黑荆木材及其KP、CTMP的纤维形态研究

研究表明黑荆木材１—３年生密度为０．５９—０．６５ｇ／ｃｍ３，５—１０年生为０．７２ｇ／ｃｍ３；１—７年生木材成分变化不大，纤维素在４５％以上，半纤维素在２５％以下，木素在２１％以下。比较６年生黑荆木材及其ＫＰ、ＣＴＭＰ的纤维形态，纤维长度在０．７６ｍｍ以上的，木材为７２．０４％、Ｋｐ为７２．２２％、ＣＴＭＰ为８２．５８％；平均纤维长度木材为０．８５６ｍｍ、ＫＰ为０．８４５ｍｍ、ＣＴＭＰ为１．１６５ｍｍ；纤维宽度在１２一２４μｍ，木材为９２．６２％、ＫＰ为９２．８６％、ＣＴＭＰ为３４．６３％；平均纤维宽度木材为１５．６μｍ、ＫＰ为１５．８μｍ、ＣＴＭＰ为３０．７μｍ；长宽比木材为５４．９、ＫＰ为５３．３、ＣＴＭＰ为３７．９。     

甘蔗果糖-6-磷酸,2-激酶/果糖-2,6-二磷酸酯酶基因(F2KP)的克隆及其功能研究

果糖-6-磷酸,2-激酶/果糖-2,6-二磷酸酯酶(fructose-6-phosphate,2-kinase/ fructose2,6-bisphosphatase,F2KP)是影响生物碳积累和分配的调控关键酶,同时也是一个具有激酶和酯酶两种催化活性的双功能酶.本研究在已获得甘蔗(Sacc harum officinarum)蔗叶F2KP(命名为SoF2KP-L)的基础上,以蔗茎cDNA为模板克隆获得不同长度的同源片段,分别命名为SoF2KP-S1、SoF2KP-S2和SoF2KP-S3.生物信息学分析结果显示,SoF2KP-L翻译的蛋白具有完整的激酶和酯酶结构域,SoF2KP-S1、SoF2KP-S2和SoF2KP-S3所含开放阅读框长度均小于SoF2KP-L,其中SoF2KP-S1翻译的蛋白只具残缺的激酶结构域;SoF2KP-S2翻译的蛋白具完整激酶结构域但缺失酯酶结构域;SoF2KP-S3只能翻译数个氨基酸即终止翻译.选择双功能域完整的SoF2KP-L构建表达载体,农杆菌(Agrobacterium tumefaciens)介导转化烟草(Nicotiana tabacum).RT-PCR证实,SoF2KP-L在转基因植株成熟叶中转录表达.碳水化合物等生理指标测定结果表明,转基因植株成熟叶片中可溶性总糖/淀粉、还原糖/淀粉、蔗糖/淀粉比值均有不同程度的升高,碳水化合物含量和相关分配比率发生改变.研究结果提示,甘蔗中可能存存不同的F2KP转录产物,并初步证实甘蔗SoF2KP-L在光合组织中对蔗糖和淀粉的分配起到一定的调控作用,为进一步研究甘蔗F2KP基因的功能及为甘蔗分子育种提供参考依据.     

日本落叶松AS-AQ浆和KP浆的漂白特性比较

为深入了解日本落叶松的纸浆物理性能,该文以日本落叶松AS-AQ浆为原料,对纸浆的漂白特性进行了系统研究,并与KP浆的漂白特性进行了比较.研究结果表明:在常规CEH三段漂白中,最佳有效氯用量为8%,NaOH用量为2.5%,漂白纸浆的白度可达到73%(ISO).在CDEHD漂白中,最佳有效氯用量为9%,EH段NaOH的合理用量为2%,纸浆白度能够达到7.9%(ISO).在D/CE1D1E2D2和DE1D1E2D2漂白中,当总有效氯用量为7.9%时,两种漂白流程都能将纸浆漂到83%(ISO)的高白度.采用过氧化氢加强氧漂再加两段过氧化氢漂白的漂白流程（即OPQP1P2）可以将白度为27%(ISO)的纸浆漂到76%(ISO).无论是漂白浆还是未漂浆,AS-AQ浆的聚合度都在KP浆之上.      

