Polyoxazoline associated with cardanol for bio‐based linear alkyl benzene surfactants

Well‐defined linear alkyl benzene surfactants (COx_n) were successfully synthesized using cardanol as a green phenolic alternative and initiator for polyoxazoline (POx), the hydrophilic block of nonionic surfactants. Various hydrophilic lipophilic balance values were investigated by varying the POx length according to the [monomer]/[initiator] ratio. The chemical structure of the surfactants, in particular the terminal groups, was well identified by matrix assisted laser desorption ionization time of flight mass spectrometry demonstrating the good progress of the cationic ring‐opening polymerization. The COx_n surfactants spontaneously self‐assembled in water at a critical aggregation concentration of 1–2 µmol L^?1 into nano‐objects characterized by a hydrodynamic diameter of 11–24 nm and a number of aggregations ranging from 30 to 60 according to the worm‐like micelle model. © 2019 Society of Chemical Industry     

Degradation of ascorbic acid and potassium sorbate by different Lactobacillus species isolated from packed green olives

The aim of this research was to ascertain the lactic acid bacteria responsible for the degradation of ascorbic acid and/or potassium sorbate, isolated from packed green olives where these additives had diminished. A total of 14 isolates were recovered from samples of different green olive containers. According to partial sequencing of the 16S rRNA coding gene, Lactobacillus parafarraginis, Lactobacillus rapi, Lactobacillus pentosus, Lactobacillus paracollinoides, and Pediococcus ethanolidurans were identified. With the exception of L. pentosus and L. paracollinoides, the other species had not been mentioned in table olives before this study. Only three of the 14 isolates metabolized ascorbic acid in MRS broth, and the products from ascorbic acid in modified MRS broth without carbon sources were acetic and lactic acids. Except for the two L. rapi and the two P. ethanolidurans strains, the remaining 10 isolates depleted potassium sorbate added into MRS broth to some extent. The product generated by three of these strains was confirmed to be trans-4-hexenoic acid. The degradation of ascorbate or sorbate by lactic acid bacteria should be taken into account when these additives are used in food products where this group of bacteria may be present.     

Functionality and safety of lactic bacterial strains from Korean kimchi

The functional characteristics and safety of five different putative probiotic Lactobacillus plantarum strains and one Leuconostoc citreum strain, isolated from kimchi, were studied. In view of their potential application in food biotechnology, this information was considered necessary, and included the determination of antibiotic resistance, haemolysis, gelatinase activity and biogenic amine production. In addition to a Lactobacillus fermentum strain isolated from pig faeces, two commercial probiotic strains (Lactobacillus rhamnosus GG, ATCC 53103, and Lactobacillus plantarum 299v, both originating from the human intestinal track) were included in the studies for reference purposes. With the exception of L. fermentum, which was resistant to a low concentration (MIC: 30 μg/ml) of tetracycline, all strains were susceptible to the 8 antibiotics tested (erythromycin, gentamicin, ampicillin, tetracycline, chloramphenicol, streptomycin, ciprofloxacin, and benzylpenicillin). All strains survived physiological conditions typical of the upper GIT, comprising a pH of 3.0 for 1 h, and a subsequent 2 h under conditions simulating the duodenum, which included the exposure to 10 % of bile salts. Moreover, all strains were resistant to 0.4 % phenol, and were unable to produce any detectable biogenic amines under the test conditions. These preliminary in vitro tests indicate the safety and functionality of the five selected L. plantarum strains and thus their potential as probiotic candidates.     

Lead-acid and lithium-ion batteries for the Chinese electric bike market and implications on future technology advancement

China has been experiencing a rapid increase in battery-powered personal transportation since the late 1990s due to the strong growth of the electric bike and scooter (i.e. e-bike) market. Annual sales in China reached 17 million bikes year⁻¹ in 2006. E-bike growth has been in part due to improvements in rechargeable valve-regulated lead-acid (VRLA) battery technology, the primary battery type for e-bikes. Further improvements in technology and a transition from VRLA to lithium-ion (Li-ion) batteries will impact the future market growth of this transportation mode in China and abroad.     

Use of whey and buttermilk based media to obtain biomass of thermophilic LAB

The growth of commercial strains of thermophilic lactic acid bacteria (LAB) was determined in reconstituted dried whey and buttermilk. Kinetic (μ, /h and g, h) and growth (N, cfu/mL; X, cell yield and I_V , percentual variation) parameters were determined using Elliker (streptococci) and MRS (lactobacilli) broths, and a commercial medium as controls. Cheese whey was the least effective substrate for growing streptococci and lactobacilli strains. However, whey and buttermilk with added yeast extract gave the best performance. These media could be efficient and easily available alternatives for producing industrial biomass of thermophilic LAB.     

