Evaluation of mixture effects in a crude extract of compost using the CALUX bioassay and HPLC fractionation

Potential synergistic interactions between polycyclic aromatic hydrocarbons in a household sewage sludge compost extract were investigated using the Dioxin-Responsive Chemical-Activated Luciferase gene eXpression (DR-CALUX) assay and reverse-phase high-performance liquid chromatography (RP-HPLC) fractionation. The biological activity of the crude extract was measured in vitro using the CALUX assay. The CALUX activity of the extract was as potent as 360-pg CALUX-TEQ (2,3,7,8-TCDD equivalent value) per g sample, this was 70 times above the WHO-TEQ value which was derived from chemical analyses of dioxins/furans and dioxin-like PCBs of the mixture. The CALUX activity pattern of the crude extract and the retention times of 26 polycyclic aromatic compounds (PACs), as determined by RP-HPLC on an octadecylsilica column, suggested that the dioxin-like compounds with the log K(OW) (n-octanol/water partition coefficient) values corresponding to 6.0-7.0 contributed highly to the whole activity. The CALUX activity of the crude extract was three times the sum of the CALUX activities of the RP-HPLC separated fractions. Mixture effects were assessed by co-exposure of each HPLC fraction and 2,3,7,8-TCDD to the cells. The four concentration levels of added 2,3,7,8-TCDD corresponded to the TEQ value in the original compost sample. The experimental CALUX activity was higher than the predicted CALUX activity for some fractions. It was demonstrated that some compounds in the compost sample interacted synergistically with 2,3,7,8-TCDD in terms of dioxin-like activity. This finding points out the necessity for detailed investigation of synergistic effects in environmental samples.     

Photoperiodic control of germination in the unicell Chlamydomonas

Photoperiodic time measurement is a well-documented adaptation of multicellular plants and animals to seasonal changes in the environment, but it is unclear whether unicellular organisms can exhibit bona fide photoperiodic responses. We demonstrate that the occurrence of zygospore germination of the unicellular alga Chlamydomonas is a genuine photoperiodic response. Germination efficiency is enhanced in long days as compared with short days. While the total amount of light exposure influences the efficiency of germination, the photoperiod is a significant cue for germination. The developmental stage that senses the photoperiod is just prior to mating and during the first days of zygospore development, so there may be a critical window of zygospore maturation that is regulated by photoperiod. Because zygospores are resistant to freezing injury, whereas vegetative cells are not, it is likely that the suppression of germination by short days is an adaptive response for overwintering of Chlamydomonas. Therefore, Chlamydomonas is a single-celled organism that is capable of photoperiodic responses.     

18S rRNA phylogeny of sea spiders with emphasis on the position of Rhynchothoracidae

The phylogenetic relationships among all living families of sea spiders (Arthropoda: Pycnogonida) are investigated using nearly complete 18S rRNA sequences from 57 ingroup species and five chelicerates under the Bayesian and maximum likelihood methods. Monophyly of Colossendeidae, Pycnogonidae, Phoxichilidiidae, Endeidae and Pallenopsidae is consistently supported. However, the genera formerly classified in the family Ammotheidae are split up into two distantly related groups. The genera Ascorhynchus and Eurycyde (here recognized as Ascorhynchidae) are possibly an early offshoot of sea spiders, whereas other ammotheids constitute a robust terminal clade with Pallenopsidae, Phoxichilidiidae and Endeidae. This topology also opposes the prevalent assumption of successive losses and simplification of three kinds of cephalic appendages like in a previous cladistic analysis. At least three independent losses are suggested for palps by the inferred topology, and both chelifores and female ovigers may have been lost twice. Our knowledge of early ontogeny and internal anatomy is more congruent with the present 18S rRNA data. The families Callipallenidae and Nymphonidae with unique “attaching larvae” are grouped together in present molecular trees, suggesting that extended paternal care of offspring evolved only once in Pycnogonida. Confident clustering of Pycnogonidae and Rhynchothoracidae indicates that the number of female genital pores is an evolutionary conservative character.     

Estrogen content and relative performance of Japanese and British sewage treatment plants and their potential impact on endocrine disruption.

