The effect of 2-day heat stress on the lipid composition of bovine milk and serum

Milk and serum were collected from dairy cows before and during a 2-day heat challenge. The concentrations of free short-chain fatty acids (SCFAs), the fatty acid (FA) profile, and the abundance of the major species of phosphatidylcholine (PC), phosphatidylethanolamine (PE), and sphingomyelin (SM) were measured, and samples collected during heat exposure were compared with those collected prior to heat exposure. It was found that a 2-day heat challenge did not alter the global FA composition of milk fat nor the content of the major phospholipids. Although the concentration of SCFAs C3 and C4 and some lysophosphatidylcholine (LPC) species in milk was found to be associated with the forage type, neither of these lipid molecules can be used as an indicator of acute heat stress. While it is a positive finding that short-term heat stress has no detrimental effect on the FA composition or the nutritive quality of milk fat, this study highlights the complexity of validating a milk lipid biomarker for heat stress in dairy cows

Aromatic metabolites from the coelomic fluid of Eisenia earthworm species

Earthworms from the genus Eisenia express coelomic fluid when under severe stress. This coelomic fluid contains a complex mixture of small-molecule metabolites, including aromatic metabolites which are known to be species-specific, yet their actual identities remain unknown. We have aimed to characterize selected high-concentration coelomic fluid metabolites. The major aromatic compound in Eisenia veneta coelomic fluid is the rare metabolite a-nicotinamide riboside; and the major aromatic compound for Eisenia fetida is closely related to the (already characterized) metabolite of Eisenia andrei, which consists of two aromatic quinazoline-2,4-dione ring structures linked by N-acetylspermine. The biological function(s) of these metabolites in earthworms is unknown, but we hypothesize that they represent remnants of larger molecules, possibly bacterial in origin, that are recalcitrant to metabolism by earthworm enzymes. (C) 2016 The Authors. Published by Elsevier Masson SAS

Bovine Milk Triacylglycerol Regioisomer Ratio Shows Remarkable Inter-Breed and Inter-Cow Variation

Regioisomers (or positional isomers) of triacylglycerols (TAGs) of milk are known to show differential outcome in relation to human absorption. Quantitation of TAG regioisomers remains a big challenge due to the lack of facile chromatographic separation technique. The feasibility of using fragment ion intensity ratio to determine the ratio of co-eluting AAB/ABA-type regioisomer pairs was confirmed in this study. The ability of C30 stationary phase in resolving interfering TAG isomers was demonstrated for the first time. This allowed us to reveal the complexity of using fragment ion intensity to quantify 1,2-olein-3-palmitin (OOP), 1,3-olein-2-palmitin (OPO), 1,2-olein-3-stearin (OOS), and 1,3-olein-2-stearin (OSO) regioisomers in milk samples. A novel algorithm was proposed to consider the contribution of OPO/OOP and OSO/OOS double bond (DB)-isomers and to eliminate the interference of isobaric ions from other isomers, an aspect overlooked in previous studies. This liquid chromatography-mass spectrometry method that requires no pre-fractioning and a moderate chromatographic separation time of 36 min is simple and, thus, suitable for screening a large number of samples for genetic analysis of this trait. Preliminary results using a small cohort of animals showed that OPO/OOP ratio differs significantly between Jersey and Holstein cows, and a large variation was also observed across individual Holstein cows

Optimisation of Protein Extraction from Medicinal Cannabis Mature Buds for Bottom-Up Proteomics

Medicinal cannabis is used to relieve the symptoms of certain medical conditions, such as epilepsy. Cannabis is a controlled substance and until recently was illegal in many jurisdictions. Consequently, the study of this plant has been restricted. Proteomics studies on Cannabis sativa reported so far have been primarily based on plant organs and tissues other than buds, such as roots, hypocotyl, leaves, hempseeds and flour. As far as we know, no optimisation of protein extraction from cannabis reproductive tissues has been attempted. Therefore, we set out to assess different protein extraction methods followed by mass spectrometry-based proteomics to recover, separate and identify the proteins of the reproductive organs of medicinal cannabis, apical buds and isolated trichomes. Database search following shotgun proteomics was limited to protein sequences from C. sativa and closely related species available from UniprotKB. Our results demonstrate that a buffer containing the chaotrope reagent guanidine hydrochloride recovers many more proteins than a urea-based buffer. In combination with a precipitation with trichloroacetic acid, such buffer proved optimum to identify proteins using a trypsin digestion followed by nano-liquid chromatography tandem mass spectrometry (nLC-MS/MS) analyses. This is validated by focusing on enzymes involved in the phytocannabinoid pathway

