Pushing the limits: expanding the temperature tolerance of a coral photosymbiont through differing selection regimes.

Coral thermal bleaching resilience can be improved by enhancing photosymbiont thermal tolerance via experimental evolution. While successful for some strains, selection under stable temperatures was ineffective at increasing the thermal threshold of an already thermo-tolerant photosymbiont (Durusdinium trenchii). Corals from environments with fluctuating temperatures tend to have comparatively high heat tolerance.

Chemical mutagenesis and thermal selection of coral photosymbionts induce adaptation to heat stress with trait trade-offs.

Despite the relevance of heat-evolved microalgal endosymbionts to coral reef restoration, to date, few Symbiodiniaceae strains have been thermally enhanced via experimental evolution. Here, we investigated whether the thermal tolerance of Symbiodiniaceae can be increased through chemical mutagenesis followed by thermal selection. Strains of , and were exposed to ethyl methanesulfonate to induce random mutagenesis, and then underwent thermal selection at high temperature (31/33°C).

Physiological Characterization of the Coral Holobiont Using a New Micro-Respirometry Tool.

Metabolic activity, defined as the sum of organismal processes that involve energy, is of critical importance in understanding the function and evolution of life on earth. Measuring organismal metabolic rates is, therefore, at the center of explaining the physiological states of organisms, their ecological roles, and the impact of environmental change on species within terrestrial and aquatic ecosystems. On coral reefs, measures of metabolism have been used to quantify symbiosis functioning between corals and their obligate algal symbionts (Symbiodiniaceae), as well as assess how environmental stressors, including climate change, will impact coral health.

Co-dynamics of Symbiodiniaceae and bacterial populations during the first year of symbiosis with Acropora tenuis juveniles.

Interactions between corals and their associated microbial communities (Symbiodiniaceae and prokaryotes) are key to understanding corals' potential for and rate of acclimatory and adaptive responses. However, the establishment of microalgal and bacterial communities is poorly understood during coral ontogeny in the wild. We examined the establishment and co-occurrence between multiple microbial communities using 16S rRNA (bacterial) and ITS2 rDNA (Symbiodiniaceae) gene amplicon sequencing in juveniles of the common coral, Acropora tenuis, across the first year of development.

Genetic, morphological and growth characterisation of a new Roseofilum strain (Oscillatoriales, Cyanobacteria) associated with coral black band disease.

Black band disease (BBD) is a common disease of reef-building corals with a worldwide distribution that causes tissue loss at a rate of up to 3 cm/day. Critical for a mechanistic understanding of the disease's aetiology is the cultivation of its proposed pathogen, filamentous cyanobacteria (genus Roseofilum). Here, we optimise existing protocols for the isolation and cultivation of Roseofilum cyanobacteria using a new strain from the central Great Barrier Reef.

Culture scale-up and immobilisation of a mixed methanotrophic consortium for methane remediation in pilot-scale bio-filters.

Robust methanotrophic consortia for methane (CH) remediation and by-product development are presently not readily available for industrial use. In this study, a mixed methanotrophic consortium (MMC), sequentially enriched from a marine sediment, was assessed for CH removal efficiency and potential biomass-generated by-product development. Suitable packing material for bio-filters to support MMC biofilm establishment and growth was also evaluated.

First use of the WAVE™ disposable rocking bioreactor for enhanced bioproduct synthesis by N2 -fixing cyanobacteria.

WAVE™ rocking disposable bioreactors have been successfully utilized for bioproduct development from bacteria, yeast, microalgae, and animal and plant cells but not from cyanobacteria so far. N2 -fixing cyanobacteria represent a prolific bioproducts source with reduced cultivation costs. In this study, 1 L cultures of the N2 -fixing cyanobacterium Anabaena siamensis grown diazotrophically in the WAVE™ bioreactor exhibited increased phosphate consumption and 37-70% higher CO2 fixation rates than those grown in conventional bubbled suspension (BS) batch cultures.

First report of microcystin-producing Fischerella sp. (Stigonematales, Cyanobacteria) in tropical Australia.

A polyphasic study of four Stigonematales cyanobacteria from tropical Australia (Queensland) revealed production of the hepatotoxins microcystins (MC-LR, MC-LA, MC-LF, MC-FR and demethyl-MC-LR) by Fischerella sp. NQAIF311 isolated from a seasonal creek. Total microcystin content reached 43 μg g(-1) dry weight.