In fits and starts, Maine's seaweed industry is growing. Entrepreneurs are trying to create new markets for seaweed-based products, like fertilizers, pet medicines, condiments, even granola. But as harvests rise off Maine's coast, so do some concerns that the resource needs protection.
Seaweeds are a potential source of bioactive compounds that are useful for biotechnological applications and can be employed in different industrial areas in order to replace synthetic compounds with components of natural origin. Diverse studies demonstrate that there is a solid ground for the exploitation of seaweed bioactive compounds in order to prevent illness and to ensure a better and healthier lifestyle. Among the bioactive algal molecules, phenolic compounds are produced as secondary metabolites with beneficial effects on plants, and also on human beings and animals, due to their inherent bioactive properties, which exert antioxidant, antiviral, and antimicrobial activities. The use of phenolic compounds in pharmaceutical, nutraceutical, cosmetics, and food industries may provide outcomes that could enhance human health. Through the production of healthy foods and natural drugs, bioactive compounds from seaweeds can help with the treatment of human diseases. This review aims to highlight the importance of phenolic compounds from seaweeds, the scope of their production in nature and the impact that these compounds can have on human and animal health through nutraceutical and pharmaceutical products.
An excess of organic waste, containing up to 60% cellulose and hemicellulose is prodqced worldwide. The conversion of this cellulosic material to ethanol is discussed: The two-step process consisting of a hydrolysis step to glucose and the subsequent fermentation by yeasts; and the one-step process, a fermentation of the cellulose by the anaerobic thermophile Clostridium thermocellum, or by a thermophilic, anaerobic, defined mixed culture. The use of the latter seems to be very feasible. To achieve an economic process, it is suggested to combine this approach with a thermophilic fermentation of the effluent and/or stillage obtained to produce methane.
A growth trial and a digestibility trial were conducted to evaluate seaweed Ulva sp. as a substitution for fish meal (FM) in commercial-type feed formulation for Pacific white shrimp, Litopenaeus vannamei. Towards this goal, the 6-week growth trial utilized increasing levels (0, 6.35, 12.7, 19.05, and 25.4%) of the first batch of Ulva meal (UM1) to replace up to 8% FM in a plant-based feed formulation. At the end of the growth trial, shrimp offered diets containing 12.7, 19.05, and 25.4% UM1 exhibited significantly reduced weight gain. Apparent net protein retention (ANPR) was significantly decreased, while feed conversion ratio (FCR) was significantly increased when shrimps were fed with diets containing 19.05 and 25.4% UM1. Crude lipid content of whole shrimp samples were significantly decreased when UM1 was supplemented in the diets. Apparent digestibility coefficients of dry matter, energy, protein, and amino acids of two batches of Ulva meal (UM1 and UM2) were determined using chromic oxide as an inert maker and the 70:30 replacement technique. Energy and protein digestibility of UM1 and UM2 were significantly lower than FM and soybean meal (SBM) which were run at the same time. As a result of relatively low protein availability, individual amino acids digestibility of UM1 and UM2 are also significantly lower than those of FM and SBM. Results of the present study indicate that UM1 can be included in the shrimp diet up to 6.35% to replace 2% fish meal without resulting in growth depression. The low nutrients availability and high mineral contents of Ulva meal may explain a portion of the observed reduction in shrimp growth.
It is important to accurately evaluate the wellbeing or nutritional condition of organisms when monitoring the wild stock conditions and improvement in aquaculture techniques; however, reliable nutritional condition indexes have not been established for sea cucumbers. In this study, the effects of starvation on condition factor (body weight / body volume), coelomic fluid constituent (protein, carbohydrate and cholesterol) concentrations and coelomic fluid density were analysed in an attempt to establish a method to determine nutritional condition in juvenile sandfish (Holothuria scabra). Body length, breadth and weight of juveniles produced at the sea cucumber hatchery of the Aquaculture Department, Southeast Asian Fisheries Development Center, were measured after anaesthetisation with 2% menthol-ethanol. Coelomic fluid protein level was analysed by the bicinchoninic acid method. Carbohydrate level was analysed by the phenol – sulfuric acid method. Cholesterol level was analysed by the Zak method. Coelomic fluid volume and coelomic fluid weight were measured. Starvation caused a concomitant decrease in body length, breadth and weight, resulting in no net change in the condition factor. This result indicated that condition factor cannot be used as a nutritional condition index. Coelomic fluid constituent level could be measured with a small volume of sample (i.e. 10–20 µL). Although no clear pattern was observed in coelomic fluid protein and cholesterol levels during the starvation trial, carbohydrate level increased, as did coelomic fluid density. These results suggest that coelomic fluid density and carbohydrate level may be used as indexes for nutritional condition of sandfish without sacrificing the animal.