An engineered anti-idiotypic antibody-derived killer peptide (KP) early activates swine inflammatory monocytes,CD3+CD16+ natural killer T cells and CD4+CD8α+ double positive CD8β+ cytotoxic T lymphocytes associated with TNF-α and IFN-γ secretion

This study evaluated the early modulation of the phenotype and cytokine secretion in swine immune cells treated with an engineered killer peptide (KP) based on an anti-idiotypic antibody functionally mimicking a yeast killer toxin. The influence of KP on specific immunity was investigated using porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2) as ex vivo antigens. Peripheral blood mononuclear cells (PBMC) from healthy pigs were stimulated with KP and with a scramble peptide for 20 min, 1, 4 and 20 h or kept unstimulated. The cells were analyzed using flow cytometry and ELISA. The same time-periods were used for KP pre-incubation/co-incubation to determine the effect on virus-recalled interferon-gamma (IFN-γ) secreting cell (SC) frequencies and single cell IFN-γ productivity using ELISPOT.KP induced an early dose-dependent shift to pro-inflammatory CD172α⁺CD14^+high monocytes and an increase of CD3⁺CD16⁺ natural killer (NK) T cells. KP triggered CD8α and CD8β expression on classical CD4⁻CD8αβ⁺ cytotoxic T lymphocytes (CTL) and double positive (DP) CD4⁺CD8α⁺ Th memory cells (CD4⁺CD8α^+low CD8β^+low). A fraction of DP cells also expressed high levels of CD8α. The two identified DP CD4⁺CD8α^+high CD8β^+low/+high CTL subsets were associated with tumor necrosis factor alpha (TNF-α) and IFN-γ secretion. KP markedly boosted the reactivity and cross-reactivity of PRRSV type-1- and PCV2b-specific IFN-γ SC. The results indicate the efficacy of KP in stimulating Th1-biased immunomodulation and support studies of KP as an immunomodulator or vaccine adjuvant.     

Value-addition of agricultural wastes for augmented cellulase and xylanase production through solid-state tray fermentation employing mixed-culture of fungi

Solid-state fermentation (SSF) was performed to evaluate the potential of agricultural residues for the production of cellulase and hemicellulase using individual and mixed cultures of Aspergillus niger and Trichoderma reseei. The maximum filter paper (FP) cellulase activity of 13.57 IU/gram dry substrate (gds), 22.89 IU/gds and 24.17 IU/gds and β-glucosidase activities of 21.69 IU/gds, 13.58 IU/gds and 24.54 IU/gds were obtained with wheat bran medium at 96 h incubation period with A. niger, T. reseei and mixed-cultures of A. niger and T. reseei, respectively. Mixed-culture SSF using rice straw supplemented with wheat bran in the ratio 3:2 resulted in higher FP cellulase, β-glucosidase, endoglucanase (CMCase) and xylanase activities, compared to the activities obtained using mono-cultures. Similarly, higher FP cellulase, β-glucosidase, CMCase and xylanase activities of 35.8 IU/gds (96 h), 33.71 IU/gds (96 h), 131.34 IU/gds (120 h) and 3106.34 IU/gds (120 h) were achieved in the tray fermentation using rice straw with wheat bran in the ratio of 3:2. Results of present investigation showed that higher cellulase activity and an optimal combination of cellulase and β-glucosidase can be achieved through mixed-culture SSF in trays. The approach of utilizing negative cost agricultural wastes through tray fermentation for cellulase and hemicellulase production is expected to serve the objectives of: (a) management of wastes which would otherwise cause environmental pollution problems; (b) production of hydrolytic enzymes at low cost and; (c) simple technique requiring no sophisticated instruments with practical applications.     

LC-MS analysis reveals the presence of graminan- and neo-type fructans in wheat grains

This is the first study describing the fine structure of the main, individual fructan oligosaccharides present in wheat grains. Wheat grain fructan structure was investigated in developing wheat grains and in different tissues of mature grains with liquid chromatography-mass spectrometry. Fructan oligosaccharides with a low degree of polymerization (<5) were mainly of the graminan- and inulin-type in developing wheat grains during the first week after anthesis. Starting from 14 days after anthesis, neo-type fructans, fructans with an internal glucose, were observed for the first time. Several neo-type fructan structures were identified and their portion in the total fructan pool gradually increased during grain development. In the mature kernel, almost no differences were noted between the fructan distributions of wheat flour and two wheat bran fractions enriched in either pericarp or aleurone tissue. Results are related to wheat fructan metabolizing enzymes and the nutritional implications are discussed.