Process Biochemistry最新文献

Cathelicidin-RC1, extracted from the bullfrog Rana catesbeiana, has been found to effectively combat gram-negative bacteria but has limited inhibitory effects on gram-positive bacteria. Additionally, the specific mechanism of cathelicidin-RC1’s interaction with bacteria remains unclear. In this research, we present the expression analysis of a chimeric peptide composed of three repetitive units of cathelicidin-RC1 (3×cathelicidin-RC1) with a hemagglutinin (HA) and a 6×His tag attached at its C-terminus in Chlamydomonas reinhardtii, leading to the production of a chimeric peptide with a molecular mass of ~16.2 kDa. The recombinant peptide, 3×cathelicidin-RC1-HA-6×His, demonstrates a wide range of antimicrobial activity, with minimum inhibitory concentration (MIC) values of approximately 20~30 µg/ml and 10~60 µg/ml against gram-positive and negative bacteria, respectively. The minimum bactericidal concentration (MBC) values of 3×cathelicidin-RC1-HA-6×His varies from 1× to 3×MIC. Furthermore, 3×cathelicidin-RC1-HA-6×His demonstrates excellent stability, pH stability, and resistance to digestion by certain proteases. It also exhibits low cytotoxicity and negligible hemolytic activity against rat erythrocytes. Scanning electron microscopy and propidium iodide analysis indicate that 3×cathelicidin-RC1-HA-6×His disrupts bacterial cell membranes, leading to inhibition of bacterial growth. Overall, our findings demonstrate that 3×cathelicidin-RC1-HA-6×His, produced in the heterologous expression host C. reinhardtii, effectively inhibits bacterial growth and holds great promise for potential application.

Biopolymer materials have attracted attention due to their richness, sustainability, environmental friendliness, and biodegradability properties. This review explores recent advances in biopolymer synthesis, properties, and their commercial applications. Biopolymers, derived from renewable sources, have garnered significant attention due to their environmental benefits and potential to replace conventional petrochemical-based plastics. The synthesis of biopolymer delves into innovative biopolymer production techniques, including microbial fermentation, chemical modifications, and novel biotechnological approaches. A detailed examination of the unique properties of biopolymers, including physical, thermal, mechanical, and optical characteristics of naturally generated biopolymers. It explores the diverse range of applications of biopolymers across industries, including packaging for the food industry, biomedical engineering, cosmetics, and different mechanical applications. The review further discusses the growing commercial applications of biopolymers across various industries, such as packaging, agriculture, medicine, and textiles. This review aims to provide an understanding of the current method of synthesis properties and future potential application of biopolymers in advancing sustainable materials science.

Antimicrobial peptides (AMPs) belong to a group of biomolecules found in various life forms and form an important part of their defense mechanisms. They are effective against bacteria, viruses, fungi, and other parasites and have been categorized into different classes based on their structure and mode of action. Given the current global threat of increasing microbial resistance towards the diverse range of antibiotics, these AMPs represent an alternative approach to treating various infectious diseases and other bodily disorders. Their host specificity and biocompatibility with negligible resistance to various pathogens make them a much-researched substance in modern medical sciences. From screening of various natural resources to in silico design of novel AMPs, numerous AMPs have been discovered, some of which are used for commercial applications. In addition, specialized databases have been established to maintain information on these AMPs, and their fusion with other innovations, such as nanotechnology, has been accomplished. AMPs are also used in the food industry for packaging, and their application in other areas can be further explored and optimized for therapeutic purposes.

