Codium Tomentosum Research Articles

Domesticated Populations of Codium tomentosum Display Lipid Extracts with Lower Seasonal Shifts than Conspecifics from the Wild-Relevance for Biotechnological Applications of this Green Seaweed.

In the last decades, the use of algae in biotechnology and food industries has experienced an exponential growth. Codium tomentosum is a green macroalgae with high biotechnological potential, due to its rich lipidome, although few studies have addressed it. This study aimed to investigate the seasonal changes in lipid and pigment profiles of C. tomentosum, as well as to screen its antioxidant activity, in order to evaluate its natural plasticity. Samples of C. tomentosum were collected in two different seasons, early-autumn (September/October) and spring (May), in the Portuguese coast (wild samples), and in a land-based integrated multitrophic aquaculture (IMTA) system (IMTA samples). Total lipid extracts were analysed by LC–MS, GC–MS, and HPLC, and antioxidant activity was screened through free radical scavenging potential against DPPH and 2,20-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radicals. Wild samples showed a high seasonal variability, modifying their lipidome and pigment profiles according to environmental shifts, while IMTA samples showed a relatively stable composition due to early-stage culturing in controlled conditions. The lipids that contributed the most to seasonal discrimination were glycolipids (monogalactosyl diacylglycerol - MGDG and digalactosyl diacylglycerol - DGDG) and the lyso forms of phospholipids and glycolipids. Lipid extracts showed antioxidant activity ranging from 61 ± 2 to 115 ± 35 µmol Trolox g−1 of lipid extract in DPPH assay and from 532 ± 73 to 927 ± 92 µmol Trolox g−1 of lipid extract in ABTS assay, with a more intense antioxidant activity in wild spring samples. This study revealed that wild specimens of C. tomentosum presented a higher plasticity to cope with seasonal environmental changes, adjusting their lipid, pigment, and bioactivity profiles, while IMTA samples, cultured under controlled conditions, displayed more stable lipidome and pigment compositions.

Abundance of green algae in the intertidal zone of Karang Papak Coastal, West Java, Indonesia

Green alge (Chlorophyta) is the one of macroalgae who have much function such as ecologically and economically that living in the intertidal zone. Several genera of Chlorophyta have been used by local society around coastal area of Karang Papak Coastal, West Java as local product, but the research about abundance of Chlorophyta in Karang Papak coastal was not yet understood. This research aims to study of abundance of green algae in the intertidal zone, Karang Papak Coastal, West Java, Indonesia. This study was conducted on November 2018 and collecting data were collected using ransect method and held in every week (following moon phase). The website of algaebase.org and macroalgae identification books was used to green algae identification and then the results was verified by professional researchers from Lembaga Ilmu Pengetahuan Indonesia (LIPI). Data analysis was performed by calculating the total individual of each type green algae. The results showed that green algae were found consist of 15 species and 6 genus. The highest abundance of green alga species is Ulva lactuta and the lowest one is Codium tomentosum. Its can be caused by environmental factors such as nutrition, temperate, seasonal and tides of seawater. This data can be used for complete data about Indonesian macroalgae and as suggestion for management and monitoring of macroalgae by government and local people to maintain the sustainability of Chlorophyta.

The microbiome of Codium tomentosum: original state and in the presence of copper.

Codium tomentosum, as all organisms, hosts transiently and permanently numerous microorganisms. These holobionts can undergo environmental pressures influencing both partners creating modifications/imbalances within the associations, which may directly influence their physiological status by selecting tolerant bacteria. Furthermore, the capability of remediation of the associated bacterioflora, in particular of metallic trace elements, may provide the host with survival potential in polluted environments. In this context, we incubated C. tomentosum thalli in the presence of copper and studied its influence on the reference bacteriome. Whatever the concentration of copper, no shift was evidenced on the bacteriome at the phylum level. However, a high copper concentration enriched the bacteriome of C. tomentosum in both the genera Clostridium and Pseudolteromonas.

