This work developed a laboratory prototype methodology for cost-effective, water-sparing drip-irrigation of seaweeds, as a model for larger-scale, on-land commercial units, which we envision as semi-automated, inexpensive polyethylene sheet-covered bow-framed greenhouses with sloping plastic covered floors, water-collecting sumps, and pumped recycling of culture media into overhead low-pressure drip emitters. Water droplets form on the continually wetted interior plastic surfaces of these types of greenhouses scattering incoming solar radiation to illuminate around and within the vertically-stacked culture platforms. Concentrated media formulations applied through foliar application optimize nutrient uptake by the seaweeds to improve growth and protein content of the cultured biomass. An additional attribute is that seaweed growth can be accelerated by addition of anthropogenic CO2-containing industrial flue gases piped into the head-space of the greenhouse to reuse and recycle CO2 into useful algal biomass. This demonstration tested three different drip culture platform designs (horizontal, vertical and slanted) and four increasing fertilizer media concentrations (in seawater) for growth, areal productivity, and thallus protein content of wild-collected Ulva compressa biomass, against fully-submerged controls. Cool White fluorescent lights provided 150–200 μmol photon m-2 s-1 illumination on a 12/12 hr day/night cycle. Interactive effects we tested using a four-level single factorial randomized block framework (p<0.05). Growth rates and biomass of the drip irrigation designs were 3–9% day-1 and 5–18 g m-2 day-1 (d.w.) respectively, whereas the fully-submerged control group grew better at 8–11% per day with of 20–30 g m-2 day-1, indicating further optimization of the drip irrigation methodology is needed to improve growth and biomass production. Results demonstrated that protein content of Ulva biomass grown using the vertically-oriented drip culture platform and 2x fertilizer concentrations (42:16:36 N:P:K) was 27% d.w., approximating the similarly-fertilized control group. The drip methodology was found to significantly improve gas and nutrient mass transfer through the seaweed thalli, and overall, the labor- and-energy-saving methodology would use a calculated 20% of the seawater required for conventional on-land tank-based tumble culture.
Digital library
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FAO fisheries fact sheet on Laminaria japonica (Areschoug, 1851), also called kombu or Japanese kelp.
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Finfish culture is a growing industry, and it causes a nutrient loading problem. To investigate the feasibility of an integrated culture of kelp and salmon, 15-cm long kelp (Laminaria saccharina) was grown in salmon culture effluent. The objectives were to test the effects of flow rate and kelp density on dissolved inorganic nitrogen removal (DIN), and DIN uptake and growth by the kelp. NH+, NO- and DIN (NH + NO ) loadings were in the ranges 6.2-25.4, 12.9-40.0, 19.7-52.7 #mol l- 1, respectively, over the experimental period.
Surplus uptake of nitrogen was not evident, because the C:N ratio (10-11) was constant in all experiments. During light periods, the kelp removed from 170-339, mol 1- h - 1, and approximately 26-40% of the incoming DIN. The DIN uptake rate, based on daylight sampling periods, ranged between 6.1-22.5 mol g- dry mass h- 1. The highest-flow rate, lowest-density tank had the highest DIN uptake rate. Debris from the fish effluent settling on the kelp thalli in the low-flow rate tanks affected uptake. Mean DIN uptake rate based on 3 days of growth for all flow-density combinations ranged between 5.4-8.3 #mol g- 1 dry mass h- . The kelp utilized NH and NO- equally.
The growth ranged between 6.5-9% d- . The biomass production ranged from 1-2 g per sampling period. The highest growth rate and biomass production were achieved by kelp in the highest-flow rate, lowest-density tank. Lower DIN concentrations due to higher DIN removal rates in the other tanks and light limitation due to self-shading in the high-density tanks were probably responsible for the reduced growth rate in these tanks.
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Over the last few years, the focus of researchers have been set on enzyme engineering and enzyme immobili- zation technology using natural polysaccharides as promising and green supporting materials to address the challenges of free enzymes for various applications. Polysaccharides have been extensively implemented as enzyme carriers because they can be easily modified chemically according to the nature of immobilization. This process improves the stability and lifetime of laccase in catalytic reactions. Additionally, the selectivity of the enzymes can be preserved for particular application after immobilization onto polysaccharides. This review paper reveals the significance and potential of natural polysaccharides (including cellulose, chitosan, and algi- nate) and their composites as support materials for the laccases immobilization to expand the modified bio- catalysts for industrial applications. Moreover, the roles of immobilized laccases are discussed from a fundamental point of view to elucidate their catalytic mechanisms as biocatalysts in the detection and degra- dation of environmental contaminants.
