Spirogyra Neglecta Research Articles

Morphological and Molecular Characterization of Spirogyra Species from Water Bodies in Chiang Rai Province, Thailand: Insights into Bioactivity and Antioxidant Potentialin

This study aimed to identify Spirogyra species collected from lentic (sampling site code CR01) and lotic (sampling site code CR02) water areas in Chiang Rai Province, Thailand. The diagnosis was proceeded by studying the morphological characteristics combined with molecular techniques with the chloroplast rbcL gene (ribulose bisphosphate carboxylase). Additionally, the bioactive properties of Spirogyra extracts were evaluated through antimicrobial and antioxidant assays. The extraction was performed with water and ethanol extraction. The results indicated that the morphological characteristics of Spirogyra CR01 resembled Spirogyra neglecta, but the data of rbcL gene for this species were not available in the database. Therefore, the Spirogyra CR01 sequence was added to the GenBank database, representing the report of rbcL gene of Spirogyra neglecta sequencing data. Spirogyra CR02 was robustly identified as S. fluviatilisthrough molecular analysis. The extracts from both Spirogyra samples showed that the ethanolic extract has more activity than the water extract. The antimicrobial ability of the ethanolic extract from Spirogyra CR02 was observed to inhibit the growth of Bacillus cereus and Staphylococcus aureus, while the ethanolic extract from Spirogyra CR01 only inhibited B. cereus. Moreover, the ethanolic extract of Spirogyra CR01 had statistically significant (p<0.05) antioxidant activity, with the highest value recorded at 114.92±2.38 mg GAE/g extract. Overall, this study provides new sequencing information on the S. neglecta and their potential for use Spirogyra in functional food, functional ingredients and cosmeceutical products.

Exploring the Antimicrobial Potential of Spirogyra neglecta against MastitisInducing Pathogens

Exploring the Antimicrobial Potential of Spirogyra neglecta against MastitisInducing Pathogens

Phytochemical Compositions, Nutritional Contents, Cytotoxicity and Anti-Inflammatory Activity of Different Extracts from Spirogyra neglecta (Hassall) Kützing

Spirogyra neglecta (Hassall) Kützing is an edible freshwater macroalga. It is available and consumed as local food in Thailand, especially in the northern and northeastern parts. To ascertain its good benefit for health and safe for consumption, this study was, therefore carried out to determine the phytochemical compositions, nutritional contents, cytotoxicity, and anti-inflammatory activity of the different extracts from S. neglecta. The extracts were prepared by using different solvents, such as propylene glycol, methanol, and ethanol solutions. GC-MS analysis revealed the presence of 30, 39 and 36 phytochemical compounds in propylene glycol, methanol, and ethanol extracts, respectively. Phytol, which has been reported to have anti-inflammatory activity, was one of the predominant compositions in the extracts. The extracts contained high nutritional contents of protein, lipid, fiber, ash, moisture, and carbohydrate up to 21.68 ± 4.52, 3.53 ± 0.23, 14.77 ± 0.89, 10.73 ± 0.47, 9.79 ± 0.11 and 47.36 ± 3.89 %, respectively. The highest total protein was found in propylene glycol extract. The highest total lipid was in ethanol extract. Meanwhile, the highest fiber, ash and total carbohydrate were in methanol extract. In addition, all the extracts possess relatively low cytotoxicity, with IC50 values greater than 1,000 µg/mL. The extracts 1,000 µg/mL exhibited anti-inflammatory activity via inhibition Nitric oxide (NO) production by 29.87 ± 1.56 to 55.17 ± 1.91 %. The propylene glycol extracts from S. neglecta showed the highest inhibitory activity on NO production compared to others. The overall results indicating the propylene glycol is the solvent that produces the best extraction performance. The extracts from S. neglecta exhibit anti-inflammatory activity by inhibiting NO production. The phytochemical compositions are partly responsible for anti-inflammatory activity of the extracts. The high nutritional contents complement relatively low toxic. Thus, S. neglecta can be used as benefit natural sources for food products, supplements, and medicinal plants. HIGHLIGHTS Using GC-MS analysis, there are 30, 39 and 36 phytochemical compounds in propylene glycol, methanol and ethanol extracts from Spirogyra neglecta, respectively The extracts from neglecta possess high nutritional contents of protein, lipid, fiber, ash, moisture, and carbohydrate The extracts from neglecta show relatively low toxic to the RAW 246.7 cells with LC50 >1,000 µg/mL, by MTT assay The extracts from neglecta exhibit anti-inflammatory activity by inhibition of NO production. The propylene glycol extract displays the highest activity compared to others The anti-inflammatory activity of the extracts is partially from Phytol GRAPHICAL ABSTRACT