Both the UK and Japan are densely populated islands with relatively short rivers. Therefore, both countries are likely to be highly exposed to contaminants emanating from their human populations. This review considered how effective the different sewage treatment facilities of the two countries are at removing steroid estrogens from the effluent. The methods of estrogen analysis in sewage effluent, the number and importance of different sewage treatment types, and their apparent effectiveness at removing estrogens were all considered. In both countries, the activated sludge treatment was dominant in terms of people served and water discharged. The analytical techniques used by those studying estrogen concentrations in effluents in both countries were broadly similar. Activated sludge plant (ASP) effluent in the UK typically contained around 2 ng/L estradiol (E2) and 8 ng/L estrone (E1), while Japanese ASPs typically reported E2 as below detection, and 10 ng/L E1 in their effluents. When estrogenic bioassays were used in Japan, they typically record an estrogenic potency of 10 ng/L E2 equivalents. Even taking into account ethinylestradiol (EE2) (not found in Japanese effluents), the overall estrogenicity of British sewage effluents would appear to be the same as that of Japanese sewage effluents (around 10 ng/L E2 equivalents). This suggests that the ASPs serving the large urban communities in Japan and the UK would have effluent of similar estrogenic potencies. Less information is available about the more numerous biological (trickling) filter plants (BFP) in the UK and oxygen ditches (OD) in Japan which tend to serve smaller, more rural communities. The available data would suggest that the BFPs are significantly less efficient than the ODs at removing E1. This would suggest that in similar circumstances, British headwaters (where this sewage treatment plant (STP) type is often found) might be more at risk from endocrine disruption than their Japanese counterparts. Overall, the apparently higher incidence of endocrine disruption in British wild fish than in Japanese wild fish cannot be attributed to differences in the efficiency of their respective STPs.     

Zoogeographical aspects of rocky-intertidal molluscan fauna of the Pacific coasts of Japan

Intertidal molluscan faunas were studied on the exposed rocky shores of the Pacific coasts of Japan (excluding Hokkaido) to determine distribution patterns and latitudinal gradients of taxa. Collections were made at spring low tide in 1980. Five types of distribution patterns were found: tropical, tropical-temperate, warm-temperate, temperate, and boreal. Many examples of parallel species displacement, the term which Thorson (1957) proposed and generalized, were found. Latitudinal gradients of molluscan taxon were observed. Frequency of the Archaeogastropoda in gastropods increases northward, while frequency of the Mesogastropoda and the Neogastropoda decreases. Frequency of predatory gastropods decreases northward, and that of herbivorous ones increases. Commonness indices show that the molluscan fauna of the study sites situated within the wide area between the Kanto and Kyushu are closely related with each other, and they can be regarded as one province. The Tohoku district is less related with this region, and the Okinawa district is the least related.     

Relationship between the growth and survival of larval Pacific bluefin tuna, Thunnus orientalis

We tested the hypothesis that a large body size and rapid growth rate affect the survival of larval Pacific bluefin tuna, Thunnus orientalis (PBT), and analyzed larval growth in relation to environmental conditions. Seven high density larval patches of PBT were tracked with reference buoys in the northwestern Pacific Ocean for 28–171 h in May–June from 2004 to 2008. The otolith radii and daily growth rates of the survivor larvae (collected on later tracking days of each tracking session) tended to be larger and more rapid, respectively, than those of original larvae (collected on earlier tracking days). A large body size was found to positively affect the survival of larval PBT, as did a rapid growth rate, even at an early larval stage (7 days after hatching). Generalized linear modeling showed that the otolith radius was influenced positively by the sea temperature, stratification parameter and food density, while the growth rate was influenced positively by the sea temperature and food density.     

Cadmium,copper, and zinc in carrots in Japan

Cadmium (Cd), copper (Cu), and zinc (Zn) in carrots obtained from different regions throughout Japan were assessed in a baseline study on the contents of trace metals in foods. These three metals were measured by flameless atomic absorption spectrophotometry. The geometric mean contents (with one geometric standard deviation indicated in parentheses) of Cd, Cu, and Zn were 0.02 (2.2), 0.7 (2.1), and 2.4 (1.6) mg?kg^?1 wet weight in carrots obtained in Japan. While there was a close relationship among the contents of the three metals in the carrots grown in Cambisols and Gleysols, a significant relationship was recognized only between the contents of Cd and Zn in those grown in Andosols and Fluvic Gleysols. Cd and Zn are classified as 2B metals in the periodic table of elements, and the authors speculate that the similarity of the metal characteristics between Cd and Zn may be responsible for the close relationship in the contents of the two metals, with no relation to the soil type.     

Active Biodegradable Cassava Starch Films Containing Sophorolipids Produced by Starmerella bombicola ATCC® 22214™

Journal of Polymers and the Environment - Sophorolipids are glycolipid biosurfactants produced by the yeast Starmerella bombicola. They have great potential for application in the food industry due...