Chlorococcum

About: Chlorococcum is a research topic. Over the lifetime, 268 publications have been published within this topic receiving 7317 citations.

Evaluation of antioxidant capacities of green microalgae

Abstract: Three strains of green microalgae, Chlorococcum sp.C53, Chlorella sp. E53, and Chlorella sp.ED53 were studied for their antioxidant activities. Crude extracts of these microalgae in hot water and in ethanol were examined for their total phenolic contents and for their antioxidant capacities. In order to determine their phenolic contents, the Folin–Ciocalteu method was used. As for the determination of their antioxidant capacities, four different assays were used: (1) total antioxidant capacity determination; (2) DPPH radical scavenging assay; (3) ferrous ion chelating ability assay; and (4) inhibition of lipid peroxidation (using thiobarbituric acid reactive substance). For all the strains we have studied, their ethanolic extract showed more antioxidant activities than their hot water extract. Categorically, the ethanolic extract of Chlorella sp.E53 exhibited both the highest total phenolic content of 35.5 ± 0.14 mg gallic acid equivalent (GAE) g−1 dry weight and the highest DPPH radical scavenging of 68.18 ± 0.38 % at 1.4 mg mL−1 (IC50 0.81 mg mL−1), whereas Chlorella sp.ED53 showed both the highest ferrous ion chelation activity of 42.78 ± 1.48 % at 1 mg mL−1 (IC50 1.23 mg mL−1) and the highest inhibition of lipid peroxidation of 87.96 ± 0.59 % at 4 mg mL−1. This high level of inhibition is comparable to 94.42 ± 1.39 % of butylated hydroxytoluene, a commercial synthetic antioxidant, at the same concentration.

Early stages of biofilm succession in a lentic freshwater environment

Abstract: Initial events of biofilms development and succession were studied in a freshwater environment at Kalpakkam, East Coast of India. Biofilms were developed by suspending Perspex (Plexiglass) panels for 15 days at bimonthly intervals from January 1996 to January 1997. Changes in biofilm thickness, biomass, algal density, chlorophyll a concentration and species composition were monitored. The biofilm thickness, biomass, algal density and chlorophyll a concentration increased with biofilms age and colonization was greater during summer (March, May and July) than other months. The initial colonization was mainly composed of Chlorella vulgaris, Chlorococcum humicolo (green algae), Achnanthes minutissima, Cocconeis scutellum, C. placentula (diatoms) and Chroococcus minutus (cyanobacteria) followed by colonial green algae such as Pediastrum tetras, P. boryanum and Coleochaete scutata, cyanobacteria (Gloeocapsa nigrescens), low profile diatoms (Amphora coffeaeformis, Nitzschia amphibia, and Gomphonema parvulum) and long stalked diatoms (Gomphoneis olivaceum and Gomphonema lanceolatum). After the 10th day, the community consisted of filamentous green algae (Klebshormidium subtile, Oedogonium sp., Stigeoclonium tenue and Ulothrix zonata) and cyanobacteria (Calothrix elenkinii, Oscillatoria tenuis and Phormidium tenue). Based on the percentage composition of different groups in the biofilm, three phases of succession could be identified: the first phase was dominated by green algae, the second by diatoms and the third phase by cyanobacteria. Seasonal variation in species composition was observed but the sequence of colonization was similar throughout the study period.

Effect of light and temperature on biomass, photosynthesis and capsular polysaccharides in cultured phototrophic biofilms

Abstract: Phototrophic biofilms seem to be suitable candidates for tertiary wastewater treatment due to their high uptake capacity for nutrients and other pollutants, also taking into account the time and cost savings derived from easy procedures for biomass harvesting. Biomass accrual, structure, and physiology of biofilms affect the efficiency of nutrient removal by its microbial community. Here, we construct a biofilm consisting of a cyanobacterium Synechocystis sp. and the green alga Chlorococcum sp. and determine the effect of combined variations of irradiance and temperature on the biofilm structure and function. The two species were isolated from phototrophic biofilms naturally developing in an Italian wastewater treatment plant and grown in a microcosm designed for biofilm investigations. Phototrophic biomass accumulation, percent species composition, photosynthetic response and the amount and composition of capsular polysaccharides (CPS), including anionic residues, are reported. The results showed that biofilm development required relatively moderate irradiances (60 μmol photons m−2 s−1) below which development was arrested. Both light and temperature had a strong effect on the composition of each species to the biofilm. The CPS compositions also changed with temperature, light and species composition. The CPS of the green-algal-dominated biofilm had the higher uronic acid content indicating a potential to exploit green algae in the treatment of waste contaminated with heavy metals. Given the knowledge of the response of certain species to light and temperature combinations, it may be possible to construct biofilms of known species and CPS composition to use them for specific applications.

Sorption of mercury, cadmium and lead by micro algae

Abstract: Forty-six strains of microalgae from BIOTECH Culture Collection (NSTDA), Microbiological Resources Center (TISTR) and Institute of Research and Food Development, 3 strains collected from Thai natural and industrial areas and 3 strains from the Gottingen University culture collection were tested for Mercury (Hg), Cadmium (Cd) and Lead (Pb) removal in aqueous solutions. In green algae, the highest Hg removal was by Scenedesmus sp., Chlorococcum sp., Chlorella vulgaris var. vulgaris and Fischerella sp., (97%, 96%, 94% and 92%, respectively). In blue green algae, highest Hg removal was by Lyngbya spiralis, Tolypothirx tenuis, Stigonema sp., Phormidium molle (96%, 94%, 94% and 93%, respectively). For Cd removal in green algae, the highest was by Chlorococcum sp., T5, Fischerella sp., Chlorella vulgaris var. vulgaris and Scenedesmus acutus (94%, 94%, 91%, 89% and 88%, respectively). In blue green algae, highest Cd removal was by Lyngbya heironymusii, Gloeocapsa sp., Phormidium molle, Oscillatoria jasorvensis and Nostoc sp. (97%, 96%, 95%, 94% and 94%, respectively). In green algae, highest Pb removal was by Scenedesmus acutus, Chlorella vulgaris var. vulgaris, Chlorella vulgaris, Scenedesmus vacuolatus and Chlorella vulgaris, (89%, 88%, 85%, 85% and 84%, respectively). In blue green algae, highest Pb removal was by Nostoc punciforme, Oscillatoria agardhii, Gloeocapsa sp., Nostoc piscinale, Nostoc commune and Nostoc paludosum (98%, 96%, 96%, 94%, 94% and 92%, respectively). Scenedesmus acutus had the highest concentration factor (CF) at 3,412, 4,591 and 4,078 for Hg, Cd and Pb, respectively. Tolypothrix tenuis had the highest maximum adsorption capacity of 27 mg Hg/g dry wt. at a minimum concentration of 1.04 mg/l, Scenedesmus acutus had the highest maximum adsorption capacity of 110 mg Cd/g dry wt. at a minimum concentration of 48 mg/l and Chlorella vulgaris had the highest maximum adsorption capacity of 127 mg Pb/g dry wt. at a minimum concentration of 130 mg/l.