Surveying a Diverse Pool of Microalgae as a Bioresource for Future Biotechnological Applications

Abstract

Resource limitation is an escalating concern given human expansion and development. Algae are increasingly recognised as a promising bioresource and the range of cultivated species and their products is expanding. Compared to terrestrial crops, microalgae are very biodiverse and offer considerable versatility for a range of biotechnological applications including the production of animal feeds, fuels, high value products and waste-water treatment. Despite their versatility and capacity for high biomass productivity on non-arable land, attempts to harness microalgae for commercial benefit have been limited. This is in large part due to capital costs and energy inputs remaining high, the necessity of identifying 'suitable' land with proximal resource and infrastructure availability and the need for process and strain optimisation. Microalgae represent a relatively unexplored bioresource both for native and engineered strains. Success in this area requires (1) appropriate methods to source and isolate microalgae strains, (2) efficient maintenance of motherstocks, (3) rapid strain characterisation and correct matching of strains to applications, (4) ensuring productive and stable cultivation at scale, and (5) ongoing strain development (breeding, adaptation and engineering). This article illustrates a survey and isolation of over 150 local microalgae strains as a bioresource for ongoing strain development and biotechnological applications.

High-throughput screen for high performance microalgae strain selection and integrated media design

“…Algae isolates were identified using morphological investigation and molecular classification by 18S and 16S rDNA analysis [15]. Sequences were aligned using nucleotide BLAST (NCBI, http://blast.ncbi.nlm.nih.gov/Blast.cgi) against the 'nucleotide collection (nr/nt)' database.…”

“…100 algae isolates were obtained from an in-house established strain library holding a broad range of indigenous Australian species sampled from the east and south of Australia as described in [15]. Algae isolates were identified using morphological investigation and molecular classification by 18S and 16S rDNA analysis [15].…”

“…Their ancient lineage (1.5-2 billion years since divergence from plants) and ability to colonise a broad range of ecological niches have led to the evolution of an estimated 350,000 species [1] and possibly more, providing a valuable genetic resource for breeding and genetic engineering. While to date, research has focussed on a limited number of production strains, rapid advances are being made in algae bio-prospecting [3,6,15,28,37], species purification [15], cryo-preservation [2] and genetic engineering [26,27,32]. However, given the diversity of microalgae, their specific production conditions must be individually optimised before their potential and handling requirements can be fully assessed.…”

“…Here we have employed an advanced high-throughput robotic screen designed to identify the best nutrient conditions for a diverse set of 100 new isolated algae strains [15] within this complex multidimensional statistical space [25]. The screen included the above 21 mineral elements as well as vitamins B 1 and B 12 , and focuses on the statistical optimisation of the 12 most important of these.…”

Experimental Investigations of Physical and Chemical Properties for Microalgae HTL Bio-Crude Using a Large Batch Reactor

“…which had been isolated as part of previous work [35] was used for these experiments. The Scenedesmus sp.…”