Effects of Enterococcus faecalis UGRA10 and the enterocin AS-48 against the fish pathogen Lactococcus garvieae. Studies in vitro and in vivo.
Martínez-Bueno M, Valdivia E Abstract The aim of this study was to evaluate the effects of Enterococcus faecalis UGRA10 and its enterocin AS-48 against the fish pathogen Lactococcus garvieae. The minimum bactericidal concentrations of AS-48 against L. garvieae CECT 5807, 5806, and 5274 were 15.62, 15.62, and 7.81 μg/ml respectively. In broth cultures, enterocin at 100, 50, and 25 μg/ml reduced 108 CFU/ml lactococci after 2, 5, and 10 h, respectively. In co-cultures of UGRA10/L. garvieae at a 1/10 CFU/ml ratio, lactococci were eliminated after 24 h. Studies on UGRA10 biosafety and AS-48 tox...
Source: Food Microbiology - October 10, 2018 Category: Food Science Authors: Baños A, Ariza JJ, Nuñez C, Gil-Martínez L, García-López JD, Martínez-Bueno M, Valdivia E Tags: Food Microbiol Source Type: research

Survival of Listeria monocytogenes during in vitro gastrointestinal digestion after exposure to 5 and 0.5 % sodium chloride.
In this study, a recently developed internationally harmonized static in vitro digestion (IVD) model was used to investigate the survival of L. monocytogenes in the gastric and intestinal phases after exposure to 5 or 0.5% NaCl. Six isolates from three Scandinavian foodborne listeriosis outbreaks, all related to NaCl containing foods, the EGDe reference strain and an EGDe mutant, deleted for the major stress regulator gene, sigB, were included. A ten-fold reduction of NaCl in the cultivation media significantly reduced the survival fraction of the EGDe strain in the IVD model while one of the clinical outbreak isolates sho...
Source: Food Microbiology - October 10, 2018 Category: Food Science Authors: Pettersen KS, Skjerdal T, Wasteson Y, Lindbäck T, Vegarud G, Comi I, Aspholm M Tags: Food Microbiol Source Type: research

Development and application of a real-time polymerase chain reaction method for quantification of Escherichia coli in oysters (Crassostrea gigas).
The objective of this study was to develop a qPCR method for quantification of E. coli in oysters. Additionally, different methods were evaluated for DNA extraction from oyster samples and the more reliable method was chosen. Primers and probe were designed targeting uidA gene of E. coli and shown to specifically amplify DNA from E. coli. Standard curves with bacterial DNA extracted from oysters samples artificially inoculated with E. coli were conducted. A good correlation was noticed when the qPCR method was compared to a culture method in oyster samples. This is the first report of a method exclusively developed for dir...
Source: Food Microbiology - October 10, 2018 Category: Food Science Authors: Miotto M, Fonseca AA, Barretta C, da Silva HS, Pellizzaro T, De Dea Lindner J, Vieira CRW, Parveen S, Prudencio ES Tags: Food Microbiol Source Type: research

Synthesis of prebiotic galactooligosaccharides from lactose and lactulose by dairy propionibacteria.
ate G Abstract The potential of probiotic bacteria to produce prebiotic oligosaccharides by transgalactosylation has been minimally studied. In this work, we screened the β-galactosidase (β-gal) activity of dairy propionibacteria (PAB) isolated from Argentinean foods to select strains for the synthesis of oligosaccharides from lactose (GOS) and lactulose (OsLu). PAB, when grown in a medium with lactose as a carbon source, were disrupted, and the cell-free extracts were assayed for β-gal activity. Nine strains grew on lactose and showed β-gal activities from 0.27 to 2.60 U mL-1. Propionibacteriu...
Source: Food Microbiology - October 10, 2018 Category: Food Science Authors: Sabater C, Fara A, Palacios J, Corzo N, Requena T, Montilla A, Zárate G Tags: Food Microbiol Source Type: research

Genomic and metatranscriptomic analyses of Weissella koreensis reveal its metabolic and fermentative features during kimchi fermentation.
Abstract The genomic and metabolic features of Weissella koreensis, one of the major lactic acid bacteria in kimchi, were investigated through genomic, metabolic, and transcriptomic analyses for the genomes of strains KCTC 3621T, KACC 15510, and WiKim0080. W. koreensis strains were intrinsically vancomycin-resistant and harbored potential hemolysin genes that were actively transcribed although no hemolysin activity was detected. KEGG and reconstructed fermentative metabolic pathways displayed that W. koreensis strains commonly employ the heterolactic pathway to produce d-lactate, ethanol, acetate, CO2, d...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Jeong SE, Chun BH, Kim KH, Park D, Roh SW, Lee SH, Jeon CO Tags: Food Microbiol Source Type: research

