Strained fermented milks – A review of existing legislative provisions,survey of nutritional labelling of commercial products in selected markets and terminology of products in some selected countries

A survey of the information contained in the labels of 109 commercial concentrated fermented milks from the Eastern Mediterranean, Australasia, the United Kingdom, Ireland, the United States of America and Canada plus Skyr (from Iceland), Ymer (from Denmark) and Chakka (from India) was carried out in late 2012 and early 2013. There were substantial differences in composition. The carbohydrate, fat and protein contents ranged between 1–12, 0–20 and 3.3–11 g/100 g, respectively. Considering the compositional data of the product and existing legislative provisions, a typical strained product should have a protein content of ≥8 g/100 and ~5 g/100 g of carbohydrates, and it would be appropriate to name such products as ‘strained yoghurt’, ‘Greek strained yoghurt’ and/or ‘Labneh’. A higher content of carbohydrate would suggest that the product was made using the product formulation method (i.e. without straining the fermentate), or the milk base had been fortified with skimmed milk before straining the fermentate to enhance the yield of the product, and such products should be known, for example, as ‘Greek‐style yoghurt’. It was also observed in some of the samples that the nomenclature of the starter cultures did not conform to recommendations of the International Union of Microbiological Societies (IUMS). Manufacturers could address such issues to minimise consumer confusion.     

Optimization of single and mixed cultures for solid state fermentation of municipal sewage sludge

Trichoderma harzianum (Th), Phanerochaete chrysosporium ATCC 24725 (Pc) and Mucor hiemalis (Mh) isolated from three sources: wastewater; sewage sludge; and sludge cake were selected for use as compatible/incompatible single and mixed cultures in the treatment of municipal sewage sludge. Five experiments were carried out using (Pc), (Th), a mixture of (Pc/Th), (Mh) and a mixture of (Pc/Mh), in addition to a control where no micro‐organism was used. The experiments were used to evaluate their potential performance as compatible/incompatible single and mixed cultures for the treatment of municipal wastewater sewage sludge from treatment plants using solid state fermentation technique (SSF). The results showed that the best micro‐organism for composting was found to be (Th) and a mixture of (Pc/Th), while (Pc/Mh) was incompatible culture. The C/N ratio for Th changed from 8.46 to 17.8 at the end of the process, (Ph/Th) increased from 7.21 to 15.9, while (Pc/Mh) increased from 8.49 to 29. The pH value also affected by the fungal cultures which was also changed for (Th) from 4.29 to 6.8, for (Pc/Th) was changed from 7.27 to 6.7 and for (Pc/Mh) was changed from 6.6 to 5.3. Effective results were observed by using mixed culture after 19–21 days compared to other single treatments after 24–32 days.     

Metabolic versatility in full-scale wastewater treatment plants performing enhanced biological phosphorus removal

This study analysed the enhanced biological phosphorus removal (EBPR) microbial community and metabolic performance of five full-scale EBPR systems by using fluorescence in situ hybridisation combined with off-line batch tests fed with acetate under anaerobic–aerobic conditions. The phosphorus accumulating organisms (PAOs) in all systems were stable and showed little variability between each plant, while glycogen accumulating organisms (GAOs) were present in two of the plants. The metabolic activity of each sludge showed the frequent involvement of the anaerobic tricarboxylic acid cycle (TCA) in PAO metabolism for the anaerobic generation of reducing equivalents, in addition to the more frequently reported glycolysis pathway. Metabolic variability in the use of the two pathways was also observed, between different systems and in the same system over time. The metabolic dynamics was linked to the availability of glycogen, where a higher utilisation of the glycolysis pathway was observed in the two systems employing side-stream hydrolysis, and the TCA cycle was more active in the A²O systems. Full-scale plants that showed higher glycolysis activity also exhibited superior P removal performance, suggesting that promotion of the glycolysis pathway over the TCA cycle could be beneficial towards the optimisation of EBPR systems.     

