Fidget spinners, which are toys used by children of school age, became very popular in 2017. During normal use, they are in direct and prolonged contact with the skin on the hands. Fidget spinners may have metals parts, and therefore represent a potential source of metal contact allergy and thus allergic contact dermatitis. The aim of this study was to screen a random selection of fidget spinners on the Danish market for nickel and cobalt release.

The economic feasibility of biochemical conversion of wheat straw to butyric acid was studied in this work. Basic process steps included physicochemical pretreatment, enzymatic hydrolysis and saccharification, fermentation with in-situ acids separation by electrodialysis and product purification. Two scenarios (S1 and S2) were examined assuming a plant with an annual capacity of 10,000tonnes of product installed in India (due to significantly lower feedstock prices). S1 resulted in a product of 89% butyric acid mixed with acetic acid and S2 produced butyric acid of 99% purity. Unit production cost was estimated at 2.75 and 3.31 $ per kg product for S1 and S2 respectively. The main part of production cost was attributed to steam for the purification step and electricity for the in-situ acids separation. This unit production cost combined with an estimated butyric acid selling price (year 2014) at 3.50 and 3.95 $ per kg product (for S1 and S2 respectively) and a plant capacity of 10,000tonnes indicated an internal rate of return of 14.92% and 12.42% and payback time of 4.28 and 4.70 years for S1 and S2 respectively. Sensitivity analysis showed that under the assumptions of the present study the optimum plant capacity would lie between 10,000 and 15,000tonnes of product per year.

Background: Whole grains have shown potential for improving gut health, but evidence comparing different whole-grain types is lacking.Objective: We investigated whether whole-grain wheat (WGW) and whole-grain rye (WGR) improve gut health in different ways compared to refined wheat (RW), with the primary outcomes of microbiota composition and gastrointestinal (GI) symptoms.Methods: In a randomized parallel trial, 70 healthy adults (in means ± SDs; aged 51.0 ± 9.4 y, body mass index [BMI (in kg/m2)] 27.8 ± 1.9, 32:38 men:women) replaced cereal foods from their habitual diet with WGR, WGW, or RW (control). Before and after a 6-wk intervention, a spot stool sample was collected and analyzed for short-chain fatty acids and microbiota composition through the use of 16S ribosomal RNA gene-targeted high-throughput amplicon sequencing. GI symptoms and stool regularity were evaluated by questionnaires at baseline and after weeks 2, 4, and 6.Results: Intakes of whole grains were 145.2 ± 75.9, 124.2 ± 57.3, and 5.4 ± 3.2 g/d in the WGW, WGR, and RW groups, respectively. Gut microbiota composition was not affected by diet. The relative change in fecal butyrate decreased in the RW (-38%) group compared to the WGW (25%, P = 0.014) and WGR groups (-1%, P = 0.037). Other short-chain fatty acids were unaffected. Flatulence was more frequent following intake of WGW (OR: 2.06, 95% CI: 1.03, 4.17) and WGR (OR: 2.62, 95% CI: 1.35, 5.22) compared to RW, whereas bloating was less frequent following WGW (OR: 0.38, 95% CI: 0.18, 0.80) and WGR (OR: 0.34, 95% CI: 0.16, 0.72). Stool frequency increased following WGR but not WGW, compared to RW in weeks 2 (0.4 defecations/d, P = 0.049) and 4 (0.5 defecations/d, P = 0.043), but not in week 6. The WGW and WGR groups did not differ from each other in any of the variables tested.Conclusion: Regular consumption of WGR and WGW affected fecal butyrate concentration and gastrointestinal symptoms in healthy overweight adults, supporting the hypothesis that WGR and WGW can be included in the diet equally to maintain gut health. This trial was registered at clinicaltrials.gov as NCT02358122.

Biological production of organic acids from conversion of biomass derivatives has received increased attention among scientists and engineers and in business because of the attractive properties such as renewability, sustainability, degradability, and versatility. The aim of the present review is to summarize recent research and development of short chain fatty acids production by anaerobic fermentation of nonfood biomass and to evaluate the status and outlook for a sustainable industrial production of such biochemicals. Volatile fatty acids (VFAs) such as acetic acid, propionic acid, and butyric acid have many industrial applications and are currently of global economic interest. The focus is mainly on the utilization of pretreated lignocellulosic plant biomass as substrate (the carbohydrate route) and development of the bacteria and processes that lead to a high and economically feasible production of VFA. The current and developing market for VFA is analyzed focusing on production, prices, and forecasts along with a presentation of the biotechnology companies operating in the market for sustainable biochemicals. Finally, perspectives on taking sustainable product of biochemicals from promise to market introduction are reviewed.