Five bacterial strains were isolated for primary screening to test the phosphate solubilizing activity fromseaweed fed earthworm gut and seaweed vermicompost. The selected three bacteria were tested for phosphatesolubilizing activity in Pikovskaya’s broth amendedwith 250mg of TCP. Among the bacteria, maximum phosphatesolubilization was observed in B. licheniformis i. e., 795.3 ±10.5μg/ml. 16S rRNA sequence of most efficient bacteria,Bacillus licheniformis strain APSAC 04 was deposited inthe NCBI Gen bank with the following accession numberKY886136 for further retrieval and comparison.
In this study, Saccharina japonica was treated with pressurized hot water extraction (PHWE) at a temperature of 180 °C–420 °C and pressure between 13 bar and 520 bar. The obtained hydrolysate was investigated for their yield, total organic carbon (TOC), pH, Maillard reaction products, viscosity, color, and amino acid, mineral, and monosaccharide contents. The extraction yield increased with an increase in temperature and varied from 72.21% to 98.91%. TOC, pH, and potassium and sodium content increased, whereas viscosity decreased, with an increase in temperature. Essential amino acids such as valine and lysine and non-essential amino acids such as aspartic acid, glutamic acid, glycine, and tyrosine recovered well at low temperature. The content of heavy metals such as arsenic, cadmium, mercury, and lead was very low in the obtained hydrolysate. The maximum amount of total amino acids was recovered at 180 °C/13 bar (761.95 ± 14.54 mg/g). The level of main monosaccharides such as glucose (6.70 g/L), fructose (8.40 g/L), and mannitol (17.50 g/L) was found to be very high at 180 °C/13 bar. The results indicated that the pressurized hot water extract of S. japonica has good potential for use in the fermentation industry and can be used as human food.
This document contains the proceedings of the technical workshop entitled “Expanding mariculture: technical, environmental, spatial and governance challenges”, held from 22 to 25 March 2010, in Orbetello, Italy, and organized by the Aquaculture Branch of the Fisheries and Aquaculture Department of the Food and Agriculture Organization of the United Nations (FAO). The objective of this workshop was to discuss the growing need to increasingly transfer land-based and coastal aquaculture production systems farther off the coast and provide recommendations for action to FAO, governments and the private sector. The workshop experts proposed general “operational criteria” for defining mariculture activities in three broad categories: (i) coastal mariculture, (ii) off the coast mariculture and (iii) offshore mariculture. Offshore mariculture is likely to offer significant opportunities for food production and development to many coastal countries, especially in regions where the availability of land, nearshore space and freshwater are limited resources. Mariculture is also recognized as a relevant producer of the protein that the global population will need in the coming decades. It is likely that species with the highest production today, such as salmon, will initially drive the development of offshore mariculture. Nevertheless, the workshop agreed that additional efforts are necessary to define optimal species and improve efforts in the development and transfer of technologies that can facilitate offshore mariculture development. The workshop discussions and reviews indicate large potential for the development of offshore mariculture although more detailed assessments are needed to determine the regions and countries that are most promising for development. It is also recommended that efforts be increased to farm lower trophic levels species and optimize feeds and feeding in order to minimize ecosystems impacts and ensure long-term sustainability. Similarly, risk assessments and/or environmental impact assessment and monitoring must always be in place before establishing offshore farms, and permanent environmental monitoring must be ensured. All coastal nations should be prepared to engage actively in developing the technological, legal and financial frameworks needed to support the future development of offshore mariculture to meet global food needs. The workshop report highlights the major opportunities and challenges for a sustainable mariculture industry to grow and further expand off the coast. In particular, the workshop recommended that FAO should provide a forum through which the potential importance of the sea in future food production can be communicated to the public and specific groups of stakeholders and to support its Members and industry in the development needed to expand mariculture to offshore locations. The proceedings include the workshop report and an the accompanying CD–ROM containing six reviews covering technical, environmental, economic and marketing, policy and governance issues, and two case studies on highfin amberjack (Seriola rivoliana) offshore farming in Hawaii (the United States of America) and one on salmon farming in Chile.
Experimental culture of Gracilaria was done in the Kovalam Backwaters at the Mariculture Centre, Muttukadu, Tamil Nadu. The study, conducted over two years, revealed that the period June to March was condusive to growth. The rate of growth was better in the open, unenclosed area than in ponds. Growth was best during the period June to September. The potential yield in the different growing seasons has been estimated for the open area as well as ponds. The relation between the growth of seaweeds and some environmental conditions in the farm is discussed. A strategy is suggested for the continuous culture and domestication of this species in the area.
Marine Agronomy Group, CAFNRM, UH-Hilo
200 W. Kawili st., HI 96720, USA
Contact: Marine.Agronomy.Group@gmail.com
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