鱼虱Caligus seriolae形态结构的电镜观察

通过时寄生于石斑鱼鳃部的鱼虱的扫描电镜观察，作者对鱼虱的感觉器官、摄食器官和部分游泳足的结构进行描述．并对口器结构与摄食方式的关系、微细结构在分类中的作用、以及体表及部分附肢的附生毛的形态特点进行讨论．     

Influence of medium components on elastase production using crude sources by<Emphasis Type="Italic">Bacillus</Emphasis> sp. EL31410

A newly isolated strain EL31410, producing elastase (E. C3. 4. 4. 7) with high elastolytic activity was identified asBacillus sp. In the medium optimization, it was found that wheat bran and soybean flour hydrosate were the best crude carbon and nitrogen source for enzyme production, respectively. Addition of corn steep flour can affect the bacterium growth and elastase production. A fractional factorial design was applied to study the main factors that affect the enzyme production, and central composite experimental design and response surface methodology were adopted to derive a statistical model for the effect of wheat bran and soybean flour hydrosate on elastase production. The experimental results showed that wheat bran had positive effect but soybean flour hydrosate had negative effect, on enzyme production. An initial concentration of 3.4% (w/v) wheat bran and 9.4% (v/v) soybean flour hydrosate were found to be optimal for enzyme production in batch culture. The time course of elastase production in the optimized medium composition was also described. Project (No. 300024) supported by the Zhejiang Provincial Natural Science Foundation of China     

Characterization of a bioflocculant from a newly isolated Vagococcus sp. W31

INTRODUCTION Bioflocculation is a dynamic process resulting from the synthesis of extracellular polymer by living cells. Since flocculation in microbial system was first reported by Louis Pasteur (Salehizadeh and Sho-jaosadati, 2001), bioflocculation has been investi-gated extensively and a correlation was established between the accumulation of extracellular biofloccu-lants and cell aggregation (Tenney and Verhoff, 1973). Bioflocculants are essentially polymers pro-duced by microorgan…     

钙镁电气石检测特征探析

在宝石检测中发现，钙镁电气石呈黄绿色，与祖母绿相似。利用折射仪、红外光谱仪等手段测试确定为电气石。采用X射线衍射和电子探针分析（Cr2O含量仅0．08％），结果定名为钙镁电气石。它的主要鉴定特征与不同变种的电气石近似，与其它相似宝石的特性特征区别明显。     

营养和寄生性膜翅目的性分化 3.移植平腹小蜂卵后的性比变化

寄主卵大小及新鲜陈旧会影响平腹小蜂的性比本试验用移植卵的方法，证实了影响该蜂性比的关键在于：靠平腹小蜂产卵瓣上的感觉器感知寄主卵的大小及新鲜程度，通过神经肌肉控制受精囊是否释放精子入卵，决定产下的是受精卵或非受精卵，因而影响子代蜂的性比．     

Improved elastase production by Bacillus sp. EL31410─further optimization and kinetics studies of culture medium for batch fermentation

INTRODUCTION Elastase is an enzyme that attacks and solubi-lizes elastin. As elastase can degrade elastin (Mori-hara, 1967) that other proteases cannot; it has broad applications in medical therapy, food processing and daily use chemicals industry. Considerable eff- orts were made to screen the elastase-producing strains, to study its pathogen effect and its charac-terizations (Tsuzuki and Oka, 1965; Tsai et al., 1988; Sharon et al., 1997; Ozaki and Shiio, 1975). Shiio, 1975). Reporte…     

Effect of temperature on batch elastase production by Bacillus sp. EL31410

The production of elastase by Bacillus sp. EL31410 at various temperatures was investigated. In order to study the effect of temperature on elastase fermentation, different cultivation temperatures, ranging from 39 ℃ to 28 ℃, were evaluated in shake flask. The result indicated that 37 ℃ was best for cell growth at earlier stage; while maximum elastase activity was obtained when the cells were cultivated at 30 ℃. This result was verified by batch fermentation in 5-L bio-reactor under 37 ℃ and 30 ℃ temperature, respectively. The specific cell growth rate at 37 ℃ was higher than that at 30 ℃ during earlier stage of cultivation. The maximum value [5.5 U/(h-g DCW)] of elastase formation rate occurred at 24 h at 30 ℃ compared to 4.6 U/(h-g DCW) at 30 h at 37 ℃. Based on these results, two-stage temperature shift strategy and oscillatory temperature cultivation mode were evaluated in the next study. When compared to single temperature of 37 ℃ or 30 ℃, both two-stage temperature shift strategy and os     

云南牛蛭部分基因注释及功能分类

以南美水蛭抗凝血Xa因子mRNA为模板设计引物,利用RT-PCR随机克隆云南牛蛭（P.yunnanensis.sp.nov）相关基因,结果得到多条片段,经严格筛选和鉴定后,确定大于200 bp ESTs序列,通过对这些ESTs序列进行聚类、拼接,结果得到10条片段,Genebank注册号分别为HQ285410,HQ285411,HQ285412,HQ285413,HQ285414,HQ285415,HQ285416,HQ285417,HQ285418,HQ285419.以上获得的云南水蛭头部和身体细胞部分转录的ESTs片段均与南美水蛭有较大差异,表明云南水蛭与南美水蛭可能使用完全不同的抗凝血机制.     

桑树木腐病的初步研究

浙江省杭州的桑树和喜树感染一种层孔菌(暗黄层孔菌)后,形成树木木腐甚至枯死。发病严重度和土壤的酸碱度及湿度有密切关系。暗黄层孔菌在酸性米饭培养基培养成功。用石灰治疗有效。     

Bacillus sp.ZJU318脂肪酶发酵条件的优化及其酶学性质的研究

利用均匀设计法对Bacillus sp．ZJU318产酶的最佳培养基进行了快速优化研究。结果表明,其最适产酶培养基为：3．28％黄豆粉,0．023％蔗糖,0．075％K2HPO4,配制时的pH为12（灭菌后pH为8～9）;此外,其发酵的最佳条件为：发酵温度28℃,接种量20％,摇瓶装量20mL（250mL三角瓶）。在最适的发酵条件下,脂肪酶的发酵水平可达24．7U／mL。Bacillus sp．ZJU318脂肪酶作用的最适温度为45℃,40℃保温1h,活力几乎没有损失;但是,在50℃和60℃的条件下保温1h后,酶活降低得比较明显;酶作用的最适pH为9．0。在pH7～10,该脂肪酶较稳定,但是在酸性的环境中,酶的稳定性较低。