Spirogyra neglecta (Hassall) Kützing attenuates metastasis of castration-resistant human prostate cancer via the blockage of AKT signaling pathway

Spirogyra neglecta (Hassall) Kützing, a filamentous fresh water green alga, has clearly demonstrated its anti-inflammation properties; however, the anti-metastasis activity of this plant has not yet been elucidated. This study aimed to investigate the anti-metastasis effects of S. neglecta against castration-resistant prostate cancer cells. Transwell assays were used to determine the anti-metastasis properties of S. neglecta against PC3 cells. Furthermore, the metabolic profiling, 1H-NMR based metabolomics analysis, was conducted to identify the potential active compounds. The results revealed that S. neglecta ethanolic extract (SnEE) significantly inhibited PC3 cells invasion and migration. The metabolomics for the profiling-based screening of very well-known medicinal herbs in Asian countries (S. neglecta, S. platensis, T. erecta, C. siamea) have indicated a significant positive association between gallic acid, gentisic acid and the anti-metastasis properties of the SnEE. Thus, the solvent-partition technique was performed to concentrate the phenolic compounds in SnEE and then to establish the S. neglecta ethyl acetate fraction (SnEA). Mechanistically, SnEA inhibited PC3 cells metastasis through the inhibition of MMP-9 secretion, epithelial-mesenchymal transition, and the Akt signaling pathway (p<0.01). Our study, for the first time, showed that S. neglecta extract displayed remarkable anti-metastasis properties against castration-resistant prostate cancer by inhibiting the Akt signaling pathway. These findings appeared to support the use of S. neglecta extract as a natural supplement in the effective treatment of prostate cancer.

Spirogyra neglecta Aqueous Extract Attenuates LPS-Induced Renal Inflammation.

Spirogyra neglecta (SN), commonly named "Tao" in Thai, is a genus of filamentous green macroalgae. SN contains polyphenols such as isoquercetin, catechin, hydroquinone and kaempferol. These constituents exhibit beneficial effects including anti-oxidant, anti-gastric ulcer, anti-hyperglycaemia and anti-hyperlipidaemia in both in vitro and in vivo models. Whether SN extract (SNE) has an anti-inflammatory effect in vivo remains unclear. This study examined the effect of SNE on renal function and renal organic transport in lipopolysaccharide (LPS)-induced renal inflammation in rats. Rats were randomised and divided into normal saline (NS), NS supplemented with 1000 mg/kg body weight (BW) of SNE (NS + SNE), intraperitoneally injected with 12 mg/kg BW of LPS and LPS treated with 1000 mg/kg BW of SNE (LPS + SNE). Biochemical parameters in serum and urine, lipid peroxidation concentration, kidney function and renal organic anion and cation transports were determined. LPS-injected rats developed renal injury and inflammation by increasing urine microalbumin, total malondialdehyde (MDA) and inflammatory cytokines, tumor necrosis factor (TNF)-α and interleukin (IL)-1β protein expression, respectively. In addition, uptake of renal organic anion, [3H]-oestrone sulphate (ES), was reduced in LPS-injected rats together with increased expression of organic anion transporter 3 (Oat3). However, the renal injury and inflammation, as well as impaired Oat3 function and protein expression, were restored in LPS + SNE rats. Accordingly, SNE could be developed as nutraceutical product to prevent inflammation-induced nephrotoxicity.

