Polyester degradation by soil bacteria: identification of conserved BHETase enzymes in Streptomyces.

The rising use of plastic results in an appalling amount of waste which is scattered into the environment. One of these plastics is PET which is mainly used for bottles. We have identified and characterized an esterase from Streptomyces, annotated as LipA, which can efficiently degrade the PET-derived oligomer BHET.

Compatible solutes determine the heat resistance of conidia.

Background: Asexually developed fungal spores (conidia) are key for the massive proliferation and dispersal of filamentous fungi. Germination of conidia and subsequent formation of a mycelium network give rise to many societal problems related to human and animal fungal diseases, post-harvest food spoilage, loss of harvest caused by plant-pathogenic fungi and moulding of buildings. Conidia are highly stress resistant compared to the vegetative mycelium and therefore even more difficult to tackle.

Comparative analysis reveals the modular functional structure of conjugative megaplasmid pTTS12 of S12: A paradigm for transferable traits, plasmid stability, and inheritance?

Originating from various environmental niches, large numbers of bacterial plasmids have been found carrying heavy metal and antibiotic resistance genes, degradation pathways and specific transporter genes for organic solvents or aromatic compounds. Such genes may constitute promising candidates for novel synthetic biology applications. Our systematic analysis of gene clusters encoded on megaplasmid pTTS12 from S12 underscores that a large portion of its genes is involved in stress response to increase survival under harsh conditions like the presence of heavy metal and organic solvent.

Toward Microbial Recycling and Upcycling of Plastics: Prospects and Challenges.

Annually, 400 Mt of plastics are produced of which roughly 40% is discarded within a year. Current plastic waste management approaches focus on applying physical, thermal, and chemical treatments of plastic polymers. However, these methods have severe limitations leading to the loss of valuable materials and resources.

Cell-to-cell heterogeneity of phosphate gene expression in yeast is controlled by alternative transcription, 14-3-3 and Spl2.

Dependent on phosphate availability the yeast Saccharomyces cerevisiae expresses either low or high affinity phosphate transporters. In the presence of phosphate yeast cells still express low levels of the high affinity phosphate transporter Pho84. The regulator Spl2 is expressed in approximately 90% of the cells, and is not expressed in the remaining cells.

Adaptive Laboratory Evolution Restores Solvent Tolerance in Plasmid-Cured Pseudomonas putida S12: a Molecular Analysis.

S12 is inherently solvent tolerant and constitutes a promising platform for biobased production of aromatic compounds and biopolymers. The megaplasmid pTTS12 of S12 carries several gene clusters involved in solvent tolerance, and the removal of this megaplasmid caused a significant reduction in solvent tolerance. In this study, we succeeded in restoring solvent tolerance in plasmid-cured S12 using adaptive laboratory evolution (ALE), underscoring the innate solvent tolerance of this strain.

Novel Toxin-Antitoxin Module SlvT-SlvA Regulates Megaplasmid Stability and Incites Solvent Tolerance in Pseudomonas putida S12.

S12 is highly tolerant of organic solvents in saturating concentrations, rendering this microorganism suitable for the industrial production of various aromatic compounds. Previous studies revealed that S12 contains the single-copy 583-kbp megaplasmid pTTS12. pTTS12 carries several important operons and gene clusters facilitating S12 survival and growth in the presence of toxic compounds or other environmental stresses.

Characterization of Eight Novel Spiroleptosphols from .

Chemical analyses of grown on banana medium resulted in eight novel spiroleptosphols, T1, T2 and U-Z (-). The structures were elucidated by a combination of high-resolution mass spectrometric data and 1- and 2-D NMR experiments. The relative stereochemistry was assigned by H coupling and NOESY/ROESY experiments.

Cold deacclimation mechanisms and reacclimation potential in flower buds of blackcurrant (Ribes nigrum).

As a consequence of global climate change, cold acclimation and deacclimation cycles are becoming increasingly frequent during winter in temperate regions. However, little is known about plant deacclimation and in particular reacclimation mechanisms, although deacclimation resistance and the ability to reacclimate may have wide-ranging consequences regarding plant productivity in a changing climate. Here, we report time-dependent responses of freezing tolerance, respiration rates, metabolite contents (high-resolution magic angle spinning NMR) and fatty acid levels (gas chromatography) in flower buds of two ecodormant Ribes nigrum cultivars exposed to three different deacclimation temperatures followed by a reacclimation treatment at 4°C.

Solvent Tolerance in Bacteria: Fulfilling the Promise of the Biotech Era?

The challenge of sustainably producing highly valuable chemical compounds requires specialized microbial cell factories because many of these compounds can be toxic to microbial hosts. Therefore, solvent-tolerant bacteria are promising production hosts because of their intrinsic tolerance towards these compounds. Recent studies have helped to elucidate the molecular mechanisms involved in solvent tolerance.

Regulation of solvent tolerance in Pseudomonas putida S12 mediated by mobile elements.

Organic solvent-tolerant bacteria are outstanding and versatile hosts for the bio-based production of a broad range of generally toxic aromatic compounds. The energetically costly solvent tolerance mechanisms are subject to multiple levels of regulation, involving among other mobile genetic elements. The genome of the solvent-tolerant Pseudomonas putida S12 contains many such mobile elements that play a major role in the regulation and adaptation to various stress conditions, including the regulation of expression of the solvent efflux pump SrpABC.

