1.Yinlai Decoction Protects Microstructure of Colon and Regulates Serum Level of D-Lactic Acid in Pneumonia Mice Fed with High-Calorie and High-Protein Diet.
Yun-Hui WANG ; He YU ; Tie-Gang LIU ; Teck Chuan KONG ; Zi-An ZHENG ; Yu-Xiang WAN ; Chen BAI ; Yu HAO ; Ying-Qiu MAO ; Jun WU ; Jing-Nan XU ; Li-Jun CUI ; Yu-Han WANG ; Yan-Ran SHAN ; Ying-Jun SHAO ; Xiao-Hong GU
Chinese journal of integrative medicine 2023;29(8):714-720
OBJECTIVE:
To investigate the effect of Yinlai Decoction (YD) on the microstructure of colon, and activity of D-lactic acid (DLA) and diamine oxidase (DAO) in serum of pneumonia mice model fed with high-calorie and high-protein diet (HCD).
METHODS:
Sixty male Kunming mice were randomly divided into 6 groups by the random number table method: normal control, pneumonia, HCD, HCD with pneumonia (HCD-P), YD (229.2 mg/mL), and dexamethasone (15.63 mg/mL) groups, with 10 in each group. HCD mice were fed with 52% milk solution by gavage. Pneumonia mice was modeled with lipopolysaccharide inhalation and was fed by gavage with either the corresponding therapeutic drugs or saline water, twice daily, for 3 days. After hematoxylin-eosin staining, the changes in the colon structure were observed under light microscopy and transmission electron microscope, respectively. Enzyme-linked immunosorbent assay was used to detect the protein levels of DLA and DAO in the serum of mice.
RESULTS:
The colonic mucosal structure and ultrastructure of mice in the normal control group were clear and intact. The colonic mucosal goblet cells in the pneumonia group tended to increase, and the size of the microvilli varied. In the HCD-P group, the mucosal goblet cells showed a marked increase in size with increased secretory activity. Loose mucosal epithelial connections were also observed, as shown by widened intercellular gaps with short sparse microvilli. These pathological changes of intestinal mucosa were significantly reduced in mouse models with YD treatment, while there was no significant improvement after dexamethasone treatment. The serum DLA level was significantly higher in the pneumonia, HCD, and HCD-P groups as compared with the normal control group (P<0.05). Serum DLA was significantly lower in the YD group than HCD-P group (P<0.05). Moreover, serum DLA level significantly increased in the dexamethasone group as compared with the YD group (P<0.01). There was no statistical significance in the serum level of DAO among groups (P>0.05).
CONCLUSIONS
YD can protect function of intestinal mucosa by improving the tissue morphology of intestinal mucosa and maintaining integrity of cell connections and microvilli structure, thereby reducing permeability of intestinal mucosa to regulate the serum levels of DLA in mice.
Mice
;
Male
;
Animals
;
Lactic Acid/pharmacology*
;
Intestinal Mucosa
;
Colon/pathology*
;
Dexamethasone/pharmacology*
;
Diet, High-Protein
;
Pneumonia/pathology*
2.High expression of death-associated protein 5 promotes glucose metabolism in gastric cancer cells and correlates with poor survival outcomes.
Qiusheng WANG ; Zhen ZHANG ; Lian WANG ; Yu WANG ; Xinyu YAO ; Yueyue WANG ; Xiaofeng ZHANG ; Sitang GE ; Lugen ZUO
Journal of Southern Medical University 2023;43(7):1063-1070
OBJECTIVE:
To investigate the prognostic value of death-associated protein 5 (DAP5) in gastric cancer (GC) and its regulatory effect on aerobic glycolysis in GC cells.
METHODS:
We analyzed DAP5 expression levels in GC and adjacent tissues and its association with survival outcomes of GC patients using public databases. We collected paired samples of GC and adjacent tissues from 102 patients undergoing radical resection of GC in our hospital from June, 2012 to July, 2017, and analyzed the correlation of DAP5 expression level detected immunohistochemically with the clinicopathological parameters of the patients. Cox regression analysis, Kaplan-Meier analysis, and ROC curves were used to explore the independent risk factors and the predictive value of DAP5 expression for 5-year survival of the patients. In the cell experiments, we observed the changes in aerobic glycolysis in MGC-803 cells following lentivirus-mediated DAP5 knockdown or overexpression by measuring glucose uptake and cellular lactate level and using qRT-PCR and Western blotting.
