Microbial biofilms as a platform for diverse biocatalytic applications.

Microbial biofilms have gained significant traction in commercial wastewater treatment due to their inherent resilience, well-organized structure, and potential for collaborative metabolic processes. As our understanding of their physiology deepens, these living catalysts are finding exciting applications beyond wastewater treatment, including the production of bulk and fine chemicals, bioelectricity generation, and enzyme immobilization. While the biological applications of biofilms in different biocatalytic systems have been extensively summarized, the applications of artificially engineered biofilms were rarely discussed.

Bioengineering Comamonas testosteroni CNB-1: a robust whole-cell biocatalyst for efficient PET microplastic degradation.

The escalating crisis of polyethylene terephthalate (PET) microplastic contamination in biological wastewater treatment systems is a pressing environmental concern. These microplastics inevitably accumulate in sewage sludge due to the absence of effective removal technologies. Addressing this urgent issue, this study introduces a novel approach using DuraPETase, a potent enzyme with enhanced PET hydrolytic activity at ambient temperatures.

Maximizing the benefits of biofilms in fermentation processes.

Biofilm-based fermentation has great potential, as it possesses inherent characteristics such as self-immobilization, high resistance to reactants, and long-term activity. This forum focuses on research targets for promoting biofilm engineering to maximize the beneficial features of biofilms and to effectively utilize them in biofilm-mediated fermentation.

Attractant and repellent induce opposing changes in the four-helix bundle ligand-binding domain of a bacterial chemoreceptor.

Motile bacteria navigate toward favorable conditions and away from unfavorable environments using chemotaxis. Mechanisms of sensing attractants are well understood; however, molecular aspects of how bacteria sense repellents have not been established. Here, we identified malate as a repellent recognized by the MCP2201 chemoreceptor in a bacterium Comamonas testosteroni and showed that it binds to the same site as an attractant citrate.

Enhancing rhamnolipid production through a two-stage fermentation control strategy based on metabolic engineering and nitrate feeding.

Nitrate plays a crucial role in the high-efficient fermentation production of rhamnolipids (RLs). However, the underlying mechanism remains unclear. Firstly, by knocking out the restriction endonuclease PaeKI and utilizatiing the endogenous CRISPR-Cas-mediated single-plasmid recombineering system, a genome editing system for P.

Future focuses of enzymatic plastic degradation.

Enzyme-based plastic degradation and valorization of the plastic-derived monomers has emerged as a potent option to address the plastic waste dilemma. Obstacles in implementing the enzymatic degradation of plastics in industry are here summarized, and strategies to overcome these obstacles are discussed to exploit the full potential of enzymatic plastic degradation toward a sustainable plastic economy.

Integration of ARTP Mutation and Adaptive Laboratory Evolution to Reveal 1,4-Butanediol Degradation in Pseudomonas putida KT2440.

Biotransformation of plastics or their depolymerization monomers as raw materials would offer a better end-of-life solutions to the plastic waste dilemma. 1,4-butanediol (BDO) is one of the major depolymerization monomers of many plastics polymers. BDO valorization presents great significance for waste plastic up-recycling and fermenting feedstock exploitation.

Biodegradation of polyester polyurethane by Cladosporium sp. P7: Evaluating its degradation capacity and metabolic pathways.

Microorganisms capable of decomposing polyurethane (PU) and other plastics have the potential to be used in bio-recycling processes. In this study, 20 PU-degrading strains were isolated, including 11 bacteria and 9 fungi, using a synthesized poly(1,4-butylene adipate)-based PU (PBA-PU) as the screening substrate. Three PU substrates with increasing structure complexities were used for a thorough evaluation of microbial degradation capacity: Impranil® DLN-SD, PBA-PU film and PU foam waste.

Priority changes between biofilm exopolysaccharides synthesis and rhamnolipids production are mediated by a c-di-GMP-specific phosphodiesterase NbdA in .

The synthesis of biofilm exopolysaccharides and rhamnolipids (RLs) are two interrelated processes in , but how bacteria coordinate these two processes remains unclear. We collected a KT1115 with rugose small colony variant (RSCV) phenotype from soil, and used it to study the dynamic regulation mechanism of biofilm polysaccharide and RLs synthesis. The results showed that the overproduction of biofilm exopolysaccharides at biofilm stage ultimately contributed the surge of RLs production at RLs stage.

Toward a unified nomenclature for strains with hyper-biofilm phenotypes.

Hyper-biofilm strains form robust biofilms, are highly adaptable, and form highly tolerant subpopulations in biofilms grown in vivo and in vitro. Such subpopulations are formed by a wide range of bacteria and thus have been given different names in different species. This situation calls for the establishment of a unified nomenclature for strains with hyper-biofilm phenotypes.

Application of a novel fluorogenic polyurethane analogue probe in polyester-degrading microorganisms screening by microfluidic droplet.

