Modified ��-cyclodextrins as prospective agents for improving water solubility of organic pesticides

The drawback of some organic pesticides is their low water solubility. Cyclodextrins are used as agents for improving pesticides water solubility. However, the stabilization of the crystalline lattice can reduces to a large extent the solubility of cyclodextrins, especially β-cyclodextrin. Here, searching for the water soluble β-cyclodextrin derivatives, a set of new “host” compounds were prepared by the reaction of β-cyclodextrin with methyl epoxycinnamate. The reactants ratio was varied in to study the substitution degree of the obtained derivatives. The structure was determined by the ¹H-NMR and FT IR spectra. The average degree of substitution was determined by integration of the corresponding NMR signals and by elemental analysis. The solubility of four selected pesticides: dimethoate, simazine, linuron and thiram, in water with and without addition of the new modified β-cyclodextrin was measured by ultraviolet spectrophotometry. Our results showed that the modified β-cyclodextrins significantly improve solubility of pesticides.     

Microcystin-LR biodegradation by Sphingopyxis sp. USTB-05

A promising bacterial strain for biodegrading microcystin-LR (MC-LR) as the sole carbon and nitrogen source was successfully isolated from Lake Dianchi, China. The strain was identified as Sphingopyxis sp. USTB-05, which was the first isolated MCs-biodegrading Sphingopyxis sp. in China. The average biodegradation rate of MC-LR by Sphingopyxis sp. USTB-05 was 28.8 mg??L^?1 per day, which was apparently higher than those of other bacteria reported so far. The optimal temperature and pH for both strain USTB-05 growth and MC-LR biodegradation were 30??C and 7.0, respectively. The release of MC-LR from the cyanobacterial cells collected from Lake Guishui and the biodegradation of MC-LR by both strain and cell-free extract (CE) were investigated. The results indicated that MC-LR with the initial concentration of 4.0 mg??L^?1 in water was biodegraded by Sphingopyxis sp. USTB-05 within 4 d, while MC-LR with the initial concentration of 28.8 mg??L^?1 could be completely removed in 3 h by CE of Sphingopyxis sp. USTB-05 containing 350 mg??L^?1 protein. During enzymatic biodegradation of MC-LR, two intermediate metabolites and a dead-end product were observed on an HPLC chromatogram. Moreover, the similar scanning profiles of MC-LR and its metabolic products indicate that the Adda side-chain of MC-LR was kept intact in all products.     

Preparation of reverse osmosis membrane with high permselectivity and anti-biofouling properties for desalination

• Nanoparticle incorporation and anti-biofouling grafting were integrated. • Flux of modified membranes was enhanced without rejection sacrificing. • Anti-biofouling property of modified membranes was improved. High performance is essential for the polyamide (PA) reverse osmosis (RO) membranes during the desalination process. Herein, RO membranes with high permselectivity and anti-biofouling properties were fabricated by nanoparticles incorporation and anti-biofouling grafting. Hydrotalcite (HT) incorporation was performed with a dual role, enhancing water flux and acting as grafting sites. The HT incorporation increased the water flux without sacrificing the salt rejection, compensating for the loss caused by the following grafting reaction. The exposed surface of HT acted as grafting sites for anti-biofouling agent dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride (DMOTPAC). The combination of HT incorporation and DMOTPAC grafting endowed RO membranes with high permselectivity and anti-biofouling properties. The water flux of the modified membrane PA-HT-0.06 was 49.8 L/m²·h, which was 16.4% higher than that of the pristine membrane. The salt rejection of PA-HT-0.06 was 99.1%, which was comparable to that of the pristine membrane. As to the fouling of negatively charged lysozyme, the modified membrane’s water flux recovery was superior to that of the pristine membrane (e.g. 86.8% of PA-HT-0.06 compared to 78.2% of PA-pristine). The sterilization rates of PA-HT-0.06 for E. coli and B. subtilis were 97.3% and 98.7%, much higher than those of the pristine membrane (24.0% for E. coli and 26.7% for B. subtilis).     

