Flow-based method for biofilm microbiota enrichment and exploration of metagenomes.

Most bacteria live in biofilms in their natural habitat rather than the planktonic cell stage that dominates during traditional laboratory cultivation and enrichment schemes. The present study describes the establishment of a flow-based enrichment method based on multispecies biofilm communities for directing biofilm functionality using an environmental inoculum. By controlling flow conditions and physio-chemical properties, the set-up aims to simulate natural conditions ex situ for biofilm formation.

sp. nov.: A Slow-Growing Actinobacterium Producing Candicidin, Isolated From Sediments of the Trondheim Fjord.

Marine environments are home to an extensive number of microorganisms, many of which remain unexplored for taxonomic novelty and functional capabilities. In this study, a slow-growing strain expressing unique genomic and phenotypic characteristics, P38-E01 , was described using a polyphasic taxonomic approach. This strain is part of a collection of over 8,000 marine Actinobacteria isolates collected in the Trondheim fjord of Norway by SINTEF Industry (Trondheim, Norway) and the Norwegian University of Science and Technology (NTNU, Trondheim, Norway).

Streptomyces poriferorum sp. nov., a novel marine sponge-derived Actinobacteria species expressing anti-MRSA activity.

Marine sponges represent a rich source of uncharacterized microbial diversity, and many are host to microorganisms that produce biologically active specialized metabolites. Here, a polyphasic approach was used to characterize two Actinobacteria strains, P01-B04 and P01-F02, that were isolated from the marine sponges Geodia barretti (Bowerbank, 1858) and Antho dichotoma (Esper, 1794), respectively. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strains P01-B04 and P01-F02 are closely related to Streptomyces beijiangensis DSM 41794, Streptomyces laculatispora NRRL B-24909, and Streptomyces brevispora NRRL B-24910.

Multiplex droplet digital PCR assay for detection of Flavobacterium psychrophilum and Yersinia ruckeri in Norwegian aquaculture.

We report the development of ddPCR assays for single and simultaneous detection of the bacterial pathogens Flavobacterium psychrophilum and Yersinia ruckeri in water from land-based recirculation aquaculture systems (RAS), producing Atlantic salmon (Salmo salar) smolt. The method was tested and verified for use in water analyses from RAS production sites, and proved to be specific and with sensitivity 0.0011 ng DNA for F.

Biodegradation of n-alkanes on oil-seawater interfaces at different temperatures and microbial communities associated with the degradation.

Oil biodegradation studies have mainly focused on microbial processes in dispersions, not specifically on the interfaces between the oil and the seawater in the dispersions. In this study, a hydrophobic adsorbent system, consisting of Fluortex fabrics, was used to investigate biodegradation of n-alkanes and microbial communities on oil-seawater interfaces in natural non-amended seawater. The study was performed over a temperature range from 0 to 20 °C, to determine how temperature affected biodegradation at the oil-seawater interfaces.

The role of active site aromatic residues in substrate degradation by the human chitotriosidase.

Human chitotriosidase (HCHT) is a glycoside hydrolase family 18 chitinase synthesized and secreted in human macrophages thought be an innate part of the human immune system. It consists of a catalytic domain with the (β/α)8 TIM barrel fold having a large area of solvent-exposed aromatic amino acids in the active site and an additional family 14 carbohydrate-binding module. To gain further insight into enzyme functionality, especially the effect of the active site aromatic residues, we expressed two variants with mutations in subsites on either side of the catalytic acid, subsite -3 (W31A) and +2 (W218A), and compared their catalytic properties on chitin and high molecular weight chitosans.