Glycolipids are a class of widely studied biosurfactants with excellent applicability in cosmetic and pharmaceutical formulations. This class of biosurfactants includes mannosylerythritol lipids (MELs), which have gained particular interest due to their moisturizing and healing activity for dry and damaged human skin, arising from conditions such as eczema. Traditionally, MELs have been produced by growing certain basidiomycetous yeasts on vegetable oils. However, oils are a comparatively expensive substrate, which negatively affects the economic performance of MEL production. In addition to this, vegetable oils significantly complicate the downstream processing required to produce a product with the required purity for most applications. To address these challenges, this study investigated MEL-A production exclusively from hydrophilic carbon sources by Ustilago maydis DSM 4500. By implementing a fed-batch production strategy, maximum MEL-A concentration of 0.87 g/L was achieved from glucose exclusively. Also, adding micronutrients (such as MnSO) to MEL-A production showed a 24.1% increase in the product titer, implying other metabolites are formed, favoring MEL production.

The production of keratinases was evaluated in submerged fermentation with Aspergillus niger and by pigs' swine hair in a batch bioreactor. Experimental planning was performed to assess the interaction between different variables. The enzyme extract produced was characterized at various pH and temperatures and subjected to enzyme concentration using a biphasic aqueous system and salt/solvent precipitation techniques. In addition, the substrate's potential in reducing hexavalent chromium from synthetic potassium dichromate effluent with an initial concentration of 20 mg L of chromium was evaluated. The resulting enzyme extract showed 89 ± 2 U mL of keratinase. The enzyme concentration resulted in a purification factor of 1.3, while sodium chloride/acetone and ammonium sulfate/acetone resulted in a purification factor of 1.9 and 1.4, respectively. Still using the residual substrate of swine hair from the fermentation, a 94% reduction of hexavalent chromium concentration occurred after 9 h of reaction. Thus, the study proved relevant for producing keratinases, with further environmental applicability and the possibility of concentrating the extract via low-cost processes.

The synthesis of magnesium hydroxide nanoparticles (Mg(OH) NPs) using plant extracts are known to be a practical, economical, and an environmentally friendly approach. In this work, Mg(OH) NPs were synthesized using aqueous leaf extract of Tinospora cordifolia, a medicinal plant commonly found in India. The synthesized Mg(OH) NPs were characterized using various spectroscopic techniques. The ultraviolet-visible (UV-Vis) absorption peak of the Mg(OH) NPs was detected at 289 nm, Fourier transform infrared (FTIR) analysis confirmed the presence of various functional groups, and X-ray diffraction (XRD) patterns revealed the well-crystallized structure of the Mg(OH) NPs. High-resolution transmission electron microscopy (HR-TEM) and scanning electron microscopy (SEM) analyses depicted spherical morphology and an average particle size (PS) of 27.71 nm. The energy-dispersive X-ray (EDX) analysis confirmed the presence of C, O, and Mg elements, and the X-ray photoelectron spectroscopy (XPS) survey spectrum confirmed the elements for the Su 1 s peak at 280.2 eV. The dynamic light scattering (DLS) analysis displayed an average PS of 54.3 nm, and the Zeta potential (ZP) was of 9.89 mV. The fabricated Mg(OH) NPs displayed notable antibacterial activity against S. epidermidis, E. coli, and S. aureus. In addition, these NPs exhibited strong antioxidant properties (> 75%) based on DPPH, ABTS, and hydrogen peroxide (HO) assays. Further, the same NPs exerted a potent anti-inflammatory activity (> 65%) based on COX-1 and COX-2 evaluations. The anti-Alzheimer' disease (AD) potential of Mg(OH) NPs was assessed through effective inhibition (> 70%) of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities. Molecular docking (MD) studies confirmed that caryophyllene has higher binding affinity with AChE (-5.3 kcal/mol) and BuChE (-6.4 kcal/mol) enzymes. This study emphasizes the green synthesis of Mg(OH) NPs using T. cordifolia as a plant source and highlights their potential for biomedical applications.

