Journal of Applied Phycology最新文献

Fucoidan is a fucose-rich sulfated polysaccharide found mainly in brown seaweeds. Fucoidan has recently gained much attention due to its bioactive and medicinal properties, hence its high potential to be utilized in the pharmaceutical industry. Therefore, an accurate, reliable, and simple method for the specific determination of fucoidan would be a useful tool when looking to recover this valuable polysaccharide. This research focused on developing an assay utilizing the thiazine dye, methylene blue, for the quantification of fucoidan, with a specific application for fucoidan found in algal extracts. Fucoidan could be specifically determined at pH 1, to maximum concentrations of 4 g L^-1 in solution without the interference of alginate and other seaweed extract contaminants. At pH 7 and 11, quantification of fucoidan led to interference from alginate and gallic acid. A conversion factor of 1.8 allowed the quantification of fucoidan from Ecklonia maxima extracts using a commercial standard from Fucus vesiculosis. An Ecklonia maxima extract was found to contain 5.47 ± 0.061 g L^-1 of fucoidan. Measuring the fucoidan and L-fucose concentration in crude seaweed extract through the methylene blue assay and modified Dische and Shettles J Biol Chem 175:595–603, (1948) method, respectively, confirmed the accuracy and specificity of the method. The limit of quantification of the methylene blue assay at pH 1 was 0.62 g L^-1 of fucoidan.

Although established biotechnological applications of microalgae e.g., the production of high-value metabolites is based on axenic cultures, exploitation of the mutualistic consortia of microalgae and bacteria quickly comes to foreground, especially in bioremediation and wastewater treatment. This trend shifts the focus from genomic research of certain microalgal species to metagenomic studies of interactions between microalgae and bacteria in natural communities and in artificial consortia. Dissection of the genetic determinants of the robustness and productivity of the consortia become a hot research direction, too. Admirable contribution to this topic had been made by high-throughput sequencing (HTS), while recent breakthrough in this field was entailed by the advent and rapid development of the 3rd generation nanopore sequencing which becomes increasingly accurate while providing unprecedented sequencing performance. Recent progress of the Oxford Nanopore Technologies (ONT) enabled both classical metagenomic analysis of microalgal-bacterial communities based on whole metagenome sequencing as well as taxonomic and genetic profiling based on the amplicon sequencing. The parallel emergence of novel bioinformatic algorithms for processing the metagenomic datasets opened new opportunities for the analysis of structure and physiology of microalgal-bacterial communities. From the practical perspective, the new HTS techniques became a time- and labor-savers in discovery of new microalgae with a high potential for the accumulation of valuable metabolites, biodegradation of hazardous micropollutants, and biosequestration of nutrients from waste streams. Search for prokaryotic species boosting the biotechnological potential of eukaryotic microalgae via mutualistic interactions with them is another important goal. The insights from the both short-read and long-read metagenomics will form a solid foundation for the rational design of microalgal-bacterial consortia for biotechnology. In this review, we briefly outline the benefits of the long-read sequencing for structural and functional investigation of algal-bacterial consortia and summarize recent reports on using this approach for achieving the biotechnology-related goals.