RESULTS:
Analysis using the public databases showed that DAP5 was highly expressed in GC and correlated with tumor progression and poor survival outcomes of the patients (P < 0.05). In the clinical samples, DAP5 expression was significantly higher in GC than in the adjacent tissues (3.19±0.60 vs 1.00±0.12; t=36.863, P < 0.01), and a high expression of DAP5 was associated with a reduced 5-year survival rate of the patients (17.6% vs 72.5%; χ2=29.921, P < 0.05). A high DAP5 expression, T3-4, N2-3, and CEA≥5 ng/mL were identified as independent risk factors affecting 5-year survival outcomes of GC (P < 0.05), for which DAP5 expression showed a prediction sensitivity, specificity and accuracy of 73.2%, 80.4% and 79.0%, respectively. In MGC-803 cells, DAP5 knockdown significantly reduced glucose uptake, lactate level and the expressions of GLUT1, HK2 and LDHA, and DAP5 overexpression produced the opposite effects (P < 0.05).
CONCLUSION
A high expression of DAP5 in GC, which enhances cellular aerobic glycolysis to promote cancer progression, is correlated with a poor survival outcome and may serve as a biomarker for evaluating long-term prognosis of GC patients.
Humans
;
Stomach Neoplasms
;
Blotting, Western
;
Databases, Factual
;
Glucose
;
Lactates
3.Lactate-induced up-regulation of PLEKHA4 promotes proliferation and apoptosis of human glioma cells.
Jingjing YE ; Wenqin XU ; Bangsheng XI ; Nengqian WANG ; Tianbing CHEN
Journal of Southern Medical University 2023;43(7):1071-1080
OBJECTIVE:
To investigate the effect of lactic acid-induced upregulation of PLEKHA4 expression on biological behaviors of glioma cells and the possible molecular mechanism.
METHODS:
GEO database and GEPIA2 website were used to analyze the relationship between PLEKHA4 expression level and the pathological grade of glioma. A specific PLEKHA4 siRNA was transfected in glioma U251 and T98G cells, and the changes in cell proliferation ability were assessed by real-time cell analysis technology and Edu experiment. The colony-forming ability of the cells was evaluated using plate cloning assay, and cell cycle changes and cell apoptosis were analyzed with flow cytometry. The mRNA expression of PLEKHA4 was detected by PCR in glioma samples and controls and in glioma cells treated with lactic acid and glucose. Xenograft mice in vivo was used to detect tumor formation in nude mice; Western blotting was used to detect the expressions of cyclinD1, CDK2, Bcl2, β-catenin and phosphorylation of the key proteins in the MAPK signaling pathway.
RESULTS:
The results of GEO database and online website analysis showed that PLEKHA4 was highly expressed in glioma tissues and was associated with poor prognosis; PLEKHA4 knockdown obviously inhibited the proliferation and attenuated the clone-forming ability of the glioma cells (P < 0.05). Flow cytometry showed that PLEKHA4 knockdown caused cell cycle arrest in G1 phase and promoted apoptosis of the cells (P < 0.01). PLEKHA4 gene mRNA expression was increased in glioma samples and glioma cells after lactate and glucose treatment (P < 0.01). PLEKHA4 knockdown, tumor formation ability of nude mice decreased; PLEKHA4 knockdown obviously lowered the expression of cyclinD1, CDK2, Bcl2 and other functional proteins, inhibited the phosphorylation of ERK and p38 and reduced the expression of β-catenin protein (P < 0.01).
CONCLUSION
PLEKHA4 knockdown inhibited the proliferation of glioma cells and promoted apoptosis by inhibiting the activation of the MAPK signaling pathway and expression of β-catenin. Lactic acid produced by glycolysis upregulates the expression of PLEKHA4 in glioma cells.
