入侵红藻真江蓠(Gracilaria vermiculophylla)和非入侵红藻绳状龙须菜(Gracilariopsis chorda)的比较转录组研究

红藻真江蓠(Gracilaria vermiculophylla)是西北太平洋地区特有种,但在过去100年间它借助海运(太平洋牡蛎养殖)快速入侵到北美、欧洲和地中海等沿海栖息地,对当地的生物多样性、海洋环境和生态系统等造成重大影响。为从分子水平初步了解真江蓠成功入侵的潜在机制,文章对其入侵起源地——日本北部的真江蓠及非入侵种——绳状龙须菜(Gracilariopsis chorda)进行了同质园实验(common garden experiment)处理后的比较转录组研究,以探究该地区入侵属性不同的两种红藻间的基因表达差异。结果表明,真江蓠和绳状龙须菜共有基因序列集(Universal Gene,unigene)主要集中在核糖体、嘌呤和嘧啶代谢等通路。其中,在真江蓠中光系统II反应中心蛋白D1(photosystem II reaction center protein D1)、细胞色素P450单加氧酶(cytochrome P450 monooxygenase)和核酮糖1,5二磷酸羧化酶大亚基(Ribulose bisphosphate carboxylase large subunit,rbcL)等基因的表达量显著上调,而逆转录转座子蛋白(retrotransposon protein)、细胞壁相关的水解酶(cell wall-associated hydrolase)和金属离子转运蛋白Nramp5的表达既上调也下调。与光合作用过程相关基因的大量表达可能有助于真江蓠应对逆境胁迫,特别是光系统ⅡD1反应中心蛋白表达量升高可能有助于藻体修复光系统Ⅱ复合体,从而制造更多的有机物以备藻体生长所需。而金属离子转运蛋白Nramp5等的上调和下调则表明江蓠等红藻可能通过某些基因表达量的增减对不同的环境变动作出响应。总体而言,代谢过程中的资源再分配很可能是驱动真江蓠适应和耐受新的生境的主要分子机制。

In situ Colonization of Marine Biofilms on UNS S32760 Duplex Stainless Steel Coupons in Areas with Different Water Qualities： Implications for Corrosion Potential Behavior

In the presence of biofilms, stainless steels （SS） exhibits an increase in corrosion potential, called ennoblement. In the present study, the corrosion potential （Eco,） behavior of the duplex SS UNS S32760 was recorded simultaneously with the in situ marine biofilm formation in two areas at Arraial do Cabo, Southeastern Brazil. The biofilm at Forno Harbor （an anthropogenically disturbed area） was characterized by higher relative abundances of Bacteria at day 2, followed by diatoms （especially Navicula sp.） on day 10 and dinoflagellates on day 18, whereas no clear trend was recorded at Cabo Frio Island （an undisturbed area）. The ennoblement of Ecor values was site-dependent. In a complementary laboratory assay, biofilms were removed and the Eco values registered in sterile conditions for the subsequent 10 days and corroborated in situ results. Understanding biofilms and SS interactions has important implications for materials science and engineering decisions as well as helping to fill in imnortant gaps in this knowledge.

Biofilm Formation by Marine Cobetia marina alex and Pseudoaltero­monas spp: Development and Detection of Quorum Sensing N-Acyl Homoserine Lactones (AHLs) Molecules

Surfaces submerged in seawater are colonized by various microorganisms,resulting in the formation of heterogenic marine biofilms.This work aims to evaluate the biofilm formation by Cobetia marina alex and doing a comparative study between this promising strain with the two bacterial strains isolated previously from the Mediterranean seawater,Alexandria,Egypt.Three strains;Cobetia marina alex,Pseudoalteromonas sp.alex,and Pseudoalteromonas prydzensis alex were screened for biofilm formation using the crystal violet(CV)quantification method in a single culture.The values of biofilm formed were OD600=3.0,2.7,and 2.6,respectively leading to their selection for further evaluation.However,factors affecting biofilm formation by C.marina alex were investigated.Biofilm formation was evaluated in single and multispecies consortia.Synergistic and antagonistic interactions proved in this work lead to the belief that these bacteria have the capability to produce some interesting signal molecules N-acyl Homoserine Lactones(AHLs).

