Somatic organic content of the ctenophores <Emphasis Type="Italic">Mnemiopsis leidyi</Emphasis> (Ctenophora: Lobata) and <Emphasis Type="Italic">Beroe ovata</Emphasis> (Ctenophora: Beroida) in early ontogenetic stages

The organic matter content in the eggs and early larvae of the ctenophores Mnemiopsis leidyi and Beroe ovata from the Black Sea was determined using the adapted microtechnique of dichromate oxidation. The content of organic matter in the eggs of M. leidyi (0.25 μg/indiv.) was 5 times less than in B. ovata (1.28 ± 0.29 μg/indiv.). The somatic content of organic matter was 0.25 ± 0.09 μg/indiv. (25.1 ± 8.3 μg/mg, wet wt) for 2-day-old larvae of M. leidyi (0.2–0.3 mm in body length) and 1.37 ± 0.19 μg/indiv. (67.1 ± 5.7 μg/mg wet wt) for larvae of B. ovata (0.4 mm in body length). The specific organic content of larvae of both species steadily decreased with an increase in ctenophore body size and weight, approaching 3–4 μg/mg of wet weight for 2 mm specimens of M. leidyi and 3–5 μg/mg of wet weight for 6 mm B. ovata. The specific organic content of early larvae was 20–30 times higher than that of adult ctenophores. The results of this investigation could be useful in the evaluation of the energy budget for somatic growth and generative production in these species. Calculations indicate that with specific wet weight growth rates of 0.43/day for M. leidyi larvae and 0.29/day for B. ovata larvae, their true organic increases are respectively 30 and 38% less, i.e., no more than 0.31/day for the former and 0.18/day for the latter species.     

The biochemical and energetic composition of somatic body components of echinoderms from the northern Gulf of Mexico

• 1.1. The biochemical and energetic compositions of the somatic body components of seven species of asteroids, one ophiuroid, and four echinoids from the northern Gulf of Mexico (30–95 m depth) were ascertained.
• 2.2. Levels of ash were high (68.5–90.8% dry wt) in all body-wall tissues, with the exception of the asteroid Echinaster modestus (51.6% dry wt). Levels of ash were low in the pyloric cecae (nutrient storage organ) of asteroids (4.6–30.8% dry wt).
• 3.3. Levels of lipid (8.1–34.5% dry wt), soluble protein (15.9–28.7% dry wt), and insoluble protein (18.1–48.6%, dry wt) were high in the pyloric cecae of all asteroids, but generally low in ophiuroid and echinoid body-wall tissues. High protein levels (28.5–44.5% dry wt) in the body-wall of the asteroids Echinaster modestus and Anthenoides pierceisuggest it may play a role in nutrient storage.
• 4.4. All somatic tissues contained low levels of carbohydrate (0.2–1.4% dry wt).
• 5.5. Levels of energy in pyloric cecal tissues (12.99–26.05 kJ/g dry wt) were 4–8 times higher than in echinoderm body-wall tissues (2.92–11.91 kJ/g dry wt).
• 6.6. The biochemical and energetic compositions of echinoderms from the northern Gulf of Mexico are similar to those of species from other latitudes and depths.

     

Changes in chemical composition of hydrophyte leaves during adaptation to aquatic environment

Leaf chemical composition of 19 hydrophytes was studied. The content of carbon, nitrogen, nonstructural carbohydrates, organic acids, minerals, and water was determined. Hydrophytes were shown to contain less carbon (below 410 mg/g dry wt in 60% species) than terrestrial plants. Hydrophytes and terrestrial plants did not differ in the nitrogen concentration in the leaves (33 and 29 mg/g dry wt, respectively). Hydrophytes were characterized by a low content of organic acids (40–90 mg/g dry wt in 60% species) and high content of mineral compounds (90–170 mg/g dry wt in 50% species). Total amount of nonstructural carbohydrates was similar in the leaves of hydrophytes and terrestrial plants (from 120 to 190 mg/g dry wt), but the proportions of various carbohydrate fractions differed substantially. In the hydrophyte leaves, the content of soluble carbohydrates was 2.4-fold lower, whereas the content of nonstructural polysaccharides 1.2-fold higher than in terrestrial plant leaves. Two groups of correlations between parameters of leaf chemical composition were distinguished: the contents of carbon, nitrogen, and soluble sugars were positively correlated, and the negative correlation was observed between these parameters and the amounts of mineral compounds, organic acids, water, and nonstructural polysaccharides. We concluded that hydrophyte leaf chemical composition reflects a specificity of plant adaptation to aquatic environment.     

