Isolation,purification and characterization of the hydrogen evolution promoting factor of hydrogenase ofSpirulina platensis

A component (s-factor) with obvious promoting effect on hydrogen evolution of hydrogenase has been isolated and extracted from a cell-free preparation ofSpirulina platensis. The effect of the s-factor in the reaction system is similar to that of Na₂S₂O₄, but is coupled with light. The s-factor has the maximum absorption peak at 620 nm in the oxidized state, at 590 nm in the reduced state. The partially purified s-factor showed two bands by SDS-PAGE and is distinctly different from phycocyanin, which has no change of oxidized state and reduced state absorption spectra, and also has no promoting effect on hydrogenase ofSpirulina platensis under the light. The research supported by the NSFC.     

EFFECT OF GERMANIUM DIOXIDE ON GROWTH OF SPIRULINA PLATENSIS

This study on the effect of different concentrations of germanium dioxide (GeO_2) on the specificgrowth rate (SGR), pigment contents, protein content and amino acid composition of Spirulina platensisshowed that Ge was not the essential element of this alga; that GeO_2 could speed up growth and raiseprotein content of S. platensis, and could possibly influence the photosynthesis system. The concentrationrange of GeO_2 beneficial to growth of S. platensis is from 5-100 mg/l. GeO_2 is proposed to be util-ized to remove contamination by Chlorella spp. usually occurring in the cultivation of Spirulina.     

Bioaccumulation of Pb^2＋ and Its Effects on Growth, Morphology and Pigment Contents of Spirulina （Arthrospira）platensis

A laboratory experiment was conducted to assess the bioaccumulation of Pb2 and its effects on growth,morphology andpigment contents of Spirulina (Arthrospira) platensis.The specimen cultured in Zarrouk liquid medium was treated with variousinitial metal concentrations (0,5,10,30,50 and 100 μgmL-1).The growth of S.platensis was adversely affected by Pb2 at high con-centrations (30,50 and 100 μg mL-1).However,at low concentrations (5 μg mL-1),Pb2 could stimulate its growth slightly.The pig-ment contents (chlorophyll α and β carotene) were decreased in a dose-dependent manner.The highest reductions (67% and 53%respectively in chlorophyll α and β carotene) were observed in 100 μg mL-1 treatment group.The LC50 (96 h) of Pb2 was measured as75.34μg mL-1.Apart from a few cases of filament breakages at elevated concentrations (50 and 100μg mL-1),morphological abnor-malities are not specific.Metal bioaccumulation increased with Pb2 concentrations,but decreased with exposure time.The maxi-mum accumulated amount was 188 mgg-1 dry weight.The bioconcentration factor (BCF) reached to a peak at day 2,followed by agradual reduction for all the exposure concentrations.S.platensis is able to tolerate considerably high Pb2 concentrations.Conse-quently it can be used as a potential species to remove heavy metal from contaminated waters.     

Toxicity and Accumulation of Selenite in Four Microalgae

The toxicity and bioaccumulation of selenite in four microalgae, Spirulina platensis,Dunaliella salina, DunalieUa bardawill and Phaeodactylum tricornutum cultured in the presence of selenite were investigated. Lower concentrations of selenite were generally nontoxic and frequently stimulated algal growth, while higher concentrations of selenite inhibited algal growth. Selenite was more toxic to D. salina and D. bardawill than to S. platensis and P. tricornutum. All algae cultured in selenite were able to incorporate Se to different degrees, which depended on algal species. The distributions of selenite among intracellular macromolecular compounds were different among algal species : most of the selenite was associated with proteins in S. platensis, D. salina and D. bardawill, while most of the selenite was associated with lipids in P. tricornutum, which reflected the physiological differences among the algae. These observations suggest that algae are able to accumulate selenite and bind it with intracell~ar macromolecular compounds when exposed to high concentration of selenite. This may represent a form of storage or detoxification of selenite by the algae.     

Iron ions increase the thermostability of phycocyanin ofSpirulina maxima

A spectral method to investigate the effect of Fe³⁺, Fe²⁺ on the thermostability of phycocyanin (PC) ofSpirulina maxima showed that iron ions provent decrease of visible light absorbance and fluorescence intensity of PC. Increase in denaturation temperature caused by Fe³⁺ was observed by the micro-differential scanning calorimetric method. All results showed iron ions maintain the aggregation stability of the PC. The absorption spectrum of phycocyanobilin (PCB, a prosthetic group of PC) with Fe³⁺ in chloroform was quite different from that of free PCB.

