鸟苷发酵过程的多尺度问题研究

以鸟苷发酵为对象,在生物反应器中以多尺度问题的角度,对在线计算机数据进行相关分析,结合中间代谢物及有关酶活性的检测,建立了以代谢流为核心的多尺度调控方法;又通过与代谢流迁移有关的动态化学计量分析,实现了对批式发酵过程的时变系统估算,建立了主体代谢与产物形成的支路代谢间,包括能量与物质流的关系模型;最后,把具有不同生产能力菌株的关键基因与基因库数据进行了序列比较,发现了本文研究的菌株已具备高产能力,即编码sAMP合成酶的基因发生移码突变以及pur操纵子的多处突变,而中心代谢流迁移是过程优化的关键。对开展微生物功能基因组学的研究和工业过程优化的问题进行了探讨,作者提出有必要从生物反应器的系统生物学高度来认识和解决所面临的问题。     

Effect of adement preparation and its low-molecular fractions on development of neurodegenerative processes in Drosophila melanogaster mutants

Neuroprotective and neuroactivative properties of Adement preparations and the influence of Adement and its low-molecular fractions (9-10 Da, 4-6 Da, 1-2 Da) on dinamics of neurodegenerations, viability and lifetime of Drosophila melanogaster mutants with changes of brain structures have been investigated. It was shown that Adement as neuroprotector causes the delay of neurodegenerative changes by 10-15 days and increase of lifetime by 14%. None of the studied low-molecular fractions did not reveal the better effect on these indices than the total preparation. The use of Adement as neuroactivating agent in the complex with other preparations (neuroprotective agent + neuroactivating agent + neuroretardant) is more effective as the development of neurodegenerative changes in mutant brain stops for 20-27 days depending on genotype and a mean lifetime increases by 10-33%.     

Effect of ionizing radiation on methylation of lysyl tRNA synthetase from rat liver

X-irradiation of animals with an absolutely lethal dose of 0.21 C/kg increases the incorporation of a methyl group into aminoacyl-tRNA-synthetases the radioactive label being traced in lysine, arginine, and histidine. The isolated protein methyltransferase methylated total preparations of aminoacyl-tRNA-synthetases and lysyl-tRNA-synthetase of rat liver in the in vitro experiments with the use of S-adenosylmethionine-14CH3 as a donor of methyl groups: the radioactive label was traced in arginine, lysine, histidine, aspartic and glutamic acids.     

(ADP-ribose)n-transferase activity of enterocyte nuclei during radiation injury of small intestine mucosa in rats

The (ADP-ribose)n transferase activity of enterocyte nuclei of small intestine is studied in rats in normal and under radiation injury of intestine mucosa. It is shown that kinetics of [14C]-NAD incorporation into the acid-insoluble fraction of enterocyte nuclei is of a two-step character when the medium contains 1-15 microM of NAD. The X-ray irradiation of animals (a dose of 0.21 cells per kg) evokes changes in the (ADP-ribose)n transferase activity in nuclei of enterocytes isolated 1-72 h after irradiation. The irradiation results in distortion of the two-step kinetics of (ADP-ribose) synthesis in nuclei. The most pronounced activation of this biopolymer synthesis occurs 1,24 and 36 h after irradiation. In other periods a decrease in the level of (ADP-ribose)n synthesis is observed. Changes in the (ADP-ribose)n transferase activity in nuclei of enterocytes reflect the phase character of radiation sickness course in the small intestine. Activation of these processes is supposed to be a result of intensification of molecular mechanisms of DNA molecule reparation.     

Properties of phosphoprotein phosphatase from the rat liver

Prosphoproteid phosphatase, an enzyme highly specific to lysyl-tRNA-synthetase and proteins of the high-molecular-multienzymic complex of aminoacyl-tRNA-synthetases, was isolated from the rat liver. The data of electrophoresis in 4-30% PAAG with the presence of DS-Na have shown that phosphoproteid phosphatase is homogeneous and its molecular mass is 56 kDa. The isolated phosphoproteid phosphatase is activated by 2.5 mM Mg2+, Mn2+ and is inhibited by ions of univalent metals ions--200 mM Na+, 5 mM K+ as well as by 1 mM ATP, ADP, AMP.     