Exploring the potential of small RNA subunit and ITS sequences for resolving phylogenetic relationships within the phylum Ctenophora

Ctenophores are a phylum of non-bilaterian marine (mostly planktonic) animals, characterised by several unique synapomorphies (e.g., comb rows, apical organ). Relationships between and within the nine recognised ctenophore orders are far from understood, notably due to a paucity of phylogenetically informative anatomical characters. Previous attempts to address ctenophore phylogeny using molecular data (18S rRNA) led to poorly resolved trees but demonstrated the paraphyly of the order Cydippida. Here we compiled an updated 18S rRNA data set, notably including a few newly sequenced species representing previously unsampled families (Lampeidae, Euryhamphaeidae), and we constructed an additional more rapidly evolving ITS1 + 5.8S rRNA + ITS2 alignment. These data sets were analysed separately and in combination under a probabilistic framework, using different methods (maximum likelihood, Bayesian inference) and models (e.g., doublet model to accommodate secondary structure; data partitioning). An important lesson from our exploration of these datasets is that the fast-evolving internal transcribed spacer (ITS) regions are useful markers for reconstructing high-level relationships within ctenophores. Our results confirm the paraphyly of the order Cydippida (and thus a “cydippid-like” ctenophore common ancestor) and suggest that the family Mertensiidae could be the sister group of all other ctenophores. The family Lampeidae (also part of the former “Cydippida”) is probably the sister group of the order Platyctenida (benthic ctenophores). The order Beroida might not be monophyletic, due to the position of Beroe abyssicola outside of a clade grouping the other Beroe species and members of the “Cydippida” family Haeckeliidae. Many relationships (e.g. between Pleurobrachiidae, Beroida, Cestida, Lobata, Thalassocalycida) remain unresolved. Future progress in understanding ctenophore phylogeny will come from the use of additional rapidly evolving markers and improvement of taxonomic sampling.     

Polarization sensitivity in crayfish lamina monopolar neurons

1. Polarization sensitivity (PS) was examined in photoreceptors and lamina monopolar cells (LMCs) in two species of crayfish, Procambarus clarkii and Pacifasticus leniusculus. The measurements were made with intracellular recordings and broad field illumination.
2. PS is about 40% greater in Pacifasticus than in Procambarus (Table 1). In both species the LMC stationary PS profiles (estimated with flashes) are similar to those of receptors (Figs. 1 and 2). Both receptor and LMC sensitivity profiles are well described by cos² θ functions (Fig. 3). PS was observed in all receptors and 78% of LMCs.
3. When stimulated with a rotating polarizer, receptors and LMCs exhibit membrane potential modulation with phase predicted by the stationary PS profile (Fig. 5). In photoreceptors, the polarization-elicited percent modulation falls off steeply as intensity increases. The LMC modulation is stronger than that in receptors and relatively insensitive to the mean intensity (Figs. 6 to 8). For low intensities the LMC modulation is 100%. The LMC dynamic behavior is consistent with either an opponency mechanism or strong but polarization-insensitive lateral inhibition.
4. Receptors and LMCs exhibit steady-state differential sensitivity to stationary e-vector orientation (Fig. 9).
5. About 10% of the LMC neurons exhibit PS maxima separated by 90°. These results imply a nonlinear summation of signals from orthogonal receptor channels (Fig. 10).

