Methanooceanicella nereidis gen. nov., sp. nov., the first oceanic Methanocellaceae methanogen, isolated from potential methane hydrate bearing area offshore southwestern Taiwan.

A novel mesophilic, hydrogenotrophic methanogen, strain CWC-04T, was obtained from a sediment sample extracted from a gravity core retrieved at station 22 within the KP-9 area off the southwestern coast of Taiwan during the ORIII-1368 cruise in 2009. Cells of strain CWC-04T were rod-shaped, 1.4-2.9 µm long by 0.5-0.6 µm wide, and occurred singly. Strain CWC-04Tutilized formate, H2/CO2, 2-propanol/CO2 or 2-butanol/CO2 as catabolic substrates. The optimal growth conditions were 42 °C, 0.17 M NaCl and pH 5.35. The genomic DNA G+C content calculated from the genome sequence of strain CWC-04T was 46.19 mol%. Phylogenetic analysis of 16S rRNA gene revealed that strain CWC-04T is affiliated with the genus Methanocella. The 16S rRNA gene sequences similarities within strains Methanocella arvoryzae MRE50T, Methanocella paludicola SANAET and Methanocella conradii HZ254T were 93.7, 93.0 and 91.3 %, respectively. In addition, the optical density of CWC-04T culture dropped abruptly upon entering the late-log growth phase, with virus-like particles (150 nm in diameter) being observed on and around the cells. This observation suggests that strain CWC-04T harbours a lytic virus. Based on these phenotypic, phylogenetic and genomic results, we propose that strain CWC-04T represents a novel species of a novel genus in the family Methanocellaceae, for which the name Methanooceanicella nereidis gen. nov., sp. nov. is proposed. The type strain is CWC-04T (=BCRC AR10050T=NBRC 113165T).

Core food model of the Taiwan food supply for total diet study.

Following the core food (CF) models of the USA and France reported in the 2000s, this study presents the first oriental CF model, for total diet studies in Taiwan. First, we combined the four latest national dietary recall surveys from 2005 to 2012, data sets from the Nutrition and Health Survey in Taiwan (NAHSIT) covering all ages (1 to 65+ years old). In total, 3,098 NAHSIT food codes from 349,497 records of responses from 7,580 individuals were aggregated within a three-tiered scheme into 237 CFs in 54 subcategories and 16 categories. As with Western foods, Taiwanese foods were mainly aggregated by food type and major ingredient, processing method, cooking method or serving habit. In addition, we propose several categories typical to Taiwanese foods: (1) processed foods (e.g. rice paste, rice noodle, bean curd); (2) mixed foods (e.g. tomato fried with egg, Guangdong porridge) and stuffed staple foods (e.g. rice cake, zongzi); (3) Chinese Dim Sum (e.g. dumpling, salted bun); and (4) animal offal (e.g. pig liver, chicken kidney) and by-products (e.g. chicken head, pig foot). Systematic nomenclature and coding methods are also proposed. A computerised web model was developed using a graphical user interface (GUI) for automatic CF aggregation and inquiry of various consumption estimates according to the residing area, age group, and gender of consumers. Point estimates of weighted means were calculated for consumption rates (CR) based on the whole group (WG) or consumers only (CO). The CR and body weight (BW) of each individual were matched to calculate mean intake per unit body weight (g/kg bw/day). A general sample design procedure with the CF model is suggested for a total diet study (TDS) on target hazards. Strategies are also discussed for improving the quality of food matching in sample designs.

A study to evaluate the potential of an in silico approach for predicting dipeptidyl peptidase-IV inhibitory activity in vitro of protein hydrolysates.

A total of 294 edible protein sequences and 5 commercial proteases listed in the BIOPEP database were analyzed in silico. The frequency (A), a parameter in silico described previously, was examined further to calculating the ratio of truncated peptides with Xaa-proline and/or Xaa-alanine to all peptide fragments in a protein hydrolyzed with a protease, using the BIOPEP database. Then the in vitro DPP-IV inhibitory activity was determined using the same 15 protein and protease combinations to evaluate their relationship. The result shows that A values considering the number of Xaa-proline+Xaa-alanine exhibited a strong correlation with in vitro DPP-IV inhibition rates by Pearson's correlation analysis (r=0.6993; P<0.05). Therefore, the in silico approach is effective to predict DPP-IV inhibitory activities in vitro of protein hydrolysates.

Isolation of prolyl endopeptidase inhibitory peptides from a sodium caseinate hydrolysate.

Prolyl endopeptidase (PEP) has been associated with neurodegenerative disorders, and the PEP inhibitors can restore the memory loss caused by amnesic compounds. In this study, we investigated the PEP inhibitory activity of the enzymatic hydrolysates from various food protein sources, and isolated and identified the PEP inhibitory peptides. The hydrolysate obtained from sodium caseinate using bromelain (SC/BML) displayed the highest inhibitory activity of 86.8% at 5 mg mL(-1) in the present study, and its IC50 value against PEP was 0.77 mg mL(-1). The F-5 fraction by RP-HPLC (reversed-phase high performance liquid chromatography) from SC/BML showed the highest PEP inhibition rate of 88.4%, and 9 peptide sequences were identified. The synthetic peptides (1245.63-1787.94 Da) showed dose-dependent inhibition effects on PEP as competitive inhibitors with IC50 values between 29.8 and 650.5 µM. The results suggest that the peptides derived from sodium caseinate have the potential to be PEP inhibitors.

