## 4 Discussion
Nevertheless, traditional medicine utilizes infusions of young raspberry shoots to treat flu-like infections [96]. Studies on the composition of methanol extracts from raspberry shoots, conducted by [PERSON] et al., indicate the presence of various phenolic compounds, including ellagic acid and other polyphenols. Inhibitory effects were also observed against _Bacillus subtilis_, _Clostridium sporogenes_, _Staphylococcus epidermidis_, _Neisseria meningitidis_, _Moraxella catararhalis_, and _Helicobacter pylori_[61]. Our studies also confirm the presence of antibacterial activity in raspberry extracts, with the strongest effect observed against _P. aeruginosa_ and the weakest against _S. marcescens_. The previously mentioned ellagic and gallic acids were also identified in the tested raspberry shoot extract, at 0.38% and 0.56% TIC, respectively. These polyphenols exhibit antibacterial properties, as demonstrated in studies conducted on animal models [97]. The presence of quinic acid (1.73% TIC in our study) may also promote the antibacterial effect, particularly against _Klebsiella_ spp. and _P. aeruginosa_[98]. The use of tea waste, specifically tea leaves, to produce extracts with confirmed antimicrobial properties aligns with sustainable resource management and zero-waste policies. The health benefits of green tea are well-documented and have been utilized for centuries in traditional medicinal practices [99]. Our studies demonstrated the antimicrobial activity of green tea extract on all tested pathogens, with the strongest activity against _P. aeruginosa_ and _E. faecalis_. Research by [PERSON] et al. also highlighted the efficacy of tea extracts on a broad spectrum of bacteria, including skin pathogens (or pathobionts) such as _S. epidermidis_, _Micrococcus luteus_, _Brebibacterium linens_, _P. fluorescens_, and _B. subtilis_[100]. Studies have also confirmed that tea extracts exhibit antibacterial activity against resistant and multidrug-resistant strains, highlighting their potential for future use [101]. One of the key bioactive compounds in green tea extracts is epigallocatechin gallate (EGCG), a predominant catechin known for its strong antibacterial properties, accounting for 1.15% of the total ion current (TIC) in our study. Previous research has also demonstrated that the bioactive compounds in green tea extracts exhibit antimicrobial activity against _E. coli_ and bacteria from the _Salmonella_ genus [102]. Tree bark is a rich source of substances used in the treatment of diseases and the direct combat of pathogens [103]. Studies on tree bark extracts traditionally used by First Nations in North America have demonstrated that 86% of the extracts exhibited activity against methicillin-sensitive _S. aureus_, 71% against _Bacillus subtilis_, and 79% against _Mycobacterium phlei_[104]. Our study demonstrated the effectiveness of extracts from birch, oak, and willow bark against six distinct opportunistic pathogens. This finding is consistent with existing literature, which reports that bark extracts are effective against a variety of bacteria, including _Escherichia coli_ and _Pseudomonas aeruginosa_[105; 106]. The antimicrobial properties of oak bark extracts are primarily attributed to the presence of phenolic compounds, such as gallic and ellagic acids, which exhibit both bacteriostatic and bactericidal activity [43; 107]. Our studies did not confirm antibacterial activity for _Quercus super_ bark, contrary to the findings of [PERSON] et al., who demonstrated antibacterial activity against _S. aureus_ and _E. coli_[108]. In our studies, we utilized expanded cork, a material produced by exposing cork to high temperatures (typically around 180-200 \({}^{\circ}\)C) during its manufacturing process. This thermal treatment could have significantly altered the chemical composition of the cork bark, potentially leading to the degradation or volatilization of thermolabile bioactive compounds responsible for the antimicrobial properties. As for the antibacterial effect of _B.