Correlation of bio-optical properties with photosynthetic pigment and microorganism distribution in microbial mats from Hamelin Pool, Australia

TitleCorrelation of bio-optical properties with photosynthetic pigment and microorganism distribution in microbial mats from Hamelin Pool, Australia
Publication TypeJournal Article
Year of Publication2019
AuthorsFisher A., Wangpraseurt D., Larkum A.WD, Johnson M., Kuhl M., Chen M., Wong H.L, Burns B.P
JournalFems Microbiology Ecology
Volume95
Date Published2019/01
Type of ArticleArticle
ISBN Number0168-6496
Accession NumberWOS:000453664200017
Keywordsarchaeal; bacterial; chlorophyll; diversity; ecology; exopolymeric substances; Hamelin Pool; insights; light; microbial mats; microbiology; phototrophy; pigments; shark bay; stromatolite
Abstract

Microbial mats and stromatolites are widespread in Hamelin Pool, Shark Bay, however the phototrophic capacity of these systems is unknown. This study has determined the optical properties and light-harvesting potential of these mats with light microsensors. These characteristics were linked via a combination of 16S rDNA sequencing, pigment analyses and hyperspectral imaging. Local scalar irradiance was elevated over the incident downwelling irradiance by 1.5-fold, suggesting light trapping and strong scattering by the mats. Visible light (400-700 nm) penetrated to a depth of 2 mm, whereas near-infrared light (700-800 nm) penetrated to at least 6 mm. Chlorophyll a and bacteriochlorophyll a (Bchl a) were found to be the dominant photosynthetic pigments present, with BChl a peaking at the subsurface (2-4 mm). Detailed 16S rDNA analyses revealed the presence of putative Chl f-containing Halomicronema sp. and photosynthetic members primarily decreased from the mat surface down to a depth of 6 mm. Data indicated high abundances of some pigments and phototrophic organisms in deeper layers of the mats (6-16 mm). It is proposed that the photosynthetic bacteria present in this system undergo unique adaptations to lower light conditions below the mat surface, and that phototrophic metabolisms are major contributors to ecosystem function.

DOI10.1093/femsec/fiy219
Short TitleFEMS Microbiol. Ecol.
Student Publication: 
No
Research Topics: 
sharknado