Assessment of Secondary Metabolites from Marine-Derived Fungi as Antioxidant

Marine derived fungi are considered as a promising source of novel drugs due to their biodiversity and consequent chemo-diversity. Although marine microorganisms especially fungi are not well defined taxonomically, making this a promising frontier for the discovery of new medicines. This study focused on marine derived fungi as a model for bioactive exploration for new entities with anti-inflammatory and antioxidant capacity. Three in-vitro assays were used to investigate the bioactive antioxidant potentiality of fungal extracts. Thiobarbituric acid (TBARS),α,α-Diphenyl-β- picrylhydrazyl (DPPH) and NO assay are based on their total phenolic and flavonoid content of each extract group. Ch. globosum recorded the highest antioxidant activity (92.82%) in TBARS assay, while G. dankaliensis came first by recording 59.28% in DPPH assay in comparison with ascorbic acid (61.83%). In NO inhibition assay, N. oryzae showed 49.3% comparing with ascorbic acid (73.12%). From the preliminary result of our extracts, we can consider the marine derived fungi extracts as promising antioxidant and anti-inflammatory drug candidate.

Agarase Production by Marine Pseudoalteromonas sp.MHS:Optimization,and Purification

Agar is an essential polysaccharide that has been utilized in numerous fields.Many kinds of literature have been published regarding agarolytic microorganisms’isolation and agarases biochemical studies.In this search,a local marine agarolytic bacterium associated with marine alga Ulva lactuca surface was isolated and identified as Pseudoalteromonas sp.MHS.The agarase production was parallel to the growth of Pseudoalteromonas sp.MHS as cells displayed a lag phase(2 h),subsequently an exponential growth that prolonged till 10 h where maximum growth(OD550nm=3.9)was achieved.The enzyme activity increased rapidly as cells increased exponentially where the maximum activity of 0.22 U/mL was achieved after 8h and remained constant till 12 h during the stationary phase of growth.Agarase production was optimized using Plackett-Burman statistical design by measuring enzyme activity as a response and the design was validated using a verification experiment;the activity of the enzyme increased from 0.22 U/mL to 0.29 U/mL.Pseudoalteromonas sp.MHS agarase was partially purified and its molecular weight(MW)was determined by SDS-PAGE(15-25 kDa).Agarase showed approximately 94% of its activity at 40℃.The enzyme stability decreased as the temperature increased;the enzyme could retain about 98,90,80,75,and 60% of its activity at 20,30,40,50,and 60℃,respectively.Biomass of the red alga Pterocladia capillacea proved to be a suitable substrate for agarase production using Pseudoalteromonas sp.MHS;the enzyme activity recorded after 24 h of incubation was 0.35 U/mL compared to 0.29 U/mL from the optimized medium.

Autosub6000:A Deep Diving Long Range AUV

With an ultimate range up to 1000 km,a maximum operating depth of 6000 m,and a generous payload capacity,Autosub6000 is well placed to become one of the world's most capable deep diving Autonomous Underwater Vehicles(AUVs). Recently,Autosub6000 successfully completed its first deep water engineering trials,and in September 2008,fitted with a multibeam sonar,will carry out its first science missions.This paper will describe how we are tackling the design issues that specifically affect a deep diving AUV which must be capable of operating with true autonomy,independently of the mother ship, namely:carrying adequate energy for long endurance and range,coping with varying buoyancy,and maintaining accurate navigation throughout missions lasting up to several days.Results from the recent engineering trails are presented,and future missions and development plans are discussed.

Assessing the benthic quality status of the Bohai Bay(China)with proposed modifications of M-AMBI

Multivariate AZTI＇s Marine Biotic Index （M-AMBI） was designed to indicate the ecological status of European coastal areas. Based upon samples collected from 2009 to 2012 in the Bohai Bay, we have tested the response of variations of M-AMBI, using biomass （M-BAMBI） in the calculations, with different transformations of the raw data. The results showed that the ecological quality of most areas in the study indicated by M-AMBI was from moderate to bad status with the worse status in the coastal areas, especially around the estuaries, harbors and ouffalls, and better status in the offshore areas except the area close to oil platforms or disposal sites. Despite large variations in nature of the input data, all variations of M-AMBI gave similar spatial and temporal distribution patterns of the ecological status within the bay, and showed high correlation between them. The agreement of new ecological status obtained from all M-AMBI variations, which were calculated according to linear regression, was almost perfect. The benthic quality, assessed using different input data, could be related to human pressures in the bay, such as water discharges, land reclamation, dredged sediment and drilling cuts disposal sites. It seems that M-BAMBI were more effective than M-NABMI （M-AMBI calculated using abundance data） in indicating human pressures of the Bay. Finally, indices calculated with more severe transformations, such as presence/absence data, could not indicate the higher density of human pressures in the coastal areas of the north part of our study area, but those calculated using mild transformation （i.e., square root） did.

