长日光周期对水稻幼穗发育的影响及其对光敏核不育水稻育性转换的作用研究

光敏核不育水稻晚粳农垦58S具有长日照下不育、短日照下可育的特点，是目前二系法杂交水稻应用的基础。对于其长日光周期引起雄性败育的特性已得到很多实验的支持，但这种光周期反应特性是光敏不育材料所特有，还是在水稻穗发育中普遍存在，目前尚不清楚。对这一问题的认识涉及到对光敏不育性本质的了解及对这一性状的有效利用，本文对此进行了系统的研究分析。 本研究以24种水稻品种包括光敏核不育系及常规水稻品种为材料，在控制光周期下进行。即利用16h长日照处理(LD)和l0h短日照处理(SD)及其不同组合，以抽穗期、叶龄、抽穗叶片总数、花粉育性、结实率、穗长、穗粒密度为指标，结合光敏不育系幼穗发育的形态解剖学特征，探讨了在整个水稻发育中包括叶片生长、幼穗分化以及穗发育等过程中，不同材料的光周期反应特征，尤其是二次枝梗期后的穗发育过程中的光周期反应特征。此外还分析了温度与光周期反应的关系及温度在光敏不育现象中的作用，并研究了代谢抑制剂对光敏不育特征的影响。 研究表明，光周期对水稻的出叶速度基本没有影响，但对水稻的抽穗叶龄有影响，长日照使抽穗叶龄增加而延迟其穗分化及抽穗。光周期还对幼穗分化后的穗发育过程有抑制延迟，作用，影响大小因品种而异，以对早稻、籼稻的影响最弱，对晚稻、粳稻的影响最强，与其穗分化中的感光性有明显的相关性。 除对抽穗期有影响外，穗发育阶段的长日光周期还影响着穗发育的其它性状，如使穗长增加，芒较长、稳粒密度降低，花粉育性降低，结实率下降。此外植株发育的其它性状也可受到影响，如剑叶发育不良表现为叶片缺少仅有叶鞘、倒二叶生长旺盛、植株较高等。同时几组不同组合的光周期处理结果均表明，长日光周期对水稻穗发育的影响主要发生在穗发育的前5-10天即颖花原基分化期、雌雄蕊原基分化期至花粉母细胞形成期。这些结果表明水稻的光周期反应不仅表现在茎端从营养生长向生殖生长的转换上（幼穗分化），而且还表现在幼穗分化完成后的穗发育过程中。长日光周期对晚稻穗发育均有抑制效应，且日长对稳发育的影响时期与光敏核不育水稻的‘育性转换敏感期’完全一致。因此在农垦58S中引起‘光敏不育’的原因很可能不是一种特殊的光周期反应，而是该材料雄性器官发生过程不能对长日光周期做出适当的反应。 对24种不同品种水稻的光周期反应表明，不同材料光周期反应特性不同。光敏不育系农垦58S与农垦58在对长日照的反应上也有较大不同，表现为前者在短日照下穗分化较快，在自然日照下抽穗较早。这表明除了育性不同外，农垦58S与农垦58在光周期反应特征上也有所不同，然而我们认为这种不同不是农垦58S表现光敏不育的主要原因。因为本研究中还发现，光敏不育系农垦58S与其可育回复突变体农垦58S(r)在抽穗期等光周期反应特征上相当一致，但在育性反应上却有较大不同，长日照下农垦58S(r)表现为雄性可育，而农垦58S表现为雄性败育。根据上述几方面的比较，我们认为光敏不育的机制很可能在于农垦58S突变体其雄性器官发育对环境不利信号的反应能力的变弱所致。 在本研究中发现，温度对水稻穗发育的影响表现在两个方面：一方面是通过影响光周期反应强弱而起作用，如高温可加强短日照下的穗分化和发育过程，高温亦可加强长日照对穗分化发育的抑制作用;另一方面是直接对器官发生过程产生影响，如在对短日照下光敏不育系和常规稻不同温度条件下处理时的结实率比较分析发现，常规稻的结实率与其抽穗扬花期的平均温度显著负相关，而光敏核不育水稻的结实率虽与抽穗扬花期的温度有一定相关性，但更与穗发育期的平均温度呈显著负相关，二者在受温度影响的作用时期上有显著差异，因此温度也可直接对雄性器官发育起作用。区分温度对光敏不育的两方面影响，同时考虑到光敏不育机制更有可能在于光敏不育系农垦58S雄性器官发育对环境信号反应能力的变弱的假设。我们就可以较好地理解农垦58S‘光敏不育’性状经杂交转育到对光周期弱感的籼稻中所出现的‘温敏不育性’。 核酸代谢抑制剂5-FU，2-TU对SD下的幼穗分化有较强抑制作用，使幼穗分化被迟滞，而2-BrDU和蛋白质合成抑制剂CHX、CL对其影响较小。抑制剂处理也不能诱导LD下的穗分化。 短日照下，5-FU可对穗发育有强烈抑制作用，可使常规品种农垦58及光敏不育系农垦58S穗畸形，颖花减少并发育不良，穗长缩短，枝梗减少，花粉败育甚至无花粉，结实率显著降低，其有效作用时期为穗发育的二次枝梗分化期至雌雄蕊原基分化期，与长日照诱导农垦58S败育的作用时期也完全吻合，5-FU对SD下穗发育的影响还可被核酸抑制剂的恢复剂乳清酸所部分恢复。其它代谢抑制剂如2-TU、CHX、CL等也可使农垦58S育性明显降饭，而所有这些抑制剂对常规可育的农垦58及农垦58S(r)的育性影响较小，表明它们与光敏不育系对抑制信号的反应能力有显著不同。 长日照下5-FU对LD下的农垦58S的幼穗发育也有很强的抑制作用，使稳长缩短，颖数减少，但它还可使部分LD下处理植株抽穗期较LD对照明显提前，并可使农垦58S育性部分恢复而有结实，说明5-FU还可对LD的抑制作用有抑制，通过对LD抑制作用的抑制使LD下的育性转换有部分恢复。其它代谢抑制剂在穗发育前期处理LD下农垦58S叶片均可看到植株在抽穗期较LD下提前5—8天的同时，其花粉育性有不同程度的提高，在高温长日下甚至有一定程度的结实率，表明各种抑制剂均可对穗发育中的光周期作用产生影响。 总之，本研究结果表明，短日植物水稻的光周期反应不仅存在于幼穗分化上，还存在于幼穗发育和花器官发生等发育过程中。幼穗发育的光周期效应表现为抽穗期、穗长、穗粒密度、结实率等多方面的变化，作用时期以穗发育早期的花器官发生阶段影响最大。作用强弱因品种不同而异，以粳稻和晚稻中作用较强。光敏不育突变的更主要变化可能在于农垦58S的雄性器官分化发育时对环境不利信号的反应能力变弱，导致其正常发育受阻，育性不能正常表达。温度在水稻穗发育上既可通过影响光周期反应而起作用，还可直接对穗器官发育产生影响而对育性表达起作用。此外我们还发现农垦58S与农垦58不仅在雄性育性上有显著不同，而且其光周期反应特性也有较大的差异。抑制剂处理结果也支持光敏不育系农垦58S的雄性器官发生过程较农垦58更易受抑制剂影响而育性降低，而抑制剂对长日光周期抑制作用的部分解除，可以使其育性有一定程度的恢复，也表明光周期对雄性育性的影响最为显著。这些结果可以帮助我们更加全面地认识光敏不育水稻的基本特性，从而为进一步开展光敏不育的转育及应用研究提供可靠的科学依据。