Humans
;
Animals
;
Mice
;
Up-Regulation
;
beta Catenin/metabolism*
;
Mice, Nude
;
Brain Neoplasms/pathology*
;
Lactic Acid
;
Cell Line, Tumor
;
Glioma/pathology*
;
Cell Proliferation
;
Apoptosis
;
Proto-Oncogene Proteins c-bcl-2/metabolism*
;
RNA, Messenger/genetics*
;
Gene Expression Regulation, Neoplastic
4.Effectiveness of 100% tea tree oil (Melaleuca alternifolia) versus salicylic acid + lactic acid solution in the treatment of common warts: A randomized controlled trial
Zacaria B. Pario Jr. ; Lalaine R. Visitacion ; Bai Shariffah B. Pandita‑Reyes
Journal of the Philippine Dermatological Society 2023;32(2):90-95
Background:
Common warts are a common malady among patients. Not only does it affect the person physically but also mentally and socially. Several treatment modalities are available; however, the major concerns are the treatment cost and adverse effect profile. Salicylic + lactic acid (SLA) solution is one of the standard treatment modalities owing to its strong keratolytic properties; however, its cost and adverse effects limit its use among patients. A cost-effective and safe alternative treatment is ideal to bring about a more favorable clinical outcome and better patient satisfaction. 100% tea tree oil (TTO) solution was used in this study due to its natural antiviral and anti-inflammatory properties.
Objective:
The study aimed to compare the safety and effectiveness of 100% TTO versus SLA solution in the treatment of common warts.
Methods:
A total of 17 patients with a total of 74 warts were included in the study. Each wart was assigned to either of the two treatment groups. the SLA group and the 100% TTO group. A treatment period of 6 weeks was used to assess the effectiveness of both treatment groups.
Results:
The study showed no significant difference between the SLA solution and 100% TTO in the treatment of common warts. The 100% tea tree group reported lesser adverse effects. Both treatment groups reported favorable treatment satisfaction.
Conclusion
100% TTO is a potentially safe and cost-effective alternative in the treatment of common warts.
Lactic Acid
;
Salicylic Acid
;
Tea Tree Oil
5.The "weekend effect" does not impact on outcome of trauma laparotomy - Experience from a level 1 trauma centre in New Zealand.
Jonathan KO ; Victor KONG ; Janet AMEY ; Damien Ah YEN ; Damian CLARKE ; Grant CHRISTEY
Chinese Journal of Traumatology 2023;26(2):73-76
PURPOSE:
Trauma centres have been proven to provide better outcomes in developed countries for overall trauma, but there is limited literature on the systematic factors that describe any discrepancies in outcomes for trauma laparotomies in these centres. This study was conducted to examine and interrogate the effect of systematic factors on patients undergoing a trauma laparotomy in a developed country, intending to identify potential discrepancies in the outcome.
METHODS:
This was a retrospective study of all laparotomies performed for trauma at a level 1 trauma centre in New Zealand. All adult patients who had undergone an index laparotomy for trauma between February 2012 and November 2020 were identified and laparotomies for both blunt and penetrating trauma were included. Repeat laparotomies and trauma laparotomies in children were excluded. The primary clinical outcomes reviewed included morbidity, length of hospital stay, and mortality. All statistical analysis was performed using R v.4.0.3.
RESULTS:
During the 9-year study period, 204 trauma laparotomies were performed at Waikato hospital. The majority (83.3%) were performed during office hours (170/204), and the remaining 16.7% were performed after hours (34/204). And 61.3% were performed on a weekday (125/204), whilst 38.7% were performed on the weekend/public holiday (79/204). Most of the parameters in office hours and after hours groups had no statistically significant difference, except lactate (p = 0.026). Most of the variables in weekday and weekend groups had no statistically significant difference, except pH, lactate, length of stay, and gastrointestinal complications (p = 0.012, p < 0.001, p = 0.003, p = 0.020, respectively).
CONCLUSION
The current trauma system at Waikato hospital is capable of delivering care for trauma laparotomy patients with the same outcome regardless of working hours or after hours, weekday or weekend. This confirms the importance of a robust trauma system capable of responding to the sudden demands placed on it.
