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1.
Free lactic acid production under acidic conditions by lactic acid bacteria strains: challenges and future prospects.
Singhvi, M, Zendo, T, Sonomoto, K
Applied microbiology and biotechnology. 2018;(14):5911-5924
Abstract
Lactic acid (LA) is an important platform chemical due to its significant applications in various fields and its use as a monomer for the production of biodegradable poly(lactic acid) (PLA). Free LA production is required to get rid of CaSO4, a waste material produced during fermentation at neutral pH which will lead to easy purification of LA required for the production of biodegradable PLA. Additionally, there is no need to use corrosive acids to release free LA from the calcium lactate produced during neutral fermentation. To date, several attempts have been made to improve the acid tolerance of lactic acid bacteria (LAB) by using both genome-shuffling approaches and rational design based on known mechanisms of LA tolerance and gene deletion in yeast strains. However, the lack of knowledge and the complexity of acid-tolerance mechanisms have made it challenging to generate LA-tolerant strains by simply modifying few target genes. Currently, adaptive evolution has proven an efficient strategy to improve the LA tolerance of individual/engineered strains. The main objectives of this article are to summarize the conventional biotechnological LA fermentation processes to date, assess their overall economic and environmental cost, and to introduce modern LA fermentation strategies for free LA production. In this review, we provide a broad overview of free LA fermentation processes using robust LAB that can ferment in acidic environments, the obstacles to these processes and their possible solutions, and the impact on future development of free LA fermentation processes commercially.
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2.
Recent advancements in lactic acid production - a review.
Eş, I, Mousavi Khaneghah, A, Barba, FJ, Saraiva, JA, Sant'Ana, AS, Hashemi, SMB
Food research international (Ottawa, Ont.). 2018;:763-770
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3.
Longer-Period Effects of Bicarbonate/Lactate-Buffered Neutral Peritoneal Dialysis Fluid in Patients Undergoing Peritoneal Dialysis.
Hoshino, T, Kaneko, S, Minato, S, Yanai, K, Mutsuyoshi, Y, Ishii, H, Kitano, T, Shindo, M, Miyazawa, H, Aomatsu, A, et al
Therapeutic apheresis and dialysis : official peer-reviewed journal of the International Society for Apheresis, the Japanese Society for Apheresis, the Japanese Society for Dialysis Therapy. 2018;(6):641-648
Abstract
High concentrations of lactate are considered to contribute to impairment of the peritoneal membrane. We investigated the longer-period effects of bicarbonate/lactate-buffered neutral peritoneal dialysis fluid (PDF) in patients undergoing PD for about 2 years. Patients undergoing PD were changed from a lactate-buffered neutral PDF to a bicarbonate/lactate-buffered neutral PDF. We then investigated the patients' clinical outcomes and peritoneal membrane functions as well as the surrogate markers in the drained dialysate. Fourteen patients undergoing PD were enrolled. Peritonitis was observed in one patient. No other adverse events were observed. Peritoneal function did not change as the ultrafiltration volume decreased. Fibrin degradation products and vascular endothelial growth factor in the drained dialysate decreased while the interleukin level increased. These results suggest that bicarbonate/lactate-buffered neutral PDF may have beneficial effects in terms of peritoneal preservation and can be safely used in patients undergoing PD.
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4.
Concomitant monitoring of implant formation and drug release of in situ forming poly (lactide-co-glycolide acid) implants in a hydrogel matrix mimicking the subcutis using UV-vis imaging.
Sun, Y, Jensen, H, Petersen, NJ, Larsen, SW, Østergaard, J
Journal of pharmaceutical and biomedical analysis. 2018;:95-106
Abstract
For poly (lactide-co-glycolide acid) (PLGA)-based in situ forming implants, the rate of implant formation plays an important role in determining the overall drug release kinetics. Currently, in vitro techniques capable of characterizing the processes of drug release and implant formation at the same time are not available. A hydrogel-based in vitro experimental setup was recently developed requiring only microliter of formulation and forming a closed system potentially suitable for interfacing with various spectroscopic techniques. The aim of the present proof-of-concept study was to investigate the feasibility of concomitant UV imaging, Vis imaging and light microscopy for detailed characterization of the behavior of in situ forming PLGA implants in the hydrogel matrix mimicking the subcutis. The model compounds, piroxicam and α-lactalbumin were added to PLGA-1-methyl-2-pyrrolidinone and PLGA-triacetin solutions. Upon bringing the PLGA-solvent-compound pre-formulation in contact with the hydrogel, Vis imaging and light microscopy were applied to visualize the depot formation and UV imaging was used to quantify drug transport in the hydrogel. As compared to piroxicam, the α-lactalbumin invoked an acceleration of phase separation and an increase of implant size. α-Lactalbumin was released faster from the PLGA-1-methyl-2-pyrrolidinone system than the PLGA-triacetin system opposite to the piroxicam release pattern. A linear relationship between the rate of implant formation and initial compound release within the first 4h was established for the PLGA-NMP systems. This implies that phase separation may be one of the controlling factors in drug release. The rate of implant formation may be an important parameter for predicting and tailoring drug release. The approach combining UV imaging, Vis imaging and light microscopy may facilitate understanding of release processes and holds potential for becoming a useful tool in formulation development of in situ forming implants.
