Screening and Characterization of the Diversity of Food Microorganisms and Their Metabolites 2022

A special issue of Microorganisms (ISSN 2076-2607). This special issue belongs to the section "Food Microbiology".

Deadline for manuscript submissions: closed (31 May 2023) | Viewed by 39535

Special Issue Editors


E-Mail Website
Guest Editor
Laboratory for Process Engineering, Environment, Biotechnology and Energy (LEPABE), Department of Chemical Engineering (DEQ), Faculty of Engineering, University of Porto (FEUP), Porto, Portugal
Interests: food microbiota; chromatography and mass spectrometry; separation processes; valorisation of agro-food by-products; fermentation processes and microbial starter cultures; sourdough and breadmaking
Special Issues, Collections and Topics in MDPI journals

E-Mail Website
Guest Editor
Institute of Functional Biology and Genomics (IBFG), Salamanca, Spain
Interests: yeasts genetics and molecular biology; industrial yeasts; new starters for bread and wine making; yeast hybrids; microbiomes of fermented doughs, vineyards and wines
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

This is a comprehensive Special Issue covering virtually all scientific lines of food microbiology. Topics include the prospection of microbial species in food and feed matrixes and their genotypic and phenotypic characterization, the contribution of beneficial strains, innovative fermentation and technological procedures towards nutritional and health attributes of food, and the exploitation of microbial metabolites.

Culture-dependent and independent techniques for systematic analyses of bacterial and fungal microbiomes are to be considered. The screening and characterization of food spoilage microorganisms, and its potential risks and effects on consumers is another subject to be included in this Special Issue. Topics related to the role of fermentation and the potential of encrypted phenotypic traits of microorganisms towards food hygiene, safety, and resistance to microbial spoilage are welcome. The elucidation of microbial dynamics and relationships with biotic and abiotic factors are of interest. The contribution of beneficial microorganisms, starter cultures, and innovative fermentation and processing technologies to the nutritional, technological, and health attributes of food should be highlighted in this Special Issue. The identification, characterization, and production of functional microbial substances during fermentation or by elected microorganisms will be highly relevant to designing breakthrough metabolites for food, feed, nutraceutical, cosmetic and pharmaceutical industries, and the elucidation of the corresponding metabolic pathways and optimal growth conditions.

Dr. João Miguel F. Rocha
Dr. Mercedes Tamame
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Microorganisms is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Benefits of Publishing in a Special Issue

  • Ease of navigation: Grouping papers by topic helps scholars navigate broad scope journals more efficiently.
  • Greater discoverability: Special Issues support the reach and impact of scientific research. Articles in Special Issues are more discoverable and cited more frequently.
  • Expansion of research network: Special Issues facilitate connections among authors, fostering scientific collaborations.
  • External promotion: Articles in Special Issues are often promoted through the journal's social media, increasing their visibility.
  • e-Book format: Special Issues with more than 10 articles can be published as dedicated e-books, ensuring wide and rapid dissemination.

Further information on MDPI's Special Issue polices can be found here.

Related Special Issue

Published Papers (12 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Editorial

Jump to: Research, Review

4 pages, 188 KiB  
Editorial
Diversity of Microorganisms and Their Metabolites in Food
by João Miguel Rocha, Biljana Kovacevik, Sanja Kostadinović Veličkovska, Mercedes Tamame and José António Teixeira
Microorganisms 2024, 12(1), 205; https://doi.org/10.3390/microorganisms12010205 - 19 Jan 2024
Cited by 2 | Viewed by 1180
Abstract
Throughout history as well as the present, food microorganisms have been proven to play a significant role in human life [...] Full article
5 pages, 225 KiB  
Editorial
Screening and Characterization of the Diversity of Food Microorganisms and Their Metabolites
by João Miguel Rocha, Biljana Kovacevik, Sanja Kostadinović Veličkovska, Mercedes Tamame and José António Teixeira
Microorganisms 2023, 11(5), 1235; https://doi.org/10.3390/microorganisms11051235 - 8 May 2023
Viewed by 1523
Abstract
Food is rarely kept in a sterile environment and the composition of microbial associations found in various foodstuffs is widely varied. Microorganisms in food usually originate from the natural microbiota of raw materials and the surrounding environments. Whether a species prevails depends upon [...] Read more.
Food is rarely kept in a sterile environment and the composition of microbial associations found in various foodstuffs is widely varied. Microorganisms in food usually originate from the natural microbiota of raw materials and the surrounding environments. Whether a species prevails depends upon its ability to adapt to intrinsic factors associated with foods, such as nutrient content; pH; water activity; oxidation–reduction potential; and antimicrobial properties, with various extrinsic factors playing a role, including temperature, relative humidity, atmosphere, and ambient pressure. Any change to these parameters may cause changes in the present microbial consortia. Therefore, it is important to identify which microbial consortia will thrive in particular foods and conditions. While active, microorganisms undergo many complex mechanisms that affect food quality and safety. Most beneficial food microorganisms belong to lactic acid bacteria and yeasts. Pathogenic and spoilage bacteria are usually Gram-negative, although there are some Gram-positive ones, such as Listeria monocytogenes, Clostridium botulinum, and C. perfringens. Some may merely cause spoilage, while others may be related to foodborne illnesses. Full article

