Biotechnological Production of Lactic Acid and Its Recent Applications

Mliječna se kiselina upotrebljava u prehrambenoj, kozmetičkoj, farmaceutskoj i kemijskoj industriji te sve više i kao monomer za proizvodnju biorazgradljive (poli)mliječne kiseline. Mliječna se kiselina može proizvesti biotehnološkim procesom ili kemijskom sintezom. U novije se vrijeme sve više koristi biotehnološki postupak zbog zaštite okoliša i ograničene količine petrokemijskih izvora. Na različite načine pokušala se proizvesti mliječna kiselina iz jeftinih sirovina. U ovom su radu prikazani mikroorganizmi i sirovine za proizvodnju mliječne kiseline, njezina biotehnološka proizvodnja te načini primjene, a osobito najnovija istraživanja. Također se raspravlja o mogućnosti i ekonomskoj važnosti primjene mliječne kiseline u budućnosti.Lactic acid is widely used in the food, cosmetic, pharmaceutical, and chemical industries and has received increased attention for use as a monomer for the production of biodegradable poly(lactic acid). It can be produced by either biotechnological fermentation or chemical synthesis, but the former route has received considerable interest recently, due to environmental concerns and the limited nature of petrochemical feedstocks. There have been various attempts to produce lactic acid efficiently from inexpensive raw materials. We present a review of lactic acid-producing microorganisms, raw materials for lactic acid production, fermentation approaches for lactic acid production, and various applications of lactic acid, with a particular focus on recent investigations. In addition, the future potentials and economic impacts of lactic acid are discussed

Characterization of Cep135, a novel coiled-coil centrosomal protein involved in microtubule organization in mammalian cells

By using monoclonal antibodies raised against isolated clam centrosomes, we have identified a novel 135-kD centrosomal protein (Cep135), present in a wide range of organisms. Cep135 is located at the centrosome throughout the cell cycle, and localization is independent of the microtubule network. It distributes throughout the centrosomal area in association with the electron-dense material surrounding centrioles. Sequence analysis of cDNA isolated from CHO cells predicted a protein of 1,145–amino acid residues with extensive α-helical domains. Expression of a series of deletion constructs revealed the presence of three independent centrosome-targeting domains. Overexpression of Cep135 resulted in the accumulation of unique whorl-like particles in both the centrosome and the cytoplasm. Although their size, shape, and number varied according to the level of protein expression, these whorls were composed of parallel dense lines arranged in a 6-nm space. Altered levels of Cep135 by protein overexpression and/or suppression of endogenous Cep135 by RNA interference caused disorganization of interphase and mitotic spindle microtubules. Thus, Cep135 may play an important role in the centrosomal function of organizing microtubules in mammalian cells

Pilot-Scale Lactic Acid Production via Batch Culturing of Lactobacillus sp. RKY2 Using Corn Steep Liquor As a Nitrogen Source

U ovom se istraživanju pokušala odrediti učinkovitost proizvodnje mliječne kiseline uzgojem soja Lactobacillus sp. RKY2 u pilot-postrojenju uporabom kukuruznog ekstrakta kao izvora dušika. Količina mliječne kiseline nakon fermentacije, rast stanica, prinos i produktivnost nisu se bitno promijenili dodatkom čiste glukoze pri povećanju obujma procesa s 2,5 na 30 i 300 L. U svim pokusima udio mliječne kiseline linearno se povećavao s porastom početne koncentracije glukoze. U pokusu s hidrolizatom drva smanjili su se produktivnost mliječne kiseline i rast stanica s povećanjem obujma procesne opreme, zbog toksičnih kemikalija iz hidrolizata. Međutim, u svim je pokusima prinos mliječne kiseline bio veci od 90 % bez obzira na utrošak glukoze. Zaključeno je da je mliječna kiselina uspješno proizvedena u pilot-postrojenju upotrijebljenom u ovom istraživanju.In this study, the determination of the efficiency of a pilot-scale fermentation process using corn steep liquor as a nitrogen source was attempted in order to produce lactic acid via batch culturing of Lactobacillus sp. RKY2. Using pure glucose, fermentation efficiency characteristics, such as final lactic acid, cell growth, yield, and productivity were not substantially influenced by the scale-up of the laboratory-scale fermentation from 2.5- to 30- and 300-litre scale fermentations. In all experiments, the content of lactic acid produced increased in a linear fashion with increases in the initial glucose concentration. In the experiments using wood hydrolyzate, both lactic acid productivity and cell growth were decreased as a result of the scaling-up of the fermentation. This might be attributed to the toxic chemicals contained in the wood hydrolyzates. However, in all experiments, lactic acid yields remained higher than 90 % with regard to the amount of glucose consumed. Therefore, lactic acid was successfully produced by the pilot-scale bioreactor scheme adopted in this study

