The influence of copper on alkaline protease stability toward autolysis and thermal inactivation

Alkaline proteases are one of the most important group of enzymes that are indispensable in a number of different industrial sectors. In this work, the effect of copper ions (Cu²⁺) was investigated for improving the thermostability and hydrolytic performance of Bacillus clausii GMBE 42 alkaline protease at different temperatures (45–65°C). Maximal residual activity was observed in the presence of 5 mM CuCl₂. The enzyme was thermoinactivated according to first‐order kinetics. A stabilization effect caused by copper ions was the result of a decrease in both autolysis and thermoinactivation rates. Thermodynamic analysis of the thermoinactivation process showed that E_a,i, ΔG_i, and ΔH_i values of the enzyme were higher in the presence of copper ions, but there was no measurable change in ΔS_i values. These results show the thermostabilizing potential of copper ions on the enzyme. Lower K_m values and higher k_cat and k_cat/K_m values were obtained in the presence of copper ions, which is an indication of the nonessential activation of the enzyme by copper ions. Thermodynamic analysis of casein hydrolysis showed that in presence of copper ions E_a, ΔG^≠, ΔH^≠, , and values of enzyme were lower, but there was no change in ΔS^≠ values. This is so far the first study that investigates the effect of cations on the basic catalytic and thermodynamic properties of an alkaline serine protease, which may be used to remove protein wastes from various industries such as food and leather processing.     

Tree-ring growth of Pinus nigra Arn. subsp. pallasiana under different climate conditions throughout western Anatolia

Pinus nigra Arn. subsp. pallasiana (black pine) is one of the most widely grown tree in Turkey. It is the third most widely distributed tree species after Quercus L. and Pinus brutia Ten. Black pine grows in 20% of all forested areas in Turkey. In this dendroecological study, we identified the most important climate factors affecting radial growth of black pine in western Anatolia and classified its responses to climate. Twenty-eight site chronologies developed by different researchers were used in the analysis. Response functions were calculated for each chronology to identify the effect of climate on radial growth. Hierarchical cluster analysis was used to sort response functions and to classify the chronologies into groups based on climate responses. The individual responses of these chronologies to temperature and precipitation were classified in four main groups. Climatic and phytogeographic differences were the major factors influencing the formation of clusters. The results suggest that the major limiting factor is drought caused by low precipitation, especially in May, in almost all sites. The drought effect is much stronger in the transition region to the steppe, Central Anatolia and Mediterranean Regions than the Black Sea Region. Black pine trees respond positively to higher temperature at the beginning of growing season in almost all areas except in transition region to the steppe.     

Fuzzy Multi-Objective Optimization of a Green Supply Chain Network with Risk Management that Includes Environmental Hazards

Among the leading environmental risks, global climate alteration has become one of the most important controversial issues. Greenhouse gas emissions (CO₂, methane, etc.) and air pollution have motivated a need to develop and improve environmental management strategies. As a consequence, environmental sanctions are forcing commercial enterprises to re-consider and re-design supply chain processes in a green way. This article provides a multi-objective model to design a closed-loop supply chain (CLSC) network in a green framework. Our first and second objectives are to minimize all the transportation costs for the supply chain's forward and reverse logistics; the third objective is to minimize total CO₂ emissions; the fourth objective is to encourage customers to use recyclable materials as an environmental practice. To provide more realistic modeling by treating the uncertainty in decision-makers’ objectives, fuzzy modeling is used in this study. The model is explained and tested via fulfilling a numerical example. In scenario analyses, analytic hierarchy process (AHP), fuzzy AHP (F-AHP), and fuzzy TOPSIS (F-TOPSIS) approaches were applied and compared to evaluate different objectives to guide decision-makers.     