Carp chemical sensing and the potential of natural environmental attractants for control of carp: a review

Environmental context. Carp are responsible for causing significant damage to lakes and rivers resulting in highly turbid water impacting native fish. At present there are no effective ways to manage the damage caused by carp or eradicate them, but the efficiency of carp removal from our waterways can be enhanced by the development of naturally occurring environmental attractants. As part of a broader pest management scheme the implementation of these attractants can significantly enhance the effectiveness of eradication programs and lead to the restoration of our waterways. Abstract. Cyprinus carpio, a species of carp commonly known as European or common carp, are invasive alien species in Australian inland waters and have an extensive impact on biodiversity and the aquatic environment. The control and eradication of carp is a major focus of fisheries services throughout Australia, but at present there is no wholly successful way to limit the damage caused. An integrated pest management scheme (IPM) is the most likely approach to be effective. Such a scheme could employ current tactics such as trapping in combination with new strategies including attractants or deterrents. Among proposed attractants are environmentally derived chemicals. Carp have long been observed to prefer certain habitats and environmental conditions over others, although the reasons for such a preference are not well defined. This article reviews the current scientific literature for chemical reception and attraction in carp with an emphasis on environmentally derived attractants and the potential for use of these chemical cues to enhance IPM strategies with minimal environmental impact

Optimisation of Milk Protein Top-Down Sequencing Using In-Source Collision-Induced Dissociation in the Maxis Quadrupole Time-of-Flight Mass Spectrometer

Top-down sequencing in proteomics has come of age owing to continuous progress in LC-MS. With their high resolution and broad mass range, Quadrupole Time-of-Flight (Q-ToF) hybrid mass spectrometers equipped with electrospray ionisation source and tandem MS capability by collision-induced dissociation (CID) can be employed to analyse intact proteins and retrieve primary sequence information. To our knowledge, top-down proteomics methods with Q-ToF have only been evaluated using samples of relatively low complexity. Furthermore, the in-source CID (IS-CID) capability of Q-ToF instruments has been under-utilised. This study aimed at optimising top-down sequencing of intact milk proteins to achieve the greatest sequence coverage possible from samples of increasing complexity, assessed using nine known proteins. Eleven MS/MS methods varying in their IS-CID and conventional CID parameters were tested on individual and mixed protein standards as well as raw milk samples. Top-down sequencing results from the nine most abundant proteoforms of caseins, alpha-lactalbumin and beta-lactoglubulins were compared. Nine MS/MS methods achieved more than 70% sequence coverage overall to distinguish between allelic proteoforms, varying only by one or two amino acids. The optimal methods utilised IS-CID at low energy. This experiment demonstrates the utility of Q-ToF systems for top-down proteomics and that IS-CID could be more frequently employed

A Simple Method for Simultaneous Quantification of Total Arabinoxylans and Fructans in Wheat Flour

Current methods for measuring fructan and arabinoxylan concentrations in wheat flour are time-consuming, and each type of the polymers requires a separate method. Here, we report the development of a new method that allows simultaneous determination of arabinoxylan and fructan contents in wheat flour. The new method is based on a single hydrolysis procedure for both arabinoxylans and fructans and an optimized separation technique for all monomers released. Owing to the use of milder hydrolysis conditions that afforded higher recovery of pentoses, the level of arabinoxylans in wheat flour determined by this new method is slightly higher than that measured with the widely used hydrolysis protocol. On the basis of the finding that, for a given flour sample, the total fructose concentration after hydrolysis is highly correlated with its total fructan concentration, the fructan content of a wheat flour sample can thus be estimated directly by the total fructose content. By simplifying and combining the two separate methods used for arabonoxylan and fructan analysis, this new method enables the quantification of arabinoxylans and fructans in wheat flour using a single acid hydrolysis step and a single high-performance liquid chromatography run