Evaluation of phenolic contents and antioxidant activities of brown seaweeds belonging to Turbinaria spp.(Phaeophyta,Sargassaceae) collected from Gulf of Mannar

Objective:To evaluate the antioxidant activities and total phenolic contents of brown seaweeds belonging to Turbinaria spp.[Turbinaria conoides(T.conoides)and Turbinaria ornata(T.ornata)collected from Gulf of Mannar of southeastern coast of India in various in vitro systems.Methods:The antioxidant activity was evaluated using different in vitro systems,viz.,I,I-diphenyl-2-picrylhydrazyl(DPPH),2,2'-azino-bis-3 ethylbenzothiozoline-6-sulfonic acid diammonium salt(ABTS),H_20_2/H0 radical scavenging,Fe^(2+)ion chelating ability,and reducing potential.Folin-Ciocalteu method was used to determine the total phenolic content of the extracts,and the results were expressed as mg of gallic acid equivalents(GE)/g of the seaweed extracts.Thiobarbituric acid-reactive substances assay was employed to assess the ability of the seaweed extracts to inhibit lipid oxidation.Results:Ethyl acetate(EtOAc)fraction of T.conoides registered significantly higher phenolic content(105.97 mg GE/g)than that of T.ornata(69.63 mg GE/g).Significantly higher antioxidant potential as determined by DPPH(64.14%)radical scavenging activity was registered in EtOAc fraction of T.ornata.A higher ABTS(?)radical scavenging(IC_(50)3.16μg/mL),Fe^(2+)chelating(IC_(50)0.46 mg/mL),H_2O_2 scavenging(IC_(50)4.25 mg/mL),lipid peroxidation inhibitory(TBARS,IC_(50)0.21 mg/mL),and reducing abilities(IC_(50)52.67 mg/mL)(P<0.05)were realized in EtOAc fraction of T.ornata than other fractions.Conclusions:This study indicated the potential use of T.conoides and T.ornata as candidate species to be used as food supplements/functional foods to increase shelf-life of food items for human consumption,and nutraceuticals to deter deleterious free radical-induced life-threatening diseases.

Lithofacies modeling by multipoint statistics and economic evaluation by NPV volume for the early Cretaceous Wabiskaw Member in Athabasca oilsands area, Canada

The static modeling and dynamic simulation are essential and critical processes in petroleum exploration and development. In this study, lithofacies models for Wabiskaw Member in Athabasca, Canada are generated by multipoint statistics(MPS) and then compared with the models built by sequential indicator simulation(SIS). Three training images(Tls) are selected from modern depositional environments;the Orinoco River Delta estuary, Cobequid bay-Salmon River estuary, and Danube River delta environment. In order to validate lithofacies models, average and variance of similarity in lithofacies are calculated through random and zonal blind-well tests.In random six-blind-well test, similarity average of MPS models is higher than that of SIS model. The Salmon MPS model closely resembles facies pattern of Wabiskaw Member in subsurface. Zonal blind-well tests show that successful lithofacies modeling for transitional depositional setting requires additional or proper zonation information on horizontal variation, vertical proportion, and secondary data.As Wabiskaw Member is frontier oilsands lease, it is impossible to evaluate the economics from production data or dynamic simulation. In this study, a dynamic steam assisted gravity drainage(SAGD)performance indicator(SPIDER) on the basis of reservoir characteristics is calculated to build 3 D reservoir model for the evaluation of the SAGD feasibility in Wabiskaw Member. SPIDER depends on reservoir properties, economic limit of steam-oil ratio, and bitumen price. Reservoir properties like porosity,permeability, and water saturation are measured from 13 cores and calculated from 201 well-logs. Three dimensional volumes of reservoir properties are constructed mostly based on relationships among properties. Finally, net present value(NPV) volume can be built by equation relating NPV and SPIDER. The economic area exceeding criterion of US$ 10,000 is identified, and the ranges of reservoir properties are estimated. NPV-volume-generation workflow from reservoir parameter to static model provides costand time-effective method to evaluate the oilsands SAGD project.