Research

Jump to: Editorial, Review

13 pages, 1479 KiB  
Article
Effect of Lactiplantibacillus plantarum on the Conversion of Linoleic Acid of Vegetable Oil to Conjugated Linoleic Acid, Lipolysis, and Sensory Properties of Cheddar Cheese
by Awais Khan, Muhammad Nadeem, Fahad Al-Asmari, Muhammad Imran, Saadia Ambreen, Muhammad Abdul Rahim, Sadaf Oranab, Tuba Esatbeyoglu, Elena Bartkiene and João Miguel Rocha
Microorganisms 2023, 11(10), 2613; https://doi.org/10.3390/microorganisms11102613 - 23 Oct 2023
Cited by 3 | Viewed by 1457
Abstract
Conjugated linoleic acid (CLA) is perceived to protect the body from metabolic diseases. This study was conducted to determine the effect of Lactiplantibacillus plantarum (Lp. plantarum) on CLA production and sensory characteristics of cheddar cheese. Lp. plantarum can convert linoleic acid [...] Read more.
Conjugated linoleic acid (CLA) is perceived to protect the body from metabolic diseases. This study was conducted to determine the effect of Lactiplantibacillus plantarum (Lp. plantarum) on CLA production and sensory characteristics of cheddar cheese. Lp. plantarum can convert linoleic acid (LA) to CLA. To increase CLA in cheddar cheese and monitor the conversion of LA to CLA by Lp. plantarum, the LA content of cheese milk (3.4% fat) was increased by partially replacing fat with safflower oil (85% LA of oil) at 0, 3, 6, and 9% concentrations (T1, T2, T3, and T4). Furthermore, Lp. plantarum 108 colony-forming units (CFU)/mL (8 log CFU mL−1) was added in all treatments along with traditional cheddar cheese culture (Lactococcus lactis ssp. lactis and L. lactis ssp. cremoris). After 30 days of ripening, Lp. plantarum in T1, T2, T3, and T4 was 6.75, 6.72, 6.65, and 6.55 log CFU g−1. After 60 days of ripening, Lp. plantarum in T1, T2, T3, and T4 was 6.35, 6.27, 6.19, and 6.32 log CFU g−1. After 60 days of ripening, Lp. plantarum in T1, T2, T3, and T4 was 6.41, 6.25, 6.69, and 6.65 log CFU g−1. GC-MS analysis showed that concentrations of CLA in the 90 days’ control, T1, T2, T3, and T4 were 1.18, 2.73, 4.44, 6.24, and 9.57 mg/100 g, respectively. HPLC analysis revealed that treatments containing Lp. plantarum and LA presented higher concentrations of organic acids than the control sample. The addition of safflower oil at all concentrations did not affect cheese composition, free fatty acids (FFA), and the peroxide value (POV) of cheddar cheese. Color flavor and texture scores of experimental cheeses were not different from the control cheese. It was concluded that Lp. plantarum and safflower oil can be used to increase CLA production in cheddar cheese. Full article
Show Figures