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5.
Can Caffeine Intake Improve Neuromuscular and Technical-Tactical Performance During Judo Matches?
Athayde, MSDS, Lima Kons, R, Detanico, D
Journal of strength and conditioning research. 2018;(11):3095-3102
Abstract
Athayde, MSdS, Lima Kons, R, and Detanico, D. Can caffeine intake improve neuromuscular and technical-tactical performance during judo matches? J Strength Cond Res 32(11): 3095-3102, 2018-This study aimed to verify the effect of caffeine intake on blood lactate concentrations and neuromuscular and technical-tactical performance during simulated judo matches. Fourteen male judo athletes received capsules containing caffeine or placebo and were evaluated in both conditions. Before the baseline and 1 hour after the caffeine/placebo intake, athletes performed the countermovement jump (CMJ) test, handgrip strength, judogi grip strength test (JGST), and blood samples were collected. Subsequently, the athletes were submitted to three 5-minute matches with 15-minute intervals. All neuromuscular tests were performed and blood samples were taken during the matches' intervals. Significant interaction between condition and time (p = 0.01) was found for blood lactate concentrations. No interaction between condition and time was verified for CMJ performance (p > 0.05), handgrip strength (p > 0.05), JGST performance (p = 0.32), and number of attacks (p = 0.97). However, for all variables, a significant decrease was observed throughout time (p ≤ 0.05). According to clinical results (magnitude-based inference), we identified that post-match 2 and post-match 3 showed higher effect (most likely positive effect) regarding delta caffeine-placebo than other moments (pre-match and post-match 1) for blood lactate. Caffeine increased the estimated glycolytic contribution over the matches; however, it did not induce improvements in neuromuscular performance or number of attacks.
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6.
Increasing effort without noticing: A randomized controlled pilot study about the ergogenic placebo effect in endurance athletes and the role of supplement salience.
Broelz, EK, Wolf, S, Schneeweiss, P, Niess, AM, Enck, P, Weimer, K
PloS one. 2018;(6):e0198388
Abstract
PURPOSE Previous research shows that endurance performance can be enhanced by placebo ergogenic aids. This study investigates the ergogenic placebo response, which we define as an increase in objective and physiological effort without an increase in subjective effort, in competitive cyclists. The primary objective of this study is to explore the role of supplement salience in the ergogenic placebo response, while the secondary aim is to assess whether believing to have taken an inactive placebo supplement attenuates the desired ergogenic effect. METHODS We employed a double-blind placebo-controlled study design and compared a high salience (pudding) to a low salience (capsules) ergogenic placebo supplement and to a no treatment control group. Thirty-four male athletes (30.0 ± 5.7 years) performed two self-regulated time trials on an isokinetic cycling ergometer, one without intervention serving as a baseline and one with intervention according to group assignment. At both time trials, power output (objective effort), blood lactate (physiological effort) and the rating of perceived exertion (subjective effort) were measured. RESULTS Receiving a high salience supplement can increase physiological and objective effort without a proportional rise in subjective effort, suggesting a decoupling of perceived exertion and endurance performance. Low salience and control group both showed no such ergogenic placebo response. Athletes' belief concerning the true nature of the ergogenic aid (inactive placebo vs. ergogenic supplement) did not influence the ergogenic placebo response. CONCLUSION High salience placebo ergogenic aids can elicit enhanced performance without the athlete noticing (exertion), and deception of athletes seems unnecessary as even believing to have received an inactive placebo supplement maintains the ergogenic placebo response.
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7.
The effects of taurine on repeat sprint cycling after low or high cadence exhaustive exercise in females.
Waldron, M, Knight, F, Tallent, J, Patterson, S, Jeffries, O
Amino acids. 2018;(6):663-669
Abstract
This study investigated the effects of taurine on repeated sprint exercise, performed after fixed incremental ramp exercise to exhaustion at isokinetic high (90 r/min) or low (50 r/min) cadences. In a double-blind, repeated measures design, nine females completed an incremental ramp test to volitional exhaustion, followed by 2 min active recovery and 6 × 10 s sprints on a cycle ergometer, in one of four conditions: high cadence (90 r/min) + taurine (50 mg/kg body mass); high cadence + placebo (3 mg/kg body mass maltodextrin); low cadence (50 r/min) + taurine; low cadence + placebo. Heart rate (HR) and blood lactate concentration B[La] were measured before and after the ramp test and after the sprints. Taurine lowered HR vs. placebo prior to the ramp test (P = 0.004; d = 2.1). There was an effect of condition on ramp performance (P < 0.001), with higher end-test power (d = 3.7) in taurine conditions. During repeated sprints, there was a condition × time interaction (P = 0.002), with higher peak sprint power in the placebo conditions compared to taurine (sprint 2-6; P < 0.05). B[La] was higher in taurine compared to placebo post-ramp (P = 0.004; d = 4.7). Taurine-lowered pre-exercise HR and improved incremental end-test power output, with subsequent detrimental effects on sprint performance, independent of cadence. Short endurance performance can be acutely enhanced after taurine ingestion but this effect might not be maintained across longer periods of exercise or induce the need for longer recovery periods.
