For decades, researchers have focused on containing terrestrial oil pollution. The heterogeneity of soils, with immense microbial diversity, inspires them to transform pollutants and find cost-effective bioremediation methods. In this study, the mycoremediation potentials of five filamentous fungi isolated from polluted soils in Kazakhstan were investigated for their degradability of n-alkanes and branched-chain alkanes as sole carbon and energy sources. Dry weight estimation and gas chromatography–mass spectrometry (GC-MS) monitored the growth and the changes in the metabolic profile during degradation, respectively. Penicillium javanicum SBUG-M1741 and SBUG-M1742 oxidized medium-chain alkanes almost completely through mono- and di-terminal degradation. Pristane degradation by P. javanicum SBUG-M1741 was >95%, while its degradation with Purpureocillium lilacinum SBUG-M1751 was >90%. P. lilacinum SBUG-M1751 also exhibited the visible degradation potential of tetradecane and phytane, whereby in the transformation of phytane, both the mono- and di-terminal degradation pathways as well as α- and ß-oxidation steps could be described. Scedosporium boydii SBUG-M1749 used both mono- and di-terminal degradation pathways for n-alkanes, but with poor growth. Degradation of pristane by Fusarium oxysporum SBUG-M1747 followed the di-terminal oxidation mechanism, resulting in one dicarboxylic acid. These findings highlight the role of filamentous fungi in containing oil pollution and suggest possible degradation pathways.

Isolated enzymes or whole microbial cells are environmentally friendly catalysts which can be used in aqueous solution at room temperature, atmospheric pressure, and moderate pH values and are therefore well suited for the green synthesis of novel drugs. Microbial enzymes transform numerous substances in a reaction-, region-, and stereospecific way and thus in many cases may meet the requirements of modern drug synthesis. Of particular practical value is the fact that they not only catalyze the reactions of their natural substrates but also convert other compounds. Biotechnological processes use whole cells and/or specific enzymes. Biosynthetic processes, which often require a cascade of individual enzyme reactions, are usually carried out with whole cells, whereas biotransformation reactions use either isolated enzymes or whole cells depending on the properties of the enzymes involved. When evaluating a process, the advantages and disadvantages of isolated enzymes and whole cells must be weighed against each other, though where possible, specific enzymes tend to be preferred so as to exclude side reactions catalyzed by cells. This Special Issue will provide an insight into strategies of biosynthesis and biotransformation of novel drugs. The latest proven enzyme-mediated routes, using single-step biotransformation or enzyme cascade synthesis, will be discussed.

Antibiotic-metal complexes attract the attention of pharmaceutical scientists who endeavor to increase the activity of antibiotics currently in use as those looking for new compounds possessing modified pharmacological and toxicological properties. This research proposed enhanced antimicrobial and cytotoxic activities of metronidazole and reduced irritancy of zinc chloride through complexation. The chemically green preparation of metronidazole: zinc (ІІ) complexes with different ratios: (A; 2:1), (B; 1:1) and (C; 1:2), revealed the formation of three complexes. The differences between their structures, physical and chemical properties were evaluated using morphological characteristics, DSC, XRD, FTIR, Mass spectrometry, and UV–Vis spectroscopy. The antimicrobial activities of the complexes were increased when compared to the parent drug where complex-C manifested the highest antibacterial activity (MIC = 0.625 mM and 10 mM for the bacterial strains and C. albicans, respectively). The antitumor efficacy of the complexes was studied against HepG2 and MCF-7 human cancer cell lines. Complex-A showed the highest cytotoxicity against HepG2 cells (IC₅₀ = 17.2 μM), while, complex-C displayed the most cytotoxic activity against MCF-7 cells (IC₅₀ = 29.0 μM). The in vivo skin irritancy study of the complexes on rats and their histological examination were assessed and showed no erythema and/or edema. Our results suggest the promising antimicrobial and antitumor activity of the prepared metronidazole-zinc complexes.