Adult
;
Child
;
Humans
;
Laparotomy
;
Trauma Centers
;
Retrospective Studies
;
New Zealand/epidemiology*
;
Lactic Acid
;
Abdominal Injuries/surgery*
6.Prognostic value of serum sodium variability within 72 hours and lactic acid combined with severity score in patients with sepsis.
Hang CHI ; Hongliang WANG ; Qingshu LI ; Zhiyuan LIAN ; Canxiu ZHANG ; Shuhu ZHANG ; Dan HU
Chinese Critical Care Medicine 2023;35(5):458-462
OBJECTIVE:
To explore the predictive value of serum sodium variability within 72 hours, lactic acid (Lac), sequential organ failure assessment (SOFA) and acute physiology and chronic health evaluation II (APACHE II) in predicting the 28-day prognosis of sepsis patients.
METHODS:
The clinical data of patients with sepsis admitted to the department of intensive care unit (ICU) of the Affiliated Qingdao Municipal Hospital of Qingdao University from December 2020 to December 2021 were retrospectively analyzed, including age, gender, previous medical history, temperature, heart rate, respiratory rate, systolic pressure, diastolic pressure, white blood cell count (WBC), hemoglobin (Hb), platelet count (PLT), C-reactive protein (CRP), pH value, arterial partial pressure of oxygen (PaO2), arterial partial pressure of carbon dioxide (PaCO2), Lac, prothrombin time (PT), activated partial thromboplastin time (APTT), serum creatinine (SCr), total bilirubin (TBil), albumin (Alb), SOFA, APACHE II score, and 28-day prognosis. Multivariate Logistic regression was used to analyze the risk factors of death in sepsis patients. Receiver operator characteristic curve (ROC curve) was used to analyze the predictive value of serum sodium variability within 72 hours, Lac, SOFA, APACHE II alone and in combination on the prognosis of patients with sepsis.
RESULTS:
A total of 135 patients with sepsis were included, 73 survived and 62 died at 28 days, with 28-day mortality of 45.93%. (1) Compared with the survival group, SOFA, APACHE II, Lac and serum sodium variability within 72 hours in the death group were significantly higher [SOFA: 10.00 (8.00, 12.00) vs. 6.00 (5.00, 8.00), APACHE II: 18.00 (16.00, 21.25) vs. 13.00 (11.00, 15.00), Lac (mmol/L): 3.55 (2.90, 4.60) vs. 2.00 (1.30, 2.80), serum sodium variability within 72 hours: 3.4% (2.6%, 4.2%) vs. 1.4% (1.1%, 2.5%)], the differences were statistically significant (all P < 0.01). (2) Multivariate Logistic regression showed that SOFA, APACHE II, Lac, serum sodium variability within 72 hours were independent risk factors of prognosis in patients with sepsis [SOFA: odds ratio (OR) = 1.479, 95% confidence interval (95%CI) was 1.114-1.963, P = 0.007; APACHE II: OR = 1.163, 95%CI was 1.009-1.340, P = 0.037; Lac: OR = 1.387, 95%CI was 1.014-1.896, P = 0.040; serum sodium variability within 72 hours: OR = 1.634, 95%CI was 1.102-2.423, P = 0.015]. (3) ROC curve analysis showed that SOFA, APACHE II, Lac and serum sodium variability within 72 hours had certain predictive value for the prognosis of sepsis patients [SOFA: the area under the ROC curve (AUC) = 0.858, 95%CI was 0.795-0.920, P = 0.000; APACHE II: AUC = 0.845, 95%CI was 0.776-0.913, P = 0.000; Lac: AUC = 0.840, 95%CI was 0.770-0.909, P = 0.000; serum sodium variability within 72 hours: AUC = 0.842, 95%CI was 0.774-0.910, P = 0.000]. The combined predictive value of the four indicators (AUC = 0.917, 95%CI was 0.870-0.965, P = 0.000) was higher than that of any single indicator, and has higher specificity (79.5%) and sensitivity (93.5%), indicating that the combined index has higher predictive value for the prognosis of sepsis patients than any single index.
