Antibiotic resistance is a critical problem that results in a high morbidity and mortality rate. The process of discovering new chemotherapy and antibiotics is challenging, expensive, and time-consuming, with only a few getting approved for clinical use. Therefore, screening already-approved drugs to combat pathogens such as bacteria that cause serious infections in humans and animals is highly encouraged. In this work, we aim to identify approved antibiotics that can inhibit the mecA antibiotic resistance gene found in methicillin-resistant Staphylococcus aureus (MRSA) strains. The MecA protein sequence was utilized to perform a BLAST search against a drug database containing 4302 approved drugs. The results revealed that 50 medications, including known antibiotics for other bacterial strains, targeted the mecA antibiotic resistance gene. In addition, a structural similarity approach was employed to identify existing antibiotics for S. aureus, followed by molecular docking. The results of the docking experiment indicated that six drugs had a high binding affinity to the mecA antibiotic resistance gene. Furthermore, using the structural similarity strategy, it was discovered that afamelanotide, an approved drug with unclear antibiotic activity, had a strong binding affinity to the MRSA-MecA protein. These findings suggest that certain already-approved drugs have potential in chemotherapy against drug-resistant pathogenic bacteria, such as MRSA.
{"title":"Computational Screening of Approved Drugs for Inhibition of the Antibiotic Resistance Gene <i>mecA</i> in Methicillin-Resistant <i>Staphylococcus aureus</i> (MRSA) Strains.","authors":"Benson Otarigho, Mofolusho O Falade","doi":"10.3390/biotech12020025","DOIUrl":"https://doi.org/10.3390/biotech12020025","url":null,"abstract":"<p><p>Antibiotic resistance is a critical problem that results in a high morbidity and mortality rate. The process of discovering new chemotherapy and antibiotics is challenging, expensive, and time-consuming, with only a few getting approved for clinical use. Therefore, screening already-approved drugs to combat pathogens such as bacteria that cause serious infections in humans and animals is highly encouraged. In this work, we aim to identify approved antibiotics that can inhibit the <i>mecA</i> antibiotic resistance gene found in methicillin-resistant <i>Staphylococcus aureus</i> (MRSA) strains. The MecA protein sequence was utilized to perform a BLAST search against a drug database containing 4302 approved drugs. The results revealed that 50 medications, including known antibiotics for other bacterial strains, targeted the <i>mecA</i> antibiotic resistance gene. In addition, a structural similarity approach was employed to identify existing antibiotics for <i>S. aureus</i>, followed by molecular docking. The results of the docking experiment indicated that six drugs had a high binding affinity to the <i>mecA</i> antibiotic resistance gene. Furthermore, using the structural similarity strategy, it was discovered that afamelanotide, an approved drug with unclear antibiotic activity, had a strong binding affinity to the MRSA-MecA protein. These findings suggest that certain already-approved drugs have potential in chemotherapy against drug-resistant pathogenic bacteria, such as MRSA.</p>","PeriodicalId":34490,"journal":{"name":"BioTech","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10123713/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9382418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Melanin is a functional pigment that is used in various products. It can be produced by Streptomyces antibioticus NRRL B-1701 when supplemented with L-tyrosine. Arthrospira (Spirulina) platensis is a cyanobacterium with high protein content, including the protein phycocyanin (PC). During PC's extraction, biomass residues are generated, and these residues still contain various amino acids, especially L-tyrosine, which can be used as a low-cost supplement for melanin production. Thus, this study employed a hydrolysate of A. platensis biomass residue for L-tyrosine substitution. The effects of two drying methods, namely, lyophilization and dying via a hot air oven, on the proximate composition and content of L-tyrosine in the biomass residue were evaluated. The highest L-tyrosine (0.268 g L-tyrosine/100 g dried biomass) concentration was obtained from a hot-air-oven-dried biomass residue hydrolysate (HAO-DBRH). The HAO-DBRH was then used as a low-cost L-tyrosine supplement for maximizing melanin production, which was optimized by the response surface methodology (RSM) through central composite design (CCD). Using the RSM-CCD, the maximum level of melanin production achieved was 0.24 g/L, which is approximately four times higher than it was before optimization. This result suggests that A. platensis residue hydrolysate could be an economically feasible and low-cost alternative source of L-tyrosine for the production of melanin.
