Review: Pig-based bioconversion: the use of former food products to keep nutrients in the food chain

The primary challenge of agriculture and livestock production is to face the growing competition between food, feed, fibre, and fuel, converting them from resource-intensive to resource-efficient. A circular economy approach, using agricultural by-products/co-products, in the livestock production system would allow to reduce, reuse, and redistribute the resources. Former food products (FFPs), also named ex-foods, could represent a valid option in strengthening resilience in animal nutrition. FFPs have a promising potential to be included regularly in animal diets due to their nutritive value, although their potential in animal nutrition remains understudied. A thorough investigation of the compositional and dietary features, thus, is essential to provide new and fundamental insights to effectively reuse FFPs as upgraded products for swine nutrition. Safety aspects, such as the microbial load or the presence of packaging remnants, should be considered with caution. Here, with a holistic approach, we review several aspects of FFPs and their use as feed ingredients: the nutritional and functional evaluation, the impact of the inclusion of FFPs in pigs' diet on growth performance and welfare, and further aspects related to safety and sustainability of FFPs.

Is kinesiophobia a predictor of early functional performance after total hip replacement? A prospective prognostic cohort study

Background

Considerable attention has been paid to the role of kinesiophobia with respect to knee prosthesis but it has not yet been studied as a prognostic factor of short-term functional performance following total hip replacement. The main purpose of the present study is to examine the possible predictors of early functional performance of patients undergoing total primary hip arthroplasty, including demographics as age, sex and body mass index, preoperative functional ability, type of anaesthesia, level of haemoglobin, pain and level of kinesiophobia before surgery. Secondly, we want to describe the main characteristics of the population with the highest levels of kinesiophobia.

Methods

A prospective, prognostic cohort study was carried out. Patients undergoing primary hip replacement were recruited consecutively. The main outcome is the early functional performance achieved by patients after surgery and measured using the Iowa Level of Assistance (ILOA) scale on the fifth postoperative day. Preoperative kinesiophobia was measured by the Tampa Scale and the preoperative functional ability by the Western Ontario and McMaster Osteoarthritis Index (WOMAC). The multivariate analysis was performed by the General Linear Model. The analysis of the population with high levels of kinesiophobia was conducted by identifying a cut-off of 40 compared to the Tampa Scale.

Results

Statistical analysis was performed on 269 patients. The average ILOA score recorded was 19.5 (DS 8.3). The levels of kinesiophobia, showed an average score of 35.1 (7.8) and it was not associated with early functional performance. The independent predictive factors include age, sex and body mass index. Kinesiophobia high levels were recorded in 30% of the population and this population had a higher level of pre-operative WOMAC score.

Conclusions

Early functional performance after hip replacement surgery was not correlated with the level of kinesiophobia. Three significant factors that describe a population most at risk of not achieving optimal functional performance are increased age, being female and increase in body mass index. In the preoperative phase, high levels of kinesiophobia were associated with more impaired preoperative functional ability.

Trial registration

Current Controlled Trials NCT02786121, May 2016. Retrospectively registered.

Crystal structure of HydF scaffold protein provides insights into [FeFe]-hydrogenase maturation

[FeFe]-hydrogenases catalyze the reversible production of H2 in some bacteria and unicellular eukaryotes. These enzymes require ancillary proteins to assemble the unique active site H-cluster, a complex structure composed of a 2Fe center bridged to a [4Fe-4S] cubane. The first crystal structure of a key factor in the maturation process, HydF, has been determined at 3 Å resolution. The protein monomer present in the asymmetric unit of the crystal comprises three domains: a GTP-binding domain, a dimerization domain, and a metal cluster-binding domain, all characterized by similar folding motifs. Two monomers dimerize, giving rise to a stable dimer, held together mainly by the formation of a continuous β-sheet comprising eight β-strands from two monomers. Moreover, in the structure presented, two dimers aggregate to form a supramolecular organization that represents an inactivated form of the HydF maturase. The crystal structure of the latter furnishes several clues about the events necessary for cluster generation/transfer and provides an excellent model to begin elucidating the structure/function of HydF in [FeFe]-hydrogenase maturation.

Stoichiometry of LHCI antenna polypeptides and characterization of gap and linker pigments in higher plants Photosystem I

We report on the results obtained by measuring the stoichiometry of antenna polypeptides in Photosystem I (PSI) from Arabidopsis thaliana. This analysis was performed by quantification of Coomassie blue binding to individual LHCI polypeptides, fractionation by SDS/PAGE, and by the use of recombinant light harvesting complex of Photosystem I (Lhca) holoproteins as a standard reference. Our results show that a single copy of each Lhca1-4 polypeptide is present in Photosystem I. This is in agreement with the recent structural data on PSI-LHCI complex [Ben Shem, A., Frolow, F. and Nelson, N. (2003) Nature, 426, 630-635]. The discrepancy from earlier estimations based on pigment binding and yielding two copies of each LHCI polypeptide per PSI, is explained by the presence of 'gap' and 'linker' chlorophylls bound at the interface between PSI core and LHCI. We showed that these chlorophylls are lost when LHCI is detached from the PSI core moiety by detergent treatment and that gap and linker chlorophylls are both Chl a and Chl b. Carotenoid molecules are also found at this interface between LHCI and PSI core. Similar experiments, performed on PSII supercomplexes, showed that dissociation into individual pigment-proteins did not produce a significant loss of pigments, suggesting that gap and linker chlorophylls are a peculiar feature of Photosystem I.

cor Gene expression in barley mutants affected in chloroplast development and photosynthetic electron transport

The expression of several barley (Hordeum vulgare) cold-regulated (cor) genes during cold acclimation was blocked in the albino mutant a(n), implying a chloroplast control on mRNAs accumulation. By using albino and xantha mutants ordered according to the step in chloroplast biogenesis affected, we show that the cold-dependent accumulation of cor14b, tmc-ap3, and blt14 mRNAs depends on plastid developmental stage. Plants acquire the ability to fully express cor genes only after the development of primary thylakoid membranes in their chloroplasts. To investigate the chloroplast-dependent mechanism involved in cor gene expression, the activity of a 643-bp cor14b promoter fragment was assayed in wild-type and albino mutant a(n) leaf explants using transient beta-glucuronidase reporter expression assay. Deletion analysis identified a 27-bp region between nucleotides -274 and -247 with respect to the transcription start point, encompassing a boundary of some element that contributes to the cold-induced expression of cor14b. However, cor14b promoter was equally active in green and in albino a(n) leaves, suggesting that chloroplast controls cor14b expression by posttranscriptional mechanisms. Barley mutants lacking either photosystem I or II reaction center complexes were then used to evaluate the effects of redox state of electron transport chain components on COR14b accumulation. In the mutants analyzed, the amount of COR14b protein, but not the steady-state level of the corresponding mRNA, was dependent on the redox state of the electron transport chain. Treatments of the vir-zb63 mutant with electron transport chain inhibitors showed that oxidized plastoquinone promotes COR14b accumulation, thus suggesting a molecular relationship between plastoquinone/plastoquinol pool and COR14b.