Seaweed cultivation is a high growth industry that is primarily targeted at human food and hydrocolloid markets. However, seaweed biomass also offers a feedstock for the production of nutrient-rich biochar for soil amelioration. We provide the first data of biochar yield and characteristics from intensively cultivated seaweeds (Saccharina, Undaria and Sargassum – brown seaweeds, and Gracilaria, Kappaphycus and Eucheuma – red seaweeds). While there is some variability in biochar properties as a function of the origin of seaweed, there are several defining and consistent characteristics of seaweed biochar, in particular a relatively low C content and surface area but high yield, essential trace elements (N, P and K) and exchangeable cations (particularly K). The pH of seaweed biochar ranges from neutral (7) to alkaline (11), allowing for broad-spectrum applications in diverse soil types. We find that seaweed biochar is a unique material for soil amelioration that is consistently different to biochar derived from ligno-cellulosic feedstock. Blending of seaweed and ligno-cellulosic biochar could provide a soil ameliorant that combines a high fixed C content with a mineral-rich substrate to enhance crop productivity.
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Variations in protein, lipid, carbohydrate and astaxanthin content of Enteromorpha intestinalis, Ulva lactuca and Catenella repens were documented over a 10 months period from September 2007 to June 2008. The macroalgal species were collected from six sampling stations of Indian Sundarbans, a Gangetic delta at the apex of Bay of Bengal. On dry weight basis, the protein content varied from 4.15±0.02% (in Catenella repens) at Lothian to 14.19±0.09% (in Catenella repens) at Frasergaunge. The lipid content was low and varied from 0.07±0.02% (in Enteromorpha intestinalis) at Lothian to 1.06± 0.12% (in Ulva lactuca) at Gosaba. The level of carbohydrate was very high compared to that of lipid and protein and varied from 21.65± 0.76% (in Catenella repens) at Gosaba to 57.03± 1.63% (in Enteromorpha intestinalis) at Lothian. Astaxanthin values ranged from 97.73± 0.32 ppm (in Catenella repens) at Gosaba to 186.11± 2.72 ppm (in Enteromorpha intestinalis) at Frasergaunge. The values varied over a narrow range in the remaining stations. The results of biochemical composition of macroalgae seem to be strongly influenced by ambient hydrological parameters (surface water salinity, temperature and nitrate content) in the present geographical locale. INTRODUCTION Far East, where they are used in the food industry [7].
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Studies were made on protein, carbohydrate and lipid from 28 marine algae from Lakshadweep Islands. The protein content ranged from 0.1 to 18.9% in green algae, 4.6 to 12.2% brown algae and 2.7 to 13.1% in red algae. The carbohydrate content was from 0.5 to 15.846, 1.5 to 13.0% and 2.0 to 29.4% in gMn, brown and red algae respectively. The lipid content varied from 2.6 to 13.8% in green algae, 2.2 to 8.3% in brown algae and 3.1 to 8.3% in red algae
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The present paper deals with some important biochemical components such at proteins, carbohydrates and lipids of 33 marina algae, growing abundantly on the coast of Ramanathapuram District. The results indicated that the green algae (Chlorophyceae) has the maximum of protein content ranging from 6 to 25.8%, next in order comes the brown algae (Phaeophyceae) with13 to 16.6% followed by red algae (Rhodophyceae) with 1.5 to 8.8%. The range of carbohydrate content was from 0.3 to 11.6% in green algae, 3.3 to 24.9% in brown algae and 1.8 to 57.0% in red algae. The lipid content ranged from 0.6 to 8.6% in green algae, 0.6 to 3.7% in brown algae and 0.4 to 6.1% in red algae. The results of the study give an Insight into the biochemical content of the algal species studied could be used to decide their suitability for the formulation of feed to fishes in aquaculture and to other animals.
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The recent and unexpected finding that methanogenic bacteria occupy an isolated biochemical island in the sea of procaryotes has added a touch of excitement to the study of these organisms1. This island is defined by such diverse biochemical qualities as: a very restricted range of oxidizable substrates coupled to the biosynthesis of methane; synthesis of an unusual range of cell-wall components; synthesis of biphytanyl glycerol ethers as well as high amounts of squalene; synthesis of unusual coenzymes and growth factors; synthesis of rRNA that is distantly related to that of typical bacteria; possession of a genome size (DNA) approaching 1/3 that of E. coli.
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The present investigation was targeted on anaerobic digestion of Chroococcus sp. and utilization of resul- tant ‘‘Liquid Digestate’’ for its further biomass production. The algal biomass has biomethane potential of 317.31 ± 1.9 mL CH4 g1 VSfed. Regular process monitoring revealed that process was stable throughout the experiments. The ‘‘Liquid Digestate’’ was explored as nutrient supplement for further algal growth. Diluted ‘‘Liquid Digestate’’ (30% concentration) was found optimal for algal growth (0.79 ± 0.064 g L1). Simultaneously, 69.99–89.31% removal in nutrient and sCOD was also recorded with algal growth. Inter- estingly, higher growth was observed when rural sector wastewater (1.29 ± 0.067 g L1) and BG11 broth (1.42 ± 0.102 g L1) was used for diluting the ‘‘Liquid Digestate’’. The current findings have practically proven the feasibility of hypothesized ‘‘closed loop process’’.
