scholarly journals Toward environmentally sustainable aquafeeds

Elem Sci Anth ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Madilyn M. Gamble ◽  
Pallab K. Sarker ◽  
Anne R. Kapuscinski ◽  
Suzanne Kelson ◽  
Devin S. Fitzgerald ◽  
...  

Aquaculture is the fastest growing food production sector and currently supplies almost 50% of fish for human consumption worldwide. There are significant barriers to the continued growth of industrial aquaculture, including high production costs and harmful environmental impacts associated with the production of aquaculture feed. Most commercial aquaculture feeds are based on fish meal, fish oil, and terrestrial plant ingredients, which contain indigestible forms of phosphorus. Phosphorus loading from aquaculture effluent can lead to eutrophication in aquatic ecosystems. Formulating fish feeds using ingredients that contain highly bioavailable forms of phosphorus in nutritionally appropriate quantities will reduce phosphorus loading. Using both in vivo and in vitro experiments, we examined the digestibility of phosphorus in three experimental tilapia feeds supplemented with two freshwater microalgae (Spirulina sp., Chlorella sp.) and one marine microalga, Schizochytrium sp., relative to a reference diet containing fish meal and fish oil. We also calculated a phosphorus budget to quantify metabolic phosphorus waste outputs. The marine Schizochytrium-supplemented diet had the highest phosphorus digestibility and the lowest solid phosphorus discharge compared to the reference diet and the other experimental diets. The Schizochytrium ingredient also had the highest phosphorus digestibility among the three microalgae tested in vitro experiments. These results suggest that Schizochytrium sp. is a highly digestible source of phosphorus and findings on metabolic phosphorus waste outputs have implications for the formulation of sustainable diets for tilapia. Further research must examine the economic feasibility and environmental impacts of producing Schizochytrium sp. as an aquafeed ingredient.

1980 ◽  
Vol 3 ◽  
pp. 85-90 ◽  
Author(s):  
I. H. Pike ◽  
I. N. Tatterson

Most of the by-products from fish go into the production of fish meal and fish oil, the latter going directly to the human food chain, and therefore do not really come under the heading of industrial by-products and waste per se. Broadly speaking, fish meal made from fish offal is a by-product which otherwise would have been wasted. This paper discusses the quantities involved and the nutritional properties offish meal, and in addition, the contribution to fish meal and fish oil made from species which are not suitable for human consumption (e.g. sandeels) or where the quantities caught exceed the demand for human consumption (e.g. sprats).Any method of utilizing fish by-products for animal feeding should minimize chemical changes in the product to avoid reduction in the nutrients which are present at the time of catching. In some respects chemical changes in fish by-products are brought about in a similar way to those in grass, cut for preservation. The fish material has a high water content, around 75%, and from the time of catching is subject to chemical changes by enzymes in the fish and also by bacterial action. Fish, however, differs from grass in that it contains oil and virtually no carbohydrates. The demersal, or lean fish, for example, cod, haddock, plaice, saithe, etc., contain high levels of oil in the liver which are removed for separate processing, but little in the flesh and in the offal produced. The ‘industrial’ fish caught are mainly pelagic species with high levels of oil in the flesh.


2021 ◽  
pp. 0734242X2199680
Author(s):  
Luis U Medina Uzcátegui ◽  
Karina Vergara ◽  
Gabriela Martínez Bordes

The industrial mussel processing generates significant quantities of waste. Nearly 30% of one metric tonne of processed mussel is finally destined for human consumption. Regardless of the mussel commodities, an important quantity of waste is concentrated at several sub-processes, such as input reception, washing and declumping shells, and mussel meat extraction stages, or by means of the rejection of mussels only due to a size characteristic criterion established by the target market. Despite the main segregated waste comprising shells, byssus threads, residual meat and wastewater, a heterogeneous composition must be taken into account, since much of the solid waste is commonly gathered and compacted for landfill transportation purposes. This paper reviews the sustainable management strategies for mussel by-products, addressing their limitations for an industrial implementation to obtain value-added products. It is concluded that, although there is a well-known diversity of waste sustainable management alternatives, several proposed products (e.g., collagen, bio-adhesives, biopolymer, and adsorbent for pollutants) still remain in a potential framework, circumscribed into laboratory results, subject to an optimization process, to a validation by industrial pre-scale trials, or even limited by the associated production costs. Future researches should focus on reducing the uncertainties linked with their technical–economic feasibility for an industrial scale development.


2018 ◽  
Vol 22 (1) ◽  
pp. 149-164 ◽  
Author(s):  
Kriss Spalvins ◽  
Dagnija Blumberga

Abstract Aquaculture is currently the fastest growing food-producing sector in the world. The growth of this industry has been rapid for the last 25 years, however, aquaculture still relies heavily on feed input from wild capture fisheries. Landings in wild capture fisheries have been stagnant for the last two decades; therefore, new alternatives for conventional fish meal and fish oil need to be found. In this review, various alternatives are described and their advantages and disadvantages are evaluated. Single cell oils (SCO) and single cell proteins (SCP) produced by microorganisms are recognized as the alternative with the most potential for replacing fish meal and fish oil in aquacultures. However, production costs of SCOs and SCPsare still higher than production costs of Omega-3 rich oils from other sources (wild capture, plant derived oils and genetically modified plants); therefore, currently used substrates need to be replaced with cheaper agriculture and industrial biomass residues applicable for microbial fermentation. In order to evaluate various biodegradable residues and find the most suitable ones for SCO and SCP production, methods analysing resource availability are reviewed.


