类球红细菌空间诱变效应研究

目的利用空间诱变手段处理类球红细菌,通过诱变后菌株生理生化情况的变化,筛选辅酶Q10(CoQ10)高产菌株,为空间诱变手段筛选产业化菌株的应用提供实验和理论依据。方法利用返回式卫星搭载类球红细菌,检测搭载后菌株的抗逆性及发酵CoQ10能力。结果空间搭载后筛选到生长温度、pH值、盐浓度范围变宽,抗逆性增强的菌株,同时菌落颜色出现乳白色、粉红色等颜色变异菌株。从颜色变浅的变异菌株中筛选到一株CoQ10高产菌,发酵生产CoQ10比对照高73.13%。结论与传统单因素诱变方式相比,空间诱变是多因素综合作用,诱变效果明显,能获得高抗逆性和高CoQ10生产能力的突变株,可以作为产业化菌株筛选的诱变方式。     

"神舟"4号空间飞行对搭载的转谷氨酰胺酶链霉菌选育的影响

目的利用“神舟”4号无人飞船搭载生产微生物转谷氨酰胺酶(MTG)的链霉菌株,进行工业实用性微生物菌种的空间诱变育种研究,定向选育高产酶突变菌株。方法将产酶茵株链霉菌WZFF．L—M168(2．60u／ml)以孢子和培养基中添加或不添加诱变剂亚硝基胍(NTG)的斜面培养形式搭载飞船后,采用蛋白质交联絮凝-沉淀实验方法初筛出正突变菌株,再采用摇瓶发酵产酶分析实验进行复筛驯化实验。结果实验首先发现在各种宇宙空间环境因素的综合作用下,搭载菌株的菌落形态发生明显变化,特定形态与产酶能力有一定正相关性。根据菌落形态特征从各搭载试管组中分离的733搭载突变株经系列选育驯化后,得到一系列MTG生产能力显著提高的优良搭载突变菌株。其中,最高产酶菌株在利用小型生化反应器进行发酵培养的产酶效果良好,酶活提高了40％以上,达到3．62u／ml,超过现有国际最高水平。结论将产MTG菌种搭载“神舟”4号飞船,并进行严格的菌种驯化选育,获得了具优异性能的高产酶搭载突变株,表明空间诱变育种效果显著。     

推理选育林可霉素高产菌株

目的推理选育林可霉素高产菌株。方法根据林可霉素的生物合成途径,对其产生菌林肯链霉菌(Streptmyces Lin-colnsis)进行连续递进推理选育,出发菌株SL369经过UV诱变和多次单菌落分离,筛选林可霉素、L-酪氨酸和α,D-吡喃半乳糖抗性突变株。结果获得高产菌株SL-42,生产能力提高48%,上罐发酵证实,达7 900μ.ml-1以上,为企业赢得较大经济效益。结论推理选育可得林可霉素高产菌株,且高产性能及其遗传特性较为稳定。     

搭载后红曲霉菌突变株的染色体DNA随机扩增多态性分析研究

目的：研究太空诱变机理。方法：利用染色体DNA随机扩增多态性分析(RAPD)技术,对经“神舟”3号返回式飞船搭载的高产红曲霉菌进行DNA多态性分析。结果：突变株基因组DNA发生了改变。结论：突变株洛伐他汀产量的提高与其遗传基因的变异有关,太空诱变是通过改变搭载菌株的遗传基因而实现的。     

空间条件对棘孢小单孢菌的诱变效应

１９９０年１０月将庆大霉素产生菌一棘孢小单孢菌（Ｍ．Ｅｃｈｉｎｏｐｏｒａ）搭载“９０１０５”科学返地卫星，返地后进行观测筛选 。其主要结果：菌株生长周期发生变异，均出现生长周期缩短或延长的超亲类型，经自然分离得到一些稳定的生长周期短的突变体；菌株产抗生素能力变异幅度较大，平均水平提高，高产菌株提高，产量正突变纺为２７．２７％，负突变率不高。卫星搭载后的菌株中，初筛选时最优菌株比对照增产２７．５５％     