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A PDF Power Point slide on "Bioconversion of Biofuel Resides into Aquatic Feed".
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Energy security, high atmospheric greenhouse gas levels, and issues associated with fossil fuel extraction are among the incentives for developing alternative and renewable energy resources. Biofuels, produced from a wide range of feedstocks, have the potential to reduce greenhouse gas emissions. In particular, the use of microalgae as a feedstock has received a high level of interest in recent years.
Microalgal biofuels are promising replacement for fossil fuels and have the potential to displace petroleum-based fuels while decrease greenhouse gas emissions. The primary focus of research and development toward algal biofuels has been on the production of biodiesel or renewable diesel from the lipid fraction, with use of the non-lipid biomass fraction for production of biogas, electricity, animal feed, or fertilizer.
Since the non-lipid fraction, consisting of mainly carbohydrates and proteins, comprises approximately half of the algal biomass, our approach is biological conversion of the lipid-extracted algal biomass (LEAB) into fuels. We used LEAB from Nannochloropsis salina, and ethanol was the model product. The first step in conversion of LEAB to ethanol was deconstruction of the cell wall into fermentable substrates by using different acids or enzymes. Sugar release yields and rates were compared for different treatments. One-step sulfuric acid hydrolysis had the highest yield of released sugars, while the one-step hydrochloric acid treatment had the highest sugar release rate. Enzymatic hydrolysis produced acceptable sugar release rates and yields but enzymes designed for algal biomass deconstruction are still needed. Proteins were deconstructed using a commercially available protease.
The hydrolysate, containing the released sugars, peptides, and amino acids, was used as a fermentation medium with no added nutrients. Three ethanologenic microorganisms were used for fermentation: two strains of Saccharomyces cerevisiae (JAY270 and ATCC 26603) and Zymomonas mobilis ATCC 10988. Ethanol yields and productivities were compared. Among the studied microorganisms, JAY270 had the highest ethanol yield while Z. mobilis had the lowest yield for most of the studied conditions. A protease treatment improved the biomass and ethanol yields of JAY270 by providing more carbon and nitrogen.
To increase ethanol productivity, a continuous fermentation approach was adapted. Continuous stirred tank reactors have increased productivity over batch systems due to lower idle time. The downtime associated with batch fermentation is the time it takes for empting, cleaning, and filling the reactor. Productivity in the continuous fermentation was limited by the growth characteristics of the microorganism since at high flow rates, with washout occurring below a critical residence time. To overcome the washout problem, the use of an immobilized cell reactor was explored. The performance (ethanol productivity) of free and immobilized cells was compared using an enzymatic hydrolysate of LEAB. Higher ethanol productivities were observed for the continuous immobilized cell reactor compared to the stirred tank reactor.
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Through the years, several strains and color morphotypes of Kappaphycus and Eucheuma have emerged in cultivation areas as a result of environmental and anthropogenic factors. This led to confusion in nomenclature of these seaweeds. However, the advent of molecular technology has brought notable changes to seaweed research over the past two decades. New molecular techniques have proved useful, particularly in the molecular identification and cataloging of economically important carrageenophytes, i.e. Kappaphycus and
Eucheuma which were commercially introduced into many countries worldwide. The following chapter discusses the application and findings of molecular studies within the context of these red seaweeds, along with potential areas for future research.
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The Green Revolution boosted agricultural production approximately 2.5 times and was associated with an approximately 40% price reduction in the cost of food (MA, 2005). Following on the euphoria of this success there has been increasing pressure to diversify production and to improve the planet’s environment (Hubert et al., 2010). Successful realization of this pressure will require better soil management. However, current conditions are very different from what they were 50 years ago. The success of the Green Revolution came at the expense of the natural capital, such that 18 of the 24 currently acknowledged ecosystem services have been impaired. Although soils have aided climate regulation by sequestering an estimated 2 Gt carbon (C) per annum from fossil fuel burning, they have lost part of their capacity to regulate hydrological fluxes and nutrient cycles and therefore to support plant production. The soils of the earth are now being asked to produce 70% more food over the next 35 years, while also producing biofuels, regulating climate through further C sequestration, and helping to conserve biodiversity. However, the other side of this coin is the declining amount of land remaining available for conversion to agroecosystems and the increased cost of energy, which has led to a substantial increase in the price of fertilizers. Further, world sources of phosphorus (P) are being rapidly depleted and the toxic effects of pesticides are now forcing the replacement of these former pillars of intensive agriculture with new technical options. Agriculture now needs to sustain high levels of production while preserving or restoring the natural capital of the soil. Maintenance of an appropriate level of soil biodiversity is critical to achieving this goal, but in order to protect the soil resource and optimize its long-term use, new land use practices are needed to be developed, based on much greater understanding of the factors controlling its functioning. This article summarizes the current knowledge of the composition and taxonomic richness of the soil biota. It then examines the participation of the soil biota in the major soil functions and discusses ways to reconcile the conservation and/or improvement of this natural capital with the production of critical ecosystem goods and services.
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