The isolation and identification of new microalgal strains producing oil and carotenoid simultaneously with biofuel potential

Taxonomy and phylogeny of twenty two microalgal isolates were examined using both universal and newly designed molecular primers. Among the isolates, Scenedesmus bijugus, Coelastrella sp., Auxenochlorella protothecoides, and Chlorella sp. were particularly promising in terms of producing lipids as measured by fatty acid methyl esters (FAME) analysis and significant concentration of carotenoids. A comparative experiment showed that S. bijugus and Chlorella sp. were the most promising candidates (L(-)(1)d(-)(1), with biomass) 174.77±6.75, 169.81±5.22mg, lipids 40.14±3.31, 39.72±3.89mg, lutein 0.47, 0.36mg, and astaxanthin 0.27, 0.18mg respectively. The fatty acids produced by these microalgal isolates were mainly palmitic, stearic, oleic, linoleic, and linolenic acid. The freshwater microalgal isolate S. bijugus be the most suitable isolate for producing biodiesel and carotenoids, due to high productivity of biomass, lipids, metabolites, and its suitable fatty acid profile.

Estimates of Heterozostera tasmanica, Zostera muelleri and Ruppia megacarpa distribution and biomass in the Hopkins Estuary, western Victoria, by GIS

Knowledge of the spatial arrangement of the seagrass distribution and biomass within the Hopkins Estuary is an essential step towards gaining an understanding of the functioning of the estuarine ecosystem. This study marks the first attempt to map seagrass distribution and model seagrass biomass and epiphyte biomass along depth gradients by the use of global positioning system (GPS) and geographical information system (GIS) technologies in the estuary. For mapping seagrass in small estuaries, ground-surveying the entire system is feasible. Three species of seagrasses, Heterozostera tasmanica (Martens ex Aschers), Zostera muelleri (Irmisch ex Aschers) and Ruppia megacarpa (Mason), were identified in the Hopkins Estuary. All beds investigated contained a mixed species relationship. Three harvest techniques were trialed in a pilot study, with the 25 × 25-cm quadrat statistically most appropriate. Biomass of seagrasses and epiphytes was found to vary significantly with depth, but not between sites. The average estimate of biomass for total seagrasses and their epiphytes in the estuary in January 2000 was 222.7 g m^–2 (dry weight). Of the total biomass, 50.6% or 112.7 g m^–2 (dry weight) was contributed by seagrasses and 49.4% of the biomass (110.0 g m^–2) were epiphytes. Of the 50.6% of the total biomass represented by seagrasses, 39.3% (87.5 g m^–2) were leaves and 11.3% (25.2 g m^–2) were rhizomes. The total area of seagrasses present in the Hopkins Estuary was estimated to be 0.4 ± 0.005 km², with the total area of the estuary estimated to be 1.6 ± 0.02 km² (25% cover). The total standing crop of seagrasses and epiphytes in the Hopkins Estuary in January 2000 was estimated to be 102.3 ± 57 t in dry weight, 56% (56.9 ± 17 t, dry weight) seagrasses and 44% (45.4 ± 19 t, dry weight) epiphytes. Of the seagrass biomass, 39% (39.7 ± 13 t, dry weight) was contributed by leaves and 17% (17.3 ± 7 t, dry weight) by rhizomes.

Biomass and energy transfer to baleen whales in the South Atlantic sector of the Southern Ocean

Baleen whales are an important group of predators on Antarctic krill in the Southern Ocean. During the CCAMLR 2000 Survey to estimate the biomass and distribution of Antarctic krill, International Whaling Commission observers carried out a visual line transect survey to estimate the number of baleen whales occurring in the survey area. This paper reviews techniques used to estimate krill consumption by baleen whales and in combination with estimates of whale abundance estimates of krill consumption are generated for the South Atlantic sector of the Southern Ocean. This survey estimates that the present populations of whales feeding in this region are likely to consume approximately 1.6 million tonnes, but possibly up to as much as 2.7 million tonnes of krill within the summer season. Although this only represents 4–6% of the estimated krill biomass in the region (and probably less than this percentage of the total annual krill production), the depleted numbers of baleen whales resulting from past or current whaling activities should be taken into account when setting quotas for the commercial exploitation of krill if there is to be a recovery to pre-exploitation biomass levels of baleen whales.

Optimization of fatty acid determination in selected fish and microalgal oils

The use of ten fatty acid methyl ester reference standards coupled with a detailed quantification method was shown to significantly optimize the fatty acid determination of selected fish and microalgal oils when compared to methods that use only one reference standard (C19:0 or C23:0) as a relative response factor. When using the mixture of ten reference standards after transesterifying oils with NaOH/BF3, determination of total fatty acids, eicosapentaenoic acid and docosahexaenoic acid improved by an average of 7.3, 11.5 and 8.4%, respectively. Furthermore, improvements of 13.9, 18.9 and 6.8% of total fatty acids, EPA and DHA, respectively, were obtained when using the mixture of reference standards for fatty acid determination after directly extracting and transesterifying oil contained in microalgal cells with a mixture of methanol, HCl and chloroform. Fatty acid methyl ester standards dissolved in isooctane showed <5% variability throughout 130 days of stability testing when stored at −20 °C. The optimized method can be used for improving the quantification of fatty acids in both oils (fish and microalgal oils) and dry microalgal cells.

Tailoring enzymes for biofuel production with reference to Australian biomass

Manufacture of biofuels from existing biomass may provide a sustainable alternative to the extensive utilization of fossil fuels. Biomass offers environmental advantage over fossil fuels as it is a renewable energy source with low sulphur and nitrogen content and is carbon neutral over its production and utilization. Ranges of biomass are reported worldwide to be suitable raw material for bioethanol production. These can be generally classified into three groups; sucrose based (sugar cane), starch based (corn, wheat and barley) and lignocellulosic (which is mostly comprised of lignin, cellulose and hemicelluloses in grasses, wood and straw) materials. However, the limited supply of two biomass groups (sucrose and starch) will not satisfy society’s growing energy demands; thus biofuel technology based on lignocelluloses is under intense investigation. The main bottleneck in lignocellulosic biomass conversion for biofuel production is the enzymatic depolymerisation of cell wall polysaccharides into fermentable sugars. Protein engineering has recently been used to improve the performance of lignocelluloses degrading enzymes, as well as proteins involved in biofuel synthesis pathways. We have produced a recombinant enzyme that has the ability to produce monomeric sugars from a complex substrate. This presentation will summarize current efforts to develop an enzymatic treatment which would facilitate the economical processing of biomass available in Australia for bioenergy generation.

Biofuels from Australian biomass

The data comprises experimental results relating to the characterization of biomass.

Global patterns of epipelagic gelatinous zooplankton biomass

There is concern that overfishing may lead to a proliferation of jellyfish through a process known as fishing down the food web. However, there has been no global synthesis of patterns of gelatinous zooplankton biomass (GZB), an important first step in determining any future trends. A meta-analysis of epipelagic-GZB patterns was undertaken, encompassing 58 locations on a global scale, and spanning the years 1967–2009. Epipelagic-GZB decreased strongly with increasing total water column depth (r 2 = 0.543, p < 0.001, n = 58): in shallow (<50 m) coastal waters, epipelagic-GZB was typically 742× the levels in deep ocean (>2,000 m) sites. However, the ratio of GZB to primary productivity showed high values across a range of depths, i.e. this measure of the relative abundance of gelatinous zooplankton did not co-vary with depth.