Anne Marie Bakke

Bio: Anne Marie Bakke is an academic researcher from Norwegian University of Life Sciences. The author has contributed to research in topics: Genetically modified organism & Fish meal. The author has an hindex of 24, co-authored 54 publications receiving 2578 citations.

Prebiotics in aquaculture: a review

Abstract: A prebiotic is a non-digestible food ingredient that beneficially affects the host by selectively stimulating the growth and/or the activity of one or a limited number of bacteria in the colon. Despite the potential benefits to health and performance as noted in various terrestrial animals, the use of prebiotics in the farming of fish and shellfish has been less investigated. The studies of prebiotics in fish and shellfish have investigated the following parameters: effect on growth, feed conversion, gut microbiota, cell damage/morphology, resistance against pathogenic bacteria and innate immune parameters such as alternative complement activity (ACH50), lysozyme activity, natural haemagglutination activity, respiratory burst, superoxide dismutase activity and phagocytic activity. This review discusses the results from these studies and the methods used. If the use of prebiotics leads to health responses becoming more clearly manifested in fish and shellfish, then prebiotics might have the potential to increase the efficiency and sustainability of aquaculture production. However, large gaps of knowledge exist. To fully conclude on the effects of adding prebiotics in fish diets, more research efforts are needed to provide the aquaculture industry, the scientific community, the regulatory bodies and the general public with the necessary information and tools.

Important antinutrients in plant feedstuffs for aquaculture: an update on recent findings regarding responses in salmonids

Abstract: Thisreviewpresentsanoverviewofantinutritivefac-tors (ANFs) relevant for ¢sh nutrition.The sources ofANFs and the possibilities of reducing the impact ofANFs are brie£y mentioned. Proteinase inhibitors,lectins, saponins and oligosaccharides are given amore thorough presentation regarding mechanismsofactionandthestateof knowledgeregardingeiectson gut function in ¢sh and upper safe dietary levels.Thereafter, selected results from recent works ad-dressing the involvement of T cells and proteinase-activated receptors in soybean-induced enteritis aresummarized. Our conclusions are as follows: we areonlybeginning tounderstandeiects of ANFs in ¢sh;strengthening of the knowledge base is urgentlyneeded to understand the eiects and to ¢nd themeans to overcome or modify these eiects; interac-tions between the eiects of ANFs appear to be veryimportant; the microbiota may modify the eiects ofANFs; not only salmonids are aiected; not only soy-beans contain ANFs of biological importance in ¢sh;andwithincreasedknowledge,wecandevelopbetterdiets for optimal nutrition, health and economy inaquaculture.Keywords: ¢sh,antinutrients,digestivephysiology,immunology,guthealthIntroductionNature has equipped many plants with the ability tosynthesize avarietyof chemical substances withtheapparentfunctionofprotectingthemfrombecomingfood for microbes, insects and higher animals. Con-sequently, many of these compounds may exertharmful eiects when ingested by humans and ani-mals. Such substances are often called antinutritivefactors (ANFs), although they may also have bene¢-cial eiects, such as being antioxidative, immunosti-mulatory or prebiotic, depending on the amountingested.Possibleharmfuleiectsincludereducedpa-latability,lesse⁄cientutilizationoffeednutrientsforgrowth,alterednutrientbalancesofthediets,inhibi-tion of growth, intestinal dysfunction, altered gutmicro£ora, immune modulation, goitrogenesis, pan-creatic hypertrophy, hypoglycaemia or liver damage.The species of animal, its age, size, gender, state ofhealth and plane of nutrition and any stress factorsmaymodifytheseresponses.Inhistextbookontoxicconstituentsofplantfoods,Liener (1980) wrote the following:‘What has only re-cently been realized is that althoughthere might notbe an immediate violent reaction to a certain foodcomponentthere might still beaslowcumulativead-verse eiect resulting in overt disease or less thanop-timal health. This poses a great challenge, sinceknowledge of these eiects is gained slowlyand withdi⁄culty, particularly if the causative principles re-main unidenti¢ed’. Liener’s statement is still validand relevant. During the last10^15 years, inclusionofplantfeedstuisin¢shfeedhasincreasedmarkedlyand consequently so has exposure toANFs. Antinu-tritivefactorsarenoveltomostcultivated¢shspecies,particularly carnivorous species. Fish nutritionistsshould keep in mind Liener’s warning that ‘there

A high-resolution map of the gut microbiota in Atlantic salmon (Salmo salar): A basis for comparative gut microbial research.

Abstract: Gut health challenges, possibly related to alterations in gut microbiota, caused by plant ingredients in the diets, cause losses in Atlantic salmon production. To investigate the role of the microbiota for gut function and health, detailed characterization of the gut microbiota is needed. We present the first in-depth characterization of salmon gut microbiota based on high-throughput sequencing of the 16S rRNA gene’s V1-V2 region. Samples were taken from five intestinal compartments: digesta from proximal, mid and distal intestine and of mucosa from mid and distal intestine of 67.3 g salmon kept in seawater (12–14 °C) and fed a commercial diet for 4 weeks. Microbial richness and diversity differed significantly and were higher in the digesta than the mucosa. In mucosa, Proteobacteria dominated the microbiota (90%), whereas in digesta both Proteobacteria (47%) and Firmicutes (38%) showed high abundance. Future studies of diet and environmental impacts on gut microbiota should therefore differentiate between effects on mucosa and digesta in the proximal, mid and the distal intestine. A core microbiota, represented by 22 OTUs, was found in 80% of the samples. The gut microbiota of Atlantic salmon showed similarities with that of mammals.