Pilot-Scale Lactic Acid Production via Batch Culturing of Lactobacillus sp. RKY2 Using Corn Steep Liquor As a Nitrogen Source

U ovom se istraživanju pokušala odrediti učinkovitost proizvodnje mliječne kiseline uzgojem soja Lactobacillus sp. RKY2 u pilot-postrojenju uporabom kukuruznog ekstrakta kao izvora dušika. Količina mliječne kiseline nakon fermentacije, rast stanica, prinos i produktivnost nisu se bitno promijenili dodatkom čiste glukoze pri povećanju obujma procesa s 2,5 na 30 i 300 L. U svim pokusima udio mliječne kiseline linearno se povećavao s porastom početne koncentracije glukoze. U pokusu s hidrolizatom drva smanjili su se produktivnost mliječne kiseline i rast stanica s povećanjem obujma procesne opreme, zbog toksičnih kemikalija iz hidrolizata. Međutim, u svim je pokusima prinos mliječne kiseline bio veci od 90 % bez obzira na utrošak glukoze. Zaključeno je da je mliječna kiselina uspješno proizvedena u pilot-postrojenju upotrijebljenom u ovom istraživanju.In this study, the determination of the efficiency of a pilot-scale fermentation process using corn steep liquor as a nitrogen source was attempted in order to produce lactic acid via batch culturing of Lactobacillus sp. RKY2. Using pure glucose, fermentation efficiency characteristics, such as final lactic acid, cell growth, yield, and productivity were not substantially influenced by the scale-up of the laboratory-scale fermentation from 2.5- to 30- and 300-litre scale fermentations. In all experiments, the content of lactic acid produced increased in a linear fashion with increases in the initial glucose concentration. In the experiments using wood hydrolyzate, both lactic acid productivity and cell growth were decreased as a result of the scaling-up of the fermentation. This might be attributed to the toxic chemicals contained in the wood hydrolyzates. However, in all experiments, lactic acid yields remained higher than 90 % with regard to the amount of glucose consumed. Therefore, lactic acid was successfully produced by the pilot-scale bioreactor scheme adopted in this study

A More Appropriate Cardiac Troponin T Level That Can Predict Outcomes in End-Stage Renal Disease Patients with Acute Coronary Syndrome

Purpose: Cardiac troponin T (cTnT), a useful marker for diagnosing acute myocardial infarction (AMI) in the general population, is significantly higher than the usual cut-off value in many end-stage renal disease (ESRD) patients without clinically apparent evidence of AMI. The aim of this study was to evaluate the clinical usefulness of cTnT in ESRD patients with acute coronary syndrome (ACS). Materials and methods: Two hundred eighty-four ESRD patients with ACS were enrolled between March 2002 and February 2008. These patients were followed until death or June 2009. Medical records were reviewed retrospectively. The cut-off value of cTnT for AMI was evaluated using a receiver operating characteristic (ROC) curve. We calculated Kaplan-Meier survival curves, and potential outcome predictors were determined by Cox proportional hazard analysis. Results: AMIs were diagnosed in 40 patients (14.1%). The area under the curve was 0.98 in the ROC curve (p<0.001; 95% CI, 0.95-1.00). The summation of sensitivity and specificity was highest at the initial cTnT value of 0.35 ng/mL (sensitivity, 0.95; specificity, 0.97). Survival analysis showed a statistically significant difference in all-cause and cardiovascular mortalities for the group with an initial cTnT ≥0.35 ng/mL compared to the other groups. Initial serum cTnT concentration was an independent predictor for mortality. Conclusion: Because ESRD patients with an initial cTnT concentration ≥0.35 ng/mL have a poor prognosis, it is suggested that urgent diagnosis and treatment be indicated in dialysis patients with ACS when the initial cTnT levels are ≥0.35 ng/mL.ope

Increased pulsatility index of the basilar artery is a risk factor for neurological deterioration after stroke: a case control study

