An overview of the utilisation of microalgae biomass derived from nutrient recycling of wet market wastewater and slaughterhouse wastewater

Microalgae have high nutritional values for aquatic organisms compared to fish meal, because microalgae cells are rich in proteins, lipids, and carbohydrates. However, the high cost for the commercial production of microalgae biomass using fresh water or artificial media limits its use as fish feed. Few studies have investigated the potential of wet market wastewater and slaughterhouse wastewater for the production of microalgae biomass. Hence, this study aims to highlight the potential of these types of wastewater as an alternative superior medium for microalgae biomass as they contain high levels of nutrients required for microalgae growth. This paper focuses on the benefits of microalgae biomass produced during the phycore-mediation of wet market wastewater and slaughterhouse wastewater as fish feed. The extraction techniques for lipids and proteins as well as the studies conducted on the use of microalgae biomass as fish feed were reviewed. The results showed that microalgae biomass can be used as fish feed due to feed utilisation efficiency, physiological activity, increased resistance for several diseases, improved stress response, and improved protein retention

The Atlantic salmon genome provides insights into rediploidization

The whole-genome duplication 80 million years ago of the common ancestor of salmonids (salmonid-specific fourth vertebrate whole-genome duplication, Ss4R) provides unique opportunities to learn about the evolutionary fate of a duplicated vertebrate genome in 70 extant lineages. Here we present a high-quality genome assembly for Atlantic salmon (Salmo salar), and show that large genomic reorganizations, coinciding with bursts of transposon-mediated repeat expansions, were crucial for the post-Ss4R rediploidization process. Comparisons of duplicate gene expression patterns across a wide range of tissues with orthologous genes from a pre-Ss4R outgroup unexpectedly demonstrate far more instances of neofunctionalization than subfunctionalization. Surprisingly, we find that genes that were retained as duplicates after the teleost-specific whole-genome duplication 320 million years ago were not more likely to be retained after the Ss4R, and that the duplicate retention was not influenced to a great extent by the nature of the predicted protein interactions of the gene products. Finally, we demonstrate that the Atlantic salmon assembly can serve as a reference sequence for the study of other salmonids for a range of purposes.publishedVersio

Charakterisierung der PKA Regulation im NF1 Signalweg

7 Zusammenfassung Zusammenfassung Im Rahmen der Diplomarbeit sollten zwei Fragestellungen bearbeitet werden. Zum einen sollte untersucht werden, ob die beiden Kelch/β-Prpopeller Proteine Gβ und GβL mit einer Domäne, die im C-terminalen Bereich des Proteins Neurofibromin lokalisiert ist, interagieren. Zum anderen sollte erforscht werden, welchen Einfluss die Signalwege von p38, Protein Kinase A und Ras, auf die Osteoblastendifferenzierung ausüben, da in Versuchen gezeigt werden konnte, dass diese Signalwege in NF1-defizienten Osteoblasten, die eine Störung der Differenzierung aufweisen, aktiviert waren. Um eine mögliche Protein Interaktion zwischen Neurofibromin und Kelch/ß-Propeller-Proteine zu analysieren, war die Durchführung einer Co-Imunopräzipitation von Fragmenten des Nf1-Gens mit den potentiellen Interaktionspartnern geplant. Allerdings gelang es im Rahmen der Diplomarbeit nicht, das Nf1-Fragment mit der potentiellen Kelch/ß-Propeller Bindedomäne in vitro zu exprimieren. Es wird vermutet, dass dies auf eine posttranskriptionelle Degradation des Fragments zurückzuführen ist. Um den Einfluss der Signalwege von Ras, p38 und PKA auf die Osteoblastendifferenzierung zu analysieren, wurde das retrovirale RCAS-Virus-System verwendet. Mithilfe dieses Systems konnten die entsprechenden Signalwege im primären Chicken-Bonemarrow (Osteoblasten) Zellsystem aktiviert werden. Durch eine Analyse der Mineralisierung der Kulturen und der Expression spezifischer Markergene über quantitative Realtime PCR, konnte ein hemmender Effekt des MKK6/p38-Signalwegs und des PKA Signalweges gefunden werden. Eine Inhibierung des Ras-MAPK Signalwegs auf dem Level von MEK (MAP kinase/ ERK Kinase) durch den Inhibitor PD98059 bewirkte eine deutliche Steigerung der Osteoblastendifferenzierung. Dieser Effekt war so stark, dass er die inhibierenden Effekte eines aktivierten MKK6/p38 und PKA Signalwegs kompensierte. Es scheint, dass MEK eine wichtige regulatorische Funktion bei der Osteoblastendifferenzierung einnimmt. Durch Mikroinjektion von RCAS-Viren (die den PKA Signalweg aktivieren) in Hühner- Extremitäten konnte in vivo ein Block der Mineralisierung und eine deutliche Steigerung der Initialen bei gleichzeitiger Hemmung der terminalen Knorpeldifferenzierung, erreicht werden. Untersuchungen im primären Chicken-Micromas-System konnten zeigen, dass es durch Aktivierung des PKA-Signalweges zu einer Steigerung der initialen und einer Verzögerung/Hemmung der terminalen Knorpeldifferenzierung kommt. Dies kann mit der Aktivierung des Transkriptionsfaktors Sox9 durch PKA in Verbindung gebracht werden