黑色素是一种用于各种产品的功能性色素。在添加l -酪氨酸的条件下,链霉菌NRRL B-1701可产生该菌。Arthrospira Arthrospira platensis是一种蛋白质含量高的蓝藻菌,其中包括蛋白质藻蓝蛋白(PC)。PC在提取过程中会产生生物质残渣,这些残渣中仍然含有多种氨基酸,尤其是l -酪氨酸,可以作为黑色素生产的低成本补充。因此,本研究采用platensis生物质渣的水解产物替代l -酪氨酸。研究了冻干和热风炉干燥两种干燥方法对生物质残渣中l -酪氨酸近似组成和含量的影响。热风炉干燥生物质残渣水解液(HAO-DBRH)的l -酪氨酸浓度最高(0.268 g l -酪氨酸/100 g干燥生物质)。然后将HAO-DBRH作为低成本的l -酪氨酸补充剂,通过响应面法(RSM)通过中心复合设计(CCD)对其进行优化,以最大化黑色素的产生。使用RSM-CCD,获得的最大黑色素产量为0.24 g/L,比优化前提高了约4倍。这一结果表明,platensis残渣水解物可能是一种经济可行且低成本的l -酪氨酸替代来源,用于黑色素的生产。
{"title":"Optimization of Melanin Production by <i>Streptomyces antibioticus</i> NRRL B-1701 Using <i>Arthrospira (Spirulina) platensis</i> Residues Hydrolysates as Low-Cost L-tyrosine Supplement.","authors":"Oranit Kraseasintra, Sritip Sensupa, Kanjana Mahanil, Sada Yoosathaporn, Jeeraporn Pekkoh, Sirasit Srinuanpan, Wasu Pathom-Aree, Chayakorn Pumas","doi":"10.3390/biotech12010024","DOIUrl":"https://doi.org/10.3390/biotech12010024","url":null,"abstract":"<p><p>Melanin is a functional pigment that is used in various products. It can be produced by <i>Streptomyces antibioticus</i> NRRL B-1701 when supplemented with L-tyrosine. <i>Arthrospira (Spirulina) platensis</i> is a cyanobacterium with high protein content, including the protein phycocyanin (PC). During PC's extraction, biomass residues are generated, and these residues still contain various amino acids, especially L-tyrosine, which can be used as a low-cost supplement for melanin production. Thus, this study employed a hydrolysate of <i>A. platensis</i> biomass residue for L-tyrosine substitution. The effects of two drying methods, namely, lyophilization and dying via a hot air oven, on the proximate composition and content of L-tyrosine in the biomass residue were evaluated. The highest L-tyrosine (0.268 g L-tyrosine/100 g dried biomass) concentration was obtained from a hot-air-oven-dried biomass residue hydrolysate (HAO-DBRH). The HAO-DBRH was then used as a low-cost L-tyrosine supplement for maximizing melanin production, which was optimized by the response surface methodology (RSM) through central composite design (CCD). Using the RSM-CCD, the maximum level of melanin production achieved was 0.24 g/L, which is approximately four times higher than it was before optimization. This result suggests that <i>A. platensis</i> residue hydrolysate could be an economically feasible and low-cost alternative source of L-tyrosine for the production of melanin.</p>","PeriodicalId":34490,"journal":{"name":"BioTech","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10046677/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9209306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The tremendous problem with plastic waste accumulation has determined an interest in biodegradation by effective degraders and their enzymes, such as thermophilic enzymes, which are characterized by high catalytic rates, thermostability, and optimum temperatures close to the melting points of some plastics. In the present work, we report on the ability of a thermophilic lipase, by Brevibacillus thermoruber strain 7, to degrade Ɛ-polycaprolactone (PCL), as well as the enzyme purification, the characterization of its physicochemical properties, the product degradation, and its disruptive effect on the PCL surface. The pure enzyme showed the highest reported optimum temperature at 55 °C and a pH of 7.5, while its half-life at 60 °C was more than five hours. Its substrate specificity referred the enzyme to the subgroup of lipases in the esterase group. A strong inhibitory effect was observed by detergents, inhibitors, and Fe3+ while Ca2+ enhanced its activity. The monomer Ɛ-caprolactone was a main product of the enzyme