Relative contribution of sensory characteristics for different types of pork loin, assessed by temporal dominance of sensations.

BACKGROUND: Sensory perception is a dynamic process occurring sequentially. The dynamic analysis of the perception of sensory characteristics in meat is important to understand complex meat sensory characteristics. Temporal dominance of sensations (TDS) is a dynamic sensory method that captures the 'dominance of sensations' throughout food consumption, and it is possible to calculate the relative contribution of various sensory characteristics by 'dominance rate' over time. The objective of this study was to assess the major sensory characteristics of the dynamic sensory perception of pork loin. Using the TDS, we evaluated pork loins derived from pigs with different genetic and feeding backgrounds. Moreover, we checked the integrity of the TDS by comparing the TDS results with a descriptive sensory analysis and a physico-chemical analysis. RESULTS: Seven types of pork loin were evaluated by TDS, and 'tender and/or soft,' 'tough and/or hard,' 'juicy,' 'dry,' 'fat melting,' 'smoothness,' 'sourness,' 'umami,' and 'beast odors' became dominant in at least one type of pork loin. The dynamics of the perception of pork sensory characteristics was also depicted by TDS. In addition, TDS and descriptive analysis demonstrated similarity in principal component analysis. CONCLUSION: TDS demonstrated the major sensory characteristics on the dynamic sensory perception of pork loin. © 2019 Society of Chemical Industry.

Identification of the Q969R gain-of-function polymorphism in the gene encoding porcine NLRP3 and its distribution in pigs of Asian and European origin.

The nucleotide-binding domain, leucine-rich-containing family, pyrin-domain containing-3 (NLRP3) inflammasome comprises the major components caspase-1, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), and NLRP3. NLRP3 plays important roles in maintaining immune homeostasis mediated by intestinal microorganisms and in the immunostimulatory properties of vaccine adjuvants used to induce an immune response. In the present study, we first cloned a complementary DNA (cDNA) encoding porcine ASC because its genomic sequence was not completely determined. The availability of the ASC cDNA enabled us to reconstitute porcine NLRP3 inflammasomes using an in vitro system that led to the identification of the immune functions of porcine NLRP3 and ASC based on the production of interleukin-1ß (IL-1ß). Further, we identified six synonymous and six nonsynonymous single-nucleotide polymorphisms (SNPs) in the coding sequence of NLRP3 of six breeds of pigs, including major commercial breeds. Among the nonsynonymous SNPs, the Q969R polymorphism is associated with an increased release of IL-1ß compared with other porcine NLRP3 variants, indicating that this polymorphism represents a gain-of-function mutation. This allele was detected in 100 % of the analyzed Chinese Jinhua and Japanese wild boars, suggesting that the allele is maintained in the major commercial native European breeds Landrace, Large White, and Berkshire. These findings represent an important contribution to our knowledge of the diversity of NLRP3 nucleotide sequences among various pig populations. Moreover, efforts to exploit the gain of function induced by the Q969R polymorphism promise to improve pig breeding and husbandry by conferring enhanced resistance to pathogens as well as contributing to vaccine efficacy.

Paenibacillus silagei sp. nov. isolated from corn silage.

A Gram-stain-negative, rod-shaped, endospore-forming bacterium, strain LOOC204T, was isolated from corn silage that had been prepared and stored in Hokkaido, Japan. The isolate grew well at 4-37 °C and at pH 6.0-8.5. The major cellular fatty acids were anteiso-C15 : 0, C16 : 0, iso-C14 : 0 and iso-C16 : 0. The major menaquinone was MK-7. Diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, three unidentified aminophospholipids, one unidentified phospholipid, two unidentified aminolipids and three unidentified lipids were detected as the cellular polar lipids. The genomic DNA G+C content of LOOC204T was 52.2±0.7 mol%. A comparative 16S rRNA gene sequence analysis showed that LOOC204T represented a member of the genus Paenibacillus, and high levels of sequence similarity of LOOC204T with Paenibacillus borealis KK19T (97.5 %) and Paenibacillusjilunlii Be17T (97.4 %) were found. Based on sequence analysis of the RNA polymerase ß subunit (rpoB) gene, LOOC204T was clearly separated from its phylogenetic neighbors in the genus Paenibacillus. DNA-DNA hybridisation experiments showed that LOOC204T displayed less than 40 % reassociation values toward its nearest phylogenetic neighbours of the genus Paenibacillus, indicating the unique taxonomic status of LOOC204T. Based on these data, we conclude that strain LOOC204T represents a novel species of the genus Paenibacillus, named Paenibacillus silageisp. nov. The type strain is LOOC204T (=JCM 30974T=DSM 101953T).