This study investigates the production of biomethane, and variation in microbial community and coal molecular structures using gas chromatography, 16S rRNA high-throughput sequencing and Fourier transform infrared spectroscopy. Additionally, the factors influencing microbial community structure at a molecular level are discussed. The results demonstrate that bituminous coal exhibits a higher biomethane yield than anthracite coal. In bituminous coal samples, Escherichia and Proteiniphilum are the predominant bacteria at day 0, while Macellibacteroides dominates from days 5 to 35. Methanofollis is the dominated archaea during days 0 to 15, followed by Methanosarcina on day 35. In anthracite coal samples, Soehngenia is the dominant bacterial genus at day 0; however, it transitions to mainly Soehngenia and Aminobacterium within days 5-15 before evolving into Acetomicrobium on day 35. Methanocorpusculum is predominantly found in archaeal communities during days 0-15 but shifts to Methanosarcina on day 35. Alpha diversity analysis reveals that bacterial communities have higher species abundance and diversity compared to archaeal communities. Redundancy analysis indicates a significant correlation between coal molecular structure and bacterial community composition (P value < 0.05), whereas no correlation exists with archaeal community composition (P value > 0.05). The research findings provide theoretical support for revealing the biological gasification mechanisms of coal.

The probiotic fermentation of the bioactive substance gamma-aminobutyric acid (GABA) is an attractive research topic. There is still room for further improvement in reported GABA fermentation methods based on a single substrate (L-glutamic acid or L-monosodium glutamate). Here, we devised a pH auto-buffering strategy to facilitate the fermentation of GABA by Levilactobacillus brevis CD0817. This strategy features a mixture of neutral monosodium L-glutamate plus acidic L-glutamic acid as the substrate. This mixture provides a mild initial pH; moreover, the newly dissolved L-glutamic acid automatically offsets the pH increase caused by substrate decarboxylation, maintaining the acidity essential for GABA fermentation. In this study, a flask trial was first performed to optimize the GABA fermentation parameters of Levilactobacillus brevis CD0817. The optimized parameters were further validated in a 10 L fermenter. The flask trial results revealed that the appropriate fermentation medium was composed of powdery L-glutamic acid (750 g/L), monosodium L-glutamate (34 g/L [0.2 mol/L]), glucose (5 g/L), yeast extract (35 g/L), MnSO·HO (50 mg/L [0.3 mmol/L]), and Tween 80 (1.0 g/L). The appropriate fermentation temperature was 30 °C. The fermenter trial results revealed that GABA was slowly synthesized from 0-4 h, rapidly synthesized until 32 h, and finally reached 353.1 ± 8.3 g/L at 48 h, with the pH increasing from the initial value of 4.56 to the ultimate value of 6.10. The proposed pH auto-buffering strategy may be popular for other GABA fermentations.

D-pantothenate, universally acknowledged as vitamin B5, has garnered considerable interest owing to its crucial functionality in the feed, pharmaceutical, and cosmeceutical sectors. Development of microbial strains for D-pantothenate hyperproducer has emerged as a prominent research direction in recent years. Herein, we converted an engineered Escherichia coli with low yield to a plasmid-free hyperproducer of D-pantothenate using multiplex combinatorial strategies. First, an initial strain was obtained through prolonging the cell lifespan. To promote the accumulation of D-pantothenic acid, the supply of cofactors was adaptively enhanced. Additionally, the heterologous gene panE from Pseudomonas aeruginosa, which encodes ketopantoate reductase (EC 1.1.1.169) catalyzing the synthesis of d-pantoate from α-ketopantoate, was screened and integrated into the chromosome. Subsequently, a strategy of acetate recycling and NOG pathway reconstruction were introduced and successfully to improve the D-pantothenate titer to 5.48 g/L. Additionally, we screened the regulatory factors and optimized its second codon to further increase the DPA yield of the engineered strains to 6.02 g/L in shake flask. The final engineered strain DS6 could efficiently produce 72.40 g/L D-pantothenate, which is 3.18-fold higher than the original strain. This study proposed a novel multiplex combination strategy for developing microbial cell factory of D-pantothenate, which was beneficial for the advancement of efficient D-pantothenate production.

