调制过程中温度对雪茄外包皮烟叶碳水化合物动态变化的影响

研究了调制过程中不同温度条件下雪茄外包皮烟叶中的水分含量、总糖、淀粉及蔗糖转化酶、淀粉酶活性的动态变化.结果表明,在整个调制过程中,各个温度处理模式下淀粉酶和转化酶活性都呈现单峰变化趋势,在叶片变色期达到最大值.叶片含水率、总糖、淀粉含量均呈下降趋势,以叶片变色期下降速率最快.高温模式下转化酶、淀粉酶活性较强,调制后烟叶的总糖(2.13 mg.g-1)、淀粉含量(2.66 mg.g-1)较低,其外观质量优于中温、低温模式.方差分析表明,高温处理模式的淀粉酶活性、淀粉含量与中温、低温模式之间差异均达到显著水平,中温与低温模式之间差异不显著;转化酶活性、总糖含量低温与高温模式之间差异达到显著水平.低温与中温模式之间、高温模式与中温模式之间差异不显著.     

土壤中淀粉酶高产菌株的分离及产酶条件的优化

从土壤中分离到淀粉酶产生菌,获得产酶量相对较高的菌株,并从pH和培养温度两方面对产酶条件进行优化。实验结果显示,土壤中分离的菌株有较高的淀粉酶活力,产酶条件适用于工农业生产。     

玉米冷害机理及化学控制防御的效应

本实验结果表明,玉米芽期低温(3℃)处理,导致淀粉酶活性降低,麦芽糖较对照减少8.6mg/g 干重,可溶性糖含量减少5.5%,淀粉含量高8.1%;幼苗期低温处理1天和4天,叶绿素含量较对照分别减少0.13和0.29mg/g 干重;玉米生育后期,旗叶淀粉酶活性随播期推迟而减弱,第Ⅳ播期旗叶麦芽糖含量较第Ⅱ播期减少748μg/g 鲜重。试验还表明,松哈地区4月25日(第Ⅱ播期)左右,为玉米最佳播种期。在玉米雄穗分化早期,施用13.3～40g/亩乙烯利(Ethephon),平均增产8～12%;早玉米拔节期每亩叶面喷酒50公斤0.25%矮壮素(Cycoel),增产33.8%。     

鲤鱼肠道细菌及其淀粉酶对宿主消化的影响

本文就鲤鱼肠道细菌对其宿主的影响和细菌淀粉酶对宿主消化的影响作了探讨。从鲤鱼肠道筛选细菌菌株６３株，这上结细菌中淀粉酶产生菌分布较广，溶血毒素产生菌较少，且产毒素的６株菌无致病性。淀粉酶活力较高的ＣＣＩ１３９菌株的淀粉酶和鲤鱼肝胰淀粉酶的最适ｐＨ和反应产物都不相同。原位酶反应法显示鲤鱼肠道食物混合液及肠壁样品中均有细菌淀粉酶。本文结果证明了鲤鱼肠道不稳定的细菌群落，细菌淀粉酶对鲤鱼消化食物的淀粉起     

草鱼摄食后肝胰脏组织淀粉酶活性的变化

用含量均为45％的马铃薯淀粉、糊精、葡萄糖和45％马铃薯淀粉 0．5％Cr2O3为碳水化合物源的4种试验饲料饲喂草鱼，50d后测定消化组织的淀粉酶活性。结果表明，各试验组消化组织的淀粉酶活性在摄食后下降，肝胰脏、前肠、中肠、后肠淀粉酶活性的最低值分别出现在摄食后3h、3h、3—5h、5—8h，并且淀粉 Cr2O3组的淀粉酶活性低于淀粉组。     

Expression of pancreatic enzyme genes during the early larval stage of Japanese eel Anguilla japonica