CONCLUSIONS
SOFA, APACHE II, Lac, serum sodium variability within 72 hours are independent risk factors for 28-day death in patients with sepsis. The combination of SOFA score, APACHE II score, Lac and serum sodium variability within 72 hours has higher predictive value for prognosis than single index.
Humans
;
Lactic Acid
;
Prognosis
;
Retrospective Studies
;
Sepsis
;
Sodium
7.Correlation between four limbs perfusion index and lactic acid in patients with severe neurological diseases.
Wen GUO ; Long MA ; Tuerxun TUERHONG ; Xiaopeng LI ; Bo LIU ; Zhiyi XIE ; Xiangyou YU
Chinese Critical Care Medicine 2023;35(5):509-512
OBJECTIVE:
To observe the correlation between the four limbs perfusion index (PI) and blood lactic acid in patients with neurosis, and evaluate the predictive value of PI on microcirculation perfusion metabolic disorder in patients with neurosis.
METHODS:
A prospective observational study was conducted. Adult patients admitted to the department of neurological intensive care unit (NICU) of the First Affiliated Hospital of Xinjiang Medical University from July 1 to August 20 in 2020 were enrolled. Under the condition of indoor temperature controlled at 25 centigrade, all patients were placed in the supine position, and the blood pressure, heart rate, PI of both fingers and thumb toes and arterial blood lactic acid were measured within 24 hours and 24-48 hours after NICU. The difference of four limbs PI at different time periods and its correlation with lactic acid were compared. Receiver operator characteristic curve (ROC curve) was used to evaluate the predictive value of four limbs PI on patients with microcirculatory perfusion metabolic disorder.
RESULTS:
A total of 44 patients with neurosis were enrolled, including 28 males and 16 females; average age (61.2±16.5) years old. There were no significant differences in PI of the left index finger and the right index finger [2.57 (1.44, 4.79) vs. 2.70 (1.25, 5.33)], PI of the left toe and the right toe [2.09 (0.85, 4.76) vs. 1.88 (0.74, 4.32)] within 24 hours after entering the NICU, and the PI of the left index finger and the right index finger [3.17 (1.49, 5.07) vs. 3.14 (1.33, 5.36)], PI of the left toe and the right toe [2.07 (0.75, 5.20) vs. 2.07 (0.68, 4.67)] at 24-48 hours after NICU admission (all P > 0.05). However, compared to the PI of the upper and lower limbs on the same side, except for the 24-48 hours after ICU of the PI difference between the left index finger and the left toe (P > 0.05), the PI of the toe was lower than that of the index finger at the other time periods (all P < 0.05). The correlation analysis showed that the PI value of four limbs of patients in both time periods were significantly negatively correlated with arterial blood lactic acid (the r values of the left index finger, the right index finger, the left toe and the right toe were -0.549, -0.482, -0.392 and -0.343 respectively within 24 hours after entering the NICU; the r values of the left index finger, the right index finger, the left toe and the right toe were -0.331, -0.292, -0.402 and -0.442 respectively after entering the NICU 24-48 hours, all P < 0.05). Taking lactic acid ≥ 2 mmol/L as the diagnostic standard for metabolic disorder of microcirculation perfusion (total 27 times, accounting for 30.7%). The efficacy of four limbs PI in predicting microcirculation perfusion metabolic disorder were compared. ROC curve analysis showed that the area under the curve (AUC) and 95% confidence interval (95%CI) of left index finger, right index finger, left toe and right toe predicting microcirculation perfusion metabolic disorder were 0.729 (0.609-0.850), 0.767 (0.662-0.871), 0.722 (0.609-0.835), 0.718 (0.593-0.842), respectively. There was no significant difference in AUC compare with each other (all P > 0.05). The cut-off value of PI of right index finger for predicting microcirculation perfusion metabolic disorder was 2.46, the sensitivity was 70.4%, the specificity was 75.4%, the positive likelihood ratio was 2.86, and the negative likelihood ratio was 0.30.