Control of microbes on barley grains using peroxyacetic acid and electrolysed water as antimicrobial agents.
Abstract The extent and type of microbial growth on barley grain is a key determinant of malt quality for beer production, as problematic microbial products can persist into the brewing process and impact beer quality. Microbial composition on malting barley grain are influenced by field growth, storage and malting conditions. The present study investigated the efficacy of electrolysed water (EW) with free chlorine concentrations of 5, 50, 100 and 500 ppm, as well as peroxyacetic acid (PAA) at 100 and 500 ppm, as pre-steep treatments to control microbes on grains during the malting process. The research determ...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Rood L, Koutoulis A, Bowman JP, Evans DE, Stanley RA, Kaur M Tags: Food Microbiol Source Type: research

Characterization of bacteria and yeasts isolated from traditional fermentation starter (Fen-Daqu) through a 1H NMR-based metabolomics approach.
This study highlights the specific functions of S. cerevisiae, S. fibuligera, B. licheniformis, W. anomalus and lactic acid bacteria in the production of light-flavour baijiu (fen-jiu). Our results show that all investigated species deliver an important contribution to the functionality of the fermentation starter Daqu. PMID: 30166130 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Li RY, Zheng XW, Zhang X, Yan Z, Wang XY, Han BZ Tags: Food Microbiol Source Type: research

Microbial community dynamics of Dan'er barley grain during the industrial malting process.
Abstract The microbes associated with barley grains are known to have either deleterious or beneficial effects on the malting process, thereby affecting the quality of malt and even beer. Dan'er barley is the major cultivar grown in Jiangsu Province in China, malt derived from this cultivar, however, invariably causes filtration problems. To understand the microbial community of Dan'er barley and its probable effects on malt quality and subsequent brewing process, the present study combined culture-dependent methods and culture-independent PCR denaturing gradient gel electrophoresis (PCR-DGGE) strategies. The resu...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Li X, Cai G, Wu D, Zhang M, Lin C, Lu J Tags: Food Microbiol Source Type: research

Aerobic and respirative growth of heterofermentative lactic acid bacteria: A screening study.
Abstract Heterofermentative lactic acid bacteria (76 strains) belonging to Lactobacillus, Leuconostoc and Weissella species which are important in fermentation, spoilage or as probiotics were screened in a factorial experiment for their ability to grow, produce catalase and consume oxygen in aerobiosis or in anaerobiosis, with or without supplementation with hemin and/or menaquinone in a medium containing glucose as a carbohydrate source. Aerobiosis improved growth with a few exceptions. The effect of supplementation with heme and/or menaquinone was strain specific and clear evidence of heme-boosted respiration wa...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Zotta T, Ricciardi A, Ianniello RG, Storti LV, Glibota NA, Parente E Tags: Food Microbiol Source Type: research

Polyhexamethylene guanidine as a fungicide, disinfectant and wound protector in lemons challenged with Penicillium digitatum.
Abstract Citrus green mold, a postharvest disease caused by Penicillium digitatum, provokes important economic losses on lemon production. Here, the effectiveness of polyhexamethylene guanidine (PHMG) to inhibit P. digitatum growth and to control green mold on artificially infected lemons was evaluated. At sublethal concentrations, PHMG inhibited conidia germination and infectivity (5 mg L-1), and mycelial growth (50 mg L-1). Viability of conidia was completely suppressed by treatment with 500 mg L-1 PHMG. In this condition, membrane integrity loss, cell wall disruption and ultrastructural alterat...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Olmedo GM, Cerioni L, Sepulveda M, Ramallo J, Rapisarda VA, Volentini SI Tags: Food Microbiol Source Type: research

Kluyveromyces marxianus yeast enables the production of low FODMAP whole wheat breads.
This study demonstrates the potential of inulinase-producing K. marxianus strains for the production of (whole meal) breads low in FODMAPs. PMID: 30166134 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Struyf N, Vandewiele H, Herrera-Malaver B, Verspreet J, Verstrepen KJ, Courtin CM Tags: Food Microbiol Source Type: research

Combined effect of a positively charged cinnamon leaf oil emulsion and organic acid on the inactivation of Listeria monocytogenes inoculated on fresh-cut Treviso leaves.
This study was performed to examine the inhibitory effect of combined treatments with a positively charged cinnamon leaf oil (P-CL) emulsion and various organic acids against Listeria monocytogenes inoculated on fresh-cut Treviso leaves. Combined treatments with a P-CL emulsion and an organic acid exhibited a higher inhibitory effect than treatment with each alone or NaOCl. The highest inhibitory effect was achieved by combined treatment with the P-CL emulsion and lactic acid (LA), which showed a 2.85-log reduction compared to distilled water washing. In addition, the inhibitory effect of the combined treatment was maintai...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Kang JH, Song KB Tags: Food Microbiol Source Type: research