degradation. Similar elution profiles of the products received after treatment with ultra-concentrate and pure enzyme were observed. The significant changes in PCL appearance comprising the formation of shallower or deeper in-folds were observed after a week of incubation. The valuable enzyme properties of the lipase from Brevibacillus thermoruber strain 7, which caused a comparatively quick degradation of PCL, suggests further possible exploration of the enzyme for effective and environment-friendly degradation of PCL wastes in the area of thermal basins, or in thermophilic remediation processes.
{"title":"A Thermostable Lipase Isolated from <i>Brevibacillus thermoruber</i> Strain 7 Degrades Ɛ-Polycaprolactone.","authors":"Nikolina Atanasova, Tsvetelina Paunova-Krasteva, Margarita Kambourova, Ivanka Boyadzhieva","doi":"10.3390/biotech12010023","DOIUrl":"https://doi.org/10.3390/biotech12010023","url":null,"abstract":"<p><p>The tremendous problem with plastic waste accumulation has determined an interest in biodegradation by effective degraders and their enzymes, such as thermophilic enzymes, which are characterized by high catalytic rates, thermostability, and optimum temperatures close to the melting points of some plastics. In the present work, we report on the ability of a thermophilic lipase, by <i>Brevibacillus thermoruber</i> strain 7, to degrade Ɛ-polycaprolactone (PCL), as well as the enzyme purification, the characterization of its physicochemical properties, the product degradation, and its disruptive effect on the PCL surface. The pure enzyme showed the highest reported optimum temperature at 55 °C and a pH of 7.5, while its half-life at 60 °C was more than five hours. Its substrate specificity referred the enzyme to the subgroup of lipases in the esterase group. A strong inhibitory effect was observed by detergents, inhibitors, and Fe<sup>3+</sup> while Ca<sup>2+</sup> enhanced its activity. The monomer Ɛ-caprolactone was a main product of the enzyme degradation. Similar elution profiles of the products received after treatment with ultra-concentrate and pure enzyme were observed. The significant changes in PCL appearance comprising the formation of shallower or deeper in-folds were observed after a week of incubation. The valuable enzyme properties of the lipase from <i>Brevibacillus thermoruber</i> strain 7, which caused a comparatively quick degradation of PCL, suggests further possible exploration of the enzyme for effective and environment-friendly degradation of PCL wastes in the area of thermal basins, or in thermophilic remediation processes.</p>","PeriodicalId":34490,"journal":{"name":"BioTech","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10046884/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9202484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Svetlana V Kamzolova, Vladimir A Samoilenko, Julia N Lunina, Igor G Morgunov
Isocitric acid (ICA) refers to a group of promising regulators of energy metabolism which has antistress, antihypoxic, and antioxidant activities. In this paper, we reported a process of ICA production from rapeseed oil using yeast Yarrowia lipolytica VKM Y-2373 in a 500-L fermentor. The producer synthesized 64.1 g/L ICA with a product yield of 0.72 g/g and a productivity 0.54 g/L·h. We also developed an effective purification method, including a cell separation, clarification, concentration, acidification, and crystallization process, which resulted in the formation of the crystals of monopotassium salt of ICA with a purity of 99.0-99.9%. To the best of our knowledge, this is the first report on an ICA production process at an upscaled bioreactor level.