Seaweed Extracts Effectiveness against Selected Gram-negative Bacterial Isolates

Aqueous and six solvent extracts of four seaweeds Codium tomentosum (Chlorophyceae); Corallina mediterranea, Hypnea musciformis (Rhodophyceae), and Sargassum vulgare (Phaeophyceae) were screened for their antibacterial activity against 10 gram-negative bacterial isolates. Seaweeds crude extracts potent antibacterial activity have been evaluated based on zone of inhibition (ZI), minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values as reported in manyresearches. Overall, aqueous algal extracts were non active against all tested isolates regardless examined seaweed species. It was noticed that ZIs were in the following order: S. vulgare (17 mm) against Acinetobacter baumannii and C. mediteranea (17 mm) against Salmonella typhimurium > H. musciformis (13 mm) against Escherichia coli O:157 > C. tomentosum (11 mm) against S. typhimurium. Data revealed that the S. vulgare extracts showed the most inhibitory activity by showing the lowest MIC50 value of 0.08 mg/mL (methanolic extract against Shigella flexneri and hexane extract against E. coli O:157 isolate) and also the lowest MBC value of 1.00 mg/mL (methanolic extract against S. typhimurium, Serratia marcescens, E. coli O:157 and Brucella melitensis isolates; and also with ethanolic extract against S. marcescens and E. coli O:157 isolates). Future studies on the S. vulgare extracts are required due to their importance as a potent, promising and cheap source of bioactive compounds for antibacterial pretreatment.

Production of Antifouling Paints’ using Environmentally Safe Algal Extracts on Laboratory Scale

Fouling is a result of the accumulation of bacterial growth, algae and sessile invertebrates on both natural and manmade submerged surface. To combat fouling ships must constantly undergo cleaning up and maintenance processes. This work aimed to evaluate new biocide antifouling paints produced from marine algae, and study their suppressive effect on slime film forming bacteria. In addition, the effect of the leached components from these wood coated surfaces containing algae on the characteristics of the contact seawater medium was investigated compared with two commercial marine paints. To evaluate the suppressive effect of algae containing coatings, extraction of the new biocide antifouling paints were done by mixing different ingredients % of binder, pigment, filler, stabilizer and solvent. The obtained paints were durable, long lasting with no cracking formed before their incorporation with algae. The paint formulations were applied to wood panels and immersed in sterile glass beakers filled with seawater medium collected from the Eastern Harbour, Alexandria, Egypt. The physicochemical parameters (temperature, salinity, pH, dissolved oxygen and nutrient salts) of seawater samples around the tested panels’ were measured after four weeks of immersion and the microbiological examination for the panels were measured after two and four weeks of immersion.Using of algae in the dry paint film leads to highest suppressive effect (%). The tested Ulva fasciata, Corallina mediterraneaand Codium Tomentosum were having the highest suppressive effect 100, 99.6 and 99.5%, respectively. These results matched with the characterization by gas chromatography-mass spectrophotometer (GC-MS) and Fourier transform infrared spectroscopy (FTIR).

Effect of three diets on the gametogenic development and fatty acid profile of Paracentrotus lividus (Lamarck, 1816) gonads

In this study, the effects of three diets were investigated to enhance Paracentrotus lividus production for commercial purposes. P. lividus were fed ad libitum for 80 days with: diet A—fresh Codium tomentosum Stackhouse, 1797; diet B—formulated using a jellified mix of macroalgae and vegetables, including C. tomentosum (20%), Coralina sp. Linnaeus, 1758 (17%), cabbage Brassica oleracea var. capitata Linnaeus, 1753 (30%), carrot Daucus carota Linnaeus, 1753 (30%) and agar (3%) as a gelling agent. Diet C consisted of maize Zea mays Linnaeus, 1753 (56%) and New Zealand spinach Tetragonia tetragonoides (Pallas, 1781) Kuntze, 1891 (44%). Their effects on the gonadal and somatic growths, gonadosomatic index (GI) and gametogenesis were evaluated, as well as on the total lipid content and fatty acid composition of sea urchin's gonads. Diet A provided high values of eicosapentaenoic acid (EPA). Gonads of sea urchins fed with diet A were found mostly in growth and maturation stages of gametogenesis and showed the lowest lipid content. Sea urchins fed with diet B presented their gonads in the reabsorption stage and had the highest values of omega-3 polyunsaturated fatty acids (PUFAs). Sea urchins fed with diet C were in the early stages of gametogenesis and had the highest values of lipid content, plus omega-6 PUFAs. Once as an ingredient in a balanced mix with vegetables, C. tomentosum can be a key factor to the development of new promising high-quality and low-cost feed for P. lividus roe enhancement.

