Since they are more environmentally acceptable than their chemically synthesized counterparts, biosurfactants are used in a wide range of environmental applications. However, less research has been done on biosurfactants within the context of the circular economy, despite their theoretical potential to fulfill a number of circular economy ambitions, including closing the consumption loop, regenerating natural systems, and maintaining resource value within the system. Hence, the main objective of this review is to identify and analyze the contributions of biosurfactants to the implementation of the circular economy. A final sample of 30 papers from the Web of Science database was examined. We identified five broad categories of contributions: waste stream-derived production, combating food waste, strengthening soil health, and improving the efficiency of water resources. We concluded that, while manufacturing biosurfactants from waste streams can reduce production costs, optimizing yield remains a contentious issue that complicates the adoption of biosurfactants into the circular economy framework.

This study investigates the fabrication and characterization of polymeric nanoparticles based on polyhydroxyalkanoates (PHAs) loaded with curcumin for biomedical applications. PHAs, biodegradable and biocompatible polymers, were synthesized via bacterial fermentation and used to encapsulate curcumin using the nanoprecipitation method. The resulting nanoparticles were characterized for their particle size, polydispersity index, and encapsulation efficiency, achieving high entrapment rates (above 80%) and nanometric size distribution. Stability assessments demonstrated prolonged structural integrity under storage conditions. In vitro release studies conducted in phosphate-buffered saline at pH 5 and 7.4 revealed sustained drug release profiles. Biocompatibility and cytotoxicity assays using human astrocytes and fibroblasts confirmed the nanoparticles’ safety, while antiproliferative tests on glioblastoma and colon cancer cell lines indicated potential therapeutic efficacy. Additionally, skin irritation and corrosion tests using the EpiDerm™ model classified the formulations as non-irritant and non-corrosive. These findings suggest that PHA-based nanoparticles offer a promising nanocarrier system for curcumin delivery, with potential applications in cancer treatment and regenerative medicine. Future research should focus on optimizing the formulation and evaluating in vivo therapeutic effects.

Background: Polyhydroxyalkanoates (PHAs) are bacteria-synthesized biopolymers under imbalanced growth conditions. These biopolymers are acknowledged as potential biomaterials for future applications because of their characteristics of biocompatibility and biodegradability, and ability to be produced rapidly, and strong functionality of mechanical resistance. This article aims to perform microbial fermentation using the Pseudomonas putida strain to identify the quantity of biopolymers, particularly of the medium-chain-length (mcl-PHA) polyhydroxyalkanoates, based on the type and quantity of the added precursors (glucose and fatty acids). Methods: To understand the microbial interaction and the mechanism involved in PHA biosynthesis, several methods were employed and microbial biomass was obtained using the Pseudomonas putida strain capable of producing PHA. The polymer production by acetone extraction was analyzed using the Soxhlet method, while the biopolymer purification was done via the methanol-ethanol treatment, after which the biomass estimation was done through spectrophotometric analysis. This was followed by measuring the dry weight of the cells and quantification of the biopolymer produced using the gas chromatography method (GC). Results: The highest PHA yield was obtained using the octanoic (17 mL in 2000 mL medium) and hexanoic acids (14 mL in 2000 mL medium) as the precursors. As a result, the octanoic acid - octanoic acid, heptanoic acid – nonanoic acid, and octanoic acid - hexanoic acid were identified as the different precursors that supported the quantity of PHA obtained. Conclusion: Among the 4 types of structurally related substrates, the Pseudomonas putida ICCF 319 strain showed a preference for the C8 sublayer for the biosynthesis of the elastomeric PHAs composed predominantly of more C8 monomers than the C6 and C10.

Biomaterials represent a distinct class of materials used in various medical applications, such as replicating the shape or function of damaged tissue caused by disease or trauma. The increasing focus on polyhydroxyalkanoate (PHA) research can be attributed to their properties, such as biodegradability, biocompatibility, and bioresorbability. PHAs can be incorporated into polymeric complexes or combined with bioceramics or bioactive substances. Films of PHO-HAp-Curcumin were prepared, and optimization studies were conducted using Design-Expert software (Stat-Ease 360-Trial Version). The effects of independent variables (amount of PHO, HAp, and curcumin) on biodegradability, film thickness, and curcumin release were studied. Statistical modeling revealed significant interactions among the components, with the 2FI and quadratic models providing strong predictive accuracy. The interaction of HAp and PHO amounts (X₂X₃) has a significant effect on biodegradability (Y₁) and film thickness (Y₃). For the degree of the cumulative release of curcumin (CDR), there was no significant interaction between the independent variables (curcumin-X₁, HAp-X₂, and PHO-X₃). Optimized film exhibited a maximum desirability of 0.777 with 1 mg of curcumin, 100 mg of HAp, and 172.31 mg of PHO. A morphological analysis of optimized film revealed a rough, particle-rich surface favorable for biomedical use. The findings highlight the promise of PHO-HAp-Curcumin composite films in advancing tissue engineering.

Polyhydroxyalkanoates (PHAs) are microbial homo- and copolymers of [R]-β-hydroxyalkanoic acids, produced by a wide variety of bacteria as an intracellular carbon and energy reserve. To obtain mcl-PHAs of microbial origin, we used a Pseudomonas spp. strain (from the National Institute for Chemical-Pharmaceutical Research and Development (ICCF) culture collection of micro-organisms), by varying the carbon sources and the precursors. In this work, assays were performed with fermentation media seeded with inoculum cultures of strain Pseudomonas putida in a proportion of 10%. The influence on strain development and mcl-PHA production of carbon sources consisting in C6, C7, C8 and C9 fatty acids (as polymers precursors) was analyzed. Due to their properties, similar to conventional plastics and their biodegradability, PHAs are suitable for many applications and for biomedical materials useful in surgical sutures, tissue engineering and drugs carriers, leading us to deepen the study of obtaining micro/nanofibers by the electrospinning method.

Modern diets are high in fructans, which may lead to abdominal discomfort, particularly in sensitive individuals. Microbial inulinase, an enzyme that hydrolyzes inulin into fructose and fructo-oligosaccharides (FOS), has significant prebiotic potential and may contribute to the prevention of metabolic disorders by enhancing fructan digestion. This study investigates inulinase production by the Aspergillus niger ICCF 92 strain under various growth conditions. Three carbon sources (inulin, molasses, and carob pod decoction), the time required for biosynthesis processes, and stirring speed were evaluated for their influence on inulinase activity. Nitrogen sources included yeast extract, ammonium nitrate, and ammonium phosphate. Process monitoring included pH measurement, protein quantification via the Bradford assay, and inulinase activity assessment using the 3,5-dinitrosalicylic acid method. The highest inulinase production (38.29 U/mL) and protein concentration (0.7548 mg/mL) were achieved after 14 days of static fermentation with carob pod decoction as the carbon source.