     

Absorption efficiencies of Lytechinus variegatus (Lamarck) (Echinodermata: Echinoidea) for selected marine plants

The absorption efficiencies of the sea urchin Lytechinus variegatus (Lamarck) were calculated by an indicator method. Absorption efficiencies for total organic material, protein, lipid, and carbohydrate were highest with Halimeda incrassata Ellis as food (43 %, 65 %, 71 % and 35 %, respectively), and lowest with Eucheuma isiforme C. Agardh as food (?35%, ?42%, ?56%and ?34%, respectively). Moderately positive absorption efficiencies for total organic material were found with Thalassia testudinum König & Sims and Ulva lactuca L. as food, and low positive absorption efficiencies for total organic material are found with Syringodium filiformis Kützing and Sargassum sp. as food. Absorption efficiencies of the sea urchin Strongylocentrotus purpuratus (Stimpson) (calculated from the literature) were much greater than those of Lytechinus for carbohydrate, but less for protein and lipid. Both sea urchins showed negative efficiencies for some nutrient fractions of their foods. The absorption index (mg nutrient fraction absorbed/g dry wt ingested) showed that Thalassia supplied the most protein and total organic material (43 mg/g dry wt ingested and 142 mg/g dry wt ingested, respectively). In general, the absorption indices indicate that Lytechinus obtains more protein and lipid, but less carbohydrate from its food than does Strongylocentrotus. In the field Lytechinus has primarily a detrital diet.     

PRODUCTIVITY AND COMPOSITION OF A BALDCYPRESS-WATER TUPELO SITE AND A BOTTOMLAND HARDWOOD SITE IN A LOUISIANA SWAMP

The productivity and composition of two study sites in a southern Louisiana freshwater swamp were studied from October 1973 to November 1974. Net productivity was determined from measurements of litter-fall, stem growth of woody species, and harvest samples of annual herbaceous understory. Annual stem growth was calculated from biomass estimates on two different dates. The annual increase in stem biomass was 800 g dry wt/m² for a bottomland hardwood site (BLH) and 500 g dry wt/m² for a baldcypress-water tupelo site (CT). Litter-fall was 574 g dry wt/m²/yr for BLH and 620 g dry wt/m²/yr for CT. Harvest samples within the two plots yielded 200 g dry wt/m² and 20 g dry wt/m² for BLH and CT, respectively. Minimum net primary production was calculated as the sum of the three: 1574 g dry wt/m²/ yr for BLH and 1140 g dry wt/m²/yr for CT. Maximum estimates of herbaceous production and insect consumption were made by using values from the literature. Estimated total net primary productivity was 1733 g dry wt/m²/yr for BLH and 1516 g dry wt/m²/yr for CT. Tree composition was determined by the point-centered quarter method. Relative frequency, relative density, absolute density, relative dominance, and importance value (IV) were calculated for the tree species along each transect. In the bottomland hardwood area many woody species exist with Acer rubrum var. drummondii (IV = 23.9) and Nyssa aquatica (IV = 18.4) the most dominant. In the baldcypress-water tupelo area, fewer woody species exist and Taxodium distichum (IV = 39.2) and N. aquatica (IV = 37.6) dominated. Comparison of productivity data from several southeastern swamps indicate that flowing water regimes tend to result in the highest swamp forest productivity.     

Alterations in cerebrospinal fluid glycerophospholipids and phospholipase A2 activity in Alzheimer's disease