Post-Digital Transdisciplinarity

Why are buildings generally credited to a single individual or firm, without acknowledging the numerous other participants in their creation? Marjan Colletti , founder and director of the REX|LAB robotic experimentation laboratory at the University of Innsbruck, reflects on the nature and implications of transdisciplinarity. With reference to REX|LAB's contribution to the highly collaborative 2015 show of Iris van Herpen's Quaquaversal ready-to-wear collection, he further considers the increasingly understated approach to technological presence in the post-digital age.     

一种基于LAB色空间拓扑剖分影射的颜色恒常性模型

 本文针对人体肤色和黏膜颜色特点,建立一种室内自然光条件下的医学真彩图像采集分析的颜色恒常性模型.在LAB均匀色度空间中,对一维L*空间进行线性影射,二维a*b*空间进行三角剖分影射和还原,建立了一种拓扑剖分影射TRM模型.通过对SG色标中13个肤色色标进行的校正还原,结果显示,TRM模型还原的颜色色差明显减小,离散度小,性能稳定.     

Molecular and physiological characterization of natural microbial communities isolated from a traditional Southern Italian processed sausage

The development of the natural microbial populations during traditional processing of the "Salame di Senise", a typical little known sausage produced in the South of Italy, was investigated by using molecular and physiological techniques for taxonomic identification and technological characterization of strains. The application of RAPD-PCR over more than 90 colonies made it possible to isolate 18 bacterial and two yeast biotypes identified by partial rDNA sequencing as belonging mainly to three species of Bacillus, three species of Lactobacillus, three species of Staphylococcus and Debaryomyces hansenii. The physiological analyses revealed that the isolates belonging to Lactobacillus genus were the most acidifying, whereas Staphylococcus strains did not develop significant proteolytic and lipolytic activities. Interestingly, some Bacillus strains produced the highest values of proteolytic and lipolytic activities. The results for the technological properties of Bacillus strains isolated from this Southern Italian sausage, made without a selected starter, suggest that Bacillus strains, always present in meat curing, could play a role in the development of texture and organoleptic characteristics of the sausages.     

Bacteriocins: Recent Trends and Potential Applications

In the modern era, there is great need for food preservation in both developing and developed countries due to increasing demand for extending shelf life and prevention of spoilage of food material. With the emergence of new pathogens and ability of micro-organisms to undergo changes, exploration of new avenues for the food preservation has gained importance. Moreover, awareness among consumers regarding harmful effects of chemical preservatives has been increased. Globally, altogether there is increasing demand by consumers for chemical-free and minimal processed food products. Potential of bacteriocin and its application in reducing the microbiological spoilages and in the preservation of food is long been recognized. Bacteriocins are normally specific to closely related species without disrupting the growth of other microbial populations. A number of applications of bacteriocin have been reported for humans, live stock, aquaculture etc. This review is focused on recent trends and applications of bacteriocins in different areas in addition to their biopreservative potential.     

Probiotic spectra of lactic acid bacteria (LAB)

Lactic acid bacteria (LAB) and their probio-active cellular substances exert many beneficial effects in the gastrointestinal tract. LAB prevent adherence, establishment, and replication of several enteric mucosal pathogens through several antimicrobial mechanisms. LAB also release various enzymes into the intestinal lumen and exert potential synergistic effects on digestion and alleviate symptoms of intestinal malabsoption. Consumption of LAB fermented dairy products with LAB may elicit antitumor effects. These effects are attributed to the inhibition of mutagenic activity; decrease in several enzymes implicated in the generation of carcinogens, mutagens, or tumor-promoting agents; suppression of tumors; and the epidemiology correlating dietary regimes and cancer. Specific cellular components in LAB strains seem to induce strong adjuvant effects including modulation of cell-mediated immune responses, activation of reticuloendothelial system, augmentation of cytokine pathways and regulation of interleukins, and tumor necrosis factors. Oral administration of LAB is well tolerated and proven to be safe in 143 human clinical trials and no adverse effects were reported in any of the total 7,526 subjects studied during 1961-1998. In an effort to decrease the reliance on synthetic antimicrobials and control the emerging immunocompromised host population, the time has come to carefully explore the prophylactic and therapeutic applications of probiotic LAB.