Biology subjects

Bentzon-Tilia, M.

Publications and source records attributed to Bentzon-Tilia, M..

5 recordsLinked to original sources

bioRxiv2026

Viscoelastic flow-integrated Raman spectroscopy platform

We demonstrate the first viscoelastic-based flow-integrated Raman spectroscopy (FIRS) platform using spontaneous Raman spectroscopy with a simplified fluidic design that precisely controls particle transit speed and predicts arrival time to the Raman interrogation region, together with time synchronized triggered acquisition. Using viscoelastic flow focusing and optical detection of velocity for hardware triggering, the setup enables high-throughput, real-time Raman analysis of particles in continuous flow. The system operates with a single pressure pump, two sets of fiber-coupled lasers and detectors, and a microcapillary precisely aligned in a projection micro-stereolithography 3D-printed mount, and ensures detection stability across various flow rates. The demonstrated platform is modular and scalable. Detection rates of up to 80 cells per minute were achieved and dinoflagellate Alexandrium ostenfeldii cultures were analyzed. The integrated optical trigger mechanism supports future extensions such as cell sorting or additional analyses. A user-friendly graphical interface provides full control of fluidics, spectroscopy, and real-time monitoring, making this compact, low-cost FIRS platform accessible across a wide range of laboratory environments.

molecular biology↗

bioRxiv2025

An integrated meta-omics approach for identifying candidate organic micropollutant degraders in complex microbial communities

Biotransformation is a significant determinant of the fate of organic micropollutants (OMPs) in natural and engineered environments; yet identifying OMP-transforming microorganisms remains challenging. Integrating metagenomics and metatranscriptomics, we searched for correlations between the biotransformation of ammonia and atenolol and the transcriptional activity of metagenome-assembled genomes (MAGs) across five nitrifier-rich cultures in batch experiments. The biotransformation of ammonia correlated with the activity of ammonia-oxidizing bacterium Nitrosomonas europaea but not with the activity of other bacteria, including several ammonia oxidizers. Additionally, the biotransformation of ammonia correlated with the transcript abundance of the ammonia monooxygenase (AMO) expressed by N. europaea but not with the transcript abundance of AMO at the community level. Atenolol biotransformation correlated with the activity of four MAGs representing three heterotrophic genera: Terrimonas, Flavobacterium, and Zeimonas. It did not correlate with the total transcript abundance of any member of a comprehensive set of amidohydrolases, which are predicted to transform this drug. By contrast, it correlated with the expression of the amidohydrolase asparagine synthase (AsnB) identified in the Terrimonas and Flavobacterium MAGs. In summary, we present a novel association-based method for elucidating biotransformation processes robust to variability in enzyme reaction kinetics with implications for OMP control. SynopsisThe fate of organic micropollutants in natural and engineered systems depends greatly on biotransformation by microbes. This study proposes an approach for identifying these microbes with implications for the study and control of organic micropollutant removal. ABSTRACT GRAPHICS O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=97 SRC="FIGDIR/small/639455v1_ufig1.gif" ALT="Figure 1"> View larger version (17K): org.highwire.dtl.DTLVardef@17c7f1org.highwire.dtl.DTLVardef@147b9eforg.highwire.dtl.DTLVardef@1fffc9eorg.highwire.dtl.DTLVardef@121fd96_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

bioRxiv2025

Psychromonas aestuarii sp. nov., a novel bacterial species isolated from estuarine surface sediment

Using an isolation chip (iChip), two bacterial strains, MME1T and MME2, exhibiting ovoid to curved rod cell morphologies and white-cream colony pigmentation were isolated from the surface of estuarine sediment at Niv[a] Bugt Strandenge Bird Sanctuary, Denmark (55{degrees}5542.6N 12{degrees}3123.6E). Analysis of the 16S rRNA gene sequence of these isolates suggested them to be members of the genus Psychromonas, as both had above 97.5 % 16S rRNA gene similarity with Psychromonas aquimarina strain JAMM 0404T. Further genomic comparisons suggested MME strains to be representatives of a novel species, having an average nucleotide identity (ANI) < 85 % relative to all other genome sequenced species of the Psychromonas genus. The G+C content was 39.5 mol %. The species was facultative anaerobic, growing optimally at 15 - 20 {degrees}C and pH 7.0. The optimal salinity was lower than for other described species of the genus with 1 - 2 % NaCl, reflecting the estuarine source of isolation. GC-MS analyses identified C16:0, C16:1{omega}7c/ C16:1{omega}7t/ and C14:03OH as the predominant cellular fatty acids. Based on molecular, phenotypic, and chemotaxonomic analyses, we propose that MME1 and MME2 represent a novel species of the genus Psychromonas with the name Psychromonas aestuarii sp. nov. with the MME1T (= DSM 118464T =LMG 33722T) as the type strain.

