菌丝生长速度与呼吸消耗及胞外酶活性的关系

以棉籽壳为主料,对平菇、刺芹侧耳、黄伞、灵芝、金针菇和香菇原种培养期间的菌丝生长速度、呼吸消耗及胞外酶活性的关系进行了研究。结果表明,6种食用菌的菌丝生长速度与呼吸消耗正相关,而有机物的降解速率与胞外酶活性的大小没有相关性。     

球磨-酶解法制备纳米竹纤维的结构表征

采用机械球磨对竹纤维进行预处理,再经纤维素酶水解制备纳米竹纤维。通过光学显微镜(OM)、透射电子显微镜(TEM)、傅立叶红外光谱仪(FTIR)和X射线衍射仪(XRD)对竹纤维的形貌、组成、光谱学性能以及晶体特性进行了表征。实验结果表明:球磨法和酶解法在一定程度上都可以细化竹纤维;球磨预处理有助于竹纤维的酶解过程,且球磨-酶解法制备的纳米竹纤维粒径在100 nm左右;所制备的纳米竹纤维仍然保持竹纤维的基本化学结构,但球磨处理破坏了纤维素的结晶结构,其结晶度由64.15%降低到了38.55%。     

辣椒素的抑菌作用及其对某些保护酶活性的影响

 本文对辣椒素的抑菌作用和对寄主体内3种保护酶活性的影响进行了研究,结果表明3.57μg/mL-50.00μg/mL的辣椒素对辣椒枯萎病菌的菌丝生长都有明显的抑制作用,浓度愈高,抑制作用愈强。20μg/mL辣椒素对另外供试的8种病原菌的菌丝具有强烈的抑制作用,其中对番茄灰霉病菌抑制作用最强。辣椒素处理辣椒后1-6 d内,SOD、POD和CAT酶活性的平均增减比率值均明显高于对照,而且对根部和叶部3种保护酶活性的影响显著不同。     

硒和碘营养对蛋鸡不同组织抗氧化酶活性的影响

本试验旨在探讨饲粮中添加不同剂量的硒和碘对蛋鸡心脏、肝脏、脾脏和甲状腺中几种抗氧化酶活性的影响。288只33周龄的新罗曼蛋鸡,饲喂添加不同剂量硒和碘(0,0;0.2,0:0,0.2:0.2,0.2mgkg)的日粮12周,试验结果如下:硒缺乏时,心脏和肝脏中的GSHPx活性下降(P=0.073);碘缺乏时,心脏和肝脏中的CAT活性下降(P=0.055,P=0.097),肝脏中的GSHPx活性降低(P=0.093);硒碘互作对心脏(P<0.01)和肝脏(P<0.05)中的TSOD和CAT活性影响显著,对脾脏中的TSOD(CAT+GSHPx)值影响极显著(P<0.01)。结果表明:碘能够影响肝脏中含硒酶的活性,硒碘的互作能够影响心脏、肝脏和脾脏的抗氧化酶活性。     

山羊痘灭活疫苗免疫保护试验

将山羊痘GT4-STV42-56种毒在犊牛睾丸细胞上繁殖,收获毒液,用0.1%甲醛溶液灭活,加适量206佐剂,制成山羊痘油佐剂灭活疫苗.将疫苗以不同剂量皮下免疫接种不同种群的山羊.免疫后21 d,用AV40株强毒进行攻毒保护试验.结果显示,免疫剂量达0.5 mL时,疫苗对内蒙绒山羊的保护率为100%,对广西黑山羊的保护率为80%.实验表明,山羊痘灭活疫苗对山羊的免疫效果确实可靠.     