{"title":"Large-Scale Production of Isocitric Acid Using <i>Yarrowia lipolytica</i> Yeast with Further Down-Stream Purification.","authors":"Svetlana V Kamzolova, Vladimir A Samoilenko, Julia N Lunina, Igor G Morgunov","doi":"10.3390/biotech12010022","DOIUrl":"https://doi.org/10.3390/biotech12010022","url":null,"abstract":"<p><p>Isocitric acid (ICA) refers to a group of promising regulators of energy metabolism which has antistress, antihypoxic, and antioxidant activities. In this paper, we reported a process of ICA production from rapeseed oil using yeast <i>Yarrowia lipolytica</i> VKM Y-2373 in a 500-L fermentor. The producer synthesized 64.1 g/L ICA with a product yield of 0.72 g/g and a productivity 0.54 g/L·h. We also developed an effective purification method, including a cell separation, clarification, concentration, acidification, and crystallization process, which resulted in the formation of the crystals of monopotassium salt of ICA with a purity of 99.0-99.9%. To the best of our knowledge, this is the first report on an ICA production process at an upscaled bioreactor level.</p>","PeriodicalId":34490,"journal":{"name":"BioTech","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10046092/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9202481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rodrigo Lira de Oliveira, Aldeci França Araújo Dos Santos, Bianca Alencar Cardoso, Thayanne Samille da Silva Santos, Galba Maria de Campos-Takaki, Tatiana Souza Porto, Camila Souza Porto
β-fructofuranosidases (FFases) are enzymes involved in sucrose hydrolysis and can be used in the production of invert sugar and fructo-oligosaccharides (FOS). This last is an important prebiotic extensively used in the food industry. In the present study, the FFase production by Aspergillus tamarii Kita UCP 1279 was assessed by solid-state fermentation using a mixture of wheat and soy brans as substrate. The FFase presents optimum pH and temperature at 5.0-7.0 and 60 °C, respectively. According to the kinetic/thermodynamic study, the FFase was relatively stable at 50 °C, a temperature frequently used in industrial FOS synthesis, using sucrose as substrate, evidenced by the parameters half-life (115.52 min) and D-value (383.76 min) and confirmed by thermodynamic parameters evaluated. The influence of static magnetic field with a 1450 G magnetic flux density presented a positive impact on FFase kinetic parameters evidenced by an increase of affinity of enzyme by substrate after exposition, observed by a decrease of 149.70 to 81.73 mM on Km. The results obtained indicate that FFases present suitable characteristics for further use in food industry applications. Moreover, the positive influence of a magnetic field is an indicator for further developments of bioprocesses with the presence of a magnetic field.
{"title":"Production, Kinetic/Thermodynamic Study, and Evaluation of the Influence of Static Magnetic Field on Kinetic Parameters of β-Fructofuranosidase from <i>Aspergillus tamarii</i> Kita UCP 1279 Produced by Solid-State Fermentation.","authors":"Rodrigo Lira de Oliveira, Aldeci França Araújo Dos Santos, Bianca Alencar Cardoso, Thayanne Samille da Silva Santos, Galba Maria de Campos-Takaki, Tatiana Souza Porto, Camila Souza Porto","doi":"10.3390/biotech12010021","DOIUrl":"https://doi.org/10.3390/biotech12010021","url":null,"abstract":"<p><p>β-fructofuranosidases (FFases) are enzymes involved in sucrose hydrolysis and can be used in the production of invert sugar and fructo-oligosaccharides (FOS). This last is an important prebiotic extensively used in the food industry. In the present study, the FFase production by <i>Aspergillus tamarii</i> Kita UCP 1279 was assessed by solid-state fermentation using a mixture of wheat and soy brans as substrate. The FFase presents optimum pH and temperature at 5.0-7.0 and 60 °C, respectively. According to the kinetic/thermodynamic study, the FFase was relatively stable at 50 °C, a temperature frequently used in industrial FOS synthesis, using sucrose as substrate, evidenced by the parameters half-life (115.52 min) and <i>D</i>-value (383.76 min) and confirmed by thermodynamic parameters evaluated. The influence of static magnetic field with a 1450 G magnetic flux density presented a positive impact on FFase kinetic parameters evidenced by an increase of affinity of enzyme by substrate after exposition, observed by a decrease of 149.70 to 81.73 mM on <i>K<sub>m</sub></i>. The results obtained indicate that FFases present suitable characteristics for further use in food industry applications. Moreover, the positive influence of a magnetic field is an indicator for further developments of bioprocesses with the presence of a magnetic field.</p>","PeriodicalId":34490,"journal":{"name":"BioTech","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10046036/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9202480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Juan Camilo Zárate-Moreno, Diana Marcela Escobar-Sierra, Rigoberto Ríos-Estepa
