共查询到19条相似文献,搜索用时 93 毫秒
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净化养殖水体紫色非硫光合细菌的筛选与鉴定 总被引:1,自引:0,他引:1
本研究从杭州养鱼塘水样及底泥样品中富集分离得到三株紫色非硫光合细菌,分别命名为HZ-3,HZ-4,HZ-5。 通过比较这三株菌对鱼、虾养殖水体的净化效果,筛选出菌株HZ-5 净化能力较强 ,经过5天的处理,该菌株使养鱼塘水样的COD 降低24.87%;使养虾池塘水样的COD 降低 36.99%;使养鱼塘水样的亚硝态氮的降解率达到97.79%。对菌株HZ-5进行了形态学观察、生理生化鉴定、活细胞吸收光谱以及16S rDNA序列分析。16S rDNA序列分析结果表明该菌株与沼泽红假单胞菌的16S rDNA序列有高达99%的同源性,结合形态特征和生理生化特性以及活细胞吸收光谱特征等,将其鉴定为沼泽红假单胞菌(Rhodopseudomonas palustris)。 相似文献
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紫色非硫细菌光合基因表达调控研究进展 总被引:4,自引:0,他引:4
紫色非硫细菌光合基因表达调控研究进展吴大庆,钱新民(山东大学微生物所,济南250100)紫色非硫细菌purplenonsulfurbacteria,以下简称PNS菌,即红螺菌科(Rhodosp-irillaceae),属于光合细菌的α和β亚门,具有较... 相似文献
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紫色非硫细菌质粒的制备与性质 总被引:2,自引:0,他引:2
介绍一种适于紫色非硫细菌质粒的制备方法,该法简单,易操作,质粒DNA纯度好,收率高,通过在加富培养基上连续传代数次,质粒DNA可自行消除。 相似文献
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[目的]系统阐述紫色非硫细菌(PNSB)砷代谢机制和砷代谢基因簇的进化关系.[方法]通过生物信息学方法分析了PNSB砷代谢基因簇的分布、组成、排布方式.采用UV-Vis和HPLC-ICP-MS方法,研究了3个PNSB种类对砷的抗性、砷形态及价态的转化、砷在细胞中的积累和分布以及磷酸盐对As细胞毒性的影响.[结果]砷基因簇分析表明:已公布全基因组序列的17个PNSB菌株基因组中均含有以ars operon为核心的砷代谢基因簇,由1-4个操纵子组成,主要含有与细胞质砷还原和砷甲基化代谢相关的基因,但基因的组成和排列方式因种和菌株而异,尤其是arsM和两类进化来源不同的arsC.实验结果表明:光照厌氧条件下,3个PNSB种类对As(V)和As(Ⅲ)均具有抗性,As(V)和As(Ⅲ)均能进入细胞 ;在胞内As(V)能够还原为As(Ⅲ)并被排出胞外,但不能将As(Ⅲ)氧化为As(V),也未检测到甲基砷化物 ;磷酸盐浓度升高,能够抑制As(V)进入细胞,降低As(V)对细胞的毒性,而不能抑制As(Ⅲ)进入细胞.[结论]PNSB砷代谢机制主体为细胞质As(V)还原,也还有砷甲基化途径.通过对砷代谢基因簇结构多样性特点和进化方式分析,提出了与Rosen不同的ars operon进化途径.这对深入开展PNSB砷代谢和基因之间的相互作用研究奠定基础. 相似文献
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光合细菌固定化及对养殖水净化的研究 总被引:9,自引:0,他引:9
采用海藻酸钠进行光合细菌固定化实验,比较了固定化菌和悬浮态菌的生长和生理特性,观察其在载体中的分布,并对其净化养殖水的能力进行初步研究。结果表明,固定化大大提高了光合细菌的生长速率;粒径为3.5mm,菌初始密度为0.12mg干菌泥/L为最佳固定化条件;在生长初期,菌在载体内的分布不均匀,后期趋于一致。在固定化菌净化养殖水的研究中发现,固定化光合细菌对养殖水的净化能力大大优于悬浮态菌。 相似文献
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【背景】中国是农业生产大国,渔林农牧占比庞大。有机农药无论在畜牧业还是水产养殖业都有广泛的应用。有机磷农药(Organophosphorus Pesticide,OP)是应用最广泛的有机农药,具有低毒和不易残留的优点。OP在水体中大量积累可通过生物富集作用间接影响人体健康,由此产生的生殖毒性不容忽视。光合细菌作为环境友好型水体有益菌,部分菌种具有降解有机农药的功能。【目的】自上海海洋大学明湖中分离纯化得到一株光合细菌(编号SPZ)。探究其对辛硫磷的耐受程度及降解效果,为养殖水体中有机磷农药的生物降解提供目的菌株。【方法】利用16S rRNA基因序列分析方法对目标菌株进行种属鉴定;利用紫外分光光度法测定分离菌株SPZ和标准菌株ST在不同接种量下的OD660并测定实验周期内光合细菌在不同浓度辛硫磷中OD660的变化趋势,以示辛硫磷对光合细菌的毒性作用;利用高效液相色谱法(High Performance Liquid Chromatography,HPLC)测定菌株对水体辛硫磷的降解能力;通过HPLC测定加热致死菌与活菌对水体辛硫磷的降解能力,确定菌株对辛硫磷的降解方式。【结果】16S r... 相似文献
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Purification of aquarium water by PVA gel-immobilized photosynthetic bacteria during goldfish rearing 总被引:1,自引:0,他引:1
Soo Kyong Jeong Jeong-Sup Cho In-Soo Kong Hyun Do Jeong Joong Kyun Kim 《Biotechnology and Bioprocess Engineering》2009,14(2):238-247
This study was conducted to evaluate the ability of a PVA-gel beads filtration (PVA) system using photosynthetic bacteria
to purify water. To accomplish this, duplicate long-term goldfish rearing experiments were conducted using four different
types of aquarium systems (COF, PSB, EMC, and PVA). The results revealed that the concentrations of NH4
+-N on the day of a goldfish’s death were significantly higher than the concentrations on other days for all the aquarium systems.
In addition, the mean concentration of NH4
+-N during goldfish rearing occurred in the following order: COF system > EMC system > PSB system > PVA system. Furthermore,
the mean values of all other ion concentrations (NO3
−-N, NO2
−-N, and PO4
2−-P) were found to be lowest in the PVA system. As a result, there was more prominent decomposition of organic matter in the
aquarium tank containing the PVA system, as well as less turbid aquarium water and more active goldfish. Additionally, the