藻类与有机污染物间的相互作用研究

本文就若干有机污染物对藻类的毒性效应及藻类对这些污染物的富集降解作用进行了系列研究。结果表明，不同污染物对藻类的毒性有很大差别，其中三有机锡的毒性最大。此外，不同藻类对毒物具有不同的敏感性，其中扁藻Platymonas sp.和斜生栅藻S．obliquus最敏感。藻类通过生物富集和生物降解两种途径去除水中污染物，其中，邻苯二甲酸二丁酯最容易被去除。藻类固定化能够在一定程度上增加藻类对污染物的降解。     

Temperature and salinity tolerances of embryos and larvae of the deep-sea mytilid mussel ��Bathymodiolus�� childressi

We examined temperature and salinity tolerances of early embryonic and larval stages of the deep-sea, cold-seep mussel ??Bathymodiolus?? childressi to determine whether they may control the dispersal depth of larvae. Salinity and temperature tolerances increased with developmental stage, but tolerance ranges were not as wide for the larvae of ??B.?? childressi as for the larvae of the related shallow-water mussel Mytilus trossulus. Normal development occurred in ??B.?? childressi from 7 to 15°C and at salinities of 35 and 45. Greater tolerance of ??B.?? childressi embryos to high than low salinities may aid development of negatively buoyant early embryos at brine seeps. Although there was a decreasing trend in survival of ??B.?? childressi larvae with increasing temperature, survival of ??B.?? childressi trochophores was not significantly different at 20°C than at the adults?? ambient temperature. Since larvae tolerate increasing temperatures as they age and seawater temperatures at 100?m depth do not exceed 20°C in months following the mussels?? spawning season, we suggest that temperature would not limit vertical migration of the veliger larvae of ??B.?? childressi into even the uppermost layer of the water column above the cold seeps in the Gulf of Mexico.     

Effects of autotomy on long-term survival and growth of painted spiny lobster (Panulirus versicolor) on the Great Barrier Reef, Australia

The effects of autotomy (shedding of appendages) on survival and growth rates of painted spiny lobster were investigated at Northwest Island (23^° 18?? S, 152^° 43?? E) during the period 2003?C2006. Adult lobsters were captured, tagged, and classified as either uninjured (n?=?68), minimally injured (n?=?39) or moderately injured (n?=?19) depending on the number and type of appendages that were autotomized during capture and handling. Six to thirty-six months after release, 86 lobsters were recaptured (mean time at large?=?305?days). Recapture rates of uninjured (64.7%), minimally injured (71.8%), and moderately injured lobsters (73.7%) were not significantly different. Similarly, mean annualized growth rates of uninjured, minimally injured, and moderately injured lobsters were not significantly different. This suggests that the energetic cost of a single episode of autotomy is either negligible or exists as a trade-off with some other life history trait, such as reduced reproductive performance. These results support the use of certain management tools (e.g., size limits) that prescribe release of non-legal lobsters, regardless of their injury status.     

Effects of salinity and dietary DHA (22:6n - 3) content on lipid composition and performance of Penaeus kerathurus postlarvae