Beneficial effects of Spirogyra Neglecta Extract on antioxidant and anti-inflammatory factors in streptozotocin-induced diabetic rats.

Objectives This study was conducted to evaluate the effects of oral supplementation of Spirogyra algae on oxidative damages and inflammatory responses in streptozotocin (STZ)-induced diabetic rats. Methods Diabetes was induced by administration of 55 mg/kg of streptozotocin. A total of sixty-four rats were divided into eight groups of eight rats each as follows:1) non-diabetic control; 2, 3, and 4) non-diabetic rats treated with 15, 30, and 45 mg of Spirogyra algae/kg/d; 5) control diabetic; and 6, 7, and 8) diabetic rats treated with 15, 30, and 45 mg of Spirogyra algae extract. At the end of the trial, the serum concentrations of glucose, interleukin-6 (IL-6), tumor necrosis factor-a (TNF-a), malondialdehyde (MDA), glutathione (GSH), total antioxidant status (TAS), C-reactive protein (CRP), insulin, triglycerides, and cholesterol were examined by specified procedures. Results Our findings indicated that the administration of STZ significantly increased the serum concentrations of glucose, triglycerides, cholesterol, CRP, IL-6, TNF-a, and MDA and decreased the serum levels of GSH and TAS (P<0.05) in diabetic rats. Oral administration of Spirogyra alleviated adverse effects of diabetes on oxidative stress and inflammatory factors in diabetic rats (P<0.05). Conclusion It can be stated that Spirogyra algae extract can be used for treatment of diabetes likely due to prevention of oxidative stress and alleviation of inflammation in the rat model.

Screening for Biological Activities of Spirogyra neglecta Water Extract

The freshwater green algae, S. neglecta, has been commonly used as a Northern Thai local food due to the fact that it is composed of several nutritional components. The aim of the present study was to investigate the phytochemical properties and biological activities of an S. neglecta water extract for application as a functional food or pharmaceutical ingredient. The phenolic and flavonoid contents of S. neglecta and its biological activities, including anti-oxidant, pancreatic cholesterol esterase, anti-inflammatory, cytotoxic, and antibacterial activities, were investigated in vitro. The results showed that the S. neglecta extract contained 157.92 mg GAE/g extract of phenolics and 10.10 mg CE/g extract of flavonoids. The radical scavenging activity of the S. neglecta extract exhibited an IC50 of 7.46±1.17 µg/mL from DPPH assay and 224.20±1.06 µg/mL from ABTS assay. Meanwhile, trolox exhibited an IC50 of 7.03±1.08 µg/mL from DPPH assay and 5.24±1.10 µg/mL from ATBS assay. Interestingly, the S. neglecta extract at 10 mg/mL inhibited pancreatic cholesterol esterase activity by 60 %. Moreover, the release of TNF-α from macrophages was strongly reduced by incubation with the S. neglecta extract in a dose-dependent manner, and all of the study concentrations were non-toxic to primary fibroblast cells. In addition, the S. neglecta extract inhibited some gram-positive and -negative bacteria. In summary, S. neglecta extract could possibly be used as a potential functional food or pharmaceutical ingredient, for which further studies are required.

Effect of Spirogyra neglecta on the early stages of 1, 2-dimethylhydrazine-induced colon carcinogenesis in rats.

This study focused on the chemopreventive effects of Spirogyra neglecta extract (SNE) and dried S. neglecta mixed diet on the early stages of 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis in rats. Male Wistar rats were injected with DMH to initiate aberrant crypt foci (ACF) formation. In the initiation stage, SNE significantly decreased the number of ACF in the colon of DMH-treated rats. Rats that received a low dose of SNE showed enhanced activity of several detoxifying and antioxidant enzymes. In the postinitiation stage, a low dose of SNE significantly decreased the number of ACF in the colon of DMH-treated rats. It significantly reduced the number of proliferating cell nuclear antigen-positive cells and increased the number of apoptotic cells in colonic crypts. S. neglecta thus inhibited the development of the early stages of DMH-induced colon carcinogenesis in rats by modulation of xenobiotic metabolizing enzymes and inhibition of cell proliferation as well as induction of apoptosis.