Are seaweeds the food of the future? Challenges for its conservation and introduction in the Portuguese diet

Introduction: Seaweeds are well known for their nutritional value [1]. The ALGA4FOOD project [https://alga4food.wixsite.com/pt-pt] [2] aims: i) researching new seaweed conservation processes (e.g. lyophilization, pascalization, MAP, etc.) which optimize functional and organoleptic characteristics; ii) develop strategies for its introduction in the Portuguese diet. Materials and methods 1 : Raw Materials: Seven seweed species (Ulva rigida, Codium tomentosum, Undaria pinnatifida, Saccorhiza polyschides, Gracilaria gracilis, Osmundea pinnatifida, Chondracanthus teedei var. Lusitanicus) were collected in north and central Portugal. Porphyra sp. and Ulva rigida for sensorial analysis were cultivated in an IMTA system. Instrumental Analysis: Each seaweed was frozen with liquid nitrogen and ground. Samples were maintained at −20 °C until microextraction by HS-SPME, using 30 g of fresh seaweed and 104 g of milli-Q water with 30% NaCl (PA). Ulva rigida was also dried and 6.75 g of the dried seaweed and 117 g of the saline solution were used. Compounds extracted were analyzed and identified by GC-MS. Product Development and Sensory Analysis: Dried pastas enriched with U. rigida and Porphyra sp. were developed and affective acceptance tests, using as control a 100% semolina (Triticum durum) pasta, were performed. The panel was composed by 60 untrained testers, and a structured hedonic scale of 1 to 9 points was used for the evaluation of appearance, color, aroma, texture, flavour, overall impression and food suitability. Data was submitted to analysis of variance (ANOVA), and Tukey’s multiple comparison tests. Results: Instrumental analysis: GC-MS identified 57 different organic compounds (167 in total): 28 aldehydes, 4 alcohols; 10 hydrocarbons; 3 ethers; 8 ketones; 4 other functional groups (1 containing sulphur, 2 iodine and 1 bromine). For U. rigida, results showed that the main compounds contributing for its fresh flavour profile (β-ionone and 2,4-decadienal) were different from those for the dried seaweed, meaning that fresh U. rigida has a higher aromatic richness than the dried one. Sensory analysis: The results showed no significant differences between the average values for texture, flavour, overall impression and food suitability. However, the appearance, colour and aroma attributes were significantly different particularly for the control and Porphyra sp. formulations [3]. Discussion and conclusions: The exploratory process showed that both instrumental and sensorial analysis, as well as the concepts underlying cooking creativity [3], are of great value for the development of new seaweed food products. GC-MS technique, together with sensory analysis, showed similarities between Undaria pinnatifida and collard greens (Brassica oleracea var. Acephala). Based on this, the seaweed was introduced in the traditional soup “caldoverde”, and preliminary tests showed good acceptance. Sensory analysis of pasta showed that green seaweed, due to their subtle maritime flavour, have a greater potential for cooking applications than the red seaweed [2,3].

The use of green macroalgae (Ulva lactuca and Codium tomentosum) that have a high methane potential, as a source of biogas in Senegal

