1
|
Pérez ME, Durantini JE, Martínez SR, Durantini AM, Milanesio ME, Durantini EN. Porphyrin-BODIPY Dyad: Enhancing Photodynamic Inactivation via Antenna Effect. Chembiochem 2024; 25:e202400138. [PMID: 38478375 DOI: 10.1002/cbic.202400138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 03/12/2024] [Indexed: 04/04/2024]
Abstract
A porphyrin-BODIPY dyad (P-BDP) was obtained through covalent bonding, featuring a two-segment design comprising a light-harvesting antenna system connected to an energy acceptor unit. The absorption spectrum of P-BDP resulted from an overlap of the individual spectra of its constituent parts, with the fluorescence emission of the BODIPY unit experiencing significant quenching (96 %) due to the presence of the porphyrin unit. Spectroscopic, computational, and redox investigations revealed a competition between photoinduced energy and electron transfer processes. The dyad demonstrated the capability to sensitize both singlet molecular oxygen and superoxide radical anions. Additionally, P-BDP effectively induced the photooxidation of L-tryptophan. In suspensions of Staphylococcus aureus cells, the dyad led to a reduction of over 3.5 log (99.99 %) in cell survival following 30 min of irradiation with green light. Photodynamic inactivation caused by P-BDP was also extended to the individual bacterium level, focusing on bacterial cells adhered to a surface. This dyad successfully achieved the total elimination of the bacteria upon 20 min of irradiation. Therefore, P-BDP presents an interesting photosensitizing structure that takes advantage of the light-harvesting antenna properties of the BODIPY unit combined with porphyrin, offering potential to enhance photoinactivation of bacteria.
Collapse
Affiliation(s)
- María E Pérez
- IDAS-CONICET, Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta Nacional 36 Km 601, X5804BYA, Río Cuarto, Córdoba, Argentina
| | - Javier E Durantini
- IITEMA-CONICET, Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta Nacional 36 Km 601, X5804BYA, Río Cuarto, Córdoba, Argentina
| | - Sol R Martínez
- IITEMA-CONICET, Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta Nacional 36 Km 601, X5804BYA, Río Cuarto, Córdoba, Argentina
| | - Andrés M Durantini
- Department of Chemistry, Southern Illinois University Edwardsville, Edwardsville, Illinois, 62026, United States
| | - María E Milanesio
- IDAS-CONICET, Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta Nacional 36 Km 601, X5804BYA, Río Cuarto, Córdoba, Argentina
| | - Edgardo N Durantini
- IDAS-CONICET, Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta Nacional 36 Km 601, X5804BYA, Río Cuarto, Córdoba, Argentina
| |
Collapse
|
2
|
Li Y, Wang H, Chen Y, Ding L, Ju H. In Situ Glycan Analysis and Editing in Living Systems. JACS AU 2024; 4:384-401. [PMID: 38425935 PMCID: PMC10900212 DOI: 10.1021/jacsau.3c00717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 12/15/2023] [Accepted: 12/19/2023] [Indexed: 03/02/2024]
Abstract
Besides proteins and nucleic acids, carbohydrates are also ubiquitous building blocks of living systems. Approximately 70% of mammalian proteins are glycosylated. Glycans not only provide structural support for living systems but also act as crucial regulators of cellular functions. As a result, they are considered essential pieces of the life science puzzle. However, research on glycans has lagged far behind that on proteins and nucleic acids. The main reason is that glycans are not direct products of gene coding, and their synthesis is nontemplated. In addition, the diversity of monosaccharide species and their linkage patterns contribute to the complexity of the glycan structures, which is the molecular basis for their diverse functions. Research in glycobiology is extremely challenging, especially for the in situ elucidation of glycan structures and functions. There is an urgent need to develop highly specific glycan labeling tools and imaging methods and devise glycan editing strategies. This Perspective focuses on the challenges of in situ analysis of glycans in living systems at three spatial levels (i.e., cell, tissue, and in vivo) and highlights recent advances and directions in glycan labeling, imaging, and editing tools. We believe that examining the current development landscape and the existing bottlenecks can drive the evolution of in situ glycan analysis and intervention strategies and provide glycan-based insights for clinical diagnosis and therapeutics.
