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991.
【目的】建立酶法提取玉米芯膳食纤维方法,优化复合酶法改性玉米芯不溶性膳食纤维(IDF)制
备可溶性膳食纤维(SDF)工艺。【方法】以玉米芯为原料,通过单因素试验优化碱性蛋白酶、α- 淀粉酶和糖
化酶预处理提取玉米芯粗膳食纤维(TDF)条件,结合正交试验优化复合酶(纤维素酶和木聚糖酶)法改性 IDF
制备 SDF 工艺。【结果】生物酶法提取玉米芯 TDF 条件:料液比 1 ∶ 10、pH 9.0、1.4% 碱性蛋白酶 50 ℃酶解
60 min;pH 6.5、0.3% 的 α- 淀粉酶和糖化酶(1 ∶ 1)、60 ℃水解 60 min,IDF 得率为 69.35%。复合酶法改
性 IDF 最佳工艺为:pH 5.0、温度 50 ℃、纤维素酶 1.2%、木聚糖酶 1.2%、酶解时间为 6 h、料液比为 1 ∶ 10,
SDF 得率可达 22.16%。处理后的 SDF 持水力为 6.55 g/g,膨胀性为 6.69 mL/g,持油力为 4.65 g/g,分别比改性前
提高 40.26%、48.67%、74.16%。【结论】复合酶法改性玉米芯 IDF 制备 SDF 得率较单一纤维素酶和单一木聚糖
酶处理的 SDF 得率高,且显著提高产物 SDF 的持水力、持油力和膨胀性。 相似文献
992.
Modern potato breeding requires over 100,000 seedlings per new variety. Main reasons are (1) the increasing number of traits
that have to be combined in this tetraploid vegetatively propagated crop, and (2) an increasing number of traits (e.g., resistance
to biotic stress) originates from wild species. Pre-breeding by introgression or induced translocation is an expensive way
of transferring single traits (such as R-genes, coding for resistance to biotic stress) to the cultivated plant. The most important obstacle is simultaneous transfer
of undesired neighbouring alien alleles as linkage drag. Stacking several genes from different wild sources is increasing
this linkage drag problem tremendously. Biotechnology has enabled transformation of alien genes into the plant. Initially,
transgenes were originating mainly from microorganisms, viruses or non-crossable plant species, or they were chimeric. Moreover,
selection markers coding for antibiotic resistance or herbicide resistance were needed. Transgenes are a new gene source for
plant breeding and, therefore, additional regulations like the EU Directive 2001/18/EC were developed. Because of a strong
opposition against genetic modification of plants in Europe, the application of this Directive is strict, very expensive,
hampering the introduction of genetically modified (GM) crops and the use of this technology by small and medium-sized enterprises
(SMEs). Currently, GM crops are almost the exclusive domain of multinationals. Meanwhile, not only transgenes but also natural
genes from the plant species itself or from crossable plant species, called cisgenes, are available and the alien selection
genes can be avoided in the end product. This opens the way for cisgenic crops without alien genes. The existing EU directive
for GM organisms is not designed for this new development. The cisgenes belong to the existing breeders’ gene pool. The use
of this classical gene pool has been regulated already in agreements regarding breeders’ rights. We are proposing a step by
step approach starting with a crop and gene specific derogation and monitoring towards a general exemption of cisgenic plants
from the Directive. Two examples, i.e. development of cisgenic potato for resistance to Phytophthora infestans and cisgenic apple for resistance to Venturia inaequalis are discussed shortly for illustration of the importance of cisgenesis as a new tool for traditional plant breeding. Cisgenesis
is simplifying introgression and induced translocation breeding tremendously and is highly recommended for SMEs and developing
countries. 相似文献
993.
新世纪我国木材科学与技术展望 总被引:14,自引:2,他引:14
在新世纪到来之际,为了适应全球经济一体化,科技经济一体化以及国家经济体制改革和科技体制改革的发展要求,我国将加强木材科学与技术的知识创新和技术创新,对学科发展进行重大调整,知识创新将以人工林木材为主的植物材料的材质材性与生物形成和加工利用的关系方向有重大进展;技术创新将以企业为主,在以木材为主的植物资源加工利用技术,产品增值加工技术,木质材料性能,产品应用技术和环保技术方面有较大的突破,木材科学与技术学科的发展特点将更显交叉性和边缘性,向植物材料学,木基复合材料学,木质重组材料学,木质环境材料学,木结构环境工程学和木材化学和加工学等方面6发展。 相似文献
994.
