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Iron is an essential element for nearly all cells and limited iron availability often restricts growth. However, excess iron can also be deleterious, particularly when cells expressing high affinity iron uptake systems transition to iron rich environments. B acillus subtilis expresses numerous iron importers, but iron efflux has not been reported. Here, we describe the B. subtilis PfeT protein (formerly YkvW/ ZosA) as a P1B4-type ATPase in the PerR regulon that serves as an Fe( II) efflux pump and protects cells against iron intoxication. Iron and manganese homeostasis in B. subtilis are closely intertwined: a pfe T mutant is iron sensitive, and this sensitivity can be suppressed by low levels of Mn( II). Conversely, a pfe T mutant is more resistant to Mn( II) overload. In vitro, the PfeT ATPase is activated by both Fe( II) and Co( II), although only Fe( II) efflux is physiologically relevant in wild-type cells, and null mutants accumulate elevated levels of intracellular iron. Genetic studies indicate that PfeT together with the ferric uptake repressor (Fur) cooperate to prevent iron intoxication, with iron sequestration by the MrgA mini-ferritin playing a secondary role. Protection against iron toxicity may also be a key role for related P1B4-type ATPases previously implicated in bacterial pathogenesis. [ABSTRACT FROM AUTHOR]

Improving the drought resistance of rice is of great significance for expanding the planting area and improving the stable yield of rice. In our previous work, we found that ROLLED AND ERECT LEAF1 (REL1) protein promoted enhanced tolerance to drought stress by eliminating reactive oxygen species (ROS) levels and triggering the abscisic acid (ABA) response. However, the mechanism through which REL1 regulates drought tolerance by removing ROS is unclear. In this study, we identified REL1 interacting protein 5 (RIP5) and found that it directly combines with REL1 in the chloroplast. We found that RIP5 was strongly expressed in ZH11 under drought-stress conditions, and that the rip5-ko mutants significantly improved the tolerance of rice plants to drought, whereas overexpression of RIP5 resulted in greater susceptibility to drought. Further investigation suggested that RIP5 negatively regulated drought tolerance in rice by decreasing the content of ascorbic acid (AsA), thereby reducing ROS clearance. RNA sequencing showed that the knockout of RIP5 caused differential gene expression that is chiefly associated with ascorbate and aldarate metabolism. Furthermore, multiple experimental results suggest that REL1 is involved in regulating drought tolerance by inhibiting RIP5. Collectively, our findings reveal the importance of the inhibition of RIP5 by REL1 in affecting the rice's response to drought stress. This work not only explains the drought tolerance mechanism of rice, but will also help to improve the drought tolerance of rice. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the multiple attribute decision making problems with dual hesitant fuzzy information, in which the information about attribute weights is incompletely known, and the attribute values take the form of dual hesitant fuzzy values. We first introduce some approaches to obtaining the weight information of attributes, and then establish an optimization model based on the positive ideal point of attribute values, by which the attribute weights can be determined. For the special situations where the information about attribute weights is completely unknown, we establish another optimization model. By solving this model, we get a simple and exact formula, which can be used to determine the attribute weights. We compute the correlation coefficient between each alternative and positive ideal alternative, and then rank the alternatives by means of the correlation coefficient between each alternative and positive ideal alternative. Finally, we shall present a numerical example to show the pattern recognition problems about the classification of metal materials with dual hesitant fuzzy information in order to illustrate the method proposed in this paper. [ABSTRACT FROM AUTHOR]

Abstract: An extremely thermostable xylanaseB gene from hyperthermophilic bacterium Thermotoga maritima was ligated to pGHE vector and expressed in filamentous fungus Aspergillus niger. The vector was constructed using endogenous strong gla promoter, signal sequence, and pro-sequence (NVISKR). Positive transformants of the expression vector secreted XynB with thermostable characteristics, and optimal temperature >90°C. Yield of XynB in shaking culture reached ∼0.5g/l. Maximal enzymatic activity occurred at day 6, and was recorded as 625U/ml fermentation supernatant in a transformant using Remazol Brilliant Blue R-D-Xylan as substrate. mRNA levels of gla, bip, and hac1 between recombinant and control strain were detected by quantitative reverse transcription PCR. None of these three genes was regulated in the strain of xynB integration, indicating that high expression of XynB did not induce unfolded protein response. [Copyright &y& Elsevier]

