外源铬对延胡索生理指标及抗氧化系统变化的影响

为探究不同浓度外源Cr6+处理下,延胡索（Corydalis yanhusuo）生理指标及抗氧化系统的变化情况,测定了延胡索植株内铬含量、株高、生物量以及抗氧化系统各项指标。结果表明：当土壤中Cr6+浓度在67.32~323.32 mg·kg-1范围内,随着土壤中Cr6+浓度的升高,延胡索体内Cr6+累积量增加。延胡索植株株高、生物量表现为先升后降趋势,当土壤中Cr6+浓度低于131.32 mg·kg-1时,延胡索生长受到促进,而且这种作用具有一定的浓度依赖性：当土壤中Cr6+浓度低于131.32 mg·kg-1时,超氧化物歧化酶（superoxide dismutase, SOD）有较高活性,将超氧阴离子自由基歧化分解为H2O2,此时过氧化物酶（peroxidase, POD）、过氧化氢酶（catalase, CAT）活性均呈上升趋势,将H2O2分解,延胡索植株的生长受到促进作用;当土壤中Cr6+浓度达到195.32 mg·kg-1后,延胡索受到的胁迫严重,SOD活性有较大幅度的下降,植株体内超氧阴离子自由基大量累积,延胡索植株生长受到抑制。     

耐高糖酵母的筛选及其在黄酒中的应用研究

从蜂蜜、葡萄、面包3种原料中提取天然酵母进行梯度驯化,再通过紫外诱变育种,筛选出具有耐高糖性质的酵母并对其相关特性进行研究,将筛选出的菌株应用于黄酒酿造过程。结果表明,筛选出的酵母可耐受的糖度、pH值、酒精度分别为40%,1.5和10%Vol,将其应用于黄酒发酵中,经过7 d发酵后,菌株降糖能力较传统菌株提高了20 g/L,酒精度提高了0.4%Vol,糖类物质转化率达到11%。采用自然驯化和紫外诱变育种相结合,得到适用于黄酒酿造生产的耐高糖酵母菌株。     

氨基修饰二氧化硅对Cr^3+和直接桃红B12的吸附

该试验以硅烷偶联剂KH-550为改性剂,乙醇为溶剂合成氨基二氧化硅。利用红外光谱、扫描电镜、原子吸收光谱、可见分光光度法对改性前后SiO 2进行表征,研究其对铬离子及染料直接桃红B12的吸附情况。结果表明:25℃恒温振荡20 min,改性SiO 2吸附重金属离子Cr^3+效果明显,当其用量为0.04 g时,吸附率达99.01%,而相同条件下未改性SiO 2对Cr^3+吸附率只有25.13%;将其用于染料直接桃红B12的吸附,改性后SiO 2吸附率达91.97%,相同条件下未改性SiO 2的吸附率仅为34.23%。     

传统山西老陈醋增香酵母菌的筛选及其特性研究

为选育山西老陈醋用微生物发酵剂,从传统发酵工艺生产的山西老陈醋中分离筛选到5株增香酵母菌。结合形态学和酵母菌26S rDNA Dl/D2区序列分析,初步鉴定Y1为酿酒酵母(Saccharomyces cerevisiae),Y26为毕赤酵母(Pichia scaptomyzae),Y30为假丝酵母(Candida humilis),Y68为红酵母(Rhodotorula sp.),Y70为盔形毕赤酵母(Pichia membranifaciens)。采用固相微萃取和气-质联用技术分析这5株酵母发酵液的主要挥发性成分。结果表明,醇类和酯类挥发性成分种类和组成差异较大;对这5株酵母菌进行耐酸性、乙醇耐受性、高温耐受性发酵试验,结果表明毕赤酵母Y26具有优良的耐酸性、乙醇耐受性。综合其具有高产乙酯类、低产高级醇的特性,毕赤酵母Y26有望开发为山西老陈醋的新型发酵剂。     

Mass Production of Freshwater Rotifer,Brachionus calyciflorus,Under Different Diets and Regimes

ABSTRACT

The production ability of freshwater rotifer, Brachionus calyciflorus, cultured with two algal species, Chlorella vulgaris, and Spirulina platensis, and a baker's yeast, Saccharomyces cerevisiae, were studied using semicontinuous culture method. B. calyciflorus was fed with the above three types of food at five different concentrations (125, 250, 500,750, and 1,000 μg/mL). Among the three different types of diet, maximum production of B. calyciflorus (489.20 ±10.91 individuals/mL; P < 0.05) was obtained with C. vulgaris, followed by S. cerevisiae, and S. platensis. Moreover, in each of the three diets, the maximum rotifer production was obtained at a particular concentration (C. vulgaris, 750 μg/mL; S. cerevisiae, 750 μg/mL; and S. platensis, 500 μg/mL) beyond which the rotifer production decreased. The peak production due to C. vulgaris (489 individuals/mL) was better than S. cerevisiae (321 individuals/mL) when the number of rotifers was considered. The present study indicates that the quantity and quality of food have a significant role on the rotifer production and that C. vulgaris at 750 μg/mL appears suitable to feed to rotifers for maximal production.     

