Influence of temperature fluctuations on Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium in cow manure

The effects of four average temperatures (7, 16, 23 and 33 degrees C) and daily oscillations with three amplitudes (0, +/-4, +/-7 degrees C) on the survival of the enteropathogens Escherichia coli O157:H7 and Salmonella serovar Typhimurium were investigated in small microcosms. Manure was inoculated with a green fluorescent protein transformed strain of either pathogen at 10(7) cells g(-1) dry weight. Samples were collected immediately after inoculation, and 1 and 2 weeks after inoculation for E. coli O157:H7, and immediately and after 2 and 3 weeks for Salmonella serovar Typhimurium. Population densities were determined by dilution plating and direct counting. In addition, total bacterial CFUs were determined. Growth and survival data were fitted to a modified logistic model. Analysis of the estimated parameter values showed that E. coli O157:H7 survived for shorter periods of time and was more sensitive to competition by the native microbial community than Salmonella serovar Typhimurium. Survival of both pathogens significantly declined with increasing mean temperatures and with increasing amplitude in daily temperature oscillations. The results indicated that responses of enteropathogens to fluctuating temperatures cannot be deduced from temperature relationships determined under constant temperatures.     

TPK1, a Ca(2+)-regulated Arabidopsis vacuole two-pore K(+) channel is activated by 14-3-3 proteins

The vacuole represents a pivotal plant organelle for management of ion homeostasis, storage of proteins and solutes, as well as deposition of cytotoxic compounds. Ion channels, pumps and carriers in the vacuolar membrane under control of cytosolic factors provide for ionic and metabolic homeostasis between this storage organelle and the cytoplasm. Here we show that AtTPK1 (KCO1), a vacuolar membrane localized K(+) channel of the TPK family, interacts with 14-3-3 proteins (general regulating factors, GRFs). Following in planta expression TPK1 and GRF6 co-localize at the vacuolar membrane. Co-localization of wild-type TPK1, but not the TPK1-S42A mutant, indicates that phosphorylation of the 14-3-3 binding motif of TPK1 represents a prerequisite for interaction. Pull-down assays and surface plasmon resonance measurements revealed GRF6 high-affinity interaction with TPK1. Following expression of TPK1 in yeast and isolation of vacuoles, patch-clamp studies identified TPK1 as a voltage-independent and Ca(2+)-activated K(+) channel. Addition of 14-3-3 proteins strongly increased the TPK1 activity in a dose-dependent manner. However, an inverse effect of GRF6 on the activity of the slow-activating vacuolar (SV) channel was observed in mesophyll vacuoles from Arabidopsis thaliana. Thus, TPK1 seems to provide for a Ca(2+)- and 14-3-3-sensitive mechanism capable of controlling cytoplasmic potassium homeostasis in plants.     

Qualitative analysis of products formed during the acid catalyzed liquefaction of bagasse in ethylene glycol

Bagasse was liquefied in ethylene glycol (EG) catalyzed by sulfuric acid at 190 degrees C under atmospheric pressure. The compositions of the crude products obtained were analyzed after separating them into three fractions: a water-soluble fraction, an acetone-soluble fraction and a residue. With infrared, gel permeation chromatography and elemental analyses, the residue mainly included undissolved cellulose and lignin derivatives and the acetone-soluble fraction mainly contained lignin degradation products with high molecular weights. The water-soluble fraction, after further analyzed by GC-MS and HPLC, showed EG, diethylene glycol, EG derivatives, saccharides, alcohols, aldehydes, ketones, phenols, especially some acids such as formic acid, levulinic acid, acetic acid, oxalic acid and 2-hydroxy-butyric acid and their esters. The Higher Heating Value (HHV) of the residue and the acetone-soluble fractions were higher than that of bagasse. The results showed that some useful chemicals and biofuels could be obtained by this process.     