A two-way ANOVA experiment was designed to study the effects of salinity and dietary docosahexaenoic acid (DHA; 22:6n-3) on lipid composition and performance of postlarvae from the marine shrimp Penaeus kerathurus (Forskål, 1775). Shrimp were reared from 1- to 8-d-old postlarvae at 35 and 25‰S with Kelko-enriched Artemia sp. [20.0 μg (n-3)?HUFA mg^?1 dry weight; 9.1 μg DHA mg^?1 dry weight] and nonenriched Artemia sp. [14.2 μg (n-3)?HUFA mg^?1 dry weight; 0.3 μg DHA mg^?1 dry weight]. Dietary DHA content did not affect either total length or survival but influenced the nutritional status represented by condition indices (triacylglycerol/total polar lipid and triacylglycerol/free cholesterol) of 8-d-old postlarvae at the end of the experiment. Culture salinity affected final total length and condition indices but did not show any effect on survival in the different experimental treatments. The interaction of dietary DHA and culture salinity was not significant for total length and survival but was significant for both condition indices used. P. kerathurus 8-d-old postlarvae showed better growth, survival and nutritional condition when reared at 35‰S and when fed on Kelko-enriched Artemia sp., but the differences with postlarvae from other treatments were very poorly marked. The results demonstrate that 8-d-old postlarvae may have sufficiently developed osmoregulatory capabilities to resist 25‰S under good conditions, although (n-3) HUFA-enriched diets may also enhance osmotic stress resistance, general performance and disease resistance.     

Professor Casu’s contribution to cyclodextrins,the remarkable cage-shaped molecules: a review

Cyclodextrins are cage-shaped molecules having the remarkable ability to trap smaller compounds, and have thus led to applications in many disciplines such as medicine to increase the bioavailability of hydrophobic drugs. This historical review summarizes the outstanding contribution of the late Professor Benito Casu to cyclodextrin research and, more generally, to the chemistry and biochemistry of linear and cyclic oligosaccharides, polysaccharides, glycosaminoglycans, and heparin. Professor Casu was the first to elucidate the structure and conformations of cyclodextrins by infrared spectroscopy and proton nuclear magnetic resonance (NMR). In particular, he showed that trapped compounds induced a shift of H peaks in NMR due to the shielding effect of cyclodextrins. He also demonstrated that the d-glucopyranose cyclodextrin units are in the C-1 chair conformation by analyzing α-cyclodextrin by NMR in dimethylsulfoxide-d₆.

     

Copper and zinc interaction on water clearance and tissue metal distribution in the freshwater mussel, Cristaria plicata, under laboratory conditions

Copper and zinc interaction on clearance from water and distribution in different tissues was investigated for the freshwater mussel, Cristaria plicata, under laboratory conditions. Clearance rate of Cu or Zn from water was highly dependent on exposure concentration. Interaction effect was most evident at 300 ??g??L^?1 Cu exposure and depressed the Zn clearance rate significantly (p<0.05). However, the presence of 100 ??g??L^?1 and 300 ??g??L^?1 Zn hardly affected the Cu clearance rate. The 300 ??g??L^?1 Cu presence enhanced Cu accumulation in each tissue most significantly (p<0.01), but caused Zn content to decrease in the gills by 62% (p<0.05), viscera by 49% (p<0.05) and foot by 31% (p<0.05), and increase in the mantle by 97% (p<0.05) and the muscles by 243% (p<0.05) for different Zn exposure treatments. The response of metal accumulation in various tissues of the test mussels indicated that Zn transferred from the gills, viscera and foot to the mantle and muscles might be one of the important characteristics of the Zn regulatory mechanism by leading to a narrow range of Zn concentration in the different tissues.     

Joint effects of Penta-BDE and heavy metals on Daphnia magna survival, its antioxidant enzyme activities and lipid peroxidation

The joint toxicity of Penta-BDE (Pe-BDE) and heavy metals including cadmium and copper on Daphnia magna (D. magna) was evaluated on the basis of determining the 48 h survival, antioxidative enzyme responses, and lipid peroxidation. The response was classified as additive, greater than additive, or less than additive by comparing the measured ??toxic units, TU?? with one. Based on the survival of D. magna, less-than-additive interactions were found in most of mixtures treatments. This may be attributed to the different toxicity mechanism between Pe-BDE and metals. Cu and Cd played a greater role in toxicity than what Pe-BDE did. As for the superoxide dismutase (SOD) and catalase (CAT) activity, most response was less than additive. For the glutathione S-transferases (GST) activity, most of the greater-thanadditive responses were found in the Cu plus Pe-BDE treatments, but the additive responses occurred in Cd plus Pe-BDE treatments and binary metal treatments. For lipid peroxide levels, which were measured as malondialdehyde (MDA) levels, less-than-additive response occurred in the 50% Cd plus 50% Cu and ternary mixture treatments. Results suggested that Pe-BDE, Cd, and Cu could induce different patterns of antioxidant enzyme responses, such as antioxidant/prooxidant responses, depending on their capability to produce reactive oxygen species and antioxidant enzymes to detoxify them.     