Collapse
Affiliation(s)
- Yiran Li
- State
Key Laboratory of Analytical Chemistry for Life Science, School of
Chemistry and Chemical Engineering, Nanjing
University, Nanjing 210023, China
| | - Haiqi Wang
- State
Key Laboratory of Analytical Chemistry for Life Science, School of
Chemistry and Chemical Engineering, Nanjing
University, Nanjing 210023, China
| | - Yunlong Chen
- State
Key Laboratory of Analytical Chemistry for Life Science, School of
Chemistry and Chemical Engineering, Nanjing
University, Nanjing 210023, China
| | - Lin Ding
- State
Key Laboratory of Analytical Chemistry for Life Science, School of
Chemistry and Chemical Engineering, Nanjing
University, Nanjing 210023, China
- Chemistry
and Biomedicine Innovation Center (ChemBIC), Nanjing University, Nanjing 210023, China
| | - Huangxian Ju
- State
Key Laboratory of Analytical Chemistry for Life Science, School of
Chemistry and Chemical Engineering, Nanjing
University, Nanjing 210023, China
| |
Collapse
|
3
|
Sundaresan A, Cheong I. Elucidating Bacterial Spore Dynamics through Lanthanide-Enhanced Live Imaging. ACS Sens 2024; 9:789-798. [PMID: 38221734 DOI: 10.1021/acssensors.3c02083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2024]
Abstract
Identifying and distinguishing dormant and active bacterial spores are vital for biosecurity, food safety, and space exploration. Yet, there is a lack of simple, quick, and nondestructive methods to achieve this. The common Schaeffer-Fulton method is both sample-destructive and requires significant operator involvement. In this study, we employed lanthanide-beta-diketonate complexes to directly observe both dormant and germinated single spores. Staining is instantaneous and requires minimal sample processing. The complex stains areas outside the core of dormant spores, leaving the core hollow and nonfluorescent. However, upon germination, the complex enters the core, making it brightly fluorescent. This difference was noted in five bacterial species including Bacillus, Clostridium, and Clostridioides. Various lanthanides and beta-diketonates can be mixed to form a range of spore-visualizing complexes. Due to their low toxicity, these complexes allow for live imaging of single germinating spores. We demonstrate low-cost imaging using a USB microscope as well as imaging of spores in milk matrices. This method provides a valuable tool for studying bacterial spores.
Collapse
Affiliation(s)
- Ajitha Sundaresan
- Temasek Life Sciences Laboratory, National University of Singapore, 117604 Singapore
- Department of Biological Sciences, National University of Singapore, 117558 Singapore
| | - Ian Cheong
- Temasek Life Sciences Laboratory, National University of Singapore, 117604 Singapore
- Department of Biological Sciences, National University of Singapore, 117558 Singapore
| |
Collapse
|
4
|
Huang J, Sheng K, Zhang Y, Song M, Ali A, Huang T, Huang M. Inactivation Effect of Germination Combined with Cold Plasma Treatment on Bacillus licheniformis Spores. Foods 2023; 12:4319. [PMID: 38231775 DOI: 10.3390/foods12234319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 11/20/2023] [Accepted: 11/27/2023] [Indexed: 01/19/2024] Open
Abstract
Food spoilage, primarily caused by spore-forming bacteria, has become a critical concern since it results in substantial economic losses within the food industry. Past investigations have successfully identified Bacillus licheniformis as the main bacterium responsible for spoilage in roast chicken. In this study, we screened a new sterilization combination from 16 germinants and 4 cold plasma conditions, respectively. Among them, the combination of "A"GFNa-1 (composed of 60 mmol/L L-alanine, 10 mmol/L D-glucose, 10 mmol/L D-fructose, and 1 g/L NaCl) with cold plasma treatment (packed with 100% argon at 70 kV) proved effective in deactivating B. licheniformis spores, resulting in a reduction of approximately 2.1 log CFU/mL. Furthermore, we exposed the spores to different conditions: CK (no germination, no cold plasma), MF (germination only), CP (no germination, 100% argon packed, 70 kV cold plasma treatment for 3 min), and MF + CP (germination for 5 h, 100% argon packed, 70 kV cold plasma treatment for 3 min). The results of heat inactivation and dipicolinic acid (DPA) release rate demonstrated that cold plasma treatment effectively inactivated both spores and vegetative cells without inducing germination. Additionally, the reduced survival under hyperosmotic conditions and the presence of distinct red fluorescence patterns observed through confocal laser scanning microscopy (CLSM) collectively suggest that cold plasma treatment disrupts the inner membrane structure and leads to the inactivation of B. licheniformis. Overall, our findings indicate a spore clearance rate of 99.2% and suggest that the combination of efficient germinants and cold plasma treatment holds promise as a viable approach to mitigate spore contamination in the food industry.