利用返回式科学卫星选育优良双歧杆菌

为选育优良菌株，利用返回式科学卫星搭载了双歧杆菌，对搭载后的菌株进行了复壮和分离，从中筛选出一株空间变异菌株Ｓｐａｃｅ ＢｂＮＣ－８。经一系列生物学试验证明，它具有生长速度快，对高温、过氧化氢、乙醇耐受性明显提高，无耐药性质粒，对动物无毒副作用等良好生产性状。     

泰乐菌素产生菌的空间诱变育种研究

目的研究弗氏链霉菌(streptomyces fradioe)在空间条件下的变异规律,并筛选高产菌株应用于工业生产。方法将弗氏链霉菌(streptomyces fradiae)9940S^ _86连续经“神舟”1、3、4号飞船搭载进行太空诱变育种,统计筛选结果,初步探讨泰乐菌素产生菌在空间条件下的变异规律。结果复筛后得到48株效价较出发菌株提高20％以上的菌株,其中总效价最高达到14950μg／ml(摇瓶),较出发菌株提高91．5％。结论弗氏链霉菌的空间诱变受飞行时间影响较大。菌株经多次搭载后其产量变异有累积作用,并且产量变异和形态变异存在相关性。通过中试、生产实验,最终选定产量较出发生产菌株提高18％的T1—156—84—23菌株投入试生产。     

新疆传统奶疙瘩中乳酸菌的分离及筛选

以溴甲酚绿BCG牛乳营养琼脂为培养基,对采自新疆伊犁、塔城、乌鲁木齐白杨沟的传统奶疙瘩中的乳酸菌进行了分离,经形态学和生化试验,得到初步定为乳酸菌的菌株18株.将经牛乳传代试验筛选得到的遗传性能稳定的5株乳酸菌并组合应用于牛乳发酵,分析其成品的组织状态、风味和乳清析出状况,测定菌株的发酵活力、凝乳时间、乙醛以及双乙酰的含量,筛选出感官性状好、风味独特、产酸能力较强的乳酸菌组合2组,可应用于发酵乳制品的生产.     

海洋放线菌和真菌野生株及其突变株的分离培养与抗肿瘤活性筛选

目的:从海泥样品中分离培养并筛选获取野生型与突变型药源微生物抗肿瘤活性菌株.方法:通过单菌落挑选与划线培养,分离纯化野生菌株;利用核糖体工程抗性筛选技术.筛选获得抗生素抗性突变株;用K562细胞,采用MTT法测试发酵样品的抗肿瘤活性.结果:从天津塘沽驴驹河渤海湾潮间带海泥样品中分离得到放线菌126株、真菌29株,其中,在100μg/ml样品浓度下抑制率大于20%的放线菌17株、真菌3株,在1000μg/ml样品浓度下抑制率小于5.5%的无活性放线菌19株.以1000μg/ml样品浓度下抑制率为4.8%的无活性放线菌野生株L8-5x为原始茼,经抗性筛选获得链霉素抗性突变株78株,其中在100μg/ml样品浓度下抑制率大于25%的活性突变株2株.结论:所获野生型与突变型抗肿瘤活性菌株为后续新药筛选提供了药源微生物活性菌株.由无活性菌株转化获取活性突变株的研究结果表明,已分离得到的大量无活性菌株也是可转化获取药源活性突变株的很好资源.     

Avermectin B1a高效突变株的选育及发酵条件的优化

目的筛选获得Avermectins B1a高效突变菌株。方法通过离子注入诱变、紫外线与氯化锂复合诱变法处理阿维链霉菌出发菌株N-5-9。获得高效突变株,再对其进行发酵条件的优化,寻找最适发酵培养条件。结果筛选获得Avermectins高效突变菌株A-30-6,总效价达到6988.2μg·ml-1,B1a含量达到79.4%,较出发菌株N-5-9的B1a组提高46.3%。结论利用离子注入诱变、紫外线与氯化锂复合诱变方法,诱变效果显著,再进行发酵条件的优化,获得目的菌株。     

俄生物卫星的家蚕搭载飞行实验

在俄罗斯第１０颗生物卫星上，家蚕滞育卵，非滞育卵，熟蚕，蚕蛹，蚕茧和蚕蛾完成了１２天的空间飞行和吐丝结茧，交配产卵，胚胎发育，化蛹化蛾等一系列行为和变态过程，发现飞行组与对照组比较家蚕发育过程缩短；滞育卵在飞行中孵化率提高；在飞行中产卵所发育的家蚕的蚕丝质量有提高的趋势，并观察到三个飞行品种家蚕出现明显的形态学变异现象。     

