裂殖壶藻萃取油脂工艺的对比分析

以裂殖壶藻为原料,分别以甲醇和乙醇作为携带剂,通过索氏萃取法进行萃取对比,得出最佳的携带剂,然后进行超声波萃取。结果表明:以乙醇为携带剂的萃取率更高,索氏萃取微藻粗脂的最优条件(时间8 h,温度100℃,液固比10∶1)下可得最大萃取率为30.5%;以乙醇为携带剂,超声波萃取的最优条件(时间2 h,温度40℃,液固比120∶1,超声波功率600 W)下可得最大萃取率为53.5%。从微藻粗脂萃取率的角度来看,超声波法优于索氏萃取法。     

A new and enigmatic representative of Leucocythere Kaufmann, 1892 from the Eastern Cape Province (South Africa) (Crustacea,Ostracoda)

Leucocythere helenae sp. nov. is described from a small, semi-permanent dam near Grahamstown (RSA). It belongs to Leucocythere s.s., but is at the same time characterized by a number of aberrant features, especially the shape and size of the large copulatory process on the hemipenis and the relatively short setae on the P(3) of the male. A cladistic analysis is conducted and it appears that within Leucocythere, the African species have the most plesiomorphic character states. The discovery of L. helenae sp. nov. in South Africa furthermore falsifies previous hypotheses on the age and origin of the Leucocytherini in general and Leucocythere s.s. in particular. It should now be accepted that the latter genus is not of Pleistocene age, but much older, although the lack of fossil material prevents more exact dating. Also, when the cladogram is studied in conjunction with the present day distribution map of Leucocythere, the concept of a Palaearctic origin of this genus must be rejected. The most plausible hypothesis to date on the origin of this group appears to be a generalized distribution of a leucocytherid ancestor over Europe, Asia and Africa (at least), with subsequent speciation through vicariance.     

温度、光照和磷质量浓度对小环藻、大型溞和金鱼藻共培养的影响

为了研究温度、光照和磷质量浓度对生物操纵效果的影响,选用小环藻、大型溞和金鱼藻分别作为浮游植物、浮游动物和大型水生植物的代表种,建立不同磷质量浓度(0.05、0.1、0.5、2mg/L)的水生微宇宙模型,研究不同温度梯度(15、20、25、30℃)、不同光照强度(1000、2600、4200、5800lx)及不同光暗比(10∶14、12∶12、14∶10、16∶8)条件下浮游动物和沉水植物的控藻效果.结果表明:磷质量浓度为0.05~0.5mg/L、温度在20~25℃时,大型溞和金鱼藻生长较好,对小环藻有明显的抑制作用;磷质量浓度为0.05~0.5 mg/L、光照强度在1000~4200lx时,大型溞和金鱼藻对小环藻有明显的抑制作用;强光(5800lx)有利于小环藻、金鱼藻的生长,但对大型溞有抑制;磷质量浓度为0.05~0.5mg·L-1,光暗比为14h∶10h时,大型溞和金鱼藻生长最好,可以达到很好的抑藻效果;当磷质量浓度相同时,温度30℃、光照5800lx时,培养液中氮磷去除率最高.     

Ants feeding on anal exudate from tortricid larvae: a new type of trophobiosis

A new type of trophobiosis between tortricid larvae of a hitherto unknown genus and species, and various ant species of the subfamilies Formicinae, Dolichoderinae and Myrmicinae, was found in Malaysia. The larvae live in silken shelters fixed to the leaves of bamboo. In response to mechanical stimuli from the ants, they discharge from the anus a liquid containing sugar and amino acids and/or protein. The tortricid is described as Semutophila saccharopa gen. nov., sp. nov.; a second species, S. susurra sp. nov., is described from New Guinea.     

A review of the genus Sisyrophanus Karsch 1886 (Diptera: Bombyliidae)

The Afrotropical genus Sisyrophanus Karsch is reviewed and a key is provided for the separation of the eight known species, including Sisyrophanus stylifer sp. nov. which is described from Burundi and Tanzania.     

鱼腥藻PCC7120染色体MazEF同源基因对asr0757/alr0758的初步研究

鱼腥藻PCC7120染色体上的基因对asr0757/alr0758,经NCBI比对显示其与大肠杆菌中的毒素-抗毒素基因Maz EF具有较高的同源性,且具有毒素-抗毒素系统基因的保守遗传结构,为研究其是否属于Maz EF家族系统基因,构建同时含有asr0757和alr0758基因的双启动子选择性表达载体,先选择性诱导了该基因对的表达,再验证了其表达产物对细菌生长的影响.结果显示:成功诱导表达出了目的蛋白asr0757(13.5KD)和alr0758(17.5KD),当单独诱导asr0757基因表达时,细菌生长状况不受影响,单独诱导alr0758表达时细菌生长明显受到抑制,同时诱导asr0757和alr0758基因时细菌生长恢复正常,说明asr0757/alr0758构成具有生物功能的Maz EF家族系统基因对,具有毒性与抗毒性功能.     

一株软骨霉状菌的纯化方法

从武夷山的一枯枝上分离得到了一株稀有软骨霉状菌,在培养过程中发现,该株黏细菌在人工培养基上只有在与一种未知的细菌共培养的状态下才能长出典型的子实体并保持菌种的活力.然而要从共培养的菌落中纯化这株黏细菌,使用常规的黏细菌纯化技术几乎是不可能.在这种情况下对伴生细菌进行16SrDNA菌种鉴定,再根据鉴定为施氏假单胞菌(Ps...     

Evidence of a parasite protist in Eurhomalea lenticularis (Sowerby, 1835) (Mollusca: Bivalvia): A case of intraoocytarian parasitism

In the present paper a microsporidian parasitic protist is described and characterized; it was observed in oocytes of Eurhomalea lenticularis Sowerby. The clams were obtained in Algarrobo, Chile (33°20′S, 71°40′W). The observations were made on 5?µm sections of female clam gonads, processed by routine histological techniques with ARTETA trichromic stain. According to the parasite's characteristics, it is established that the microsporidian protist is related to the genus Steinhausia (Chytridiopsidae). Microsporidian prevalence reached 20.6% (n?=?34) in summer months, but there was no evidences of cell damage in the oocyte of the host; in a total of 66 female clams, a 10.6% of infection was detected between December 1995 and August 1996. The infection intensity showed that 77.4% of the infested acini had single parasitized oocytes, and 88.0% of total oocytes parasitized contained only one cyst in the cytoplasm.     

Two new species of the genus Sinella Brook, 1882 (Collembola: Entomobryidae) from East China

Two new species, Sinella hexaseta sp. nov. and Sinella pauciseta sp. nov., collected from East China, Anhui and Zhejiang provinces, respectively, were described. Both are easily discriminated from each other and all known Sinella species by their unique dorsocentral chaetotaxic patterns on Abd. IV. In S. pauciseta sp. nov., postlabial setae H_1–4 are ciliate, which are smooth in all other known species of the genus.