     

螺旋藻制取叶绿素铜钠盐

用乙醇提取螺旋藻中的叶绿素,再用５％ＮａＯＨ溶液皂化、石油醚萃取,在酸性环境中用１０％ＣｕＳＯ４溶液实现铜镁置换,沉淀物经丙配溶解后,加２％ＮａＯＨ的乙醇溶液成盐,过滤,水洗,真空干燥,制成叶绿素铜钠盐．制品的质量达到ＧＢ３２６２－８２的要求．提取率为６４．７％,制品得率占藻粉１．１％。着重对铜镁置换的条件、制品耐酸、耐热、耐光等性能进行了对比试验,结果表明整个工艺是切实可行的．     

CHLOROPHYLL FLUORESCENCE RATIO F685/F735 IN BROWN ALGAE AND ITS VARIATION UNDER EXCITATION BY TWO TYPES OF LIGHT AND DEHYDRATION

Calculation and comparative study of the chlorophyll fluorescence ratio F685/F735 in brown algae (Laminaria japonica, Underia pinnatifida and Padina crassa) excited by blue and green light showed that the fluorescence ratios were higher when the algae were excited by blue light (440 nm), but reduced obviously under green light (540 nm) excitation. The values also reduced under dehydration but could recover during rehydration if the stress was not serious. The variation of the fluorescence ratio under dehydration was mainly because changes in fluorescence emission at 735 nm were always sharper than those at 685 nm. The ratio was sensitive to stress and has potential as a stress indicator in phycological research. Measurement of the fluorescence excitation spectra showed that the only peak at 540 hm changed apparently during dehydration. It meant that the function of the Chl a /Fucoxanthin protein complex for energy transfer was easily inhibited by water stress. However, no variation of the ratio was foun     

The isolation of prophyra-334 from marine algae and its UV-absorption behavior

1 INTRODUCTIONSolar ultraviolet radiation on the earth's surfaceincreases with the depletion of stratospheric ozone(Crutzen, 1992; Kerr and McElroy, 1993; Mad-ronich et al., 1998). Ultraviolet radiation is a highlyactive component of solar spectrum. The excessiveUV radiation has deleterious effects on all plant,animal and microbial groups exposed to solar radia-tion, including the destruction of DNA, proteins andother molecules (Harm, 1980), inhibition of photo-synthesis and growth (W…     

Study on Optical Properties of Unpigmented Suspended Particles,Yellow Substance and Phytoplankton Algae in Taihu Lake

The optical properties of a waterbody are subjects of research on limnological hydrooptics. The optical properties of, and parameterization methods for, three impurities in Taihu Lake, namely unpigmented suspensions, yellow substance and phytoplankton algae, are analyzed in detail in this paper dealing with the optical types of Taihu Lake waters both in winter and in summer. The results showed that : 1 ) The optical parameters of suspended particles can be calculated by the application of Mie Theory; 2) The absorption of yellow substance decreases exponentially with increasing wavelength, with the mean value of decreasing rate being about 0.014 nm^-1 ; 3) Taihu Lake waters appeared to be of type PY in winter, with suspended particles and yellow substance being the dominant light absorbers, and type CPY in summer, with suspended particles, yellow substance and phytoplankton algae being the dominant light absorbers; 4) In winter or summer, unpigmented suspension has the main effect on the scattering property of Taihu Lake waters.     

Solar radiation penetrating through sea ice under very low solar altitude

Based on the optical data for transmitted radiation through sea ice in the Arctic during the late autumn and early winter of 2007,the authors studied the arriving solar radiation,reflected radiation and transmitted radiation under very low solar altitude.Through the atmosphere,the light of the arriving solar radiation at short wavelength was weakened,with the spectral distribution of double peaks centered at 490 nm and 683 nm.The magnitude of the peak at 683 nm even exceeded that at 490 nm under the very low solar radiation condition.The reflection was lower than that in summertime because of the thin thicknesses of ice and snow,allowing higher ratio of heat to enter the sea ice and snow.When higher ratio of solar radiation entered sea ice in late autumn,the new ice freezing would be affected.The spectral reflectivity from snow surface was almost a constant,but the reflection without snow decreased at longer wavelengths.In the transmission spectrum,the light of 490nm was dominant.It indicates that the radiation at longer wavelength was weakened by sea ice.Therefore,under the condition of low solar altitude,the radiation at shorter wavelength was weakened by the atmosphere while the radiation at longer wavelength was weakened by the sea ice.The combined effect of atmosphere and sea ice made the solar radiation under sea ice much weaker.The absorption of sea ice for the longer-wavelength radiation allowed the sea ice to gain more heat to slow down the freezing process.     