Extent and nature of extracellular organic production by the marine coccolithophorid Hymenomonas carterae

Production of extracellular dissolved organic substances by cultures of the marine coccolithophorid Hymenomonas carterae SMBA 254 was investigated by the ¹⁴C-tracer technique. In 4 h incubations, extracellular ¹⁴C production represented 20 to 64% of ¹⁴C incorporation into cell material for cultures nearing, or during stationary growth; for rapidly growing cultures with relatively low cell densities the ¹⁴C-production was only 4 to 10% of incorporation. Intra-and extra-cellular material was fractionated by ion-exchange membrane electrodialysis. Ionic compounds accounted for 40 to 60% of extracellular material; in contrast only 16 to 27% of intracelular metabolites were in this category. Of a range of methods which were investigated, separation of compounds by gel-filtration in conjunction with two-dimensional thin-layer chromatography proved most effective. Up to 80% of extracellular material was of less than 1 800 mol. wt and included carbohydrates and amino acids, with glutamic acid predominating. The intracellular material was more heterogeneous, with a substantially greater proportion of high molecular weight material. The quite distinct compositions show clearly that extracellular production observed in these experiments arose through excretion and was not attributable to cell lysis.     

SETAC GLB — Gründung und Entwicklung

Goal, Scope, and Background

In the context of the ISO-standardisation of the in vitro micronucleus test for (waste) water testing (ISO/DIS 21427-2), a national collaborative study was organized by the German Federal Institute of Hydrology (BfG) involving ten laboratories of private companies, universities and public authorities. The formation of micronuclei (MN) is a special kind of chromosomal aberration. To meet the standardisation requirements for this method, encoded waste water samples, some of them spiked with known genotoxins, had to be tested in a collaborative study. The study should demonstrate practicability of the in vitro micronucleus test for waste water testing and should provide validity data.

Material and Methods

The micronucleus assay was performed with the permanently growing Chinese hamster lung fibroblast cell line V79. Four encoded samples from one municipal and one industrial wastewater treatment plant were tested with and without metabolic activation by S9-mix. Two of these samples were spiked in advance with defined concentrations of the clastogenic substances cyclophosphamide and mytomycin C. The defined assessment criterion for genotoxicity was the lowest dilution of a sample that does not show any significant induction of micronuclei (LID; lowest ineffective dilution). Cytotoxicity was judged by determining the survival-index, i.e. the percentage growth rate of the cells compared with the respective negative controls. As supplementary qualitative criteria, the mitotic index and the proliferation index were assessed.

Results

Although some of the laboratories had little or even no experience with the protocol of the in vitro micronucleus test described in the ISO-draft, all participants suceeded in establishing the assay within few weeks and in generating viable test results. The two nongenotoxic samples were detected as negative by 90% or 100% of the participants. The mitomycin C-spiked sample (expected to be positive without S9 supplementation) was correctly evaluated as positive by all laboratories. The cyclophosphamide-spiked sample (expected to be positive with S9 supplementation) was evaluated correctly as genotoxic by 80% of the laboratories. A post-test analysis found evidence that the false-negative results were due to technical failure, but not of a methodological nature. The sample LID values varied by no more than one dilution step around the median LID-value for all samples investigated. The survival index was proven to be a robust measure for estimation of cytotoxicity.