Anaerobic digestion is a biochemical process that occurs naturally in the absence of oxygen. It is used commonly in developing countries to produce both energy and biofertilizers.Objective: The purpose of this work was to study the anaerobic digestion of green macroalgae (Ulva lactuca and Codium tomentosum), which cause severe environmental problems in Dakar-Senegal, and elsewherealong Africa's Atlantic coast.Methodology and Results: These green macroalgae were characterized in terms of physicochemical properties and biochemical methane potential (BMP). Their characteristics were compared to those of other locally available feedstock, such as cow manure and Jatropha curcas cake. The results showed that volatile solids of macroalgae were about 500 g VS/kg and twice that of cow manure. Furthermore, the methane potential ofmacroalgae was twice (216.4 L CH4/kg VS) that of cow manure (100.3 L CH4/kg VS). The green macroalgae achieved a heating value potential of 2151 kWh/t VS. The methane potential of Jatropha cake as a substrate foranaerobic digestion was intermediate (133.6 L CH4/kg VS) but contained a large quantity of lignin (34%), a slowly biodegradable organic substance.Conclusions and application of findings: This study results showed that green macroalgae could be used as a substrate for the production of renewable energy the biogas in Senegal.Keywords: Biogas, renewable energy, biochemical methane potential, macroalgae, Jatropha curcas.

Lipidomics of solar-power animals: a tool to unravel the process of kleptoplasty

Lipidomics of solar-power animals: a tool to unravel the process of kleptoplasty

Investigation of common chemical components and inhibitory effect on GES-type β-lactamase (GES22) in methanolic extracts of Algerian seaweeds

This study aimed to investigate the total phenolic content (TPC), the identification of the common compounds by HPLC-ESI-MS and HPLC-ESI-MS-TOF and the inhibitory effects against class A-type β-lactamase (GES-22 variant, produced recombinantly) in methanolic extracts (MEs) of four Algerian seaweeds [Ulva intestinalis, Codium tomentosum, Dictyota dichotoma and Halopteris scoparia]. The TPC varied among the four species, ranging between 0.93 ± 0.65 and 2.66 ± 1.33 mg GAEs/g DW. C.tomentosum had higher total phenol content than other seaweeds while, all of them inhibited uncompetitively GES-22 activity in a dose-dependent manner. Nitrocefin was used as chromogenic substrate to evaluate the inhibitory effect on GES-22. The methanolic extract of D.dichotoma exhibited significant inhibitory effect on GES-22 (IC50 = 13.01 ± 0.046 μg/mL) more than clavulanate, sulbactam and tazobactam (classical β-lactam inhibitors) (IC50 = 68.38 ± 0.17 μg/mL, 52.68 ± 0.64 μg/mL, and 29.94 ± 0.01 μg/mL, respectively). IC50 of the other ME of U.intestinalis, C.tomentosum, and H.scoparia were 16.87 ± 0.10 μg/mL, 16.54 ± 0.048 μg/mL, and 25.72 ± 0.15 μg/mL, respectively. Except H. scoparia, other three seaweed extracts showed almost two times or more inhibition on GES-22. Furthermore, four common compounds in these MEs were identified, α-linolenic acid (C18:3ω3), linoleic acid (C18:2ω6), oleic acid (C18:1ω9), the eicosanoid precursors ‘‘arachidonic acid’’ (C20:4ω6). Baicalein (C15H10O5) was identified in U.intestinalis and D.dichotoma seaweeds. The fact that all seaweed extracts inhibited the GES-22 better than commercial samples makes these seaweeds candidate for discovering new inhibitors against β-lactamases. Besides that, they contain important components with potential health benefits.

INFLUENCE OF DIFFERENT HABITATS ON THE CHEMICAL CONSITUENTS OF CODIUM TOMENTOSUM

THE CURRENT study was conducted to assess the influence of different harvesting site (habitat) on the chemical constituents of Codium tomentosum Stack collected from two different sites on the coast of Egypt (Mediterranean [M] and Red [R] Seas). The current results showed that, salinity and temperature of the Red Sea is relatively higher than those of the Mediterranean one. Additionally, results indicated significant differences in the biochemical profiles of Codium between the two sampling sites. The total carbohydrate, proline, glycerol content together with total antioxidant capacity, reducing power as well as mineral content (Na+, K+ and Ca++) and the activities of antioxidant enzymes (PPO, POX, ASO, APX and CAT) of Codium collected from site R were significantly higher than of those collected from site M. In contrast, total protein, total amino acids, flavonoids contents were predominated in Codium harvested from the Mediterranean Sea. No significant differences in ascorbic acid, glutathione, chlorophyll a content and total phenols collected from the two sites. The electrophoretic analysis of protein pattern revealed the appearance of of 7 and 8 polypeptide bands in Codium from the two sites (M and R, respectively). However polypeptides with molecular weights 93, 72 and 42kDa were recorded only for Codium of site (M), while that of 17 kDa was specific for Codium of site (R). In conclusion, this study shows that the different sampling sites influences on biochemical profiles of Codium. However, Codium in response to extreme temperatures and salinity, may alter its metabolism, building a strong protection system and producing compatible solutes in various ways to overcome these stress. This result is a step towards to study the algal diverse biochemical integrations involved in cellular adaptation of algae to different environmental factors and habitats.