Effects of spectral composition,photoperiod and light intensity on the gonadal development of Atlantic salmon Salmo salar in recirculating aquaculture systems (RAS)

Artificial lighting regimes have been successfully used to inhibit sexual maturity of Atlantic salmon in confinement.However,when these operations are applied in commercial recirculating aquaculture systems(RAS) using standard lighting technology,sexual maturation is not suppressed.In this study,an L_9(3~3) orthogonal design was used to determine the effects of three factors(spectral composition,photoperiod,and light intensity) on the gonadal development of Atlantic salmon in RAS.We demonstrated that the photoperiod at the tested levels had a much greater effect on the gonadosomatic index and female Fulton condition factor than spectral composition and light intensity.The photoperiod had a significant effect on the secretion of sex steroids and melatonin(P0.05),and a short photoperiod delayed sex steroid and melatonin level increases.The three test factors had no significant effects on the survival rate,specific growth rate,relative weight gain,and male Fulton condition factor(P0.05).The optimum lighting levels in female and male Atlantic salmon were LD 8:16,455 nm(or 625 nm),8.60 W/m~2;and LD 8:16,8.60 W/m~2,455 nm respectively.These conditions not only delayed gonadal development,but also had no negative effects on Atlantic salmon growth in RAS.These results demonstrate that a combination of spectral composition,photoperiod and light intensity is effective at delaying the gonadal development of both male and female salmon in RAS.     

The Anti-allergic Activity of Polyphenol Extracted from Five Marine Algae

Natural polyphenol has been widely believed to be effective in allergy remission. Currently, most of the natural polyphenol products come from terrestrial sources such as tea, grape seeds among others, and few polyphenols have been developed from algae for their anti-allergic activity. The aim of the study was to screen some commercial seaweed for natural extracts with anti-allergic activity. Five algae including Laminaria japonica, Porphyra sp., Spirulina platensis, Chlorella pyrenoidosa and Scytosiphon sp. were extracted with ethanol, and the extracts were evaluated for total polyphenol contents and anti-allergic activity with the hyaluronidase inhibition assay. Results showed that the total polyphenol contents in the ethanol extracts ranged from 1.67% to 8.47%, while the highest was found in the extract from Scytosiphon sp. Hyaluronidase inhibition assay showed that the extracts from Scytosiphon sp. had the lowest IC50, 0.67 mg m L-1, while Chlorella pyrenoidosa extract had the highest IC50, 15.07 mg m L-1. The anti-allergic activity of Scytosiphon sp. extract was even higher than the typical anti-allergic drug Disodium Cromoglycate(DSCG)(IC50 = 1.13 mg m L-1), and was similar with natural polyphenol from Epigallocatechin gallate(EGCG)(IC50 = 0.56 mg m L-1). These results indicated that the ethanol extract of Scytosiphon sp. contains a high concentration of polyphenol with high anti-allergic activity. Potentially Scytosiphon sp. can be developed to a natural anti-allergic compound for allergy remission.     

The effect of pH on both spectral types of R-phycoerythrin

There are two spectral types of R-phycoerythrin (RPE) in red algae. One is the triple peak type RPE with absorption maxima at 498,540 and 565 nm. The other is the double peak type RPE with absorption maxima at 498 and 565 nm, and an absorption shoulder at 540 nm. The former is present only in higher classes of the more advanced Florideophyceae, the latter occurs chiefly in the more primitive Bangiophyceae. When these two types of RPE are treated with buffer solutions with a broad pH range from 2.0 to 11.0, their absorption and fluorescence spectra remain unchanged within the range adjacent to neutral pH. At pH values higher than 9.6, the absorption and fluorescence spectra of triple peak type RPE still remain stable, but the absorption spectra of double peak type RPE produce gradually a protrusion similar to an absorption peak at about 540 nm. This phennomenon shows that there are certain differences in structure between these two types of RPE. Both types of RPE are naturally occurring products showing systematic developmental meaning in red algae. Contribution No. 1333 from the Institute of Oceanology, Academic Sinica.     