Recent advancements in cancer drug delivery have various drawbacks. To address these constraints, a new paradigm for the creation of AuNPs from microorganisms is being explored due to its cost-effectiveness, mass production capability, and substantial environmental impact. Herein, we described a facile method for biosynthesis of AuNPs employing the radiation-resistant extremophile bacterium Deinococcus radiodurans culture filtrate (cell free supernatant) as a reducing agent and capping agent in an aqueous solution without any external energy. The synthesis of AuNPs was inferred by the color change from pale red to purple that was supported by various characterization tools. The UV–visible spectrum has an absorption peak at 542 nm, which highlights the excitation and Surface Plasmon resonance of AuNPs. The FT-IR was used to examine the functionalization of the biosynthesized AuNPs. The FESEM image of AuNPs are spherical in shape and range in size from 30 to 50 nm and the AuNPs was functionalized with Polyvinylpyrrolidone and further conjugated with the targeting vehicle folate for the delivery of Quercetin. The drug release of Quercetin shows 90 % at 22 hours. Functionalized AuNPs demonstrated dose-dependent cytotoxicity in this investigation against the human breast cancer MCF-7 cell line. Furthermore, the study of apoptotic induction using the AO/EB staining approach demonstrates the obvious morphological alterations brought on by induced apoptosis. Based on the administration of Quercetin, DNA damage has been shown by DNA fragmentation analysis. AuNPs from the culture filtrate of bacterium Deinococcus radiodurans are being actively synthesized and functionalized for a targeted anticancer drug delivery system in the current work.

Melanin plays an important role in protecting skin cells from harmful UV radiation, but its uneven pigmentation in the skin sometimes demands cosmetic resolution. As a safe and effective way of evening the skin tone, enzymatic decolorization of melanin at the stratum corneum has been proposed. In this regard, the use of lignin peroxidase, in the presence of hydrogen peroxide and veratryl alcohol, an electron mediator, has been explored. Here, we first show that versatile peroxidase (VP) and aryl alcohol oxidase (AAO) purified from the Pleurotus eryngii liquid culture can be used to decolorize melanin without exogenous hydrogen peroxide. This resembles the oxidative degradation pathway of lignin in nature; AAO generates hydrogen peroxide from veratryl alcohol, and VP utilizes generated hydrogen peroxide while using veratryl alcohol as a mediator. We further explored the use of POX_Pe, the crude peroxidase preparation of the Pleurotus eryngii liquid culture, for melanin decolorization because of its better stability. Using POX_Pe and veratryl alcohol, over 60 % of melanin decolorization was obtained in 1 h in the absence of exogenous hydrogen peroxide addition. Furthermore, POX_Pe could decolorize melanin in a 3D human pigmented epidermis model, demonstrating its possible applications in cosmetics.

The elevated level of pollutants in water highlights the urgency of effective wastewater treatment. Hence, the concern about the potential of microalgae as an economically and environmentally sustainable for wastewater treatment is addressed. Wastewater treatment using microalgae resulted in significant reductions in micropollutants by 82 % for chemical oxygen demand (COD) and biological oxygen demand (BOD). Iron (Fe) concentration was reduced by 99 %, while calcium (Ca) decreased by 25 %. Algal biomass obtained from wastewater is executed for biochar production and bio-stimulant preparation. Bio-stimulant treatment significantly enhanced seed germination and increased shoot and root lengths in maize (Zea mays) and beans (Phaseolus vulgaris) compared to the control. Conversely, seed germination was completely suppressed in both maize and beans in the presence of biochar of bio-stimulant treatment. The GC-MS and NMR analysis study revealed the presence of key compounds in the microalgal extract that have a great contribution to plant growth. Hence, the study concludes the multifaceted and potential application of microalgae as a remediation and bio-stimulant in a sustainable way.

The caseinolytic protease (ClpP)-producing strain CHFM, isolated from Algerian goat milk, was identified as Lactiplantibacillus pentosus through 16 S rRNA sequence analysis. The optimal conditions for ClpP expression by Lpb. pentosus CHFM were determined in a modified MRS medium, where peptone was replaced with casein. The most favourable conditions were a pH of 8.0, a temperature between 25°C and 55°C, and an incubation period of 48 h. PCR screening and subsequent cloning and sequencing of the ClpP-encoding gene from the Lpb. pentosus CHFM genome revealed two conservative substitutions: threonine to serine at position 161, and aspartic acid to glutamic acid at position 182. Bioinformatic analysis indicated an instability index value of 40.51 for ClpP CHFM, suggesting stability, with an alpha-helix being the predominant secondary structure element, followed by a random coil. The aliphatic index was 97.60, indicating thermal stability. The GRAVY index was −0.23, suggesting enhanced interaction with water. The molecular weight was found to be 25.5 kDa with an isoelectric point (pI) of 4.78. The structural and docking analysis demonstrated that ClpP CHFM possesses the ability to hydrolyze αS1-casein.

