科学术语的翻译实践及其概念的语境重置——从“bacterium”到“细菌”

19世纪末20世纪初,“bacterium”概念由西方传播至我国,并最终以“细菌”二字成为汉语词。这是一则外来概念在华传播的成功案例。“细菌”的入华“旅行”先后经历了术语“bacterium”的翻译实践、概念“bacterium”的在华接受及译词“细菌”的最终确立。“微虫”“微生物”“微菌”“霉菌”“微生毒”“微生虫”“璧他利亚”等译词的涌现、共存与淘汰体现了概念跨文化传播在语言层面的复杂表征,语境重置则是此番过程的本质。汉语语境“虫”概念和本土传统的病因学体系为“旅行”概念的接受创造条件。“细菌”二字被确立为术语“bacterium”的译词则是社会权力制约下的结果。深入挖掘这则成功案例,厘清概念跨文化传输的特点,或能为提升概念跨文化传播效率提供些许启示。

Bio-inhibitive effect of an algal symbiotic bacterium on corrosion of magnesium in marine environment

It is a longstanding and challenging task to develop sustainable environment-friendly and cost-effective corrosion-protection technologies for Mg alloys, especially under marine conditions in which corrosion can normally be significantly accelerated by bacterial activity. However,this paper reports on the corrosion of highly active Mg interestingly inhibited by an algal-symbiotic bacterium Bacillus altitudinis. The corrosion of Mg in the presence of the bacterium drastically reduced by one order of magnitude after 14 days of immersion. This means that the algal-symbiotic bacterium widely available in natural ocean environments may be employed as a green and sustainable inhibitor in the marine industry. Based on electrochemical measurements, surface analyses and microbe experiments, a combined inhibition mechanism is proposed in the paper to interpret the interesting corrosion behavior of Mg.

高效产氢细菌新种——Ethanologenbacterium sp.X-1的分离鉴定及其产氢效能

为获得高效产氢发酵细菌 ,采用改进的厌氧Hungate培养技术 ,从生物制氢反应器CSTR中分离一株产氢细菌X 1。对该株细菌进行了形态学特征、生理生化指标、16SrDNA和 16S 2 3SrDNA间隔区序列分析等研究。结果表明与最相近的种属Clostridiumcellulosi和Acetanaerobacteriumelongatum等的 16SrRNA基因序列同源性为 94 %以下。16S 2 3SrRNA间隔区基因序列比对分析显示保守区域仅为tRNAAla和tRNAIle序列 ,其它可变部位没有同源性区域 ,鉴定为新属Ethanologenbacteriumsp .。该株细菌为专性厌氧杆菌 ,代谢特征为乙醇发酵 ,葡萄糖发酵产物主要为乙醇、乙酸、H2 和CO2 。在pH4 0和 36℃条件下最大产氢速率是 2 8 3mmolH2 (gdrycell·h)。

厌氧细菌Acetanaerobacterium elongatum从葡萄糖的产氢特性研究

为了了解影响厌氧发酵产氢细菌Acetanaerobacterium elongatumZ7产氢效率的因素,采用生理学方法对其进行了研究。结果表明:乙醇型发酵菌A.elongatumZ7的最适产氢温度为37℃,最适产氢的起始pH为8.0。该菌发酵葡萄糖和阿拉伯糖产氢的能力较强,氢气产率分别为1.55mol H2/mol葡萄糖和1.50mol H2/mol阿拉伯糖。酵母粉是菌株Z7生长和产氢所必须的生长因子;pH影响菌株的生长和葡萄糖利用率;氢压则影响电子流的分配,从而改变代谢产物乙酸和乙醇的比例;当产氢菌与甲烷菌共培养以维持发酵体系低的氢压时,可使氢的理论产量提高约4倍;培养基中乙酸钠浓度>60mmol/L明显抑制产氢。另外,一个只利用蛋白类物质的细菌能够促进菌株Z7对葡萄糖的利用,进而提供氢产量,为生物制氢的工业化生产提供理论参考。

Isolation of a Bacterium Strain Degraded Agar

One in 58 strains of bacteria isolated from the compost showed clear colonies after a few days of growth on the plates containing medium made of only agar and water.Water suspension contained only agar (2 and 8g·L -1 ) with two controls (normal saline,LB medium) was inoculated with the bacterium BR5-1 to see whether there was an increasement of the alive bacteria concentration after 48 h of the growth.The results showed that there was a significant rising of the alive bacteria concentration in the agar susp...

