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Amylases are probably the best studied glycoside hydrolases and have a huge biotechnological value for industrial processes on starch. Multiple amylases from fungi and microbes are currently in use. Whereas bacterial amylases are well suited for many industrial processes due to their high stability, fungal amylases are recognized as safe and are preferred in the food industry, although they lack the pH tolerance and stability of their bacterial counterparts. Here, we describe three amylases, two of which have a broad pH spectrum extending to pH 8 and higher stability well suited for a broad set of industrial applications. These enzymes have the characteristic GH13 α-amylase fold with a central (β/α)8-domain, an insertion domain with the canonical calcium binding site and a C-terminal β-sandwich domain. The active site was identified based on the binding of the inhibitor acarbose in form of a transglycosylation product, in the amylases from Thamnidium elegans and Cordyceps farinosa. The three amylases have shortened loops flanking the nonreducing end of the substrate binding cleft, creating a more open crevice. Moreover, a potential novel binding site in the C-terminal domain of the Cordyceps enzyme was identified, which might be part of a starch interaction site. In addition, Cordyceps farinosa amylase presented a successful example of using the microseed matrix screening technique to significantly speed-up crystallization.

Abstract Background A capable expression vector is mainly characterized by its production efficiency, stability and induction response. These features can be influenced by a variation of modifications and versatile genetic modules. Results We examined miscellaneous variations of a rhaPBAD expression vector. The introduction of a stem loop into the translation initiation region of the rhaPBAD promoter resulted in the most significant improvement of eGFP expression. Starting from this plasmid, we constructed a set of expression vectors bearing different genetic modules like rop, ccdAB, cer and combinations thereof, and tested the efficiency of expression and plasmid stability. The plasmid pWA21, containing the stem loop, one cer site and rop, attained high expression levels accompanied by a good stability, and on that score seems to be a well-balanced choice. Conclusion We report the generation of variations of the rhaPBAD expression vector and characterization hereof. The genetic modules showed a complex interplay, therefore two positive effects combined sometimes resulted in a disadvantage.

Rhodiola, belonging to the Crassulaceae family, is a perennial herbaceous plant genus. There are about 90 Rhodiola species worldwide, some of which have been reported to have medicinal properties. Rhodiola sachalinensis is a perennial medicinal herb within this genus and, in the present study, its chloroplast genome was sequenced, assembled, annotated and compared with 24 other Rhodiola species. The results obtained show that the chloroplast genome of R. sachalinensis is 151 595 bp long and has a CG content of 37.7%. The inverted repeats (IR) region of the Rhodiola chloroplast genome is the most conserved region, with the main differences being observed in the ycf1 and ndhF genes at the IRb‐small single copy boundary, and rps19 and trnH genes at the IRa‐large single copy boundary. Phylogenetic analysis showed that Rhodiola species form two major clades, and species with recorded medicinal properties, clustered together in one branch except for R. dumulosa. Within the genus, R. sachalinensis is most closely related to Rhodiola rosea, although comparative analyses showed that only R. sachalinensis and Rhodiola subopposita contained the psbZ gene, which encodes a highly conserved protein subunit of the Photosystem II core complex. Overall, the present study contributes to the understanding of the chloroplast genome of Rhodiola species, and provides a theoretical basis for the study of their genetic diversity and possible use as medicinal plants. [ABSTRACT FROM AUTHOR]

