Significance and Impact of the Study: Although catfishes are not classified as true xylivores, inhabiting their faeces are bacteria that may provide a novel source of cellulolytic enzyme. Based on this first microbiology study, the faeces and thus the gastrointestinal microbiome of Panaque catfishes are an unexplored reservoir of microbial extracts with enhanced polysaccharide transforming enzyme activity. The biomimetical exploitation of this cellulolytic activity in the form of novel enzymes or by applying a mixture of cellulolytic micro-organisms could accomplish a pretreatment to the mechanical production process of nanocellulose fibres, thus could reduce the energy consumption costs significantly. AbstractCatfishes of the genus Panaque are known for their ability to feed on wood and hence to process cellulose fibres in their digestive systems. The paper industry uses cellulose fibres and thus has an interest in exploiting this property biomimetically: it could be employed as a pretreatment to lessen the energy required by the mechanical production stage of manufacturing nanocellulose fibres. Here, we characterize the diet-associated in situ microbial diversity and population dynamic in the faeces of catfish (Panaque sp.) exposed to consecutive diets of pellet food and then wood. Fish faeces samples were collected and investigated by parallel DNA deep amplicon sequencing of the bacterial 16S rRNA SSU for both diet conditions. The most frequently occurring bacterium in the faeces was Cetobacterium sp. The dominant cellulolytic bacterial genera found in ascending relative abundance were as follows: Aeromonas sp., Flavobacterium sp., Bacteroides sp., Pseudomonas sp. and Cellvibrio sp. Diet-associated changes in the faeces microbiome were noted for Flavobacterium sp. Extensive microbial diversity was found in catfish faeces, evidenced using culture-independent molecular techniques. No significant dietassociated effects on the microbiome in terms of biodiversity were observed in the catfish faeces, but diet-associated changes in the microbial population structure were observed.

The flow in a confined container induced by an ultrasonic horn is measured by Particle Image Velocimetry (PIV). This flow is caused by acoustic streaming and highly influenced by the presence of cavitation. The jet-like experimentally observed flow is compared with the available theoretical solution for a turbulent free round jet. The similarity between both flows enables a simplified numerical model to be made, whilst the phenomenon is very difficult to simulate otherwise. The numerical model requires only two parameters, i.e. the flow momentum and turbulent kinetic energy at the position of the horn tip. The simulated flow is used as a basis for the calculation of the time required for the entire liquid volume to pass through the active cavitation region.

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In this work, stability of dispersions and foams containing CaCO3-based pigments and cellulose nanofibrils (CNF) was evaluated with the aim to reveal the mechanisms contributing to the overall stability of the selected systems. The utmost interest lies in the recently developed hydrocolloid hybrid CaCO3 pigments and their potential to form bionanocomposite structures when incorporated with CNF. These pigments possess a polyelectrolyte layer deposited on the surface of the particle which is expected to enhance the compatibility between inorganic and organic components. Stability assessment of both dispersions and foams was conducted using turbidity profile scanning. In dispersions, CNF provides stability due to its ability to form a firm percolation network. If surface-modified pigments are introduced, the favourable surface interactions between the pigments and CNF positively influence the stability behaviour and even large macro-size pigments do not interfere with the stability of either dispersions or foams. In foams, the stability can be enhanced due to the synergistic actions brought by CNF and particles with suitable size, shape and wetting characteristics resulting in a condition where the stability mechanism is defined by the formation of a continuous plateau border incorporating a CNF network which is able to trap the inorganic particles uniformly.

An organoplatinum precursor enables electroless deposition of platinum coatings, films, and mirrors on natural materials, synthetic polymers, metals, and ceramics by simply heating the precursor solution to temperatures of 80 °C or above. The films are comprised of densely packed platinum nanoparticles of 1-5 nm in size; they are flexible and electrically conducting and have pore sizes in the nanometer range.

Micro and nanofibrillated cellulose in aqueous suspension presents many challenges when considering its use, for example, in forming nanocomposites. The inclusion of filler particles either as extender or as functional additive allows the range of strength and deformation properties to be extended. These properties, however, are linked in many cases to the rheological properties of the raw material mix. Interactions under dynamic shear or under controlled stress at low amplitude reveal the potential to generate functional interactions, not only between the cellulose components themselves but also between the cellulose and polymer additives, as well as surface modified pigment fillers. Examples are given demonstrating the action of adding cellulosic polymer in the form of carboxymethyl cellulose (CMC) to micro and nanofibrillated cellulose (MNFC). Rheological studies show how these combinations with CMC, added either in free form or preadsorbed onto calcium carbonate filler particles, lead to a variety of responses. Dispersability of the MNFC is increased by the use of free CMC polymer addition, and the usually expected flocculating action on added filler is seen not to occur. Alternatively, the preadsorbed CMC on the calcium carbonate pigment filler leads to an interaction between the fibrillar cellulose and the surface modified calcium carbonate pigment filler, to which incorporation of cationic polymer leads to a reduction of interaction, provided theaddition level does not exceed the isoelectric point of the mix. The observations are viewed in the context of a combination of proposed physical contact dynamics in the form of disordered and ordered alignment.

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