The best of both worlds: a proposal for further integration of Candidatus names into the International Code of Nomenclature of Prokaryotes.

The naming of prokaryotes is governed by the International Code of Nomenclature of Prokaryotes (ICNP) and partially by the International Code of Nomenclature for Algae, Fungi and Plants (ICN). Such codes must be able to determine names of taxa in a universal and unambiguous manner, thus serving as a common language across different fields and activities. This unity is undermined when a new code of nomenclature emerges that overlaps in scope with an established, time-tested code and uses the same format of names but assigns different nomenclatural status values to the names. The resulting nomenclatural confusion is not beneficial to the wider scientific community. Such ambiguity is expected to result from the establishment of the 'Code of Nomenclature of Prokaryotes Described from DNA Sequence Data' ('SeqCode'), which is in general and specific conflict with the ICNP and the ICN. Shortcomings in the interpretation of the ICNP may have exacerbated the incompatibility between the codes. It is reiterated as to why proposals to accept sequences as nomenclatural types of species and subspecies with validly published names, now implemented in the SeqCode, have not been implemented by the International Committee on Systematics of Prokaryotes (ICSP), which oversees the ICNP. The absence of certain regulations from the ICNP for the naming of as yet uncultivated prokaryotes is an acceptable scientific argument, although it does not justify the establishment of a separate code. Moreover, the proposals rejected by the ICSP are unnecessary to adequately regulate the naming of uncultivated prokaryotes. To provide a better service to the wider scientific community, an alternative proposal to emend the ICNP is presented, which would result in Candidatus names being regulated analogously to validly published names. This proposal is fully consistent with previous ICSP decisions, preserves the essential unity of nomenclature and avoids the expected nomenclatural confusion.

Public Health Risk of Foodborne Pathogens in Edible African Land Snails, Cameroon.

In tropical countries, land snails are an important food source; however, foodborne disease risks are poorly quantified. We detected Campylobacter spp., Yersinia spp., Listeria spp., Salmonella spp., or Shiga-toxigenic Escherichia coli in 57%-86% of snails in Cameroon. Snail meat is a likely vector for enteric diseases in sub-Saharan Africa countries.

Epigenetic Changes in Saccharomyces cerevisiae Alters the Aromatic Profile in Alcoholic Fermentation.

Epigenetic changes in genomics provide phenotypic modification without DNA sequence alteration. This study shows that benzoic acid, a common food additive and known histone deacetylase inhibitor (HDACi), has an epigenetic effect on Saccharomyces cerevisiae. Benzoic acid stimulated formation of epigenetic histone marks H3K4Me2, H3K27Me2, H3K18ac, and H3Ser10p in S. cerevisiae and altered their phenotypic behavior, resulting in increased production of phenylethyl alcohol and ester compounds during alcoholic fermentation using wine as a representative model system. Our study demonstrates the HDACi activity of certain dietary compounds such as sodium butyrate, curcumin and anacardic acid, suggests the potential use of these dietary compounds in altering S. cerevisiae phenotypes without altering host-cell DNA. This study highlights the potential to use common dietary compounds to exploit epigenetic modifications for various fermentation and biotechnology applications as an alternative to genetic modification. These findings indicate that benzoic acid and other food additives may have potential epigenetic effects on human gut microbiota, in which several yeast species are involved. IMPORTANCE The manuscript investigates and reports for the first time utilizing a non-GMO approach to alter the fermentation process of Pinot Noir wines. We have experimentally demonstrated that certain dietary compounds possess histone deacetylase (HDAC) inhibiting activity and can alter the wine characteristics by potentially altering yeast gene transcription, which was resulted from epigenetic effects. We have previously proposed the term "nutrifermentics" to represent this newly proposed field of research that provides insights on the effect of certain dietary compounds on microbial strains and their potential application in fermentation. This technological approach is a novel way to manipulate microorganisms for innovative food and beverage production with quality attributes catering for consumer's needs. Using a multidisciplinary approach with an emphasis on food fermentation and biotechnology, this study will be substantially useful and of broad interest to food microbiologists and biotechnologists who seek for innovative concepts with real-world application potential.

Arcobacter vandammei sp. nov., isolated from the rectal mucus of a healthy pig.