PVA-gel beads resulted in almost complete denitrification, even after six-months of goldfish rearing. To our knowledge, this
is the first study to report that PVA gel-immobilized photosynthetic bacteria have the ability to purify water. Overall, the
results of this study indicate that this immobilized photosynthetic bacteria system has the potential for use as a component
in circulating filtration systems. 相似文献
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Alastair G. McEwan 《Antonie van Leeuwenhoek》1994,66(1-3):151-164
Purple non-sulfur phototrophic bacteria, exemplifed byRhodobacter capsulatus andRhodobacter sphaeroides, exhibit a remarkable versatility in their anaerobic metabolism. In these bacteria the photosynthetic apparatus, enzymes involved in CO2 fixation and pathways of anaerobic respiration are all induced upon a reduction in oxygen tension. Recently, there have been significant advances in the understanding of molecular properties of the photosynthetic apparatus and the control of the expression of genes involved in photosynthesis and CO2 fixation. In addition, anaerobic respiratory pathways have been characterised and their interaction with photosynthetic electron transport has been described. This review will survey these advances and will discuss the ways in which photosynthetic electron transport and oxidation-reduction processes are integrated during photoautotrophic and photoheterotrophic growth. 相似文献
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Pigment analysis was performed by means of normal phase HPLC on a number of bacteriochlorophyll a and b containing species of purple bacteria that contain a core antenna only. At least 99% of the bacteriochlorophyll in Rhodobacter sphaeroides R26, Rhodopseudomonas viridis and Thiocapsa pfennigii was esterified with phytol (BChl a
p and BChl b
p, respectively). Rhodospirillum rubrum contained only BChl a esterified with geranyl-geraniol (BChl a
GG). Rhodospirillum sodomense and Rhodopseudomonas marina contained, in addition to BChl a
p, small amounts of BChl a
GG, and presumably also of BChl a esterified with dihydro and tetrahydro geranyl-geraniol (2,10,14-phytatrienol and probably 2,14-phytadienol). In all species bacteriopheophytin (BPhe) esterified with phytol was present. The BChl/BPhe ratio indicated that in these species a constant number of 25 ± 3 antenna BChls is present per reaction centre. This number supports a model in which the core antenna consists of 12 - heterodimers surrounding the reaction centre. Determination of the in vivo extinction coefficient of BChl in the core-reaction centre complex yielded a value of ca. 140 mM–1 cm–1 for BChl a containing species and of 130 mM–1 cm–1 for Rhodopseudomonas viridis.Abbreviations BChl
bacteriochlorophyll
- BPhe
bacteriopheophytin
- GG
geranyl-geraniol
- LHI and LHII
core and peripheral antenna complexes
- P
phytol
- RC
reaction centre
Dedicated to the memory of Professor D.I. Arnon. 相似文献
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Role of HiPIP as electron donor to the RC-bound cytochrome in photosynthetic purple bacteria 总被引:2,自引:0,他引:2
Menin L. Gaillard J. Parot P. Schoepp B. Nitschke W. Verméglio A. 《Photosynthesis research》1998,55(2-3):343-348