Immobilized fillers have been increasingly utilized in biotrickling filters (BTFs) due to their positive impact on shock load resistance and recovery performance. However, due to the inherent characteristics of its immobilized carrier, the immobilized filler is prone to swelling during the long-term operation of the system, resulting in increased pressure drop. Polyurethane (PU) sponge was used as the cross-linked skeleton of immobilized filler and compared with direct emulsified cross-linked immobilized filler for treating ethylbenzene gas. In the early stage, both fillers can maintain good performance despite changes in the inlet concentration and short-term stagnation. However, on the 107th day of operation, the immobilized filler experienced swelling, and the pressure drop sharply increased to 137.2 Pa, while the PU immobilized filler was still able to maintain a low-pressure drop level. The results of the microbial diversity analysis revealed that the microbial community structure of PU immobilized fillers remained relatively stable when responding to the fluctuations in operating conditions. PU sponges as the skeleton can effectively prolong the service life of the immobilized filler and improve the performance of the biotrickling filter.

Protein engineering is a powerful tool for designing or modifying therapeutic proteins for enhanced efficacy, increased safety, reduced immunogenicity, and improved delivery. Fusion proteins are an important group of therapeutic compounds that often require an ideal linker to combine diverse domains to fulfill the desired function. GGGGS [(G4S)n] linkers are commonly used during the engineering of proteins because of their flexibility and resistance to proteases. However, unexpected truncation was observed in the linker of a bispecific antibody, which presented challenges in terms of production and quality. In this work, a bispecific antibody containing 5*G4S was investigated, and the truncation position of the linkers was confirmed. Our investigation revealed that codon optimization, which can overcome the negative influence of a high repetition rate and high GC content in the (G4S)n linker, may reduce the truncation rate from 5-10% to 1-5%. Moreover, the probability of truncation when a shortened 3* or 4*G4S linker was used was much lower than that when a 5*G4S linker was used in mammalian cells. In the case of expressing a bispecific antibody, the bioactivity and purity of the product containing a shorter G4S linker were further investigated and are discussed.

Due to the prevalence of drug-resistant bacteria and the ongoing shortage of novel antibiotics as well as the challenge of treating breast cancer, the therapeutic and clinical sectors are consistently seeking effective nanomedicines. The incorporation of metal oxide nanoparticles with biological macromolecules and an organic compound emerges as a promising strategy to enhance breast cancer treatment and antibacterial activity against drug-resistant bacteria in various biomedical applications. This study aims to synthesize a unique nanocomposite consisting of CeO embedded with folic acid and carboxymethyl cellulose (CFC NC) via a green precipitation method using Moringa oleifera. Various spectroscopic and microscopic analyses are utilized to decipher the physicochemical characteristics of CFC NC and active phytocompounds of Moringa oleifera. Antibacterial study against MRSA (Methicillin-resistant Staphylococcus aureus) demonstrated a higher activity (95.6%) for CFC NC compared to its counterparts. The impact is attributed to reactive oxygen species (ROS), which induces a strong photo-oxidative stress, leading to the destruction of bacteria. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of CFC NC are determined as 600 µg/mL and 1000 µg/mL, respectively. The anticancer activity against breast cancer cell resulted in the IC concentration of 10.8 μg/mL and 8.2 μg/mL for CeO and CFC NC respectively.The biocompatibility test was conducted against fibroblast cells and found 85% of the cells viable, with less toxicity. Therefore, the newly synthesized CFC NC has potential applications in healthcare and industry, enhancing human health conditions.