Figure 1

15 pages, 334 KiB  
Article
Effect of Growth Stages and Lactic Acid Fermentation on Anti-Nutrients and Nutritional Attributes of Spinach (Spinacia oleracea)
by Adila Naseem, Saeed Akhtar, Tariq Ismail, Muhammad Qamar, Dur-e-shahwar Sattar, Wisha Saeed, Tuba Esatbeyoglu, Elena Bartkiene and João Miguel Rocha
Microorganisms 2023, 11(9), 2343; https://doi.org/10.3390/microorganisms11092343 - 19 Sep 2023
Cited by 4 | Viewed by 2029
Abstract
Spinach (Spinacia oleracea) is a winter-season green, leafy vegetable grown all over the world, belonging to the family Amaranthus, sub-family Chenopodiaceae. Spinach is a low-caloric food and an enormous source of micronutrients, e.g., calcium, folates, zinc, retinol, iron, ascorbic [...] Read more.
Spinach (Spinacia oleracea) is a winter-season green, leafy vegetable grown all over the world, belonging to the family Amaranthus, sub-family Chenopodiaceae. Spinach is a low-caloric food and an enormous source of micronutrients, e.g., calcium, folates, zinc, retinol, iron, ascorbic acid and magnesium. Contrarily, it also contains a variety of anti-nutritional factors, e.g., alkaloids, phytates, saponins, oxalates, tannins and many other natural toxicants which may hinder nutrient-absorption. This study was aimed at investigating the effect of fermentation on improving the nutrient-delivering potential of spinach and mitigating its burden of antinutrients and toxicants at three growth stages: the 1st growth stage as baby leaves, the 2nd growth stage at the coarse stage, and the 3rd growth stage at maturation. The results revealed the significant (p < 0.05) effect of fermentation on increasing the protein and fiber content of spinach powder from 2.53 to 3.53% and 19.33 to 22.03%, respectively, and on reducing total carbohydrate content from 52.92 to 40.52%; the effect was consistent in all three growth stages. A significant decline in alkaloids (6.45 to 2.20 mg/100 g), oxalates (0.07 mg/100 g to 0.02 mg/100 g), phytates (1.97 to 0.43 mg/100 g) and glucosinolates (201 to 10.50 µmol/g) was observed as a result of fermentation using Lactiplantibacillus plantarum. Fermentation had no impact on total phenolic content and the antioxidant potential of spinach, as evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric-reducing antioxidant power (FRAP) assays. This study proposes fermentation as a safer bioprocess for improving the nutrient-delivering potential of spinach, and suggests processed powders made from spinach as a cost-effective complement to existing plant proteins. Full article
15 pages, 2752 KiB  
Article
Kosakonia cowanii Ch1 Isolated from Mexican Chili Powder Reveals Growth Inhibition of Phytopathogenic Fungi
by Jacqueline González Espinosa, Yoali Fernanda Hernández Gómez, Yomaiko Javier Martínez, Francisco Javier Flores Gallardo, Juan Ramiro Pacheco Aguilar, Miguel Ángel Ramos López, Jackeline Lizzeta Arvizu Gómez, Carlos Saldaña Gutierrez, José Alberto Rodríguez Morales, María Carlota García Gutiérrez, Aldo Amaro Reyes, Erika Álvarez Hidalgo, Jorge Nuñez Ramírez, José Luis Hernández Flores and Juan Campos Guillén
Microorganisms 2023, 11(7), 1758; https://doi.org/10.3390/microorganisms11071758 - 5 Jul 2023
Cited by 3 | Viewed by 2792
Abstract
Kosakonia cowanii strain Ch1 was isolated from Mexican chili powder, and the genome was sequenced. The genome was 4,765,544 bp in length, with an average G + C content of 56.22%, and a plasmid (pCh1) of 128,063 bp with an average G + [...] Read more.
Kosakonia cowanii strain Ch1 was isolated from Mexican chili powder, and the genome was sequenced. The genome was 4,765,544 bp in length, with an average G + C content of 56.22%, and a plasmid (pCh1) of 128,063 bp with an average G + C content of 52.50%. A phylogenetic analysis revealed a close relation with pathogenic strains; nevertheless, some virulence-related genes were absent, and this genetic characteristic may explain the fact that K. cowanii Ch1 behaved as a non-pathogenic strain when infection assays were performed on the leaves and fruits of Capsicum annuum L. Surprisingly, we observed that this bacterial strain had the ability to spread throughout serrano pepper seeds. Furthermore, K. cowanii Ch1 was evaluated for the production of volatile organic compounds (VOCs) against fungal pathogens, and the results showed that Alternaria alternata and Sclerotium rolfsii were inhibited in a radial mycelial growth assay by a mean rate of 70% and 64%, while Fusarium oxysporum was inhibited by only approximately 10%. Based on the headspace solid-phase microextraction combined with the gas chromatography mass spectrometry (HS-SPME-GC-MS), 67 potential VOCs were identified during the fermentation of K. cowanii Ch1 in TSA medium. From these VOCs, nine main compounds were identified based on relative peak area: dodecanoic acid; 3-hydroxy ethanol; 1-butanol-3-methyl; acetaldehyde; butanoic acid, butyl ester; cyclodecane; 2-butanone, 3-hydroxy; disulfide, dimethyl and pyrazine-2,5-dimethyl. Our findings show the potential of K. cowanii Ch1 for the biocontrol of fungal pathogens through VOCs production and reveal additional abilities and metabolic features as beneficial bacterial specie. Full article
Show Figures