Modelling the growth kinetics of Listeria monocytogenes in pasta salads at different storage temperatures and packaging conditions.
Abstract The aim of this study was to model Listeria monocytogenes growth kinetics in ready to eat full meal pasta salads, containing fresh and cooked ingredients. With this aim, laboratory prepared salads, representing two formulations of commercial pasta salads, were spiked with L. monocytogenes and tested under categorised packaging and storage temperature conditions. L. monocytogenes enumeration results collected in 15 different laboratory prepared salad datasets were analysed with primary and secondary models. The models showing the best fit to describe L. monocytogenes growth kinetics in the l...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: De Cesare A, Vitali S, Tessema GT, Trevisani M, Fagereng TM, Beaufort A, Manfreda G, Skjerdal T Tags: Food Microbiol Source Type: research

Performance of Leuconostoc citreum FDR241 during wheat flour sourdough type I propagation and transcriptional analysis of exopolysaccharides biosynthesis genes.
This study focused on the performance of the dextran producer Leuconostoc citreum as starter culture during 30 days of wheat flour type I sourdough propagation (back-slopping). As confirmed by RAPD-PCR analysis, the strain dominated throughout the propagation procedure, consisting of daily fermentations at 20 °C. The sourdoughs were characterized by consistent lactic acid bacteria cell density and acidification parameters, reaching pH values of 4.0 and mild titratable acidity. Carbohydrates consumption remained consistent during the propagation procedure, leading to formation of mannitol and almost equimolar amount o...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Coda R, Xu Y, Moreno DS, Mojzita D, Nionelli L, Rizzello CG, Katina K Tags: Food Microbiol Source Type: research

Effectiveness of polymeric coated films containing bacteriocin-producer living bacteria for Listeria monocytogenes control under simulated cold chain break.
i R Abstract Nisin, enterocin 416K1 and living bacteriocin-producer Enterococcus casseliflavus IM 416K1 have been entrapped in polyvinyl alcohol (PVOH) based coatings applied to poly (ethylene terephthalate) (PET) films, and their effectiveness in the control of the growth of Listeria monocytogenes ATCC 19117 has been tested. The anti-listerial activity of the doped coated films was evaluated by both a modified agar diffusion assay and a direct contact with artificially contaminated precooked chicken fillets stored at 4 °C, 22 °C and under simulated cold chain break conditions (1 day at 30 °C...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Degli Esposti M, Toselli M, Sabia C, Messi P, de Niederhäusern S, Bondi M, Iseppi R Tags: Food Microbiol Source Type: research

Effect of temperature and pH on the community dynamics of coagulase-negative staphylococci during spontaneous meat fermentation in a model system.
Abstract Coagulase-negative staphylococci (CNS) contribute to the product quality of fermented meats. In spontaneously fermented meats, CNS communities are variable and difficult to predict, as their compositions depend on a superposed combination of different processing factors. To partially disentangle this superposition, a meat model system was used to study the influence of temperature and pH on the CNS community dynamics. Therefore, cured pork mince was prepared that was divided into three batches of different initial acidity levels, namely pH 5.7, pH 5.5, and pH 5.3. These three batches were incubated at thr...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Stavropoulou DA, Filippou P, De Smet S, De Vuyst L, Leroy F Tags: Food Microbiol Source Type: research

Use of biochemical miniaturized galleries, rRNA based lateral flow assay and Real Time PCR for Cronobacter spp. confirmation.
Abstract Identification of Cronobacter represent a major challenge for laboratories testing powdered infant formula (PIF). In the present study, two biochemical galleries and three molecular methods have been applied to confirm 276 Cronobacter spp. and non-Cronobacter isolates from different sources. Using the latest database of API 20 E and ID 32 E biochemical miniaturized kits, 53% and 78% of the isolates were identified respectively. From the available results, total accuracy for Cronobacter detection was in 97% (API 20 E) and 99% (ID 32 E). The three molecular methods were based on rRNA based lateral f...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Tomas D, Fan M, Zhu S, Klijn A Tags: Food Microbiol Source Type: research

High prevalence of Bacillus subtilis-infecting bacteriophages in soybean-based fermented foods and its detrimental effects on the process and quality of Cheonggukjang.
In conclusion, B. subtilis phages are widespread in Korean soybean-based fermented foods and it should be of great concern as phages may hamper the bacterial growth during fermentation and yield poor quality products. PMID: 30166141 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Ghosh K, Kang HS, Hyun WB, Kim KP Tags: Food Microbiol Source Type: research

