## 4 Discussion
Increased lipid production has also been observed in the case of \(N\)-(dodecyloxycarboxymethyl)-\(N\),\(N\),\(N\)-trimethyl ammonium chloride in _Saccharomyces cerevisiae_ cells [28]. Research by [PERSON] et al. [15], describing yeast treated with gemini surfactant 3,3'-(2,7-dioxactane)-bis(1-decylpyridinium bromide) (3 DOBP-4,10) at a concentration of 6 uM, showed that the internal cell organelles were destroyed but the cell wall structure was preserved. In our study, TEM studies revealed that the cell walls of mycelia treated with C6 at a concentration of 0.155 mM had partly loosestructures, especially in the apical part. Deformations in the apical parts of hypha are due to the nature of mold growth. Hyphal growth is apical, with continuous increases and extensions in the cell wall and membrane at the hyphal tip, where the cell wall is thin and therefore more sensitive to external factors. After treatment with cationic gemini surfactant at higher concentrations, the cell wall was distended but preserved its integrity. Similar results were reported by [PERSON] et al. [35], who studied the effect of the biocide Akacid(r) plus (Ch. 1007; POC, Vienna, Austria); composed of a mixture of two different polymeric guanidine compounds on _Aspergillus parasiticus_. No damage was observed to the cell wall, but similar to treatment with compound C6, destruction of the plasma membrane was noted. Changes in the endo-membrane system (plasma membrane and membranous organelles) were noted by [PERSON] et al. [36] in their study of the effects of wild chamomile flower oil on the ultrastructure of _A. niger_. However, these authors also observed extensive changes in the cell wall, which was not broken down by the plant oil but did lose its integrity. [PERSON] et al. conducted research on _A. brasiliensis_ strain ATCC 16404 [4]. In their work regarding the antifungal activity of citronella oil, they observed slightly different changes in the mycelium ultrastructure compared with those reported here following treatment with gemini surfactants. These differences mainly concerned the cell wall, which was destroyed after the action of citronella oil. Microscopic analysis showed extensive vacuolation with vacuole fusion in the hyphae. If we compare the actions of these antifungal agents--chamomile and citronella oil, Akacid(r) plus and gemini surfactant C6--it can be concluded on the basis of TEM analysis that gemini surfactants at concentrations of 0.155-0.62 mM produce larger cell defects. Only membranous structures, multivesicular bodies, and electron dense granules are present in the cells. Many authors indicated that the way in which disinfectants work especially on molds have not yet been fully investigated; therefore, these phenomena are not fully understood and explained [37; 38]. The activity of modern antifungal biocides has been the subject of few works. Determining the effectiveness of gemini surfactants and understanding the areas of their action in the cell, revealing what causes its destruction is an important issue. In order to use them as antifungal agents, the research proposed in this study, as well as in a previous article [16], are needed. The revised results suggest that cationic gemini surfactants could have a wide range of practical applications as active compounds in disinfection.