The study focused on rhamnolipid production by batch fermentation of Pseudomonas aeruginosa USM-AR2 in a 3-L stirred-tank reactor (STR) using palm sludge oil (PSO) as the sole carbon source. The impact of various agitation rates towards the dispersion of PSO in the medium was evaluated to improve biomass growth and rhamnolipid production. A mechanical foam collection and recycling system was designed and retrofitted to the STR to overcome severe foam formation during fermentation. The maximum biomass produced was 11.29 ± 0.20 g/L obtained at 400 rpm, while the maximum rhamnolipid production was 5.06 ± 1.17 g/L at 600 rpm, giving a rhamnolipid productivity of 0.023 g/L/h. High agitation enhances substrate availability by breaking the hydrophobic semi-solid PSO into smaller substrate particles, increasing surface contact area, thus facilitating the PSO utilisation by P. aeruginosa USM-AR2, thereby inducing rhamnolipid production. This study further demonstrates the ability of rhamnolipid to solubilize and disperse sludge oil, which typically remains a solid at room temperature, in the liquid medium. GCMS analysis showed that five fatty acids, namely palmitic acid, myristic acid, stearic acid, methyl ester and linoleic acid, have been utilised. The rhamnolipid showed an oil spreading test result of 160 mm of waste engine oil displacement compared to control using distilled water that remained non-displaced, and a critical micelle concentration (CMC) of 17 mg/L. In emulsification index (E) assay, the rhamnolipid was shown to emulsify toluene (66.7% ± 7.2), waste engine oil (58.3% ± 7.2), kerosene (41.8% ± 4.8) and n-hexane (33.1% ± 5.7). UPLC analysis on rhamnolipid revealed a congener mixture of rhamnolipid, namely di-rhamnolipid and mono-rhamnolipid mixture. This is the first report on the employment of an integrated foam control reactor system with PSO as the carbon source for rhamnolipid production by P. aeruginosa USM-AR2 culture.

The efficient and eco-friendly removal of lignin is a critical challenge for bioethanol production from lignocellulosic biomass. Herein, we report the integration of laccase with deep eutectic solvents (DESs) for the pretreatment of corn stover to enhance the production of reducing sugars. Three betaine-based DESs were prepared and tested for their effects on the activity and stability of a bacterial laccase from Bacillus amyloliquefaciens LC02. The aqueous solution of DESs showed no adverse influence on laccase activity, and the laccase thermostability was improved in the presence of DESs. More than 95% of the laccase activity was retained in the DESs solution during the first hour of incubation at 70 °C. A red shift in the fluorescence spectra was observed for the laccase in the presence of DESs, indicating conformational changes. The laccase was able to degrade a dimeric lignin model compound by cleaving its β-O-4 bond. The transformation products were identified using LC-MS. The maximal lignin removal from corn stover was achieved by pretreatment using laccase in combination with the betaine-glycerol DES, which also resulted in a yield of fermentable sugar that was 130% higher than the control. This combination strategy provides guidance on the application of laccase and DESs in the pretreatment of lignocellulosic biomass.

Droplet-based bioprinting (DBB) allows for high precision, noncontact, and on-demand distribution of bioinks, hence it has been widely utilized in the preparation of bacteria-laden living materials (BLMs). Nonetheless, discontinuous ink deposition makes it challenging to fabricate large-sized intact living structures via this technique. Herein, we explore the way of using DBB to construct centimeter-scale BLMs with bespoke geometries, and further demonstrate its potential applicability in sensing-responsive device by integrating engineered bacteria. We first established a DBB method based on printing-path design, which does not require hardware modification. This strategy was able to produce customized 3D-hydrogel structures with high shape fidelity. Then, we confirmed the excellent biocompatibility of the above biofabrication approach. The Escherichia coli survived 93% ± 4.0% in printed BLMs, with uniform distribution throughout the structure. As a proof-of-concept, we finally manufactured a test strip-like heavy metal biosensor capable of plug-and-play detecting mercury (II) in water using the aforesaid approach. To our knowledge, this is the first study to employ 3D bioprinted BLMs for the detection of prevalent heavy metal pollutants. Our research shed light on the versatility of DBB in BLMs construction, which is not restricted to two-dimensional patterns. Moreover, our results are expected to innovate heavy metal biodetection and improve detection efficiency and sensitivity.