Our aim is to study selected cerebrospinal fluid (CSF) glycerophospholipids (GP) that are important in brain pathophysiology. We recruited cognitively healthy (CH), minimally cognitively impaired (MCI), and late onset Alzheimer''s disease (LOAD) study participants and collected their CSF. After fractionation into nanometer particles (NP) and supernatant fluids (SF), we studied the lipid composition of these compartments. LC-MS/MS studies reveal that both CSF fractions from CH subjects have N-acyl phosphatidylethanolamine, 1-radyl-2-acyl-sn-glycerophosphoethanolamine (PE), 1-radyl-2-acyl-sn-glycerophosphocholine (PC), 1,2-diacyl-sn-glycerophosphoserine (PS), platelet-activating factor-like lipids, and lysophosphatidylcholine (LPC). In the NP fraction, GPs are enriched with a mixture of saturated, monounsaturated, and polyunsaturated fatty acid species, while PE and PS in the SF fractions are enriched with PUFA-containing molecular species. PC, PE, and PS levels in CSF fractions decrease progressively in participants from CH to MCI, and then to LOAD. Whereas most PC species decrease equally in LOAD, plasmalogen species account for most of the decrease in PE. A significant increase in the LPC-to-PC ratio and PLA₂ activity accompanies the GP decrease in LOAD. These studies reveal that CSF supernatant fluid and nanometer particles have different GP composition, and that PLA₂ activity accounts for altered GPs in these fractions as neurodegeneration progresses.     

Chemical composition and antioxidant activities of Jeddah corniche algae,Saudi Arabia

The increased use of natural product in the pharmaceutical industry has led to an increase in demand for screening for bioactive compounds in marine algae. An important economic algae, through chemical composition analysis and their antioxidant activities were investigated in this study. Chemical composition analysis of three algal samples from the Chlorophyta Ulva lactuca (U), Phaeophyta Sargassum crassifolia (S) and Rhodophyta Digenea simplex (D) was tested. Main components were sugars (57.40–185.13 mg/g dry weight), uronic acids (29.3–45.26 mg/g dry weight), sulfate (94.7–181.2 mg/g dry weight), amino acids (7.6–16.7 mg/g dry weight) and small amounts of betaines (2.38–8.47 mg/g dry weight). Hydrolyzed chemical composition analysis fractions of algal extract was shown a great proportion of sugars plus sulfate (as polysaccharide composed) ranges between 332 and 538.2 mg/g dry weight with trace amounts of uronic acids (⩽9%). All three algal extract showed antioxidant activities on lipoxygenase, DPPH and on Ames test. Two of aqueous extracts (U and D) inhibited lipoxygenase activity by less than 50%, where as the methanolic extract (S) caused 76% inhibition of the control. In all cases, the methanolic extract were more inhibitory than the aqueous extract. The (S) showed the highest antioxidant activity with DPPH (69%) in aqueous extract and in methanol extract with Ames test (85%). Both U and D showed antioxidant activity with DPPH in hexane by less of 25% where as in both aqueous and methanolic extracts by less than 50% of the control. Aqueous and methanolic extracts of U and D showed high inhibition by Ames test which caused 70% and 75% respectively. IR spectra of algal extracts (U; D and S) range from 1450 to 750 cm⁻¹ were very similar absorption band at 1430, 1370, 1250, 1130, 1110, 1050 and 1020 cm⁻¹. Absorption bands were due to uronic acids, glucosides and sulfate. The presence of sulfated polysaccharide material in the fractions UF2, DF2 and SF2 were found as cell wall storage of marine algae, confirmed by ¹³C NMR spectroscopy. It is concluded that the algal species probably have a different components and can be used in the activities of antioxidant enzymes as reduced the risks of enzymes. But the correlation between the chemical composition and antioxidant activities of algal extracts needs further investigation.Abbreviations: (U), Ulva lactuca; (S), Sargassum crassifolia; (D), Digenea simplex; DPPH, α-diphenyl-β-picrylhydrazyl; HPLC, high performance liquid chromatographic     

Carbon, nitrogen and caloric content of eggs, larvae, and juveniles of the walleye pollock, Theragra chalcogramma