Chitosan has gained agro-industrial interest due to its potential applications in food preservation. In this work, chitosan applications for exotic fruit coating, using feijoa as a case of study, were evaluated. For this, we synthetized and characterized chitosan from shrimp shells and tested its performance. Chemical formulations for coating preparation using chitosan were proposed and tested. Mechanical properties, porosity, permeability, and fungal and bactericidal characteristics were used to verify the potential application of the film in the protection of fruits. The results indicated that synthetized chitosan has comparable properties to commercial chitosan (deacetylation degree > 82%), and, for the case of feijoa, the chitosan coating achieved significant reduction of microorganisms and fungal growth (0 UFC/mL for sample 3). Further, membrane permeability allowed oxygen exchange suitable for fruit freshness and natural physiological weight loss, thus delaying oxidative degradation and prolonging shelf-life. Chitosan's characteristic of a permeable film proved to be a promising alternative for the protection and extension of the freshness of post-harvest exotic fruits.
{"title":"Development and Evaluation of Chitosan-Based Food Coatings for Exotic Fruit Preservation.","authors":"Juan Camilo Zárate-Moreno, Diana Marcela Escobar-Sierra, Rigoberto Ríos-Estepa","doi":"10.3390/biotech12010020","DOIUrl":"https://doi.org/10.3390/biotech12010020","url":null,"abstract":"<p><p>Chitosan has gained agro-industrial interest due to its potential applications in food preservation. In this work, chitosan applications for exotic fruit coating, using feijoa as a case of study, were evaluated. For this, we synthetized and characterized chitosan from shrimp shells and tested its performance. Chemical formulations for coating preparation using chitosan were proposed and tested. Mechanical properties, porosity, permeability, and fungal and bactericidal characteristics were used to verify the potential application of the film in the protection of fruits. The results indicated that synthetized chitosan has comparable properties to commercial chitosan (deacetylation degree > 82%), and, for the case of feijoa, the chitosan coating achieved significant reduction of microorganisms and fungal growth (0 UFC/mL for sample 3). Further, membrane permeability allowed oxygen exchange suitable for fruit freshness and natural physiological weight loss, thus delaying oxidative degradation and prolonging shelf-life. Chitosan's characteristic of a permeable film proved to be a promising alternative for the protection and extension of the freshness of post-harvest exotic fruits.</p>","PeriodicalId":34490,"journal":{"name":"BioTech","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9944848/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9327262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, biocompatible electrospun nanofiber scaffolds were produced using poly(-caprolactone (PCL)/chitosan (CS) and Nigella sativa (NS) seed extract, and their potential for biomedical applications was investigated. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), total porosity measurements, and water contact angle measurements were used to evaluate the electrospun nanofibrous mats. Additionally, the antibacterial activities of Escherichia coli and Staphylococcus aureus were investigated, as well as cell cytotoxicity and antioxidant activity, using MTT and DPPH assays, respectively. The obtained PCL/CS/NS nanofiber mat was observed by SEM to have a homogeneous and bead-free morphology, with average diameters of 81.19 ± 4.38 nm. Contact angle measurements showed that the wettability of the electrospun PCL/Cs fiber mats decreased with the incorporation of NS when compared to the PCL/CS nanofiber mats. Efficient antibacterial activity against S. aureus and E. coli was displayed, and an in vitro cytotoxic assay demonstrated that the normal murine fibroblast cell line (L929 cells) remained viable after 24, 48, and 72 h following direct contact with the produced electrospun fiber mats. The results suggest that the PCL/CS/NS hydrophilic structure and the densely interconnected porous design are biocompatible materials, with the potential to treat and prevent microbial wound infections.