Collapse
Affiliation(s)
- Jichao Huang
- College of Engineering, Nanjing Agricultural University, Nanjing 210095, China
| | - Kairan Sheng
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Yali Zhang
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Mengmeng Song
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Ahtisham Ali
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Tianran Huang
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Ming Huang
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| |
Collapse
|
5
|
Li J, Yang J, Xin W, Wu S, Wang X, Wang C, Zhang Z. Inactivation of Bacillus subtilis spores by a combination of high-pressure thermal treatment and potassium sorbate. Food Microbiol 2023; 115:104345. [PMID: 37567628 DOI: 10.1016/j.fm.2023.104345] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 06/21/2023] [Accepted: 07/23/2023] [Indexed: 08/13/2023]
Abstract
Combining High-pressure Thermal Treatment (HPTT) and Potassium Sorbate (PS) may have a stronger spore inactivation effect. Spores of Bacillus subtilis were subjected to HPTT at 600 MPa-65 °C/75 °C and a combination of HPTT and PS of 0.1% and 0.2% concentrations. After these treatments, different procedures and techniques were employed to investigate the spore's inactivation. The results revealed that 4.92 ± 0.05 log spores were inactivated after treatment at 600 MPa-75 °C, while 5.97 ± 0.09 log spores were inactivated when the HPTT treatment was combined with 0.2% PS. Changes in permeability of the spore's inner membrane were characterized by OD600 value and release rates of nucleic acids, protein, and dipicolinic acid (DPA). Compared with HPTT treatment at 600 MPa-75 °C, the OD600 value of spores decreased further by about 50% after treatment with a combination of HPTT and 0.2% PS. Additionally, the combined treatments resulted in a significant increase in the OD260 and OD280 values, as well as the DPA release. The spore size analysis indicated a significant decrease in the size of spores treated with a combination of HPTT at 600 MPa-75 °C and PS of 0.2% concentration. Furthermore, the flow cytometry analysis and confocal laser scanning microscopy (CLSM) analysis indicated that the inner membrane damage of spores was higher after combined treatments than that after HPTT treatment alone. A significant reduction was also found in the Na+/K+-ATPase activity after the combined treatments. Also, the FTIR analysis revealed that the combined treatments resulted in significant adverse changes in the spores' inner membrane, cell wall, cortex, and nucleic acid. Therefore, the combination of HPTT and PS has a stronger inactivation effect and can be suggested as a promising strategy for the inactivation of Bacillus subtilis spores.
Collapse
Affiliation(s)
- Jiajia Li
- College of Food Science and Engineering, Ningxia University, Yinchuan, 750021, PR China
| | - Jie Yang
- College of Food Science and Engineering, Ningxia University, Yinchuan, 750021, PR China
| | - Weishan Xin
- College of Food Science and Engineering, Ningxia University, Yinchuan, 750021, PR China
| | - Sirui Wu
- College of Food Science and Engineering, Ningxia University, Yinchuan, 750021, PR China
| | - Xujuan Wang
- College of Food Science and Engineering, Ningxia University, Yinchuan, 750021, PR China
| | - Chuanfa Wang
- College of Food Science and Engineering, Ningxia University, Yinchuan, 750021, PR China
| | - Zhong Zhang
- College of Food Science and Engineering, Ningxia University, Yinchuan, 750021, PR China.