The effects of dilute acid prehydrolysate from poplar were investigated and compared in the enzymatic hydrolysis, fermentation, and simultaneous saccharification fermentation (SSF) in this study. The improvement of enzymatic hydrolysis and fermentation with resin adsorption and surfactant addition has also been represented. A total of 16 phenolic alcohols, aldehydes, acids and 3 furan derivatives in the prehydrolysates were identified and quantified by gas chromatography/mass spectrometry (GC/MS). The degree of inhibition from the phenolic compounds (26.55%) in prehydrolysate on the enzymatic hydrolysis was much higher than carbohydrates-derived inhibitors (0.52-4.64%). Around 40% degree of inhibition was eliminated in Avicel enzymatic hydrolysis when 75% of prehydrolysates phenolic compounds were removed by resin adsorption. This showed distinguishing inhibition degrees of various prehydrolysate phenolic compounds. Inhibition of prehydrolysate on enzymatic hydrolysis was more dosage-dependent, while their suppression on the fermentation showed a more complicated mode: fermentation could be terminated by the untreated prehydrolysate, while a small number of prehydrolysate inhibitors even improved the glucose consumption and ethanol production in the fermentation. Correlated with this distinct inhibition modes of prehydrolysate, the improvement of Tween 80 addition in SSF was around 7.10% for the final ethanol yield when the glucose accumulation was promoted by 76.6%.

The present work focused on inline Raman spectroscopy monitoring of SARS-CoV-2 VLP production using two culture media by fitting chemometric models for biochemical parameters (viable cell density, cell viability, glucose, lactate, glutamine, glutamate, ammonium, and viral titer). For that purpose, linear, partial least square (PLS), and nonlinear approaches, artificial neural network (ANN), were used as correlation techniques to build the models for each variable. ANN approach resulted in better fitting for most parameters, except for viable cell density and glucose, whose PLS presented more suitable models. Both were statistically similar for ammonium. The mean absolute error of the best models, within the quantified value range for viable cell density (375,000-1,287,500 cell/mL), cell viability (29.76-100.00%), glucose (8.700-10.500 g/), lactate (0.019-0.400 g/L), glutamine (0.925-1.520 g/L), glutamate (0.552-1.610 g/L), viral titer (no virus quantified-7.505 log PFU/mL) and ammonium (0.0074-0.0478 g/L) were, respectively, 41,533 ± 45,273 cell/mL (PLS), 1.63 ± 1.54% (ANN), 0.058 ± 0.065 g/L (PLS), 0.007 ± 0.007 g/L (ANN), 0.007 ± 0.006 g/L (ANN), 0.006 ± 0.006 g/L (ANN), 0.211 ± 0.221 log PFU/mL (ANN), and 0.0026 ± 0.0026 g/L (PLS) or 0.0027 ± 0.0034 g/L (ANN). The correlation accuracy, errors, and best models obtained are in accord with studies, both online and offline approaches while using the same insect cell/baculovirus expression system or different cell host. Besides, the biochemical tracking throughout bioreactor runs using the models showed suitable profiles, even using two different culture media.

