1.Manipulation of isocitrate dehydrogenase genes affects the anti-autolytic ability of lager yeast.
Kejia YE ; Haobo WU ; Chunfeng LIU ; Chengtuo NIU ; Feiyun ZHENG ; Qi LI ; Jinjing WANG
Chinese Journal of Biotechnology 2023;39(8):3451-3463
Yeast autolysis affects the flavor and quality of beer. The regulation of yeast autolysis is a need for industrial beer production. Previous studies on brewer's yeast autolysis showed that the citric acid cycle-related genes had a great influence on yeast autolysis. To explore the contribution of isocitrate dehydrogenase genes in autolysis, the IDP1 and IDP2 genes were destroyed or overexpressed in typical lager yeast Pilsner. The destruction of IDP1 gene improved the anti-autolytic ability of yeast, and the anti-autolytic index after 96 h autolysis was 8.40, 1.5 times higher than that of the original strain. The destruction of IDP1 gene increased the supply of nicotinamide adenine dinucleotide phosphate (NADPH) and the NADPH/NADP+ ratio was 1.94. After fermentation, intracellular ATP level was 1.8 times higher than that of the original strain, while reactive oxygen species (ROS) was reduced by 10%. The destruction of IDP2 gene resulted in rapid autolysis and a decrease in the supply of NADPH. Anti-autolytic index after 96 h autolysis was 4.03 and the NADPH/NADP+ ratio was 0.89. After fermentation, intracellular ATP level was reduced by 8% compared with original strain, ROS was 1.3 times higher than that of the original strain. The results may help understand the regulation mechanism of citric acid cycle-related genes on yeast autolysis and provide a basis for the selection of excellent yeast with controllable anti-autolytic performance.
Humans
;
Isocitrate Dehydrogenase/genetics*
;
NADP
;
Reactive Oxygen Species
;
Autolysis
;
Adenosine Triphosphate
2.Optimization of yeast autolysis under solid-state fermentation conditions.
Xing SU ; Zheng ZHANG ; Qiwei ZHANG ; Jingjing YANG ; Min GAO ; Honglian HU ; Dacheng LIU
Chinese Journal of Biotechnology 2019;35(4):726-736
Yeast autolysis under solid-state fermentation can effectively promote the release of various active substances, thereby improving the quality of yeast products. The optimal process for yeast autolysis under solid-state fermentation was obtained by optimizing the autolysis temperature, autolysis time and the zinc ion concentration. We analyzed the indexes of free amino acid, soluble protein and α-amino nitrogen in the fermentation material, as well as A₂₆₀/A₂₈₀ ratio to determine yeast autolysis process conditions in the solid-state fermentation. On the basis of the obtained data, L₉ (3³) orthogonal test was designed to optimize the solid-state fermentation parameters for yeast autolysis: temperature at 40, 50 and 55 °C; time 12, 18 and 24 h; zinc ion concentration 2, 4 and 8 mg/kg. The optimum process conditions for yeast autolysis were: autolysis temperature 55 °C, time 18 h, zinc ion concentration 2 mg/kg, and soluble protein content reached 9.31 mg/g, free amino acid 14.36 mg/g, α-amino nitrogen 10.16 μg/g and A₂₆₀/A₂₈₀ 1.73. After optimization of the process, the soluble protein, free amino acid and α-amino nitrogen contents of the yeast autolysis production can be significantly increased, thereby obviously improving the quality of the composite culture.
Amino Acids
;
Autolysis
;
Fermentation
;
Humans
;
Hydrogen-Ion Concentration
;
Nitrogen
;
Saccharomyces cerevisiae
;
Temperature
3.Regulations of RLM1 gene affect the anti-autolytic ability of lager yeast.