| |
Collapse
|
6
|
Super-Resolution Microscopy and Their Applications in Food Materials: Beyond the Resolution Limits of Fluorescence Microscopy. FOOD BIOPROCESS TECH 2022. [DOI: 10.1007/s11947-022-02883-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
7
|
Recycling Food Waste and Saving Water: Optimization of the Fermentation Processes from Cheese Whey Permeate to Yeast Oil. FERMENTATION-BASEL 2022. [DOI: 10.3390/fermentation8070341] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
With the aim of developing bioprocesses for waste valorization and a reduced water footprint, we optimized a two-step fermentation process that employs the oleaginous yeast Cutaneotrichosporon oleaginosus for the production of oil from liquid cheese whey permeate. For the first step, the addition of urea as a cost-effective nitrogen source allowed an increase in yeast biomass production. In the second step, a syrup from candied fruit processing, another food waste supplied as carbon feeding, triggered lipid accumulation. Consequently, yeast lipids were produced at a final concentration and productivity of 38 g/L and 0.57 g/L/h respectively, which are among the highest reported values. Through this strategy, based on the valorization of liquid food wastes (WP and mango syrup) and by recovering not only nutritional compounds but also the water necessary for yeast growth and lipid production, we addressed one of the main goals of the circular economy. In addition, we set up an accurate and fast-flow cytometer method to quantify the lipid content, avoiding the extraction step and the use of solvents. This can represent an analytical improvement to screening lipids in different yeast strains and to monitoring the process at the single-cell level.
Collapse
|
8
|
Biochemical, microbiological, and structural evaluations to early detect age gelation of milk caused by proteolytic activity of Pseudomonas fluorescens. Eur Food Res Technol 2022. [DOI: 10.1007/s00217-022-04033-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AbstractHeat–stable peptidase AprX, released by Pseudomonas species in raw milk during cold storage, can cause gelation of UHT milk since it is able to split caseinomacropeptides (CMPtot) from κ-casein, so inducing aggregation of casein micelles. Identifying raw milk susceptibility to gelation would allow UHT milk manufacturers to select appropriate processing conditions or give the milk a different destination. Two approaches, i.e., detection of free CMPtot and evidence of casein aggregates, were evaluated as possible indicators for early detecting milk destabilization. With this aim, microfiltered milk was inoculated with a P. fluorescence strain and incubated at either 4 or 25 °C. The presence of CMPtot was detected using capillary electrophoresis after 96 and 24 h at the two temperatures, respectively, when milk also became heat unstable and small flocks of protein appeared. Confocal laser scanning microscopy evidenced initial aggregates of casein micelles after 48 and 24 h at 4 and 25 °C, respectively. Keeping the milk at 25 °C/24 h could be a useful condition to accelerate milk destabilization. Despite the similar timing of instability detection, presence of CMPtot was the only trait specific for AprX activity.
Collapse
|
9
|
Abstract
Microscopy is often used to assist the development of cheese products, but manufacturers can benefit from a much broader application of these techniques to assess structure formation during processing and structural changes during storage. Microscopy can be used to benchmark processes, optimize process variables, and identify critical control points for process control. Microscopy can also assist the reverse engineering of desired product properties and help troubleshoot production problems to improve cheese quality. This approach can be extended using quantitative analysis, which enables further comparisons between structural features and functional measures used within industry, such as cheese meltability, shreddability, and stretchability, potentially allowing prediction and control of these properties. This review covers advances in the analysis of cheese microstructure, including new techniques, and outlines how these can be applied to understand and improve cheese manufacture.
Collapse
Affiliation(s)
- Lydia Ong
- Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, Australia; .,Dairy Innovation Hub, Department of Chemical Engineering, The University of Melbourne, Parkville, Victoria, Australia
| | - Xu Li
- Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, Australia;
| | - Adabelle Ong
- Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, Australia; .,Dairy Innovation Hub, Department of Chemical Engineering, The University of Melbourne, Parkville, Victoria, Australia
| | - Sally L Gras
- Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, Australia; .,Dairy Innovation Hub, Department of Chemical Engineering, The University of Melbourne, Parkville, Victoria, Australia
| |
Collapse
|
10
|
Zhang J, Cheng X, Chang L, Zhang L, Zhang S. Combined treatments of chitosan and sodium silicate to inhibit Alternaria alternata pathogens of postharvest winter jujube. Food Sci Biotechnol 2021; 30:589-597. [PMID: 33936851 DOI: 10.1007/s10068-021-00890-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 01/26/2021] [Accepted: 02/15/2021] [Indexed: 10/21/2022] Open
Abstract
Alternaria alternata is a pathogenic fungus that infects jujube fruit and leads to serious economic losses. In this paper, the antifungal activity of chitosan combined with sodium silicate against A. alternata in vitro and in vivo was investigated, and the possible antimicrobial mechanisms were explored. Results showed that the spore germination and colony expansion of A. alternata were significantly inhibited by chitosan. Chitosan treatment induced the leakages of intercellular electrolytes, nucleic acids, and soluble protein of A. alternata. Meanwhile, chitosan damaged the cell morphology and membrane integrity of A. alternata. The combination of chitosan and sodium silicate was more effective than chitosan alone. In addition, the effect of chitosan and sodium silicate could significantly decrease natural rot rate and delay lesion expansion of winter jujube. Collectively, chitosan combined with sodium silicate had the potential to control postharvest diseases of fruit caused by A. alternata.
