Dark homogenous fungal-based layers called biofinishes and vegetable oils are keyingredients of an innovative wood protecting system. The aim of this study was todetermine which of the vegetable oils that have been used to generate biofinishes onwood will provide carbon and energy for the biofinish-inhabiting fungus Aureobasidiummelanogenum, and to determine the effect of the oil type and the amount of oil on thecell yield. Aureobasidium melanogenum was cultivated in shake flasks with differenttypes and amounts of carbon-based nutrients. Oil-related total cell and colony-formingunit growth were demonstrated in suspensions with initially 1% raw linseed,stand linseed, and olive oil. Oil-related cell growth was also demonstrated with rawlinseed oil, using an initial amount of 0.02% and an oil addition during cultivation. Nilered staining showed the accumulation of fatty acids inside cells grown in the presenceof oil. In conclusion, each tested vegetable oil was used as carbon and energysource by A. melanogenum. The results indicated that stand linseed oil provides lesscarbon and energy than olive and raw linseed oil. This research is a fundamental stepin unraveling the effects of vegetable oils on biofinish formation.
MULTIFILE
Five methods were compared to determine the best technique for accurate identification of coagulase-negative staphylococci (CoNS) (n=142 strains). MALDI-TOF MS showed the best results for rapid and accurate CoNS differentiation (correct identity in 99.3%). An alternative to this approach could be Vitek2 combined with partial tuf gene sequencing.
Plasmid-mediated dissemination of antibiotic resistance among fecal Enterobacteriaceae in natural ecosystems may contribute to the persistence of antibiotic resistance genes in anthropogenically impacted environments. Plasmid transfer frequencies measured under laboratory conditions might lead to overestimation of plasmid transfer potential in natural ecosystems. This study assessed differences in the conjugative transfer of an IncP-1 (pKJK5) plasmid to three natural Escherichia coli strains carrying extended-spectrum beta-lactamases, by filter mating. Matings were performed under optimal laboratory conditions (rich LB medium and 37°C) and environmentally relevant temperatures (25, 15 and 9°C) or nutrient regimes mimicking environmental conditions and limitations (synthetic wastewater and soil extract). Under optimal nutrient conditions and temperature, two recipients yielded high transfer frequencies (5 × 10–1) while the conjugation frequency of the third strain was 1000-fold lower. Decreasing mating temperatures to psychrophilic ranges led to lower transfer frequencies, albeit all three strains conjugated under all the tested temperatures. Low nutritive media caused significant decreases in transconjugants (−3 logs for synthetic wastewater; −6 logs for soil extract), where only one of the strains was able to produce detectable transconjugants. Collectively, this study highlights that despite less-than-optimal conditions, fecal organisms may transfer plasmids in the environment, but the transfer of pKJK5 between microorganisms is limited mainly by low nutrient conditions.
MULTIFILE
To treat microbial infections, antibiotics are life-saving but the increasing antimicrobial resistance is a World-wide problem. Therefore, there is a great need for novel antimicrobial substances. Fruit and flower anthocyanins have been recognized as promising alternatives to traditional antibiotics. How-ever, for future application as innovative alternative antibiotics, the full potential of anthocyanins should be further investigated. The antimicrobial potential of anthocyanin mixtures against different bacterial species has been demonstrated in literature. Preliminary experiments performed by our laboratories, using grape, rose and red cabbage anthocyanins against S. aureus and E. coli confirmed the antimicrobial potential of these substances. Hundreds of different anthocyanin entities have been described. However, which of these entities hold antimicrobial effects is currently unknown. Our preliminary data show that an-thocyanins extracted from grape, rose and red cabbage contain different collections of anthocyanin entities with differential antimicrobial efficacies. Our focus is on the extraction and characterization of anthocyanins from various crop residues. Grape peels are residues in the production of wine, while red rose and tulip leaves are residues in the production of tulip bulbs and regular horticulture. The presence of high-grade substances for pharmacological purposes in these crops may provide an innovative strategy to add value to other-wise invaluable crop residues. This project will be performed by the collaborative effort of our institute together with the Medi-cal Microbiology department of the University Medical Center Groningen (UMCG), 'Wijnstaete', a small-scale wine-producer (Lemelerveld) and Imenz Bioengineering (Groningen), a company that develops processes to improve the production of biobased chemicals from waste products. Within this project, we will focus on the antimicrobial efficacy of anthocyanin-mixtures from sources that are abundantly and locally available as a residual waste product. The project is part of a larger re-search effect to further characterize, modify and study the antimicrobial effects of specific anthocy-anin entities.
What if living organisms communicated signals from the environment to us and thereby offered a sustainable alternative to electronic sensors? Within the field of biodesign, designers and scientists are collaborating with living organisms to produce new materials with ecological benefits. The company Hoekmine, in collaboration with designers, has been researching the potential of flavobacteria for producing sustainable colorants to be applied on everyday products. These non-harmful bacteria can change their form, texture and iridescent color in response to diverse environmental factors, such as humidity and temperature. Here, billions of cells are sensing and integrating the results as color. Therefore, Hoekmine envisions biosensors, which would minimize the use of increasingly demanded electronic sensors, and thus, the implementation of scarce and toxic materials. Developing a living sensor by hosting flavobacteria in a biobased and biodegradable flexible material offers opportunities for sustainable alternatives to electronic sensors. Aiming to take this concept to the next level, we propose a research collaboration between Avans, Hoekmine and a company specialized in biobased and biodegradable labels, Bio4Life. Together with this interdisciplinary team, we aim to bridge microbiology and embodiment design, and contribute to the development of a circular economy where digital technology and organic systems merge in the design of Living Circular Labels (LCLs). Throughout the project we will use an iterative approach between designing and testing LCLs that host living flavobacteria and additionally, methods for the end user to activate the bacteria’s growth at a given time.
Antimicrobial Resistance (AMR), the ability of micro-organisms to resist antibiotics, is associated with ~4.9 million deaths globally, reported in 2022. In the EU alone, more than 35.000 people die from antimicrobial-resistant infections annually, resulting in loss of life as well as €1.5Bn/year in healthcare costs and productivity losses. Rapid diagnostics tests are needed, current testing takes between 24 hours to a few days (for slow growing microorganisms), delaying patient treatment and severely impacting treatment outcomes. SoundCell BV have developed a technique (TRL5), for real-time detection of bacteria's viability in the presence of antibiotics. Nano-mechanical vibration of an ultrathin graphene sheet correlates to viability of bacteria immobilized on this sheet. Bacterial motion is transferred to this sheet, and movement of this sheet is tracked via a high-speed laser. Living bacteria produce a strong signal, which diminishes when antibiotics kill them. Unaffected by growth rates, results are achieved in one hour with this technique. This technology opens up possibility for rapid diagnostics of antibiotic resistance in patients with infections of slow growing pathogens (such as mycobacteria and yeast). In such cases the time to result is slowest, significantly delaying effective patient treatment. We aim to validate this technique in our clinical microbiology laboratory.
