Pyrolytic and Kinetic Analysis of Two Coastal Plant Species: Artemisia annua and Chenopodium glaucum

The large amount of coastal plant species available makes them ideal candidates for energy production. In this study, thermogravimetric analysis was used to evaluate the fuel properties of two coastal plant species, and the distributed activation energy model (DAEM) was employed in kinetic analysis. The major mass loss due to devolatilization started at 154 and 162 degrees C at the heating rate of 10 degrees C min(-1) for Artemisia annua and Chenopodium glaucum, respectively. The results showed that the average activation energies of Artemisia annua and Chenopodium glaucum were 169.69 and 170.48 kJ mol(-1), respectively. Furthermore, the activation energy changed while the conversion rate increased, and the frequency factor k(0) decreased greatly while the activation energy decreased. The results also indicated that the devolatilization of the two coastal plant species underwent a set of first-order reactions and could be expressed by the DAEM. Additionally, a simplified mathematical model was proposed to facilitate the prediction of devolatilization curves.The large amount of coastal plant species available makes them ideal candidates for energy production. In this study, thermogravimetric analysis was used to evaluate the fuel properties of two coastal plant species, and the distributed activation energy model (DAEM) was employed in kinetic analysis. The major mass loss due to devolatilization started at 154 and 162 degrees C at the heating rate of 10 degrees C min(-1) for Artemisia annua and Chenopodium glaucum, respectively. The results showed that the average activation energies of Artemisia annua and Chenopodium glaucum were 169.69 and 170.48 kJ mol(-1), respectively. Furthermore, the activation energy changed while the conversion rate increased, and the frequency factor k(0) decreased greatly while the activation energy decreased. The results also indicated that the devolatilization of the two coastal plant species underwent a set of first-order reactions and could be expressed by the DAEM. Additionally, a simplified mathematical model was proposed to facilitate the prediction of devolatilization curves

Transcriptomic analysis of Synechocystis sp PCC6803 under low-temperature stress

In this study, cDNA microarrays were developed from 3569 mRNA reads to analyze the expression profiles of the transcriptomes of Synechocystis sp. PCC6803 under low temperature (LT) stress. Among the genes on the cDNA microarrays, 899 LT-affected genes exhibited a 1.5-fold (or greater) difference in expression compared with the genes from normal unstressed Synechocystis sp. PCC6803. Of the differentially expressed genes, 353 were up-regulated and 246 were down-regulated. The results showed that genes involved in photosynthesis were activated at LT (10A degrees C), including genes for photosystem I, photosystem II, photosynthetic electron transport, and cytochrome b6/f complex. Moreover, desB, one of four genes that encode the fatty acid desaturases, was also induced by LT. However, the LT conditions to some degree enhanced the transcription of some genes. In addition, LT (10A degrees C) may reduce cellular motility by regulating the transcription of spkA (sll1575), a serine/threonine protein kinase. The results reported in this study may contribute to a better understanding of the responses of the Synechocystis cell to LT, including pathways involved in photosynthesis and repair.In this study, cDNA microarrays were developed from 3569 mRNA reads to analyze the expression profiles of the transcriptomes of Synechocystis sp. PCC6803 under low temperature (LT) stress. Among the genes on the cDNA microarrays, 899 LT-affected genes exhibited a 1.5-fold (or greater) difference in expression compared with the genes from normal unstressed Synechocystis sp. PCC6803. Of the differentially expressed genes, 353 were up-regulated and 246 were down-regulated. The results showed that genes involved in photosynthesis were activated at LT (10A degrees C), including genes for photosystem I, photosystem II, photosynthetic electron transport, and cytochrome b6/f complex. Moreover, desB, one of four genes that encode the fatty acid desaturases, was also induced by LT. However, the LT conditions to some degree enhanced the transcription of some genes. In addition, LT (10A degrees C) may reduce cellular motility by regulating the transcription of spkA (sll1575), a serine/threonine protein kinase. The results reported in this study may contribute to a better understanding of the responses of the Synechocystis cell to LT, including pathways involved in photosynthesis and repair

Gene cloning and expression profile of a novel carotenoid hydroxylase (CYP97C) from the green alga Haematococcus pluvialis

