<Emphasis Type="Italic">Halobacillus naozhouensis</Emphasis> sp. nov., a moderately halophilic bacterium isolated from a sea anemone

A moderately halophilic, Gram-positive, catalase- and oxidase-positive, rod-shaped, aerobic bacterium, designated strain JSM 071068^T, was isolated from a sea anemone (Anthopleura xanthogrammica) collected from the Naozhou Island on the Leizhou Bay in the South China Sea. Cells were motile by means of peritrichous flagella and formed ellipsoidal endospores lying in subterminal swollen sporangia. Strain JSM 071068^T was able to grow with 1–20% (w/v) total salts (optimum, 6–9%), at pH values of 6.0–10.0 (optimum, pH 7.5) and a temperature range of 10–35°C (optimum, 25°C). meso-Diaminopimelic acid was present in the cell-wall peptidoglycan. The predominant menaquinone was MK-7 and the major cellular fatty acids were anteiso-C_15:0, anteiso-C_17:0 and iso-C_15:0. The genomic DNA G + C content was 42.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that strain JSM 071068^T belonged to the genus Halobacillus. The 16S rRNA gene sequence similarities between strain JSM 071068^T and the type strains of the recognized Halobacillus species ranged from 97.9% (with Halobacillus alkaliphilus) to 95.3% (with Halobacillus kuroshimensis). The levels of DNA–DNA relatedness between the new isolate and the type strains of H. alkaliphilus, Halobacillus campisalis, Halobacillus halophilus and Halobacillus seohaensis were 25.6, 22.1, 10.8 and 13.2%, respectively. The combination of phylogenetic analysis, DNA–DNA relatedness, phenotypic characteristics and chemotaxonomic data supported the view that strain JSM 071068^T represents a new species of the genus Halobacillus, for which the name Halobacillus naozhouensis sp. nov. is proposed, with JSM 071068^T (=DSM 21183^T =KCTC 13234^T) as the type strain. The GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of strain JSM 071068^T is EU925615.     

Development of a direct competitive enzyme-linked immunosorbent assay for parathion residue in food samples

A heterologous direct competitive enzyme-linked immunosorbent assay (ELISA) for parathion residue determination is described based on a monoclonal antibody and a new competitor. The effects of several physicochemical factors, such as methanol concentration, ionic strength, pH value, and sample matrix, on the performance of the ELISA were optimized for the sake of obtaining a satisfactory assay sensitivity. Results showed that when the assay medium was in the optimized condition (phosphate buffer solution [PBS] containing 10% [v/v] methanol and 0.2 mol/L NaCl at a pH value of 5.0), the sensitivity (estimated as the IC₅₀ value) and the limit of detection (LOD, estimated as the IC₁₀ value) were 1.19 and 0.08 ng/ml, respectively. The precision investigation indicated that the intraassay precision values all were below 10% and that the interassay precision values ranged from 4.89 to 19.12%. In addition, the developed ELISA showed a good linear correlation (r² = 0.9962) to gas chromatography within the analyte’s concentration range of 0.1 to 16 ng/ml. When applied to the fortified samples (parathion adding level: 5-15 μg/kg), the developed ELISA presented mean recoveries of 127.46, 122.52, 91.92, 124.01, 129.72, 99.37, and 87.17% for tomato, cucumber, banana, apple, orange, pear, and sugarcane, respectively. Results indicated that the established ELISA is a potential tool for parathion residue determination.     

Sox2基因3'非翻译区保守元件对基因表达的调控作用

转录因子Sox2是脊椎动物早期发育中最早表达的神经系统特异性基因之一,同时在干细胞的维持中也起着关键作用。通过生物信息学分析,作者发现在脊椎动物Sox2 mRNA 3'非翻译区中存在4段非常保守的富含AU的区域。将这些片段按照不同的组合克隆到GFP和荧光素酶两种报告基因载体中,在非洲爪蟾胚胎和培养细胞中检测了这些片段对报告基因表达的影响。结果显示,Sox2的3'UTR可影响报告基因的表达水平,特别是其中的保守片段2可显著提高报告基因的表达水平,表明Sox2 3'非翻译区有可能参与Sox2表达的转录后调控。     

snthr-1Bao稀毛小鼠突变基因的精确定位及克隆鉴定

snthr-1Bao稀毛小鼠足本实验室培育的呈单基因隐性遗传的突变系小鼠,突变基因已被初步定位于第9号染色体末端;为了精确定位并鉴定snthr-1Bao稀毛小鼠的突变基因,将(C57BL/6Jxsnthr-1Bao)F1代互交繁殖F2代小鼠4400余只,其中稀毛小鼠1100只,并在2个微卫星、35个可能的简单序列重复标记(simple sequence repeat,SSR)及3个酶切扩增多态性序列(cleaved amplified polymorphic sequences,CAPS)标记中找到4个合适的基因组标记.利用这些标记及F2代稀毛小鼠将突变基因精确定位到第9号染色体距着丝粒117.763 kb及119.129kb之间1.367Mb的范用内,在其问的21个基因中确定Plcdl为稀毛突变的强力候选基因.通过对基因组的直接测序,发现snthr-1Bao稀毛小鼠基因组上有一个14883bp的缺失,这一缺失包含了Plcd1基因的4-15号外显子及Vill基因的10-19号外显子.推测极可能是Plcdl基因缺失导致snthr-1Bao小鼠出现稀毛表型.     

