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Utilization of renewable and low-cost lignocellulosic wastes has received major focus in industrial lactic acid production. The use of high solid loadings in biomass pretreatment potentially offers advantages over low solid loadings including higher lactic acid concentration with decreased production and capital costs. In this study, an isolated Enterococcus faecalis SI with optimal temperature 42 °C was used to produce optically pure L-lactic acid (> 99%) from enzyme-saccharified hydrolysates of acid-impregnated steam explosion (AISE)-treated plywood chips. The L-lactic acid production increased by 10% at 5 L scale compared to the similar fermentation scheme reported by Wee et al. The fermentation with a high solid loading of 20% and 35% (w/v) AISE-pretreated plywood chips had been successfully scaled up to process development unit scale (100 L) and pilot scale (9 m), respectively. This is the first report of pilot-scale lignocellulosic lactic acid fermentation by E. faecalis with high lactic acid titer (nearly 92 g L) and yield (0.97 kg kg). Therefore, large-scale L-lactic acid production by E. faecalis SI shows the potential application for industries.

The aim of this study was to develop a method to optimize expression levels of xylose-metabolizing enzymes to improve xylose utilization capacity of Saccharomyces cerevisiae. A xylose-utilizing recombinant S. cerevisiae strain YY2KL, able to express nicotinamide adenine dinucleotide phosphate, reduced (NADPH)-dependent xylose reductase (XR), nicotinamide adenine dinucleotide (NAD(+))-dependent xylitol dehydrogenase (XDH), and xylulokinase (XK), showed a low ethanol yield and sugar consumption rate. To optimize xylose utilization by YY2KL, a recombinant expression plasmid containing the XR gene was transformed and integrated into the aur1 site of YY2KL. Two recombinant expression plasmids containing an nicotinamide adenine dinucleotide phosphate (NADP(+))-dependent XDH mutant and XK genes were dually transformed and integrated into the 5S ribosomal DNA (rDNA) sites of YY2KL. This procedure allowed systematic construction of an S. cerevisiae library with different ratios of genes for xylose-metabolizing enzymes, and well-grown colonies with different xylose fermentation capacities could be further selected in yeast protein extract (YPX) medium (1 % yeast extract, 2 % peptone, and 2 % xylose). We successfully isolated a recombinant strain with a superior xylose fermentation capacity and designated it as strain YY5A. The xylose consumption rate for strain YY5A was estimated to be 2.32 g/gDCW/h (g xylose/g dry cell weight/h), which was 2.34 times higher than that for the parent strain YY2KL (0.99 g/gDCW/h). The ethanol yield was also enhanced 1.83 times by this novel method. Optimal ratio and expression levels of xylose-metabolizing enzymes are important for efficient conversion of xylose to ethanol. This study provides a novel method that allows rapid and effective selection of ratio-optimized xylose-utilizing yeast strains. This method may be applicable to other multienzyme systems in yeast.

Introduction The diagnosis of adult-onset Still’s disease (AOSD) is often delayed due to its clinical heterogeneity and lack of pathognomic features. Hence, there is an unmet need for an efficient diagnostic process. The major aim of this study was to compare the differences in disease outcomes between two groups of AOSD patients with and without implementation of the streamlined diagnostic process (SDP). Methods Of 172 febrile patients with skin rash and/or arthralgia, 112 individuals had AOSD. The tentative diagnosis of AOSD or non-AOSD was made with or without the SDP implementation. The selection criteria for AOSD outcomes analysis were as follows: (1) age at study entry older than 20 years, (2) fulfillment of the Yamaguchi criteria for AOSD diagnosis, and (3) a follow-up period longer than 6 months after initiation of therapy. Three outcome parameters were evaluated, including diagnosis lag period, the proportion of “early diagnosis,” and the proportion of achieving disease remission after a 6-month therapy. Results The SDP was implemented for expediting AOSD diagnosis in 41 (36%) enrolled patients (SDP-implemented group). The diagnosis lag period was significantly shorter in the SDP-implemented group (median 2.0 weeks, interquartile range [IQR] 1.0–2.5 weeks) than in the non-SDP-implemented group (4.0 weeks, IQR 2.0–6.0 weeks, p < 0.001). A significantly higher proportion of “early diagnosis” was also found in the SDP-implemented group (75.6%) compared with the non-SDP-implemented group (33.8%, p < 0.001). We revealed a significantly higher proportion of achieving remission in the SDP-implemented group (85.4%) compared with the non-SDP-implemented group (67.6%, p < 0.05). Logistic regression analysis revealed SDP implementation as a potential predictor of achieving disease remission. Conclusions Implementing an SDP for expediting diagnosis could improve outcomes for AOSD patients. This diagnostic process increased the early diagnosis rate and led to a higher disease remission rate. However, the beneficial effects of SDP implementation need further external validation.