Fog, phenolic acids and UV-A light irradiation: A new antimicrobial treatment for decontamination of fresh produce.
This study evaluates synergistic interactions of food grade phenolic acids (gallic and ferulic acid) and UV-A light to achieve decontamination of fresh produce using a fog to improve dispersion of the phenolic acids on produce surface. Nonvirulent strains of Escherichia coli O157:H7 and Listeria innocua were used as model bacteria and spinach was selected as a model fresh produce. Synergistic combination of a fog deposited phenolic acid and a UV-A light treatment achieved reduction in bacterial plate count up to 2 log CFU/cm2 independently of the initial load of the bacteria (104 or 106 CFU/cm2). Following the treatment,...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Cossu A, Huang K, Cossu M, Tikekar RV, Nitin N Tags: Food Microbiol Source Type: research

Evaluation of the efficacy of multiple physical, biological and natural antimicrobial interventions for control of pathogenic Escherichia coli on beef.
Abstract Antimicrobial effects of multiple physical, biological and natural interventions on pathogenic Escherichia coli in raw beef were assessed. A cocktail of E. coli strains was inoculated onto gamma-irradiated beef and enumerated immediately after each intervention and during storage at 4 °C for 7 days. Of the physical interventions, silver-containing antimicrobial packaging and ozone gas treatment did not show significant antimicrobial effects, however cold plasma treatment reduced E. coli levels by 0.9 and 1.82 log10 CFU/cm2 after 2 and 5 min treatments, respectively. A phage cocktail reduced E. c...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Stratakos AC, Grant IR Tags: Food Microbiol Source Type: research

Survival of Listeria innocua on Fuji apples under commercial cold storage with or without low dose continuous ozone gaseous.
This study evaluated the fate of Listeria innocua, a non-pathogenic species closely related to Listeria monocytogenes, on Fuji apple fruit surfaces during commercial cold storage with and without continuous low doses of gaseous ozone. Unwaxed Fuji apples of commercially acceptable maturity were inoculated with 6.0-7.0 Log10 CFU L. innocua/apple, and subjected to refrigerated air (RA, 33 °F), controlled atmosphere (CA, 33 °F, 2% O2, 1% CO2), or CA with low doses of ozone gas (50.0 -87.0 ppb ) storage in a commercial facility for 30 weeks. A set of uninoculated apples was simultaneously subjected to ...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Sheng L, Hanrahan I, Sun X, Taylor MH, Mendoza M, Zhu MJ Tags: Food Microbiol Source Type: research

Inactivation of Listeria monocytogenes and Salmonella spp. on cantaloupe rinds by blue light emitting diodes (LEDs).
This study evaluated the potential of blue light-emitting diodes (LED) of wavelength 405 and 460 nm in combination with sodium chlorophyllin to inactivate Listeria monocytogenes and Salmonella spp. on cantaloupe rind. A cocktail culture of L. monocytogenes or Salmonella spp. strains was surface inoculated onto cantaloupe rinds to reach a final concentration of 4 log CFU/cm2 and dip-treated in a 100 μM sodium copper chlorophyllin solution. The cantaloupe samples were then exposed to 405 or 460 nm LEDs at a total dose of 1210 J/cm2 and 5356 J/cm2, respectively, at 4 and 20 °C. Results showed that the antib...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Josewin SW, Kim MJ, Yuk HG Tags: Food Microbiol Source Type: research

Evaluation of biocontrol capacity of Pseudomonas graminis CPA-7 against foodborne pathogens on fresh-cut pear and its effect on fruit volatile compounds.
aire L, Abadias M Abstract The application of microorganisms to control the growth of foodborne pathogens is an alternative to the use of chemical additives. In this work, Pseudomonas graminis CPA-7 was tested as a biocontrol agent against Salmonella enterica and Listeria monocytogenes on fresh-cut pear under conditions that simulate its commercial application at 5 ± 1 °C (under a modified atmosphere and antioxidant solution). The quality of the fresh-cut fruit, including the ethanol and acetaldehyde contents and the volatile profile, was determined. After the storage period, the L. monocytog...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Iglesias MB, López ML, Echeverría G, Viñas I, Zudaire L, Abadias M Tags: Food Microbiol Source Type: research

Thermal inactivation of Aspergillus flavus in peanut kernels as influenced by temperature, water activity and heating rate.
In this study, thermal inactivation kinetics of Aspergillus flavus in peanut kernel flour at four water activity (aw) levels (0.720, 0.783, 0.846, and 0.921) with three temperatures for each aw was studied using a thermal-death-time heating block system and fitted with first-order kinetic and Weibull models. The influence of heating rates on thermotolerance of Aspergillus flavus was also investigated. The results showed that the Weibull distribution model had better coefficient of determination from 0.954 to 0.996, as compared to that (from 0.866 to 0.980) of the first-order kinetic model. An upward concavity was found wit...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Zhang S, Zhang L, Lan R, Zhou X, Kou X, Wang S Tags: Food Microbiol Source Type: research