Spirogyra neglecta inhibits the absorption and synthesis of cholesterol in vitro

BackgroundSpirogyra neglecta (SN) has many nutritional benefits and it is commonly used to ameliorate different human conditions including inflammation, gastric ulcer, hyperglycemia, and hyperlipidemia. However, the mechanism of the hypocholesterolemic effect of SN still remains unclear. Therefore, the present study was aimed to evaluate the effect of SN extract particularly on cholesterol absorption and synthesis mechanisms. MethodsFor cholesterol absorption, the uptake of cholesterol was measured by using tritium radiolabeling of cholesterol in Caco-2 cells. Bile acid binding, micelles size, and cholesterol solubility were analyzed in in vitro assays, while cholesterol synthesis was evaluated by using a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase assay kit. ResultsSN extract was found to decrease cholesterol uptake in Caco-2 cells and decreased the solubility of cholesterol in micelles. The SN extract bound to taurocholate, taurodeoxycholate, and glycodeoxycholate bile acids, and increased micelles size. SN has also demonstrated an inhibitory effect on HMG-CoA reductase (HMGR) enzymatic activity. For further experimentation, the treatment combination of SN and ezetimibe (0.04mg/mL) showed a greater significant reduction in cholesterol uptake than the extract alone. ConclusionThese observations suggested that inhibitory cholesterol absorption effects of SN could be mediated through the modulation of size and solubility of cholesterol micelles, resulting in interference of cholesterol uptake. In addition, SN inhibited the rate limiting step of cholesterol synthesis. This study provides supporting evidence for the potential usage of SN as a cholesterol lowering agent.

Preventive Effects of Spirogyra neglecta and a Polysaccharide Extract against Dextran Sodium Sulfate Induced Colitis in Mice

Ulcerative colitis (UC) results from colonic epithelial barrier defects and impaired mucosal immune responses. In this study, we aimed to investigate the modifying effects of a Spirogyra neglecta extract (SNE), a polysaccharide extract (PE) and a chloroform fraction (CF) on dextran sodium sulfate (DSS)-induced colitis in mice and to determine the mechanisms. To induce colitis, ICR mice received 3% DSS in their drinking water for 7 days. Seven days preceding the DSS treatment, oral administration of SNE, PE and CF at doses of 50, 25 and 0.25 mg/kg body weight (low dose), 200, 100 and 1 mg/kg body weight (high dose) and vehicle was started and continued for 14 days. Histologic findings showed that DSS-induced damage of colonic epithelial structure and inflammation was attenuated in mice pre-treated with SNE, PE and CF. Furthermore, SNE and PE significantly protected colonic epithelial cells from DSS-induced cell cycle arrest, while SNE, PE and CF significantly diminished apoptosis. Proteome analysis demonstrated that SNE and PE might ameliorate DSS-induced colitis by inducing antioxidant enzymes, restoring impaired mitochondria function, and regulating inflammatory cytokines, proliferation and apoptosis. These results suggest that SNE and PE could prevent DSS-induced colitis in ICR mice by protection against and/or aiding recovery from damage to the colonic epithelium, reducing ROS and maintaining normal mitochondrial function and apoptosis.

Spirogyra neglecta, freshwater green alga, modulates the early stages of 1,2-dimethylhydrazine-induced colon carcinogenesis in rats

Spirogyra neglecta, freshwater green alga, modulates the early stages of 1,2-dimethylhydrazine-induced colon carcinogenesis in rats

Characterization and immunomodulatory activities of polysaccharides from Spirogyra neglecta (Hassall) Kützing.