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Adhesion of Chlorella vulgaris (chlorophyceae), Nitzschia amphibia (bacillariophceae) and Chroococcus minutus (cyanobacteria) to hydrophobic (perspex, titanium and stainless steel 316-L), hydrophilic (glass) and toxic (copper, aluminium brass and admiralty brass) substrata were studied in the laboratory. The influence ofsurface wettability, surface roughness, pH of the medium, culture age, culture density, cell viability and presence of organic and bacterial films on the adhesion of Nitzschia amphibia was also studied using titanium, stainless steel and glass surfaces. All three organisms attached more on titanium and stainless steel and less on copper and its alloys. The attachment varied significantly with respect to exposure time and different materials. The attachment was higher on rough surfaces when compared to smooth surfaces. Attachment was higher on pH 7 and above. The presence of organic film increased the attachment significantly when compared to control. The number of attached cells was found to be directly proportional to the culture density. Attachment by log phase cells was significantly higher when compared to stationary phase cells. Live cells attached more when compared to heat killed and formalin killed cells. Bacterial films of Pseudomonas putida increased the algal attachment significantly.
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Thallus bits of Gracilaria edulis, G. corticata, G.crassa and Ulva lactuca were maintained in three enriched seawater growth media under laboratory conditions. Weekly observation on growth rate of these algae showed that Walne's medium enhanced Daily Growth Rate (DGR) of Ulva lactuca (54.42 f 3.82 mg/d), Gracilaria corticata (58.71 f 3.35 mg/d) and G. crassa (72.42 f 2.07 mg/d). Gran'laria edulis registered higher growth rate in PES medium (50.42 f 3.82 mg/d) than in Walne's and Gamborg media. However, addition of 2% garden soil extract to Walne's medium promoted the DGR in all the four species considerably (62.28 mg/d for Ulva, 66.71 mg/d for Gracilaria corticata, 77.71 mg/d for G. crassa and 56.29 mg/d for G. edulis). The results are compared with the growth rate of seaweeds achieved elsewhere in in situ sea farming being carried out without addition of any nutrients extraneously.
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Seaweeds, as the name implies covers the macroscopic plant life of the sea except the flowering plants. Most of the seaweeds are attached to rocks and also grow oh other plants as epiphytes. Along the coastline of India, seaweeds are abundant where rocky or coral formations occur. This sort of substratum is found in the states .of Tamil Nadu and Gujsrst and in the vicinity of Bombay, Ratnagiri, Goa, Karwar, Vizhinjam, Varkala, Vishakapatnam and in the Lakshadweep and Andaman-Nicobar Islands. The seaweeds are classified into three important Q'Oups namely Green, Brown and Red seaweeds. Seaweeds contain different vitamins, minerals, trace elements and proteins. Seaweeds are also a rich source of iodine.
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Can rudderfish (Family Kyphosidae–an herbivorous, active-swimming reef-fish) provide a biological model for macroalgae biodigestionas a route to renewable bioenergy?
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I’m really delighted to be here with all of you. It’s my first time attending such a summit. I reallyappreciate and value the opportunityto get to know you better and hear more about yourperspectives, so thanks very much. As Dawn alluded to in her introduction,I’ve had some priorchances to learn a good bit and see the kind of change that’s occurred in fisheries and fisheriesmanagement over the past 25 years. My stint as NOAAChiefScientist gave me a goodopportunity to take a close look at the science underlying this field and the challenges that weface here. And then,several years later, I had my first exposureto the opportunities andchallenges of aquaculture when I headed up the aquaculture panel on the PEW OceansCommission. SoI am delighted to be here today,andI’d like to talk about a couple of things:about building resiliency in our oceans and our fishing communities;aboutbuilding healthy andsustainable fisheries to support societal, economic, and ecological resilience; the steps we’retaking to combat illegal fishing and seafood fraudandlevel the playingfieldfor U.S. fishermen;and the role that aquaculture can play and needs to play in our collective future
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The design of keys for identification of algae is based on the external form with addition of obvious cytological details Form alone can be used for large thalloid algae. Form combined with pigmentation and chromatophore shape can lead to the identification of many algae. It is often necessary to examine the apex of branches to determine the manner of growth.
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