A study on the polyphasic taxonomic classification of an Arcobacter strain, R-73987T, isolated from the rectal mucus of a porcine intestinal tract, was performed. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that the strain could be assigned to the genus Arcobacter and suggested that strain R-73987T belongs to a novel undescribed species. Comparative analysis of the rpoB gene sequence confirmed the findings. Arcobacter faecis LMG 28519T was identified as its closest neighbour in a multigene analysis based on 107 protein- encoding genes. Further, whole-genome sequence comparisons by means of average nucleotide identity and in silico DNA-DNA hybridization between the genome of strain R-73987T and the genomes of validly named Arcobacter species resulted in values below 95-96 and 70  %, respectively. In addition, a phenotypic analysis further corroborated the conclusion that strain R-73987T represents a novel Arcobacter species, for which the name Arcobacter vandammei sp. nov. is proposed. The type strain is R-73987T (=LMG 31429T=CCUG 75005T). This appears to be the first Arcobacter species recovered from porcine intestinal mucus.

Aliarcobacter, Halarcobacter, Malaciobacter, Pseudarcobacter and Poseidonibacter are later synonyms of Arcobacter: transfer of Poseidonibacter parvus, Poseidonibacter antarcticus, 'Halarcobacter arenosus', and 'Aliarcobacter vitoriensis' to Arcobacter as Arcobacter parvus comb. nov., Arcobacter antarcticus comb. nov., Arcobacter arenosus comb. nov. and Arcobacter vitoriensis comb. nov.

This paper re-examines the taxonomic positions of recently described Poseidonibacter (P. parvum and P. antarcticus), Aliarcobacter ('Al. vitoriensis'), Halarcobacter ('H. arenosus') and Arcobacter (A. caeni, A. lacus) species, and other species proposed to represent novel genera highly related to the genus Arcobacter. Phylogenomic and several overall genome relatedness indices (OGRIs) were applied to a total of 118 representative genomes for this purpose. Phylogenomic analyses demonstrated the Arcobacter clade to be distinct from other Epsilonproteobacteria, clearly defined and containing closely related species. Aliarcobacter butzleri and Malaciobacter pacificus did not cluster with other members of these proposed genera, indicating incoherence of these genera. Every OGRI measure applied indicated a high level of relatedness among all Arcobacter clade species, including the recently described taxa studied here, and substantially lower between type species representatives for other Epsilonproteobacteria. Where published guidelines were available, OGRI values for Arcobacter clade species were either unsupportive of division into other genera or were at the lowest boundary range (for average amino acid identity). We propose that Aliarcobacter, Halarcobacter, Malaciobacter, Pseudarcobacter, Poseidonibacter and Arcobacter sensu stricto be considered members of a single genus, Arcobacter, and subsequently transfer P. parvum, P. antarcticus, 'Al. vitoriensis' and 'H. arenosus' to Arcobacter as Arcobacter parvum comb. nov., Arcobacter antarcticus comb. nov., Arcobacter vitoriensis comb. nov. and Arcobacter arenosus comb. nov.

In silico analysis revealing CsrA roles in motility-sessility switching and tuning VBNC cells in Vibrio parahaemolyticus.

The formation of biofilms is a survival strategy employed by bacteria to help protect them from changing or unfavourable environments. In this research, 319 genes which govern biofilm formation in V. parahaemolyticus, as reported in 1,625 publications, were analysed using protein-protein-interaction (PPI) network analysis. CsrA was identified as a motility-sessility switch and biofilm formation regulator. Through robust rank aggregation (RRA) analysis of GSE65340, the generation of viable but non-culturable (VBNC) cells that may enhance cell tolerance to stress, was found to be associated with the TCA cycle and carbon metabolism biological pathways. The finding that CsrA is likely to play a role in the development of VBNC cells improves understanding of the molecular mechanisms of VBNC formation in V. parahaemolyticus and contributes to on-going efforts to reduce the hazard posed by this foodborne pathogen.

Application of MALDI-TOF analysis to reveal diversity and dynamics of winemaking yeast species in wild-fermented, organically produced, New Zealand Pinot Noir wine.