A full-length complementary DNA (cDNA) sequence of epsilon-ring CHY (designated Haecyp97c) was cloned from the green alga Haematococcus pluvialis by reverse transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends methods. The Haecyp97c cDNA sequence was 1,995 base pairs (bp) in length, which contained a 1,620-bp open reading frame, a 46-bp 5'-untranslated region (UTR), and a 329-bp 3'-UTR with the characteristic of the poly (A) tail. The deduced protein had a calculated molecular mass of 58.71 kDa with an estimated isoelectric point of 7.94. Multiple alignment analysis revealed that the deduced amino acid sequence of HaeCYP97C shared high identity of 72-85 % with corresponding CYP97Cs from other eukaryotes. The catalytic motifs of cytochrome P450s were detected in the amino acid sequence of HaeCYP97C. The transcriptional levels of Haecyp97c and xanthophylls accumulation under high light (HL) stress have been examined. The results revealed that Haecyp97c transcript was strongly increased after 13-28 h under HL stress. Meanwhile, the concentrations of chlorophylls, carotenes, and lutein were decreased, and zeaxanthin and astaxanthin concentrations were increased rapidly, respectively. These facts indicated that HaeCYP97C was perhaps involved in xanthophyll biosynthesis, which plays an important role in adaption to HL for H. pluvialis.A full-length complementary DNA (cDNA) sequence of epsilon-ring CHY (designated Haecyp97c) was cloned from the green alga Haematococcus pluvialis by reverse transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends methods. The Haecyp97c cDNA sequence was 1,995 base pairs (bp) in length, which contained a 1,620-bp open reading frame, a 46-bp 5'-untranslated region (UTR), and a 329-bp 3'-UTR with the characteristic of the poly (A) tail. The deduced protein had a calculated molecular mass of 58.71 kDa with an estimated isoelectric point of 7.94. Multiple alignment analysis revealed that the deduced amino acid sequence of HaeCYP97C shared high identity of 72-85 % with corresponding CYP97Cs from other eukaryotes. The catalytic motifs of cytochrome P450s were detected in the amino acid sequence of HaeCYP97C. The transcriptional levels of Haecyp97c and xanthophylls accumulation under high light (HL) stress have been examined. The results revealed that Haecyp97c transcript was strongly increased after 13-28 h under HL stress. Meanwhile, the concentrations of chlorophylls, carotenes, and lutein were decreased, and zeaxanthin and astaxanthin concentrations were increased rapidly, respectively. These facts indicated that HaeCYP97C was perhaps involved in xanthophyll biosynthesis, which plays an important role in adaption to HL for H. pluvialis

Microalgal industry in China: challenges and prospects

Over the past 15 years, China has become the major producer of microalgal biomass in the world. Spirulina (Arthrospira) is the largest microalgal product by tonnage and value, followed by Chlorella, Dunaliella, and Haematococcus, the four main microalgae grown commercially. China's production is estimated at about two-thirds of global microalgae biomass of which roughly 90 % is sold for human consumption as human nutritional products ('nutraceuticals'), with smaller markets in animal feeds mainly for marine aquaculture. Research is also ongoing in China, as in the rest of the world, for other high-value as well as commodity microalgal products, from pharmaceuticals to biofuels and CO2 capture and utilization. This paper briefly reviews the main challenges and potential solutions for expanding commercial microalgae production in China and the markets for microalgae products. The Chinese Microalgae Industry Alliance (CMIA), a network founded by Chinese microalgae researchers and commercial enterprises, supports this industry by promoting improved safety and quality standards, and advancement of technologies that can innovate and increase the markets for microalgal products. Microalgae are a growing source of human nutritional products and could become a future source of sustainable commodities, from foods and feeds, to, possibly, fuels and fertilizers

Coastal biodiversity and bioresources: variation and sustainability

The 1(st) International Coastal Biology Congress (1(st) ICBC) was held in Yantai, China, in Sep. 26-30, 2014. Eighteen manuscripts of the meeting presentations were selected in this special issue. According to the four themes set in the ICBC meeting, this special issue include four sections, i.e., Coastal Biodiversity under Global Change, Adaptation and Evolution to Special Environment of Coastal Zone, Sustainable Utilization of Coastal Bioresources, and Coastal Biotechnology. Recent advances in these filed are presented