Feeding, digestion and absorption of nutrients

Abstract: Publisher Summary The main function of the alimentary tract of any animal is the acquisition of food with subsequent assimilation of vital nutrients. The natural diet of fishes varies tremendously between fish species and their natural habitats. This chapter summarizes the current state of knowledge, or lack thereof, highlighting the similarities and differences of fish digestive physiology relative to that of the more well studied mammalian systems. Important references, especially review articles, are discusses in the chapter to aid in finding more detailed information as needed. Feeding strategies and development of digestive processes in fish larvae and juveniles, as well as physiological responses to changes in ingredient composition of formulated feeds for cultured fish species have been reviewed.

Human CD141(+) (BDCA-3)(+) dendritic cells (DCs) represent a unique myeloid DC subset that cross-presents necrotic cell antigens

Abstract: The characterization of human dendritic cell (DC) subsets is essential for the design of new vaccines. We report the first detailed functional analysis of the human CD141(+) DC subset. CD141(+) DCs are found in human lymph nodes, bone marrow, tonsil, and blood, and the latter proved to be the best source of highly purified cells for functional analysis. They are characterized by high expression of toll-like receptor 3, production of IL-12p70 and IFN-beta, and superior capacity to induce T helper 1 cell responses, when compared with the more commonly studied CD1c(+) DC subset. Polyinosine-polycytidylic acid (poly I:C)-activated CD141(+) DCs have a superior capacity to cross-present soluble protein antigen (Ag) to CD8(+) cytotoxic T lymphocytes than poly I:C-activated CD1c(+) DCs. Importantly, CD141(+) DCs, but not CD1c(+) DCs, were endowed with the capacity to cross-present viral Ag after their uptake of necrotic virus-infected cells. These findings establish the CD141(+) DC subset as an important functionally distinct human DC subtype with characteristics similar to those of the mouse CD8 alpha(+) DC subset. The data demonstrate a role for CD141(+) DCs in the induction of cytotoxic T lymphocyte responses and suggest that they may be the most relevant targets for vaccination against cancers, viruses, and other pathogens.

Role of gastrointestinal microbiota in fish

Abstract: The gastrointestinal (GI) tract of an animal consists of a very complex and dynamic microbial ecosystem that is very important from a nutritional, physiological and pathological point of view. A wide range of microbes derived from the surrounding aquatic environment, soil/sediment and feed are found to colonize in the GI tract of fish. Among the microbial groups, bacteria (aerobic, facultative anaerobic and obligate aneraobic forms) are the principal colonizers in the GI tract of fish, and in some fish, yeasts are also reported. The common bacterial colonizers in the GI tract of freshwater and marine fish include Vibrio, Aeromonas, Flavobacterium, Plesiomonas, Pseudomonas, Enterobacteriaceae, Micrococcus, Acinetobacter, Clostridium, Fusarium and Bacteroides, which may vary from species to species as well as environmental conditions. Besides, several unknown bacteria belonging to Mycoplasma, Arthrobacter, Brochothrix, Jeotgailbacillus, Ochrobactrum, Psychrobacter and Sejongia species in the GI tract of different fish species have now been identified successfully using culture-independent techniques. Gnotobiotic and conventional studies indicate the involvement of GI microbiota in fish nutrition, epithelial development, immunity as well as disease outbreak. This review also highlights the need for manipulating the gut microbiota with useful beneficial microbes through probiotic, prebiotic and synbiotic concepts for better fish health management.

A 20-year retrospective review of global aquaculture.

Abstract: The sustainability of aquaculture has been debated intensely since 2000, when a review on the net contribution of aquaculture to world fish supplies was published in Nature. This paper reviews the developments in global aquaculture from 1997 to 2017, incorporating all industry sub-sectors and highlighting the integration of aquaculture in the global food system. Inland aquaculture—especially in Asia—has contributed the most to global production volumes and food security. Major gains have also occurred in aquaculture feed efficiency and fish nutrition, lowering the fish-in–fish-out ratio for all fed species, although the dependence on marine ingredients persists and reliance on terrestrial ingredients has increased. The culture of both molluscs and seaweed is increasingly recognized for its ecosystem services; however, the quantification, valuation, and market development of these services remain rare. The potential for molluscs and seaweed to support global nutritional security is underexploited. Management of pathogens, parasites, and pests remains a sustainability challenge industry-wide, and the effects of climate change on aquaculture remain uncertain and difficult to validate. Pressure on the aquaculture industry to embrace comprehensive sustainability measures during this 20-year period have improved the governance, technology, siting, and management in many cases. The volume of global aquaculture production has tripled since 2000 with positive trends in environmental performance, but the sector faces mounting challenges including pathogen management, pollution, climate change, and increasing dependence on land-based resource systems.

Enzyme‐producing bacteria isolated from fish gut: a review

Abstract: Digestion of food depends on three main factors: (i) the ingested food and the extent to which the food is susceptible to the effects of digestive enzymes, (ii) the activity of the digestive enzymes and (iii) the length of time the food is exposed to the action of the digestive enzymes. Each of these factors is affected by a multitude of secondary factors. The present review highlights the experimental results on the secondary factor, enzymatic activity and possible contribution of the fish gut microbiota in nutrition. It has been suggested that fish gut microbiota might have positive effects to the digestive processes of fish, and these studies have isolated and identified the enzyme-producing microbiota. In addition to Bacillus genera, Enterobacteriaceae and Acinetobacter, Aeromonas, Flavobacterium, Photobacterium, Pseudomonas, Vibrio, Microbacterium, Micrococcus, Staphylococcus, unidentified anaerobes and yeast are also suggested to be possible contributors. However, in contrast to endothermic animals, it is difficult to conclude the exact contribution of the gastrointestinal microbiota because of the complexity and variable ecology of the digestive tract of different fish species, the presence of stomach and pyloric caeca and the relative intestinal length. The present review will critically evaluate the results to establish whether or not intestinal microbiota do contribute to fish nutrition.