Jinjing WANG ; Mengqi LI ; Dan HOU ; Weina XU ; Feiyun ZHENG ; Chunfeng LIU ; Chengtuo NIU ; Qi LI
Chinese Journal of Biotechnology 2019;35(6):1059-1070
The autolysis of brewer's yeast seriously affects the quality of beer and the quality of yeast is considered as one of the key factors in beer brewing. Previous studies on brewer's yeast autolysis showed that RLM1 gene, an important transcription factor in cell integrity pathway, is closely related to the autolysis of yeast. In this study, RLM1 was knocked out and overexpressed in a haploid brewer's yeast. RLM1 disruption resulted in poor anti-autolysis performance of yeast, whereas overexpression of RLM1 contributed to the anti-autolytic ability of yeast. In addition, RLM1 gene knockout affected the osmotic stress resistance, cell wall damage resistance, nitrogen starvation resistance and temperature tolerance of yeast strain. The transcriptional level of GAS1 involved in cell wall assembly and DNA damage response was regulated along with the expression of RLM1, whereas other genes in CWI pathway did not show apparent regularity. RLM1 might mainly affect the expression of GAS1 so as to improve the stress resistance of lager yeast in harsh environment. The result from this study help further understand the mechanism of yeast autolysis and lay a foundation for breeding brewer's yeast strain with better anti-autolytic ability.
Autolysis
;
Beer
;
Cell Wall
;
Humans
;
MADS Domain Proteins
;
Saccharomyces cerevisiae
;
Saccharomyces cerevisiae Proteins
4.Usefulness of Dipstick Test for Vitreous Glucose in Autopsy Practice.
Kyunghong LEE ; Hyung Nam KOO ; Tae Gong KIM ; Jeong Yeol PARK ; Kang Hyun BAEK ; Seung Gyu CHOI ; Cheol Ho CHOI ; Nahyun AUM ; Nak Won LEE ; Byung Ha CHOI
Korean Journal of Legal Medicine 2016;40(4):99-103
The concentration of glucose in the vitreous humor serves as an important diagnostic marker for diabetic mellitus in post-mortem examinations, as the vitreous humor can be easily collected and the glucose test using vitreous humor is not significantly affected by cell autolysis and hemolysis. For a quick and effective glucose test, we suggest a dipstick test of the vitreous humor during autopsy. The results were evaluated and compared with other methods for significance testing. In this study, vitreous humor was analyzed from 257 autopsy cases. Qualitative concordance rate of the dipstick test for glucose and the hexokinase test was 98.7%, positive prediction rate was 89.6%, and negative prediction rate was 100%. However, there was no significant correlation between the dipstick glucose test and the hexokinase test. We conclude that the dipstick glucose test is effective and useful for post-mortem glucose screening testing and for additional post-mortem diabetes testing. Recently, the importance of post-mortem glucose testing has increased with the increase in deaths from diabetes complications. The use of the dipstick glucose test in autopsy practice can improve forensic medicine in Korea.
Autolysis
;
Autopsy*
;
Diabetes Complications
;
Forensic Medicine
;
Glucose*
;
Hemolysis
;
Hexokinase
;
Korea
;
Mass Screening
;
Vitreous Body
5.Overexpression of FKS1 to improve yeast autolysis-stress.
Jia LI ; Jinjing WANG ; Qi LI
Chinese Journal of Biotechnology 2015;31(9):1344-1354
With the development of high gravity brewing, yeast cells are exposed to multiple brewing-associated stresses, such as increased osmotic pressure, enhanced alcohol concentration and nutritional imbalance. These will speed up yeast autolysis, which seriously influence beer flavor and quality. To increase yeast anti-autolytic ability, FKS1 overexpression strain was constructed by 18S rDNA. The concentration of β-1,3-glucan of overexpression strain was 62% higher than that of wild type strain. Meantime, FKS1 overexpression strain increased anti-stress ability at 8% ethanol, 0.4 mol/L NaCl and starvation stress. Under simulated autolysis, FKS1 showed good anti-autolytic ability by slower autolysis. These results confirms the potential of FKS1 overexpression to tackle yeast autolysis in high-gravity brewing.
Autolysis
;
Beer
;
Echinocandins
;
genetics
;
Glucosyltransferases
;
genetics
;
Hypergravity
;
Membrane Proteins
;
genetics
;
Saccharomyces cerevisiae
;
cytology
;
Saccharomyces cerevisiae Proteins
;
genetics
6.Histopathological analysis of organs submitted by legal medicine experts in Baojii City: 358 forensic identification cases.