Molecular dynamics research of G249 and S249 substitutions of p53 protein.

,The molecular dynamics research of the core domain of p53 protein crystal structure shows that besides the stability in biochemistry this domain also shows a high stability in molecular mechanics. Based on that work, the residue R249 was substituted with amino acids Gly and Ser respectively, and molecular dynamics researches were performed separately. The results show that these substitutions cause a relax tendency between loop2 and 3 domains, leading to an alteration of the whole conformation of p53 core domain and ruining its stability. The results visually explains the mechanism of p53 changes in immunological and biochemical reactions, which are caused by 249 residue substitutions from 3-D structure variations.

Fragmentation effects on diversity of wasp community and its impact on fig/fig wasp interaction in Ficus racemosa L.

Habitat fragmentation usually results in alteration of species composition or biological communities. However, little is known about the effect of habitat fragmentation on the fig/fig wasp system. In this study, we compared the structure of a fig wasp community and the interaction between figs and fig wasps of Ficus racemosa L. in a primary forest, a locally fragmented forest and a highly fragmented forest. Our results show that, in the highly fragmented forest, the proportion of pollinator wasps is lower and the proportion of non-pollinator wasps is higher compared with the primary forest and locally fragmented forest. The proportion of fruits without pollinator wasps in mature fruits is also greatly increased in the highly fragmented forest. The proportion of galls in all female flowers increases in the highly fragmented forest, whereas the proportion of viable seeds does not change considerably. The disruption of groups of fig trees results in a decrease in pollinator wasps and even might result in the extinction of pollinator wasps in some extreme cases, which may transform the reciprocal interaction between figs and fig wasps into a parasite/host system. Such an effect may lead to the local extinction of this keystone plant resource of rain forests in the process of evolution, and thereby, may change the structure and function of the tropical rain forest.