Lactobacillus mixtipabuli sp. nov. isolated from total mixed ration silage.

Using a polyphasic taxonomic approach, we investigated three bacterial strains - IWT30T, IWT8 and IWT75 - isolated from total mixed ration silage prepared in Hachimantai, Iwate, Japan. The isolates comprised Gram-stain positive, non-motile, non-spore-forming, catalase-negative, rod-shaped bacteria. Good growth occurred at 15-45 °C and at pH 4.0-7.5. Their major cellular fatty acids were C18:1ω9c and C19:1 cyclo 9,10.The G+C content of genomic DNA of strain IWT30T was 44.6 mol%. Comparative 16S rRNA gene sequence analysis showed that these novel strains belonged to the genus Lactobacillus. These strains shared 100 % 16S rRNA gene sequence similarity and were most closely related to the type strains of Lactobacillus silagei, Lactobacillus odoratitofui, Lactobacillus similis, Lactobacillus collinoides, Lactobacillus paracollinoides and Lactobacillus kimchicus, with sequence similarity values of 99.5, 98.8, 98.7, 97.8, 97.8 and 96.8 %, respectively. The level of DNA-DNA relatedness between these strains and their closest phylogenetic neighbours was less than 30 %. On the basis of additional phylogenetic analysis of pheS and rpoA gene sequences and phenotypic and chemotaxonomic characteristics, we conclude that these three strains represent a novel species of the genus Lactobacillus, for which we propose the name Lactobacillus mixtipabuli sp. nov. The type strain is IWT30T ( = JCM 19805T = DSM 28580T).

Aerococcus vaginalis sp. nov., isolated from the vaginal mucosa of a beef cow, and emended descriptions of Aerococcus suis, Aerococcus viridans, Aerococcus urinaeequi, Aerococcus urinaehominis, Aerococcus urinae, Aerococcus christensenii and Aerococcus sanguinicola.

A gram-stain-positive, facultatively anaerobic, non-spore-forming, catalase-negative, coccoid-shaped bacterial strain, designated BV2(T), was isolated from the vaginal mucosa of a beef cow in Japan. Phylogenetic analysis showed that the isolate shared high 16S rRNA gene sequence similarity (92.9 %) with Aerococcus suis 1821/02(T) and low similarity (<92.7 %) with any other recognized species of the genus Aerococcus. The DNA G+C content was 44.7 mol%, which is within the range observed among species of the genus Aerococcus (37.5-48.4 mol%). The major cellular fatty acid was C18 : 1ω9c, similar to other type strains of species of the genus Aerococcus. The results of genotypic, phenotypic and chemotaxonomic analyses as well as the low degree of DNA-DNA relatedness with all recognized members of the genus Aerococcus indicate that strain BV2(T) represents a novel species of the genus Aerococcus, for which the name Aerococcus vaginalis sp. nov. is proposed. The type strain is BV2(T) ( = JCM 19163(T) = DSM 27293(T)). Emended descriptions of Aerococcus suis, Aerococcus viridans, Aerococcus urinaeequi, Aerococcus urinaehominis, Aerococcus urinae, Aerococcus christensenii and Aerococcus sanguinicola are also presented.

Lactobacillus hokkaidonensis sp. nov., isolated from subarctic timothy grass (Phleum pratense L.) silage.