{"title":"Fabrication of a Polycaprolactone/Chitosan Nanofibrous Scaffold Loaded with <i>Nigella sativa</i> Extract for Biomedical Applications.","authors":"Qasim Shakir Kahdim, Najmeddine Abdelmoula, Hassan Al-Karagoly, Salim Albukhaty, Jabbar Al-Saaidi","doi":"10.3390/biotech12010019","DOIUrl":"https://doi.org/10.3390/biotech12010019","url":null,"abstract":"<p><p>In this study, biocompatible electrospun nanofiber scaffolds were produced using poly(-caprolactone (PCL)/chitosan (CS) and <i>Nigella sativa</i> (NS) seed extract, and their potential for biomedical applications was investigated. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), total porosity measurements, and water contact angle measurements were used to evaluate the electrospun nanofibrous mats. Additionally, the antibacterial activities of <i>Escherichia coli</i> and <i>Staphylococcus aureus</i> were investigated, as well as cell cytotoxicity and antioxidant activity, using MTT and DPPH assays, respectively. The obtained PCL/CS/NS nanofiber mat was observed by SEM to have a homogeneous and bead-free morphology, with average diameters of 81.19 ± 4.38 nm. Contact angle measurements showed that the wettability of the electrospun PCL/Cs fiber mats decreased with the incorporation of NS when compared to the PCL/CS nanofiber mats. Efficient antibacterial activity against <i>S. aureus</i> and <i>E. coli</i> was displayed, and an in vitro cytotoxic assay demonstrated that the normal murine fibroblast cell line (L929 cells) remained viable after 24, 48, and 72 h following direct contact with the produced electrospun fiber mats. The results suggest that the PCL/CS/NS hydrophilic structure and the densely interconnected porous design are biocompatible materials, with the potential to treat and prevent microbial wound infections.</p>","PeriodicalId":34490,"journal":{"name":"BioTech","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9944449/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9327260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chitosan oligomers (COS) are polysaccharides obtained by the hydrolyzation of chitosan. They are water-soluble, biodegradable, and have a wide range of beneficial properties for human health. Studies have shown that COS and its derivatives possess antitumor, antibacterial, antifungal, and antiviral activities. The goal of the current study was to investigate the anti-human immunodeficiency virus-1 (HIV-1) potential of amino acid-conjugated COS compared to COS itself. The HIV-1 inhibitory effects of asparagine-conjugated (COS-N) and glutamine-conjugated (COS-Q) COS were evaluated by their ability to protect C8166 CD4+ human T cell lines from HIV-1 infection and infection-mediated death. The results show that the presence of COS-N and COS-Q was able to prevent cells from HIV-1-induced lysis. Additionally, p24 viral protein production was observed to be suppressed in COS conjugate-treated cells compared to COS-treated and untreated groups. However, the protective effect of COS conjugates diminished by delayed treatment indicated an early stage inhibitory effect. COS-N and COS-Q did not show any inhibitory effect on the activities of HIV-1 reverse transcriptase and protease enzyme. The results suggest that COS-N and COS-Q possess an HIV-1 entry inhibition activity compared to COS and further studies to develop different peptide and amino acid conjugates containing N and Q amino acids might yield more effective compounds to battle HIV-1 infection.