Collapse
Affiliation(s)
- Jingru Zhang
- College of Food Science, Shanxi Normal University, 1 Gongyuan Street, Yaodu District, Linfen, 041004 Shanxi China
| | - Xiaowen Cheng
- College of Food Science, Shanxi Normal University, 1 Gongyuan Street, Yaodu District, Linfen, 041004 Shanxi China
| | - Lulu Chang
- College of Food Science, Shanxi Normal University, 1 Gongyuan Street, Yaodu District, Linfen, 041004 Shanxi China
| | - Lele Zhang
- College of Food Science, Shanxi Normal University, 1 Gongyuan Street, Yaodu District, Linfen, 041004 Shanxi China
| | - Shaoying Zhang
- College of Food Science, Shanxi Normal University, 1 Gongyuan Street, Yaodu District, Linfen, 041004 Shanxi China
| |
Collapse
|
11
|
"Sporotan" a new fluorescent stain for identifying cryptic spores of Rhodobacter johrii. J Microbiol Methods 2020; 177:106019. [PMID: 32805369 DOI: 10.1016/j.mimet.2020.106019] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 07/21/2020] [Accepted: 07/23/2020] [Indexed: 11/27/2022]
Abstract
We propose a new fluorescent stain "sporotan" and staining protocol which aid in the identification of cryptic endospores which are otherwise mistaken as poly-β-hydroxyalkanoate granules.
Collapse
|
12
|
Senthilnathan N, Gaurav K, Venkata Ramana C, Radhakrishnan TP. Zwitterionic small molecule based fluorophores for efficient and selective imaging of bacterial endospores. J Mater Chem B 2020; 8:4601-4608. [PMID: 32391841 DOI: 10.1039/d0tb00470g] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In the emerging scenario of increasing antibiotic resistance and pathogen transmission channels, the grave danger posed by bacterial endospores in critical fields like food industry, health and medicine highlights the urgent need to develop efficient probes for their detection; their sturdy and impermeable multilayer coat makes desirable methods like fluorescence imaging extremely difficult. Selective imaging of the endospores in the presence of the bacteria is even more challenging. Furthermore, it is preferable to maintain the dormant state of endospores through the imaging process, if extended monitoring is required; many of the available techniques involve lethal germination or destruction of the endospores. We show that simple zwitterionic diaminodicyanoquinodimethane (DADQ) molecules with selected functionalities are efficient dyes for fluorescence imaging due to their dipolar structure that facilitates the penetration into the endospore system, and the enhanced fluorescence in their rigid/aggregated state. The facile structural tailorability allows DADQs with various appendage moieties to be synthesized; a derivative with ionic substituents (BT2), and another with optimally long alkyl chains and the resultant hydrophobic character (BHADQ) are shown to be excellent fluorescent probes for endospores. Nanomolar amounts of dyes provide effective staining; while BT2 stains bacteria and endospores, most significantly, BHADQ stains endospores selectively. To the best of our knowledge, this is the first example of selective fluorescence imaging of endospores in their dormant state. A range of spectroscopy, microscopy and calorimetry studies provide insight into the molecular level interactions that enable efficient staining and bright images. DADQ fluorophores are photostable and non-cytotoxic, hence useful in practical applications. The versatile structural tailorability of these dye molecules holds great promise for targeted imaging.