For the first time is reported the comparison of solid biocatalysts derived from Candida rugosa lipase (CRL) immobilized on different lignocellulosic wastes (rice husk, brewer's spent grain, hemp tea waste, green tea waste, vine bark, and spent coffee grounds) focusing on the characterization of these materials and their impact on the lipase-support interaction. The wastes were subjected to meticulous characterization by ATR-FTIR, BET, and SEM analysis, besides lignin content and hydrophobicity determination. Investigating parameters influencing immobilization performance revealed the importance of morphology, textural properties, and hydrophobic interactions revealed the importance of morphology, textural properties and especially hydrophobic interactions which resulted in positive correlations between surface hydrophobicity and lipase immobilization efficiency. Hemp tea waste and spent coffee grounds demonstrated superior immobilization performances (7.20 U/g and 8.74 U/g immobilized activity, 102.3% and 33.5% efficiency, 13.4% and 15.4% recovery, respectively). Moreover, they demonstrated good temporal stability (100% and 92% residual activity after 120 days, respectively) and retained 100% of their immobilized activity after five reuses in the hydrolysis of p-nitrophenyl palmitate in hexane. In addition, the study of enzymatic desorption caused by ionic strength and detergent treatments indicated mixed hydrophobic and electrostatic interactions in rice husk, vine bark, and spent coffee grounds supports, while hemp tea waste and green tea waste were dominated by hydrophobic interactions.

Lipase is one of the most widely studied and applied biocatalysts. Due to the high enzyme leakage rate of the immobilization method of physical adsorption, we propose a new lipase immobilization method, based on the combination of macroporous resin adsorption and organic polymer coating. The immobilized Candida antarctica lipase B (CALB@resin-CAB) was prepared by combining the macroporous resin adsorption with cellulose acetate butyrate coating, and its structure was characterized by various analytic methods. Immobilized lipase was applied for biodiesel production using acidified palm oil as the starting material, the conversion rate achieved as high as 98.5% in two steps. Furthermore, the immobilized lipase displayed satisfactory stability and reusability in biodiesel production. When the aforementioned reaction was carried out in a continuous flow packed bed system, the yield of biodiesel was 94.8% and space-time yield was 2.88 g/(mL∙h). The immobilized lipase CALB@resin-CAB showed high catalytic activity and stability, which has good potential for industrial application in the field of oil processing.

Mammalian cell cultures in laboratories are performed in static and dynamic methods, and cell growth indices are higher in dynamic mode. In this study, a lab-scale stirred bioreactor using a vibrating disc and a suitable setup has been introduced for dynamic cell culture, which creates proper mixing at low shear stress. 15 experiments have been done by Raji cell in batch mode using Box-Behnken design to quantitatively investigate the effect of mechanical and geometrical factors of this bioreactor on cell culture indices. Three structural factors, including disc diameter, vibration amplitude, and the height of the disc placement have been selected as the main factors. Three cell growth indices including the specific growth rate, the maximum cell concentration, and productivity have been considered as biological responses. Resulting models predict the value of each index under different settings of the factors with good accuracy. Results show that the disc diameter has the greatest effect among the investigated factors. Also, the specific growth rate, the natural logarithm of the maximum cell concentration, and productivity are about 0.033 (1/h), 13.2, and 5133 (cells/hmL), respectively by using a 25 (mm) disc with a vibration amplitude of 2.5 up to 3 (mm), and a placement height of 40 up to 60 (mm).

The microalgal-bacterial granular sludge (MBGS) process is attracting attention as a green wastewater treatment technology. However, research on the application of MBGS in lake water remediation is limited. Thus, this experiment investigated the feasibility and the efficacy of the MBGS process for the treatment of natural lake water in a continuous-flow tubular reactor. The average removal efficiencies of COD, NH-N, NO-N, NO-N, TN, PO-P, TP, and turbidity by MBGS system in the day/night cycles were 50.10/61.39%, 63.52/75.23%, 43.37/73.57%, 90.72/93.48%, 78.30/80.02%, 71.13/74.62%, 65.08/70.57%, 92.32/89.84%, respectively. As the experiment progressed, the total chlorophyll content in MBGS decreased as the granule size increased, while the extracellular polymeric substances content increased, suggesting that the lake water contributed to bacterial growth and favored the stability of MBGS. Moreover, the eukaryotic microorganisms were dominated by Chlorophyta and Rotifera, and prokaryotic microorganisms were dominated by Proteobacteria in MBGS. By promoting the decomposition of various organic compounds in the lake water and inhibiting sludge expansion, these microorganisms help the MBGS system to maintain excellent granular characteristics and performance. Overall, the MBGS system proved to be a feasible option for the remediation of natural lake waters.