Mode of action of the anilino-pyrimidine fungicide pyrimethanil. 2. Effects on enzyme secretion in Botrytis cinerea

The effect of pyrimethanil on the levels of cell wall degrading enzymes secreted by Botrytis cinerea Pers. was investigated in diseased plant tissues and in liquid B. cinerea cultures. Total proteinase activity isolated from infected carrot slices which were treated with 5.0 μM pyrimethanil was decreased by 76%, 3 d after inoculation. Polygalacturonase, cellulase, proteinase and laccase activities were all decreased in the medium of three day-old cultures grown in the presence of pyrimethanil. The pyrimethanil concentrations resulting in 50% reduction in total enzyme activities (IC₅₀) were approximately 0.25 μM for polygalacturonase, cellulase and proteinase, and approximately 1.0 μM for laccase. No significant growth inhibition was observed at these pyrimethanil concentrations. Pyrimethanil did not inhibit the enzymes directly, nor did it inhibit the synthesis of cytosolic proteins. Therefore, it was proposed that the fungicide inhibits protein secretion at a post-translational stage in the secretory pathway. Large differences were found in the effects of pyrimethanil on the growth of B. cinerea in liquid cultures and on agar plates, depending on the composition of the medium. In liquid media containing cellulose and protein as carbon and nitrogen sources, growth inhibition occurred at 5.0 μM pyrimethanil, whilst no growth inhibition was observed with 50 μM pyrimethanil in malt extract. Similarly, growth occurred on potato/dextrose agar (PDA) at 0.5 μM pyrimethanil, but no growth was seen at this concentration on agars containing cellulose and protein. Thus it appears that pyrimethanil is most active in media where the fungus has to utilise extracellular enzymes to mobilise the nutrients it requires for growth.     

The Effect of Lecithin Supplementation on the Biochemical Profile and Morphological Changes in the Liver of Rats Fed Different Animal Fats

Sixty-four Wistar rats were divided into 8 equal groups and kept for 36 days in individual boxes. Three of the groups were given full synthetic diets containing various animal fats: beef tallow, pork fat or fish oil. A control group was fed the diets without the fat. The other four groups were fed the same diets with lecithin supplementation. At the end of experiment, sections taken from the liver were stained with haematoxylin–eosin and Sudan III to indicate fat infiltration. Liver enzyme levels, total bilirubin, albumin and two products of lipd metabolism were measured in serum from all the animals. The addition of lecithin to the diets did not influence the level of enzymes in the serum except in rats fed the diet containing beef tallow. A relationship between the type of diet, lecithin supplementation and the total cholesterol concentration in serum was observed. The concentration of HDL-cholesterol was only influenced by lecithin supplementation and that of triglycerides by the type of fat in the diet. The addition of lecithin to the diet was associated with proliferation of Kupffer cells, and an increased number of binuclear cells. Fatty degeneration of hepatocytes was less pronounced in all groups following lecithin supplementation. Lecithin supplementation of the diet did not elicit any pathological lesions and may be considered as a hepatocyte protector. This favourable effect of lecithin was most marked in the group of rats fed the fish oil.     

Studies on Normal Haematological and Serum Biochemical Values of the ‘Hijin’ Racing Camels (Camelus dromedarius) in Kuwait

Haematological estimations and serum biochemical analyses were made on 100 samples collected from clinically healthy Hijin racing camels (Camelus dromedarius) in Kuwait. The red blood cell counts, packed cell volume, haemoglobin concentration, mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration and total white blood cell counts were estimated. In the serum biochemical analyses, sodium, potassium, iron, calcium, phosphorus, magnesium, total bilirubin, blood urea nitrogen, creatinine, glucose, total protein and cholesterol concentrations were measured, as were the alanine aminotransferase, aspartate aminotransferase, -glutamyltransferase, creatine kinase and alkaline phosphatase activities. The results are discussed in relation to other findings reported in camels.     

Diagnosis of dehydratase inhibitors in melanin biosynthesis inhibitor (MBI-D) resistance by primer-introduced restriction enzyme analysis in scytalone dehydratase gene of Magnaporthe grisea

We have established a simple diagnosis method for rice blast fungus resistant to MBI-D. This involves the preparation of PCR templates directly from the lesions in combination with primer-introduced restriction enzyme analysis PCR (PIRA-PCR).