Sulfated polysaccharides (SP) isolated from freshwater green algae, Spirogyra neglecta (Hassall) Kützing, and fractionated SPs were examined to investigate their molecular characteristics and immunomodulatory activity. The crude and fractionated SPs (F1, F2, and F3) consisted mostly of carbohydrates (68.5-85.3%), uronic acids (3.2-4.9%), and sulfates (2.2-12.2%) with various amounts of proteins (2.6-17.1%). D-galactose (23.5-27.3%), D-glucose (11.5-24.8%), L-fucose (19.0-26.7%), and L-rhamnose (16.4-18.3%) were the major monosaccharide units of these SPs with different levels of L-arabinose (3.0-9.4%), D-xylose (4.6-9.8%), and D-mannose (0.4-2.3%). The SPs contained two sub-fractions with molecular weights (Mw) ranging from 164 × 10(3) to 1460 × 10(3) g/mol. The crude and fractionated SPs strongly stimulated murine macrophages, producing considerable amounts of nitric oxide and various cytokines via up-regulation of their mRNA expression by activation of nuclear factor-kappa B and mitogen-activated protein kinases pathways. The main backbone of the most immunoenhancing SP was (1→3)-L-Fucopyranoside, (1→4,6)-D-Glucopyranoside, and (1→4)-D-Galactopyranoside.

Biogas production experimental research using algae.

The current study is on the the use of macro-algae as feedstock for biogas production. Three types of macro-algae, Cladophora glomerata (CG), Chara fragilis (CF), and Spirogyra neglecta (SN), were chosen for this research. The experimental studies on biogas production were carried out with these algae in a batch bioreactor. In the bioreactor was maintained 35 ± 1°C temperature. The results showed that the most appropriate macro-algae for biogas production are Spirogyra neglecta (SN) and Cladophora glomerata (CG). The average amount of biogas obtained from the processing of SN – 0.23 m3/m3d, CG – 0.20 m3/m3d, and CF – 0.12 m3/m3d. Considering the concentration of methane obtained during the processing of SN and CG, which after eight days and until the end of the experiment exceeded 60%, it can be claimed that biogas produced using these algae is valuable. When processing CF, the concentration of methane reached the level of 50% only by the final day of the experiment, which indicates that this alga is less suitable for biogas production.

Cancer Chemopreventive Effect of Spirogyra Neglecta (Hassall) Kützing on Diethylnitrosamine-Induced Hepatocarcinogenesis in Rats

Spirogyra neglecta, a freshwater green alga, is a local food in the northern and northeastern parts of Thailand. This investigation explored the anticarcinogenicity of S neglecta and its possible cancer chemopreventive mechanisms in rats divided into 14 groups. Groups 1 and 10 served as positive and negative control groups, respectively. Groups 1-9 were intraperitoneally injected with diethylnitrosamine (DEN) once a week for 3 weeks. Groups 10-14 received normal saline instead. One week after the last DEN injection, groups 2-5 were administered for 9 consecutive weeks various doses of S neglecta extract (SNE) and dried S neglecta (SND), mixed with basal diet. Groups 6-9 and 11-14 similarly were administered various doses of SNE and SND starting from the first week of the experiment. Administration of SNE and SND was not associated with formation of glutathione-S- transferase placental form (GST-P) positive foci in rat liver. SNE and SND during initiation phase significantly reduced the number of GST-P positive foci in rats injected with DEN. The number of GST-P also diminished in groups treated with SNE and SND after injection with DEN, except for the low dose extract group. SNE showed stronger anticarcinogenic potency than SND. Furthermore, SNE also decreased the number of Ki-67 positive cells. However, the numbers of TUNEL-positive cells in the liver of the SNE-treated groups were not statistically different from the controls. The GST activity in 50 mg/kg bw of SNE and 1% of SND groups was significantly increased as compared to the positive control. In conclusion, Spirogyra neglecta (Hassall) Kutzing showed cancer chemopreventive properties at the early stages of diethylnitrosamine-induced hepatocarcinogenesis in rats. Possible inhibitory mechanisms include enhancement of the activities of some detoxifying enzymes and/or suppression of precancerous cells.