低温污水中耐冷微生物的筛选及多样性分析

采用4种分离培养基对新疆乌鲁木齐市污水处理厂低温污水中的耐冷微生物进行分离筛选, 共获得各种耐冷微生物154株, 其中丝状真菌12株, 酵母46株, 放线菌6株, 细菌90株。并对部分菌株的耐受性和产酶特性进行了研究, 获得了耐4%NaCl的菌株44株, 耐0.2%苯酚的16株, 耐0.5% SDS的33株, 具有淀粉酶活性的菌株40株, 蛋白酶活性的30株, 脂酶活性的27株。对其中60株细菌进行16S rRNA基因测序, 序列比对分析表明, 其分属13个属, 其中菌株39与不动杆菌属中的标准菌株Aci     

小叶黄杨化学成分的研究

小叶黄杨氯仿组分通过硅胶柱色谱分离纯化,从中分离得到9个化合物,分别鉴定为:β-谷甾醇(β-Sitosterol,Ⅰ)、豆甾醇(Stigmasterol,Ⅱ)、胡萝卜甙(daucosterol,Ⅲ)、水杨酸(salicylis acid,Ⅳ)、香草酸(vanillicacid,Ⅴ)、5,4′-二羟基-3,3′,7-三甲氧基-黄酮(5,4′-dihydroxy-3,3′,7-trimethoxy-flavone,Ⅵ)、5,4′-二羟基-3,3′,6,7-四甲氧基-黄酮(5,4′-dihydroxy-3,3′,6,7-tetramethoxy-flavone,Ⅶ)、Cleomiscosin A(Ⅷ)、3,5-二羟基-4′,6,7-三甲氧基-黄酮-3′-O-β-D-葡萄糖甙(3,5-dihydroxl-4′,6,7-trimethoxyl-flavone-3′-O-β-D-glucopyranoside,Ⅸ),其中化合物Ⅳ、Ⅴ、Ⅵ、Ⅶ均首次从该属植物中分离得到。     

产河豚毒素(TTX)菌株ZY-23的分离与鉴定

从河豚卵巢中分离得到35株细菌,利用小鼠生物法检测获11株产河豚毒素(TTX)菌株,其中有6株菌产TTX含量达400ng/mL以上,对其中ZY-23菌株进行传统分类学方法鉴定,初步鉴定为液化沙雷氏菌(Serratia liquefaciens)。16SrRNA基因序列分析,ZY-23菌株与Serratiasp.Tp5的亲缘关系最近,相似度达99%。用荧光检测分析其发酵液,发现在423nm处与标准品具有相同的发射峰,初步证实发酵液含有TTX。     

Zhihengliuella salsuginis sp. nov., a moderately halophilic actinobacterium from a subterranean brine

A novel moderately halophilic, alkaliphilic, non-motile, non-sporulating, catalase-positive, oxidase-negative, aerobic, coccus-shaped, Gram-positive bacterium, designated strain JSM 071043^T, was isolated from a subterranean brine sample collected from a salt mine in Hunan Province, China. Growth occurred with 0.5–20% (w/v) NaCl (optimum 5–10%) at pH 6.5–10.5 (optimum pH 8.5) and at 10–40°C (optimum 25–30°C). Good growth also occurred in the presence of 0.5–20% (w/v) KCl (optimum 5–8%) or 0.5–25% (w/v) MgCl₂·6H₂O (optimum 5–10%). The peptidoglycan type was A4α (l-Lys–l-Ala–l-Glu) and major cell-wall sugars were tyvelose and mannose. The major cellular fatty acids were anteiso-C_15:0, iso-C_16:0 and anteiso-C_17:0. Strain JSM 071043^T contained MK-9 and MK-8 as the predominant menaquinones and diphosphatidylglycerol, phosphatidylglycerol and phosphatidylinositol as the major polar lipids. The DNA G + C content was 67.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain JSM 071043^T was a member of the suborder Micrococcineae, and was most closely related to Zhihengliuella halotolerans YIM 70185^T (sequence similarity 98.9%) and Zhihengliuella alba YIM 90734^T (98.2%), and the three strains formed a distinct branch in the phylogenetic tree. The combination of phylogenetic analysis, DNA–DNA relatedness values, phenotypic characteristics and chemotaxonomic data supports the proposal that strain JSM 071043^T represents a novel species of the genus Zhihengliuella, for which the name Z. salsuginis sp. nov. is proposed. The type strain is JSM 071043^T (= DSM 21149^T = KCTC 19466^T).     

家蝇蛹凝集素的免疫调节作用

本实验研究了从家蝇蛹体内分离的一种凝集素,研究了其免疫调节的性质。首先将收集的家蝇蛹在缓冲液中研磨,得到粗提物,经过亲和吸附、竞争洗脱等步骤得到了纯品。电泳结果表明家蝇蛹凝集素分子量大约为55kD。通过检测巨噬细胞分泌的细胞因子IL-6、IL-12等实验,证明了家蝇蛹凝集素浓度在5μg/mL时对与巨噬细胞分泌IL-6有显著增强作用,家蝇蛹凝集素的浓度在10μg/mL时对巨噬细胞分泌IL-12有显著效果。通过小鼠脾淋巴细胞增殖试验结果可知家蝇蛹凝集素对于混合淋巴细胞增殖有促进作用。以上试验结果说明家蝇蛹凝集素免疫调节作用,为天然免疫增强剂的开发提供了一定的参考依据。     

地被菊的再生与转化系统的建立

文章初步建立了地被菊品种‘早小春’组织培养植株再生系统和农杆菌介导的稳定转化系统。幼蕾管状花瓣诱导培养获得再生植株的最适培养基为MS+2.0mg·L-1ZT+0.5mg·L-12,4-D,愈伤组织诱导率可达95%以上,不定芽的分化率达到87%以上。以再生植株叶片为外植体进行遗传转化实验的结果表明:用MS液体培养基稀释的农杆菌液效果最佳,以感染8min左右,共培养3d为宜。同时附加40mg·L-1卡那霉素和500mg·L-1头孢霉素是地被菊转化的最佳条件。