Adherence factors of enterohemorrhagic Escherichia coli O157:H7 strain Sakai influence its uptake into the roots of Valerianella locusta grown in soil.
This study identified intrinsic bacterial factors that play a crucial role during the internalization of EHEC O157:H7 strain Sakai into the roots of Valerianella locusta grown under the growth conditions in a greenhouse. PMID: 30166148 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Eißenberger K, Moench D, Drissner D, Weiss A, Schmidt H Tags: Food Microbiol Source Type: research

Monitoring bacterial communities in ε-Polylysine-treated bighead carp (Aristichthys nobilis) fillets using culture-dependent and culture-independent techniques.
In conclusion, ε-Polylysine altered the bacterial communities and delayed quality deterioration of bighead carp fillets during chilled storage. PMID: 30166149 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Liu X, Li D, Li K, Luo Y Tags: Food Microbiol Source Type: research

Occurrence of lactic acid bacteria and yeasts at species and strain level during spontaneous fermentation of maw è, a cereal dough produced in West Africa.
Occurrence of lactic acid bacteria and yeasts at species and strain level during spontaneous fermentation of mawè, a cereal dough produced in West Africa. Food Microbiol. 2018 Dec;76:267-278 Authors: Houngbédji M, Johansen P, Padonou SW, Akissoé N, Arneborg N, Nielsen DS, Hounhouigan DJ, Jespersen L Abstract Mawè is a West African spontaneous fermented cereal-based dough. Different types of mawè exist varying in type of cereal and/or production condition, with fermentations lasting 24-48 h. With the aim of obtaining a comprehensive understanding of the microbial ec...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Houngbédji M, Johansen P, Padonou SW, Akissoé N, Arneborg N, Nielsen DS, Hounhouigan DJ, Jespersen L Tags: Food Microbiol Source Type: research

A bioinformatics pipeline integrating predictive metagenomics profiling for the analysis of 16S rDNA/rRNA sequencing data originated from foods.
Abstract The recent advances in molecular biology, such as the advent of next-generation sequencing (NGS) platforms, have paved the way to new exciting tools which rapidly transform food microbiology. Nowadays, NGS methods such as 16S rDNA/rRNA metagenomics or amplicon sequencing are used for the taxonomic profiling of the food microbial communities. Although 16S rDNA/rRNA NGS-based microbial data are not suited for the investigation of the functional potential of the identified operational taxonomic units as compared to shotgun metagenomics, advances in the bioinformatics discipline allow now the performance of s...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Mataragas M, Alessandria V, Ferrocino I, Rantsiou K, Cocolin L Tags: Food Microbiol Source Type: research

Modeling the effect of pH, water activity, and ethanol concentration on biofilm formation of Staphylococcus aureus.
Abstract In this work, the effect of environmental factors on Staphylococcus aureus (ATCC 13150) biofilm formation in tryptic soy broth was investigated under different ranges of pH (3.0-9.5), ethanol concentration (EtOH 0.0-20.0%), and aw (NaCl, 0.866-0.992). Biofilm formation was quantified using the crystal violet staining method and optical density (OD: 590 nm) measurements. Biofilm formation was significantly stronger at pH and aw close to S. aureus optimal growth conditions, while it was high at EtOH around 2.5-3.5%. Data sets from the difference between the OD measurements of the test and control (Δ...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Tango CN, Akkermans S, Hussain MS, Khan I, Van Impe J, Jin YG, Oh DH Tags: Food Microbiol Source Type: research

Impact of the timing and the nature of nitrogen additions on the production kinetics of fermentative aromas by Saccharomyces cerevisiae during winemaking fermentation in synthetic media.
Abstract During alcoholic fermentation, many parameters, including the nitrogen composition of the must, can affect aroma production. The aim of this study was to examine the impact of several types of nitrogen sources added at different times during fermentation. Nitrogen was added as ammonium or a mixture of amino acids at the beginning of fermentation or at the start of the stationary phase. These conditions were tested with two Saccharomyces cerevisiae strains that have different nitrogen requirements. The additions systematically reduced the fermentation duration. The aroma production was impacted by both the...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Seguinot P, Rollero S, Sanchez I, Sablayrolles JM, Ortiz-Julien A, Camarasa C, Mouret JR Tags: Food Microbiol Source Type: research

Edible processed insects from e-commerce: Food safety with a focus on the Bacillus cereus group.
In this study, mealworms, crickets, mole crickets and silkworms that are widely available online were investigated for microbial quality traits. Whereas water activity and pH results revealed a stable product, microbiota characterisation highlighted wide variability among the analysed insect species. Among the microbial targets considered in this study, total viable count, total aerobic spores and Bacillus cereus count were the most suitable for describing the food safety and microbial quality of these products. Endospore-forming bacteria ascribed to the B. cereus group were identified with genetic methods and putative vir...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Fasolato L, Cardazzo B, Carraro L, Fontana F, Novelli E, Balzan S Tags: Food Microbiol Source Type: research