The antimutagenic and antioxidant properties of Spirogyra neglecta (Hassall) Kützing

Spirogyra species is a freshwater filamentous green alga. Consumed as food in Northern Thailand, the algae have shown hypoglycemic ability in rats. The aims of this study were to investigate the chemical composition, antioxidant and antimutagenic activities in vitro of the aqueous extract of Spirogyra neglecta (Hassall) Kutzing. The antioxidant activity was evaluated by assessing the inhibition of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. The IC50 value of S. neglecta extract was 48.67±3.06 µg/ml in the DPPH scavenging assay. The mutagenicity and antimutagenicity were determined via the Ames test with and without metabolic activation. The extract did not enhance the numbers of revertant colonies ofSalmonella typhimurium strains TA98 and TA100 in the absence and presence of metabolic activation; this indicates non-mutagenicity. The extract was strongly effective in reducing the mutagenicity induced by 2-aminoanthracene (2-AA), 2-aminofluorene (2-AF), aflatoxin B1 (AFB1) and 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ) and weakly inhibited mutagenesis induced by 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP). The algae extract did not reduce the numbers of revertant colonies induced by a direct mutagen 2-(2-furyl)-3-(5-nitro-2-furyl)-acrylamide (AF-2) and NaN3. The water extract of S. neglectashowed antioxidant activity and protection from indirect mutagens in S. typhimurium. The possible antimutagenic mechanism of S. neglecta aqueous extract might be due to the inhibition of some metabolizing enzymes of mutagen metabolism Key words: Ames test, antimutagenicity, antioxidant, Spirogyra species.

Evaluation of hepatic antioxidant capacities of Spirogyra neglecta (Hassall) Kützing in rats.

Free radicals are one of the causes of chronic and degenerative diseases. Antioxidants can protect the progression of free radical mediated disorders. The aim of this study was to evaluate the antioxidant activity of Spirogyra neglecta (Hassall) Kützing in rats. The rats were divided into 5 groups. Group 1 served as control. Groups 2 and 3 were administered hot water extract of S. neglecta at 50 and 200 mg/kg bw, respectively, while groups 4 and 5 were fed 1% and 4% S. neglecta mixed diet, resp., for 13 weeks. Antioxidant enzymes were evaluated in livers of the rats. The activities of catalase and glutathione reductase were significantly increased in the group fed 50 mg/kg of the extract, compared with the control group. Glutathione peroxidase activity was also significantly higher in the group fed 50 and 200 mg/kg of the extract. The study suggests that S. neglecta may enhance antioxidant systems in the rat liver.

Antioxidant and renoprotective effects of Spirogyra neglecta (Hassall) Kützing extract in experimental type 2 diabetic rats.

Spirogyra neglecta extract (SNE) has shown antihyperglycemia and antihyperlipidemia in type 2 diabetic mellitus (T2DM) rats. This study investigated the antioxidant and renoprotective effects of SNE in T2DM rats induced by high-fat diet with low-single dose streptozotocin. T2DM rats were fed daily with SNE (0.25, 0.5, and 1 g/kg BW) for 12 weeks. Renal morphology, malondialdehyde levels, qPCR, and western blotting were analyzed. Renal cortical slices were used to determine renal transport of organic anions, which are estrone sulfate and para-aminohippurate, mediated through organic anion transporter 3-Oat3. Insulin and PKCζ were known to activate Oat3 function while it was inhibited by PKCα. Compared to T2DM, plasma glucose, triglyceride, insulin resistance, renal morphology, and malondialdehyde levels were significantly improved by SNE supplementation. Reduced glutathione peroxidase and nuclear factor κB expressions were related to antioxidant effect of SNE. Oat3 mRNA and protein were not different among groups, but insulin-stimulated rOat3 followed by anion uptakes was abolished in T2DM. This was restored in the slices from SNE treatment. The mechanism of SNE-improved Oat3 was associated with PKCα and PKCζ expressions and activities. These findings indicate that SNE has beneficial effects on renal transport through antioxidant enzymes and PKCs in T2DM rats.