Author(s):  
J. Metuzals

It has been demonstrated that the neurofibrillary tangles in biopsies of Alzheimer patients, composed of typical paired helical filaments (PHF), consist also of typical neurofilaments (NF) and 15nm wide filaments. Close structural relationships, and even continuity between NF and PHF, have been observed. In this paper, such relationships are investigated from the standpoint that the PHF are formed through posttranslational modifications of NF. To investigate the validity of the posttranslational modification hypothesis of PHF formation, we have identified in thin sections from frontal lobe biopsies of Alzheimer patients all existing conformations of NF and PHF and ordered these conformations in a hypothetical sequence. However, only experiments with animal model preparations will prove or disprove the validity of the interpretations of static structural observations made on patients. For this purpose, the results of in vitro experiments with the squid giant axon preparations are compared with those obtained from human patients. This approach is essential in discovering etiological factors of Alzheimer's disease and its early diagnosis.


Author(s):  
Kanchan P Upadhye ◽  
Divya Senpal ◽  
Minakshee Nimbalwar ◽  
Gouri Dixit

In the present study microemulsion based intranasal gel of rizatriptan using fish oil was prepared for treatment and management of migraine to sustain the drug release and improve the drug residence time in nasal cavity. Fish oil is reported to have antimigraine activity hence it has been used in the present formulation along with cremophore EL as surfactant and Transcutol P as co-surfactant. The pseudoternary phase diagram plotted with these components shown the microemulsion existence region in ratio of (1:9-9:1) surfactant and co-surfactant. The optimized micro-emulsion contained fish oil (45.29%), cremophore E/transcutol P (2:1) and was characterized for pH (6.3±0.02), viscosity (114 ± 3.00cp), % transmittance (99.5 ± 1.01), refractive index (1.335±0.01),). The prepared microemulsion gels were optimized and characterized for in-vitro studies, pH, drug content, rheological studies and stability study. The release of rizatriptan from micro-emulsion gel prepared from carbopol 934 (98.01%) was found to be higher and prolonged than plain gel. Thus, microemulsion based gel was able to prolong drug releaseand improve drug residence time in the nasal cavity. 


2020 ◽  
Vol 16 (8) ◽  
pp. 1227-1244
Author(s):  
Dharmendra Kumar ◽  
Pramod K. Sharma

Background:: Opuntia species, locally known as prickly pear was used for various purposes as food, medicine, beverage, source of dye and animal food. Many studies have revealed its pharmacology activity from time to time. This review is a collection of chemistry, pharmacognosy, pharmacology and bioapplications of the cactus family. Methods: Many sources were used to collect information about Opuntia species such as Pub med, Google scholar, Agris, science direct, Embase, Merk index, Wiley online library, books and other reliable sources. This review contains studies from 1812 to 2019. Results: The plants from the cactus family offer various pharmacological active compounds including phenolic compounds, carotenoids, betalains, vitamins, steroids, sugar, amino acids, minerals and fibers. These bioactive compounds serve various pharmacological activities such as anticancer, antiviral, anti-diabetic, Neuroprotective, anti-inflammatory, antioxidant, Hepatoprotective, antibacterial, antiulcer and alcohol hangover. According to various studies, Opuntia species offer many bioapplications such as fodder for animal, soil erosion, prevention, human consumption and waste water decontamination. Finally, different parts of plants are used in various formulations that offer many biotechnology applications. Conclusion: Different parts of Opuntia plant (fruits, seeds, flowers and cladodes) are used in various health problems which include wound healing, anti-inflammatory and urinary tract infection from ancient times. Nowadays, researches have extended several pharmacological and therapeutic uses of Opuntia species as discussed in this review. Many in-vitro and in-vivo models are also discussed in this review as the proofs of research findings. Various research gaps have been observed in current studies that require attention in the future.


Chemistry ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 238-255
Author(s):  
Esther M. Sánchez-Carnerero ◽  
Marina Russo ◽  
Andreas Jakob ◽  
Lucie Muchová ◽  
Libor Vítek ◽  
...  

Carbon monoxide (CO) is an endogenously produced signaling molecule involved in the control of a vast array of physiological processes. One of the strategies to administer therapeutic amounts of CO is the precise spatial and temporal control over its release from photoactivatable CO-releasing molecules (photoCORMs). Here we present the synthesis and photophysical and photochemical properties of a small library of meso-carboxy BODIPY derivatives bearing different substituents at positions 2 and 6. We show that the nature of substituents has a major impact on both their photophysics and the efficiency of CO photorelease. CO was found to be efficiently released from π-extended 2,6-arylethynyl BODIPY derivatives possessing absorption spectra shifted to a more biologically desirable wavelength range. Selected photoCORMs were subjected to in vitro experiments that did not reveal any serious toxic effects, suggesting their potential for further biological research.


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