Figure 1

15 pages, 1855 KiB  
Article
The Effect of Oil-Rich Food Waste Substrates, Used as an Alternative Carbon Source, on the Cultivation of Microalgae—A Pilot Study
by Pavlína Sniegoňová, Martin Szotkowski, Jiří Holub, Pavlína Sikorová and Ivana Márová
Microorganisms 2023, 11(7), 1621; https://doi.org/10.3390/microorganisms11071621 - 21 Jun 2023
Cited by 2 | Viewed by 1723
Abstract
Microalgae are mostly phototrophic microorganisms present worldwide, showcasing great adaptability to their environment. They are known for producing essential metabolites such as carotenoids, chlorophylls, sterols, lipids, and many more. This study discusses the possibility of the mixotrophic abilities of microalgae in the presence [...] Read more.
Microalgae are mostly phototrophic microorganisms present worldwide, showcasing great adaptability to their environment. They are known for producing essential metabolites such as carotenoids, chlorophylls, sterols, lipids, and many more. This study discusses the possibility of the mixotrophic abilities of microalgae in the presence of food waste oils. The utilization of food waste materials is becoming more popular as a research subject as its production grows every year, increasing the environmental burden. In this work, waste frying oil and coffee oil were tested for the first time as a nutrition source for microalgae cultivation. Waste frying oil is produced in large amounts all over the world and its simple purification is one of its greatest advantages as it only needs to be filtered from leftover food pieces. Coffee oil is extracted from waste spent coffee grounds as a by-product. The waste frying oil and coffee oil were added to the basic algal media as an alternative source of carbon. As a pilot study for further experimentation, the effect of oil in the medium, algal adaptability, and capability to survive were tested within these experiments. The growth and production characteristics of four algae and cyanobacteria strains were tested, of which the strain Desmodesmus armatus achieved exceptional results of chlorophyll (8.171 ± 0.475 mg/g) and ubiquinone (5.708 ± 0.138 mg/g) production. The strain Chlamydomonas reindhartii showed exceptional lipid accumulation in the range of 30–46% in most of the samples. Full article
Show Figures

