Changes in the rate of synthesis of wall polysaccharides during the cell cycle of yeast

Reevaluation and comparison of seemingly contradictory literature data on the mode of synthesis of wall polysaccharides during the cell cycle ofSaccharomyces cerevisiae explained the source of discrepancies and demonstrated their general consonance in the following points: 1. The rate of synthesis of glucan and mannan is not constant and does not increase continuously throughout the entire cell cycle. 2. The rate of synthesis of both polysaccharides is considerably reduced at the time of cell division and in the prebudding phase.     

Cell wall glycoproteins from Chlamydomonas reinhardii are sulphated

Abstract Both the two major structural cell wall glycoproteins and the soluble excreted glycoproteins of Chlamydomonas reinhardii Levine WT II/32 contain low levels (approx. 1–4%) of sugar O-sulphate esters, asymmetrically distributed within the molecules. Preliminary characterization of their structure is described through [³⁵S] sulphate labelling experiments. The function of the sulphated glycoproteins is discussed in terms of their structural role and their water retaining properties.     

Tissue Mechanics Regulate Mitotic Nuclear Dynamics during Epithelial Development

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Atmospheric and room temperature plasma mutagenesis and astaxanthin production from sugarcane bagasse hydrolysate by Phaffia rhodozyma mutant Y1

In this study, atmospheric and room temperature plasma and ultraviolet mutagenesis was studied for astaxanthin overproducing mutant. Phaffia rhodozyma mutant Y1 was obtained from the selection plate with 120 μmol/L diphenylamine as selection agent, and its carotenoid concentration and content were 54.38 mg/L and 5.38 mg/g, which were 19.02 % and 21.20 % higher than that of the original strain, respectively. Sugarcane bagasse hydrolysate was used for astaxanthin production by mutant Y1 at 22 °C and 220 rpm for 96 h, and the biomass and carotenoid concentration reached 12.65 g/L and 88.57 mg/L, respectively. Ultrasonication and cellulase were used to break cell wall and the parameters were optimized, achieving an astaxanthin extraction rate of 96.01 %. The present work provided a novel combined mutagenesis method for astaxanthin overproducing mutant and a green cell wall disruption process for astaxanthin extraction, which would play a solid foundation on the development of natural astaxanthin.     

Using anticipatory life cycle assessment to enable future sustainable construction

The built environment is the largest single emitter of CO₂ and an important consumer of energy. Much research has gone into the improved efficiency of building operation and construction products. Life Cycle Assessment (LCA) is commonly used to assess existing buildings or building products. Classic LCA, however, is not suited for evaluating the environmental performance of developing technologies. A new approach, anticipatory LCA (a‐LCA), promises various advantages and can be used as a design constraint during the product development stage. It helps overcome four challenges: (i) data availability, (ii) stakeholder inclusion, (iii) risk assessment, and (iv) multi‐criteria problems. This article's contribution to the line of research is twofold: first, it adapts the a‐LCA approach for construction‐specific purposes in theoretical terms for the four challenges. Second, it applies the method to an innovative prefabricated modular envelope system, the CleanTechBlock (CTB), focusing on challenge (i). Thirty‐six CTB designs are tested and compared to conventional walls. Inclusion of technology foresight is achieved through structured scenario analysis. Moreover, challenge (iv) is tackled through the analysis of different environmental impact categories, transport‐related impacts, and thickness of the wall assemblies of the CTB. The case study results show that optimized material choice and product design is needed to reach the lowest environmental impact. Methodological findings highlight the importance of context‐specific solutions and the need for benchmarking new products.     

Factors Affecting the Mixotrophic Flagellate Poterioochromonas malhamensis Grazing on Chlorella Cells

Grazing behaviour between protozoa and phytoplankton exists widely in planktonic ecosystems. Poterioochromonas malhamensis is a well‐known and widespread mixotrophic flagellate, which is recognized to play an important role within marine and freshwater planktonic ecosystems and regarded as the greatest contamination threat for mass algal cultures of Chlorella. In this study, a comprehensive range of factors, including morphological characters, biochemical compositions, and specific growth rate of ten species or strains of Chlorella, were evaluated for their effect on the feeding ability of P. malhamensis, which was assessed by two parameters: the clearance rate of P. malhamensis on Chlorella spp. and the specific growth rate of P. malhamensis. The results showed that the clearance rate of P. malhamensis was negatively correlated with cell wall thickness and specific growth rate of Chlorella spp., while the specific growth rate of P. malhamensis was positively correlated with carbohydrate percentage and C/N ratio and negatively correlated with protein, lipid percentage, and nitrogen mass. In conclusion, the factors influencing feeding selectivity include not only the morphological character and chemical composition of Chlorella, but also its population dynamics. Our study provides useful insights into the key factors that affect the feeding selectivity of P. malhamensis and provides basic and constructive data to help in screening for grazing‐resistant microalgae.     

New clade of silicified bolidophytes that belong to Triparma (Bolidophyceae,Stramenopiles)

The small phytoplankton genus Triparma belongs to the class Bolidophyceae and contains two distinct forms: silicified species and naked flagellated species (formerly Bolidomonas). Recent studies showed that four silicified species/strains (Triparma laevis f. inornata, T. laevis f. longispina, T. strigata, and T. aff. verrucosa) belong to a single clade that is paraphyletic, because it also contains an unclassified flagellated strain, and is sister to a flagellated species, T. eleuthera. In this study, we isolated and characterized two new strains of silicified species to test the phylogenetic unity of silicified bolidophytes. The isolates were identified as T. retinervis strains because they possessed fine areolation on the cell wall. 18S rDNA and rbcL phylogenetic analyses demonstrated that T. retinervis formed a new silicified clade that is sister to the flagellated species T. pacifica. This reveals that there are at least two distinct clades including both silicified and flagellated Triparma species.