来源于P.bacterium 1109的甘露醇脱氢酶的重组纯化及酶学性质研究

本文将来自P.bacterium 1109的甘露糖醇脱氢酶(MDH)表达并提取纯化,研究了该重组酶的酶学性质及其在甘露醇生产中的工艺条件。结果显示重组MDH是一个相对分子量为37 kDa的四聚体。氨基酸序列比对发现其与大多数MDHs的同源性小于40%。该酶的最适pH和温度分别为8.5和80℃,且当金属离子Zn^(2+)存在时,重组MDH的活力提高到对照组的260%。此外,重组MDH在75℃孵育6 h后仍可保留超过85%的残留活性,热稳定性较高,比大多数MDHs的活性高。底物特异性研究表明其对D-果糖具有较高的专一性。重组MDH催化D-果糖的米氏常数(K_m)和催化效率(k_(cat)/K_m)分别为20 mmol/L和7.5 L/(mmol·min)。重组MDH在以400 mmol/L的D-果糖为底物的反应系统中,可将80%以上的D-果糖转化为甘露糖醇。通过对反应条件的优化,为后续工业化生产制备甘露醇奠定了基础。

Effect of Sulfate Reduced Bacterium on Corrosion Behavior of 10CrMoAl Steel

The effects of sulfate reduced bacterium （SRB） on the corrosion behavior of 10CrMoAl steel in seawater were studied by chemical immersion, potentiodynamic polarization, electrochemical impedance spectroscopy measurement, and scanning electron microscope techniques. The results show that the content of element sulfur in the corrosion product of 10CrMoAl steel in seawater with SRB is up to 9. 23 %, which is higher than that of the same in sterile seawater. X-ray diffraction demonstrates that the main corrosion product is FeS. SRB increases the corrosion rate by anodic depolarization of the metabolized sulfide product. SEM observation indicates that the corrosion product is not distributed continuously; in addition, bacilliform sulfate-reduced bacterium accumulates on the local surface of 10CrMoAl steel. Hence, SRB enhances sensitivity to the localized corrosion of 10CrMoAl steel in seawater.

Purification and Characterization of 2-Haloacid Dehalogenase from Marine Bacterium Paracoccus sp. DEH99, Isolated from Marine Sponge Hymeniacidon perlevis

2-haloacid dehalogenases constitute a group of dehalogenases which are capable of dehalogenating the halogenated organic compounds. So far, the 2-haloacid dehalogenases have been found in many bacteria, but not in Paracoccus genus. In the present study, one enzyme 2-haloacid dehalogenase(designated as Deh99), induced by DL-2-chloropropionate(DL-2-CPA), was purified from the marine bacterium Paracoccus sp. DEH99, isolated from marine sponge Hymeniacidon perlevis. The enzyme of Deh99 was purified to homogeneity by ammonium sulfate precipitation, ion exchange chromatography(Q-Sepharose HP), and Superdex 200 gel filtration chromatography. The molecular weight of Deh99 was estimated to be 25.0 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE), and 50.0 kDa natively by gel filtration chromatography. The enzyme of Deh99 stereospecifically dehalogenated L-2-CPA to produce D-lactate, with an apparent Michaelis-Menten constant(Km) value of 0.21 mmol L-1 for L-2-CPA. The optimal pH and temperature for Deh99 activity were 10.0 and 40℃, respectively. The enzyme of Deh99 acted on short-carbon-chain 2-haloacids, with the highest activity towards monochloroacetate. The activity of Deh99 was slightly affected by DTT and EDTA, but strongly inhibited by Cu2+ and Zn2+. The enzyme of Deh99 shows unique substrate specificity and inhibitor sensitivities compared to previously characterized 2-haloacid dehalogenases and is the reported one about purified 2-haloacid dehalogenase isolated from the bacteria of Paracoccus genus.