Figure 1

15 pages, 2031 KiB  
Article
16S-rRNA-Based Metagenomic Profiling of the Bacterial Communities in Traditional Bulgarian Sourdoughs
by Vesselin Baev, Elena Apostolova, Velitchka Gotcheva, Miglena Koprinarova, Maria Papageorgiou, João Miguel Rocha, Galina Yahubyan and Angel Angelov
Microorganisms 2023, 11(3), 803; https://doi.org/10.3390/microorganisms11030803 - 21 Mar 2023
Cited by 4 | Viewed by 2165
Abstract
Sourdoughs (SDs) are spontaneously formed microbial ecosystems composed of various species of lactic acid bacteria (LAB) and acid-tolerant yeasts in food matrices of cereal flours mixed with water. To date, more than 90 LAB species have been isolated, significantly impacting the organoleptic characteristics, [...] Read more.
Sourdoughs (SDs) are spontaneously formed microbial ecosystems composed of various species of lactic acid bacteria (LAB) and acid-tolerant yeasts in food matrices of cereal flours mixed with water. To date, more than 90 LAB species have been isolated, significantly impacting the organoleptic characteristics, shelf life, and health properties of bakery products. To learn more about the unique bacterial communities involved in creating regional Bulgarian sourdoughs, we examined the metacommunities of five sourdoughs produced by spontaneous fermentation and maintained by backslopping in bakeries from three geographic locations. The 16S rRNA gene amplicon sequencing showed that the former genus Lactobacillus was predominant in the studied sourdoughs (51.0–78.9%). Weissella (0.9–42.8%), Herbaspirillum (1.6–3.8%), Serratia (0.1–11.7%), Pediococcus (0.2–7.5%), Bacteroides (0.1–1.3%), and Sphingomonas (0.1–0.5%) were also found in all 5 samples. Genera Leuconostoc, Enterococcus, Bacillus, and Asaia were sample-specific. It is interesting to note that the genus Weissella was more abundant in wholegrain samples. The greatest diversity at the species level was found in the former genus Lactobacillus, presented in the sourdough samples with 13 species. The UPGMA cluster analysis clearly demonstrated similarity in species’ relative abundance between samples from the same location. In addition, we can conclude that the presence of two main clusters—one including samples from mountainous places (the cities of Smolyan and Bansko) and the other including samples from the city of Ruse (the banks of the Danube River)—may indicate the impact of climate and geographic location (e.g., terrain, elevation, land use, and nearby water bodies and their streams) on the abundance of microbiome taxa. As the bacterial population is crucial for bread standardization, we expect the local bakery sector to be interested in the relationship between process variables and their effect on bacterial dynamics described in this research study. Full article
Show Figures

Figure 1

11 pages, 473 KiB  
Article
Maximizing Laboratory Production of Aflatoxins and Fumonisins for Use in Experimental Animal Feeds
by Phillis E. Ochieng, David C. Kemboi, Marie-Louise Scippo, James K. Gathumbi, Erastus Kangethe, Barbara Doupovec, Siska Croubels, Johanna F. Lindahl, Gunther Antonissen and Sheila Okoth
Microorganisms 2022, 10(12), 2385; https://doi.org/10.3390/microorganisms10122385 - 30 Nov 2022
Cited by 3 | Viewed by 2210
Abstract
Warm and humid climatic conditions coupled with poor agricultural practices in sub-Saharan Africa favor the contamination of food and feed by Aspergillus flavus and Fusarium verticillioides fungi, which subsequently may produce aflatoxins (AFs) and fumonisins (FBs), respectively. The growth of fungi and the [...] Read more.
Warm and humid climatic conditions coupled with poor agricultural practices in sub-Saharan Africa favor the contamination of food and feed by Aspergillus flavus and Fusarium verticillioides fungi, which subsequently may produce aflatoxins (AFs) and fumonisins (FBs), respectively. The growth of fungi and the production of mycotoxins are influenced by physical (temperature, pH, water activity, light and aeration), nutritional, and biological factors. This study aimed at optimizing the conditions for the laboratory production of large quantities of AFs and FBs for use in the animal experiments. A. flavus and F. verticillioides strains, previously isolated from maize in Kenya, were used. Levels of AFB1 and total FBs (FB1, FB2, and FB3) in different growth substrates were screened using ELISA methods. Maize kernels inoculated with three different strains of A. flavus simultaneously and incubated at 29 °C for 21 days had the highest AFB1 level of 12,550 ± 3397 μg/kg of substrate. The highest level of total FBs (386,533 ± 153,302 μg/kg of substrate) was detected in cracked maize inoculated with three different strains of F. verticillioides and incubated for 21 days at temperatures of 22–25 °C in a growth chamber fitted with yellow light. These two methods are recommended for the mass production of AFB1 and FBs for animal feeding trials. Full article
Show Figures

