Eucalypts as a biofuel feedstock

Abstract

Eucalypts are both a proven but largely unexplored source of woody biomass for biofuel production. Few of the some 900 species have been evaluated for cropping, yet among them are the most productive and versatile biomass species in the world, grown in over 90 countries, with species found to suit most tropical and temperate climates. The biology, science and technology underlying the breeding and growing of eucalypts and their potential for biofuel production are reviewed. How eucalypts meet sustainability and economic criteria for biofuel feedstocks, and the advantages of woody feedstocks broadly, are considered. Relevant aspects of eucalypt taxonomy, evolution, natural distribution, human dispersal, composition, domestication and biotechnology of the groups' potential as a biofuel feedstock resource are reviewed. Two case studies are outlined, illustrating species identification, domestication and harvesting processes where eucalypts are prospective biofuel feedstocks. Eucalypts are strong contenders as a universal woody biomass feedstock for biofuel.

Tissue Culture of Corymbia and Eucalyptus

“…However, B5 medium with 146 mM sucrose has been used for initiating somatic embryos on C. citriodora cotyledons [132], and N7 medium [118] has been used for callogenesis and somatic embryo formation from E. urophylla hypocotyls [86]. MS nutrient levels are generally not adjusted for somatic embryogenesis although half-strength MS medium with one-sixth CaCl 2 has been used for E. dunnii [81] and MS medium with half-strength KNO 3 and NH 4 NO 3 has been used for E. microtheca [121]. Embryogenic callus is often, though not always, induced in darkness.…”

“…Half-strength KNO 3 and NH 4 NO 3 have been used in full-strength MS medium for E. microtheca F.Muell. organogenesis [121].…”

“…Reduced levels of mineral nutrients have also been used in some establishment media. For example, reduced levels of NH 4 NO 3 and KNO 3 have been used in MS-based establishment media for C. citriodora nodes [80] and greatly reduced CaCl 2 levels have been used during in vitro germination of E. dunnii, E. globulus, and E. saligna seeds [81][82][83][84].…”

“…The concentrations of KNO 3 and NH 4 NO 3 have been reduced by half in full-strength MS media for shoot culture of C. citriodora [80]. Shoots of C. torelliana × C. torelliana exhibit micronutrient deficiencies in half-strength MS medium, but shoot proliferation and shoot length are not increased by using full-strength MS medium or by doubling the micronutrient levels in half-strength MS medium [46].…”

“…Eucalypts are the world's most widely planted hardwood trees, with more than 20 million hectares established in plantations because of their wide diversity of species, suitability of individual species for different climates and soils, fast growth rates, and multiple products such as timber, pulp, fodder, biofuel, essential oil, and bioactive chemicals [1][2][3][4][5][6][7][8][9][10][11]. Eucalypt plantations are dominated by ten species, Corymbia citriodora (Hook.)…”