Microencapsulation of a Staphylococcus phage for concentration and long-term storage.
Abstract In an effort to reduce food safety risks, virulent phages are investigated as antibacterial agents for the control of foodborne pathogens. The aim of this study was to evaluate microencapsulation (ME) as a tool to concentrate and store staphylococcal bacteriophages. As a proof of concept, phage Team1 belonging to the Myoviridae family was microencapsulated in alginate gel particles of 0.5 mm (micro-beads) and 2 mm (macro-beads) of diameter. Gel contraction occurred during the hardening period in the CaCl2 solution, and the diameters of the initial alginate droplets shrunk by 16% (micro-beads) and 44% ...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: El Haddad L, Lemay MJ, Khalil GE, Moineau S, Champagne CP Tags: Food Microbiol Source Type: research

Comparative proteomic analysis of foodborne Salmonella Enteritidis SE86 subjected to cold plasma treatment.
In this study, the proteomic profile of Salmonella Enteritidis SE86 subjected to cold plasma treatment was investigated. The number of viable S. Enteritidis SE86 cells was analyzed at different time intervals upon exposure to cold plasma and approximately 100 μg of S. Enteritidis SE86 protein extracts were analyzed by Multidimensional Protein Identification Technology (MudPIT). The results demonstrated that no significant changes in cell counts were detected for up to 20 min exposure to cold plasma, and 2 log reduction was achieved after 60 min. Overall, 1096 proteins were identified, with 249 detected only in p...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Ritter AC, Santi L, Vannini L, Beys-da-Silva WO, Gozzi G, Yates J, Ragni L, Brandelli A Tags: Food Microbiol Source Type: research

Viral community predicts the geographical origin of fermented vegetable foods more precisely than bacterial community.
In this study, the viral and host bacterial communities from 10 representative samples of Korean and Chinese kimchi were analyzed in triplicate using next-generation sequencing technology. The overall structures of bacterial and viral communities were dominated by lactic acid bacteria in phylum Firmicutes and bacteriophages in order Caudovirales, respectively. For the single-stranded DNA (ssDNA) viruses, bacteriophage in family Microviridae were dominant in Korean kimchi. After correction for multiple comparisons using false discovery rate (FDR, P 
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Jung MJ, Kim MS, Yun JH, Lee JY, Kim PS, Lee HW, Ha JH, Roh SW, Bae JW Tags: Food Microbiol Source Type: research

Influence of lactate and acetate removal on the microbiota of French fresh pork sausages.
Abstract The microbiota of fresh French pork sausages were characterised in five batches of comminuted pork meat that were equally divided into two formulations either containing the acid-based preservatives lactate and acetate, or no preservatives. Conventional microbiological analysis and high-throughput 16S rDNA amplicon sequencing methods were performed on meat batches packed under modified atmosphere (70% oxygen and 30% carbon dioxide) during chilled storage. In addition, meat pH and colour, and gas composition of the packages were monitored until the end of the shelf-life. During storage, the population of m...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Bouju-Albert A, Pilet MF, Guillou S Tags: Food Microbiol Source Type: research

Predicting human norovirus infectivity - Recent advances and continued challenges.
Abstract Human norovirus is the leading cause of foodborne illness globally, imposing a considerable public health and economic burden. Historically, one of the major obstacles to the study of human noroviruses has been the lack of an in vitro cultivation system. In addition to hindering elucidation of viral pathogenesis, research efforts have been limited by the inability to discriminate infectious from non-infectious viral particles. Two recent breakthrough human norovirus in vitro cultivation system systems have been reported, but in their current state, may be unsuitable for routine detection or study of human...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Manuel CS, Moore MD, Jaykus LA Tags: Food Microbiol Source Type: research

Monomeric catechin and dimeric procyanidin B2 against human norovirus surrogates and their physicochemical interactions.
The objectives of this study were to compare the antiviral activity between monomeric catechin and dimeric procyanidin B2 (PB2) using cultivable human norovirus surrogates (feline calicivirus (FCV-F9) and murine norovirus (MNV-1)) and to understand their potential antiviral mechanism using virus-like particles (VLPs) and the P domain of human norovirus GII (HNoV GII.4). Surrogate viruses at 5 log PFU/mL were treated with 0.5-5 mg/mL monomeric catechin monohydrate, PB2 or phosphate buffered saline (PBS, pH 7.2; control) at 37 °C over 24 h. Infectivity was determined using plaque assays and data from triplicate exp...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Liu D, Deng J, Joshi S, Liu P, Zhang C, Yu Y, Zhang R, Fan D, Yang H, D'Souza DH Tags: Food Microbiol Source Type: research