Continuous metal removal from solution and industrial effluents using Spirogyra biomass-packed column reactor

The granules of Spirogyra neglecta biomass, diameter 0.2–0.5 mm, were successfully prepared by boiling it in urea–formaldehyde mixture. Metal sorption performance of the column packed with Spirogyra granules was assessed under variable operating conditions, such as, different influent metal concentrations, bed heights and flow rates. These conditions greatly influenced the breakthrough time and volume, saturation time and volume, and the ability of the column to attain saturation after reaching the breakthrough. The experimental breakthrough curves obtained under varying experimental conditions were modeled using Bohart–Adams, Wolborska, Thomas, Yoon–Nelson and modified dose–response models. The first two models were valid only in representing the initial part of the breakthrough curves; however, the other three models were good in representing the entire breakthrough curve. The granule-packed column could be successfully used up to 6 and 9 cycles of sorption and desorption for the removal of Cu(II) and Pb(II), respectively. The column could efficiently remove different metals from real industrial effluents, and hence the test biomass ( Spirogyra granules) is a good candidate for commercial application.

Characterization of the Adsorption of the Lead (II) by the Nonliving Biomass Spirogyra neglecta (Hasall) Kützing

Problem statement: Conventional techniques for removing dissolved heavy metals are only practical and cost-effective when applied to high strength wastes with heavy metal ion concentrations greater than 100 ppm. The possibility of using a nonliving algal biomass to solve this problem was carried in this study. Lead (II) was used in this study because it had been reported to cause several disorders in human. Approach: The nonliving algal biomass was obtained from a filamentous green alga Spirogyra neglecta. The effects of initial concentration and contact time, pH and temperature on the biosorption of lead (II) by the nonliving algal biomass were studied. The equilibrium isotherms and kinetics were obtained from batch adsorption experiments. The surface characteristics of the nonliving algal biomass were examined using scanning electron microscope and Fourier Transformed Infrared. The maximum adsorption capacity of the nonliving algal biomass was also determined. Results: Maximum adsorption capacity of lead (II) was affected by its initial concentration. Adsorption capacity of lead (II) increased with the pH and temperature of lead (II) solution. Langmuir isothermic model fitted the equilibrium data better than the Freundlich isothermic model. The adsorption kinetics followed the pseudo-second-order kinetic model. The nonliving algal biomass exhibited acaves-like, uneven surface texture along with lot of irregular surface. FTIR analysis of the alga biomass revealed the presence of carboyl, amine and carboxyl group which were responsible for adsorption of lead (II). The maximum adsorption capacity (qmax) of lead (II) by the nonliving biomass of Spirogyra neglecta was 132 mg g-1. Conclusion: The maximum adsorption capacity for lead (II) by the nonliving biomass of Spirogyra neglecta was higher than reported for other biosorbents. Therefore, it had a great potential for removing lead (II) from polluted water. Its use will also need to consider the various factors that affect biosorption process.

Copper(II) and lead(II) sorption from aqueous solution by non-living Spirogyra neglecta

Dried biomass of Spirogyra neglecta rapidly sorbed the test metals and the process became saturated in 10–20 min. Maximum sorption of Pb(II) [116.1 mg g −1] and Cu(II) [115.3 mg g −1] occurred at 0.1 g l −1 biomass and 100 mg l −1 metal concentration in the solution. Sorption of Cu(II) and Pb(II) occurred optimally at pH 4.5 and 5.0, respectively. Lead(II) and Cu(II) sorption were lesser from binary metal solution than from single metal solution. Lead(II) more severely inhibited Cu(II) sorption than vice versa thus reflecting greater affinity of Pb(II) for the biomass. NaOH pretreatment slightly enhanced the metal removal ability of the biomass. During repeated sorption/desorption cycles, Pb(II) and Cu(II) sorption decreased by 11% and 27%, respectively, at the end of the fifth cycle due inter alia to 10–15% loss of biomass. Nevertheless, Spirogyra appears to be a good sorbent for removing metals Cu(II) and Pb(II) from wastewaters.