CONCLUSIONS
There are no significant differences in PI of bilateral index fingers, bilateral toes in patients with neurosis. However, unilateral upper and lower limbs showed lower PI in the toe than in the index finger. There is a significantly negatively correlation between PI and arterial blood lactic acid in all four limbs. PI can predict the metabolic disorder of microcirculation perfusion, and its cut-off value is 2.46.
Adult
;
Female
;
Male
;
Humans
;
Middle Aged
;
Aged
;
Lactic Acid
;
Microcirculation
;
Perfusion Index
;
Lower Extremity
;
Area Under Curve
;
Nervous System Diseases
8.Analysis of clinical characteristics and risk factors of early heat stroke-related acute liver injury.
Aiming LIU ; Zunguo PU ; Lulu CHU ; Hongsheng DING ; Yaqing ZHOU
Chinese Critical Care Medicine 2023;35(7):724-729
OBJECTIVE:
To analyze the clinical characteristics and risk factors of early acute liver injury in patients with heat stroke (HS), and to provide basis for early identification of HS-related liver injury and its pathogenesis in clinical practice.
METHODS:
The clinical data of patients with HS admitted to the department of critical care medicine of Haian People's Hospital from June 2015 to August 2022 were retrospectively analyzed. The patients with HS were divided into early liver injury group and early non-liver injury group according to the occurrence of acute liver injury within 24 hours of admission. The differences of basic data, clinical data, laboratory indexes and clinical outcomes of the two groups were analyzed. Logistic regression was used to analyze the risk factors for early HS-related acute liver injury, and receiver operator characteristic (ROC) curves were drawn to evaluate their value in predicting the occurrence of early HS-related acute liver injury.
RESULTS:
A total of 76 patients with HS were enrolled, and 46 patients with acute liver injury, accounting for 60.53%. In the early liver injury group, 14 patients (30.43%) had elevated aminotransferase alone, 9 patients (19.57%) had elevated total bilirubin (TBil) alone, and 23 patients (50.00%) had elevated both aminotransferase and TBil. Among the patients with elevated aminotransferases, 24 patients (64.87%) had mild elevation, 5 patients (13.51%) had moderate elevation, 8 patients (21.62%) had severe elevation. Compared with the early non-liver injury group, acute physiology and chronic health evaluation II (APACHE II), sequential organ failure assessment (SOFA), arterial blood lactate (Lac), interleukin-6 (IL-6), procalcitonin (PCT), alanine aminotransferase (ALT), aspartate aminotransferase (AST), TBil, γ-gamma glutamyl transferase (γ-GGT), lactate dehydrogenase (LDH), creatine kinase (CK), MB isoenzyme of creatine kinase (CK-MB), cardiac troponin I (cTnI), myoglobin (MYO), N-terminal B-type pro-brain natriuretic peptide (NT-proBNP), prothrombin time (PT), activated partial thromboplastin time (APTT), D-dimer in the early liver injury group were significantly increased, while platelet count (PLT) were significantly decreased within 24 hours after admission, the 28-day mortality was significantly increased [28.26% (13/46) vs. 6.67% (2/30)], and the differences were statistically significant (all P < 0.05). Univariate Logistic regression analysis showed that APACHE II score, SOFA score, PLT, Lac, IL-6, PCT, γ-GGT, LDH, CK, CK-MB, cTnI, MYO, PT, APTT, D-dimer were risk factors of early HS-related acute liver injury (all P < 0.05). Multivariate Logistic regression analysis showed that PLT, IL-6, and LDH were independent risk factors of early HS-related acute liver injury [odds ratio (OR) and 95% confidence interval (95%CI) were 0.986 (0.974-0.998), 1.027 (1.012-1.041), and 1.002 (1.000-1.004), all P < 0.05]. The ROC curve analysis showed that the area under the ROC curve (AUC) of PLT, IL-6 and LDH for predicting the occurrence of early HS-related acute liver injury was 0.672 (95%CI was 0.548-0.797), 0.897 (95%CI was 0.824-0.971) and 0.833 (95%CI was 0.739-0.927), respectively. IL-6 had the highest predictive value for early HS-related liver injury. When the optimal diagnostic threshold of IL-6 was 48.25 ng/L, the sensitivity was 95.7%, the specificity was 73.3%, and the predictive value of PLT was the lowest.