光合细菌配合面包酵母与藻粉培养轮虫的实验

以面包酵母与一定量螺旋藻粉培养褶皱臂尾轮虫的过程中，添加光合细菌液进行实验。结果表明：光合细菌作为辅助性饵料，对轮虫的生长具有明显特殊的促进作用。4组实验显示：投喂适宜量光合细菌轮虫增殖明显加快，但与光合细菌添加量的增加不完全呈正比关系；投喂光合细菌新鲜培养液与老培养液轮虫增殖效果相近；投喂光合细菌只能作为辅助性饵料。当配合酵母、藻粉培育轮虫时，3者在饵料上起到了良好的互补作用，培养效果最佳。     

三种免疫添加剂对草鱼非特异性免疫功能的影响

在饲料中添加不同剂量的Vc、酵母多糖和壳聚糖,连续投喂42d,并在试验的第14、28、35和42天取样检测,研究其对草鱼血清溶菌酶活性、血清超氧化物歧化酶活性（SOD）活性、血清碱性磷酸酶（AKP）活性、补体C3、含量丙二醛（MDA）含量和血液白细胞吞噬活性共6种指标的影响。结果显示：实验组与对照组相比,饲料中添加Vc可以提高血清溶菌酶活性、SOD活性、AKP活性、补体C3含量和血液白细胞吞噬活性高,并降低MDA含量。添加酵母多糖可以提高血清溶菌酶活性、AKP活性、补体C3含量和血液白细胞吞噬活性,并降低MDA含量,但不能提高SOD活性。添加壳聚糖可以提高血清溶菌酶活性、SOD活性、AKP活性、补体C3含量和血液白细胞吞噬活性,但不能降低MDA含量。饲料中添加Vc、酵母多糖和壳聚糖均对草鱼的非特异性免疫功能具有一定的促进作用。     

Probiotic microorganisms and antiviral plants reduce mortality and prevalence of WSSV in shrimp (Litopenaeus vannamei) cultured under laboratory conditions

The protective effect of a probiotic mixture (PM) and antiviral plants, against the white spot syndrome virus (WSSV) in Litopenaeus vannamei , was evaluated in three experiments. The PM was composed of four lactic acid bacteria (LAB) and one yeast strain. The plant mixture was composed of Ocimum sanctum and commercial antiviral plants (VPH^®, HSV^®). Shrimp in each experiment (weighing 2.7±0.7, 11.5±1.3, 11.70±2.5 g) were cultured in 120-L plastic tanks and fed twice a day with commercial feed plus additives (plants or bacteria and yeast). Animals were monitored for the occurrence of WSSV by single-step and nested PCR. The PM and powdered antiviral plants added to the commercial feed showed an increase in survival and a decrease in the prevalence of WSSV in shrimp. The results showed that both the PM and the powdered antiviral plants can provide protection for shrimp against WSSV.     

酵母培养物和芽孢杆菌对凡纳滨对虾生长、蛋白酶活性和免疫性能的影响

研究了饲料中添加酵母培养物(益康XP)和芽孢杆菌(Bacillus)制剂对凡纳滨对虾(Litopenaeusvannamei)生长、肌肉成分、蛋白酶活性和免疫功能的影响。在基础饲料(对照组)中分别添加0.075%益康XP、0.100%益康XP、0.200%芽孢杆菌,饲养均重(5.57±0.21)g的凡纳滨对虾45 d。结果表明,添加0.075%益康XP、0.100%益康XP、0.200%芽孢杆菌分别提高凡纳滨对虾增重率17.24%、12.29%、20.18%,降低饲料系数14.28%、9.77%、12.03%,提高蛋白质效率16.49%、10.05%、12.98%(P<0.05);添加酵母培养物和芽孢杆菌对凡纳滨对虾肌肉组成成分没有影响(P>0.05);0.075%益康XP组、0.100%益康XP组、0.200%芽孢杆菌组肝胰脏蛋白酶活性较对照组分别提高25.24%、15.22%、54.92%(P<0.05);各试验组肠蛋白酶活性与对照组相比有所提高,但均未达到显著水平(P>0.05);0.100%益康XP、0.200%芽孢杆菌组凡纳滨对虾血清酚氧化酶活性、溶菌酶活性和超氧化物歧化酶活性均显著高于对照组(P<0.05);攻毒实验表明,感染溶藻弧菌后,芽孢杆菌组对虾第1、3、4天的累积死亡率均显著低于对照组(P<0.05),第4天时的免疫保护率达到27.1%,而添加益康XP对累积死亡率无显著影响(P>0.05)。综上所述,饲料中添加酵母培养物益康XP和芽孢杆菌均能改善凡纳滨对虾生长性能和消化功能,芽孢杆菌能增强凡纳滨对虾对溶藻弧菌的抗感染功能。     

酵母免疫多糖对受免斑点叉尾免疫应答的增强作用

在饲料中添加定量的酵母免疫多糖,投喂注射接种了福尔马林灭活的嗜水气单胞菌(Aeromonas hydrophila)菌苗的斑点叉尾(Ictalurus punctatus),28 d后通过测定供试鱼的增重量、血清中凝集抗体效价、溶菌酶活性、谷丙转氨酶活性(SGPT)、血清总蛋白含量、白细胞吞噬活性以及活菌攻毒后的免疫保护率(RPS),探讨了酵母免疫多糖对受免斑点叉尾免疫应答的增强作用。结果表明,用添加200.0 mg/(kg.d)酵母免疫多糖的饲料投喂受免斑点叉尾,不仅可以使受免斑点叉尾对灭活嗜水气单胞菌的免疫应答水平提高,增强抵抗嗜水气单胞菌人工感染的能力,而且还具有一定的促进生长和改善肝功能的作用。