Antifouling evaluation of extracts from Red Sea soft corals against primary biofilm and biofouling

Objectives: To evaluate antifouling property of extracts from Red Sea soft corals against primary biofilm and biofouling.Methods: Seven species of soft corals Sarcophyton glaucum(a), Sinularia compressa,Sinularia cruciata(a), Heteroxenia fuscescens(a), Sarcophyton glaucum(b), Heteroxenia fuscescens(b) and Sinularia cruciata(b) were chosen to test their extracts as antibacterial and antifouling agents in Eastern Harbour of Alexandria, Mediterranean Sea.Bioactive compounds of soft corals were extracted by using methanol and concentrated under vacuum. The residues of extracts were mixed in formulation of inert paint which consisted of rosin, chlorinated rubber and ferrous oxide against micro and macro fouling organisms. The formulated paints were then applied on PVC panels twice by brush,hanged in a steel frame and immersed in Eastern Harbour of Alexandria Mediterranean Sea followed by visual inspection and photographic recordings.Results: After 185 days of immersion in seawater, the antifouling results agreed with the antibacterial results where extracts of Sinularia compressa and Heteroxenia fuscescens(b) gave the best activity against marine fouling tubeworms and barnacles. The inhibition activity was correlated with the major functional groups(hydroxyl, amino, carbonyl,aliphatic(fatty acids), C]C of alkene or aromatic rings and CeC l of aryl halides) of the extracts.Conclusions: The strong antifouling activity makes them promising candidates for new antifouling additives. After the screening and application of natural organic compounds from soft corals, marine organisms show activity against micro and macro fouling organisms.

Efficient Extraction of Agarose from Red Algae Using Ionic Liquids

We explored the possibility of using ionic liquids (ILs) as medium for efficient extraction of agarose via dissolution of red algae under varying conditions of heating or microwave irradiation. As compared to conventional methods, a very high extraction yield of good quality agarose (as high as 39 wt%) could be achieved depending upon the nature of used IL and applied experimental conditions. Purity of extracted agarose was confirmed from various spectral and analytical techniques, such as 1H and 13C NMR, FTIR, circular dichroism (CD), gel permeation chromatography (GPC) and thermogravimetric analysis (TGA). The physicochemical properties, such as gelling or melting temperature, viscosity and gel strength of extracted agarose hydrogels have been measured and compared with the agarose obtained from similar source reported in the literature. ILs were recovered after the extraction of agarose and were reused for further extraction experiments. % Recycling and extraction ability of recycled ILs in different cycles have been measured. The developed extraction process of utilizing ILs as medium is easy, simple and highly efficient as compared to the conventional methods of agarose extraction from algae.

Iterative static modeling of channelized reservoirs using history-matched facies probability data and rejection of training image

Most inverse reservoir modeling techniques require many forward simulations, and the posterior models cannot preserve geological features of prior models. This study proposes an iterative static modeling approach that utilizes dynamic data for rejecting an unsuitable training image(TI) among a set of TI candidates and for synthesizing history-matched pseudo-soft data. The proposed method is applied to two cases of channelized reservoirs, which have uncertainty in channel geometry such as direction, amplitude, and width. Distance-based clustering is applied to the initial models in total to select the qualified models efficiently. The mean of the qualified models is employed as a history-matched facies probability map in the next iteration of static models. Also, the most plausible TI is determined among TI candidates by rejecting other TIs during the iteration. The posterior models of the proposed method outperform updated models of ensemble Kalman filter(EnKF) and ensemble smoother(ES) because they describe the true facies connectivity with bimodal distribution and predict oil and water production with a reasonable range of uncertainty. In terms of simulation time, it requires 30 times of forward simulation in history matching, while the EnKF and ES need 9000 times and 200 times, respectively.

Parameterization and Application of Storm Surge/Tide Modeling Using a Genetic Algorithm for Typhoon Periods

A genetic algorithm was used to optimize the parameters of the two-dimensional Storm Surge/Tide Operational Model （STORM） to improve sea level predictions.The genetic algorithm was applied to nine typhoons that affected the Korean Peninsula during 2005-2007.The following model parameters were used：the bottom drag coefficient,the background horizontal diffusivity,Smagorinski＇s horizontal viscosity,and the sea level pressure scaling.Generally,the simulation results using the optimized,mean,and median parameter values improved sea level predictions.The four estimated parameters improved the sea level prediction by 76% and 54% in the bias and root mean square error for Typhoon Kalmaegi （0807） in 2008,respectively.One-month simulations of February and August 2008 were also improved using the estimated parameters.This study demonstrates that parameter optimization on STORM can improve sea level prediction.