Highlights: [•] A novel mono-and diacylglycerol lipase (MDL) gene was highly expressed in Pichia pastoris and named as Lipase GH1. [•] Lipase GH1 is a glycosylated protein and stable under alkaline conditions. [•] Lipase GH1 exhibited the potential application for preparation food emulsifiers. [Copyright &y& Elsevier]

In this work, the medium containing ionic products of dicalcium silicates (Ca2SiO4) for culturing MG63 cells was prepared by immersing a titanium alloy plate with the plasma sprayed Ca2SiO4 coatings in DMEM solution. The effect of the ionic products on cellular differentiation, collagen production, and local growth factors (prostaglandin E2 [PGE2] and transforming growth factor-β [TGF-β1]) of osteoblast-like MG63 cells were investigated. The normal DMEM was also used to culture MG63 cells as the control group. Differentiation of cell was evaluated by detecting alkaline phosphatase (ALP) activity and osteocalcin (OC) synthesis as well as their gene expression. Collagen production was analyzed by Sircol assay. The levels of PGE2 and TGF-β1 in culture medium were measured using enzyme-linked immunosorbent assay (ELISA). The gene expressions of TGF-β receptors (TGF-β RI and TGF-β RII) were also measured by real-time PCR technology. MG63 cells cultured in DMEM containing ionic products of Ca2SiO4 coating showed enhanced differentiation and increased collagen production. The results obtained from ELISA showed that the levels of PGE2 and TGF-β1 in experimental group were higher than that in control. The gene expression of TGF-β receptors was upregulated, indicating that more TGF-β1 bonded to their receptors which produce more effects on the osteoblastic activity, leading to enhanced differentiation and synthetic activity of osteoblast. It is concluded that ionic products of Ca2SiO4 coating may enhance cellular differentiation and collagen production by influencing TGF-β1 pathway. [ABSTRACT FROM AUTHOR]

An astaxanthin-overproducing (∼1000 μg g) strain of Phaffia rhodozyma, termed MK19, was established through 1-methyl-3-nitro-1-nitrosoguanidine and Co60 mutagenesis from wild-type JCM9042 (merely 35-67 μg g). The total fatty acid content of MK19 was much lower than that of the wild type. Possible causes of the astaxanthin increase were studied at the gene expression level. The expression of the carotenogenic genes crtE, crtI, pbs, and ast, which are responsible for astaxanthin biosynthesis from geranylgeranyl pyrophosphate, was highly induced at the mRNA level, leading to excessive astaxanthin accumulation. In contrast, transcription levels of the genes ( hmgs, hmgr, idi, mvk, mpd, fps), responsible for the initial steps in the terpenoid pathway, were essentially the same in wild type and MK19. Although fatty acid and total ergosterol content were reduced by 40-70 mg g and 760.3 μg g, respectively, in MK19 as compared with the wild type, but the transcription levels of rate-limiting genes in fatty acid and ergosterol pathways such as acc and sqs were similar. Because fatty acids and ergosterol are two branch pathways of astaxanthin biosynthesis in P. rhodozyma, our findings indicate that enhancement of astaxanthin in MK19 results from decreased fatty acid and ergosterol biosynthesis, leading to precursor accumulation, and transfer to the astaxanthin pathway. Strengthening of the mevalonate pathway is suggested as a promising metabolic engineering approach for further astaxanthin enhancement in MK19. [ABSTRACT FROM AUTHOR]

Abstract: A combination of two lipases was employed to catalyze methanolysis of soybean oil in aqueous medium for biodiesel production. The two lipase genes were cloned from fungal strains Rhizomucor miehei and Penicillium cyclopium, and each expressed successfully in Pichia pastoris. Activities of the 1,3-specific lipase from R. miehei (termed RML) and the non-specific mono- and diacylglycerol lipase from P. cyclopium (termed MDL) were 550U and 1545U per ml respectively, and enzymatic properties of these supernatant of fermentation broth (liquid lipase) were stable at 4°C for >3 months. Under optimized conditions, the ratio of biodiesel conversion after 12h at 30°C, using RML alone, was 68.5%. When RML was assisted by addition of MDL, biodiesel conversion ratio was increased to >95% under the same reaction conditions. The results suggested that combination of lipases with different specificity, for enzymatic conversion of more complex lipid substrates, is a potentially useful strategy for biodiesel production. [ABSTRACT FROM AUTHOR]