Olga Marchut-Mikołajczyk

Endophytic bacteria are key components of plant microbiomes, enhancing host growth, stress tolerance, and defence mechanisms. Ten cultivable strains affiliated with Bacillaceae, including putative novel Priestia and Bacillus species, were previously isolated from Galium aparine L.'s tissues. All tolerated diverse levels of abiotic stresses, produced ammonia and auxins, as well as all exhibited strong hydrolytic enzyme activities (amylase, protease, xylanase, and pectinase), indicating robust metabolic versatility. These bacteria stand out as prolific producers of industrially relevant compounds. Priestia megaterium GR4 demonstrated high production of hydrolytic enzymes and biosurfactants, and most strains synthesized and accumulated polyhydroxyalkanoates (PHA), highlighting their potential as sustainable bioplastic producers. UPLC‐MS/MS confirmed koranimine production by Peribacillus frigoritolerans GR2. Previous genome mining studies revealed diverse biosynthetic gene clusters, including those for surfactin and fengycin. Overall, G. aparine endophytes represent powerful biological factories capable of producing a wide range of valuable compounds, including enzymes, biosurfactants and biopolymers, with strong potential for applications in industrial biotechnology, sustainable agriculture, and biocontrol.

Chitosan-based materials are widely investigated as sustainable adsorbents for environmental remediation due to their biodegradability, abundance, and functional versatility. This review summarises recent advances (2015–2025) in the use of chitosan and its derivatives for the removal of organic and inorganic pollutants from aqueous systems. The correlation of material structure, modification strategies, and removal efficiency are discussed, focusing on adsorption, chelation, and flocculation mechanisms. Special attention is given to hybrid and bio-integrated systems that enhance treatment efficiency through synergistic effects. Key challenges, such as limited stability, reduced performance in complex matrices, and scalability barriers, are critically evaluated. Regeneration, reusability, and life-cycle considerations are also addressed. The findings highlight the need for more application-oriented and system-level methods in future research by highlighting both the promise and present limits of chitosan-based materials. The findings indicate that chitosan-based materials demonstrate both potential and existing limitations. Future investigations should concentrate on application- and system-level approaches.

Background: Plants can thrive in changing environmental conditions with the help of microorganisms that inhabit their tissues, known as endophytes. However, many endophytes do not grow under standard laboratory conditions, but metagenomic analysis provides insights into microbial diversity and community structure. This study aimed to compare communities of endophytic bacteria from stinging nettle ( Urtica dioica L.) isolated throughout different regions of Poland, both culturable and non-culturable, and to identify shared bacterial taxa across all locations, which may represent a putative core microbiome. Results: From all regions, 66 bacterial isolates were obtained. 32% of them were identified, mostly as Bacillus and Pseudomonas members, which are common endophytes of many plants. Although a substantial proportion of reads remained unclassified, metagenomic data enabled the tentative identification of several genera present across all samples, including Acinetobacter , Bacillus , Citrobacter , Enterococcus , Escherichia , Klebsiella , Paenibacillus , Salmonella , Vibrio , and Xanthomonas . Among the isolates, Exiguobacterium sp. SP2-R3 exhibited the most intense orange pigmentation. The results indicate that the pigment is putatively quinone-like and demonstrates promising scavenging activity. Conclusions: The study deepens our understanding of U. dioica L. endophytic communities and highlights the value of combining cultivation-based methods with metagenomic approaches. Also, among the isolates with visible potential to produce pigments, the best producer was selected and identified. It is recognized that those isolates may possess additional valuable properties that warrant deeper investigation.

Microbial pigment production is often a physiological response to environmental stress, including salinity, oxidative stress, and nutrient limitation. In this study, we investigated Aspergillus tubingensis FF14, a filamentous fungus isolated from naturally salinized coastal soil, periodically penetrated by seawater. This strain produced a distinctive orange intracellular pigment, which was identified via ultra-high-performance liquid chromatography coupled to diode array detection and electrospray ionization mass spectrometry as a mixture of three xanthophylls: violaxanthin, antheraxanthin, and neoxanthin. To date, this is the first documented case of xanthophyll biosynthesis in an Aspergillus species. Additionally, the antioxidant potential of the extracted pigment mixture was evaluated. Optimization experiments revealed that maximal pigment yield occurred at pH 3, 30°C, with 5% (vol/vol) sodium chloride, and 30% malt extract medium volume. Genome sequencing and annotation revealed biosynthetic gene clusters with domains characteristic of lycopene cyclase and phytoene synthase, indicating involvement in early steps of C40 carotenoid biosynthesis. Although biosynthetic gene clusters that are potentially linked to carotenoid biosynthesis were identified, the specific mechanisms responsible for xanthophyll biosynthesis in A. tubingensis FF14 remain to be elucidated. These findings provide new insights into fungal carotenoid metabolism and demonstrate the potential of A. tubingensis FF14 as a sustainable source of carotenoid pigments. IMPORTANCE: Microorganisms living in extreme environments frequently produce compounds with protective value against environmental stressors. Although these natural products have potential practical value, many remain undiscovered. We identified a halophilic fungus, Aspergillus tubingensis FF14, isolated from saline soil that produces bright orange pigments belonging to the xanthophyll family, a group of carotenoids with antioxidant potential. This is the first report on xanthophyll production in this genus. We showed that salt stress enhanced pigment production and optimized culture conditions to increase pigment yield. Genome analysis identified the genes that are most likely responsible for carotenoid biosynthesis, linking metabolite production with genetic potential. These findings expand current knowledge of fungal metabolites and demonstrate that extremophilic fungi may be promising and sustainable sources of valuable natural pigments.