The fungal community changes over time in developing wheat heads.

Under normal conditions, wheat is colonized by a multitude of fungi that can have beneficial or adverse effects on plant growth and yield. To study the effect of spraying wheat heads with fungicides on the fungal community from emergence to harvest we applied an amplicon sequencing approach on single wheat heads. The climatic data showed that the spring of 2014 was very dry and without precipitation in the two weeks around flowering.

Dynamic Response of Pseudomonas putida S12 to Sudden Addition of Toluene and the Potential Role of the Solvent Tolerance Gene trgI.

Pseudomonas putida S12 is exceptionally tolerant to various organic solvents. To obtain further insight into this bacterium's primary defence mechanisms towards these potentially harmful substances, we studied its genome wide transcriptional response to sudden addition of toluene. Global gene expression profiles were monitored for 30 minutes after toluene addition.

Complete genome sequence of solvent-tolerant Pseudomonas putida S12 including megaplasmid pTTS12.

Pseudomonas putida S12 is a solvent-tolerant gamma-proteobacterium with an extensive track record for production of industrially relevant chemicals. Here we report the annotated complete genome sequence of this organism, including the megaplasmid pTTS12 which encodes many of the unique features of the S12 strain.

Crude glycerol as feedstock for the sustainable production of p-hydroxybenzoate by Pseudomonas putida S12.

Crude glycerol is a promising renewable feedstock in bioconversion processes for the production of fuels and chemicals. Impurities present in crude glycerol can however, negatively impact the fermentation process. Successful crude glycerol utilization requires robust microbial production hosts that tolerate and preferably, can utilize such impurities.

Identification of a quinone dehydrogenase from a Bacillus sp. involved in the decolourization of the lignin-model dye, Azure B.

In this study we have investigated the molecular background of the previously reported dye decolourization potential of Bacillus sp. LD003. Strain LD003 was previously isolated on Kraft lignin and was able to decolourize various lignin model dyes.

Metabolic and regulatory rearrangements underlying efficient D-xylose utilization in engineered Pseudomonas putida S12.

Previously, an efficient D-xylose utilizing Pseudomonas putida S12 strain was obtained by introducing the D-xylose isomerase pathway from Escherichia coli, followed by evolutionary selection. In the present study, systemic changes associated with the evolved phenotype were identified by transcriptomics, enzyme activity analysis, and inverse engineering. A key element in improving the initially poor D-xylose utilization was the redistribution of 6-phospho-D-gluconate (6-PG) between the Entner-Doudoroff pathway and the oxidative pentose phosphate (PP) pathway.

Cellular responses of Saccharomyces cerevisiae at near-zero growth rates: transcriptome analysis of anaerobic retentostat cultures.

Extremely low specific growth rates (below 0.01 h(-1) ) represent a largely unexplored area of microbial physiology. In this study, anaerobic, glucose-limited retentostats were used to analyse physiological and genome-wide transcriptional responses of Saccharomyces cerevisiae to cultivation at near-zero specific growth rates.

Microbial degradation of furanic compounds: biochemistry, genetics, and impact.

Microbial metabolism of furanic compounds, especially furfural and 5-hydroxymethylfurfural (HMF), is rapidly gaining interest in the scientific community. This interest can largely be attributed to the occurrence of toxic furanic aldehydes in lignocellulosic hydrolysates. However, these compounds are also widespread in nature and in human processed foods, and are produced in industry.

Isolation and characterization of novel bacterial strains exhibiting ligninolytic potential.

Background: To expand on the range of products which can be obtained from lignocellulosic biomass, the lignin component should be utilized as feedstock for value-added chemicals such as substituted aromatics, instead of being incinerated for heat and energy. Enzymes could provide an effective means for lignin depolymerization into products of interest. In this study, soil bacteria were isolated by enrichment on Kraft lignin and evaluated for their ligninolytic potential as a source of novel enzymes for waste lignin valorization.

Extreme calorie restriction and energy source starvation in Saccharomyces cerevisiae represent distinct physiological states.

Cultivation methods used to investigate microbial calorie restriction often result in carbon and energy starvation. This study aims to dissect cellular responses to calorie restriction and starvation in Saccharomyces cerevisiae by using retentostat cultivation. In retentostats, cells are continuously supplied with a small, constant carbon and energy supply, sufficient for maintenance of cellular viability and integrity but insufficient for growth.

Redundancy in putrescine catabolism in solvent tolerant Pseudomonas putida S12.

Pseudomonas putida S12 is a promising platform organism for the biological production of substituted aromatic compounds due to its extreme tolerance towards toxic chemicals. Solvent or aromatic stress tolerance may be due to membrane modifications and efflux pumps; however in general, polyamines have also been implicated in stressed cells. Previous transcriptomics results of P.

Improved p-hydroxybenzoate production by engineered Pseudomonas putida S12 by using a mixed-substrate feeding strategy.

The key precursors for p-hydroxybenzoate production by engineered Pseudomonas putida S12 are phosphoenolpyruvate (PEP) and erythrose-4-phosphate (E4P), for which the pentose phosphate (PP) pathway is an important source. Since PP pathway fluxes are typically low in pseudomonads, E4P and PEP availability is a likely bottleneck for aromatics production which may be alleviated by stimulating PP pathway fluxes via co-feeding of pentoses in addition to glucose or glycerol. As P.