Dynamics of the body liquids and composition in long-duration space flight (bio-impedance analysis)]

Bio-impedancemetiy was used to study dynamics of the human hydration status and body composition aboard the International space station (ISS). Body liquids in 12 Russian crewmembers were found reduced in different periods of space flight: the total, intra- and extracellular liquid volumes became less by 5.2 to 10.4% on the group average as compared with baseline values. In-flight changes in body composition also displayed a consistent pattern. While the lean mass loss was insignificant averaging 1.9-4.0%, the fatty mass gain averaged 4.6 to 8.2% in the initial three months on flight. We conclude that the human body hydration status falls along with the muscular mass reduction and fatty mass gain during long-duration space flight.     

航天辐射危害及其防护剂研究进展

目的综述国内外航天辐射危害及防护剂研究的进展，提出加强防护剂研究的建议。资料来源与选择国内外有关航天辐射剂量、生物效应的数据以及航天辐射防护剂研究的文献。资料引用相互和独立地引用文献资料，共引用23篇参考文献。资料综合就载人航天辐射危害、航天辐射损伤的生物学效应以及航天辐射防护剂研究发展方向等3个方面进行综合。结论航天辐射防护剂研究应予加强。     

Energy reactions in the skeletal muscles of rats after short-term space flight on Kosmos-1514

Ten hours after the 5-day space flight on Cosmos-1514 rats were examined for oxidative phosphorylation in mitochondria isolated from the posterior femoral muscles as well as for Krebs cycle enzymes and glycolysis in the mitochondrial and cytoplasmic fractions of the muscles. The mitochondrial respiration rate in various metabolic states was similar in flight rats and vivarium controls. After flight calculated parameters of energy efficacy of respiration as well as activity of malate dehydrogenase, isocitrate dehydrogenase and total lactate dehydrogenase remained unchanged. Unlike the flight rats, the synchronous controls showed signs of the stress-reaction: uncoupling of oxidative phosphorylation and oxalacetate inhibition of succinate dehydrogenase. Comparison of these findings with those from prolonged space flights indicates that inhibition of oxidative metabolism and glycolysis in mixed muscles which was demonstrated in the 20-day space flight does not develop immediately after launch but occurs within the time interval between mission days 6 and 18.     

航天飞行和模拟微重力下微生物次级代谢研究与太空微生物制药

随着人类对宇宙的不断探索,大量研究观察到微生物次级代谢在航天飞行中的变化,为人类利用太空环境进行高产和高质量微生物制药带来了希望。研究者认为,太空环境下微生物生长停滞期缩短,更早进入生长期,更早产生次级代谢产物。由于空间飞行的稀缺性和高昂成本,研究者利用微重力模拟设备进行微生物次级代谢研究。目前,不同的航天飞行和模拟微重力下微生物次级代谢研究并未观察到趋势相对一致的结果,其表型变化背后的分子生物学机制也有待进一步研究。太空微生物制药利用太空诱变筛选具有商业和医学价值的制药微生物菌株,这种航天飞行后地面筛选的模式具有无法控制诱变方向、被动筛选的缺陷,有待相关诱变通路进一步研究后予以改进。     

Ionizing radiation impacts photochemical quantum yield and oxygen evolution activity of Photosystem II in photosynthetic microorganisms

Purpose: Long-term space exploration requires biological life support systems capable of coping with the deleterious space environment. The use of oxygenic photosynthetic microorganisms represents an intriguing topic in this context, mainly from the point of view of food and O₂ production. The aim of the present study was to assess the effects of space ionizing radiation exposure on the photosynthetic activity of various microorganisms.

Materials and methods: Ground-based irradiation experiments were performed using fast neutrons and gamma rays on microorganisms maintained at various light conditions. A stratospheric balloon and a European Space Agency (ESA) flight facility were used to deliver organisms to space at the altitude of 38 and 300 km, respectively. During the balloon flight, the fluorescence activity of the organisms was real-time monitored by means of a special biosensor.