Measurements of dry weight (wt), carbon (C), nitrogen (N) and calories were made on walleye pollock eggs (0.24 mg, 35.3% C, 8.3% N, and 4.6 kcal g⁻¹ dry wt), larvae (0.16 g, 42.9% C, 11.1% N and 5.1 kcal g⁻¹ dry wt) and juveniles (22.4 g, 47.2% C, 9.0% N and 5.6 kcal g⁻¹ dry wt). For juvenile fish (9–360 g wet wt) the measured values were related to dry weight and Fulton's condition factor index (CFI) by regression models. The CFI was a better predictor of body composition than dry weight. As CFI improved from a minimum starvation level of 0.42 to a maximum of 1.16, body caloric content, percentage C, and the C/N ratio increased (kcal g⁻¹ dry wt = 4.4 CFI + 1.7, percentage carbon = 49.7 CFI^0.5, C/N ratio = 5.0 CFI + 0.9), while percentage N and percentage ash decreased (percentage N =−3.5 CFI + 12.1; percentage ash = 9.1 CFI^−1.4). The results of this study suggest that seasonal C, N and caloric content of young pollock can be estimated from measurements of Fulton's condition factor index.     

Production of allantoin, rabdosiin and rosmarinic acid in callus cultures of the seacoastal plant Mertensia maritima (Boraginaceae)

A callus culture of the extreme halophyte seacoastal plant Mertensia maritima (Boraginaceae) was established from apical shoots of the plant using a modified Murashige and Skoog medium supplemented with 6-benzyladenine (0.5?mg/L) and ??-naphthaleneacetic acid (2.0?mg/L). Three main compounds, (?)-R-allantoin, (+)-rabdosiin and rosmarinic acid, were isolated from extracts of M. maritima calli by liquid chromatography and identified by ¹H and ¹³C NMR, UV, ECD and HPLC?CMS. Quantitative HPLC analysis showed that the calli produce (+)-rabdosiin (0.14% dry wt), rosmarinic acid (0.74% dry wt) and (?)-R-allantoin (3.7% dry wt). Allantoin was detected in plant cell cultures for the first time. All of these metabolites were also present in lower quantities in different parts of the plant. The presence of rabdosiin and rosmarinic acid, in combination with the skin-conditioning agent (?)-R-allantoin, represents a potentially useful novel composition for skin protection.     

Biochemical and calorific content of deep-sea aspidochirotid holothurians from the northeast atlantic ocean

• 1.1. The organic composition of the body tissues of eight species of deep-sea aspidochirotid holothurian, collected between 500 and 4100m depth in the NE Atlantic Ocean, was obtained by the biochemical analysis of protein, lipid, carbohydrate and % ash.
• 2.2. The major organic class was protein with soluble lipid the major soluble fraction in the ovary. Carbohydrate values were consistently low.
• 3.3. The calorific value was significantly higher in the ovary than in the other tissues.
• 4.4. The total body calorific content for two selected species, Benthothuria funebris and Mesothuria lactea, was 25.62 and 26.24J/mg ash-free dry weight (AFDW).

     

Partitioning of oxygen consumption between “maintenance” and “growth” in developing herring Clupea harengus (L.) embryos

Growth and oxygen consumption was measured in developing herring Clupea harengus (L.) embryos. By considering the variations in oxygen consumption with embryonic size and growth rate, an attempt was made to partition oxygen consumption between growth related and growth unrelated (i.e., “maintenance”) processes. The metabolic cost of growth was estimated as ≈ 150 ng O₂ · μg dry wt tissue formed⁻¹. This estimate compares favourably with the biochemical estimate of the costs of transport and net biosynthesis. The “maintenance” component was proportional to embryonic mass (77 ng O₂ · μg⁻¹· d⁻¹). Over the entire embryonic period, growth processes were responsible for ≈ 25% of the cumulated oxygen consumption.     

