Search bioRxiv⌕ Search

bioRxiv · 10.1101/2020.02.08.939876

Textile waste and microplastic induce activity and development of unique hydrocarbon-degrading marine bacterial communities

Abstract

Biofilm-forming microbial communities on plastics and textile fibers are of growing interest since they have potential to contribute to disease outbreaks and material biodegradability in the environment. Knowledge on microbial colonization of pollutants in the marine realm is expanding, but metabolic responses during substrate colonization remains poorly understood. Here, we assess the metabolic response in marine microbial communities to three different micropollutants, virgin high-density polyethylene (HDPE) microbeads, polysorbate-20 (Tween), and textile fibers. Intertidal textile fibers, mainly cotton, virgin HDPE, and Tween induced variable levels of microbial growth, respiration, and community assembly in controlled microcosm experiments. RAMAN characterization of the chemical composition of the textile waste fibers and high-throughput DNA sequencing data shows how the increased metabolic stimulation and biodegradation is translated into selection processes ultimately manifested in different communities colonizing the different micropollutant substrates. The composition of the bacterial communities colonizing the substrates were significantly altered by micropollutant substrate type and light conditions. Bacterial taxa, closely related to the well-known hydrocarbonoclastic bacteria Kordiimonas spp. and Alcanivorax spp., were enriched in the presence of textile-waste. The findings demonstrate an increased metabolic response by marine hydrocarbon-degrading bacterial taxa in the presence of microplastics and textile waste, highlighting their biodegradation potential. The metabolic stimulation by the micropollutants was increased in the presence of light, possibly due to photochemical dissolution of the plastic into smaller bioavailable compounds. Our results suggest that the development and increased activity of these unique microbial communities likely play a role in the bioremediation of the relatively long lived textile and microplastic pollutants in marine habitats. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=104 SRC="FIGDIR/small/939876v1_ufig1.gif" ALT="Figure 1"> View larger version (40K): org.highwire.dtl.DTLVardef@19322f3org.highwire.dtl.DTLVardef@dbae7dorg.highwire.dtl.DTLVardef@9c9d4aorg.highwire.dtl.DTLVardef@1aa636_HPS_FORMAT_FIGEXP M_FIG C_FIG

Source connections

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Girard, E., Kaliwoda, M., Schmahl, W. W., Woerheide, G., Orsi, W. D.. 2020-02-10. Textile waste and microplastic induce activity and development of unique hydrocarbon-degrading marine bacterial communities. https://doi.org/10.1101/2020.02.08.939876

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Cryo-EM Structure of Mycobacteriophage D29 Reveals a Specialized Portal-Capsid Junction and a Unique 13-Subunit Baseplate Collar

Mycobacteriophages are promising agents against drug-resistant mycobacterial infections, yet their structural organization and host-recognition mechanisms remain poorly understood. Here, we determined cryo-EM structures of the capsid, connector, tail tube, and baseplate of the lytic, broad-host-range mycobacteriophage D29, revealing a near-complete virion architecture. At the capsid-portal interface, five copies of the previously uncharacterized protein gp19.1 bridge adjacent capsid subunits around the dodecameric portal, potentially reinforcing the symmetry-mismatched vertex. At the baseplate, 13 copies of gp6 assemble into a collar surrounding the sixfold-symmetric gp23-gp27 core. Remarkably, this 6:13 symmetry mismatch is accommodated through six distinct gp6- gp27 interfaces involving 12 gp6 subunits, leaving one subunit largely disengaged from the core. This asymmetric organization produces a tilted, outward-flaring collar that presents an extensive surface with the potential to engage the host cell. Whole-cell binding and plaque-competition assays further implicate the gp6 collar and the flexible trimeric central fiber gp31 in host recognition. Together, these findings reveal distinct structural adaptations at symmetry-mismatched interfaces and provide a structural framework for understanding mycobacteriophage assembly and host engagement.

microbiology↗

A Luciferase Reporter of Ester Prodrug Delivery to the Cytosol of Intracellular Mycobacteria

The bacterial cell envelope restricts access to cytoplasmic targets and is a principal reason that otherwise potent antibacterial compounds fail in cells. Masking an anionic carboxylic acid as an ester is a common way to cross that barrier, but the strategy succeeds only if the target organism also hydrolyzes the ester once the compound arrives. These two requirements, permeation and intracellular unmasking, are rarely measured together in live bacterial cells, and existing reporters cannot specify where unmasking occurred. Here we describe a bioluminescent platform that resolves both steps in real time in live mycobacteria using carboxylate esters of D-luciferin. Luciferase requires that an ester both reach the bacterial cytoplasm and be hydrolyzed there, which makes light a compartment-specific readout of productive delivery. Across a series of alkyl esters in Mycobacterium smegmatis, chain length governed permeation while branching adjacent to the carbonyl governed esterase processing, indicating that the two parameters can be tuned independently. The n-butyl ester gave the strongest signal in broth, in infected macrophages, and in the pathogen Mycobacterium avium, whereas the tert-butyl ester was inert in Mycobacterium avium and unmasking of the whole series was attenuated at phagosomal pH. Ester activation is therefore both species- and compartment-dependent, and masking groups are best selected in the organism and environment in which they must act.

microbiology↗

Flexible phosphorus allocation to the phosphoproteome underpins diatom regulatory adaptations to fluctuating phosphate supply

Diatoms are major drivers of marine phosphorus (P) cycling and are highly adapted to cope with variable P supply. P-starved diatoms can sense increases in P availability within seconds, accumulating this limiting resource through luxury polyphosphate (polyP) storage. Yet, how diatoms coordinate such responses is unknown. Protein phosphorylation is a core mechanism for environmental signal transduction in eukaryotes, but how cells balance investment in protein phosphorylation against competing physiological demands during P limitation is poorly understood. Here, we characterise system-wide remodelling of the Phaeodactylum tricornutum phosphoproteome in response to P deficiency and subsequent resupply. We identify widespread proteome dephosphorylation across 44% of phosphosites, revealing a previously unrecognised P-sparing strategy in marine phytoplankton. Following P resupply, diatoms orchestrate extensive phosphoproteome reprogramming within minutes. We characterise previously unrecognized components for early recovery from P limitation, including a novel environmentally prevalent intracellular H+/phosphate transporter strongly conserved in diverse diatoms. We also identify a vacuolar Ca2+-dependent protein kinase (CDPK) associated with polyP-storage granules. Mutant and inhibitor analyses demonstrate a role for Ca2+- and CDPK-signalling in the regulation of luxury polyP accumulation. Our findings reveal that recovery from P starvation is mediated by rapid phosphoregulatory control of intracellular P trafficking, organellar ATP generation coupled with luxury P storage, enabling diatoms to exploit newly available P and thrive in fluctuating P regimes. Collectively, our study uncovers the phosphoproteome as a flexible intracellular P reservoir and establishes mechanistic links between intracellular P budgeting, signalling and the marine P cycle.

microbiology↗