ABSTRACT: To reveal the ontogeny of pancreatic exocrine function in the early larval stage of eel, cDNAs encoding major pancreatic enzymes, trypsinogen, amylase and lipase were identified from the Japanese eel Anguilla japonica and their expression pattern in larvae was analyzed. The cloned eel trypsinogen precursor consisted of 224 amino acids and showed 82.2% identity to trypsinogen-2 of winter flounder Pleuronectes americanus . The eel amylase precursor consisted of 512 amino acids and showed 77% identity to winter flounder amylase. Eel pancreatic lipase was composed of 470 amino acids and had 58.3% of identity to human pancreatic lipase. In the eel larvae, mRNA expression of trypsinogen and amylase was first detected at 6 days post-hatching (d.p.h.), and the expression level increased between 7 and 8 d.p.h. In contrast, mRNA expression of lipase was first detected at 8 d.p.h. Eel larvae start to feed actively at 8 d.p.h. Thus, it was indicated that eel pancreas starts to synthesize digestive enzymes at 6 d.p.h. and acquires full function by the onset of exogenous feeding at 8 d.p.h.     

Effects of diet on amylase expression in the mosquitofish

Diets high in various carbohydrates were fed to mosquitofish,Gambusia affinis holbrooki, to determine the effects on amylase expression. Both amylase activity and amount of amylase protein were used as measures of amylase expression. Fish were fed for 21 days in one experiment, seven days in a second experiment and 24 h in a third. The first experiment compared responses of fish fed on a high-starch diet relative to a control diet. The second and third experiments compared responses on four diets relative to the control diet: maltose, starch, glucose, and glucose + cyclic adenosine monophosphate (cAMP). In the first two experiments whole visceral extracts were used. In the third experiment, gut and hepatopancreatic extracts were examined separately. Diet had a significant affect on the amount of amylase in all three experiments but affected amylase activity only in the 24 h experiment. Generally, glucose decreased amylase expression while maltose or cAMP + glucose increased it. Length of feeding period and tissue type also had significant effects on amylase expression.Paper IV on the amylase gene-enzyme system in fishes.     

昆明裂腹鱼淀粉酶活性研究

用碘─淀粉比色法研究鱼类离体消化器官淀粉活性,测得在最适pH和最适温度条件下,昆明裂腹鱼胃、前肠、中肠、后肠和肝等主要消化器官淀粉酶活性分别为669.5、789.23、796.86、786.15和733.15个淀粉酶活性单位,淀粉活性最高的是中肠,最低的是胃。其最适pH为7.4~8.6,最适温度为30~45℃。     

三种鹿属动物血清淀粉酶同工酶的电泳研究

采用聚丙烯酰胺凝胶电泳法对３４头白唇鹿，５８头马鹿和１１头梅花鹿的血清淀粉酶同工酶进行了比较研究。结果发现：（１）３种鹿的血清淀粉酶都有ＡＭＹ１，ＡＭＹ２和ＡＭＹ３种同工酶，但白唇鹿ＡＭＹ１和ＡＭＹ２同工酶的相对迁移率小于马鹿和梅花鹿；（２）３种鹿的ＡＭＹ１同工酶都有ＡＭＹ１Ｆ和ＡＭＹ１Ｓ两种表型，以ＡＭＹ１Ｆ为优势表型（分别为６４．７１％，６８．９７％和８１．８２％）；（３）白唇鹿的ＡＭＹ２同工酶存在ＡＭＹ２ＡＡ，ＡＭＹ２ＡＢ和ＡＭＹ２ＢＢ３种表型，以ＡＭＹ２ＡＡ为优势表型（５０．００％）；（４）马鹿的ＡＭＹ２同工酶存在ＡＭＹ２ＡＡ，ＡＭＹ２ＡＢ，ＡＭＹ２ＢＢ和ＡＭＹ２Ｏ４种表型，梅花鹿存在ＡＭＹ２ＡＢ和ＡＭＹ２ＢＢ两种表型，以ＡＭＹ２ＡＢ为优势表型（分别为８９．６６％和９０．９１％）。     

青海八眉猪仔猪血浆淀粉酶活性的测定

采用碘—淀粉比色法对青海省湟中县 44头八眉猪仔猪 (公 2 4头、母 2 0头 )血浆淀粉酶 (AMY)活性进行了测定。结果八眉猪仔猪淀粉酶活性为 673 .63± 3 2 4.84U L ,且公、母猪间血浆AMY活性无显著差异 (P >0 .0 5 )。同时测定了血浆钙 ( 2 .0 9± 0 .2 6mmol L)和氯 ( 10 5 .94± 11.96mmol L)离子浓度。