Characterization of some bacterial strains isolated from the Egyptian eastern and northern coastlines with antimicrobial activity of Bacillus zhangzhouensis OMER4

Marine microorganisms were considered to be important sources of marine bioactive compounds.The major objective of the study was to isolate and characterize bacteria with antimicrobial activities from the various marine environment of Egypt.In this respect,thirty-five bacterial isolates were recovered from sediment samples collected from different spots along the Egyptian Red Sea coastline and Alexandria coastline during the summer season of 2017 and 2018.According to the morphological,physiological,and biochemical characteristics,the bacterial isolates were clustered into 13 groups designated as A,B,…,M.And,14 Gram-negative and 21 Grampositive bacteria were determined.The isolated bacterial strains were screened for their potentiality for antimicrobial agent(s)production against ten indicator strains.Strain Mo13 was showed high antimicrobial activity against all empirical strains.Subsequently,the most promising marine bacterial isolate with code MO13 was identified as Bacillus zhangzhouensis OMER4 according to the phenotypic characterization through morphological,physiological,and biochemical tests as well as genotypic characterization through the 16 S rDNA technique.The bioactive components were extracted with ethyl acetate,then analyzed using GC-MS and the substantial component was recognized as phenol,2,4-bis(1,1-dimethyl ethyl).

High Resolution Regional and Coastal Operational Storm Surges/Tide Forecasting System in Korea

This study was performed to compare storm surges/tide simulated by the regional and coastal storm surges/tide forecast system （RTSM （regional tide/storm surges model）, CTSM （coastal tide/storm surges model）） using two different inputs from weather models （RDAPS （Regional Data Assimilation and Prediction System） and KWRF （Korea Weather and Research Forecasting）） during two typhoons that occurred between 2007 and 2008. Both the RDAPS and KWRF are the operational weather forecasting system in KMA （Korea Meteorological Administration）. The horizontal resolutions of RDAPS and KWRF are 30 and 10 km, respectively. The storm surges/tide was hind casted using sea wind and pressure fields of two Typhoons which was approaching Korean Peninsula. The CTSM using input from KWRF simulate very well the storm surges/tide pattern in the complex coastal areas. The result showed that the storm surges by the coastal storm surges/tide model with high resolution input was in well agreement with the observed sea level occurred by high tide and storm surges in the coastal areas.

Status,structure and environmental variations in semi-arid mangroves of India

The semi-arid mangroves of the Gulf of Kachchh,the largest ecosystems on the west coast of India,are poorly studied in terms of vegetation structure and environmental parameters in spite of their conservation significance.Therefore,it is necessary to document the structural features of these mangroves in view of ongoing coastal industrial development.Mangrove forest structure in 10 locations on the northern and southern coasts of the Gulf of Kachchh were assessed using the line intercept transect method.Descriptions included density of young and mature age classes,tree heights,diameters at breast height(DBH)and aboveground biomass,along with seven significant environmental variables.Mature tree densities ranged from 350 to 1567 ind.ha-1,while average height and girth at breast height ranged from 1.0 to 6.8 m and 3.0 to 137.0 cm,respectively.The majority of trees(55.6%)were in B 1.8 m height class followed by a 1.9 to 2.4 m class(25.1%).DBH was most often in class 2 cm or lower than that.Among the canopy index classes,more trees were recorded in class ≤2 cm.The regeneration density was greater than the recruitment class.This study indicates that the poor structural attributes of Avicennia marina Vierth.var.acutissima Stapf and Mold dominated mangroves are largely due to aridity induced by scarce and erratic rainfall and high soil and water salinities.The results should be valuable in conserving and sustainably managing these mangroves in the face of developmental activities.

Concentrations of Poorly Studied Technology-Critical Elements Ge, Zr, Mo, Sn, Sb, Hf, Ta, W and Ti in the Sediments of Three Northern Egyptian Lakes

Thirty five Sediment samples were collected from three Northern Egyptian Lakes namely El Burullus, El Manzala and El Bardawil to evaluate for the first time the concentrations of poorly studied technology-critical elements, namely Ge, Zr, Mo, Sn, Sb, Hf, Ta, W and Ti, and how that may be linked to local water quality parameters and other geochemical factors. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was used to determine element’s concentration. The results were compared with Upper Continental Crust (UCC) and Nile sediment (ANS). Lake sediments generally have relatively low contents of most elements. The average concentration of Zr, Hf, Ta and W are lower than UCC and ANS in three Lakes. El Bardawil Lake attained the lowest average concentration for all elements except Mo. Correlation analysis revealed that water quality and geochemical properties did not play any important role affecting the metal distribution and the studied metals are generally not affected by the complex lacustrine system of these lakes and their spatial distribution still not affected by the different anthropogenic activates.