Environmental pollution resulting from heavy metals constitutes a critical global issue. Remediation technologies offer potential solutions, particularly t

Lipopeptides, are emerging as sustainable alternatives to synthetic surfactants due to their biodegradability, low toxicity, and broad application in biore

This study investigated agricultural saline soils collected from distinct pedoclimatic profiles from Poland and Italy. Twelve fungal strains from Italy and 9 from Poland were identified and tested for halotolerance, extracellular enzyme production, biosurfactant potential, and mycotoxin production. The tested strains were affiliated to 8 genera, with Aspergillus and Penicillium being the most predominant. All tested strains were confirmed to be good producers of at least one of the analyzed hydrolytic enzymes, with cellulase being the most frequently produced. Notably, Ramularia mali FF1 was the best producer of the tested extracellular enzymes and showed the highest enzymatic activity for amylase, cellulase, chitosanase, pectinase and xylanase among all strains. A hemolytic assay was implemented to evaluate the potential for biosurfactant production in media supplemented with various sodium chloride concentrations. Among 21 tested strains, 14 demonstrated hemolytic activity at 5% NaCl. Based on the results, Acremonium sclerotigenum FF3 was selected to perform biosurfactant analysis. Mycotoxin screening revealed that Penicillium canescens S10 was the only producer of any examined mycotoxin, with 5.759 μg/mL concentration of ochratoxin A. This research underscores the varied enzymatic and biosurfactant capabilities of halophilic fungi adapted to saline soils and highlight the biotechnological potential of these organisms and environments.

The poultry industry produces significant quantities of keratin-rich waste, primarily feathers, whose traditional disposal methods—incineration or chemical treatment—result in environmental damage and resource depletion. This research introduces a sustainable biotechnological method for the valorization of feather waste utilizing Gordonia alkanivorans S7, an actinomycete strain extracted from petroleum plant sludge. This is the inaugural publication illustrating keratinolytic activity in the Gordonia genus. The optimization of the degradation process via the Taguchi approach led to the effective biodegradation of untreated home chicken feathers, achieving dry mass loss of up to 99% after 168 h in a mineral medium. The agricultural potential of the obtained keratin hydrolysate, which was high in organic components (C 31.2%, N 8.9%, H 5.1%, and S 1.7%), was assessed. Phytotoxicity tests demonstrated that the feather hydrolysate led to better growth of the indicator plants—Sorghum saccharatum and Lepidium sativum. The highest values of root growth stimulation were 26% for S. saccharatum and 31% for L. sativum, at a dose of 0.01%. Shoot growth stimulation was noted only for L. sativum, reaching 38% (0.01%), 53% (0.05%), and 37% (0.1%), as compared to the control sample. These results demonstrate the process’s combined economic and environmental benefits, providing a fresh approach to the production of bio-based plant biostimulants and sustainable keratin waste management.

The increasing environmental issue related to textile waste, especially synthetic fibers treated with acrylic resins, demands the creation of sustainable recycling techniques. Biotechnological methods, such as microbial degradation, present a viable solution for the elimination of these coatings and the recovery of important fibers. This study investigates the potential of a biotechnological approach for the removal of acrylic resins from coated woven textile wastes. The biodegradation process of coated woven fabric after the pretreatment at a high temperature (121 °C) or 6% H₂O₂ was performed using the hydrocarbon-degrading bacterial strain Gordonia alkanivorans S7. Over a 72 h biodegradation period, an increase in emulsifying and esterase activities was observed. A reduction mass of the coated textile waste by up to 7 wt% was achieved, and the elimination of acrylic resin was confirmed through FTIR analysis. The findings indicate the usefulness of the biotechnological method in eliminating acrylic resin from textile waste, presenting a viable strategy for polyester fiber recovery and substantially mitigating its environmental impact.