The present study focused on fermentative butyric acid production by Clostridium tyrobutyricum from pre-treated and hydrolysed wheat straw (PHWS) based on continuous operation mode and in situ acids extraction by reverse electro enhanced dialysis (REED). Different dilutions of PHWS in a synthetic medium (60-100 % v/v) were tested. It was found that continuous fermentation of PHWS greatly enhanced the sugar consumption rates and butyric acid productivity compared to batch tests, while application of REED enhanced them even further. Specifically, applying combined continuous operation mode and REED system for the fermentation of 70 % PHWS resulted in 19-and 53-fold higher glucose (1.37 g L-1 h(-1)) and xylose (0.80 g L-1 h(-1)) consumption rates, respectively, compared to those obtained by batch processing. Fermentation of 100 % PHWS continued unhindered with just urea and K2HPO4 added with butyric acid production rate, yield and selectivity being 1.30 g L-1 h(-1), 0.45 g g(-1) sugars and 0.88 g g(-1) acids, respectively. These results were also confirmed in a 20 L pilot plant bioreactor system.

Butyric acid is a valuable building-block for the production of chemicals and materials and nowadays it is produced exclusively from petroleum. The aim of this study was to develop a suitable and robust strain of Clostridium tyrobutyricum that produces butyric acid at a high yield and selectivity from lignocellulosic biomasses. Pretreated (by wet explosion) and enzymatically hydrolysed wheat straw (PHWS), rich in C6 and C5 sugars (71.6 and 55.4gl(-1) of glucose and xylose respectively), was used as substrate. After one year of serial selections, an adapted strain of C.tyrobutyricum was developed. The adapted strain was able to grow in 80% (vv(-1)) PHWS without addition of yeast extract compared with an initial tolerance to less than 10% PHWS and was able to ferment both glucose and xylose. It is noticeable that the adapted C.tyrobutyricum strain was characterized by a high yield and selectivity to butyric acid. Specifically, the butyric acid yield at 60-80% PHWS lie between 0.37 and 0.46gg(-1) of sugar, while the selectivity for butyric acid was as high as 0.9-1.0gg(-1) of acid. Moreover, the strain exhibited a robust response in regards to growth and product profile at pH 6 and 7.

In the present study, the effect of potassium ions and increasing concentrations of glucose and xylose on the growth of a strain of Clostridium tyrobutyricum, adapted to wheat straw hydrolysate, was investigated. Application of continuous fermentation of a mixture of glucose and xylose and in situ acid removal by reverse electro enhanced dialysis (REED) was investigated as a method to alleviate potassium and end-product inhibition and consequently enhance the sugar consumption rates and butyric acid productivity. It was found that glucose and xylose were not inhibitory up to a concentration of 50 and 37 g L−1 respectively, and that they were consumed at comparable rates when fermented alone. However, continuous fermentation of a mixture of glucose and xylose resulted in a significantly decreased xylose consumption rate compared to that of glucose alone, supporting the conclusion that C. tyrobutyricum has a lower affinity for xylose than for glucose. Potassium ions negatively affected the effective maximum growth rate of C. tyrobutyricum at concentrations higher than 5 g L−1 exhibiting a non-competitive type of inhibition. Continuous fermentation of a glucose and xylose mixture with simultaneous acid removal by REED resulted in a two to threefold increase of the glucose consumption rate, while the xylose consumption rate was enhanced sixfold compared to continuous fermentation without in situ acid removal. Similarly, butyric acid productivity was enhanced by a factor of 2–3, while the yield remained unaffected.

The increasing demand for energy and the related environmental concerns are the main drivers for the strong interest in Biomass Fermentation towards usage in Fuel Cells. The integration of Biomass Fermentation (BF) and Fuel Cells (FC) technology creates a new and interdisciplinary research area.Due to their high efficiency Fuel Cells are therefore considered as a strategic technology for future energy supply systems. The fact that biomass is a renewable source of energy in combination with the most efficient energy conversion system (FC) makes this combination unique and advantageous.This book has a clear orientation towards making products of our waste. Biofuels for Fuel Cells comes at a time when this field is rapidly developing and there is a need for a synthetising book. The holistic and multidisciplinary description of this topic, including discussion of technological, socio-economic, system analysis and policy and regulatory aspects, make this book the definitive work for this market.Biofuels for Fuel Cells will cross-link scientists of all fields concerned with Biomass Fermentation, Fuel Upgrading and Fuel Cells at European and World level.This title belongs to Integrated Environmental Technology SeriesISBN: 9781843390923 (Print)ISBN: 9781780403021 (eBook)

One barrier to cross during genetic engineering is the restriction‐modification system found in many bacteria. In this study, we developed a fast and reliable method for mapping the recognition and cleavage site of the restriction endonucleases. Clostridium pasteurianum, a model organism for the study of nitrogen fixation, has been found to harbour at least two restriction‐modification systems including the restriction endonucleases CpaPI, which is an isoschizomer of MboI and CpaAI. Dam‐methylated DNA was used to isolate the activity of CpaAI. Exposing freshly prepared cell lysate to known nucleotide fragments and directly sequencing the pool of digested nucleotide fragments enabled identification of the cleavage sites in the fragments. By aligning the sequences adjacent to the cleavage site, it was possible to identify the recognition sequence. Using this method, we successfully located all CpaAI recognition and cleavage sites within the template sequence. By modifying DNA with both Dam and CpG methylases (M.SssI) and thereby preventing digestion by CpaPI and CpaAI, no further endonuclease activity was detected.