Chronic Morphine Treatment Impaired Hippocampal Long-Term Potentiation and Spatial Memory via Accumulation of Extracellular Adenosine Acting on Adenosine A(1) Receptors

Chronic exposure to opiates impairs hippocampal long-term potentiation (LTP) and spatial memory, but the underlying mechanisms remain to be elucidated. Given the well known effects of adenosine, an important neuromodulator, on hippocampal neuronal excitability and synaptic plasticity, we investigated the potential effect of changes in adenosine concentrations on chronic morphine treatment-induced impairment of hippocampal CA1 LTP and spatial memory. We found that chronic treatment in mice with either increasing doses (20-100 mg/kg) of morphine for 7 d or equal daily dose (20 mg/kg) of morphine for 12 d led to a significant increase of hippocampal extracellular adenosine concentrations. Importantly, we found that accumulated adenosine contributed to the inhibition of the hippocampal CA1 LTP and impairment of spatial memory retrieval measured in the Morris water maze. Adenosine A(1) receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine significantly reversed chronic morphine-induced impairment of hippocampal CA1 LTP and spatial memory. Likewise, adenosine deaminase, which converts adenosine into the inactive metabolite inosine, restored impaired hippocampal CA1 LTP. We further found that adenosine accumulation was attributable to the alteration of adenosine uptake but not adenosine metabolisms. Bidirectional nucleoside transporters (ENT2) appeared to play a key role in the reduction of adenosine uptake. Changes in PKC-alpha/beta activity were correlated with the attenuation of the ENT2 function in the short-term (2 h) but not in the long-term (7 d) period after the termination of morphine treatment. This study reveals a potential mechanism by which chronic exposure to morphine leads to impairment of both hippocampal LTP and spatial memory.

Mechanism study on the frequent variations of cell-bound microcystins in cyanobacterial blooms in Lake Taihu: Implications for water quality monitoring and assessments

Although Microcystis-based toxins have been intensively studied, previous studies using laboratory cultures of Microcystis strains are difficult to explain the phenomenon that microcystin concentrations and toxin variants in natural blooms differ widely and frequently within a short-term period. The present study was designed to unravel the mechanisms for the frequent variations of intracellular toxins related to the differences in cyanobacterial colonies during bloom seasons in Lake Taihu, China. Monitoring of Microcystis colonies during warm seasons indicated that the variations in microcystins in both concentrations and toxin species were associated with the frequent alteration of Microcystis colonies in Lake Taihu. High concentration of microcystins in the blooms was always associated with two Microcystis colonies, Microcystis flos-aquae and Microcystis aeruginosa, whereas when Microcystis wesenbergii was the dominant colonial type, the toxin production of the blooms was low. Additionally, environmental factors such as temperature and nutrition were also shown to have an effect on the toxin production of the blooms, and may also potentially influence the Microcystis species present. The results of the present study provides insight into a new consideration for quick water quality monitoring, assessment and risk alert in cyanobacterium- and toxin-contaminated freshwaters, which will be beneficial not only for water agencies but also for public health. (C) 2009 Elsevier Ltd. All rights reserved.

The effect of cyanobacterial crude extract on the transcription of GST mu, GST kappa and GST rho in different organs of goldfish (Carassius auratus)

The glutathione S-transferases play important roles in the detoxification of microcystin. Core-sequences of three classes of GST (mu, kappa and rho) were cloned from goldfish (Carassius auratus L) i.p. injected with cyanobacterial crude extract at two doses (50 and 200 mu g MC-LReq kg(-1) BW). The relative changes of the mRNA abundance in liver, kidney and intestine were analyzed by real-time PCR. The transcription of GST mu was inhibited in intestine at both doses and the transcription of GST kappa was inhibited from 12 to 48 h in kidney at both doses. The decreased transcription of GST rho was detected in all three organs at the high dose. It is suggested that transcription inhibition of GST rho might be significant in MCs toxicity at higher toxin concentration in omnivorous freshwater fish. Alteration in transcription of GSTs stimulated by MCs implicates an increased health risk to fish. (C) 2008 Published by Elsevier B.V.