CONCLUSIONS
The early HS-related liver injury is mainly manifested as the simultaneous elevation of aminotransferase and TBil, and most of cases are mild liver injury. PLT, IL-6 and LDH are independent risk factors of early HS-related acute liver injury.
Humans
;
Prognosis
;
Retrospective Studies
;
Interleukin-6
;
ROC Curve
;
Sepsis/diagnosis*
;
Heat Stroke/complications*
;
Risk Factors
;
Alanine Transaminase
;
Creatine Kinase, MB Form
;
Lactic Acid
;
Creatine Kinase
9.Immobilization of Lactobacillus bulgaricus with gellan gum and its application in continuous fermentation of D-lactic acid from corn straw.
Yongxin GUO ; Gang WANG ; Kexin LI ; Jiaqi HAN ; Huan CHEN ; Sitong ZHANG ; Yanli LI ; Guang CHEN
Chinese Journal of Biotechnology 2023;39(3):1083-1095
Biorefinery of chemicals from straw is an effective approach to alleviate the environmental pollution caused by straw burning. In this paper, we prepared gellan gum immobilized Lactobacillus bulgaricus T15 gel beads (LA-GAGR-T15 gel beads), characterized their properties, and established a continuous cell recycle fermentation process for D-lactate (D-LA) production using the LA-GAGR-T15 gel beads. The fracture stress of LA-GAGR-T15 gel beads was (91.68±0.11) kPa, which was 125.12% higher than that of the calcium alginate immobilized T15 gel beads (calcium alginate-T15 gel beads). This indicated that the strength of LA-GAGR-T15 gel beads was stronger, and the strain was less likely to leak out. The average D-LA production was (72.90±2.79) g/L after fermentation for ten recycles (720 h) using LA-GAGR-T15 gel beads as the starting strain and glucose as the substrate, which was 33.85% higher than that of calcium alginate-T15 gel beads and 37.70% higher than that of free T15. Subsequently, glucose was replaced by enzymatically hydrolyzed corn straw and fermented for ten recycles (240 h) using LA-GAGR-T15 gel beads. The yield of D-LA reached (1.74±0.79) g/(L·h), which was much higher than that of using free bacteria. The wear rate of gel beads was less than 5% after ten recycles, which indicated that LA-GAGR is a good carrier for cell immobilization and can be widely used in industrial fermentation. This study provides basic data for the industrial production of D-LA using cell-recycled fermentation, and provides a new way for the biorefinery of D-LA from corn straw.
Fermentation
;
Lactobacillus delbrueckii
;
Zea mays
;
Lactic Acid
;
Alginates/chemistry*
;
Glucose
10.Using transporter to enhance the acid tolerance of Bacillus coagulans DSM1.
Jing LI ; Yu WANG ; Bo YU ; Limin WANG ; Jiansong JU
Chinese Journal of Biotechnology 2023;39(8):3394-3405
As the precursor of polylactic acid (PLA), optically pure l-lactic acid production is attracting increasing attention. The accumulation of lactic acid during fermentation inhibits strain growth. Therefore, it is necessary to improve the acid tolerance of lactic acid producers. In this study, comparative transcriptomic analysis was performed to investigate the effects of transporters on lactic acid tolerance of Bacillus coagulans DSM1, which is an l-lactic acid producer. The genes with more than two-fold up-regulation in transcriptional profile were further verified using real-time PCR. The transcriptional levels of RS06895, RS10595, RS10595, RS00500, RS00500, RS10635 and RS10635 were enhanced during lactic acid fermentation. Strain overexpressing RS10595 exhibited a retarded cell growth and low lactic acid production at pH 6.0, but an improved lactic acid production at pH 4.6. This study may facilitate the investigation of the acid tolerance mechanism in B. coagulans DSM1, as well as the construction of efficient lactic acid producers.
Bacillus coagulans/genetics*
;
Lactic Acid
;
Cell Cycle
;
Cell Proliferation
;
Fermentation


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