Four strains of Gram-positive, non-spore-forming, rod-shaped, catalase-negative and non-motile lactic acid bacteria, LOOC260(T), LOOC253, LOOC273 and LOOC279, were isolated from timothy grass (Phleum pratense L.) silage produced in Hokkaido, a subarctic region of Japan. These isolates grew at 4-37 °C, indicating the psychrotolerant nature of these strains. Phylogenetic analysis on the basis of 16S rRNA and pheS gene sequences, as well as biochemical and physiological characteristics, indicated that these four strains were members of the genus Lactobacillus. 16S rRNA gene sequence analysis of strain LOOC260(T) demonstrated that the closest neighbours were the type strains of Lactobacillus suebicus (97.7 %), Lactobacillus oligofermentans (96.7 %) and Lactobacillus vaccinostercus (96.7 %). Strain LOOC260(T) showed low levels of DNA-DNA association with Lactobacillus suebicus JCM 9504(T) (14.7 ± 3.5 %), Lactobacillus oligofermentans JCM 16175(T) (15.1 ± 4.8 %) and Lactobacillus vaccinostercus JCM 1716(T) (10.7 ± 3.0 %). The cell wall contained meso-diaminopimelic acid and the major fatty acids were C18 : 1ω9c and C19 : 1 cyclo 9,10. On the basis of phenotypic, physiological and phylogenetic evidence, these isolates represent a novel species of the genus Lactobacillus, for which the name Lactobacillus hokkaidonensis sp. nov. is proposed. The type strain is LOOC260(T) ( = JCM 18461(T) = DSM 26202(T)).

Lactobacillus oryzae sp. nov., isolated from fermented rice grain (Oryza sativa L. subsp. japonica).

The taxonomic position of three Lactobacillus-like micro-organisms (strains SG293(T), SG296 and SG310) isolated from fermented rice grain (Oryza sativa L. subsp. japonica) in Japan was investigated. These heterofermentative lactic acid bacteria were Gram-stain-positive, rod-shaped, facultatively anaerobic, non-motile, non-spore-forming and did not show catalase activity. 16S rRNA gene sequence analysis of strain SG293(T) revealed that the type strains of Lactobacillus malefermentans (98.3 %), Lactobacillus odoratitofui (96.2 %), Lactobacillus similis (96.1 %), Lactobacillus kimchicus (96.1 %), Lactobacillus paracollinoides (95.9 %) and Lactobacillus collinoides (95.7 %) were the closest neighbours. Additional phylogenetic analysis on the basis of pheS and rpoA gene sequences, as well as biochemical and physiological characteristics, indicated that these three strains were members of the genus Lactobacillus and that the novel isolates had a unique taxonomic position. The predominant cellular fatty acids were C18 : 1ω9c and C19 : 1 cyclo 9,10. Because low DNA-DNA hybridization values among the isolates and Lactobacillus malefermentans JCM 12497(T) were observed, it is proposed that these unidentified isolates be classified as a novel species of the genus Lactobacillus, Lactobacillus oryzae sp. nov. The type strain is SG293(T) (= JCM 18671(T) = DSM 26518(T)).

Weissella oryzae sp. nov., isolated from fermented rice grains.

A taxonomic study was conducted on two Gram-reaction-positive, catalase-negative, irregular short-rod-shaped or coccoid lactic acid bacteria, designated strains SG25(T) and SG23, that were isolated from grains of fermented Japanese rice (Oryza sativa L. subsp. japonica). A phylogenetic analysis based on 16S rRNA gene sequence data clearly showed that the strains belonged to the genus Weissella and were most closely related to Weissella soli LMG 20113(T) (with a sequence similarity of 96.9 % for each novel strain). The peptidoglycan of each strain contained the amino acids glutamic acid, lysine, serine and alanine in a molar ratio of 1.0 : 1.2 : 0.5 : 3.0, respectively. On the basis of the unusual phenotypic characteristics of the novel strains and the low levels of DNA-DNA relatedness recorded between each novel strain and Weissella soli JCM 12536(T), strains SG25(T) and SG23 represent a single novel species in the genus Weissella, for which the name Weissella oryzae sp. nov. is proposed. The type strain is SG25(T) ( = JCM 18191(T)  = DSM 25784(T)).

Description of Lactobacillus iwatensis sp. nov., isolated from orchardgrass (Dactylis glomerata L.) silage, and Lactobacillus backii sp. nov.