The ability to incorporate functional plastids by the sea slug Elysia viridis is governed by its food source

Functional kleptoplasty in sacoglossan sea slugs is among the most curious photosynthetic associations known. One member of these marine molluscs, Elysia viridis, is known to incorporate plastids from a variety of different algae food sources, but with apparently different outcomes and differences in the time span of the retention of functional kleptoplasts. While it was previously shown that kleptoplasts that stem from Codium tomentosum are kept functional for several weeks (long-term retention, LtR), those that stem from Bryopsis hypnoides or Cladophora rupestris are thought to be of limited use regarding photosynthetic capacity (short-term retention, StR). This is important, because it touches upon the popular yet controversial question of how important photosynthesis is for the thriving of these slugs. The aim of the present study was to determine to what degree the plastid source determines retention time. We, therefore, compared E. viridis feeding on either Cladophora sp. or B. hypnoides. We show that kleptoplasts of B. hypnoides incorporate 14CO2, but with rapidly declining efficiency throughout the first week of starvation, while the plastids of Cladophora sp. are, surprisingly, not incorporated to begin with. The radulae of the different samples showed adjustment to the food source, and when feeding on Cladophora sp., E. viridis survived under laboratory conditions under both starvation and non-starvation conditions. Our results demonstrate that (i) the ability to incorporate plastids by E. viridis differs between the food sources B. hypnoides and Cladophora sp., and (ii) photosynthetic active kleptoplasts are not an inevitable requirement for survival.

Influence of Codium tomentosum Extract in the Properties of Alginate and Chitosan Edible Films.

The growing search for natural alternatives to synthetic food packaging materials and additives has increased, and seaweed extracts’ bioactivity has made them suitable candidates for incorporation in novel edible films. This study aims to investigate the effect of Codium tomentosum seaweed extract (SE) incorporation in alginate and chitosan edible films. Alginate- and chitosan-based films with and without the incorporation of 0.5% SE were characterized according to their physical, optical, mechanical, and thermal properties. Seaweed extract incorporation in chitosan films resulted in an increase of film solubility (50%), elasticity (18%), and decrease of puncture strength (27%) and energy at break (39%). In alginate films, the extract incorporation significantly decreased film solubility (6%), water vapour permeability (46%), and elasticity (24%), and had no effect on thermal properties. Depending on the type of application, the addition of SE in edible films can bring advantages for food conservation.

Anticancer and Antioxidant Activities of Some Algae from Western Libyan Coast

Seaweeds are considered as one of the largest biomass producers in marine environment that is rich in bioactive metabolites and a source of natural ingredients for functional foods. The potential antioxidant activity and the potential inhibition of Caco2 cell proliferation, of crude extracts of: Chlorophyta (Ulva lactuca, and Codium tomentosum), Phaeophyta (Cystoseira crinita, Cystoseira stricta, and Sargassum vulgare), and Rhodophyta (Gelidium latifolium, Hypnea musciformis, and Jania rubens) were collected from western Libyan coast and evaluated in vitro. The antioxidant activity was determined by reducing power and DPPH assays while cell proliferation, morphological changes and the cell cycle arrest were assessed by MTT, inverted light microscope and flow cytometry methods respectively. The polyphenols and flavonoids rich extracts showed remarkable reducing power and antiradical properties. After exposure of Caco2 cells to various concentrations of extracts (50, 100, 150 and 200 μg/mL) especially from brown algae for 72 h, cell proliferation was reduced significantly. The antiproliferative effect of algae extracts was correlated with their polyphenol and flavonoid contents. Cell cycle analysis further showed that cells were arrested in G phases along with an increment in sub-diploidal cell population (sub-G) after extract application. These results imply that seaweeds which are rich in bioactive compounds may be used in anticancer drug research programs. However, further investigations are essential to reveal the molecular mechanisms of the anticancer activities of these algae.