Isolation and characteristics of one marine psychrotrophic cellulase-generating bacterium Ar/w/b/75°/10/5 from Chuckchi Sea,Arctic

Microorganisms living in polar zones play an important part as the potential source of organic activity materials with low temperature characteristics in the bio-technological applications. A psychrotrophic bacterium (strain Ar/w/b/75°/10/5) , producing cellulose at low temperatures during late-exponential and early-stationary phases of cell growth, was isolated from sea ice-covered surface water in Chuckchi Sea, Arctic. This bacterium, with rod cells, was Gram-negative, slightly halophilic. Colony growing on agar plate was in black. Optimum growth temperature was 15℃. No cell growth was observed at 351 or above. Optimum salt concentration for cell growth was between 2 and 3 % of sodium chloride in media. Maximal cellulase activity was detected at a temperature of 35℃ and pH8. Cellulase was irreversibly inactivated when incubated at 55℃ within 30 min. Enzyme can be kept stable at the temperature no higher than 25℃. Of special interest was that this bacterium produced various extracellular enzymes including cellulase, amylase, agar hydrolase and protease, at low or moderate temperature conditions, which is certainly of it potential value for applications.

Extraction and physicochemical characteristics of a red pigment produced by marine bacterium strain S - 9801

A red pigment that has better biological properties is produced by marine bacterium strainS- 9801. The extraction methods, physicochemical and toxicity of the pigment have been studied. Dissolubility of pigment in the five organic solvent has been tested, and ethanol is optimally chosen for extraction. Physicochemical characteristics of this pigment was stable. The absorbance of the pigment solution was no losing when put under natural light for 10 days or treated by UV for 30 minutes, color of the pigment unchanged after 100℃ hythere for 1 h or 80 ℃ xerother for 2 h. The median lethal dose (LD_50) of the rat by celiac injection was 670.04 mg/kg and minimum lethal dose of oral was greater than 2 000 mg/kg.

Inhibition of spore germination of Ulva pertusa by the marine bacterium Pseudoalteromonas haloplanktis CI4

The effect of the bacterial strain C14 on the germination of spores from the green alga Ulva pertusa was assayed and it was found that the bacterial biofilm and cell-free supernatant strongly inhibited spore germination. In attempts to define the chemical nature of she antifouling substance in the supernatant of C14, the culture supernatants were tested for activity after heat treatment, enzymatic treatments, size fractionation, and separation into aqueous and organic fractions. Results suggest that this bacterium produces an extracellular component with specific activity toward algal spores that was heat-sensitive and between 3 and 10 kDa in molecular size. The exposure of the organic phase fraction to spores showed inhibitive effect on spore germination. Pronase and carboxypeptidase y did not significantly affect the activity of inhibitory component, suggesting that the component was not a protein or a peptide. The bacterium C14 was identified as Pseudoalteromonas haloplanktis based on the phenotypic characters and 16S rRNA gene analvsis.

Degradation of 2,6-di-tert-butylphenol by an isolated high-efficiency bacterium strain

An aerobic bacterium strain, F-3-4, capable of effectively degrading 2,6-di-tert-butylphenol(2,6-DTBP), was isolated and screened out from an acrylic fiber wastewater and the biofilm in the wastewater treatment facilities. This strain was identified as Alcaligenes sp. through morphological, physiological and biochemical examinations. After cultivation, the strain was enhanced by 26.3% in its degradation capacity for 2,6-DTBP. Results indicated that the strain was able to utilize 2,6-DTBP, lysine, lactamine, citrate, n-utenedioic acid and malic acid as the sole carbon and energy source, alkalinize acetamide, asparagine, L-histidine, acetate, citrate and propionate, but failed to utilize glucose, D-fructose, D-seminose, D-xylose, serine and phenylalanine as the sole carbon and energy source. The optimal growth conditions were determined to be: temperature 37℃, pH 7.0, inoculum size 0.1% and shaker rotary speed 250 r/min. Under the optimal conditions, the degradation kinetics of 2,6-DTBP with an initial concentration of 100 mg/L was studied. Results indicated that 62.4% of 2,6-DTBP was removed after 11 d. The degradation kinetics could be expressed by Eckenfelder equation with a half life of 9.38 d. In addition, the initial concentration of 2,6-DTBP played an important role on the degradation ability of the strain. The maximum initial concentration of 2,6-DTBP was determined to be 200 mg/L. Above this level, the strain was overloaded and exhibited significant inhibition.