Chemical defense,biochemical composition and energy content of three shallow-water Antarctic gastropods

Summary Aqueous extracts of the mantle tissues of the opisthobranchs Austrodoris kerguelensis and Tritoniella belli and the lamellarid gastropod Marseniopsis mollis were cytotoxic to the sperm of the antarctic sea urchin Sterechinus neumayeri, and caused behavioral responses (sustained terminal sensory tube-feet retractions) in five species of antarctic sea stars. Pieces of mantle tissue of all three species were noxious to two species of antarctic fish. Primary body components (mantle, foot, viscera) of the three gastropod species contained high levels (% dry wt) of NaOH-insoluble protein (40–59%), moderate levels of NaOH-soluble protein (7–25%) and lipid (6–18%), and low levels of carbohydrate (< 1%). The energetic composition of the tissues reflected their organic make-up, with most energy (11–17 kJg^–1 dry wt) associated with protein. Total energy contents of representative adult individuals were 192,26 and 69 kJ for A. kerguelensis (93 g wet wt), T. belli (22 g wet wt) and M. mollis (114 g wet wt), respectively. Although these sluggish gastropods lack an external shell and are nutrient-and energy-rich and therefore high quality prey, like many of their temperate and tropical counterparts, they appear to be protected by chemicals.     

Resistance of Pteridium aquilinum to attack by non-adapted phytophagous insects

Fresh bracken Pteridium aquilinum L. Kühn or crude bracken extracts deterred 9 non-adapted phytophagous insect species from feeding or settling. Feeding deterrent activity to 5 out of 7 insect species was present in crude bracken extracts at all times over the growing season and was significantly highest in May. Sequential isolation and purification of deterrents indicated that the sesquiterpene pterosin F (6-chlorethyl-2,5,7-trimethyl-indan-1-one) occurred in sufficiently high concentrations in late May/early June bracken frond (24–28 mg/kg fresh wt) to be partially responsible for the deterrent effects of crude bracken extracts to two insect species. A number of other fractions had feeding deterrent activity, but these were not characterized or quantified.     

The bioavailability of various selenium compounds to a marine wading bird

The uptake of dietary selenium (about 3.5 mg/kg AF dry wt) as selenomethionine, selenocystine, selenite, selenate, and fish selenium in the plasma and red blood cells (RBC) of the oystercatcher has been investigated. The birds received the various selenium compounds subsequently, for at least 9 wk. After dietary supplementation of selenocystine, selenite, and selenate, plasma selenium was about 350 μg/L and RBC selenium 2.1 mg/kg dry wt. After supplementation of selenomethionine, the plasma concentration increased to 630 μg/L, and the RBC concentration to 4.1 mg/kg dry wt. When the fodder contained 3.1 mg/kg fish Se, an average plasma and RBC concentration of 415 μg/L and 14.4 mg/kg dry wt, respectively, was measured. The maximal increase of the selenium concentration in the plasma was attained at first sampling, 14 d after a change in dietary selenium (selenomethione or fish Se); the uptake seemed to be a concentration-regulated process. RBC concentrations (γ in mg/kg dry wt) increased with time (X in d) according toY=a?be^?cX . Fifty percent of the total increase was attained within 17d, suggesting that diffusion into the RBC played a role. The selenium concentration in the plasma was positively correlated with the (fish) Se concentration in the fodder; the RBC concentration (60 d after the change in diet) was positively correlated with the plasma concentration. When the diet contained fish Se, the blood selenium concentrations of the captive birds were similar to the concentrations measured in field birds. Fish Se is a yet undetermined selenium compound. The present experiment showed that fish Se differed from selenomethionine, selenocystine, selenite, or selenate in uptake from the food and uptake in the RBC.     