Mrakia gelida in brewing process: An innovative production of low alcohol beer using a psychrophilic yeast strain.
In this study the ethanol content and the volatile profile of a beer obtained using the basidiomycetous psychrophilic yeast strain Mrakia gelida DBVPG 5952 was compared with that produced by a commercial starter for low alcohol beers, Saccharomycodes ludwigii WSL17. The two beers were characterized by a low alcohol content (1.40% and 1.32% v/v) and by a low diacetyl production (5.04 and 5.20 μg/L). However, the organoleptic characteristics of the beer obtained using M. gelida are more appreciated by the panelists, in comparison to the analogous produced with the commercial strain of S. ludwigii. PMID: 30166161 [P...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: De Francesco G, Sannino C, Sileoni V, Marconi O, Filippucci S, Tasselli G, Turchetti B Tags: Food Microbiol Source Type: research

Volatile organic compounds from Hypoxylon anthochroum endophytic strains as postharvest mycofumigation alternative for cherry tomatoes.
Medina-Romero YM Abstract The antifungal activity and chemical composition of the volatile organic compounds (VOCs) produced by four Hypoxylon anthochroum endophytic strains were analyzed. The bioactivity of the VOCs synthesized at different periods of incubation on rice medium was assessed, both in vivo and in vitro, against the phytopathogen Fusarium oxysporum. The in vivo effect was evaluated on cherry tomatoes, while the mechanism of action was determined in vitro analyzing the phytopathogen's growth, respiration and cell membrane permeability. In general, the VOCs from all strains and incubation periods sign...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Macías-Rubalcava ML, Sánchez-Fernández RE, Roque-Flores G, Lappe-Oliveras P, Medina-Romero YM Tags: Food Microbiol Source Type: research

Crab-meat-isolated psychrophilic spore forming bacteria inactivation by electron beam ionizing radiation.
S, Lyng JG, Álvarez I Abstract The present work was performed to evaluate the potential of electron beam ionizing radiation for the inactivation of three psychrophilic spore forming bacteria (Bacillus mycoides, Bacillus weihenstephanensis and Psychrobacillus psychrodurans) isolated from ready-to-eat brown crab (Cancer pagurus). Inactivation curves for the three spores were performed in both types of crab meat, brown and white. Also the effect of pH and water activity (aw) on the lethal efficacy of ionizing radiation, for the three different psychrophilic spore forming bacteria, was evaluated. The effects o...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Condón-Abanto S, Pedrós-Garrido S, Cebrián G, Raso J, Condón S, Lyng JG, Álvarez I Tags: Food Microbiol Source Type: research

Expression of genes involved in metabolism of phenolic compounds by Lactobacillus pentosus and its relevance for table-olive fermentations.
ba JL Abstract Genes with the potential to code for enzymes involved in phenolic compound metabolism were detected in the genome of Lactobacillus pentosus IG1, isolated from a green olive fermentation. Based on homology, these genes could code for a 6-P-β Glucosidase, two different Tannases, a Gallate decarboxylase and a p-Coumaric decarboxylase. Expression of up to seven of these genes was studied in L. pentosus IG1 (olive fermentation) and CECT4023T (corn silage), including responses upon exposure to relevant phenolic compounds and different olive extracts. Genes potentially coding Tannase, Gallate decarbox...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Carrasco JA, Lucena-Padrós H, Brenes M, Ruiz-Barba JL Tags: Food Microbiol Source Type: research

Analysis of frozen strawberries involved in a large norovirus gastroenteritis outbreak using next generation sequencing and digital PCR.
Johne R Abstract Virus-contaminated frozen berries have been frequently identified as cause of foodborne disease outbreaks. To provide new tools for virus detection and characterization in berries, next generation sequencing (NGS) and reverse transcription-digital PCR (RT-dPCR) techniques were tested here with strawberries previously involved in a large-scale norovirus (NoV) gastroenteritis outbreak in Germany. By NGS, about 29 million sequence reads were generated, which mainly showed identities to sequences from the plant matrix and from the bacterial flora. Most abundant virus sequences originated from plant-sp...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Bartsch C, Höper D, Mäde D, Johne R Tags: Food Microbiol Source Type: research

Several species of Penicillium isolated from chestnut flour processing are pathogenic on fresh chestnuts and produce mycotoxins.
Abstract A collection of 124 isolates of Penicillium spp. was created by monitoring fresh chestnuts, dried chestnuts, chestnut granulates, chestnut flour and indoor chestnut mills. Sequencing of the ITS region, β-tubulin and calmodulin, macro-morphology and secondary metabolite production made it possible to determine 20 species of Penicillium. P. bialowiezense was dominant in the fresh chestnuts, while P. crustosum was more frequent in the other sources. A pathogenicity test on chestnut showed that around 70% of the isolates were virulent. P. corylophilum and P. yezoense were not pathogenic, while the other ...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Prencipe S, Siciliano I, Gatti C, Garibaldi A, Gullino ML, Botta R, Spadaro D Tags: Food Microbiol Source Type: research

