Sugar esters are bioactive compounds derived from renewable resources. They consist of a sugar moiety with attached non-polar part – usually a fatty acid. These compounds find uses in cosmetic, food and pharmaceutical industries as surfactants due to their physicochemical and antimicrobial activities. In this study we have produced fatty acids for sugar ester synthesis from bacterially derived polyesters, namely polyhydroxyalkanoates (PHAs). We have developed methodology to decorate PHA monomers with a fluorinated moiety. With aid of biocatalysis a series of glucose esters was created with unmodified and modified PHA monomers. All synthesised compounds showed moderate antimicrobial activity.

Antibiotics are emerging pollutants of great concern, due to detrimental effects of their sublethal concentrations on microbial communities. Monitoring of antibiotics’ presence and concentrations in the aquatic environment is of fundamental importance to the management of water resources. This study was aimed at filling the knowledge gap in terms of presence and concentration of antibiotics in surface water and groundwater in one of the mountain regions in southern Poland. The detailed aims included the assessment of whether there are spatial and/or temporal trends in antibiotic occurrence in water and the investigation of causes behind the changes in antibiotic concentrations. The study was conducted in seven sites (two groundwater and five river water) along the Białka river valley. Antibiotics were subjected to solid-phase extraction, followed by UHPLC/MS detection. Clindamycin, erythromycin, ofloxacin and trimethoprim were the most frequently detected, while the highest concentrations were observed for oxytetracycline and clindamycin. No antibiotics were detected in only one of the groundwater sites. Sewage treatment plant effluent was the hotspot of antibiotic contamination of the river downstream. The detection rates of antibiotics in the examined region seem to be driven mainly by the stability of antibiotics in the environment.

Zobellella denitrificans MW1 is a halotolerant, facultatively anaerobic bacterium with high poly(3-hydroxybutyrate) (PHB) productivity that lacked a complete genome sequence. Here we report its first complete circular genome (4.10 Mb, 63.6% GC), obtained by hybrid Illumina-Nanopore assembly, with multi-scale cultivation data. The genome encodes a conserved phaCAB operon, multiple sucrose uptake and catabolic systems, and a canonical Pho regulon with polyphosphate metabolism genes (ppk, ppx). Ten CRISPR arrays, an intact prophage and no acquired multidrug resistance determinants were identified. Carbohydrate utilization was broad yet selective: sucrose, glucose and fructose supported the highest biomass, sucrose yielding up to 76% PHB of cell dry weight (CDW) in flasks; sucrose-rich beet molasses sustained PHB accumulation in flasks and 5 L bioreactors. In single, non-replicated fed-batch runs, a high-phosphate process reached 23 g L⁻¹ CDW with minimal PHB, whereas a low-phosphate process reached 53 g L⁻¹ CDW with 78% PHB. Because each regime was run once, these data are observations rather than a statistically supported comparison. They suggest that phosphate availability may be an important variable governing the growth-versus-storage balance, and that sucrose-rich industrial side-streams can be converted into PHB. The genomic co-occurrence of the Pho regulon, polyphosphate metabolism and phaCAB offers a hypothesis that remains to be tested by expression, enzyme-activity and targeted genetic experiments. Overall, MW1 is established as a genomically resolved platform for PHB production from low-cost, sucrose-rich feedstocks under saline conditions.