Mitochondrion-mediated apoptosis induced by Rana grylio virus infection in fish cells

A fish cell line, fathead minnow (FHM) cell, was used to investigate the alteration of mitochondrial dynamics and the mechanism of apoptosis under Rana grylio virus (RGV) infection. Microscopy observations, flow-cytometry analysis and molecular marker detection revealed the apoptotic fate of the RGV-infected cells. Some typical apoptotic characteristics, such as chromatin condensation, DNA fragmentation and mitochondrial fragmentation, were observed, and significantly morphological changes of mitochondria, including size, shape, internal structure and distribution, were revealed. The mitochondria in RGV-infected cells were aggregated around the viromatrix, and the aggregation could be blocked by colchicine. Moreover, the Delta psi m collapse was induced, and caspase-9 and caspase-3 were activated in the RGV-infected cells. In addition, NF-kappa B activation and intracellular Ca2+ increase were also detected at different times after infection. The data revealed the detailed dynamics of mitochondrion-mediated apoptosis induced by an iridovirus, and provided the first report on mitochondrial fragmentation during virus-induced apoptosis in fish cells.

Hematological and plasma biochemical responses of crucian carp (Carassius auratus) to intraperitoneal injection of extracted microcystins with the possible mechanisms of anemia

Alterations in hematological indices such as decreases in blood cell counts (RBC), hematocrit (Ht) and hemoglobin (Hb) concentrations are key symptoms of anemia. However, few experiments were conducted to examine changes in hematological indices of fish exposed to microcystins that are believed to be fatal to circulatory systems of vertebrates. An acute toxicological experiment was designed to study hematological changes of crucian carp injected intraperitoneally (i.p.) with extracted microcystins at two doses, 50 and 200 mu g MC-LReqkg(-1) body weight. After being i.p. injected with microcystins, the fish exhibited behavioral abnormity. There were significant decreases in RBC in the high-dose group, and in Ht and Hb concentrations in both dose groups, while erythrocte sedimentation rate (ESR) significantly increased, indicating the appearance of normocytic anemia. There were no prominent changes in the three red cell indices, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH,), and mean corpuscular hemoglobin concentration (MCHC). Increases in blood urea nitrogen (BUN) and creatinine (CR) in both dose groups suggest the occurrence of kidney impairment. Alteration in blood indices was reversible at the low dose group. Conclusively, anemia induced by kidney impairment was a key factor to cause abnormity of swimming behaviors and high mortality of crucian carp. (c) 2007 Elsevier Ltd. All rights reserved.

Post-impoundment biomass and composition of phytoplankton in the Yangtze River

Damming, and thus alteration of stream flow, promotes higher phytoplankton populations and encourages algal blooms (density > 10(6) cells L-1) in the Three Gorges Reservoir (TGR). Phytoplankton composition and biomass were studied in the Yangtze River from March 2004 to May 2005. 107 taxa were identified. Diatoms were the dominant group, followed by Chlorophyta and Cyanobacteria. In the Yangtze River, algal abundance varied from 3.13 x 10(3) to 3.83 x 10(6) cells L-1, and algal biomass was in the range of 0.06 to 659 mg C m(-3). Levels of nitrogen, phosphorus and silica did not show consistent longitudinal changes along the river and were not correlated with phytoplankton parameters. Phytoplankton abundance was negatively correlated with main channel discharge (Spearman r = -1.000, P < 0.01). Phytoplankton abundance and biomass in the Yangtze River are mainly determined by the hydrological conditions rather than by nutrient concentrations.

The Chinese rare minnow (Gobiocypris rarus) as an in vivo model for endocrine disruption in freshwater teleosts: a full life-cycle test with diethylstilbestrol

Chinese rare minnow (Gobiocypris rarus), a freshwater teleost,. was exposed to diethylstilbestrol (DES) at 0.05, 0.5, 1 and 5 mug/L from fertilized eggs for up to mature period under flow-through condition. Several endpoints that related to development, reproductive fitness and transgenerational effects were evaluated. It was found that body length and body weight were significantly reduced and vitellogenin (Via) levels were significantly increased for fish exposed to DES. Histological examination showed that the sex ratios of F-0 fish skewed to female and about 2% of the fish exposed to 0.05 mug/L DES developed testes-ova. The reproductive success, as determined from data on egg production, was reduced in female fish exposed to 0.05, 0.5, 1 and 5 mug/L DES. The lowest-observed-effect concentrations (LOEC) for chances of sex ratios, reproductive success and histology alteration of F-0 are 0.05 mug/L. In the offspring, transgenerational effects on egg hatching rate. egg fertilization and Vtg levels of juvenile individuals were not observed. However. survival of F, generation fry significantly declined. The analysis of sex steroid levels revealed a significant decrease of testosterone (T) in the whole body homogenates (WBH) of male progeny and somewhat elevation of estradiol (E-T) in the WBH of female offspring. These findings indicate that exposure to DES causes a variety of developmental, reproductive and transgenerational effects. (C) 2004 Elsevier B.V. All rights reserved.