Optical properties of Codium tomentosum seaweed like Bi2O3 nanostructure and its gas-sensing activity

Codium tomentosum seaweed structured Bi2O3 was prepared by anodization technique using thermally evaporated bismuth films. The present study concerns the development of an efficient CO2 sensor at room temperature by controlling the crystallinity, morphology, carrier concentration, and bang gap. Crystal structure variation was achieved by sequential annealing from 200 to 600 °C. During anodization, truncated polyhedral aggregates of bismuth particles get reformed into Codium tomentosum seaweed like nanostructures of Bi2O3. The nature of Bi2O3 semiconductor with carrier concentration has been identified from the Mott–Schottky plot. Lattice defects such as oxygen vacancies, Bi interstitials, recombination effect, and band gap values were analyzed through optical studies. The sensor study was performed at room temperature for the detection of CO2 gas in the concentration 10–100 ppm. Bi2O3 nanostructure annealed at 400 °C having amorphous nature offered the maximum response magnitude. The underlying, sensing mechanism was correlated with the experimental findings on the basis of optical properties and surface morphology.

Influence of annealing on phase transformation and specific capacitance enhancement in Bi2O3

Electrodes with nanostructures offer a better avenue to accomplish high performance supercapacitors. In view of this, seaweed like nanostructures of Bi2O3 was synthesized by electrochemical anodization of bismuth film in oxalic acid electrolyte. Even though, as-anodized films were amorphous, annealing promoted the crystallinity and promoted a phase transformation from β to γ-Bi2O3 on sequential annealing. Raman spectroscopy supported the XRD results of diminishing beta-phase Bi2O3 on sequential annealing, structural distortion and phase transformation. HRSEM images displayed the Codium tomentosum seaweed like nanostructure embedded with multiple nanofibers and nanoparticles. Cyclic voltammetry exhibited a maximum specific capacitance of 331Fg−1 for β-Bi2O3 electrode. The performance of Bi2O3 electrode pseudocapacitor depends on its phase crystallinity, morphology and charge carrier density. Impedance spectral analysis revealed that the increase in the specific capacitance was mainly owing to the decrease of charge transfer resistance and the fast ion diffusion in the electrode.

Kleptoplasty does not promote major shifts in the lipidome of macroalgal chloroplasts sequestered by the sacoglossan sea slug Elysia viridis

Sacoglossan sea slugs, also known as crawling leaves due to their photosynthetic activity, are highly selective feeders that incorporate chloroplasts from specific macroalgae. These “stolen” plastids - kleptoplasts - are kept functional inside animal cells and likely provide an alternative source of energy to their host. The mechanisms supporting the retention and functionality of kleptoplasts remain unknown. A lipidomic mass spectrometry-based analysis was performed to study kleptoplasty of the sacoglossan sea slug Elysia viridis fed with Codium tomentosum. Total lipid extract of both organisms was fractionated. The fraction rich in glycolipids, exclusive lipids from chloroplasts, and the fraction rich in betaine lipids, characteristic of algae, were analysed using hydrophilic interaction liquid chromatography-mass spectrometry (HILIC-LC-MS). This approach allowed the identification of 81 molecular species, namely galactolipids (8 in both organisms), sulfolipids (17 in C. tomentosum and 13 in E. viridis) and betaine lipids (51 in C. tomentosum and 41 in E. viridis). These lipid classes presented similar lipidomic profiles in C. tomentosum and E. viridis, indicating that the necessary mechanisms to perform photosynthesis are preserved during the process of endosymbiosis. The present study shows that there are no major shifts in the lipidome of C. tomentosum chloroplasts sequestered by E. viridis.