In silico, in vitro and in vivo analyses of dipeptidyl peptidase IV inhibitory activity and the antidiabetic effect of sodium caseinate hydrolysate.

The frequency (A), a novel in silico parameter, was developed by calculating the ratio of the number of truncated peptides with Xaa-proline and Xaa-alanine to all peptide fragments from a protein hydrolyzed with a specific protease. The highest in vitro DPP-IV inhibitory activity (72.7%) was observed in the hydrolysate of sodium caseinate by bromelain (Cas/BRO), and the constituent proteins of bovine casein also had relatively high A values (0.10-0.17) with BRO hydrolysis. 1CBR (the <1 kDa fraction of Cas/BRO) showed the greatest in vitro DPP-IV inhibitory activity of 77.5% and was used for in vivo test by high-fat diet-fed and low-dose streptozotocin-induced diabetic rats. The daily administration of 1CBR for 6 weeks was effective to improve glycaemic control in diabetic rats. The results indicate that the novel in silico method has the potential as a screening tool to predict dietary proteins to generate DPP-IV inhibitory and antidiabetic peptides.

The development of bioactive peptides from dietary proteins as a dipeptidyl peptidase IV inhibitor for the management of type 2 diabetes.

One of the new approaches to the management of type 2 diabetes mellitus (T2DM) consists of orally administered dipeptidyl peptidase-IV (DPP-IV) inhibitors. These synthetic drug inhibitors are reported to have some side effects and that subsequently limits their applications. There is a growing interest to develop natural DPP-IV inhibitors that will be potent without undesirable side effects. Many in vitro and some in vivo studies have highlighted the potential of food-derived peptides functioning as effective DPPIV inhibitors. Bioactive peptides within original food-derived proteins are inactive but can be activated by being released during food processing (by enzymatic hydrolysis or fermentation) or during gastrointestinal digestion. Hence, the utilization of computer-aided techniques as screening tools may be helpful in predicting the potential of food proteins as precursors of DPP-IV inhibitory peptides. This paper reviews the current literature on DPP-IV inhibitory peptides, focusing on their in vitro activity and in vivo antidiabetic effects. In addition, the feasibility of various in silico approaches is also summarized in this review.

The phylogenetic analysis and putative function of lysine 2,3-aminomutase from methanoarchaea infers the potential biocatalysts for the synthesis of ß-lysine.

BACKGROUND: ß-amino acids play important biological roles as precursors in the biosynthesis of antibiotics, anticancer agents, neurotransmitters, and other high molecular weight polymers. Microbial cells and enzymes from extreme environments offer new opportunities for biocatalysis and biotransformations as a result of their extreme stability. Lysine 2,3-aminomutase catalyzes the interconversion of L-α-lysine and L-ß-lysine. L-ß-lysine is a precursor in the bacterial biosynthesis of several antibiotics, and also is a precursor in the biosynthesis of osmolyte N(ε)-acetyl-ß-lysine for salt stress and adaptation in methanoarchaea. METHODS: Lysine 2,3-aminomutase (AblA) genes from the marine Methanosarcina mazei N2M9705, halotolerant Methanocalculus chunghsingensis K1F9705b(T), and halophilic Methanohalophilus portucalensis FDF1(T) were cloned by PCR and southern hybridization. Both nucleotide and amino acid sequences of AblAs were analyzed and phylogenetic comparisons performed. Additionally, the functional motifs and 3D structure of aminomutases were aligned and compared. RESULTS: The deduced amino acid sequences of AblAs from methanoarchaea share high identity with the known clostridial and Bacillus lysine 2,3-aminomutase. The conserved amino acid residues for cofactors, such as the iron-sulfur cluster, S-adenosylmethionine (SAM), pyridoxal 5'-phosphate (PLP) and zinc-binding sites in methanoarchaeal AblAs suggested that they were lysine 2,3-aminomutases. CONCLUSION: AblAs from methanoarchaea are lysine 2,3-aminomutases that may function as potential biocatalysts for the synthesis of ß-lysine in vivo and in vitro.

The fatigue experience of haemodialysis patients in Taiwan.

AIMS AND OBJECTIVES: To expand the theoretical understanding of fatigue, this study used in-depth interview to explore the fatigue experience from haemodialysis patients' perspectives. BACKGROUND: Fatigue is a common symptom experienced by the people with chronic diseases including those with renal failure requiring haemodialysis. METHODS: Data were collected in a haemodialysis unit of a hospital in South Taiwan. Purposive samples of 14 participants were interviewed in-depth. Colaizzi's methods were used to analyse transcripts of the interviews. RESULTS: Ten themes were delineated and classified into three domains. The first domain 'physical fatigue' consists of four themes: (1) habitual fatigue, (2) experiencing the uraemic symptoms (3) suffering from sleeping disturbance, (4) insufficient physical energy. The second domain 'affective fatigue' contains three themes: (5) detesting long-term treatment, (6) perceiving depression (7) and feeling exhausted. The third domain 'cognitive fatigue' includes three themes: (8) regretting lost cognition, (9) intentional isolation and (10) coping with fatigue. CONCLUSIONS: The findings identify that fatigue is a multi-dimensional concept. By understanding the various aspects of fatigue, nurses may be better able to plan and provide fatigue-relieving strategies for haemodialysis patients. RELEVANCE TO CLINICAL PRACTICE: The results can provide a direction for interventional studies designed to reduce the patients' fatigue.