Chemical composition and antifungal effect of anise (Pimpinella anisum L.) fruit oil at ripening stage

The composition of the essential oil ofPimpinella anisum L fruit is determined by GC and GC-MS. The volatile oil content obtained by hydrodistillation was 1.91%. Ten compounds representing 98.3% of the oil was identified. The main constituents of he oil obtained from dried fruits were trans-a nethole (93.9%) and estragole (2.4%). The olfactorially valuable constituents that were found with concentration higher than 0.06% were (E)-methyeugenol, α-cuparene, α-himachalene, β-bisabolene, p-anisaldehyde and cis-anethole. Also, the different concentrations of anise oil exerted varying levels of inhibitory effects on the mycelial growth off/ternaria alternata, Aspergillus niger andAspergillus parasiticus used in experimental. The results showed that the most effected fungus from anise oil wasA. parasiticus, which is followed byA. niger andA. alternata. Individual of this plant oil may provide a useful to achive adequate shelf-life of foods.     

Oxygen consumption of the aquatic leaf beetles Macroplea mutica and Macroplea appendiculata is low and not influenced by salinity

Leaf beetles of the genus Macroplea live permanently under water. Species‐specific preferences for either freshwater or brackish water are available in the literature. To detect potential physiological differences, the oxygen consumption of Macroplea mutica and Macroplea appendiculata from habitats with differing salinities is measured at two different salinities (0 and 10). The specific oxygen consumption does not depend on oxygen saturation of the water (values in the approximate range of 25–100% occur during the experiments). There is no difference between species or sampling locations. Similarly, the salinity during the measurements does not affect the oxygen consumption of the beetles, either when compared as salinity per se (0 versus 10), or when classified as home salinity or atypical salinity. Comparisons with other chrysomelid beetles and aquatic insects (using available published data) reveal that the two Macroplea species have relatively low metabolic rates. This finding is discussed in the light of activity patterns and morphology, especially the reduction of flight muscles, which comprise a highly metabolically active tissue.     

Distribution of individual members of the mosquito Anopheles maculipennis complex in Germany identified by newly developed real‐time PCR assays

Owing to their role as vectors of malaria parasites, species of the Anopheles maculipennis complex (Diptera: Culicidae) Meigen were intensively studied in the past, but with the disappearance of malaria in Germany in the middle of the last century, the interest in this field of research declined. A comprehensive ecological analysis of the current species distribution for Germany is lacking. Between 2010 and 2013, a total of 1445 mosquitoes of the An. maculipennis complex were collected at 72 different sites in Germany. The samples comprise 722 single individuals as well as 723 individuals in 90 pools of up to 25 mosquitoes. All samples were analysed with newly developed species‐specific qPCR assays for the identification of the four German species using nucleotide differences within the internal transcribed spacer 2 (ITS2) ribosomal DNA. All gathered data were used for species distribution modelling. The overall prevalence of An. messeae s.l. was highest with 98.89% of all pools; An. daciae with 6.93% of all individuals and An. messeae s.s. with 69.53%. The prevalence of the other two species was relatively low: An. maculipennis s.s. with 13.30% of all individuals (6.67% of all pools) and An. atroparvus with 1.80% of all individuals (1.11% of all pools).     

Host preferences in host‐seeking and blood‐fed mosquitoes in Switzerland

The avian zoonotic agent for West Nile virus (WNV) can cause neuroinvasive disease in horses and humans and is expanding its range in Europe. Analyses of the risk for transmission to these hosts in non‐endemic areas are necessary. Host preferences of mosquitoes (Diptera: Culicidae), the main vectors of WNV, were determined in Switzerland using animal‐baited trap (horse, chickens) experiments at a natural and a periurban site. This was undertaken on four occasions during May–September 2014. In addition, the hosts of 505 blood‐fed mosquitoes collected in a zoo and in the field were determined. Mosquito data obtained in the animal bait experiments were corrected for host weight and body surface area and by Kleiber's scaling factor. Collections of 11–14 different mosquito species were achieved with these approaches. Statistically significant host preferences were identified in three species in both approaches. The other species showed opportunistic feeding behaviours to varying extents. Specifically, the invasive species Hulecoeteomyia japonica (= Aedes japonicus) was identified for the first time as feeding on avians in nature. Abundance data, spatiotemporal activity and laboratory vector competence for WNV suggested that, in addition to the main WNV vector Culex pipiens, H. japonica and Aedimorphus vexans (= Aedes vexans) are the most likely candidate bridge vectors for WNV transmission in Switzerland.