Rapid yeast identification is of particular importance in monitoring wine fermentation and assessing strain application in winemaking. We used MALDI-TOF MS analysis supported by 26 S rRNA gene sequence analysis and Saccharomyces-specific PCR testing to differentiate reference and field strains recovered from organic wine production facilities in Waipara, New Zealand, in which Pinot Noir wine was produced by spontaneous fermentations in the vineyard and in the winery. Strains were isolated from each of four key stages of each ferment to evaluate changes in taxonomic diversity. MALDI-TOF MS analysis was confirmed as an excellent yeast identification method, with even closely related Saccharomyces species readily distinguished. A total of 13 indigenous species belonging to eight genera were identified from Pinot Noir ferments, with taxonomic diversity generally reducing as fermentation progressed. However, differences between the taxa recovered were observed between the vineyard and winery ferments, despite the grapes used being from the same batch. Furthermore, some consistent proteomic differences between strains of S. cerevisiae, Hanseniasporum uvarum, Candida californica, Pichia membranifaciens and Starmerella bacillaris correlated with the different fermentation systems used. The high speed, low cost, taxonomic resolution and ability to characterise subtle changes in phenotype that may result from variations in environmental conditions makes MALDI-TOF analysis an attractive tool for further and wider applications in the wine industry. Such applications may include monitoring wine fermentation to actively support the consistency of high-quality wine products, and potentially for the development of such products too.

An emended description of Arcobacter anaerophilus Sasi Jyothsna et al. 2013: genomic and phenotypic insights.

Arcobacter anaerophilus was originally described as the first obligate anaerobe in this genus by Sasi Jyothsna et al. 2013. The complete genome sequence of the type strain of this species was determined and analysed. Genes characteristic for organisms capable of aerobic growth were identified, and the ability of the organism to grow under microaerobic and aerobic conditions was confirmed in two independent laboratories. The description of A. anaerophilus is thus emended and the wider ramifications of these findings are discussed.

Minimal standards for describing new species belonging to the families Campylobacteraceae and Helicobacteraceae: Campylobacter, Arcobacter, Helicobacter and Wolinella spp.

Ongoing changes in taxonomic methods, and in the rapid development of the taxonomic structure of species assigned to the Epsilonproteobacteria have lead the International Committee of Systematic Bacteriology Subcommittee on the Taxonomy of Campylobacter and Related Bacteria to discuss significant updates to previous minimal standards for describing new species of Campylobacteraceae and Helicobacteraceae. This paper is the result of these discussions and proposes minimum requirements for the description of new species belonging to the families Campylobacteraceae and Helicobacteraceae, thus including species in Campylobacter, Arcobacter, Helicobacter, and Wolinella. The core underlying principle remains the use of appropriate phenotypic and genotypic methods to characterise strains sufficiently so as to effectively and unambiguously determine their taxonomic position in these families, and provide adequate means by which the new taxon can be distinguished from extant species and subspecies. This polyphasic taxonomic approach demands the use of appropriate reference data for comparison to ensure the novelty of proposed new taxa, and the recommended study of at least five strains to enable species diversity to be assessed. Methodological approaches for phenotypic and genotypic (including whole-genome sequence comparisons) characterisation are recommended.

Same-day subtyping of Campylobacter jejuni and C. coli isolates by use of multiplex ligation-dependent probe amplification-binary typing.

Campylobacteriosis is the most commonly reported form of human bacterial gastroenteritis in the world. Sound identification of infectious sources requires subtyping, but the most widely used methods have turnaround times measured in days and require specialist equipment and skills. A multiplex ligation-dependent probe amplification-binary typing (MBiT) assay was developed for subtyping Campylobacter jejuni and Campylobacter coli. It was tested on 245 isolates, including recent isolates from Belgium and New Zealand, and compared to multilocus sequence typing (MLST). When used in an outbreak setting, MBiT identified the predominant genotype and possible additional cases days before pulsed-field gel electrophoresis (PFGE) results were available. MBiT was more discriminatory than MLST and, being a single assay with results produced within 6 h, was more rapid and cost-effective than both MLST and PFGE. In addition, MBiT requires only basic molecular biology equipment and skills.

Elevated abundance of Komagataeibacter results in a lower pH in kombucha production; insights from microbiomic and chemical analyses.

Kombucha consumption has grown rapidly worldwide in the last decade, with production at both small- and large scales. The complex fermentation process involves both bacterial and yeast species, but little is known regarding the progression of microbial development during production. We explored the microbial diversity of multiple batches across two kombucha types, i. e commercial scale versus laboratory-made (hereafter "home") kombucha brew using metabarcoding to characterize both fungal and bacterial communities. We found the microbial community of the commercial kombucha brew to be more complex than that of the home brew. Furthermore, PERMANOVA uncovered significant compositional differences between the bacterial (F = 2.68, R2 = 0.23, p = 00.001) and fungal (F = 3.18, R2 = 0.26, p = 00.006) communities between batches. For the home brew, both alpha and beta diversity analyses revealed no significant differences between all batches and replicates. When the microbial diversity of the home and commercial kombucha types were directly compared, the former had higher proportions of Ammoniphilus and Komagataeibacter. The commercial kombucha on the other hand were high in Anoxybacillus, Methylobacterium and Sphingomonas. For the fungal communities, the most dominant fungal genera detected in both kombucha types were similar. Linear model revealed significant correlations between some microorganisms and the sugars and organic acids assayed in this study. For example, rising glucose levels correlated with an increase in the relative abundance of Komagataeibacter (F = 7.115, Adj. R2 = 0.44, p = 00.0003). We believe these results contribute towards achieving a better control of the kombucha fermentation process and may assist in targeted product diversification.