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8.
Neonatal mitochondrial leukoencephalopathy with brain and spinal involvement and high lactate: expanding the phenotype of ISCA2 gene mutations.
Toldo, I, Nosadini, M, Boscardin, C, Talenti, G, Manara, R, Lamantea, E, Legati, A, Ghezzi, D, Perilongo, G, Sartori, S
Metabolic brain disease. 2018;(3):805-812
Abstract
A homoallelic missense founder mutation of the iron-sulfur cluster assembly 2 (ISCA2) gene has been recently reported in six cases affected by an autosomal recessive infantile neurodegenerative mitochondrial disorder. We documented a case of a 2-month-old girl presenting with severe hypotonia and nystagmus, who rapidly deteriorated and died at the age of three months. Increased cerebral spinal fluid level of lactate, documented also at the brain spectroscopy, involvement of the cortex, restricted diffusion of white and gray matter abnormalities, sparing of the corpus callosum and extensive involvement of the spinal cord were observed. Her clinical presenting features and course as well as some neuroradiological findings mimicked those of early-onset leukoencephalopathy with brainstem and spinal cord involvement and high brain lactate (LBSL). The analysis of the mitochondrial respiratory chain function showed a reduced activity of complexes II and IV. The girl harboured two heterozygous mutations in the ISCA2 gene. A comprehensive review of the literature and a comparison with the cases of early onset LBSL enabled us to highlight significant differences in the clinical, biochemical and neuroradiological phenotype between the two conditions, which also emerged from the comparison with the other 6 reported cases of ISCA2 gene mutation previously reported. In summary, this represents the second report ever published associating ISCA2 gene mutation with a mitochondrial leukoencephalopathy, with a different genetic mechanism to the previous cases. Molecular analysis of ISCA2 should be included in the genetic panel for the diagnosis of early onset mitochondrial leukoencephalopathies.
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9.
Lactic acid fermentation of human excreta for agricultural application.
Andreev, N, Ronteltap, M, Boincean, B, Lens, PNL
Journal of environmental management. 2018;:890-900
Abstract
Studies show that source separated human excreta have a fertilizing potential with benefits to plant growth and crop yield similar or exceeding that of mineral fertilizers. The main challenges in fertilizing with excreta are pathogens, and an increased risk of eutrophication of water bodies in case of runoff. This review shows that lactic acid fermentation of excreta reduces the amount of pathogens, minimizes the nutrient loss and inhibits the production of malodorous compounds, thus increasing its agricultural value. Pathogens (e.g., Enterobacteriacea, Staphylococcus and Clostridium) can be reduced by 7 log CFUg-1 during 7-10 days of fermentation. However, more resistant pathogens (e.g. Ascaris) are not always efficiently removed. Direct application of lacto-fermented faeces to agriculture may be constrained by incomplete decomposition, high concentrations of organic acids or insufficient hygienization. Post-treatment by adding biochar, vermi-composting, or thermophilic composting stabilizes and sanitizes the material. Pot and field experiments on soil conditioners obtained via lactic acid fermentation and post treatment steps (composting or biochar addition) demonstrated increased crop yield and growth, as well as improved soil quality, in comparison to unfertilized controls.
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10.
Change in plasma lactate concentration during arctigenin administration in a phase I clinical trial in patients with gemcitabine-refractory pancreatic cancer.
Fujioka, R, Mochizuki, N, Ikeda, M, Sato, A, Nomura, S, Owada, S, Yomoda, S, Tsuchihara, K, Kishino, S, Esumi, H
PloS one. 2018;(6):e0198219
Abstract
Arctigenin is evaluated for antitumor efficacy in patients with pancreatic cancer. It has an inhibitory activity on mitochondrial complex I.Therefore, plasma lactate level of patients after arctigenin administration was evaluated for biomarker of clinical response and/or adverse effect. Plasma lactate level in 15 patients enrolled in a Phase I clinical trial of GBS-01 rich in arctigenin was analyzed by colorimetric assay. Statistical analyses for association of plasma lactate and clinical responses, pharmacokinetics of arctigenin, and background factors of each patient by multivariate and univariate analyses.In about half of the patients, transient increase of lactate was observed. Correlation between plasma lactate level and pharmacokinetic parameters of arctigenin and its glucuronide conjugate, and clinical outcome was not detected. Regarding to the determinant of lactate level, only slight association with liver function test was detected. Plasma lactate level is primary determined by reutilization rather than production for antitumor effect and dose not serve as a biomarker. Arctigenin, inhibition of mitochondrial complex I, plasma lactate concentration, phase I clinical trial of GBS-01, Cori cycle.