Etiology and control of durian foliar blight and dieback caused by Rhizoctonia solani

Foliar blight and dieback of durian seedlings and trees in Peninsular Malaysia was found to be caused by Rhizoctonia solani (teleomorph - Thanatephoms cucumeris) The fungus grew well and produced abundant sclerotia at temperatures higher than 24°C with an optimum at 28°C. It grew poorly at 35°C and did not grow at 10°C. The strains studied were found to belong to the anastomosis group AG-1. They were pathogenic on durian, papaya, cucumber, long bean, Mikania weed, padi, musk melon, mung bean, Zoysia grass, Bermuda grass, and St Augustine grass. They were mildly pathogenic on groundnut, and non-pathogenic on maize, guava and Brassica‘pak choy’. The disease was effectively controlled by foliar sprays of pencycuron and benomyl; triadimefon and an antagonistic bacterium suspension treatment were less effective and quintozene-etridiazole mixture gave poor disease control.     

Growth Regulator Interactions in the Growth of the Shoot System of Avena sativa Seedling: II. THE GROWTH OF THE FIRST LEAF AND THE COLEOPTILE1

1. Studies have been made of the growth in culture medium of thecomponent parts of compositesegments excised from 3 to 7-day-oldAvena sativa seedlings and comprising portions of coleoptileand first leaf bases and various lengths of first internodetissue.
2. The effects of various concentrations of gibberellicacid (GA)and indole-3- acetic acid (IAA) alone and in combinationhavebeen studied on the growth of these organs.
3. Both GA andIAA stimulate the growth of coleoptile base tissuebut in combinationtheir joint effects are less than additive.No synergism occurs.
4. The growth of the first-leaf base is greatly stimulated byGAbut is inhibited by IAA. In combination, the stimulatoryeffectof GA (up to 1 0 p.p.m.) may be virtually eliminatedby evenlow concentrations of IAA (0.01 p.p.m.).
5. The inclusionof first internode tissue in the segments considerablyincreasesthe growth of first leaf base tissue but has no consistenteffecton the growth of coleoptile base tissue. The presenceof firstinternode tissue also greatly increases the degreeof growthstimulation invoked by GA but does not influence thedegreeof IAA inhibition. It is postulated that the first internodetissue is the source of an unknown growth factor necessary forGA action in the first leaf and potentiating the action of endogenousgibberellin.
6. Kinetin, adenine sulphate, glutarnine, glutarnicacid, asparagine,glycine, arginine, histidine, lysine, aneurin,and pyridoxinewill not simulate the effects of this unknowngrowth factorin the growth of leaf tissue. Like IAA, kinetinvirtually eliminatesthe GA stimulation of leaf growth.
7. Astudy of extracts of internode tissue in various solvents,analysedby paper partition chromatography and assayed by thegrowthof the first leaf base, has indicated the presence ofgrowthinhibitors and gibberellin-like substances but has failedtoisolate the postulated endogenous GA-synergist.
8. The implicationsof these results for growth correlations andthe hormone controlof shoot growth in Avena sativa seedlingsis discussed.

     

Genetic analysis of X-chromosome neurodegenerative mutants of Drosophila melanogaster induced by ethyl methansulfonate and nitrosoethylurea

In a series of Drosophila mutants with changes in the brain structure, some characters (reduced life span, behavioral changes, and neuronal loss in various brain regions) resemble symptoms observed in human patients with neurodegenerative diseases. In addition, similar specific phenotypes shared by different species suggest that common mechanisms underlie degeneration of their nerve cell. This study reports the results of a genetic analysis of new X-chromosome mutants with neurodegenerative changes in brain structure, which were induced by chemical mutagenesis. According to complementation test, all mutants were divided into three complementation groups, in which the life span and dynamics of neurodegenerative changes were studied. The life span of Drosophila melanogaster flies was found to depend on the state of their nervous system.     

Anatomic features of the interventricular septum in persistent atrioventricular canal

Twenty-two preparations of hearts with preserved atrioventricular canal have been investigated. Primary defect of the interatrial septum is a constant component of this pathological state. The size of the defect defines participation of the atria in formation of the atrioventricular canal. At the same time it is possible to distinguish the following anatomical varieties of abnormal development of the interatrial septum; oblique cleft in the oval fossa, partial absence of the valve in the oval orifice, perforation of the valve in the oval orifice, complete absence of the valve in the oval orifice and certain defects of the interatrial septum situating beyond the oval fossa limits.