Quorum sensing asaI mutants affect spoilage phenotypes, motility, and biofilm formation in a marine fish isolate of Aeromonas salmonicida.
In this study the activity and role of AHLs in spoilage phenotypes, motility and biofilm formation of AE03 were investigated. The strain AE03 could induce Chromobacterium violaceum CV026 to produce the violacein pigment both at 28 °C and 4 °C in a density-dependent manner. Five types of AHLs were detected in AE03 culture by LC-MS/MS analysis, and N-butanoyl-l-homoserine lactone (C4-HSL) was a major signal molecule, reaching the highest concentration when incubated for 30 h at 28 °C. An asaI-mutant, constructed by a suicide plasmid, failed to produce short chain AHLs signal. Compared with wild type (WT...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Liu L, Yan Y, Feng L, Zhu J Tags: Food Microbiol Source Type: research

Revealing the influence of microbiota on the quality of Pu-erh tea during fermentation process by shotgun metagenomic and metabolomic analysis.
This study provides a perspective for bridging the gap between the microbiota and quality in Pu-erh tea, and benefited for further optimizing production efficiency and product quality. PMID: 30166168 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Li Z, Feng C, Luo X, Yao H, Zhang D, Zhang T Tags: Food Microbiol Source Type: research

The protective effect of food matrices on Listeria lytic bacteriophage P100 application towards high pressure processing.
In conclusion, at mild HHP treatment, phage P100 remained active in specific matrices and seems to present potential to be added in non-thermal inactivation of L. monocytogenes. PMID: 30166169 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Komora N, Bruschi C, Ferreira V, Maciel C, Brandão TRS, Fernandes R, Saraiva JA, Castro SM, Teixeira P Tags: Food Microbiol Source Type: research

Species composition, toxigenic potential and aggressiveness of Fusarium isolates causing Head Blight of barley in Uruguay.
TJ, Vero S Abstract Fusarium Head Blight (FHB) is a major constraint to barley production that substantially reduces yield and grain quality. FHB is also a major food safety concern because FHB pathogens contaminate grain with trichothecenes and other mycotoxins. DNA sequence-based analyses and in-vitro toxin assessments were used to characterize the species and trichothecene chemotype composition of FHB pathogens on barley in Uruguay. F. graminearum was the dominant species (89.7%), and three other members of the F. graminearum species complex (FGSC) were identified as FHB pathogens of barley in Uruguay for the ...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Garmendia G, Pattarino L, Negrín C, Martínez-Silveira A, Pereyra S, Ward TJ, Vero S Tags: Food Microbiol Source Type: research

Evaluation of a novel cocktail of six lytic bacteriophages against Shiga toxin-producing Escherichia coli in broth, milk and meat.
oni A Abstract Phages are potentially useful as antimicrobial agents in food, especially cocktails of different phages which may prevent the development of bacterial resistance. Biocontrol assays with a six-phage cocktail, which is lytic against DH5α, an enteropathogenic (EPEC) and two Shiga-toxigenic (STEC) Escherichia coli strains, were performed in Hershey-Mg broth, milk and meat at refrigerated (4 °C), room (24 °C) and abusive (37 °C) temperatures. At 4 °C, cell counts were significantly lower (2.2-2.8 log10 CFU/mL) when E. coli strains (∼109 CFU/mL) were challenged agains...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Tomat D, Casabonne C, Aquili V, Balagué C, Quiberoni A Tags: Food Microbiol Source Type: research

Modified atmosphere packaging decreased Pseudomonas fragi cell metabolism and extracellular proteolytic activities on meat.
This study showed that MAP is an effective food preservation strategy and revealed mechanisms by which MAP inhibits spoilage. PMID: 30166172 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Wang G, Ma F, Zeng L, Bai Y, Wang H, Xu X, Zhou G Tags: Food Microbiol Source Type: research

Modelling the growth of pear postharvest fungal isolates at different temperatures.
Abstract The effect of temperature on the mycelium growth kinetics of four postharvest fungal isolates (i.e., Penicillium expansum, Alternaria alternata, Botrytis cinerea and Rhizopus stolonifer) was assessed. A cardinal model with inflection (CMI) was used to describe the effect of the temperature on the growth rate (μ) and the lag time (λ) of each isolate. Cardinal temperature values such as Tmin, Tmax and Topt were estimated and isolates were sorted according to their growth rate and lag time duration. Additionally, model validation was performed on a medium prepared from mashed pear pulp and on artif...
Source: Food Microbiology - September 2, 2018 Category: Food Science Authors: Sardella D, Gatt R, Valdramidis VP Tags: Food Microbiol Source Type: research