Two bacterial strains, designated IWT246(T) and IWT248, were isolated from orchardgrass (Dactylis glomerata L.) silage from Iwate prefecture, Japan, and examined for a taxonomic study. Both organisms were rod-shaped, Gram-stain-positive, catalase-negative, facultatively anaerobic and homofermentative. The cell wall did not contain meso-diaminopimelic acid and the major fatty acids were C18 : 1ω9c and C19 cyclo 9,10/:1. Comparative analyses of 16S rRNA, pheS and rpoA gene sequences revealed that these strains were novel and belonged to the genus Lactobacillus. Based on 16S rRNA gene sequence similarity, the isolates were most closely related to the type strains of the following members of the genus Lactobacillus: Lactobacillus coryniformis subsp. coryniformis (96.7 % similarity), L. coryniformis subsp. torquens (96.6 %), L. bifermentans (95.5 %) and L. rennini (94.1 %). However, the 16S rRNA gene sequences of both IWT246(T) and IWT248 were 99.7 % similar to that of 'Lactobacillus backi' JCM 18665; this name has not been validly published. Genotypic, phenotypic and chemotaxonomic analyses confirmed that these novel strains occupy a unique taxonomic position. DNA-DNA hybridization experiments demonstrated genotypic separation of the novel isolates from related Lactobacillus species. The name Lactobacillus iwatensis sp. nov. is proposed for the novel isolates, with strain IWT246(T) ( = JCM 18838(T) = DSM 26942(T)) as the type strain. Our results also suggest that 'L. backi' does represent a novel Lactobacillus species. The cells did not contain meso-diaminopimelic acid in their cell-wall peptidoglycan and the major fatty acids were C16 : 0, C19 cyclo 9,10/:1 and summed feature 10 (one or more of C18 : 1ω11c, C18 : 1ω9t, C18 : 1ω6t and unknown ECL 17.834). We therefore propose the corrected name Lactobacillus backii sp. nov., with the type strain JCM 18665(T) ( = LMG 23555(T) = DSM 18080(T) = L1062(T)).

Lactobacillus silagei sp. nov., isolated from orchardgrass silage.

A Gram-reaction-positive, facultatively anaerobic, non-spore-forming and catalase-negative rod-shaped bacterial strain, designated IWT126(T), was isolated from orchardgrass (Dactylis glomerata L.) silage preserved in Hachimantai, Iwate, Japan. The isolate showed growth at 15-45 °C, pH 3.5-7.5 and with 4.0 % (w/v) NaCl. The cell wall peptidoglycan did not contain meso-diaminopimelic acid, and the DNA G+C content was 45.6 mol%. The major cellular fatty acids were C16 : 0 and C19 : 1 cyclo 9,10. Based on 16S rRNA gene sequence similarity, strain IWT126(T) was classified as a member of the genus Lactobacillus and was most closely related to Lactobacillus odoratitofui YIT 11304(T) (98.7 %), Lactobacillus similis JCM 2765(T) (98.5 %), Lactobacillus collinoides JCM 1123(T) (97.6 %), Lactobacillus paracollinoides DSM 15502(T) (97.6 %) and Lactobacillus kimchicus DCY51(T) (96.9 %). Based on sequence analysis of the phenylalanyl-tRNA synthase α-subunit (pheS) gene, strain IWT126(T) was well separated from its phylogenetic neighbours in the genus Lactobacillus. Based on physiological, biochemical and genotypic results, as well as low DNA-DNA relatedness to recognized phylogenetic relatives in the genus Lactobacillus, classification of strain IWT126(T) as a representive of a novel species named Lactobacillus silagei sp. nov. is proposed. The type strain is IWT126(T) ( = JCM 19001(T) = DSM 27022(T)).

Segmented filamentous bacteria are a major group in terminal ileum of piglets.

Metabolically active microbiota of the porcine terminal ileum mucosa was analyzed by RT-PCR of 16S rRNAs. The majority of 1951 sequences retrieved (24.8%) displayed the closest similarity to segmented filamentous bacteria (SFB). Phylogenetic analysis inferred the host-specific clusters of SFB sequences suggesting the host-specific selection of this group of bacteria.

