Multitechnique study on a recombinantly produced Bacillus halodurans laccase and an S-layer/laccase fusion protein

Methods for organizing functional materials at the nanometer scale are essential for the development of novel fabrication techniques. One of the most relevant areas of research in nanobiotechnology concerns technological utilization of self-assembly systems, wherein molecules spontaneously associate into reproducible supramolecular structures. For this purpose, the laccase of Bacillus halodurans C-125 was immobilized on the S-layer lattice formed by SbpA of Lysinibacillus sphaericus CCM 2177 either by (i) covalent linkage of the enzyme to the natural protein self-assembly system or (ii) by construction of a fusion protein comprising the S-layer protein and the laccase. The laccase and the S-layer fusion protein were produced heterologously in Escherichia coli. After isolation and purification, the properties of the proteins, as well as the specific activity of the enzyme moiety, were investigated. Interestingly, the S-layer part confers a much higher solubility on the laccase as observed for the sole enzyme. Comparative spectrophotometric measurements of the enzyme activity revealed similar but significantly higher values for rLac and rSbpA/Lac in solution compared to the immobilized state. However, rLac covalently linked to the SbpA monolayer yielded a four to five time higher enzymatic activity than rSbpA/Lac immobilized on a solid support. Combined quartz crystal microbalance with dissipation monitoring (QCM-D) and electrochemical measurements (performed in an electrochemical QCM-D cell) revealed that rLac immobilized on the SbpA lattice had an approximately twofold higher enzymatic activity compared to that obtained with the fusion protein.     

Infectious agent from a free-living soil amoeba, Naegleria gruberi

A subcellular infectious material has been found in a strain of the amoeba Naegleria gruberi, strain EG, which is capable of infecting chick embryo cells and causing them to undergo cytopathic changes with the release of more infectious material. The material is present in two lines of the amoeba which were separated shortly after the isolation of the strain and subsequently maintained in separate laboratories.     

Marihuana: standardized smoke administration and dose effect curves on heart rate in humans

A spirometer was used to deliver marihuana and placebo smoke to human subjects. This procedure produced linear dose-effect curves on heart rate and replicable dose effects in individual subjects. No differences were observed between experienced and inexperienced smokers in responsiveness to heart rate increases produced by marihuana.     

Observation of Berry's phase in a solid-state qubit

In quantum information science, the phase of a wave function plays an important role in encoding information. Although most experiments in this field rely on dynamic effects to manipulate this information, an alternative approach is to use geometric phase, which has been argued to have potential fault tolerance. We demonstrated the controlled accumulation of a geometric phase, Berry's phase, in a superconducting qubit; we manipulated the qubit geometrically by means of microwave radiation and observed the accumulated phase in an interference experiment. We found excellent agreement with Berry's predictions and also observed a geometry-dependent contribution to dephasing.     

Absorption,translocation and distribution of lindane and DDT in the corn plant

Summary Data are given on the translocation and distribution of lindane and DDT in corn plants, and on their accumulation in corn kernels.The studies were conducted between 1966 and 1968, using emulsifiable products containing lindane and DDT formulated according to the same formulation. The insecticides were introduced in the plant by absorption from the soil and by injection.A part of the internodes of the 5 plants, representing a variant, were analysed. From the data obtained it results that insecticide absorption in the plants varies in terms of the date of application, and the rate of plant development.Following plant injections, DDT accumulated in larger amounts than lindane and, conversely, by absorption from the soil lindane was absorbed in larger quantities.It was found that both lindane and DDT are able to translocate and accumulate in corn plants and kernels. This translocation is higher for lindane and less so for DDT. In the case of lindane, an accumulation at the level of the physiologically active plant centers was established.Compound accumulation in a larger or smaller proportion is also a function of the water regime,, and their localization in various zones of the plant probably is governed by some physiological factors.