5种波长光对日本沼虾人工育苗幼体成活率的影响

光照与日本沼虾繁殖和孵化关系极为密切。研究了不同波长的光对日本沼虾孵化的影响 ,结果表明 :在环境光谱主峰值 4 70 .5nm、4 77.9nm、4 92 .6nm、5 0 4 .8nm和 6 15 .2nm条件下 ,适度成熟的亲虾都能顺利孵化 ,日本沼虾孵化与否 ,与孵化环境中的光波波长无关 ,而与抱卵日本沼虾胚胎发育有关。日本沼虾在孵化期对不同波长的光谱有明显的视觉敏感度分布 ,在前 4种光谱条件下 ,日本沼虾视觉器官敏感 ,而在光谱主峰值 6 15 .2nm时日本沼虾视觉器官不敏感。这一特点在日本沼虾育苗生产上具指导意义 ,可防止抱卵亲虾在孵化过程中吞食幼体 ,提高幼体成活率     

SELECTION OF BRILLOUIN SHIFT DISCRIMINATOR FOR BRILLOUIN LIDAR

For the measurement of vertical profiles of sound speed in the sea using laser excited Brillouin scattering, a high-resolution measurement of Brillouin frequency shift is required. In this work, a molecular absorption cell was selected as the frequency shift discriminator and several kinds of absorption gases were tried. It was found that the strong line ( # 1095) of ^127 I2 at 18783. 3297 cm^-1 and two absorption lines of ^129 I2 located at the two sides of the # 1095 line of ^127 I2 could be used as frequency shift discriminator to detect the changes of the Brillouin frequency shift. This selection is the best one within the range from 532.0131 run to 532.5154 nm. But it is not perfect and there is a lot of work to do before its practical application.     

PROMOTIVE EFFECT OF Se ON THE GROWTH AND ANTIOXIDATION OF A BLUE-GREEN ALGA SPIRULINA MAXIMA

ItwasreportedthatthegrOwthofthedrinediatomffelassforiraPsethenana(Hust.)HasleetHeiIndaldependedonSe(Priceetal.,1987).ThisreqUirementissPecificforSe;nootherelementscansubstituteforit,becauseSecaninduceglutathioneperoxidase(GSH-PoD)activityinthisdiatom(PriceandHarrison,l988),andinlow-CO2-grooCham~nasreinhandiiDangerad(Yokotaetal.,l988).ThisenZyInac-tivitywdetectedinextractsOfablue-greenalgaGleeoCaPasp.LB795(TotaandGallon,l979),andalsoincultUredhigherplancells(Drotaretal.,1985),butw…     

Isoenzymes and soluble protein in Arthrospirafrom alkaline lakes in Erdos Plateau, China and in exotic species

1 INTRODUCTION Since isoenzyme was first named by Markert and M?ller in 1957 (Hu and Wan, 1985), the separa- tion of isoenzyme has been rapidly developed. Isoenzymes is an important tool for studying life in molecule level. Isoenzymes are transcribed by g…     

负载型纳米TiO_2光催化杀灭溶藻弧菌的研究

采用平均粒径约5nm,主要结构为锐钛矿型的纳米TiO2光催化剂,以泡沫型复合镍板为载体对纳米TiO2进行固定,并对固定后的纳米TiO2杀灭溶藻弧菌的能力进行了研究。结果表明:利用高压汞灯作为光源,以泡沫型复合镍板为载体的纳米TiO2对溶藻弧菌具有较强的杀灭能力;极少量过氧化氢的加入加快了纳米TiO2的杀菌速度;因此,负载型纳米TiO2在水产病害防治方面具有广阔的应用前景。     

高泥质低品位氧化金矿提金方法研究

针对广西某氧化浸染型金矿的含金量低、含泥质高的特点，进行深入的提金试验研究。前人曾在矿山进行过工业规模的堆浸和池浸，均未达到预想效果，主要原因是未能解决好矿堆浸透性问题。试验通过优化制粒堆浸条件、应用滴淋布液技术等，大大地提高了矿堆浸透性能，最终获得了较满意的选别指标。试验结果说明只要采取有效措施，该矿石在生产现场用堆浸法提金还是可行的     

The Light Regime Effect on Triacylglycerol Accumulation of Isochrysis zhangjiangensis

Stress state of microalgal cells is caused under unfavorable conditions such as disordered light regime and depleted nitrogen. The stress state can impair photosynthetic efficiency, inhibit cell growth and result in the accumulation of triacylglycerol(TAG) from protective mechanisms. Continuous light or nitrogen starvation was applied on microalgae and performed effectively on inducing TAG production. To evaluate the light regime effect on inducing TAG production, the effect of different light regimes on nitrogen-starved Isochrysis zhangjiangensis was investigated in this work. The continuous light and nitrogen starvation elevated TAG content of biomass by 73% and 193%, respectively. Furthermore, the TAG accumulation of I. zhangjiangensis cell under nitrogen starvation decreased under aggravated stress from continuous illumination. Our results demonstrated that culturing the cells with 14 L: 10 D light regime under nitrogen starvation is the optimal mode to achieve maximal accumulation of TAG. A recovery in light regime was necessary for I. zhangjiangensis cultivation.