An rRNA-based analysis for evaluating the effect of heat stress on the rumen microbial composition of Holstein heifers.

We performed a set of heifer feeding trials to investigate the effect of heat and humidity stresses on the rumen bacterial molecular diversity of Holstein heifers (Tajima K, Nonaka I, Higuchi K, Takusari N, Kurihara M, Takenaka A, et al. Anaerobe 2007;13:57-64). To further characterize the response of the microbial community to the physiological changes caused by the stresses, we evaluated changes in the ruminal bacterial community composition in the same trials by applying an RNA-based method (sequence-specific small-subunit (SSU) rRNA cleavage method), which was optimized for a comprehensive description of the predominant bacterial groups inhabiting the rumen. Four Holstein heifers were kept at three temperatures (20 degrees C, 28 degrees C, 33 degrees C) in a climatic chamber for two weeks each, and rumen fluid samples were obtained on the last day of each temperature experiment. For quantitative detection, we applied a set of 15 oligonucleotide probes, including those targeting taxa comprised of uncultured rumen bacteria (URB) belonging to phylum Firmicutes, to the RNAs extracted from the fluid samples. The relative populations of the Clostridium coccoides-Eubacterium rectale group, and the genus Streptococcus increased, and that of the genus Fibrobacter decreased in response to increasing temperature both in the first (nine months old, 80% relative humidity) and second (15 months old, 60% relative humidity) experiments. In addition, the population of a defined URB group was higher at 33 degrees C than at 20 degrees C in the second trial, whereas one of the other URB groups showed a decreasing trend with the temperature rise. These results indicate that the exposure to heat affects the population levels of specific bacterial groups in the ruminal microbial community.

Fermented liquid feed enhances bacterial diversity in piglet intestine.

Because of limitations imposed on the antibiotic use in animal industry, there is a need for alternatives to maintain the efficiency of production. One of them may be the use of fermented liquid feed (FLF) but how it affects gut ecology is poorly understood. We investigated the effect of three diets, standard dry feed (control), dry feed supplemented with antibiotics, and fermented liquid feed (FLF, fermented with Lactobacillus plantarum), on gut bacterial diversity in piglets. The structure of the ileal and caecal communities was estimated by sequencing the SSU rRNA gene libraries. Antibiotic-supplemented feed slightly increased bacterial diversity in the ileum but reduced it in the caecum while in FLF-fed animals bacterial diversity was elevated. The majority of bacterial sequences in the ileum of all three groups belonged to lactobacilli (92-98%). In the caecum the lactobacilli were still dominant in control and antibiotic-fed animals (59% and 64% of total bacterial sequences, respectively) but in FLF-fed animals they fell to 31% with the concomitant increase in the Firmicutes diversity represented by the Dorea, Coprococcus, Roseburia and Faecalibacterium genera. Thus FLF affects the gut ecology in a different way than antibiotics and contributes to the enhanced bacterial diversity in the gastrointestinal tract.

Three-dimensional finite element modeling from CT images of tooth and its validation.

The aim of this study was to develop a three-dimensional (3D) finite element (FE) model of a sound extracted human second premolar from micro-CT data using commercially available software tools. A detailed 3D FE model of the tooth could be constructed and was experimentally validated by comparing strains calculated in the FE model with strain gauge measurement of the tooth under loading. The regression coefficient and its standard error in the regression analysis between strains calculated by the FE model and measured with strain gauge measurement were 0.82 and 0.06, respectively, and the correlation coefficient was found to be highly significant. These results suggested that an FE model reconstructed from micro-CT data could be used as a valid model to estimate the actual strains with acceptable accuracy.

Diversity of the formyltetrahydrofolate synthetase gene (fhs), a key enzyme for reductive acetogenesis, in the bovine rumen.

A clone library of the partial formyltetrahydrofolate synthetase gene (fhs), a key enzyme in reductive acetogenesis, was constructed from the DNA of bovine rumen contents. Diverse sequences were recovered, the majority of which were clustered with the fhs of authentic acetogens. Low similarity values to known fhs were observed in all sequences, suggesting the presence of unknown acetogens.