五种桉树木材的吸声性能 总被引:5,自引:0,他引:5
本文以广西东门林场的人工林尾叶桉(Eucalyptusurophylla),尾巨桉(EucalyptusurophyllaE.grandis),尾园桉(E.urophyllaE.tereticornis),尾赤桉(E.urophyllaE.camaldulensis)和大花序桉(E.cloeziana)木材为主要材料,用驻波管法测试了五种桉树木材的吸声系数,比较了这些桉树木材的吸声性能,结果显示五种桉树木材的吸声系数在频率1000赫兹之内变化不大,之后随频率的增加吸声系数也在增加。在频率200至2000赫兹范围内,五种桉树木材的吸声系数差异不显著,在低频区域,尾叶桉的吸声性能较好。在所测试的声波频率范围内,桉木弦锯板的吸声系数高于径锯板;0.5厘米厚的锯材的吸声性能好于1.0厘米厚的锯材;因此,桉木板材的种类和板材的厚度影响其吸声性能,但五种桉树木材的吸声性能差异不显著。图2表4参6。 相似文献
995.
蓖麻毒蛋白的改性与抗癌活性 总被引:6,自引:0,他引:6
蒋旭红 《仲恺农业技术学院学报》2006,19(3):60-64
蓖麻毒蛋白对细胞杀伤是非特异性的,因此有严重的毒副作用.文章对蓖麻毒蛋白的改性及改性后的抗肿瘤活性进行了综述,并对由蓖麻毒蛋白构建的免疫毒素在肿瘤的治疗中显示出的良好应用前景进行了讨论. 相似文献
996.
Mustafa Kemal Yalinkiliç Tsuyoshi Yoshimura Munezoh Takahashi 《Journal of Wood Science》1998,44(2):152-157
Phenylboronic acid (PBA) was tested in terms of boron leachability from treated wood. In addition, the fungal and termiticidal efficacy of PBA-impregnated sugi (Cryptomeria japonica D. Don) wood was tested against the decay fungi Coriolus versicolor (L. ex Fr.) Quel. and Tyromyces palustris (Berk. et Curt) Murr., representing white-rot and brown-rot fungi, respectively, and the Formosan subterranean termite Coptotermes formosanus Shiraki. Ion chromatography analysis of hot water extracts of treated wood before and after leaching indicated that PBA is considerably resistant to water leaching, and saturation of the treatment solution increased the fixation ratio of boron in wood, whereas boric acid could not remain in wood impregnated even with the saturated solution. Decay test results revealed the excellent bioactive performance of PBA. Wood treated with 0.34% PBA solution was found resistant to both decay fungi, even after running-water leaching for 10 days and treatment with 1.00% PBA completely inactivated the Formosan subterranean termite for the leached specimens. Weight gain levels were 0.18% w/w (0.46kg/m3) and 0.99% w/w (2.49kg/m3) for these concentration levels, respectively, after being leached by running water. Contrary to the general belief that boron is a slow-acting toxicant against termites and unable to prevent mass loss of treated wood, PBA acted rapidly, and the mass loss caused by termites was low.This study was presented in part at the 47th annual meeting of the Japan Wood Research Society, Kochi, April, 1997 相似文献
997.
木醋液对盐碱土化学性质、酶活性及相关性的影响 总被引:4,自引:0,他引:4
通过土壤培养试验,将分别稀释300(M300)、100(M100)、50(M50)、20(M20)和0(未施木醋液设为CK)倍的木醋液灌施到含有盐碱土的盆钵中,研究木醋液对盐碱土化学性质、酶活性及其相关性的影响。结果表明:与CK相比,施用木醋液均可显著降低土壤酸碱度p H、电导率EC值,提高土壤易氧化碳、水溶性有机碳氮、铵态氮(NH4+-N)和硝态氮(NO3--N)含量,但其对土壤有效磷含量影响不显著。(2)施用木醋液后,M300、M100和M50处理均显著提高了土壤α-葡萄糖苷酶、β-葡萄糖苷酶、几丁质酶、亮氨酸氨基肽酶、酸性磷酸酶、碱性磷酸酶和脱氢酶活性;M20处理提高了土壤多酚氧化酶与过氧化物酶活性,但M20对其他土壤酶活性变化不显著。综合来看,灌施适宜浓度木醋液后,不仅可提高盐碱土酶活性,也会改善其土壤化学性质。 相似文献
998.
999.
高晓霞 《内蒙古农业大学学报(自然科学版)》2005,26(3):67-69
木制家具的质量控制应从家具产品形成的全过程入手,设计阶段做好事前控制,保证功能造型,结构用材的安全合理性;生产环节完善施工工艺做好产品质量形成的事中控制;检验环节严格执行产品质量标准,杜绝各类安全隐患,做到事后把关. 相似文献
1000.