Search

Abstract: The economic feasibility of algal mass culture for biodiesel production is enhanced by the increase in biomass productivity and storage lipids. Effect of iron on growth and lipid accumulation in marine microalgae Chlorella vulgaris were investigated. In experiment I, supplementing the growth media with chelated FeCl3 in the late growth phase increased the final cell density but did not induce lipid accumulation in cells. In experiment II, cells in the late-exponential growth phase were collected by centrifugation and re-inoculated into new media supplemented with five levels of Fe3+ concentration. Total lipid content in cultures supplemented with 1.2×10−5 molL−1 FeCl3 was up to 56.6% biomass by dry weight and was 3–7-fold that in other media supplemented with lower iron concentration. Moreover, a simple and rapid method determining the lipid accumulation in C. vulgaris with spectrofluorimetry was developed. [Copyright &y& Elsevier]

B-phycoerythrin (BPE) and R-phycocyanin (RPC) were purified from Porphyridium cruentum by Sephadex G-200 chromatography, then the BPE was attached covalently to the RPC by reacting their amino groups to form the artificially covalent BPE–RPC conjugate in which the excitation energy can transfer from the BPE to the RPC with low efficiency. Meanwhile, the intact phycobilisome (PBS) consisting of BPE, RPC, APC and LCM was isolated and purified from Porphyridium cruentum, and the purified PBS was found to keep intact if the solution contains sucrose. Comparison of spectroscopic properties between the purified PBS and the BPE–RPC conjugate suggests that the BPE–RPC conjugate is much more stable than the purified PBS. The construction of BPE–RPC conjugate with low efficiency of the excitation energy transfer may be useful for preparing phycobiliprotein probes. [Copyright &y& Elsevier]

Objective: To compare the effects of intraepididymal quercetin (IE-QE) with those of intraperitoneal quercetin (IP-QE) on testicular torsion/detorsion (TD)-induced ischemia/reperfusion (IR) injury of the testes in an experimental rat model.Methods: Twenty-four rats were divided into 4 groups: sham (S), TD, TD treated with IP-QE, and TD treated with IE-QE. The IP-QE group received 20 mg/kg QE intraperitoneally, whereas the IE-QE group received quercetin (QE) epididymally. After surgically induced TD, sera and testicular tissues were obtained for the analysis of biochemical parameters including glutathione peroxidase (GPx), malondialdehyde, total antioxidant status, total oxidant status, oxidative stress index, histologic changes, and evaluation of germ cell apoptosis.Results: The oxidative stress index and oxidants (malondialdehyde and total oxidant status) were increased with a concomitant decrease in the antioxidants (GPx and total antioxidant status) in the TD group. Severe histopathological damage, indicated by low Johnsen scores and high testicular injury grades, and germ cell apoptosis were found in the TD group compared with the other groups. Rats treated with QE showed significantly less IR injury, with moderately altered biochemical parameters, histopathological damage, and germinal cell apoptosis compared with the TD group. Most importantly, we found no significant differences in the biochemical parameters, histopathological changes, and germinal cell apoptosis between the IP-QE and IE-QE groups.Conclusion: IE-QE was comparable to IP-QE in the treatment of testicular TD. Local QE therapy should be considered as a new approach to treating testicular IR injury due to TD. [ABSTRACT FROM AUTHOR]

Highlights: [•] Taxonomic probes of six harmful algae were designed and their specificity was confirmed by dot blot hybridization. [•] The established multiple PCR coupled with reverse dot blot hybridization (MPCRDBH) demonstrated a detection limit of 0.6 cell. [•] MPCRDBH could recover all target species and was not affected by background DNA. [•] MPCRDBH also demonstrated a stable detection performance for fixative (acidic Lugol's solution)-preserved samples over 30d. [•] MPCRDBH applicability was assessed and proven effective for parallel detection of target microalgae in the field samples. [ABSTRACT FROM AUTHOR]

Abstract: Gracilaria lemaneiformis (Bory) Daws has been extensively cultivated as a source of commercial agar and the ecomaterials in Shenao Bay, Guangdong Province, Jiaozhou Bay, Shandong Province and other waters in China. This paper examines the in situ suspended farming of G. lemaneiformis using raft cultivation under different conditions and its effects on nutrient removal in the laboratory. The results showed that cultivated Gracilaria grew well in both Shenao Bay and Jiaozhou Bay. The biomass of Gracilaria increased from 50 to 775 g m−1 (fresh weight) during 28 days, with special growth rate (SPG) 13.9% d−1 under horizontal cultivation in Jiaozhou Bay. Light, temperature, nutrient supply, as well as cultivation treatments such as initial density, and depth of suspension seaweed were important to the growth of Gracilaria. The highest biomass production was observed in the horizontal culture condition (0.0 m) and 0.5–1.5 m deep layer in Jiaozhou Bay. However, the highest growth rate in Shenao Bay appeared under the lowest initial stocking density treatment. In the laboratory, the aquarium experiments (fish and seaweed culture systems) demonstrated that Gracilaria was able to remove inorganic nutrients effectively. The concentration of NH4 +–N decreased by 85.53% and 69.45%, and the concentration of PO4–P decreased 65.97% and 26.74% in aquaria with Gracilaria after 23 days and 40 days, respectively. The results indicate that Gracilaria has the potential to remove excess nutrient from coastal areas, and the large-scale cultivation of G. lemaneiformis could be effective to control eutrophication in Chinese coastal waters. [Copyright &y& Elsevier]