玉米秸秆稀酸预水解液两种脱毒方法的研究

以玉米秸秆稀酸预水解液为原料,研究了减压蒸发和络合萃取两种脱毒方法对乙酸等抑制物的去除情况。结果表明:玉米秸秆稀酸预水解液减压蒸发脱毒,糠醛完全被去除,而5-羟甲基糠醛则基本不能被去除;当水解液浓缩5.80倍时,其浓缩液中乙酸质量浓度和去除率分别为4.06 g/L和60.45%。络合萃取脱毒的最佳条件:络合萃取剂的组成为30%三烷基胺+50%正辛醇+20%煤油,油水相比2∶1,温度25℃,时间60 min,此时脱毒液中乙酸质量浓度和去除率分别为1.43 g/L和52.33%,糠醛完全被去除,5-羟甲基糠醛的去除率为27.78%。     

草莓花药组培脱毒苗技术研究

通过对红太后草莓新品种进行花药培养，筛选出花药培养过程中各阶段适宜的培养基，并成功对试管苗进行炼苗、移栽，获得红太后草莓品种脱毒苗。     

Evidence of vacuolar compartmentalization of arsenic in the hyperaccumulator Pteris vittata

Pteris vittata can hyperaccumulate arsenic （As） to 〉1% of its dry weight without showing any signs of toxicity, indicating the existence of effective plant-internal detoxificaUon mechanisms. Although vacuolar compartmentalization is known to play an important role in heavy metal detoxification and tolerance, direct evidence of arsenic compartmentalization in this hyperaccumulator was lacking. Here we report the subcellular localization of As in the callus of P. vittata. The callus induced from gametophytes of P. vittata exposed to 0.2 mmol/L arsenate for 20 days were examined by directly isolating cell walls, protoplasts and vacuoles, and determining arsenic concentrations. Of the total As in the callus, about 94% was in the protoplast, and of that, 91% was present in the vacuoles, indicating that vacuoles are a major storage site for As in P. vittata. In addition, the changes in the chemical components of vacuoles were analyzed by Fourier transform infrared spectroscopy （FTIR）.     

微生物法对蓖麻饼去毒的研究

探讨了用微生物发酵的方法对蓖麻碱和变应原的去除效果,比较了DT菌和JM菌对蓖麻碱、变应原的去除率及蓖麻饼中营养成分含量的变化.结果显示,经过DT菌处理5 d和JM菌处理15 d的蓖麻饼中,其蓖麻碱含量与去毒前比较,差异显著(P<0.05);DT菌处理10 d、15 d,JM菌处理5 d、10 d的蓖麻饼,其蓖麻碱含量与去毒前比较,差异极显著(P<0.01).对于变应原的含量,经过DT菌处理5 d和10 d的蓖麻饼与去毒前比较分别达到了显著(P<0.05)和极显著(P<0.01)的水平,其它各处理组均未检测出变应原.DT菌和JM菌在对蓖麻饼去毒的同时,使其营养成分产生了一定的损失,其中以JM菌处理5 d的影响程度最小,以DT菌处理15 d的影响程度最大.     

菜籽粕发酵脱毒的一些影响因素

报告了菜籽饼粕发酵脱毒的菌种复壮方法及脱毒辅助剂．应用芥子甙的酶分解产物异硫氰酸酯类，通过产物耐受性筛选法，获得提高了脱毒率的曲霉（Ａｓｐｅｒｇｉｌｕｓｓｐ．）菌株．从饲料添加剂中寻找到一种可增强发酵脱毒效果的脱毒助剂，并试验了影响发酵脱毒的各种因子．     

In vitro metabolism of the trichothecene 4-monoacetoxyscirpenol by fungus- and non-fungus-feeding insects

Summary The metabolism of the trichothecene 4-monoacetoxyscirpenol by intact gut tissue was determined in the fungus-feeding Nitidulid,Carpophilus hemipterus (L.) and the non-fungus-feeding caterpillars, the fall armyworm,Spodoptera frugiperda (J. E. Smith) and the corn earworm,Heliothis zea (Boddie). The primary metabolite was the hydrolysis product scirpentriol. The amount of metabolism by theC. hemipterus larvae was ca 10 times that of the caterpillars on a per mg protein basis, suggesting metabolic adaptation for feeding on fungi that may contain mycotoxins.Acknowledgment. The authors wish to thank S. Taylor for technical assistance.The mention of firm names or trade products does not imply that they are endorsed or recommended by the U.S. Department of Agriculture over other firms or similar products not mentioned.     

发酵性丝孢酵母产油脂中纤维质糖化液脱毒工艺对比及优化研究

纤维质在进行稀酸水解糖化时,会产生一些对菌体发酵有抑制作用的物质。为了除去抑制物,提高纤维质糖化液的发酵产脂能力,对玉米秸秆稀酸水解液的脱毒产脂条件进行了优化,优化结果为：蒸煮20min,活性炭用量为1.0g/L,乙醛用量为 0.4g/L,黄孢原毛平革菌接种量(以孢子 计)为4×10⁸L^-1。此时,菌体生物量为21.2g/L,油脂含量为50.9%,油脂质量浓度为10.8g/L,糖油转化率为13.5%。     

Effect ofPlasmodium berghei infection on benzoic acid metabolism in mice

Summary The metabolism of benzoic acid was studied inPlasmodium berghei infected mice both in vitro and in vivo. Results of in vitro studies showed a considerable decrease in the ability of the infected liver to detoxify benzoic acid by hippuric acid formation. The in vivo study showed that hippuric acid formation decreases with increasing parasitemia and the emergence of benzoyl-glucoronide. This new pathway stops operating with further increase in parasitemia.     

Antiquitin, a relatively unexplored member in the superfamily of aldehyde dehydrogenases with diversified physiological functions

Antiquitin is a member of the aldehyde dehydrogenase superfamily. Sequence analyses indicate that the protein is highly conserved from plants to animals. The plant antiquitins are generally believed to play a role in osmoregulation and/or detoxification. The physiological functions of animal antiquitins remain largely elusive, their involvement in a number of human diseases has been implicated. Received 28 February 2006; received after revision 13 July 2006; accepted 31 August 2006     

重金属污染对土壤动物的影响

讨论了土壤重金属污染的内涵,从酶活性和分子结构两方面来说明重金属对土壤动物危害的机理。重金属对土壤动物机体酶活性产生诱导和抑制作用,重金属会破坏组织细胞的微结构,使土壤动物的群落结构呈现简单化和不稳定化,土壤动物对重金属的防御,主要包括土壤动物的特殊解毒策略和回避策略,可通过释放土壤动物来修复被重金属污染的土壤。