Figure 1

20 pages, 3523 KiB  
Article
Screening of Lactiplantibacillus plantarum Strains from Sourdoughs for Biosuppression of Pseudomonas syringae pv. syringae and Botrytis cinerea in Table Grapes
by Mariana Petkova, Velitchka Gotcheva, Milena Dimova, Elena Bartkiene, João Miguel Rocha and Angel Angelov
Microorganisms 2022, 10(11), 2094; https://doi.org/10.3390/microorganisms10112094 - 22 Oct 2022
Cited by 11 | Viewed by 2384
Abstract
Grapes (Vitis vinifera L.) are an essential crop for fresh consumption and wine production. Vineyards are attacked by several economically important bacterial and fungal diseases that require regular pesticide treatment. Among them, Pseudomonas syringae pv. syringae (Ps. syringae) and Botrytis [...] Read more.
Grapes (Vitis vinifera L.) are an essential crop for fresh consumption and wine production. Vineyards are attacked by several economically important bacterial and fungal diseases that require regular pesticide treatment. Among them, Pseudomonas syringae pv. syringae (Ps. syringae) and Botrytis cinerea (B. cinerea) infections cause huge economic losses. The fresh fruit market has shifted to functional natural foodstuffs with clear health benefits and a reduced use of chemicals along the production chain. Lactic acid bacteria (LAB) have a biopreservative effect and are applied to ensure food safety in response to consumers’ demands. In the present study, the possibilities of using microorganisms with a potential antimicrobial effect against Ps. syringae and B. cinerea in the production of table grapes were investigated. LAB of the genus Lactiplantibacillus can be a natural antagonist of pathogenic bacteria and fungi by releasing lactic acid, acetic acid, ethanol, carbon dioxide and bacteriocins in the medium. The present study focuses on the characterization of nine Lactiplantibacillus plantarum (Lp. plantarum) strains isolated from spontaneously fermented sourdoughs. Species-specific PCR identified the isolated LAB for partial recA gene amplification with an amplicon size of 318 bp. RAPD-PCR analysis showed the intraspecific diversity of the individual strains. Thirteen plantaricin-like peptides (PlnA, PlnB, PlnC, PlnD, PlnEF, PlnG, PlnI, PlnJ, PlnK, PlnN, PlnNC8, PlnS, and PlnW) produced by isolated Lp. plantarum strains were detected by PCR with gene-specific primers. The key features for future industrial applications were their antimicrobial properties. The culture medium and cell-free supernatant (CFS) were used to establish in vitro antimicrobial activities of Lp. plantarum strains against Ps. syringae and B. cinerea, and inhibition of phytopathogen development was observed. The inhibitory effect of the CFS (cell-free supernatant) of all strains was assessed by infecting table grapes with these pathogens in in vivo experiments. Lp. plantarum Q4 showed the most effective suppression of the pathogens both in vitro and in vivo, which indicates its potential use as a biocontrol agent against berry rot and grey rot on grapes, caused by Ps. syringae and B. cinerea. Full article
Show Figures

Figure 1

14 pages, 3084 KiB  
Article
Inactivation of Bacillus subtilis by Curcumin-Mediated Photodynamic Technology through Inducing Oxidative Stress Response
by Li Dong, Jianran Qin, Luyang Tai, Kangyi Mou, Xiaojun Liao, Fang Chen and Xiaosong Hu
Microorganisms 2022, 10(4), 802; https://doi.org/10.3390/microorganisms10040802 - 12 Apr 2022
Cited by 10 | Viewed by 2557
Abstract
Photodynamic sterilization technology (PDT) is widely used in disease therapy, but its application in the food industry is still at the research stage because of the limitations of food-grade photosensitizers. Curcumin exhibits photosensitivity and is widely used as a food additive for its [...] Read more.
Photodynamic sterilization technology (PDT) is widely used in disease therapy, but its application in the food industry is still at the research stage because of the limitations of food-grade photosensitizers. Curcumin exhibits photosensitivity and is widely used as a food additive for its natural color. This study aimed to determine the effect of curcumin-mediated photodynamic technology (Cur-PDT) on Bacillus subtilis and to elucidate the anti-bacterial mechanism involved. First, the effects of curcumin concentration, duration of light irradiation, light intensity, and incubation time on the inactivation of B. subtilis were analyzed. It was found that Cur-PDT inactivated 100% planktonic cells with 50 μmol/L curcumin in 15 min (120 W). Then, the cell morphology, oxidation state and the expression of membrane structure- and DNA damage-related genes of B. subtilis vegetative cells were investigated under different treatment conditions. The membrane permeability of cells was enhanced and the cell membrane structure was damaged upon treatment with Cur-PDT, which were exacerbated with increases of treatment time and curcumin concentration. Meanwhile, the production of reactive oxygen species increased and the activities of the antioxidant enzymes SOD, GPX, and CAT decreased inside the cells. Furthermore, the Cur-PDT treatment significantly downregulated the mRNA of the membrane protein TasA and upregulated the DNA damage recognition protein UvrA and repair protein RecA of B. subtilis. These results suggested that curcumin-mediated PDT could effectively inactivate B. subtilis by inducing cell redox state imbalance, damaging DNA, and disrupting membrane structures. Full article
Show Figures