Genotyping and Phenotyping of Indigenous Saccharomyces cerevisiae from a New Zealand Organic Winery and Commercial Sources Using Inter-Delta and MALDI-TOF MS Typing.

We used inter-delta typing (IDT) and MALDI-TOF profiling to characterize the genetic and phenotypic diversity of 45 commercially available winemaking Saccharomyces cerevisiae strains and 60 isolates from an organic winemaker from Waipara, New Zealand, as a stratified approach for predicting the commercial potential of indigenous isolates. A total of 35 IDTs were identified from the commercial strains, with another 17 novel types defined among the Waipara isolates. IDT 3 was a common type among strains associated with champagne production, and the only type in commercial strains also observed in indigenous isolates. MALDI-TOF MS also demonstrated its potential in S. cerevisiae typing, particularly when the high-mass region (m/z 2000-20,000) was used, with most indigenous strains from each of two fermentation systems distinguished. Furthermore, the comparison between commercial strains and indigenous isolates assigned to IDT 3 revealed a correlation between the low-mass data (m/z 500-4000) analysis and the recommended use of commercial winemaking strains. Both IDT and MALDI-TOF analyses offer useful insights into the genotypic and phenotypic diversity of S. cerevisiae, with MALDI-TOF offering potential advantages for the prediction of applications for novel, locally isolated strains that may be valuable for product development and diversification.

Synthesis of ß-Cyclodextrin@gold Nanoparticles and Its Application on Colorimetric Assays for Ascorbic Acid and Salmonella Based on Peroxidase-like Activities.

The peroxidase-like behaviors of gold nanoparticles (AuNPs) have the potential to the development of rapid and sensitive colorimetric assays for specific food ingredients and contaminants. Here, using NaBH4 as a reducing agent, AuNPs with a supramolecular macrocyclic compound ß-cyclodextrin (ß-CD) capped were synthesized under alkaline conditions. Monodispersal of ß-CD@AuNPs possessed a reduction in diameter size and performed great peroxidase-like activities toward both substrates, H2O2 and TMB. In the presence of H2O2, the color change of TMB oxidization to oxTMB was well-achieved using ß-CD@AuNPs as the catalyst, which was further employed to develop colorimetric assays for ascorbic acid, with a limit of detection as low as 0.2 µM in ddH2O. With the help of the host-guest interaction between ß-CD and adamantane, AuNPs conjugated with nanobodies to exhibit peroxidase-like activities and specific recognition against Salmonella Typhimurium simultaneously. Based on this bifunctional bioprobe, a selective and sensitive one-step colorimetric assay for S. Typhimurium was developed with a linear detection from 8.3 × 104 to 2.6 × 108 CFU/mL and can be provided to spiked lettuce with acceptable recoveries of 97.31% to 103.29%. The results demonstrated that the excellent peroxidase-like behaviors of ß-CD@AuNPs can be applied to develop a colorimetric sensing platform in the food industry.

Survival of Escherichia coli in Edible Land Snails: Implications for Heliciculture and Public Health.

BACKGROUND: Land snails are considered a delicacy in many countries in Europe and sub-Saharan Africa. However, the interaction of microbial pathogens with land snails may present a public health threat when handling and/or consuming snails. This study examines the survival of Escherichia coli in edible land snails in a model system. METHODS: Well-studied Shigatoxigenic (STEC) and non-STEC strains were compared. Mature Helix spp. were experimentally fed with E. coli-inoculated oats for 48 h. The snail feces after inoculation were periodically sampled and cultured for a 30-day period and subjected to microbiological analyses. RESULTS: The average rate of decline of the non-STEC strain CSH-62 in the feces of live snails was significantly (p < 0.05) faster than that of STEC ERL 06-2503. In addition, the viable population of E. coli ERL 06-2503 significantly (p < 0.05) persisted for a longer time in the intestine of land snails than E. coli CSH-62. CONCLUSION: The results showed that the viable population of the E. coli strains examined demonstrated first-order kinetics, and their survival (CFU/mL) appeared significantly (p < 0.05) dependent on the E. coli pathotype. In addition, the continuous enumeration of E. coli in snail faeces indicated that land snails could serve as a mode of transmission of microbial pathogens to susceptible hosts, including humans. Further research is recommended to better quantify the direct and indirect health risks of pathogen transmission by edible snails to humans.

