Propolis is a multi-functional bee product rich in polyphenols. In this study, the inhibitory effect of Anatolian propolis against SARS-coronavirus-2 (SARS-CoV-2) was investigated in vitro and in silico. Raw and commercial propolis samples were used, and both samples were found to be rich in caffeic acid, p-coumaric acid, ferulic acid, t-cinnamic acid, hesperetin, chrysin, pinocembrin, and caffeic acid phenethyl ester (CAPE) at HPLC-UV analysis. Ethanolic propolis extracts (EPE) were used in the ELISA screening test against the spike S1 protein (SARS-CoV-2): ACE-2 interaction for in vitro study. The binding energy values of these polyphenols to the SARS-CoV-2 spike and ACE-2 protein were calculated separately with a molecular docking study using the AutoDock 4.2.6 program. In addition, the pharmacokinetics and drug-likeness properties of these eight polyphenols were calculated according to the SwissADME tool. The binding energy value of pinocembrin was highest in both receptors, followed by chrysin, CAPE, and hesperetin. Based on the in silico modeling and ADME (absorption, distribution, metabolism, and excretion) behaviors of the eight polyphenols, the compounds exhibited the potential ability to act effectively as novel drugs. The findings of both studies showed that propolis has a high inhibitory potential against the Covid-19 virus. However, further studies are now needed.

A polyethylene terephthalate (PET)-degrading bacterium identified as Stenotrophomonas maltophilia PRS8 was isolated from the soil of a landfill. The degradation of the PET bottle flakes and the PET prepared as a powder were assessed using live cells, an extracellular medium, or a purified cutinase-like enzyme. These treated polymers were analyzed using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The depolymerization products, identified using HPLC and LC-MS, were terephthalic acid (TPA), mono(2-hydroxyethyl)-TPA (MHET), and bis(2-hydroxyethyl)-TPA (BHET). Several physicochemical factors were optimized for a better cutinase-like enzyme production by using unique single-factor and multi-factor statistical models (the Plackett–Burman design and the central composite design software). The enzyme was purified for homogeneity through column chromatography using Sephadex G-100 resin. The molecular weight of the enzyme was approximately 58 kDa. The specific activity on para nitrophenyl butyrate was estimated at 450.58 U/mg, with a purification of 6.39 times and a yield of 48.64%. The enzyme was stable at various temperatures (30–40 °C) and pH levels (8.0–10.0). The enzyme activity was significantly improved by the surfactants (Triton X-100 and Tween-40), organic solvent (formaldehyde), and metals (NiCl₂ and Na₂SO₄). The extracellular medium containing the cutinase-type enzyme showed a depolymerization yield of the PET powder comparable to that of Idonella skaiensis IsPETase and significantly higher than that of Humicola insolens thermostable HiCut (HiC) cutinase. This study suggests that S. maltophilia PRS8 is able to degrade PET at a mesophilic temperature and could be further explored for the sustainable management of plastic waste.

A Gram-staining-negative, catalase- and oxidase-positive, strictly aerobic, rod-shaped bacterial strain isolated from fresh water in Trabzon, Turkey and designated MK3^T was characterized by phenotypic and molecular methods in order to determine its phylogenetic position. On the basis of 16S rRNA gene sequence similarity, strain MK3^T was shown to belong to the genus Flavobacterium , being most closely related to Flavobacterium ceti CECT 7184^T (93.6 %). Sequence similarity with other species of the genus Flavobacterium with validly published names was less than 91.6 %. Phenotypic and chemotaxonomic data supported the affiliation of strain MK3^T to the genus Flavobacterium . The only menaquinone was MK-6; the major fatty acids were iso-C_15 : 0 (45.2 %), summed feature 9 (C_16 : 0 10-methyl and/or iso-C_17 : 1ω9c; 20.4 %) and summed feature 3 (C_16 : 1ω7c and/or C_16 : 1ω6c; 13.3 %) and the major polar lipids were phosphatidylethanolamine, one unidentified aminophospholipid and two unidentified phospholipids. The G+C content of the genomic DNA was 38.6 mol%. The results of physiological and biochemical tests allowed strain MK3^T to be distinguished phenotypically from Flavobacterium ceti CECT 7184^T. Strain MK3^T, therefore, represents a novel species of the genus Flavobacterium , for which the name Flavobacterium anatoliense sp. nov. is proposed. The type strain is MK3^T ( = LMG 26441^T = NCCB 100384^T). An emended description of Flavobacterium ceti is also proposed.