Figure 1

Review

Jump to: Editorial, Research

18 pages, 1228 KiB  
Review
The Impacts of Lactiplantibacillus plantarum on the Functional Properties of Fermented Foods: A Review of Current Knowledge
by Birsen Yilmaz, Sneh Punia Bangar, Noemi Echegaray, Shweta Suri, Igor Tomasevic, Jose Manuel Lorenzo, Ebru Melekoglu, João Miguel Rocha and Fatih Ozogul
Microorganisms 2022, 10(4), 826; https://doi.org/10.3390/microorganisms10040826 - 15 Apr 2022
Cited by 66 | Viewed by 8203
Abstract
One of the most varied species of lactic acid bacteria is Lactiplantibacillus plantarum (Lb. plantarum), formerly known as Lactobacillus plantarum. It is one of the most common species of bacteria found in foods, probiotics, dairy products, and beverages. Studies related [...] Read more.
One of the most varied species of lactic acid bacteria is Lactiplantibacillus plantarum (Lb. plantarum), formerly known as Lactobacillus plantarum. It is one of the most common species of bacteria found in foods, probiotics, dairy products, and beverages. Studies related to genomic mapping and gene locations of Lb. plantarum have shown the novel findings of its new strains along with their non-pathogenic or non-antibiotic resistance genes. Safe strains obtained with new technologies are a pioneer in the development of new probiotics and starter cultures for the food industry. However, the safety of Lb. plantarum strains and their bacteriocins should also be confirmed with in vivo studies before being employed as food additives. Many of the Lb. plantarum strains and their bacteriocins are generally safe in terms of antibiotic resistance genes. Thus, they provide a great opportunity for improving the nutritional composition, shelf life, antioxidant activity, flavour properties and antimicrobial activities in the food industry. Moreover, since some Lb. plantarum strains have the ability to reduce undesirable compounds such as aflatoxins, they have potential use in maintaining food safety and preventing food spoilage. This review emphasizes the impacts of Lb. plantarum strains on fermented foods, along with novel approaches to their genomic mapping and safety aspects. Full article
Show Figures

Figure 1

24 pages, 1049 KiB  
Review
Antimicrobial Impacts of Microbial Metabolites on the Preservation of Fish and Fishery Products: A Review with Current Knowledge
by Nikheel Bhojraj Rathod, Nilesh Prakash Nirmal, Asif Pagarkar, Fatih Özogul and João Miguel Rocha
Microorganisms 2022, 10(4), 773; https://doi.org/10.3390/microorganisms10040773 - 3 Apr 2022
Cited by 26 | Viewed by 8096
Abstract
Microbial metabolites have proven effects to inhibit food spoilage microbiota, without any development of antimicrobial resistance. This review provides a recent literature update on the preservative action of metabolites derived from microorganisms on seafood. Fish and fishery products are regarded as a myriad [...] Read more.
Microbial metabolites have proven effects to inhibit food spoilage microbiota, without any development of antimicrobial resistance. This review provides a recent literature update on the preservative action of metabolites derived from microorganisms on seafood. Fish and fishery products are regarded as a myriad of nutrition, while being highly prone to spoilage. Several proven controversies (antimicrobial resistance and health issues) related to the use of synthetic preservatives have caused an imminent problem. The demand for minimally processed and naturally preserved clean-label fish and fishery products is on rise. Metabolites derived from microorganisms have exhibited diverse preservation capacities on fish and fishery products’ spoilage. Inclusions with other preservation techniques, such as hurdle technology, for the shelf-life extension of fish and fishery products are also summarized. Full article
Show Figures

Figure 1

Back to TopTop