Birch Tar Introduced into Polylactide and Its Influence on the Barrier, Thermal, Functional and Biological Properties of the Film Obtained by Industrial Extrusion

Characterization of bacterial biofilms developed on the biodegradable polylactide and polycaprolactone polymers containing birch tar in an aquatic environment

Birch tar was added to polylactide (PLA) and polycaprolactone (PCL) to create films with antimicrobial properties. After incubating the films for seven days in lake water, the diversity of bacterial communities developed on the surfaces of PCL and PLA with embedded birch tar (1 %, 5 %, and 10 %, w/w) was assessed with amplicon sequencing of the 16S rRNA gene on a MiSeq platform (Illumina). Notably, Aquabacterium and Caulobacter were more abundant at the surface of PCL compared to PLA (13.4 % vs 0.2 %, p < 0.001 and 9.5 % vs 0.2 %, p < 0.001, respectively) while Hydrogenophaga was significantly more abundant at the surface of PLA compared to PCL (6.1 % vs 1.8 %, p < 0.01). Overall, lower birch tar concentrations (1 % and 5 % on both polymers) stimulated bacterial diversity in biofilms compared to the control. The number of reeds assigned to Flavobacterium and Aquabacterium showed a rising trend with the increase of birch tar concentration on the surface of both polymers.

Assessing Antimicrobial Efficacy on Plastics and Other Non-Porous Surfaces: A Closer Look at Studies Using the ISO 22196:2011 Standard

The survival and spread of foodborne and nosocomial-associated bacteria through high-touch surfaces or contamination-prone sites, in either healthcare, domestic or food industry settings, are not always prevented by the employment of sanitary hygiene protocols. Antimicrobial surface coatings have emerged as a solution to eradicate pathogenic bacteria and prevent future infections and even outbreaks. Standardised antimicrobial testing methods play a crucial role in validating the effectiveness of these materials and enabling their application in real-life settings, providing reliable results that allow for comparison between antimicrobial surfaces while assuring end-use product safety. This review provides an insight into the studies using ISO 22196, which is considered the gold standard for antimicrobial surface coatings and examines the current state of the art in antimicrobial testing methods. It primarily focuses on identifying pitfalls and how even small variations in methods can lead to different results, affecting the assessment of the antimicrobial activity of a particular product.

Polycaprolactone-Based Films Incorporated with Birch Tar-Thermal, Physicochemical, Antibacterial, and Biodegradable Properties

We present new polymer materials consisting of polycaprolactone (PCL), polyethylene glycol (PEG), and birch tar (D). PEG was introduced into the polymer matrix in order to obtain a plasticizing effect, while tar was added to obtain antibacterial properties and to change the physicochemical properties of the film. The materials were obtained by the solvent method and characterized using a variety of methods to test their performance and susceptibility to biodegradation. The obtained data indicate that the introduction of the bioactive substance (D) into PCL improved the thermal stability and significantly lowered the Young's modulus values of the tested polymers. Moreover, the addition of birch tar improved the barrier and bacteriostatic properties, resulting in a reduction in the growth of pathogenic bacteria on the surface of the film. The films are not mutagenic but are susceptible to biodegradation in various environments. Due to their properties, they have potential for application in agriculture and horticulture and for packaging food, mainly vegetables grown in the field.

Effect of birch tar embedded in polylactide on its biodegradation

The plasticized film was made of polylactide and birch tar, which was used in a concentration of 1, 5 and 10 % by weight. Tar was added to the polymer to obtain materials with antimicrobial properties. The main purpose of this work is to characterize and biodegradation of this film after the end of its use. Therefore, the following analyzes were performed: enzymatic activity of microorganisms in the presence of polylactide (PLA) film containing birch tar (BT), biodegradation process in compost, barrier changes and structural properties of the film before and after biodegradation and bioaugmentation. Biological oxygen demand BOD21, water vapor permeability (Pv), oxygen permeability (Po), scanning electron microscopy (SEM) and enzymatic activity of microorganisms were assessed. Microorganism strains Bacillus toyonensis AK2 and Bacillus albus AK3 were isolated and identified, which constituted an effective consortium increasing the susceptibility of polylactide polymer material with tar to biodegradation in compost. Analyses with the use of the above-mentioned strains had an impact on the change of physicochemical properties, e.g. the presence of biofilm on the surface of the analyzed films and the reduction of the barrier properties of the film, which translates into the recorded susceptibility to biodegradation of these materials. The analyzed films can be used in the packaging industry, and after use, subjected to intentional biodegradation processes, including bioaugmentation.