Reduction of chlortetracycline-resistant Escherichia coli in weaned piglets fed fermented liquid feed.

We investigated the change in chlortetracycline resistance in 360 Escherichia coli strains separated from the feces of piglets fed fermented liquid feed (FLF) in comparison with those fed dry feed (control). The total amount of lactic acid bacteria in feces was 8.77 x 10(8) CFU/g DM at weaning, which increased to 1.23 x 10(12) CFU/g DM (FLF) at 28 days after weaning (P<0.001). As a result of the antibiotic susceptibility test, almost all isolates were chlortetracycline-resistant (CTCR) until 14 days after weaning both in the FLF and control groups. At 28 days, the CTCR E. coli decreased to 22.2% in the FLF group, while the proportion of resistant bacteria was 88.9% in the control group. In addition, as a result of the gene analysis, it was clarified that there is a relation between the decrease in the minimum inhibitory concentration values and the possession rate of the tetracycline-resistance gene tet(A), tet(B) and tet(D). These results show that FLF caused an increase in the number of lactic acid bacteria in the intestines, and suggested that the feeding of FLF can possibly reduce antibiotic-resistance bacteria.

Electropolishing of CP titanium and its alloys in an alcoholic solution-based electrolyte.

A newly developed electropolishing system, equipped with an original agitation function for an electrolyte and using a safe electrolyte composed of an alcoholic solution, was applied for wrought and cast CP titanium and its alloys. Surface roughness and morphology of the polished surfaces were then examined. Under an electrolytic condition of 70-75 V, 2.0 kA/m2, and 30 degrees C, wrought CP Ti and Ti-6Al-4V alloy achieved an apparent mirror-like finishing with an average surface roughness (Ra) of 0.03 and 0.12 microm respectively. Under the same condition, on the other hand, cast CP Ti and Ti-6Al-7Nb alloy produced rougher polished surfaces with average Ra values of 0.67-0.80 microm, and the finishing was apparently shiny, but not mirror-like. SEM observation of the polished surfaces showed that wrought CP Ti was even and completely featureless, while wrought Ti-6Al-4V alloy was pitted. For cast CP Ti, a needle-like phase containing traces of iron was observed on the polished surface.

Complete Genome Sequence of Lactobacillus plantarum Strain LQ80, Selected for Preparation of Fermented Liquid Feed for Pigs.

Lactobacillus plantarum LQ80 is a strain isolated from liquid feed for pigs. We determined the complete genome sequence of this strain using the PacBio RS II platform. LQ80 contained a single circular chromosome of 3,230,192 bp, with 44.66% G+C content and seven plasmids.

Intensity of singular stress fields of wedge-shaped defect in human tooth due to occlusal force before and after restoration with composite resins.

Wedge-shaped defects are frequently observed on the cervical region of the human tooth. Previously, most studies explained that improper tooth-brushing causes such defects. However, recent clinical observation suggested that the repeated stress due to occlusal force may induce the formation of these wedge-shaped defects. In this study, therefore, two-dimensional human tooth models are considered with and without a wedge-shaped defect by applying the finite element method. To evaluate large stress concentrations accurately, a method of analysis is discussed in terms of the intensity of singular stress fields appearing at the tip of the sharp wedge-shaped defect. The effects of the position and direction of occlusion on the intensity of singular stress fields are discussed before and after restoration with composite resins.

Possible quorum sensing in the rumen microbial community: detection of quorum-sensing signal molecules from rumen bacteria.

The bioluminescence assay using Vibrio harveyi BB170 was used to examine quorum-sensing autoinducer 2 (AI-2) activity from cell-free culture fluids of rumen bacteria. The assay showed that the culture fluids of four species of rumen bacteria, Butyrivibrio fibrisolvens, Eubacterium ruminantium, Ruminococcus flavefaciens, and Succinimonas amylolytica, contained AI-2-like molecules. Furthermore, homologues for luxS genes were detected in rumen fluids collected from three cows and in bacterial cells of P. ruminicola subsp. ruminicola and R. flavefaciens. These findings suggest that the quorum-sensing system mediated by AI-2 is present in the rumen.