Purification of laccase from the fungus Clitopilus prunulus BV18 and its application in bioconversion of tea polyphenols to bioactive theabrownins

Background: Theabrownins (TBs), which are produced from tea leaves, have been shown to have biological. To extract biologically active chemicals from polyphenol structures, an oxidizing enzyme (i.e. laccase) is used to oxidize the polyphenol structure, releasing smaller and more soluble molecular compounds, including TBs. This is a biologically active compound that is beneficial to human health. Therefore, using laccase to purify is significant in enhancing the oxidation process of polyphenols from fresh tea leaves to improve the efficiency of harvesting theabrownins. Methods: to purify laccase, we use a diethylaminoethyl-cellulose (DEAE), Sephadex G-75, and Q Sepharose® columns in a three-step column chromatography procedure. In addition, TBs formed by hydrolysis were determined by high-performance liquid chromatography equipped with a refractive index detector (ultra violet-Vis 271 nm) and ICSep WA-1 Analysis column. Results: In this study, CliLac was effectively purified with a specific activity of 7.58 U/mg from strain Clitopilus prunulus BV18. Using DEAE, Sephadex G-75, and Q Sepharose® columns in a three-step column chromatography procedure, the enzyme was purified to a level of 21.4-fold purity. The enzyme with a molecular weight of 55.2 kDa demonstrated increased pH stability in the acidic range. Biochemical properties of CliLac showed that the optimum pH and temperature were 5.0 and 50°C, respectively. The activity retention was over 80% at pH 5.0 for more than 7 h of incubation. CliLac denatured at temperatures over 60°C. TBs production release increased up to 159 ppm after 72 h of incubation using a purified CliLac (10 U/gds) at 50°C. Conclusions: The study indicates that CliLac is appropriate for oxidizing the polyphenol structure and releases the TBs, which are smaller and more soluble molecular compounds

Enhanced hyaluronic acid production from Priestia flexa N7 isolates

Background: Hyaluronic acid (HA) is a gel-like substance made up of glucuronic acid and N-acetylglucosamine units, capable of absorbing and retaining water, present in hydrated gel form across human and animal tissues. It aids in joint lubrication and moisture retention and acts as a cushion for shock absorption. HA has unique biological properties, promoting fibroblast cell growth, aiding wound healing, and exhibiting low solubility and viscosity, making it an organic ingredient in tissue culture techniques. It is utilized in eye drops and skin ointments and plays a vital role in the extracellular matrix, rendering it invaluable in medical and cosmetic applications, such as treating osteoarthritis and enhancing skin wound recovery. Methods: The methods employed in this study involve isolating microorganisms, screening bacterial strains capable of synthesizing HA, identifying bacteria using molecular biological methods, and researching optimal conditions to select bacterial strains that produce the highest HA concentrations. Results: In this study, strain Priestia flexa N7 was studied for suitable conditions for HA biosynthesis. Bacterial strains were fermented for 48 h on medium containing the following ingredients: glucose (60 g/L); yeast extract (5.0 g/L); peptone (20 g/L); K2HPO4 (2.0 g/L); Na2HPO4 (1.0 g/L); NaCl (2.0 g/L); FeSO4 (1.0 g/l); sodium glutamate (9.0 g/L); and MgSO4.7H2O (2.0 g/L) and pH 8.0 at 37°C under the condition of continuous shaking at 150 rpm. The maximum HA production achieved was 1105 mg/L. Conclusions: The mentioned bacterial strain exhibits significant potential for HA synthesis and is extensively employed in producing items across the health care, medical, food, and cosmetic industries. These findings revealed the most effective HA acid manufacturing strategy for achieving maximum output