Influence of climatic variation on microbial communities during organic Pinot noir wine production.

To assess the possible impact of climatic variation on microbial community composition in organic winemaking, we employed a metabarcoding approach to scrutinize the microbiome in a commercial, organic, Pinot noir wine production system that utilizes autochthonous fermentation. We assessed microbial composition across two vintages (2018 and 2021) using biological replicates co-located at the same winery. Microbial dynamics were monitored over four important fermentation time points and correlated with contemporaneous climate data. Bacterial (RANOSIM = 0.4743, p = 0.0001) and fungal (RANOSIM = 0.4738, p = 0.0001) compositions were different in both vintages. For bacteria, Lactococcus dominated the diversity associated with the 2018 vintage, while Tatumella dominated the 2021 vintage. For fungal populations, while Saccharomyces were abundant in both vintages, key differences included Starmerella, copious in the 2018 vintage; and Metschnikowia, substantive in the 2021 vintage. Ordination plots correlated the climatic variables with microbial population differences, indicating temperature as a particularly important influence; humidity values also differed significantly between these vintages. Our data illustrates how climatic conditions may influence microbial diversity during winemaking, and further highlights the effect climate change could have on wine production.

Environmental influences on microbial community development during organic pinot noir wine production in outdoor and indoor fermentation conditions.

The role of microbial diversity in influencing the organoleptic properties of wine and other fermented products is well est ablished, and understanding microbial dynamics within fermentation processes can be critical for quality assurance and product innovation. This is especially true for winemakers using spontaneous fermentation techniques, where environmental factors may play an important role in consistency of product. Here, we use a metabarcoding approach to investigate the influence of two environmental systems used by an organic winemaker to produce wines; vineyard (outdoors) and winery (indoors) to the bacterial and fungal communities throughout the duration of a spontaneous fermentation of the same batch of Pinot Noir grapes. Bacterial (RANOSIM = 0.5814, p = 0.0001) and fungal (RANOSIM = 0.603, p = 0.0001) diversity differed significantly across the fermentation stages in both systems. Members of the Hyphomicrobium genus were found in winemaking for the first time, as a bacterial genus that can survive alcoholic fermentation. Our results also indicate that Torulaspora delbrueckii and Fructobacillus species might be sensitive to environmental systems. These results clearly reflect the substantial influence that environmental conditions exert on microbial populations at every point in the process of transforming grape juice to wine via fermentation, and offer new insights into the challenges and opportunities for wine production in an ever-changing global climate.

Efficacy of commercial peroxyacetic acid on Vibrio parahaemolyticus planktonic cells and biofilms on stainless steel and Greenshell™ mussel (Perna canaliculus) surfaces.

The potential of using commercial peroxyacetic acid (PAA) for Vibrio parahaemolyticus sanitization was evaluated. Commercial PAA of 0.005 % (v/v, PAA: 2.24 mg/L, hydrogen peroxide: 11.79 mg/L) resulted in a planktonic cell reduction of >7.00 log10 CFU/mL when initial V. parahaemolyticus cells averaged 7.64 log10 CFU/mL. For cells on stainless steel coupons, treatment of 0.02 % PAA (v/v, PAA: 8.96 mg/L, hydrogen peroxide: 47.16 mg/L) achieved >5.00 log10 CFU/cm2 reductions in biofilm cells for eight strains but not for the two strongest biofilm formers. PAA of 0.05 % (v/v, PAA: 22.39 mg/L, hydrogen peroxide: 117.91 mg/L) was required to inactivate >5.00 log10 CFU/cm2 biofilm cells from mussel shell surfaces. The detection of PAA residues after biofilm treatment demonstrated that higher biofilm production resulted in higher PAA residues (p < 0.05), suggesting biofilm is acting as a barrier interfering with PAA diffusing into the matrices. Based on the comparative analysis of genomes, robust biofilm formation and metabolic heterogeneity within niches might have contributed to the variations in PAA resistance of V. parahaemolyticus biofilms.