Collapse
Affiliation(s)
- N Senthilnathan
- School of Chemistry, University of Hyderabad, Hyderabad - 500 046, India.
| | | | | | | |
Collapse
|
13
|
Impact of Extending Hard-Cheese Ripening: A Multiparameter Characterization of Parmigiano Reggiano Cheese Ripened up to 50 Months. Foods 2020; 9:foods9030268. [PMID: 32131400 PMCID: PMC7143483 DOI: 10.3390/foods9030268] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 02/18/2020] [Accepted: 02/26/2020] [Indexed: 12/23/2022] Open
Abstract
Extending ripening of hard cheeses well beyond the traditional ripening period is becoming increasingly popular, although little is known about the actual evolution of their characteristics. The present work aimed at investigating selected traits of Parmigiano Reggiano cheese ripened for 12, 18, 24, 30, 40 and 50 months. Two cheeses per each ripening period were sampled. Although moisture constantly decreased and was close to 25% in 50-month cheeses, with a parallel increase in cheese hardness, several biochemical changes occurred involving the activity of both native and microbial enzymes. Capillary electrophoresis demonstrated degradation of αs1- and β-casein, indicating residual activity of both chymosin and plasmin. Similarly, continuous release of free amino acids supported the activity of peptidases deriving from lysed bacterial cells. Volatile flavor compounds, such as short-chain fatty acids and some derived ketones, alcohols and esters, evaluated by gas chromatography with solid-phase micro-extraction, accumulated as well. Cheese microstructure was characterized by free fat trapped in irregularly shaped areas within a protein network, with native fat globules being no longer visible. This study showed for the first time that numerous biochemical and structural variations still occur in a hard cheese at up to 50 months of aging, proving that the ripening extension deserves to be highlighted to the consumer and may justify a premium price.
Collapse
|
14
|
Evaluation of methods for DNA extraction from Clostridium tyrobutyricum spores and its detection by qPCR. J Microbiol Methods 2019; 169:105818. [PMID: 31881287 DOI: 10.1016/j.mimet.2019.105818] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 12/16/2019] [Accepted: 12/24/2019] [Indexed: 12/18/2022]
Abstract
Clostridium tyrobutyricum is the major agent that causes the blowing defect in cheese due to the germination of its dormant spores during the ripening stage. As a result, many of the affected cheeses show cavities and cracks, which cause the product loss in most cases. Nowadays, there is not a fast method capable of detecting milk contaminated with C. tyrobutyricum spores. The aim of this study has been to develop a fast and reliable method based on real time PCR (qPCR) to detect C. tyrobutyricum spores in raw milk. One of the main limitations has been to find a good procedure for the spore disruption to extract the DNA due to its high resistance. For this reason, different disruption methods have been tested, including chemical agents, bead beating, enzymatic and microwave treatment. Furthermore, an enzymatic treatment with subtilisin was applied for milk clarification and recovery of spores. The comparison of the assayed methods has been made using sterile milk spiked with C. tyrobutyricum spores, obtained in solid or liquid medium. The results showed that microwave treatment followed by a standard DNA purification step was found to be the best disruption method. The Ct values obtained for spores were higher than those found for vegetative cells by qPCR, for the same quantity of DNA. This difference could be due to the action of the Small Acid Soluble Proteins (SASP) in the DNA packaging of spores. Moreover, spores obtained in agar plate were found more resistant to disruption than those obtained in liquid medium. Subtilisin and microwave treatments were found to be successful for DNA extraction from C. tyrobutyricum spores in milk and subsequent identification by qPCR. However, the differences observed between the amplification of DNA from spores obtained in different media and from vegetative cells have to be taken into account to optimize a method for C. tyrobutyricum detection.