Application of polyester-degrading microorganisms or enzymes should be considered as an eco-friendly alternative to chemical recycling due to the huge plastic waste disposal nowadays. However, current impranil DLN-based screening of polyester-degrading microorganisms is time-consuming, labour-intensive and unable to distinguish polyesterases from other protease- or amidase-like enzymes. Herein, we present an approach that combined a novel synthetic fluorescent polyurethane analogue probe (FPAP), along with the droplet-based microfluidics to screen polyurethane-degrading microorganisms through fluorescence-activated droplet sorting (FADS) pipeline.

[Microplastics in wastewater treatment: current status and future trends].

Microplastics (MPs) have been detected in many ecosystems, such as the ocean, land and the atmosphere. A large number of MPs in urban sewage are trapped in the activated sludge by sewage treatment plants, but tens of thousands of MPs 'escape' the treatment and are discharged into the nature. Meanwhile, most of the MPs are transferred into the activated sludge during sewage treatment, and the sludge will be further used in agriculture, leading to secondary pollution of the MPs.

Construction and comparison of synthetic microbial consortium system (SMCs) by non-living or living materials immobilization and application in acetochlor degradation.

The microbial degradation of pesticides by pure or mixed microbial cultures has been thoroughly explored, however, they are still difficult to apply in real environmental remediation. Here, we constructed a synthetic microbial consortium system (SMCs) through the immobilization technology by non-living or living materials to improve the acetochlor degradation efficiency. Rhodococcus sp.

Biodegradation of polyether-polyurethane foam in yellow mealworms (Tenebrio molitor) and effects on the gut microbiome.

Polyurethane (PU) is one of the mass-produced recalcitrant plastics with a high environmental resistance but extremely low biodegradability. Therefore, improperly disposed PU waste adds significantly to plastic pollution, which must be addressed immediately. In recent years, there has been an increasing number of reports on plastic biodegradation in insect larvae, especially those that can feed on polyethylene and polystyrene.

Transcription-Associated Fluorescence-Activated Droplet Sorting for Di-rhamnolipid Hyperproducers.

Rhamnolipids (RLs) are biosurfactants with great economic significance that have been used extensively in multiple industries. is a promising microorganism for sustainable RL production. However, current CTAB-MB based screening of RL-producing strains is time-consuming, labor-intensive, and unable to distinguish mono- and di-RL.

Rugose small colony variant and its hyper-biofilm in Pseudomonas aeruginosa: Adaption, evolution, and biotechnological potential.

One of the hallmarks of the environmental bacterium Pseudomonas aeruginosa is its excellent ecological flexibility, which can thrive in diverse ecological niches. In different ecosystems, P. aeruginosa may use different strategies to survive, such as forming biofilms in crude oil environment, converting to mucoid phenotype in the cystic fibrosis (CF) lung, or becoming persisters when treated with antibiotics.

[Isolation and characterization of a polyurethane-degrading bacterium].

Biodegradation of polyurethane (PUR) pollutants by microorganisms has received widespread attention currently. Identification of microorganisms capable of efficiently degrading PUR plastics is a key point. In this study, a strain P10 capable of degrading PUR was isolated from the plastic wastes, and identified as a bacterium belonging to the genus of Brevibacillus based on colony morphology and 16S rDNA phylogenetic analysis.

Mutations in surface-sensing receptor WspA lock the Wsp signal transduction system into a constitutively active state.

Pseudomonas aeruginosa rugose small-colony variants (RSCVs) are frequently isolated from chronic infections, yet, they are rarely reported in environmental isolates. Here, during the comparative genomic analysis of two P. aeruginosa strains isolated from crude oil, we discovered a spontaneous in-frame deletion, wspA , which led to hyper-biofilm and RSCV phenotypes.

Pollutant Degrading Enzyme: Catalytic Mechanisms and Their Expanded Applications.

The treatment of environmental pollution by microorganisms and their enzymes is an innovative and socially acceptable alternative to traditional remediation approaches. Microbial biodegradation is often characterized with high efficiency as this process is catalyzed via degrading enzymes. Various naturally isolated microorganisms were demonstrated to have considerable ability to mitigate many environmental pollutants without external intervention.

Integrated Comparative Genomic Analysis and Phenotypic Profiling of Isolates From Crude Oil.

is an environmental microorganism that can thrive in diverse ecological niches including plants, animals, water, soil, and crude oil. It also one of the microorganism widely used in tertiary recovery of crude oil and bioremediation. However, the genomic information regarding the mechanisms of survival and adapation of this bacterium in crude oil is still limited.

A molecular mechanism for how sigma factor AlgT and transcriptional regulator AmrZ inhibit twitching motility in Pseudomonas aeruginosa.

Pseudomonas aeruginosa isolates from cystic fibrosis patients are often mucoid (due to the overexpression of exopolysaccharide alginate) yet lost motility. It remains unclear about how P. aeruginosa coordinately regulates alginate production and the type IV pili-driven twitching motility.

Evaluation and characterization of the predicted diguanylate cyclase-encoding genes in Pseudomonas aeruginosa.

Opportunistic pathogen Pseudomonas aeruginosa can cause acute and chronic infections in humans. It is notorious for its resistance to antibiotics due to the formation of biofilms. Cyclic-di-GMP is a bacterial second messenger that plays important roles during biofilm development.