线粒体的ROS增加,ROS介导亚硒酸钠诱导细胞凋亡。     

异麦芽寡糖对双歧杆菌生长促进作用的体外试验

用添加５％异麦芽寡糖的四种培养基观察对双歧杆菌等５种细菌的生长促进作用。结果显示,在营养较丰富的培养基中对双歧杆菌生长促进作用不显著;在营养较差的培养基中显著（Ｐ＜０．０５）,对嗜酸乳杆菌也显著,而对大肠杆菌、脆弱类杆菌和艰难梭菌不显著。     

On the origin of the Hirudinea and the demise of the Oligochaeta

The phylogenetic relationships of the Clitellata were investigated with a data set of published and new complete 18S rRNA gene sequences of 51 species representing 41 families. Sequences were aligned on the basis of a secondary structure model and analysed with maximum parsimony and maximum likelihood. In contrast to the latter method, parsimony did not recover the monophyly of Clitellata. However, a close scrutiny of the data suggested a spurious attraction between some polychaetes and clitellates. As a rule, molecular trees are closely aligned with morphology-based phylogenies. Acanthobdellida and Euhirudinea were reconciled in their traditional Hirudinea clade and were included in the Oligochaeta with the Branchiobdellida via the Lumbriculidae as a possible link between the two assemblages. While the 18S gene yielded a meaningful historical signal for determining relationships within clitellates, the exact position of Hirudinea and Branchiobdellida within oligochaetes remained unresolved. The lack of phylogenetic signal is interpreted as evidence for a rapid radiation of these taxa. The placement of Clitellata within the Polychaeta remained unresolved. The biological reality of polytomies within annelids is suggested and supports the hypothesis of an extremely ancient radiation of polychaetes and emergence of clitellates.     

On the ontogeny of the haptor and the evolution of the Monogenea

Data on the ontogeny of the posterior haptor of monogeneans were obtained from more than 150 publications and summarised. These data were plotted into diagrams showing evolutionary capacity levels based on the theory of a progressive evolution of marginal hooks, anchors and other attachment components of the posterior haptor in the Monogenea (Malmberg, 1986). 5 + 5 unhinged marginal hooks are assumed to be the most primitive monogenean haptoral condition. Thus the diagrams were founded on a 5 + 5 unhinged marginal hook evolutionary capacity level, and the evolutionary capacity levels of anchors and other haptoral attachement components were arranged according to haptoral ontogenetical sequences. In the final plotting diagram data on hosts, type of spermatozoa, oncomiracidial ciliation, sensilla pattern and protonephridial systems were also included. In this way a number of correlations were revealed. Thus, for example, the number of 5 + 5 marginal hooks correlates with the most primitive monogenean type of spermatozoon and with few sensillae, many ciliated cells and a simple protonephridial system in the oncomiracidium. On the basis of the reviewed data it is concluded that the ancient monogeneans with 5 + 5 unhinged marginal hooks were divided into two main lines, one retaining unhinged marginal hooks and the other evolving hinged marginal hooks. Both main lines have recent representatives at different marginal hook evolutionary capacity levels, i.e. monogeneans retaining a haptor with only marginal hooks. For the main line with hinged marginal hooks the name Articulon-choinea n. subclass is proposed. Members with 8 + 8 hinged marginal hooks only are here called Proanchorea n. superord. Monogeneans with unhinged marginal hooks only are here called Ananchorea n. superord. and three new families are erected for its recent members: Anonchohapteridae n. fam., Acolpentronidae n. fam. and Anacanthoridae n. fam. (with 7 + 7, 8 + 8 and 9 + 9 unhinged marginal hooks, respectively). Except for the families of Articulonchoinea (e.g. Acanthocotylidae, Gyrodactylidae, Tetraonchoididae) Bychowsky's (1957) division of the Monogenea into the Oligonchoinea and Polyonchoinea fits the proposed scheme, i.e. monogeneans with unhinged marginal hooks form one old group, the Oligonchoinea, which have 5 + 5 unhinged marginal hooks, and the other group form the Polyonchoinea, which (with the exception of the Hexabothriidae) has a greater number (7 + 7, 8 + 8 or 9 + 9) of unhinged marginal hooks. It is proposed that both these names, Oligonchoinea (sensu mihi) and Polyonchoinea (sensu mihi), will be retained on one side and Articulonchoinea placed on the other side, which reflects the early monogenean evolution. Except for the members of Ananchorea [Polyonchoinea], all members of the Oligonchoinea and Polyonchoinea have anchors, which imply that they are further evolved, i.e. have passed the 5 + 5 marginal hook evolutionary capacity level (Malmberg, 1986). There are two main types of anchors in the Monogenea: haptoral anchors, with anlages appearing in the haptor, and peduncular anchors, with anlages in the peduncle. There are two types of haptoral anchors: peripheral haptoral anchors, ontogenetically the oldest, and central haptoral anchors. Peduncular anchors, in turn, are ontogenetically younger than peripheral haptoral anchors. There may be two pairs of peduncular anchors: medial peduncular anchors, ontogentically the oldest, and lateral peduncular anchors. Only peduncular (not haptoral) anchors have anchor bars. Monogeneans with haptoral anchors are here called Mediohaptanchorea n. superord. and Laterohaptanchorea n. superord. or haptanchoreans. All oligonchoineans and the oldest polyonchoineans are haptanchoreans. Certain members of Calceostomatidae [Polyonchoinea] are the only monogeneans with both (peripheral) haptoral and peduncular anchors (one pair). These monogeneans are here called Mixanchorea n. superord. Polyonchoineans with peduncular anchors and unhinged marginal hooks are here called the Pedunculanchorea n. superord. The most primitive pedunculanchoreans have only one pair of peduncular anchors with an anchor bar, while the most advanced have both medial and lateral peduncular anchors; each pair having an anchor bar. Certain families of the Articulonchoinea, the Anchorea n. superord., also have peduncular anchors (parallel evolution): only one family, the Sundanonchidae n. fam., has both medial and lateral peduncular anchors, each anchor pair with an anchor bar. Evolutionary lines from different monogenean evolutionary capacity levels are discussed and a new system of classification for the Monogenea is proposed.In agreeing to publish this article, I recognise that its contents are controversial and contrary to generally accepted views on monogenean systematics and evolution. I have anticipated a reaction to the article by inviting senior workers in the field to comment upon it: their views will be reported in a future issue of this journal. EditorIn agreeing to publish this article, I recognise that its contents are controversial and contrary to generally accepted views on monogenean systematics and evolution. I have anticipated a reaction to the article by inviting senior workers in the field to comment upon it: their views will be reported in a future issue of this journal. Editor