Despite the crucial role of the Southern Hemisphere (SH) westerlies in modulating modern and past climate evolution, little is known about their behavior and possible forcing mechanisms during the early Cenozoic. We probe changes in the hydroclimate of southwest Australia during 62–51 Ma, based on sedimentary proxy records from the International Ocean Discovery Program Site U1514 in the Mentelle Basin. Our results reveal a transition from a less humid climate to wetter conditions at mid–high latitudes starting from the early Eocene, which suggests poleward migration of the SH westerlies. This long‐term trend is punctuated by short‐lived events of aridification during the Mid‐Paleocene Biotic Event and wetter intervals during the Paleocene‐Eocene Thermal Maximum, indicating additional short‐term meridional shifting of the westerlies. We propose that the evolution of SH westerlies was driven by the equator‐to‐pole temperature gradient regulated by global warming and ephemeral growth of the Antarctic ice sheet. Plain Language Summary: The Southern Hemisphere (SH) westerlies, which are the dominant atmospheric circulation patterns in the middle latitudes, play a key role in regulating global and regional climate. Currently, the knowledge of past changes in SH westerlies relies mainly on the late Quaternary. Its dynamics over longer timescales, especially under early Cenozoic greenhouse climate states, remain poorly understood. The Mentelle Basin off southwest Australia was located at a more southerly location than at the present day, and was potentially under the influence of SH westerlies. To examine the long‐term hydroclimate changes in southwest Australia during the mid‐late Paleocene to the early Eocene (62–51 Ma), we measured neodymium and hafnium isotopic compositions of fine‐grained detrital sediments from a borehole (IODP Site U1514) drilled in the Mentelle Basin, in addition to clay mineralogy, and elemental abundances. Our results suggest a gradual wetting of southwest Australia since the early Eocene, which we relate to the poleward migration of SH westerlies in response to a reduced latitudinal temperature gradient. An abrupt northward shift of SH westerlies was observed during the short‐lived Middle Paleocene Biotic Event (∼59 Ma), possibly driven by ephemeral growth of the Antarctica ice sheet. Key Points: We reconstruct the hydroclimate evolution of southwest Australia during 62–51 MaThe Southern Hemisphere (SH) westerlies remained relatively stable during the mid‐late Paleocene and shifted poleward since the early EoceneProcesses related to variations of pole‐equator temperature gradients drove meridional migration of the SH westerlies [ABSTRACT FROM AUTHOR]

In many production facilities, multiple components have to work together to share the overall workload on the entire system, leading to loading dependence and higher vulnerability to cascading failures. Additionally, overloading of one component can expedite the failures of others, exemplifying another form of loading dependence. In this study, we develop a system reliability analysis model for loading dependent systems considering overloads based on the Multi‐state CASCADE model. By incorporating a time variable, the tailor‐made model is able to characterize the duration of each generation in the cascading process, along with the cumulative time of the whole cascading process until the system collapse. A combination of analytical and simulation techniques is then employed to investigate how various potential influencing factors of loading dependence and cascading processes influence the system reliability. The results demonstrate that the effectiveness of proposed method in estimating the system reliability of the loading dependent system considering overloads. Such findings can improve the decision‐makings of reliability prediction, system design, and maintenance optimization, especially in scenarios involving the loading dependent with cascading failures. [ABSTRACT FROM AUTHOR]

There are interactions between surface waves and currents, the latter includes wind-driven current and tidal current. Currents influence surface waves though advection transport and shear instability generation processes. While the horizontal gradient of current is commonly considered to calculate wave-current interaction source term in most wave models, the vertical gradient of current (current shear) has been simplified. In coastal waters, strong background currents with topographic fluctuations at the scale of surface waves have a resonance effect on surface waves. However, this resonance process is currently ignored in existing wave models. To evaluate the effects of current shear and topographic fluctuations on surface waves more accurately, an analytical model is proposed to describe the modification of the amplitude of orbital velocities for surface waves. The amplitude of orbital velocities exhibits significant variations when considering both current shear and topographic fluctuation effects. Wave particle trajectory equations that incorporate current shear and topographic fluctuations are derived based on this analytical model. In deep waters, current shear can increase or decrease the horizontal radius of wave particle trajectory by approximately 0.3 m, while the modification of horizontal amplitude of orbital velocities is about 0.3 m/s. In shallow waters, with both topographic fluctuations and background current present, both horizontal and vertical radii of wave particle trajectory change by approximately ±0.1 m respectively, and the modification of both horizontal and vertical amplitudes of orbital velocities is about 0.2–0.3 m/s. Moreover, in some cases, there are reversals in the direction of wave particle trajectories. [ABSTRACT FROM AUTHOR]

