The potential role of biosensors in the food and drink industries.

Despite their apparent potential as analytical tools in the food and drink industries, only a few biosensors are used routinely. This article describes the development of biosensors for these sectors and discusses the technical and economic problems of applying this technology to the monitoring of food and drink products.     

Development of a piezoelectric immunosensor for the detection of Salmonella typhimurium.

A piezoelectric biosensor has been developed for the detection of Salmonella typhimurium. The antibody to Salmonella was immobilized on the crystal by various immobilization procedures. The best result was obtained when antibody was immobilized on the crystal precoated with a thin layer of polyethyleneimine. The response of the coated crystal for S. typhimurium in a microbial suspension was in the range of 10(5) to 10(9) cells ml-1. The time required for a complete interaction between the crystal and the cells appeared to depend upon the cell concentration of the analyzed sample. The antibody-bound crystal lost no activity over 4 days at 4 degrees C and it could be reused for 6-8 consecutive assays.     

Local grassland restoration affects insect communities

1. It is hypothesised that ecological restoration in grasslands can induce an alternative stable state shift in vegetation. The change in vegetation influences insect community assemblages and allows for greater functional redundancy in pollination and refuge for native insect species. 2. Insect community assemblages at eight coastal California grassland sites were evaluated. Half of these sites had undergone restoration through active revegetation of native grassland flora and half were non‐restored. Insects were collected from Lupinus bicolor (Fabaceae) within 2 × 2‐m² plots in spring 2017. Lupinus bicolor is a common native species that is used in California restoration projects, and home and state landscaping projects. 3. Ordination demonstrated that insect community assemblages were different between restored and non‐restored sites. These differences were seen in insect functional groups as well as taxa‐specific differences and were found to be driven by environmental characteristics such as non‐native forb cover. 4. Functional redundancy of herbivores decreased at restored sites, while pollinators became more redundant compared with non‐restored sites. The assemblages of the common species found at restoration sites contained more native insects than those found at non‐restored sites, including species such as Bombus vosnesenskii. 5. Local grassland restoration has the potential to induce an alternative stable state change and affect insect community assemblages. Additionally, it was found that grassland restoration can be a potential conservation tool to provide refugia for bumblebees (Bombus), but additional studies are required to fully understand its broader applicability.     

Mutational Analysis of Substrate Inhibition in Tyrosine Hydroxylase

Abstract: Substrate inhibition in tyrosine hydroxylase (TH) was analyzed by deletion mutagenesis. The deletion mutant TH 156/456 was the smallest section of TH to retain substrate inhibition. The TH 156/456 was monomeric, and so multimer formation does not play a role in substrate inhibition in TH. Further deletion at the N terminus to residue 169 produced a TH molecule with no substrate inhibition but high activity. A mutagenic scan of this region showed that mutations at Trp¹⁶⁶ were responsible for this phenotype. A screen of a library of TH molecules containing random mutations identified three other mutants that had lost substrate inhibition but retained high activity. The results in this report are consistent with a model in which substrate inhibition acts through an allosteric mechanism.     

An improved ELISA method for the detection of Salmonella typhimurium

The applicability of enzyme-linked immunosorbent assay (ELISA) for the detection of salmonellas in foodstuffs was investigated. Several factors affecting the sensitivity of the ELISA, such as the type of protein used for plate post-coating, the method of antibody labelling, and accelerators for antigen-antibody and enzyme-substrate reactions, were studied. Labelling of the antibody with horseradish peroxidase and the use of o -phenylenediamine as substrate in the detection system were demonstrated to be most suitable for the enzyme assay.
Based on these findings, an improved ELISA method was developed for the detection of Salmonella typhimurium. The improved technique was able to detect as few as 5×10⁴-10⁵ cell/ml of salmonellas, and about 24 h were required to enrich the bacteria in food samples and to perform the test. With some modifications, the ELISA assay could reach a very high level of sensitivity and provide excellent repro-ducibility.     

Physical Activity in Vietnam: Estimates and Measurement Issues

IntroductionOur aims were to provide the first national estimates of physical activity (PA) for Vietnam, and to investigate issues affecting their accuracy.MethodsMeasurements were made using the Global Physical Activity Questionnaire (GPAQ) on a nationally-representative sample of 14706 participants (46.5% males, response 64.1%) aged 25−64 years selected by multi-stage stratified cluster sampling.ResultsApproximately 20% of Vietnamese people had no measureable PA during a typical week, but 72.9% (men) and 69.1% (women) met WHO recommendations for PA by adults for their age. On average, 52.0 (men) and 28.0 (women) Metabolic Equivalent Task (MET)-hours/week (largely from work activities) were reported. Work and total PA were higher in rural areas and varied by season. Less than 2% of respondents provided incomplete information, but an additional one-in-six provided unrealistically high values of PA. Those responsible for reporting errors included persons from rural areas and all those with unstable work patterns. Box-Cox transformation (with an appropriate constant added) was the most successful method of reducing the influence of large values, but energy-scaled values were most strongly associated with pathophysiological outcomes.ConclusionsAround seven-in-ten Vietnamese people aged 25–64 years met WHO recommendations for total PA, which was mainly from work activities and higher in rural areas. Nearly all respondents were able to report their activity using the GPAQ, but with some exaggerated values and seasonal variation in reporting. Data transformation provided plausible summary values, but energy-scaling fared best in association analyses.     

A Novel Role of Matrix Metalloproteinase-8 in Macrophage Differentiation and Polarization

Matrix metalloproteinase-8 (MMP8) has been shown to influence various cellular functions. As monocytes and macrophages (Mφ) express MMP8, we investigated if MMP8 played a role in macrophage differentiation and polarization. MMP8 expression was significantly increased during monocyte differentiation into Mφ. Monocyte-derived Mφ from MMP8-deficient mice expressed higher levels of M1-Mφ markers but lower levels of M2-Mφ markers than monocyte-derived Mφ from wild-type mice. Although Mφ from either MMP8-deficient or wild-type mice were inducible by interferon-γ into M1-Mφ, only wild-type Mφ but not MMP8-deficient Mφ could be induced into M2-Mφ by interleukin-4. However, MMP8-deficient Mφ exposed to conditioned culture media of wild-type Mφ developed a M2-Mφ phenotype. Compared with conditioned culture media of wild-type Mφ, conditioned culture media of MMP8-deficient Mφ contained a lower concentration of active transforming growth factor-β (TGF-β), an M2-Mφ inducer. Moreover, evidence also showed that the degradation of the TGF-β sequester, fibromodulin, was modulated by MMP8. The data indicate a previously unknown role of MMP8 in M2-Mφ polarization by cleaving fibromodulin and therefore increasing the bioavailability of the M2-Mφ inducer TGF-β.     

Reproduction and initial development of manybar goatfish <Emphasis Type="Italic">Parupeneus multifasciatus</Emphasis> (Mullidae)

Features of reproductive biology and the stages of early ontogeny are described in the mass tropical species manybar goatfish Parupeneus multifasciatus. In general, in the catches represented by mainly sexually mature fishes, females prevail but males prevail in the largest size classes. The females reach their first sexual maturity by approximately 110 mm fork length, and they are characterized by continuous oogenesis and egg deposition in batches. The fish spawn over the entire year with a trend to lower values of the gonadosomatic index (GSI) of the females from June to October. The features of early ontogeny are compared in manybar goatfish and red mullet Mullus barbatus ponticus from the Black Sea.