Isolation and characterization of a marine bacterium producing protease from Chukchi Sea, Arctic

A Gram negative bacterium Ar/W/b/75°25′N/1 producing extracellular alkaline protease was isolated from surface water of latitude 75°25′N, and longitude 162°25′W in Chukchi sea, Arctic. The strain can grow at the temperature range from 7℃ to 30℃, and grow better at 30℃. It can not grow at 40℃. Keeping certain salinity concentration in medium is necessary for cell growth. It grows well in medium containing salinity concentration from 0.5% to 10% sodium chloride. Glucose, sucrose and soluble starch can be utilized by the strain, among which glucose is the optimal carbon source. Peptone is the optimal organic nitrogen source for cell growth and protease producing, and ammonium nitrate is the optimal inorganic nitrogen source. About 75 7% of total protease of the strain are extracellular enzyme. Optimal temperature for proteolytic activity is at 40℃. Protease of the strain keeps stable below 40℃, and shows high proteolytic activity within the pH range from 7 to 11.

Characteristics of intracellular polyphosphate granules and phosphorus-absorption of a marine polyphosphateaccumulating bacterium, Halomonas sp. YSR-3

Halomonas sp.YSR-3 was isolated from the Yellow Sea and identified as a polyphosphate-accumulating bacterium and the characteristics of its intracellular polyphosphate(polyP)granules and phosphorus absorption were studied.Most YSR-3 cells stored one or two polyP granules in regular appearance and high-density.The diameter of the granules was about 400 nm measuring by a transmission electron microscope(TEM).After stained with 4,6-diamidino-2-phenylindole(DAPI)and visualized by a fluorescence microscope,the cells turned blue and the granules were bright yellow.The composition of granules includes P(major ingredient),Mg,S,K,and Ca as detected by an energy dispersive X-ray spectrometer(EDS).When inorganic phosphorus(po34-)and ferric ion(Fe3+)were added into media,the biomass increased and the cells formed intracellular polyP granules owing to the phosphorus assimilation from media.The YSR-3 obtained higher biomass by adding 0.02 g/L FePO4 than 0.005 g/L and 0.01 g/L FePO4;however,the phosphorus absorption was higher with 0.01 g/L FePO4 than 0.005 g/L and 0.02 g/L FePO4.The optical density at wavelength 480 nm(OD480nm)was 0.79 and 100%cells could form intracellular polyP granules.These results show that strain YSR-3 is able to acquire higher biomass and absorb more inorganic phosphorus when 0.01 g/L FePO4 is added.The characteristics of absorbing and storing phosphorus as intracellular inorganic polyP granules have a potential for application in high-efficiency phosphorus removal in wastewater treatment.

Application of purple nonsulphur bacterium Rhodopseudomonas sp．in spat rearing of Bay Scallop Argopecten irradians irradians

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Biosurfactant-producing Ability of Highly Efficient Petroleum-degrading Bacterium BS-8

After incubation for 6 -30 h, with the rapid increase of bacterial cell number, surface tension of bacterium BS-8 was reduced sharply from 63.2 mN/m to 39.4 mN/m. The production of biosurfactants by BS-8 was growth-dependent. Using glucose as the carbon source, bacterium BS-8 was incubated. Based on centrifugation, precipitation and chromogenie reaction of the culture solution, results indicated that the biosurfactants belonged to lipopeptides. The yield of biosurfaetants isolated and purified from the culture solution was 0.58 g/L, and the critical micelle concentration （CMC） was 90 mg,/L. Under conditions of pH 4 -9, tem- perature 20 -70 ℃, NaCl concentration 1% -6%, biosurfactants predueed by BS-8 exhibited the highest stability.