The Burkholderia cepacia bceA gene encodes a protein with phosphomannose isomerase and GDP-D-mannose pyrophosphorylase activities

The bceA gene is part of the Burkholderia cepacia IST408 exopolysaccharide (EPS) biosynthetic cluster. It encodes a 55.3-kDa bifunctional protein (type II PMI family) with phosphomannose isomerase (PMI) and GDP-mannose pyrophosphorylase (GMP) activities. GMP activity is strongly dependent on the presence of Ca(2+) or Mn(2+), while PMI activity can use a broader variety of divalent cations (Ca(2+)>Mn(2+)>Mg(2+)>Co(2+)>Ni(2+)). The lack of a functional bceA gene does not affect EPS production yield in a non-polar insertion bceA mutant. The in silico search for putative bceA homologues revealed the presence of 2-5 bceA orthologues in the Burkholderia genomes available. This suggests that in B. cepacia IST408 putative bceA functional homologues may compensate the bceA mutation. However, the viscosity of aqueous solutions prepared with the EPS produced by the bceA mutant was significantly reduced compared with wild-type biopolymer and the mutant forms biofilms with a size reduced by 6-fold.     

Oligomeric alpha-synuclein inhibits tubulin polymerization

Earlier investigations have demonstrated that tubulin co-localizes with alpha-synuclein in Lewy bodies and influences the formation of alpha-synuclein aggregation. However, it is not clear whether aggregated alpha-synuclein has any effects on the function of tubulin, i.e. tubulin polymerization, a critical mechanism by which neurons maintain their morphology and execute functions. In this study, we evaluated the effects of aggregated alpha-synuclein on tubulin polymerization in dopaminergic neurons (MES cells), along with mitochondrial function, cell morphology, and viability. The results indicate that MES cells exposed to extracellular oligomeric alpha-synuclein exhibited decreased tubulin polymerization and mitochondrial function as well as morphological alternation long before cell death. Further investigation showed that internalization of oligomeric alpha-synuclein by neurons appeared to be critical in the process, although direct interaction between tubulin and intracellular oligomeric alpha-synuclein was not necessary. Finally, we demonstrated that neurotoxicity induced by oligomeric alpha-synuclein was largely prevented by overexpressing the neuroprotective protein, DJ-1.     

Human mitochondrial complex I assembly: a dynamic and versatile process

One can but admire the intricate way in which biomolecular structures are formed and cooperate to allow proper cellular function. A prominent example of such intricacy is the assembly of the five inner membrane embedded enzymatic complexes of the mitochondrial oxidative phosphorylation (OXPHOS) system, which involves the stepwise combination of >80 subunits and prosthetic groups encoded by both the mitochondrial and nuclear genomes. This review will focus on the assembly of the most complicated OXPHOS structure: complex I (NADH:ubiquinone oxidoreductase, EC 1.6.5.3). Recent studies into complex I assembly in human cells have resulted in several models elucidating a thus far enigmatic process. In this review, special attention will be given to the overlap between the various assembly models proposed in different organisms. Complex I being a complicated structure, its assembly must be prone to some form of coordination. This is where chaperone proteins come into play, some of which may relate complex I assembly to processes such as apoptosis and even immunity.     

The future of ocean governance

Ocean governance is complex and influenced by multiple drivers and actors with different worldviews and goals. While governance encompasses many elements, in this paper we focus on the processes that operate within and between states, civil society and local communities, and the market, including industry. Specifically, in this paper, we address the question of how to move towards more sustainable ocean governance aligning with the sustainable development goals (SDGs) and the UN Ocean Decade. We address three major risks to oceans that arise from governance-related issues: (1) the impacts of the overexploitation of marine resources; (2) inequitable distribution of access to and benefits from marine ecosystem services, and (3) inadequate or inappropriate adaptation to changing ocean conditions. The SDGs have been used as an underlying framework to develop these risks. We identify five drivers that may determine how ocean governance evolves, namely formal rules and institutions, evidence and knowledge-based decision-making, legitimacy of decision-making institutions, stakeholder engagement and participation, and empowering communities. These drivers were used to define two alternative futures by 2030: (a) ‘Business as Usual’—a continuation of current trajectories and (b) ‘More Sustainable Future’—optimistic, transformational, but technically achievable. We then identify what actions, as structured processes, can reduce the three major governance-related risks and lead to the More Sustainable Future. These actions relate to the process of co-creation and implementation of improved, comprehensive, and integrated management plans, enhancement of decision-making processes, and better anticipation and consideration of ambiguity and uncertainty.