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Zusammenfassung Daten über Translokation und Verteilung von Lindan und DDT in der Maispflanze sowie über Anreicherung in den Maiskörnern werden mitgeteilt.Die Forschungsarbeiten wurden in den Jahren 1966–1968 durchgeführt. Als Versuchspräparate dienten emulgiertes Lindan und nach der gleichen Formulierung hergestellte DDT-Emulsion.Die Insektizide wurden der Pflanze auf zwei verschiedenen Wegen zugeführt, und zwar durch Bodenabsorption und durch Injektion.Die Internodien der 5 Pflanzen, die eine Variante bildeten, wurdern auf Rückstände analysiert.Auf Grund der erzielten Resultate wird festgestellt, daß die Insektizidaufnahme durch die Pflanze von ihrem Entwicklungsstadium und von dem Behandlungstermin abhängig ist.Von den injizierten Insektiziden wurden in der Pflanze größere DDT-Mengen gespeichert, während durch Bodenabsorption größere Mengen Lindan von der Pflanze aufgenommen wurden.Es wird weiterhin festgestellt, daß sowohl Lindan als auch DDT in der Maispflanze bis in die Körner weitergeleitet und gespeichert werden kann. Bei Lindan ist die Translokation intensiver als bei DDT.Größere Lindananreicherungen wurden im Bereich der physiologisch aktiven Pflanzenzentren festgestellt.Größere oder geringere Anreicherungen von Insektiziden in der Pflanze hängen auch von ihrem Wasserhaushalt ab, während die Lokalisierung in den einzelnen Pflanzenzonen von bestimmten physiologischen Faktoren abhängig ist.

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Résumé On présente des données sur la translocation et la répartition du lindane et du DDT dans la plante de maïs, et sur leur accumulation dans les graines.Les recherches ont été effectuées de 1966 à 1968, en utilisant des produits émulsifiables contenant du lindane et du DDT, conditionnés selon la même formulation.Les insecticides ont été introduits dans la plante soit par absorbtion, soit par des injections.On a analysé partiellement les internodes des 5 plantes qui ont constitué une variante.Les données obtenues montrent que l'absorbtion des insecticides dans la plante varie en fonction du moment de l'application du traitement et en rapport avec le degré de développement de la plante.A la suite des injections, le DDT a été accumulé en plus grande quantité que le lindane et, au contraire, l'accumulation du lindane a été plus importante à la suite de l'absorbtion à partir du sol.On constate que le lindane et le DDT peuvent être transloqués et accumulés dans les plantes et les graines de maïs. Cette translocation est plus importante chez le lindane, et elle est moindre dans le cas du DDT. En ce qui concerne le lindane, on constate des accumulations au niveau des centres physiologiquement actifs de la plante.L'accumulation en une proportion plus ou moins grande est aussi conditionnée par le régime de l'eau, cependant que la localisation de ces substances dans diverses zones de la plante est déterminée par certains facteurs physiologiques.

     

Reduction of nitrogen losses in agriculture by fertilizer additives: Appeal for more detailed scientific work—Comments on Guo et al. “Efficacy of four nitrification inhibitors for the mitigation of nitrous oxide emissions under different soil temperature and moisture,” Journal of Plant Nutrition and Soil Science (2022), 185(1), 60–68

In Guo et al. (2022), the difference between pure nitrification inhibitors (NI), fertilizers treated with NI, and formulations containing NI was insufficiently considered. Presented results are misleading and inappropriate to evaluate the efficiency of an NI application by pure NI as well as NI-treated products such as ENTEC^® 26 and PIADIN^®, in particular with respect to practical field conditions.     

Tree growth stresses—Part IV: Visco-elastic strain recovery

Summary Experimental methods for the determination of visco-elastic strain recoveries in timber are described. Intensive studies were carried out on Eucalyptus regnans F. Muell., to determine the characteristics of visco-elastic, longitudinal strain recovery, and its distribution along radial limes, in wood from butt, middle and top logs of trees; and also to investigate the effect on strain recovery of different diameters of trees and tree ages. Much less extensive tests, made on three other eucalyptus species and on Pinus radiata D. Don, were undertaken to explore the possibility of strong species differences. It was found that the total visco-elastic strain recovery varied from maximum tensile values near the bark, through zero to maximum compressive values near the pit. It followed an exponential-rate curve commencing immediately after elastic strain release. Increments after 14 days were rarely measurable. An effect of increasing recoveries with age was proved highly significant. Large differences in recovery were evident between the softwood and the hardwood species. The authors wish to acknowledge the valuable assistance of the Division of Mathematical Statistics, CSIRO. In particular, their thanks are due to Miss N. Ditchburne of that Division, especially in connection with estimates of the significance of trends in the data. They also acknowledge the helpful suggestions of Dr. P. U. A. Grossman of this Division, that led to the theoretical development given in Appendix III.