Biochemical effects of fenbensazole on Hymenolepis diminuta in vivo

An investigation of the chemotherapeutic and biochemical effects of a new broad-spectrum anthelmintic, fenbendazole, (FBZ, methyl 5-[phenylthio]-benzimadazole-2-carbamate), on Hymenolepis diminuta in experimentally infected rats is reported. FBZ proved to be highly active against H. diminuta; a single oral dose of 12.5, 25 and 50 mg/kg body wt. on day 15 of infection eliminated 77, 100 and 88% of the tapeworms respectively as determined at necropsy 24 h after treatment. The chemotherapeutic actions of FBZ on H. diminuta in vivo were accompanied by marked changes in worm wt. and chemical composition. Tapeworms recovered from rats that had received a therapeutically effective dose of FBZ 18 h earlier were significantly smaller and contained much less glycogen (as a percent of the fresh wt.) than worms from unmedicated controls. Protein concentrations rose in FBZ-treated worms, but more slowly than the rate of decline in glycogen concentration. Glycogen/protein ratios in FBZ-treated worms were considerably lower than the corresponding control values. Differences in the absolute amounts of glycogen and protein between control and drug-treated worms were even more profound. Administration of a single oral dose of FBZ (14 mg/kg) to the rat produced in H. diminuta another change, the onset of which coincided with, or preceded, the gross alterations in worm wt. and chemical composition. In vitro studies, carried out 16 h after treatment, revealed that FBZ-treated worms absorbed and metabolized much smaller quantities of exogenous glucose than did the controls, and the ability to the worm to accumulate glucose against a concentration difference was significantly depressed.     

Heterocyclic aromatic amine content of selected beef flavors

Previous work has shown that meat extracts contain potent mutagenic and/or carcinogenic heterocyclic aromatic amines (HAAs). Because meat extracts and some beef flavors are produced from similar precursors and processing steps, the beef flavors may also contain HAAs. This study analyzed 24 commercial beef flavors and 2 food-grade beef extracts for creatine and creatinine concentrations, mutagenic activity and HAA concentrations (IQ, MeIQ, MeIQ_x, DiMeIQ_x, Glu-P-1, Glu-P-2 and PhIP). The creatine and creatinine levels of the flavors ranged from 0 to 73 and from 0 to 21 mg/g (dry wt.), respectively. The mutagenic activities of the flavors ranged from 0 to 3200 Salmonella typhimurium TA98 revertants/g (dry wt.). No direct relationship was found between creatine and/or creatinine concentrations and mutagenic activities. However, flavors with high creatine (> 1.5 mg/g) or creatinine (> 2 mg/g) levels exhibited higher mutagenic activities than did flavors with low levels of these compounds. Flavors with high mutagenic activities (> 1500 revertants/g) contained measurable amounts of HAAs. Three flavors contained MeIQ_x (7.2–21.2 ng/g [dry wt.]) and one contained DiMeIQ_x (4.2 ng/g [dry wt.]).     

Distribution of acid and vanadium in Rhopalaea birkelandi Tokioka

The distribution of acidity, vanadium, and fouling in Rhopalaea birkelandi Tokioka, a solitary ascidian common on the Pacific coast of Central America, was investigated. The tunic around the siphons released acid (pH ?2) when slightly bruised and was not fouled. However, the basal parts of the tunic, which were non-acidic, were fouled. Whole R. birkelandi has ≈610 ppm vanadium dry wt; the zooid with the tunic removed has ≈ 1956 ppm and the tunic has ≈ 500 ppm vanadium dry wt. Vanadocytes were present. These data are discussed in reference to previous work on the roles of vanadium and acid in benthic ascidians.     

Stable constitution of artificial oil body for the refolding of IGF1

Over-expression of oleosin-fused IGF1 results in the formation of insoluble aggregates in Escherichia coli occupying 35% of total proteins. In this study, a method based on artificial oil body (AOB) was applied to obtain active IGF1, insulin-like growth factor 1, from its insoluble form in one step. The stability of AOB emulsions constituted with soybean oleosin was maximized in the optimal composition of TAG (97.04%, wt/wt), PL (1.14%, wt/wt), and oleosin-UbIGF1 (1.82%, wt/wt) at pH 7.5 and at 25°C. Upon sonication, the mixture comprising plant oil and the insoluble fusion protein was readily assembled into AOBs. After peptide cleavage mediated by endopeptidase, the IGF1 free of fusion tags was liberated and then recovered. Subsequently, IGF1 self-refolded on AOB was obtained with high yield of 63.2 mg/g dry cell. This on-AOB refolding can be applied to the development of bacterial expression and purification of other active recombinant proteins.