Evolution of eukaryotic algae: a mini-review of progress and problems

研究藻类的进化历史对理解生命起源与进化有着承前启后的重要意义,然而多年来国内许多资料中仍然沿用陈旧的藻类进化理论和观点,带有时代局限性的色素决定论"三条进化路线"的观点用于描述藻类进化路径不尽准确,而"光质-色素"进化适应理论的推测用于解释藻类进化原理并不合理。综述了国外藻类进化研究中对"光质-色素"进化适应理论的批判,以及目前国际最有影响力的关于藻类进化的囊泡藻假说的相关研究进展。最后基于藻类进化的公认进展对国内外藻类分类方法作了比较,指出国内落后于国际前沿的若干问题所在,希望为解开藻类进化工作者入门时因为这些问题而常常遇到的困惑提供一些关键前沿理论参考

Enhanced green fluorescent protein (egfp) gene expression in Tetraselmis subcordiformis chloroplast with endogenous regulators

On the basis of fundamental genetic transformation technologies, the goal of this study was to optimize Tetraselmis subcordiformis chloroplast transformation through the use of endogenous regulators. The genes rrn16S, rbcL, psbA, and psbC are commonly highly expressed in chloroplasts, and the regulators of these genes are often used in chloroplast transformation. For lack of a known chloroplast genome sequence, the genome-walking method was used here to obtain full sequences of T. subcordiformis endogenous regulators. The resulting regulators, including three promoters, two terminators, and a ribosome combination sequence, were inserted into the previously constructed plasmid pPSC-R, with the egfp gene included as a reporter gene, and five chloroplast expression vectors prepared. These vectors were successfully transformed into T. subcordiformis by particle bombardment and the efficiency of each vector tested by assessing EGFP fluorescence via microscopy. The results showed that these vectors exhibited higher efficiency than the former vector pPSC-G carrying exogenous regulators, and the vector pRFA with Prrn, psbA-5'RE, and TpsbA showed the highest efficiency. This research provides a set of effective endogenous regulators for T. subcordiformis and will facilitate future fundamental studies of this alga

Impacts of Mariculture on the Diversity of Bacterial Communities within Intertidal Sediments in the Northeast of China

Mariculture is one of the major seafood supplies worldwide and has caused serious environmental concerns on the coastal zone. Its rapid development has been shown to disrupt the sediment ecosystems and thus influence the benthic bacterial communities. Bacterial diversity and community structure within both adjacent farms and non-cultured zones intertidal sediments along the coasts of Qinhuangdao and Dalian, China, were investigated using full-length 16S rRNA gene-based T-RFLP analyses and clone library construction. Richness and Shannon-Wiener index were significantly increased at sites adjacent the mariculture farm with mean values of 29 and 2.97 from peak profiles of T-RFLP result. Clustering analyses suggested that impacts of mariculture on bacterial diversity of sediment were significantly larger than those resulted from temporal and spatial scales. Upon comparisons of RFLP patterns from 602 clones from libraries of the selected five samples, 137 OTUs were retrieved. Members of gamma- and delta-Proteobacteria, Bacilli, Flavobacteria, and Actinobacteria were recorded in all libraries. In addition, gamma-Proteobacteria were dominant in all samples (21.7 similar to 45.0 %). Redundancy analysis revealed that the distribution of bacterial composition seemed to be determined by the variables of salinity, PO4 (3-)-P, NH4 (+)-N, and Chlorophyll a content. The phyla of gamma-Proteobacteria, Clostridia, Flavobacteria, Bacilli, and Planctomycetes were principal components to contribute to the bacterial differences of clone libraries. Our finding demonstrated that these phyla could display variations of bacterial composition linked to environmental disturbance resulted from mariculture

Chloroplast Transformation of Platymonas (Tetraselmis) subcordiformis with the bar Gene as Selectable Marker

The objective of this research was to establish a chloroplast transformation technique for Platymonas (Tetraselmis) subcordiformis. Employing the gfp gene as a reporter and the bar gene as a selectable marker, transformation vectors of P. subcordiformis chloroplast were constructed with endogenous fragments rrn16S-trnl (left) and trnA-rrn23S (right) as a recombination site of the chloroplast genome. The plasmids were transferred into P. subcordiformis via particle bombardment. Confocal laser scanning microscopy indicated that the green fluorescence protein was localized in the chloroplast of P. subcordiformis, confirming the activity of the Chlamydomonas reinhardtii promoter. Cells transformed with the bar gene were selected using the herbicide Basta. Resistant colonies were analyzed by PCR and Southern blotting, and the results indicated that the bar gene was successfully integrated into the chloroplast genome via homologous recombination. The technique will improve genetic engineering of this alga