Effects of butyrate feed supplementation on gilthead sea bream (Sparus aurata) growth performance and intestinal health: A transcriptomic approach

Poster presentado en la Aquaculture conference "To the next 40 years of sustainable global aquaculture" celebrada en Gran Canaria del 3 al 7 de noviembre de 2013The aim of the present study was to evaluate the effects of a short fatty acid, the commercial butyrate product (BP-70, ®Norel), on gilthead sea bream performance and intestinal health. Juvenile fish of 25 g initial body weight were distributed in 90-L triplicate tanks/group (15 fish/tank). Fish were fed plant protein-based diets with 20% fish meal and 35% plant oil at the expense of fish oil, and with increasing levels of BP-70 (0%, 0.2%, 0.4%, 0.8%) for 9 weeks. No significant effects of butyrate supplementation were found on growth rates, feed conversion ratio, or retention of N and lipids. No effects were found on hepatosomatic index or viscerosomatic index, but the gut index (fish weight/intestine length) was progressively and significantly increased with butyrate supplementation. Butyrate also increased plasma glucose levels and liver glycogen depots, which highly supports a sparing effect of butyrate on the utilization of glucose as a metabolic fuel. A PCR-array of 90 genes was used to characterize the intestinal gene expression pattern of the two extreme groups (0%, 0.8% diets). Genes were selected as markers of intestine cell proliferation and differentiation, intestinal architecture and permeability, enterocyte mass and epithelia damage, intestinal immune-surveillance and mitochondria activity. The differentially expressed genes of all these categories showed that butyrate supplementation clearly induced a healthy intestine condition. In particular, components of the Hedgehog, bone morphogenic protein and Notch signalling pathways were up-regulated in butyrate treated fish, which would orchestrate a complex regulatory network promoting intestine cell differentiation rather than stem cell proliferation. This agrees with the lowered expression of the proliferating cell nuclear antigen (PCNA), as evidenced by RT-PCR and immunocytochemistry. Butyrate also improved the intestine barrier function, up-regulating the expression of several components of tight junctions (occludin, claudin 12, claudin 15, tight junction protein ZO-1, and coxsackievirus and adenovirus receptor homolog), and altered the expression of nuclear-encoded mitochondrial genes, up regulating the expression of master transcription factors, mitochondrial protein translocases and oxidative enzymes of the tricarboxylic acid cycle, and down-regulated the expression of mitochondrial molecular chaperones of the Hsp 10 family. This expression pattern is indicative of a mitochondrial phenotype with a ¿high power¿ activity and a low risk of oxidative stress. In addition, butyrate supplementation altered the expression of interleukin 7, nucleotide-binding protein oligomerization domain-containing protein 1, vimentin, macrophage mannose receptor 1 and C-C motif chemokine 20, leading to an anti-inflammatory gene expression pattern. Therefore, butyrate supplementation as a whole is a very promising approach to improve the health condition of gilthead sea bream intestine.Peer Reviewe