Background : Higher pulsatility of the middle cerebral artery (MCA) is known to be associated with stroke progression. We investigated whether pulsatility index (PI) of the basilar artery (BA) can predict neurological deterioration (ND) after acute cerebral infarction. Methods : A total of 708 consecutive patients with acute ischemic stroke who had undergone transcranial Doppler (TCD) ultrasonography were included. ND was defined as an increase in the National Institutes of Health Stroke Scale scores by two or more points after admission. The patients were categorized into quartiles according to BA PI. Multivariable logistic regression analysis was performed to examine whether BA PI is independently associated with ND. Results : BA PI was well correlated with the right (n = 474, r2 = 0.573, P < 0.001) by Pearson correlation analysis although MCA PI could not be measured from right MCA (n = 234, 33.05%) and left MCA (n = 252, 35.59%) by TCD owing to insufficient temporal bone window. Multivariable logistic regression analysis including age, sex, cerebral atherosclerosis burden, National Institutes of Health Stroke Scale at admission, and the proportion of patients with current smoking status, hypertension, diabetes mellitus, atrial fibrillation revealed that the higher BA PI (odds ratio, 3.28; confidence interval, 1.07–10.17; P = 0.038) was independently associated with ND. Conclusions : BA PI, which would be identified regardless of temporal window, could predict ND among acute stroke patients.The work was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2017R1D1A1B03029909, NRF-2019R1F1A1059455) and by the Korean Society of Hypertension (2019). The funding has no role in design, collection, analysis, or interpretation of data; in the writing of the manuscript; and in the decision to submit the manuscript for publication

Microporation is a valuable transfection method for efficient gene delivery into human umbilical cord blood-derived mesenchymal stem cells

<p>Abstract</p> <p>Background</p> <p>Mesenchymal stem cells (MSCs) are an attractive source of adult stem cells for therapeutic application in clinical study. Genetic modification of MSCs with beneficial genes makes them more effective for therapeutic use. However, it is difficult to transduce genes into MSCs by common transfection methods, especially nonviral methods. In this study, we applied microporation technology as a novel electroporation technique to introduce enhanced green fluorescent protein (EGFP) and brain-derived neurotropfic factor (BDNF) plasmid DNA into human umbilical cord blood-derived MSCs (hUCB-MSCs) with significant efficiency, and investigated the stem cell potentiality of engineered MSCs through their phenotypes, proliferative capacity, ability to differentiate into multiple lineages, and migration ability towards malignant glioma cells.</p> <p>Results</p> <p>Using microporation with EGFP as a reporter gene, hUCB-MSCs were transfected with higher efficiency (83%) and only minimal cell damage than when conventional liposome-based reagent (<20%) or established electroporation methods were used (30-40%). More importantly, microporation did not affect the immunophenotype of hUCB-MSCs, their proliferation activity, ability to differentiate into mesodermal and ectodermal lineages, or migration ability towards cancer cells. In addition, the BDNF gene could be successfully transfected into hUCB-MSCs, and BDNF expression remained fairly constant for the first 2 weeks <it>in vitro </it>and <it>in vivo</it>. Moreover, microporation of BDNF gene into hUCB-MSCs promoted their <it>in vitro </it>differentiation into neural cells.</p> <p>Conclusion</p> <p>Taken together, the present data demonstrates the value of microporation as an efficient means of transfection of MSCs without changing their multiple properties. Gene delivery by microporation may enhance the feasibility of transgenic stem cell therapy.</p

The Korean Organ Transplantation Registry (KOTRY): an overview and summary of the kidney-transplant cohort

Background As the need for a nationwide organ-transplant registry emerged, a prospective registry, the Korean Organ Transplantation Registry (KOTRY), was initiated in 2014. Here, we present baseline characteristics and outcomes of the kidney-transplant cohort for 2014 through 2019. Methods The KOTRY consists of five organ-transplant cohorts (kidney, liver, lung, heart, and pancreas). Data and samples were prospectively collected from transplant recipients and donors at baseline and follow-up visits; and epidemiological trends, allograft outcomes, and patient outcomes, such as posttransplant complications, comorbidities, and mortality, were analyzed. Results From 2014 to 2019, there were a total of 6,129 registered kidney transplants (64.8% with living donors and 35.2% with deceased donors) with a mean recipient age of 49.4 ± 11.5 years, and 59.7% were male. ABO-incompatible transplants totaled 17.4% of all transplants, and 15.0% of transplants were preemptive. The overall 1- and 5-year patient survival rates were 98.4% and 95.8%, respectively, and the 1- and 5-year graft survival rates were 97.1% and 90.5%, respectively. During a mean follow-up of 3.8 years, biopsy-proven acute rejection episodes occurred in 17.0% of cases. The mean age of donors was 47.3 ± 12.9 years, and 52.6% were male. Among living donors, the largest category of donors was spouses, while, among deceased donors, 31.2% were expanded-criteria donors. The mean serum creatinine concentrations of living donors were 0.78 ± 0.62 mg/dL and 1.09 ± 0.24 mg/dL at baseline and 1 year after kidney transplantation, respectively. Conclusion The KOTRY, a systematic Korean transplant cohort, can serve as a valuable epidemiological database of Korean kidney transplants