Discussion

The measurement of micronuclei is an important parameter for the detection of cytogenetic damage. In contrast to the single-cell gel electrophoresis assay (Comet assay), which is used as an indicator test, the in vitro micronucleus test detects non-repairable and thus manifested genetic damage. Consequently, the in vitro micronucleus test can be regarded as the more significant test system. A more frequent occurrence of micronuclei in treated cells suggests a risk of severe genetic damage for subsequent cell generations. In the interest of a precautionary environmental protection and health protection no municipal or industrial waste-water samples should show any significant induction of micronuclei in the treated cell populations.

Perspectives

The presented collaborative study was the first interlaboratory comparison of the in vitro micronucleus test using wastewater samples. The test system is intended to complement the already DIN- and ISO-standardised bacterial tests, i.e. the umu-test and the Ames plate incorporation assay. The data generated in the course of this project justify the transformation of the draft standard into the final draft international standard (FDIS), the preliminary stage of an international norm, so that a valid, standardised test system for the detection of cukaryotic genotoxicity in water samples might become available.     

Measurements of electron transport activities in marine phytoplankton

A simple and sensitive spectrophotometric method of measuring electron transfer in the transport system (ETS) in marine phytoplankton has been developed and characterized. The assay is based on the reduction of the tetrazolium salt 2-(p-iodophenyl)-3-(p-nitrophenyl)-5-phenyl tetrazolium chloride (INT) by homogenates in the presence of the nonionic detergent Triton X-100. The simplicity and sensitivity of this assay have considerable advantage over existing methods of measuring ETS activity in marine samples where numerous assays must be rapidly carried out on samples which often demonstrate low activities. Several established substrates and inhibitors of electron transport in the ETS were investigated, and each is discussed in relation to the site of INT reduction in the diatoms Skeletonema costatum and Chaetoceros debilis and in the unicellular green alga Dunaliella tertiolecta. The results from these studies suggest that the maximum rate of electron transport, V _max, is measured in each case.     

Sustainable fishing gear: the case of modified circle hooks in a Costa Rican longline fishery

Our research aims to identify longline fishing gear modifications that can improve fishing selectivity and reduce incidental capture of non-target species. Catch rates and anatomical hook locations (AHL) were compared when using a 14/0 standard ??control?? circle hook with a 0° offset and an experimental ??appendage?? hook in a Costa Rican longline fishery. With the appendage, the maximum dimension of the appendage hook was increased by 10% and the minimum dimension of the hook by 19%. A total of 1,811 marine animals were captured during five fishing trips. By taxonomic groups, sea turtles represented the largest total catch (27%), followed by sharks (26%), rays (25%), mahimahi (Coryphaena hippurus) (12%), and tunas and billfish (10%). Non-target and discard species, such as rays and sea turtles, accounted for over half of the total catch. Catch per unit effort (CPUE; number of individuals per 1,000 hooks) was higher with control hooks compared to appendage hooks for all species?? categories except rays; appendage hooks caught 52% fewer sea turtles and 23% fewer tunas and billfish than standard hooks, which represents a significant reduction in bycatch of endangered and other species. No differences were found in the AHL for sea turtles, suggesting use of the appendage may not incur additional advantages regarding turtles?? post-release survivorship. Despite lower catch rates for marketable species, such as sharks and mahimahi, use of the appendage resulted in dramatic reductions in catch rates of sea turtles. The results suggest that large scale adoption of hooks with a significantly wider hook dimension could be an effective conservation measure to maintain marine biodiversity while allowing for continued fishing.     