The mannose operon of Bacillus subtilis consists of three genes, manP, manA, and yjdF, which are responsible for the transport and utilization of mannose. Upstream and in the same orientation as the mannose operon a regulatory gene, manR, codes for a transcription activator of the mannose operon, as shown in this study. Both mannose operon transcription and manR transcription are inducible by mannose. The presence of mannose resulted in a 4- to 7-fold increase in expression of lacZ from the manP promoter ([P.sub.manP]) and in a 3-fold increase in expression of lacZ from the manR promoter ([P.sub.manR]). The transcription start sites of manPA-yjdF and manR were determined to be a single A residue and a single G residue, respectively, preceded by -10 and -35 boxes resembling a vegetative [[sigma].sup.A] promoter structure. Through deletion analysis the target sequences of ManR upstream of [P.sub.manP] and [P.sub.manR] were identified between bp -80 and -35 with respect to the transcriptional start site of both promoters. Deletion of manP (mannose transporter) resulted in constitutive expression from both the [P.sub.manP] and [P.sub.manR] promoters, indicating that the phosphotransferase system (PTS) component [EII.sup.Man] has a negative effect on regulation of the mannose operon and manR. Moreover, both [P.sub.manP] and [P.sub.manR] are subject to carbon catabolite repression (CCR). By constructing protein sequence alignments a DNA binding motif at the N-terminal end, two PTS regulation domains (PRDs), and an EIIA- and EIIB-like domain were identified in the ManR sequence, indicating that ManR is a PRD-containing transcription activator. Like findings for other PRD regulators, the phosphoenolpyruvate (PEP)-dependent phosphorylation by the histidine protein HPr via His15 plays an essential role in transcriptional activation of [P.sub.manP] and [P.sub.manR]. Phosphorylation of Ser46 of HPr or of the homologous Crh protein by HPr kinase and formation of a repressor complex with CcpA are parts of the B. subtilis CCR system. Only in the double mutant with an HPr Ser46Ala mutation and a crh knockout mutation was CCR strongly reduced. In contrast, [P.sub.manR] and [P.sub.manP] were not inducible in a ccpA deletion mutant. doi: 10.1128/JB.01673-09

3DOM CdS QDs-N/TiO2 composite was synthesized by CdS quantum dots (QDs) modified on the surface of 3DOM N/TiO2, of which the main component is anatase TiO2. The crystallinity of TiO2 is improved by using polystyrene (PS) colloidal microspheres as the template. The introduction of CdS QDs not only expands the light absorption range of 3DOM N/TiO2, but also a Z-scheme heterojunction optimizing the charge transfer is formed. The results of photoluminescence spectroscopy and electrochemical impedance show that the lifetime of photogenerated charge carrier is prolonged in the composite 3DOM CdS QDs-N/TiO2, and the recombination of photogenerated electron–hole pairs is suppressed effectively. Compared with the main catalyst TiO2, the photocatalytic activity of 3DOM CdS QDs-N/TiO2 is significantly enhanced. In the photohydrogen production experiment, the photohydrogen production capacity of 3DOM CdS QDs-N/TiO2 composite material (2247 μmol·g−1, 8 h) is 172.8 times that of the commercially available P25. After using 2.0 wt% Pt as a co-catalyst, the amount of hydrogen evolution (16,663 μmol·g−1, 8 h) increases ca. 7.4 times. Through capture experiments, the possible photocatalytic reaction mechanism and the reason for the enhanced photocatalytic performance were speculated and discussed. Using polystyrene colloidal microspheres as the template, a three-dimensional ordered macroporous composite 3DOM CdS QDs-N/TiO2 was synthesized by vacuum impregnation and hydrothermal deposition. The quantum effect of CdS QDs, the unique 3DOM structure and the synergy between the Z-type heterojunction further increase the light absorption range of 3DOM CdS QDs-N/TiO2, which show the better perform of multi-mode photocatalytic degradation and photocatalytic hydrogen evolution. [ABSTRACT FROM AUTHOR]