Collapse
|
15
|
Heredia DA, Martínez SR, Durantini AM, Pérez ME, Mangione MI, Durantini JE, Gervaldo MA, Otero LA, Durantini EN. Antimicrobial Photodynamic Polymeric Films Bearing Biscarbazol Triphenylamine End-Capped Dendrimeric Zn(II) Porphyrin. ACS APPLIED MATERIALS & INTERFACES 2019; 11:27574-27587. [PMID: 31310503 DOI: 10.1021/acsami.9b09119] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
A novel biscarbazol triphenylamine end-capped dendrimeric zinc(II) porphyrin (DP 5) was synthesized by click chemistry. This compound is a cruciform dendrimer that bears a nucleus of zinc(II) tetrapyrrolic macrocycle substituted at the meso positions by four identical substituents. These are formed by a tetrafluorophenyl group that possesses a triazole unit in the para position. This nitrogenous heterocyclic is connected to a 4,4'-di(N-carbazolyl)triphenylamine group by means of a phenylenevinylene bridge, which allows the conjugation between the nucleus and this external electropolymerizable carbazoyl group. In this structure, dendrimeric arms act as light-harvesting antennas, increasing the absorption of blue light, and as electroactive moieties. The electrochemical oxidation of the carbazole groups contained in the terminal arms of the DP 5 was used to obtain novel, stable, and reproducible fully π-conjugated photoactive polymeric films (FDP 5). First, the spectroscopic characteristics and photodynamic properties of DP 5 were compared with its constitutional components derived of porphyrin P 6 and carbazole D 7 moieties in solution. The fluorescence emissions of the dendrimeric units in DP 5 were more strongly quenched by the tetrapyrrolic macrocycle, indicating photoinduced energy transfer. In addition, FDP 5 film showed the Soret and Q absorption bands and red fluorescence emission of the corresponding zinc(II) porphyrin. Also, FDP 5 film was highly stable to photobleaching, and it was able to produce singlet molecular oxygen in both N,N-dimethylformamide (DMF) and water. Therefore, the porphyrin units embedded in the polymeric matrix of FDP 5 film mainly retain the photochemical properties. Photodynamic inactivation mediated by FDP 5 film was investigated in Staphylococcus aureus and Escherichia coli. When a cell suspension was deposited on the surface, complete eradication of S. aureus and a 99% reduction in E. coli survival were found after 15 and 30 min of irradiation, respectively. Also, FDP 5 film was highly effective to eliminate individual bacteria attached to the surface. In addition, photodynamic inactivation (PDI) sensitized by FDP 5 film produced >99.99% bacterial killing in biofilms formed on the surface after 60 min irradiation. The results indicate that FDP 5 film represents an interesting and versatile photodynamic active material to eradicate bacteria as planktonic cells, individual attached microbes, or biofilms.
Collapse
Affiliation(s)
- Daniel A Heredia
- IDAS-CONICET, Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales , Universidad Nacional de Río Cuarto , Ruta Nacional 36 Km 601 , X5804BYA Río Cuarto, Córdoba , Argentina
| | - Sol R Martínez
- IDAS-CONICET, Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales , Universidad Nacional de Río Cuarto , Ruta Nacional 36 Km 601 , X5804BYA Río Cuarto, Córdoba , Argentina
| | - Andrés M Durantini
- IDAS-CONICET, Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales , Universidad Nacional de Río Cuarto , Ruta Nacional 36 Km 601 , X5804BYA Río Cuarto, Córdoba , Argentina
| | - M Eugenia Pérez
- IDAS-CONICET, Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales , Universidad Nacional de Río Cuarto , Ruta Nacional 36 Km 601 , X5804BYA Río Cuarto, Córdoba , Argentina
| | - María I Mangione
- IQUIR-CONICET, Facultad de Ciencias Bioquímicas y Farmacéuticas , Universidad Nacional de Rosario , Suipacha 531 , S2002LRK Rosario , Argentina
| | - Javier E Durantini
- IITEMA-CONICET, Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales , Universidad Nacional de Río Cuarto , Ruta Nacional 36 Km 601 , X5804BYA Río Cuarto, Córdoba , Argentina
| | - Miguel A Gervaldo
- IITEMA-CONICET, Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales , Universidad Nacional de Río Cuarto , Ruta Nacional 36 Km 601 , X5804BYA Río Cuarto, Córdoba , Argentina
| | - Luis A Otero
- IITEMA-CONICET, Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales , Universidad Nacional de Río Cuarto , Ruta Nacional 36 Km 601 , X5804BYA Río Cuarto, Córdoba , Argentina
| | - Edgardo N Durantini
- IDAS-CONICET, Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales , Universidad Nacional de Río Cuarto , Ruta Nacional 36 Km 601 , X5804BYA Río Cuarto, Córdoba , Argentina
| |
Collapse
|