Ingestion and incorporation of coral-mucus detritus by reef zooplankton

The copepod Acartia tonsa and the reef mysid Mysidium integrum ingest stained coral mucus. Ingestion rates determined with radioisotope-labeled mucus ranged from 4 to 81% body carbon · 24 h^-1 for the copepods and I to 70% body carbon · 24 h^-1 for the mysids. Incorporation was measured by comparing the organic composition of fecal material and by the incorporation of isotope-labeled mucus. A. tonsa incorporated 47% of ingested ash-free material, 68% of carbon and 36% of nitrogen. M. integrum incorporated 44% of ingested ash-free matter, 57% of carbon and 55% of nitrogen. Incorporation estimates using ¹⁴C-labeled mucus were 65% and 39% for incorporation by A. tonsa and M. integrum respectively. A. tonsa and M. integrum incorporated both the mucus substrate and the epiphytic bacteria of the mucus-detritus.     

Selection and characterization of eight freshwater green algae strains for synchronous water purification and lipid production

The objective of this study is to select and characterize the candidate for synchronous water purification and lipid production from eight freshwater microalgae strains (Chlorella sp. HQ, C. emersonii, C. pyrenoidosa, C. vulgaris, Scenedesmus dimorphus, S. quadricauda, S. obiquus, Scenedesmus sp. LX1). The strains Chlorella sp. HQ, C. pyrenoidesa, and S. obliquus showed superiority in biomass accumulation, while the top biomass producers did not correspond to the top lipid producers. S. quadricauda achieved higher lipid content (66.1%), and Chlorella sp. HQ and S. dimorphus ranked down in sequence, with lipid content above 30%. Considering nutrient removal ability (total nitrogen (TN): 52.97%; total phosphorus (TP): 84.81%), the newly isolated microalga Chlorella sp. HQ was the possible candidate for water purification coupled with lipid production. To further investigate the lipid producing and nutrient removal mechanism of candidate microalga, the ultra structural changes especially the lipid droplets under different water qualities (different TN and TP concentrations) were characterized. The results elucidate the nutrient-deficiency (TN: 3.0 mg·L^–1; TP: 0.3 mg·L^–1) condition was in favor of forming lipid bodies in Chlorella sp. HQ at the subcellular level, while the biomass production was inhibited due to the decrease in chloroplast number which could further suppress the nutrient removal effect. Finally, a twophase cultivation process (a nutrient replete phase to produce biomass followed by a nutrient deplete phase to enhance lipid content) was conducted in a photo-bioreactor for Chlorella sp. HQ to serve for algae-based synchronous biodiesel production and wastewater purification.     

Effect of diet and paralarval development on digestive enzyme activity in the cephalopod <Emphasis Type="Italic">Robsonella</Emphasis><Emphasis Type="Italic">fontaniana</Emphasis>

This study aims at establishing the maturation of the digestive system in Robsonella fontaniana by means of measuring the digestive enzyme activity in paralarvae after hatching. Different groups of newly hatched paralarvae were fed with Artemia sp. (FA), Lithodes santolla zoea (FL) or were starved to serve as negative control (ST), the experimental period lasted 27 days after hatching (DAH). The semi-quantitative assay api^® ZYM (bioMérieux, France) was used to identify the pool of digestive enzymes present in paralarvae prior to selecting the specific enzymes acid phosphatase, total protease, trypsin and chymotrypsin for analysis. Mortality and larval protein content were also measured during the experiment. The survival of R. fontaniana hatchlings differed depending on the quality of the diet offered (ST < FA < FL), the same trend was observed with respect to paralarval protein content. Total protease and acid phosphatase activities were not related to either time of development or diet (P < 0.05). However, the activity of trypsin and chymotrypsin after DAH 10 was dependent on diet (P < 0.05). Paralarvae fed with Lithodes zoea (FL) performed better than paralarvae in the other two groups, exhibiting lower mortality, higher protein content and the highest proteolytic activity for trypsin and chymotrypsin. The results indicate that Lithodes-larvae are a better diet for R. fontaniana paralarvae than Artemia sp.     