Long-term impact of anaerobic reaction time on the performance and granular characteristics of granular denitrifying biological phosphorus removal systems

Removal of nitrogen and phosphorus (P) from wastewater is successfully and widely practiced in systems employing both granular sludge technology and enhanced biological P removal (EBPR) processes; however, the key parameter, anaerobic reaction time (AnRT), has not been thoroughly investigated. Successful EBPR is highly dependent on an appropriate AnRT, which induces carbon and polyphosphate metabolism by phosphorus accumulating organisms (PAOs). Therefore, the long-term impact of AnRT on denitrifying P removal performance and granular characteristics was investigated in three identical granular sludge sequencing batch reactors with AnRTs of 90 (R1), 120 (R2) and 150 min (R3). The microbial community structures and anaerobic stoichiometric parameters related to various AnRTs were monitored over time. Free nitrite acid (FNA) accumulation (e.g., 0.0008–0.0016 mg HNO₂–N/L) occurred frequently owing to incomplete denitrification in the adaptation period, especially in R3, which influenced the anaerobic/anoxic intracellular intermediate metabolites and activities of intracellular enzymes negatively, resulting in lower levels of poly-P and reduced activity of polyphosphate kinase. As a result, the Accumulibacter-PAOs population decreased from 51 ± 2.5% to 43 ± 2.1% when AnRT was extended from 90 to 150 min, leading to decreased denitrifying P removal performance. Additionally, frequent exposure of microorganisms to the FNA accumulation and anaerobic endogenous conditions in excess AnRT cases (e.g., 150 min) stimulated increased extracellular polymeric substances (EPS) production by microorganisms, resulting in enhanced granular formation and larger granules (size of 0.6–1.2 mm), but decreasing anaerobic PHA synthesis and glycogen hydrolysis. Phosphorus removal capacity was mediated to some extent by EPS adsorption in granular sludge systems that possessed more EPS, longer AnRT and relatively higher GAOs.     

Detection of cauliflower mosaic virus by the polymerase chain reaction: testing of food components for false-positive 35S-promoter screening results

 Today DNA-based techniques are very common for the detection of genetically modified organisms (GMOs) in food products. For fast and easy detection of GMOs, polymerase chain reaction (PCR) screening methods, which amplify common transgenic elements, are applied in routine analysis. These techniques do not allow differentiation between GMOs and the natural occurrence of transgenic elements, such as the 35S-promoter of cauliflower mosaic virus (CaMV) or the NOS-terminator of Agrobacterium tumefaciens, and thus may result in false-positive detection of GMOs. In this study we evaluated three different existing 35S screening systems and report the development of two new CaMV-specific PCR systems. These PCR systems based on CaMV-specific genes allow the identification of positively screened 35S food samples as naturally virus-infected products or plants. Seven food samples tested positive in routine 35S screening analysis and negative in GMO specific systems were investigated using the new virus-specific PCR systems. In all seven samples CaMV was detected. Received: 26 April 1999 / Revised version: 28 June 1999     

鱼源特定腐败菌及其应用研究进展

特定腐败菌(specific spoilage organisms,SSOs)是影响鱼肉腐败的重要因素之一。不同条件下鱼源SSOs不同,本文重点就SSOs的确定,即鱼源优势腐败菌筛选及其腐败能力分析的研究现状进行概述。在此基础上,对鱼源SSOs生长预测,靶向控制以延长鱼类鲜品货架期等应用研究进行了总结,旨在说明鱼源SSOs的研究价值,并对SSOs未来研究方向进行了展望。     

The effect of pH on the competition between polyphosphate-accumulating organisms and glycogen-accumulating organisms

In enhanced biological phosphorus removal (EBPR) processes, glycogen-accumulating organisms (GAOs) may compete with polyphosphate-accumulating organisms (PAOs) for the often-limited carbon substrates, potentially resulting in disturbances to phosphorus removal. A detailed investigation of the effect of pH on the competition between PAOs and GAOs is reported in this study. The results show that a high external pH ( approximately 8) provided PAOs with an advantage over GAOs in EBPR systems. The phosphorus removal performance improved due to a population shift favouring PAOs over GAOs, which was shown through both chemical and microbiological methods. Two lab-scale reactors fed with propionate as the carbon source were subjected to an increase in pH from 7 to 8. The phosphorus removal and PAO population (as measured by quantitative fluorescence in situ hybridisation analysis of "Candidatus Accumulibacter phosphatis") increased in each system, where the PAOs appeared to out-compete a group of Alphaproteobacteria GAOs. A considerable improvement in the P removal was also observed in an acetate fed reactor, where the GAO population (primarily "Candidatus Competibacter phosphatis") decreased substantially after a similar increase in the pH. The results from this study suggest that pH could be used as a control parameter to reduce the undesirable proliferation of GAOs and improve phosphorus removal in EBPR systems.     