High-Potential Iron-Sulfur Proteins (HiPIP) are small electron carriers, present only in species of photosynthetic purple bacteria having a RC-bound cytochrome. Their participation in the photo-induced cyclic electron transfer was recently established for Rubrivivax gelatinosus, Rhodocyclus tenuis and Rhodoferax fermentans (Schoepp et al. 1995; Hochkoeppler et al. 1996a, Menin et al. 1997b). To better understand the physiological role of HiPIP, we extended our study to other selected photosynthetic bacteria. The nature of the electron carrier in the photosynthetic pathway was investigated by recording light-induced absorption changes in intact cells. In addition, EPR measurements were made in whole cells and in membrane fragments in solution or dried immobilized, then illuminated at room temperature. Our results show that HiPIP plays an important role in the reduction of the photo-oxidized RC-bound cytochrome in the following species: Ectothiorhodospira vacuolata, Chromatium vinosum, Chromatium purpuratum and Rhodopila globiformis. In Rhodopseudomonas marina, the HiPIP is not photo-oxidizible in whole cells and in dried membranes, suggesting that this electron carrier is not involved in the photosynthetic pathway. In Ectothiorhodospira halophila, the photo-oxidized RC-bound cytochrome is reduced by a high midpoint potential cytochrome c, in agreement with midpoint potential values of the two iso-HiPIPs (+ 50 mV and + 120 mV) which are too low to be consistent with their participation in the photosynthetic cyclic electron transfer. 相似文献
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Alexander T. Eprintsev Marina I. Falaleeva Maya S. Lyashchenko Ilya Y. Toropygin 《Bioscience, biotechnology, and biochemistry》2018,82(1):81-89
Malate dehydrogenase (EC 1.1.1.37) was purified to homogeneity from the phototrophic purple non-sulfur bacterium Rhodovulum steppense A-20s. According to gel-chromatography and electrophoretic studies, malate dehydrogenase is present as a dimer, tetramer and octamer depending on cultivation conditions. In phototrophic aerobic conditions only the tetrameric form was present, in chemotrophic aerobic conditions all three forms were detected, while in the absence of oxygen the octameric form disappeared. The malate dehydrogenase oligomers are encoded by a single gene and composed of the same 35 kDa polypeptide but differ in pH and temperature optimum, in affinities to malate, oxaloacetate, NADH and NAD+ and in regulation by cations and citrate. By modulating the cultivation conditions, it has been established that the dimer participates in the glyoxylate cycle; the tetramer operates in the tricarboxylic acid cycle, and the octamer may be involved in the adaptation to oxidative stress. 相似文献
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水质净化乳酸菌的分离鉴定及发酵参数优化 总被引:1,自引:0,他引:1
【目的】从水产养殖环境和养殖生物体中选育具有水质净化功能的乳酸菌,以期为水产养殖提供专用高效的菌种资源。【方法】在低温和常温条件下从皮皮虾、南美白对虾肠道及养殖池底质活性污泥中分离具有水质净化功能的乳酸菌,对筛选的优良菌株采用形态、生理生化实验及16S r RNA序列分析进行鉴定,并对菌株的发酵参数进行了研究。【结果】低温和常温条件下从3种介质中共分离到乳酸菌136株,经水质净化能力筛选,发现常温分离的r13对模拟水体中亚硝态氮去除效果较强,72 h能将11.5 mg/L的亚硝态氮彻底去除,且对13.0 mg/L氨氮的去除率达到29.1%。经形态特征、生理生化特性及16S r RNA基因序列分析,鉴定菌株r13为植物乳杆菌Lactobacillus plantarum。发酵参数研究结果表明,该菌最适培养基组成为:酵母膏6.0 g/L,葡萄糖20.0 g/L,乙酸钠4.0 g/L,柠檬酸氢二铵2.0 g/L,K_2HPO_4 2.0 g/L,番茄汁50 m L/L;培养条件为:初始p H 6.0,接种量5%,装液量45/50,培养温度为34°C;在上述优化培养条件下发酵72 h,菌液的生物量达28.4 g/L湿重,有效活菌浓度达4.4×10~9 CFU/m L。 相似文献
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A serendipic observation at the Hopkins Marine Station of Stanford University in 1948 led to the discovery that anoxygenic photosynthetic bacteria can fix molecular nitrogen. To confirm the discovery, an unusual collaborative event was arranged between laboratories at Washington University (St. Louis) and the University of Wisconsin (Madison). 相似文献