Global parameter estimation of the Cochlodinium polykrikoides model using bioassay data

Cochlodinium polykrikoides is a notoriously harmful algal species that inflicts severe damage on the aquacultures of the coastal seas of Korea and Japan. Information on their expected movement tracks and boundaries of influence is very useful and important for the effective establishment of a reduction plan. In general, the information is supported by a red-tide（a.k.a algal bloom） model. The performance of the model is highly dependent on the accuracy of parameters, which are the coefficients of functions approximating the biological growth and loss patterns of the C. polykrikoides. These parameters have been estimated using the bioassay data composed of growth-limiting factor and net growth rate value pairs. In the case of the C. polykrikoides, the parameters are different from each other in accordance with the used data because the bioassay data are sufficient compared to the other algal species. The parameters estimated by one specific dataset can be viewed as locally-optimized because they are adjusted only by that dataset. In cases where the other one data set is used, the estimation error might be considerable. In this study, the parameters are estimated by all available data sets without the use of only one specific data set and thus can be considered globally optimized. The cost function for the optimization is defined as the integrated mean squared estimation error, i.e., the difference between the values of the experimental and estimated rates. Based on quantitative error analysis, the root-mean squared errors of the global parameters show smaller values, approximately 25%–50%, than the values of the local parameters. In addition, bias is removed completely in the case of the globally estimated parameters. The parameter sets can be used as the reference default values of a red-tide model because they are optimal and representative. However, additional tuning of the parameters using the in-situ monitoring data is highly required.As opposed to the bioassay data, it is necessary because the bioassay data have limitations in terms of the in-situ coastal conditions.

Prestack Depth Migration by a Parallel 3D PSPI

Prestack depth migration for seismic reflection data is commonly used tool for imaging complex geological structures such as salt domes, faults, thrust belts, and stratigraphic structures. Phase shift plus interpolation (PSPI) algorithm is a useful tool to directly solve a wave equation and the results have natural properties of the wave equation. Amplitude and phase characteristics, in particular, are better preserved. The PSPI algorithm is widely used in hydrocarbon exploration because of its simplicity, efficiency, and reduced efforts for computation. However, meaningful depth image of 3D subsurface requires parallel computing to handle heavy computing time and great amount of input data. We implemented a parallelized version of 3D PSPI for prestack depth migration using Open-Multi-Processing (Open MP) library. We verified its performance through applications to 3D SEG/EAGE salt model with a small scale Linux cluster. Phase-shift was performed in the vertical and horizontal directions, respectively, and then interpolated at each node. This gave a single image gather according to shot gather. After summation of each single image gather, we got a 3D stacked image in the depth domain. The numerical model example shows good agree- ment with the original geological model.

Sulphated galactopyran derived fromGracilaria opuntia, a marine macroalgae restores the antioxidant metabolic enzymes during STZ induced diabetic rats

Objective:To screen the effect of sulphated galactopyran fraction isolated from Gracilaria opuntia (G. opuntia) (FM4) in streptozotocin (STZ) induced diabetic rats. Methods:In vitro antioxidant assays of FM4 were estimated byDPPH,ABTS, hydroxyl free radical and Nitric oxide free radical activities.FM4 was purified and characterized by1H-NMR spectra andFTIR as sulphated galactopyran. Diabetes was induced intraperitonially by single dose ofSTZ (55 mg/kg body weight).FM4 was administrated orally (80, 100, 125 mg/kgBW) to diabetic rats for 60 days. The enzymatic and non-enzymatic antioxidants such as superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), glutathione-S-transferase (GST), lipid peroxidase (LPx), glutathione reduced (GSH), vitamin-C (VIT-C) and vitamin-E (VIT-E) levels were estimated. Glibenclamide was used as standard drug. Results:Our results demonstrated that the aqueous extract ofG. opuntia possess free radical scavenging activity. During FM4 fraction treatment (100 mg/kgBW), theSOD,GPx,CAT,GST, GSH,VIT-C and VIT-E levels were significantly (P < 0.05) increased, and theLPx levels were decreased in different organs such as liver, kidney, brain and pancreas of diabetic rats. Conclusions: The sulphated galactopyran fraction of the marine macroalgae (G. opuntia) possesses the antioxidant activity which might help in the prevention of oxidative damage that occurs during diabetes.