Despite many advances in research on photosynthetic carbon fixation in marine diatoms, the biophysical and biochemical mechanisms of extracellular polysaccharide production remain significant challenges to be resolved at the molecular scale in order to proceed toward an understanding of their functions at the cellular level, as well as their interactions and fate in the ocean. This review cover...

Noctiluca scintillans was seasonally abundant during the austral spring and summer with typical values of 16 cells l–1, but depleted in autumn and winter, with values of <1 cell l–1. Peaks in abundance of up to 79 cells l–1 were observed, at the same time or subsequent to diatom blooms which were caused by episodic uplifting events during the spring and summer. The diatom blooms were dominated ...

Analysis of siliceous microfossils of a 79 cm long peat sediment core from Highlands Hammock State Park, Florida, revealed distinct changes in the local hydrology during the past 2,500 years. The coring site is a seasonally inundated forest where water availability is directly influenced by precipitation. Diatoms, chrysophyte statospores, sponge remains and phytoliths were counted in 25 samples...

Stable isotope analysis of sedimentary carbon in lakes can help reveal changes in terrestrial and aquatic carbon cycles. A method based on a single, photosynthetic organism, where host effects are minimised, should offer more precision than carbon isotope studies of bulk lake sediments. Here we report the development of a systematic method for use on fossil lacustrine diatom frustules, adapted ...

The main purpose of this research is to develop methods for automatic identification of biological specimens in digital photographs and drawings held in a database. Incorporation of taxonomic drawings into a visual indexing system has not been attempted to date. Diatoms are a single cell microscopic algae that provide a particularly suitable case study. Identification of diatoms is a challengin...

Living organisms are adept in forming inorganic materials (biominerals) with unique structures and properties that exceed the capabilities of engineered materials. Biomimetic materials syntheses are being developed that aim at replicating the advantageous properties of biominerals in vitro and endow them with additional functionalities. Recently, proof-of-concept was provided for an alternative...

The marine diatom Phaeodactylum tricornutum is an important basal resource in the marine food chain and is used as a standard test organism in toxicological studies. In this study, in vivo experiments were performed to analyze the effects of 1-octyl-3-methylimidazolium bromide ([C8mim]Br) on the growth, photosynthetic activity, and antioxidant enzymes of P. tricornutum using 96 h growth tests i...

We examined diatom assemblages from 18 stream and pond samples in the Franz Josef Land Archipelago (FJL), the most northern land of Eurasia. More than 216 taxa were observed, revealing a rich circumpolar diatom flora, including many undescribed taxa. Widely distributed taxa were the most abundant by cell densities, while circumpolar taxa were the most species rich. Stream and pond habitats host...

Accurate taxonomic resolution in light microscopy analyses of microalgae is essential to achieve high quality, comparable results in both floristic analyses and biomonitoring studies. A number of closely related diatom taxa have been detected to date co-occurring within benthic diatom assemblages, sharing many morphological, morphometrical and ecological characteristics. In this contribution, w...

Photoautotrophic biofilms play an important role in various aquatic habitats and are composed of prokaryotic and/or eukaryotic organisms embedded in extracellular polymeric substances (EPS). We have isolated diatoms as well as bacteria from freshwater biofilms to study organismal interactions between representative isolates. We found that bacteria have a strong impact on the biofilm formation o...