[Reconstructing habitat history of Larimichthys polyactis in Lüsi coastal waters of Jiangsu Province, China based on otolith microchemistry].

An electron probe microanalyzer (EPMA) was applied to analyze the element Sr and Ca microchemistry patterns in otoliths of Larimichthys polyactis in Lüsi coastal waters of Jiangsu Province, China. The results showed that Sr was heterogeneously distributed along the sagittal plane of the otoliths. The highest Sr concentration was normally found in the otolith cores while much lower concentrations were found in the remaining areas. The corresponding Sr/Ca ratios were (7.10 +/- 1.00) and (4.79 +/- 1.01) in the former and latter, respectively, which were significantly differed (P < 0.01), but low Sr/Ca ratios even as low as (3.51 +/- 0.76) were also observed in several fish. Based on the above results of otolith microchemistry, the habitat history of L. polyactis was reconstructed as that high salinity habitats seemed to be required at the stages of hatching and post-hatching development, while the reduced salinity habitats seemed to be preferable for the growth and development at the remaining stages of the life history. Furthermore, several fish in this study had likely even experienced much lower salinity habitats at the early stages.

Integrated biocatalytic process for trehalose production and separation from rice hydrolysate using a bioreactor system.

Rice starch can be hydrolyzed into maltose for trehalose bioconversion by enzymatic methods. In this study, we have successfully established an efficient production system for our recombinant PTTS in large scale. Three bio-treatments were developed to simplify the separation and purification of trehalose from complex rice saccharified liquid. The trehalose conversion rate of 64.63±4.05% at 30 °C can be reached using rice hydrolysate as the substrate in a 5l fermentor system. By 1% of raw material koji fermentation, the highest concentration of bioethanol (3.61±0.07%) was obtained at 30 °C for 36 h. After 12h of reaction time, the gluconic acid (24.47±0.33 mM) was successfully produced by glucose oxidase (40 U/g rice) using residual glucose as a substrate. After the batch/continuous ionic exchange process, the trehalose can be successfully separated, crystallized and identified as 92.6±0.02% purity and 94.2% of the recovery yield, respectively.