Irritants and allergens at school in relation to furnishings and cleaning

In order to study the influence of furnishings and cleaning on the indoor air quality at school, 181 randomly chosen classrooms were investigated. The amounts of open shelves, textiles and other fittings were noted, data were gathered on cleaning routines, and a number of pollutants were measured in the classrooms. In classrooms with more fabrics there was more settled dust and the concentration of formaldehyde was higher. Classrooms with more open shelves had more formaldehyde, and more pet allergens in settled dust, and classrooms with a white board, instead of a chalk board, were less dusty. Classrooms mainly cleaned through wet mopping had more airborne viable bacteria but less settled dust than classrooms mainly cleaned by dry methods. In rooms where the desks and curtains were more often cleaned, the concentrations of cat and dog allergen in settled dust were lower. It is concluded that furnishings and textiles in the classroom act as significant reservoirs of irritants and allergens and have an impact on the indoor air quality at school.     

Symbiotic organisms search and two solution representations for solving the capacitated vehicle routing problem

This paper presents the symbiotic organisms search (SOS) heuristic for solving the capacitated vehicle routing problem (CVRP), which is a well-known discrete optimization problem. The objective of CVRP is to decide the routes for a set of vehicles to serve a set of demand points while minimizing the total routing cost. SOS is a simple and powerful metaheuristic that simulates the symbiotic interaction strategies adopted by an organism for surviving in an ecosystem. As SOS is originally developed for solving continuous optimization problems, we therefore apply two solution representations, SR-1 and SR-2, to transform SOS into an applicable solution approach for CVRP and then apply a local search strategy to improve the solution quality of SOS. The original SOS uses three interaction strategies, mutualism, commensalism, and parasitism, to improve a candidate solution. In this improved version, we propose two new interaction strategies, namely competition and amensalism. We develop six versions of SOS for solving CVRP. The first version, SOS_Canonical, utilizes a commonly used continuous to discrete solution representation transformation procedure. The second version is an improvement of canonical SOS with a local search strategy, denoted as SOS_Basic. The third and fourth versions use SR-1 and SR-2 with a local search strategy, denoted as SOS_SR-1 and SOS_SR-2. The fifth and sixth versions, denoted as ISOS_SR-1 and ISOS_SR-2, improve the implementation of SOS_SR-1 and SOS_SR-2 by adding the newly proposed competition and amensalism interaction strategies. The performances of SOS_Canonical, SOS_Basic, SOS_SR-1, and SOS_SR-2 are evaluated on two sets of benchmark problems. First, the results of the four versions of SOS are compared, showing that the preferable result was obtained from SOS_SR-1 and SOS_SR-2. The performances of SOS_SR-1, SOS_SR-2, ISOS_SR-1, and ISOS_SR-2 are then compared, presenting that ISOS_SR-1 and ISOS_SR-2 offer a better performance. Next, the ISOS_SR-1 and ISOS_SR-2 results are compared to the best-known solutions. The results show that ISOS_SR-1 and ISOS_SR-2 produce good VRP solutions under a reasonable computational time, indicating that each of them is a good alternative algorithm for solving the capacitated vehicle routing problem.     

Effects of Hydroxyl Radicals on Introduced Organisms of Ship＇s Ballast Water Based Micro-Gap Discharge

With the physical method of micro-gap gas discharge, OH. radicals were produced by the ionization of O2 in air and H2O in the gaseous state, in order to explore more effective method totreat the ship＇s ballast water. The surface morphology of Al2O3 dielectric layer was analysed using Atomic Force Microscopy （AFM）, where the size of Al2O3 particles was in the range of 2 μm to 5 μm. At the same time, the biochemical effect of hydroxyl radicals on the introduced organisms and the quality of ship＇s ballast water were studied. The results indicate that the main reasons of cell death are lipid peroxide and damage of the antioxidant enzyme system in Catalase （CAT）, Peroxidase （POD） and Superoxide dismutase （SOD）. In addition, the quality of the ballast water was greatly improved.