Algal biomass: A sustainable, economical and renewable approach for microbial production of pectinolytic enzymes using submerged and solid state fermentation techniques

In the past decade, algal waste has been used as useful natural resource for production of enormous range of products that have wide economical and commercial importance. Pectinases are group of enzymes that have wide commercial applications. Hence, current study was designed to utilize algal biomass for the production of pectinases using submerged (SmF) and solid state fermentation (SSF) techniques. Different algal sources including brown (Dictyopteris polypodioides, Sargassum wightii and Dictyopteris divaricata) and green algae (Ulva lactuca and Codium tomentosum) were used and U. lactuca was found to be the most suitable substrate. Several bacterial and fungal strains were screened and among them Bacillus licheniformis KIBGE-IB4 was selected based on maximum pectinase production. SmF and SSF were studied utilizing U. lactuca as a substrate and results revealed that enzyme production was favoured by SmF (2457 ± 3.31 U mg−1) as compared to SSF (1432 ± 1.46 U mg−1). Parametric optimization of pectinase production indicated that B. licheniformis KIBGE-IB4 requires 10.0 g L–1 U. lactuca as a biomass in the medium with a pH 7.0 when incubated at 37 °C for 24 hours. Likewise, production of pectinase using algal resource was also compared with that of the conventional agricultural biomass and it was observed that when U. lactuca was used, the selected bacterial isolate produced a higher yield of enzyme than sugarcane bagasse and rice husk. Hence, it is anticipated that algal biomass can be efficiently utilized as an environmental friendly bioresource for the production of industrially important hydrolytic enzymes.

Kleptoplast photosynthesis is nutritionally relevant in the sea slug Elysia viridis

Several sacoglossan sea slug species feed on macroalgae and incorporate chloroplasts into tubular cells of their digestive diverticula. We investigated the role of the “stolen” chloroplasts (kleptoplasts) in the nutrition of the sea slug Elysia viridis and assessed how their abundance, distribution and photosynthetic activity were affected by light and starvation. Elysia viridis individuals feeding on the macroalga Codium tomentosum were compared with starved specimens kept in dark and low light conditions. A combination of variable Chl a fluorescence and hyperspectral imaging, and HPLC pigment analysis was used to evaluate the spatial and temporal variability of photopigments and of the photosynthetic capacity of kleptoplasts. We show increased loss of weight and body length in dark-starved E. viridis as compared to low light-starved sea slugs. A more pronounced decrease in kleptoplast abundance and lower photosynthetic electron transport rates were observed in dark-starved sea slugs than in low light-starved animals. This study presents strong evidence of the importance of kleptoplast photosynthesis for the nutrition of E. viridis in periods of food scarcity. Deprived of photosynthates, E. viridis could accelerate the breakdown of kleptoplasts in the dark to satisfy its’ energy requirements.

Chromium(VI) adsorption by Codium tomentosum: evidence for adsorption by porous media from sigmoidal dose–response curve

Adsorption of Cr(VI) using native and chemically modified marine green macroalgae Codium tomentosum biomass and its adsorption kinetics were studied under specific conditions. Maximum Cr(VI) removal occurred at pH 2 for both untreated and acid-treated biomass. However, base-treated biomass exhibited maximum adsorption at pH 6 due to the hydrolysis of methyl esters present in the cellulose, hemicellulose and lignin molecules resulting in carboxyl groups (COO−) on the surface. The effect of adsorbent dose revealed that untreated and acid-treated biomass follows Henry’s linear isotherm, while base-treated biomass exhibited sigmoidal curve indicating energetic heterogeneity on the adsorbing surface. The monolayer adsorption capacity of untreated, acid-treated and base-treated biomasses was 5.032 ± 0.644, 5.445 ± 0.947, 3.814 ± 0.559 mg g−1, respectively. Adsorption was found to follow Ho and McKay’s pseudo-second-order kinetic model with decreasing pseudo-second-order rate constant (K 2, g mg−1 min−1) of 0.088 ± 0.037 (acid-treated), 0.019 ± 0.003 (untreated) and 0.012 ± 0.003 (base-treated).