{"title":"In Vitro Anti-HIV-1 Activity of Chitosan Oligomers <i>N</i>-Conjugated with Asparagine and Glutamine.","authors":"Fatih Karadeniz","doi":"10.3390/biotech12010018","DOIUrl":"https://doi.org/10.3390/biotech12010018","url":null,"abstract":"<p><p>Chitosan oligomers (COS) are polysaccharides obtained by the hydrolyzation of chitosan. They are water-soluble, biodegradable, and have a wide range of beneficial properties for human health. Studies have shown that COS and its derivatives possess antitumor, antibacterial, antifungal, and antiviral activities. The goal of the current study was to investigate the anti-human immunodeficiency virus-1 (HIV-1) potential of amino acid-conjugated COS compared to COS itself. The HIV-1 inhibitory effects of asparagine-conjugated (COS-N) and glutamine-conjugated (COS-Q) COS were evaluated by their ability to protect C8166 CD4+ human T cell lines from HIV-1 infection and infection-mediated death. The results show that the presence of COS-N and COS-Q was able to prevent cells from HIV-1-induced lysis. Additionally, p24 viral protein production was observed to be suppressed in COS conjugate-treated cells compared to COS-treated and untreated groups. However, the protective effect of COS conjugates diminished by delayed treatment indicated an early stage inhibitory effect. COS-N and COS-Q did not show any inhibitory effect on the activities of HIV-1 reverse transcriptase and protease enzyme. The results suggest that COS-N and COS-Q possess an HIV-1 entry inhibition activity compared to COS and further studies to develop different peptide and amino acid conjugates containing N and Q amino acids might yield more effective compounds to battle HIV-1 infection.</p>","PeriodicalId":34490,"journal":{"name":"BioTech","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9944945/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9327261","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cytochrome P450 (CYP) enzymes play important roles in metabolising endogenous and xenobiotic substances. Characterisations of human CYP proteins have been advanced with the rapid development of molecular technology that allows heterologous expression of human CYPs. Among several hosts, bacteria systems such as Escherichia coli (E. coli) have been widely used thanks to their ease of use, high level of protein yields, and affordable maintenance costs. However, the levels of expression in E. coli reported in the literature sometimes differ significantly. This paper aims to review several contributing factors, including N-terminal modifications, co-expression with a chaperon, selections of vectors and E. coli strains, bacteria culture and protein expression conditions, bacteria membrane preparations, CYP protein solubilizations, CYP protein purifications, and reconstitution of CYP catalytic systems. The common factors that would most likely lead to high expression of CYPs were identified and summarised. Nevertheless, each factor may still require careful evaluation for individual CYP isoforms to achieve a maximal expression level and catalytic activity. Recombinant E. coli systems have been evidenced as a useful tool in obtaining the ideal level of human CYP proteins, which ultimately allows for subsequent characterisations of structures and functions.