Antimicrobial peptides have emerged as a potential alternative to combat the growing threat towards antimicrobial resistance. Owing to a large number of possible combinations of twenty naturally occurring amino acids, it is extremely resource intensive to experimentally identify whether a given peptide has desired therapeutic properties. To expedite the screening of therapeutic peptides, we propose a classification framework that can simultaneously predict the antibacterial activity, hemotoxicity, and efficacy against three most common pathogens i.e., Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa for any given peptide. The proposed framework uses support vector machine algorithm with amino acid compositions, sequence analysis, and physicochemical properties as features to develop three binary classifiers. Our models resulted in accuracies of 97.3 %, 86.2 %, and 84.1 % for antibacterial activity, combined efficacy against all three pathogens, and hemotoxicity, respectively. Explainable machine learning algorithm was implemented for each model to elucidate meaningful insights. It was evident that physicochemical properties along with the occurrence of certain amino acids play the most important role in determining antibacterial activity, efficacy, and hemolytic activity of peptides. The entire framework is made accessible freely in form of a web tool, which will further aid in rapid screening of antibacterial peptides with high therapeutic potential.

Lipopeptides have favorable biological activity and thus have great potential to serve as replacements. Whole genome sequencing was used in this work to pinpoint the gene clusters in Bacillus subtilis that code for secondary metabolites that have antibacterial qualities. Afterwards, the metabolic pathways responsible for the production of these compounds were clarified, and the lipopeptides were separated and identified using a combination of chromatography and spectroscopy methods, such as High-Performance Liquid Chromatography (HPLC), Fourier Transform Infrared Spectroscopy (FTIR), and Liquid Chromatography-Mass Spectrometry (LC-MS). Bacillus subtilis mainly synthesized surfactin homologs with carbon chain lengths ranging from C13 to C16 ([M+H]+: 994.6418; 1008.6586; 1022.6730; 1036.6896) and fengycin homologs with carbon chain lengths of C15 and C16 ([M+H]+: 1449.7937, 1463.8046). The isolated lipopeptides exhibited strong inhibitory effects against Escherichia coli and Staphylococcus aureus, with minimum inhibitory doses of 12.50 mg/L and 6.25 mg/L, respectively. Furthermore, lipopeptides demonstrated a dose-dependent inhibition of E. coli and S. aureus. The findings from SEM and SYTO 9/PI staining demonstrate that lipopeptides function by compromising the integrity of bacterial cell membranes. The results demonstrate the effectiveness of lipopeptides as antibacterial agents against foodborne pathogens, indicating their potential as substitutes for traditional antibiotics.

Oh-defensin, an antimicrobial peptide, extracted from the venom of Ornithoctonus hainana, potently inhibited fungi and Gram-negative bacteria but showed limited antibacterial potency against Gram-positive bacteria via an unknown mechanism. In this study, a recombinant peptide termed as 3×Oh-defensin-HA-6×His composed of three repeats of Oh-defensin followed by hemagglutinin (HA) and six histidine (6×His) double tags was expressed in Chlamydomonas reinhardtii. The bacteriostatic activity of 3×Oh-defensin-HA-6×His certified against both Gram-negative and Gram-positive bacteria was confirmed, with minimum inhibitory concentration (MIC) between 10 and 80 µg/mL. The minimum bactericidal concentration (MBC) was determined to range from 1× to 2×MIC. In addition, 3×Oh-defensin-HA-6×His exhibited resistance to temperature shocks, extreme pH, and proteinase digestion and it was biologically safe because it displayed low cytotoxicity and hemolysis. In addition, scanning electron microscopy (SEM) and propidium iodide (PI) staining revealed that 3×Oh-defensin-HA-6×His caused the destruction of the bacterial cell membrane, which effectively inhibited bacterial growth. In summary, our findings suggest that green algae-derived 3×Oh-defensin-HA-6×His holds significant promise as a potential alternative to conventional antibiotics in the future.