Freshwater microalga Haematococcus lacustris rich in astaxanthin, as a supplemental live diet can directly supply natural astaxanthin to the aquaculture organisms, except marine aquaculture organisms, since H. lacustris cannot tolerate seawater salinity. The objective of the present study is to provide a salinity acclimation method that allows H. lacustris to survive and accumulate astaxanthin with the aim of developing a novel supplemental live diet for marine aquaculture organisms. H. lacustris cultured in freshwater was subjected to different stepwise salinity acclimation processes (two-, three-, and four-shift). As the controls, H. lacustris was exposed to five constant salinities conditions (0, 0.05, 0.075, 0.3, and 0.6 M NaCl, respectively). Among the controls, almost all cells in the 0.3 M and 0.6 M NaCl conditions died immediately. In contrast, H. lacustris in the stepwise salinity acclimation processes survived in 0.6 M NaCl (equivalent to seawater salinity of 35 psu), showing the highest living-cell proportion (50.0%) and astaxanthin yield (0.72 mg·L) in the four-shift. The present study first demonstrated that H. lacustris tolerated seawater salinity through a stepwise acclimation process, proving a new strategy to supply live microalgal diets rich in natural astaxanthin for marine aquaculture.

Isoprene is an important component in rubber production, which can be produced using the E. coli mevalonic acid (MVA) pathway, and this method has the advantage of green environmental protection and sustainable. However, due to the excessive accumulation of intermediates, the growth of cells was inhibited and the enzyme activity decreased gradually, so it was difficult to increase the yield of isoprene. The immobilized enzyme has the characteristics of high stability and strong reusability, so in this study, the immobilized enzyme was added to the fermentation process of isoprene production by mevalonate metabolizing bacteria (PT-P), to explore the effect on isoprene synthesis. Under the optimum conditions, compared with PT-P fermentation alone, the enzyme catalyzes the conversion of MVA with an efficiency of up to 50.86%, and the yield of isoprene increased by about 30%, reaching 234.47 mg/L.

This century has seen the rise of antibiotic resistance as a significant public health problem. In addition, oxidative stress may also be a factor in selecting resistant strains of bacteria. The current study analyzed microbially produced hyaluronic acid's antibacterial activity and antioxidant activity. It had significant antibacterial action against strains of Staphylococcus aureus and Escherichia coli, with the IC value obtained being 487.65 µg mL for antioxidant assay. Our molecular docking investigations of hyaluronic acid on tyrosyl-tRNA synthetase (Staphylococcus aureus: -6.13 kcal/mol, Escherichia coli: -5.79 kcal/mol) and topoisomerase II DNA gyrase (Staphylococcus aureus: -5.02 kcal/mol, Escherichia coli: -4.90 kcal/mol) confirmed the ligands' possible binding mode to the appropriate targets' sites. We also employed molecular dynamics simulation and showed that HA binds more strongly with 1JIL (-85.455 ± 12.623 kJ/mol) compared to 2YXN (-49.907 ± 64.191 kJ/mol), 5CDP (-47.285 ± 13.925 kJ/mol), and 6RKS (-45.306 ± 21.338 kJ/mol). We also report that the ligand forms several hydrogen bonds in molecular simulation, implying regular interaction with key residues of the enzymes. The results in this study indicate the potential use of HA in the vast field of applications having both asthetic and medicinal values.