Effects of Crop Rotation and Microbial Fertilizer on Nutrient Absorption and Beneficial Bacterium Abundance in Rhizosphere of Continuous Cropped Eggplant

Rotation is a method to effectively regulate the soil microbial community structure and alleviate the obstacles of continuous planting of eggplant in facilities.High-throughput sequencing technology was used to study the change of beneficial bacteria diversity and structure at the first fruit stage of continuous eggplant rhizosphere soil affected by rotation combined with Bacillus subtilis fertilizer.The result showed that beneficial bacteria in the rhizosphere soil samples of eggplant at the phylum classification level included Actinobacteria,Chloroflexi,Acidobacteria,Planctomycetes and Cyanobacteria.At the level of genus classification,the beneficial bacteria in the rhizosphere soil samples of eggplant were Bacillus,Arthrobacter,Sphingomonas and Streptomyces.The significantly differences were observed in the abundance of soil dominant bacteria and beneficial bacteria at phylum level and genus classification among different treatments.At the phylum level,compared with CK treatment,the relative abundances of Acidobacteria and Proteobacteria in BB treatment were increased by 34.4%and 20.2%,respectively.At the level of genus classification,the beneficial bacterial Arthrobacter abundance in BB treatment was 1.44 times than that of CK treatment and was significantly higher than that in CF treatment.Moreover,the total uptake of N,P and K by eggplants in BB treatment and BFN treatment were 1.68 and 1.35 times than those of CK treatment,respectively.The above results showed that the combined treatment of microbial fertilizer and rotation could increased the soil bacterial community diversity and the abundance of beneficial bacteria in the first fruit stage of eggplant,which indeed enhanced the absorption of N,P and K by continuous eggplant plants,thereby alleviating the obstacles of continuous cropping of eggplant.

Pathogenic bacterium Vibrio harveyi: an endosymbiont in the marine parasitic ciliate protozoan Cryptocaryon irritans

Vibrio harveyi, known as a pathogenic bacterium caused severe secondary bacterial infections of the large yellow croaker Larimichthys crocea, was identified as an endosymbiont in the marine parasitic ciliate protozoan Cryptocaryon irritans. Meta 16 S sequencing method was used to identify the bacterial flora in C. irritans, and V.harveyi was isolated via culture-dependent method. Vibrio harveyi was observed in cytoplasm of C. irritans at the stage of tomont both by transmission electron microscopy and by Fluorescence in situ hybridization; no signal,however, was detected in nucleus area. The relationship between V. harveyi and C. irritans and the role of endosymbiotic V. harveyi in C. irritans merit further investigation.

Biological control of rice disease and insect by chitinase-producing bacterium X2-23

Enriched by the-medium containingchitin and cell wall of Phizoctoniasolani AG-1,a bacterium X2-23 withhigher chitinase activity was isolatedfrom 166 chitinase-producing bacteria.It could distinctly inhibit the fungi

Isolation and Characterization of Bacterium isolated from Bantala Tannery Solid Wastes

Leather industries that uses the conventional chrome tanning process are subjected to high risk of contamination due to the emission of toxic Cr(VI)that poses a serious threat to the environment and human’s wellbeing.The present study were made to isolate and characterize chromium tolerant bacteria in the samples collected from four different plots of Bantala Tannery,Kolkata,West Bengal,India.Pure chromium tolerant bacterial strains were isolated from the tannery sludge samples and their relative MIC(Minimum Inhibitory Concentration)were recorded at different concentrations of Cr(VI)salts to select the highest chromium tolerant bacterium.The selected bacterium was further taken for their growth studies followed by different cultural,morphological and molecular analysis(16S rDNA).The bacterial strain was further studied through SEM(Scanning Electron microscopy)and EDX(Energy Dispersive X-ray)spectroscopy which revealed that TW4 was a gram positive,rod shaped,endospore forming,pleomorphic bacterium with phylogenetic similarities with Isoptericola sp.and genebank accession number SUB1732465 TW4 KX640927.