Microalgae cultivation and culture medium recycling by a two-stage cultivation system

Nutrients and water play an important role in microalgae cultivation. Using wastewater as a culture medium is a promising alternative to recycle nutrients and water, and for further developing microalgae-based products. In the present study, two species of microalgae, Chlorella sp. (high ammonia nitrogen tolerance) and Spirulina platensis (S. platensis, high growth rate), were cultured by using poultry wastewater through a two-stage cultivation system for algal biomass production. Ultrafiltration (UF) or centrifuge was used to harvest Chlorella sp. from the first cultivation stage and to recycle culture medium for S. platensis growth in the second cultivation stage. Results showed the two-stage cultivation system produced high microalgae biomass including 0.39 g·L^–1Chlorella sp. and 3.45 g·L^–1S. platensis in the first-stage and second-stage, respectively. In addition, the removal efficiencies of NH₄⁺ reached 19% and almost 100% in the first and the second stage, respectively. Total phosphorus (TP) removal reached 17% and 83%, and total organic carbon (TOC) removal reached 55% and 72% in the first and the second stage, respectively. UF and centrifuge can recycle 96.8% and 100% water, respectively. This study provides a new method for the combined of pure microalgae cultivation and wastewater treatment with culture medium recycling.

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Optimizing rearing conditions of hatchling loliginid squid

Eggs laid by the California market squid (Loligo opalescens) were collected from spawning grounds and reared in the laboratory. The eggs were maintained in a rearing tank that was part of a closed, recirculating system. The system included seven 220-l circular tanks with attached filtration. Five experiments were conducted to test hatchling survival. One of them evaluated survival on three different food types: (a) enriched Artemia sp. nauplii, (b) wild zooplankton and (c) a mixture of a and b plus mysid shrimp. This mixture of food types (c) was offered to the hatchlings in the other four experiments. High mortality occurred in all experiments between days 1 and 15 post-hatching. However, survival over the entire time span of the experiments (45-60 days) was between 36% and 60%. These survival rates are well above previously reported survival rates for the same time period, and overall are up to 35% better than any survival results ever attained for the routine culture of Loligo spp. squid. Results suggest that high survival can be achieved by: (1) rearing hatchlings in a recirculating system consisting of small round tanks designed to maintain water quality and pH within narrow limits (8.1-8.4), (2) maintaining low current speed (1.0-1.4 cm s^-1) to reduce skin damage and to enhance hatchling-prey interactions, (3) increasing feeding rate by feeding small amounts of food at regular intervals (every 2-3 h) during day time hours and keeping prey densities above 50 prey l^-1, (4) feeding hatchlings with enriched Artemia nauplii during days 1-30 post-hatching and (5) feeding a variety of prey types and sizes to match the different sizes and hunting abilities of same-aged but heterogeneously developing hatchlings. The results from this study will enhance future culturing efforts for the commercially important loliginid squid.     

Carbon dioxide fixation by Chlorella sp. USTB-01 with a fermentor-helical combined photobioreactor

A promising microalgal strain isolated from fresh water, which can grow both autotrophically on inorganic carbon under lighting and heterotrophically on organic carbon without lighting, was identified as Chlorella sp. USTB-01 with the phylogenetic analysis based on 18S ribosomal ribonucleic acid (rRNA) gene sequences. In the heterotrophic batch culture, more than 20.0 g·L^?1 of cell dry weight concentration (DWC) of Chlorella sp. USTB-01 was obtained at day 5, and which was used directly to seed the autotrophic culture. A novel fermentor-helical combined photobioreactor was established and used to cultivate Chlorella sp. USTB-01 for the fixation of carbon dioxide (CO₂). It showed that the autotrophic growth of Chlorella sp. USTB-01 in the combined photobioreactor was more effective than that in the fermentor alone and the maximum DWC of 2.5 g·L^?1 was obtained at day 6. The highest CO₂ fixation of 95% appeared on day 1 in the exponential growth phases of Chlorella sp. USTB-01 and 49.8% protein was found in the harvested microalgal cells.