microbiology↗

bioRxiv2023

Impact of host species on assembly, composition, and functional profiles of phycosphere microbiomes

Microalgal microbiomes play vital roles in the growth and health of their host, however, their composition and functions remain only partially characterized, especially across microalgal phyla. In this study, a natural seawater microbiome was introduced to three distinct, axenic species of microalgae, the haptophyte Isochrysis galbana, the chlorophyte Tetraselmis suecica, and the diatom Conticribra weissflogii (previously Thalassiosira), and its divergence and assembly was monitored over 49 days using 16S rRNA amplicon and metagenomic analyses. The microbiomes had a high degree of host specificity in terms of taxonomic composition and potential functions, including CAZymes profiles. Rhodobacteraceae and Flavobacteriaceae families were abundant across all microalgal hosts, but I .galbana microbiomes diverged further from T. suecica and C. weissflogii microbiomes. I .galbana microbiomes had a much higher relative abundance of Flavobacteriaceae, whereas the two other algal microbiomes had higher relative abundances of Rhodobacteraceae. This could be due to the mixotrophic nature of I. galbana affecting the carbohydrate composition available to the microbiomes, which was supported by the CAZymes profile of I. galbana microbiomes diverging further from those of T. suecica and C. weissflogii microbiomes. Finally, the presence of denitrification and other anaerobic pathways was found exclusively in microbiomes of C. weissflogii potentially resulting from anoxic microenvironments in aggregates formed by this diatom during the experiment. These results underline the deterministic role of the microalgal host species on microbiome composition and functional profiles along with other factors, such as trophic mode of the microalgal host. ImportanceAs the main primary producers of the oceans, microalgae serve as cornerstones of the ecosystems they are part of. Additionally, they are increasingly used for biotechnological purposes such as the production of nutraceuticals, pigments, and antioxidants. Since the bacterial microbiomes of microalgae can affect their hosts in beneficial and detrimental ways, understanding these microbiomes is crucial to both ecological and applied roles of microalgae. The present study advances the understanding of microalgal microbiome assembly, composition, and functionality across microalgal phyla, which may inform modeling and engineering of microalgal microbiomes for biotechnological purposes.

microbiology↗

bioRxiv2018

Phylogenetic distribution of roseobacticides in the Roseobacter group and their effect on microalgae

The Roseobacter-group species Phaeobacter inhibens produces the antibacterial tropodithietic acid (TDA) and the algaecidal roseobacticides with both compound classes sharing part of the same biosynthetic pathway. The purpose of this study was to investigate the production of roseobacticides more broadly in TDA-producing roseobacters and to compare the effect of producers and non-producers on microalgae. Of 33 roseobacters analyzed, roseobacticide production was a unique feature of TDA-producing P. inhibens, P. gallaeciensis and P. piscinae strains. One TDA-producing Phaeobacter strain, 27-4, was unable to produce roseobacticides, possibly due to a transposable element. TDA-producing Ruegeria mobilis and Pseudovibrio did not produce roseobacticides. Addition of roseobacticide-containing bacterial extracts affected the growth of the microalgae Rhodomonas salina, Thalassiosira pseudonana and Emiliania huxleyi, while growth of Tetraselmis suecica was unaffected. During co-cultivation, growth of E. huxleyi was initially stimulated by the roseobacticide producer DSM 17395, while the subsequent decline in algal cell numbers during senescence was enhanced. Strain 27-4 that does not produce roseobacticides had no effect on algal growth. Both bacterial strains, DSM 17395 and 27-4, grew during co-cultivation presumably utilizing algal exudates. Furthermore, TDA-producing roseobacters have potential as probiotics in marine larviculture and it is promising that the live feed Tetraselmis was unaffected by roseobacticides-containing extracts.\n\nOriginality-significance statementSome Roseobacter-group bacteria produce the antibacterial compound tropodithetic acid (TDA) and have potential as probiotics in marine aquaculture. However, a few of these strains additionally produce algaecidal compounds, the roseobacticides, which would restrict their use in marine larviculture where algae are used as live feed for fish larvae. We herein found that roseobacticides are limited to TDA-producing Phaeobacter strains and were not biosynthesized by TDA-producers outside this genus. Roseobacticides affected several strains of microalgae, but not the chlorophyte that is used as live feed in the aquaculture industry. Thus, the application of Roseobacter strains as probiotics is not hampered. Furthermore, these results demonstrate how Roseobacter-group strains act as gardeners of microalgae and thereby would be involved in environmental processes on a larger scale.

microbiology↗