Results: The quantum yield of Photosystem II (PSII), measured directly in flight, varied among the microorganisms depending on the light conditions. Darkness and irradiation of cells at 120 and 180 μmol m^?2 s^?1 enhanced the radiation-induced inhibition of photosynthetic activity, while exposure to weaker light irradiance of 20 and 70 μmol m^?2 s^?1 protected the cells against damage. Cell permanence in space reduced the photosynthetic growth while the oxygen evolution capacity of the cells after the flight was enhanced.

Conclusions: A potential role of PSII in capturing and utilizing ionizing radiation energy is postulated.     

Inflight exercise affects stand test responses after space flight

PURPOSE: The purpose of this study was to determine whether exercise performed by Space Shuttle crew members during short-duration space flights (9-16 d) affects the heart rate (HR) and blood pressure (BP) responses to standing within 2-4 h of landing. METHODS: Thirty crew members performed self-selected inflight exercise and maintained exercise logs to monitor their exercise intensity and duration. Two subjects participated in this investigation during two different flights. A 10-min stand test, preceded by at least 6 min of quiet supine rest, was completed 10-15 d before launch (PRE) and within 4 h of landing (POST). Based upon their inflight exercise records, subjects were grouped as either high (HIex: > or = 3 times/week, HR > or = 70% HRmax, > or = 20 min/session, N = 11), medium (MEDex: > or = 3 times/week, HR < 70% HRmax, > or = 20 min/session, N = 10), or low (LOex: < or = 3 times/week, HR and duration variable, N = 11) exercisers. HR and BP responses to standing were compared between groups (ANOVA, P < or = 0.05). RESULTS: There were no PRE differences between the groups in supine or standing HR and BP. Although POST supine HR was similar to PRE, all groups had an increased standing HR compared with PRE. The increase in HR upon standing was significantly greater after flight in the LOex group (36 +/- 5 bpm) compared with HIex or MEDex groups (25 +/- 1 bpm; 22 +/- 2 bpm). Similarly, the decrease in pulse pressure (PP) from supine to standing was unchanged after space flight in the MEDex and HIex groups but was significantly greater in the LOex group (PRE: -9 +/- 3; POST: -19 +/- 4 mm Hg). CONCLUSIONS: Thus, moderate to high levels of inflight exercise attenuated HR and PP responses to standing after space flight.     

Anthropometric studies of crew members of Salyut-6 and Salyut-7

The paper presents body mass and leg volume measurements of 21 prime crewmembers of Salyut-6 and Salyut-7 flights. It was found that body mass variations were different in sign. In most crewmembers body mass decreased by 1.2-2.0 to 6.0 kg. In some crewmembers this parameter increased by 1.0 to 4.5 kg during the entire flight or at certain flight stages. This observation confirms the concept that metabolism produces an important effect on body mass variations. It also points out that the space diets used are adequate to metabolic requirements. Leg volume of all cosmonauts decreased in the following manner: the decrease was the greatest during the first flight day, slightly less during the first flight month and still less during the subsequent 2 or 3 months of flight. Exercises that were performed at a larger workload, especially during the second half of flight, seemed to help stabilize or occasionally increase leg volume.     

The effects of microgravity on ligase activity in the repair of DNA double-strand breaks

PURPOSE: In recent years, contradictory data have been reported about the effects of microgravity on radiation-induced biological responses in space experiments. The aim of the present study was to clarify whether enzymatic repair of DNA double-strand breaks is affected by microgravity using an in vitro enzymatic reaction system. MATERIALS AND METHODS: The DNA repair activity of T4 DNA ligase (EC 6.5.1.1) was measured in vitro for a DNA substrate damaged by restriction enzyme digestion during a US Space Shuttle mission (Discovery; STS-91). After the flight, the amount of ligated DNA molecules was measured using an electrophoresis method. RESULTS: Ligated products (closed circular DNA, open circular DNA and multimeric ligated products) were produced by T4 DNA ligase treatment of linear DNA containing double-strand breaks, and they increased with increasing T4 DNA ligase concentration (0-3 units per microg of plasmid DNA). Almost no difference in T4 DNA ligase activity was detected between the space experiments and the control ground experiments. CONCLUSIONS: No significant effect of microgravity on ligation of damaged DNA was found during space flight. Therefore, other mechanisms must account for the synergism between radiation and microgravity, if it exists.