Broad host range plasmid-based gene transfer system in the cyanobacterium Gloeobacter violaceus which lacks thylakoids

Gloeobacter violaceus, a cyanobacterium lack of thylakoids, is refractory to genetic manipulations because its cells are enveloped by a thick gelatinous sheath and in colonial form. In this study, a large number of single cells were obtained by repeated pumping with a syringe with the gelatinous sheath removed. And an exogenous broad host range plasmid pKT210 was conjugatively transferred into G. violaceus. Analyses with dot-blot hybridization and restriction mapping showed that the exogenous plasmid pKT210 had been introduced into G. violaceus and stably maintained with no alteration in its structure. pKT210 extracted from G. violaceus exconjugants could be transformed into the mcr - mrr - E. coli strain DH10B but not the mcr(+) mrr(+) strain DH5alpha, which suggests that a methylase system may be present in G. violaceus.

Effects of cell-cycle arrest agents on cleavage and development of loach (Misgurnus anguillicaudatus) embryos

The aim of this study was to determine the lowest concentration of nocodazole and colchicine to arrest blastomere division during the cleavage stage of loach embryos and to assess the reversibility and toxicity of the treatments in the treated embryos. Eight-cell loach embryos were incubated for 4, 8, 12, or 16 h in 1/10x Holtfreter supplemented with either nocodazole, an inhibitor of tubulin polymerization, or colchicine, an inhibitor of tubulin assembly. Complete arrest of cell cycle was observed, at a colchicine concentration of 0.996 mM and at a nocodazole concentration of 0.275 muM, respectively (the lowest effective concentration). No major morphological alteration in chromatin was observed. Reversibility and toxicity of both agents were dose and exposure period dependent. For both agents, prolonging cleavage arrest for more than 4 h (at the effective concentrations) is detrimental to development of embryos. Nocodazole treatment was less cytotoxic, whereas the concentrations of colchicine which induce cleavage arrest were detrimental to development beyond the blastula stage. Toxic effects beyond the blastula stage could be minimized for both agents by reducing the period of treatment and concentration.

The toxic effects of microcystin-LR on embryo-larval and juvenile development of loach, Misguruns mizolepis Gunthe

Microcystin-LR, a specific and potent hepatotoxin, was tested for its effects oil loach embryo-larval and juvenile development, The results of this study showed that loach embryos were more sensitive when exposed to microcystin-LR at a later than at an earlier stage of development, Juveniles were far less sensitive to MC-LR than were embryos and larvae. Mortality and developmental abnormality were proven to be dose-dependent and to be stage-specific sensitive. Among the abnormal changes noted were: pericardial edema and tubular heart, bradycardia, homeostasis, poor yolk resumption. small head, curved body and tail, and abnormal hatching, Liver and heart were the main targets of microcystin-LR toxicity. Ultrastructural analysis documented a complex set of sublethal effects of microcystin-LR on loach hepatocytes, chiefly including morphological alteration in nuclear and RER of loach liver cells. fit addition, microcystin-LR was lethal to loach juvenile in the subacute (7 days) exposure (LC50) = 593.3 mug/l). (C) 2002 Elsevier Science Ltd. All rights reserved.

Growth of c-oriented ZnO films on (001) SMO3 substrates by MOCVD

The growth direction of ZnO thin films grown by metal-organic chemical vapor deposition (MOCVD) is modulated by pretreatment of (001) SMO3 (STO) substrates. ZnO films show a-oriented smooth surface with epitaxial relationship of < 001 > ZnO//< 110 > STO on as-received SfO, and c-axis columnar growth with < 010 > ZnO//< 110 > STO on etched STO, respectively. The orientation alteration of ZnO films is supposed to be caused by the change of STO surface polarity. In addition, the c-ZnO films exhibit an enhanced photoluminescence (PL) intensity due to the improved crystal quality, while the blueshift of PL peak is attributed to the smaller tensile strain. These results show that high quality c-ZnO, which is essential for electronic and optoelectronic device applications, can be grown on (001) SfO by MOCVD. (C) 2008 Elsevier B.V. All rights reserved.