{"title":"Heterologous Expression of Recombinant Human Cytochrome P450 (CYP) in <i>Escherichia coli</i>: N-Terminal Modification, Expression, Isolation, Purification, and Reconstitution.","authors":"Tao Shang, Chee Mun Fang, Chin Eng Ong, Yan Pan","doi":"10.3390/biotech12010017","DOIUrl":"https://doi.org/10.3390/biotech12010017","url":null,"abstract":"<p><p>Cytochrome P450 (CYP) enzymes play important roles in metabolising endogenous and xenobiotic substances. Characterisations of human CYP proteins have been advanced with the rapid development of molecular technology that allows heterologous expression of human CYPs. Among several hosts, bacteria systems such as <i>Escherichia coli</i> (<i>E. coli</i>) have been widely used thanks to their ease of use, high level of protein yields, and affordable maintenance costs. However, the levels of expression in <i>E. coli</i> reported in the literature sometimes differ significantly. This paper aims to review several contributing factors, including N-terminal modifications, co-expression with a chaperon, selections of vectors and <i>E. coli</i> strains, bacteria culture and protein expression conditions, bacteria membrane preparations, CYP protein solubilizations, CYP protein purifications, and reconstitution of CYP catalytic systems. The common factors that would most likely lead to high expression of CYPs were identified and summarised. Nevertheless, each factor may still require careful evaluation for individual CYP isoforms to achieve a maximal expression level and catalytic activity. Recombinant <i>E. coli</i> systems have been evidenced as a useful tool in obtaining the ideal level of human CYP proteins, which ultimately allows for subsequent characterisations of structures and functions.</p>","PeriodicalId":34490,"journal":{"name":"BioTech","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9944785/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9327266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Using algal-derived mycosporine-like amino acids (MAAs) in sunscreen formulations is constrained by low cellular concentrations of MAAs and by the high costs associated with harvesting algal cells and extracting the MAAs. Here, we report an industrial scalable method using a membrane filtration approach to purify and concentrate aqueous extracts of MAAs. The method includes an additional biorefinery step enabling purification of phycocyanin, an established valuable natural product. Cultivated cells of the cyanobacterium Chlorogloeopsis fritschii (PCC 6912) were concentrated and homogenised to produce a feed for sequential processing through three membranes of decreasing pore size to obtain a retentate and permeate for each step. Microfiltration (0.2 µm) was used to remove cell debris. Ultrafiltration (10,000 Da) was used to remove large molecules and recover phycocyanin. Finally, nanofiltration (300-400 Da) was used to remove water and other small molecules. Permeate and retentate were analysed using UV-visible spectrophotometry and HPLC. The initial homogenised feed had a shinorine concentration of 5.6 ± 07 mg L-1. The final nanofiltered retentate resulted in a 3.3 times-purified concentrate (shinorine concentration of 18.71 ± 0.29 mg L-1). Significant process losses (35%) highlight scope for improvement. Results confirm the potential of membrane filtration to purify and concentrate aqueous solutions of MAAs with simultaneous separation of phycocyanin highlighting a biorefinery approach.
{"title":"Separating and Purifying Mycosporine-like Amino Acids from Cyanobacteria for Application in Commercial Sunscreen Formulations.","authors":"Valeria Candelo, Carole Anne Llewellyn","doi":"10.3390/biotech12010016","DOIUrl":"https://doi.org/10.3390/biotech12010016","url":null,"abstract":"<p><p>Using algal-derived mycosporine-like amino acids (MAAs) in sunscreen formulations is constrained by low cellular concentrations of MAAs and by the high costs associated with harvesting algal cells and extracting the MAAs. Here, we report an industrial scalable method using a membrane filtration approach to purify and concentrate aqueous extracts of MAAs. The method includes an additional biorefinery step enabling purification of phycocyanin, an established valuable natural product. Cultivated cells of the cyanobacterium <i>Chlorogloeopsis fritschii</i> (PCC 6912) were concentrated and homogenised to produce a feed for sequential processing through three membranes of decreasing pore size to obtain a retentate and permeate for each step. Microfiltration (0.2 µm) was used to remove cell debris. Ultrafiltration (10,000 Da) was used to remove large molecules and recover phycocyanin. Finally, nanofiltration (300-400 Da) was used to remove water and other small molecules. Permeate and retentate were analysed using UV-visible spectrophotometry and HPLC. The initial homogenised feed had a shinorine concentration of 5.6 ± 07 mg L<sup>-1</sup>. The final nanofiltered retentate resulted in a 3.3 times-purified concentrate (shinorine concentration of 18.71 ± 0.29 mg L<sup>-1</sup>). Significant process losses (35%) highlight scope for improvement. Results confirm the potential of membrane filtration to purify and concentrate aqueous solutions of MAAs with simultaneous separation of phycocyanin highlighting a biorefinery approach.</p>","PeriodicalId":34490,"journal":{"name":"BioTech","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9944071/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10765420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}