微生物法沥取重金属污泥中铬的研究

本文研究了两种微生物及其组合沥取、回收用微生物法治理电镀铬废水产生的铬污泥中的铬。铬污泥富含C、N、O，含铬量为13%， 经X-光电子能谱分析铬以三价态(氢氧化铬)存在。二种微生物分别从一酸性矿水和酸性污泥中分离筛选得到，经鉴定为硫杆菌属 (Thiobacillus Beijerinek)的两个不同种，一为氧化亚铁硫杆菌(Thiobacillu ferrooxidans, TF), 另一为氧化硫硫杆菌 (Thiobacillus thiooxidans, TT)。研究并比较了不同微生物对污泥中铬的沥取能力，结果表明，TT菌沥取铬效率最高。振荡、动 态淋滤、静置等沥取方式经过研究表明动态淋滤为最佳，室温条件下(15-20℃)，污泥浓度为20g/L时，总铬沥出率达60%时所需时 间：动态淋滤为48.5h，振荡和静置方式分别为91.22，81.6h。研究了不同温度、不同起始PH、不同污泥浓度及非成熟菌液对微生 物沥取能力的影响：(1) 沥取前期，温度对铬的沥出影响较大；微生物沥取反应基本属一级反应；温度与反应速率的关系基本符合 Arrhenius方程，但沥取后期这一特点并不突出。(2) 沥取液最适起始PH为菌液自然PH；PH值的人为改变将使铬的沥出大大降低。 (3) 污泥浓度与铬的沥出呈正相关，但浓度高于30g/L时，铬的沥出量不再增加。(4) 非成熟菌液沥出铬的能力较差，但沥取液中 微生物生长繁殖较为活跃。总结微生物沥取反应最佳沥取条件为：TT成熟菌液、污泥浓度10g/L、温度25-36℃、动态淋滤方式，此 时铬几乎可100%从污泥中沥出。经扫描电镜分析，沥取开始时，微生物紧密吸附于污泥颗粒表面上，表面紧密吸附为微生物发挥功 能提供了基础。微生物沥取污泥中铬的反应机理推测为：硫细菌代谢产硫酸或氧化Fe2+成Fe3+，利用酸，Fe3+ 及自身氧化酶系统 氧化污泥中Cr3+为Cr6+,Cr6+溶出结晶为CrO3。This paper has studied bioleaching and recovery of Chronium(Cr)from electroplating sludge by two consortum of bacteria and their combination, with sludge produced by microbiological process treating electroplating wastewater containing Cr as material. The share of Cr is 13% and its state is Cr (OH)3 in the sludge. One of the bacteria in the paper was isolated from acid sewage sludge and the other was from acid mineral water. The former was tested and determined as Thiobacillus ferroxidans(TF) and the latter was Thiobacillus thiooxidans(TT). Different microorganisms, responsible for the metal leaching activity, have great influence on the efficiency of leaching. The results showed that TT has biggest power. Experiments were conducted to examined effects of three different ways of leaching(Shaking, Down-leaching, Static-leaching). When temperature was in-door's (15-20℃)and concentration of the sludge was 20g/L, the bioleaching time required to reach 60% of Cr solubilization with the above three ways were 91.2, 48.5, 81.6h respectively. Down-leaching was proved to be the most efficient. The influence of different temperature, initial PH, concentration of the sludge and non-mature inoculum had been studied. The results obtained reveal that: (1) The variation of temperature is important during the time from initial to middle of leaching. The reaction of bioleaching belongs to first-order. The relation between the bioleaching rate constant(In k)and temerature can be expressed by Arrhenius function. (2) The fittest initial PH is the nature PH of mature inoculum. Any alteration with it could cause clearly negative effection. (3) The concentration of the sludge can make strong influence on the bioleaching efficiency. But when the concentration is above 30g/L, the increasing of Cr in the solution is little. (4) If non-mature inoculum acts as the bioleachin microorganism, little quantity of Cr would be gained from the sludge. But the micormass in the solution is very active. The results from electron microscope showed that microorganisms adhered to the surface of the sludge and the adherence was the first stage of the bioleaching. Some salts of Cr can be obtained afer the water of the bioleaching solution being evaporated. By analysing the results of experiment with X-Ray spectroscopy, the salt was identified as CrO3. The recovery rate of Cr is 78.4%.