Du-xuan DONG ; Ping-xia SHI ; Yun-li LI ; San-hu TIAN ; Jia YANG ; Gang GAO ; Yun ZHENG ; Le JIA ; Hong-ya JU ; Lu-ying SUN ; Ni CHEN ; Xiao-bao WANG
Journal of Forensic Medicine 2014;30(4):273-275
OBJECTIVE:
To analyze pathological characteristics of organs recovered during forensic autopsy submitted by legal medicine experts.
METHODS:
From Baoji city, 358 cases of forensic autopsy specimens from a series of routine exams were collected. And histopathological diagnoses were reviewed.
RESULTS:
Majority of the 358 cases were young men. The major causes of death were trauma, sudden death and poisoning. The cause of death was determined with histology in 250 cases. No typical histological changes were noted in 101 cases. The tissue autolysis and decomposition were present in 7 cases. The major pathological diagnosis was cardiovascular disease, followed by diseases in respiratory, nervous, and digestive systems.
CONCLUSION
Forensic autopsy with its professional characteristics, is different from regular autopsy. When diagnosing cause of death by histopathological examination, pathologists should collaborate with legal medicine experts to know the details of the cases, circumstances surrounding the death, and specific forensic pathological characteristics.
Anxiety
;
Autolysis
;
Autopsy
;
Cardiovascular Diseases
;
Cause of Death
;
China
;
Cooperative Behavior
;
Death, Sudden
;
Female
;
Forensic Medicine
;
Forensic Pathology
;
Humans
;
Interprofessional Relations
;
Male
7.Histologic Estimation of Intrauterine Retention Time after Fetal Death.
Korean Journal of Legal Medicine 2013;37(4):191-197
The intrauterine retention time (IURT) after fetal death can be estimated from the loss of nuclear basophilia. We therefore attempted to derive an autolysis equation to estimate IURT in experimental rat fetuses and human fetal autopsy slides. The degree of loss of nuclear basophilia in various tissues was assessed by hematoxylin and eosin (H & E) staining. Fetal rat tissues showed different rates of autolysis, allowing for the construction of an experimental autolysis curve. We also reviewed the H & E stained slides obtained from 27 human fetal autopsy cases with well-documented death intervals. The degree of autolysis in various tissues was evaluated using percentile scores (PS). Using the findings from H&E staining, we derived the equation Ln (PS/[100-PS]) = 2.62716-0.02377 x IURT. However, this equation or autolysis scores showed some limitations. Owing to the inconsistency of PS, this equation is reliably applicable only within 24 hours of intrauterine fetal death. In the fetal autopsy review, fetal hydrops, local effusion, and sepsis also contributed to accelerated autolysis.
Animals
;
Autolysis
;
Autopsy
;
Eosine Yellowish-(YS)
;
Fetal Death*
;
Fetus
;
Hematoxylin
;
Humans
;
Hydrops Fetalis
;
Rats
;
Sepsis
8.Discovery of a novel gene involved in autolysis of Clostridium cells.
Liejian YANG ; Guanhui BAO ; Yan ZHU ; Hongjun DONG ; Yanping ZHANG ; Yin LI
Protein & Cell 2013;4(6):467-474
Cell autolysis plays important physiological roles in the life cycle of clostridial cells. Understanding the genetic basis of the autolysis phenomenon of pathogenic Clostridium or solvent producing Clostridium cells might provide new insights into this important species. Genes that might be involved in autolysis of Clostridium acetobutylicum, a model clostridial species, were investigated in this study. Twelve putative autolysin genes were predicted in C. acetobutylicum DSM 1731 genome through bioinformatics analysis. Of these 12 genes, gene SMB_G3117 was selected for testing the in tracellular autolysin activity, growth profile, viable cell numbers, and cellular morphology. We found that overexpression of SMB_G3117 gene led to earlier ceased growth, significantly increased number of dead cells, and clear electrolucent cavities, while disruption of SMB_G3117 gene exhibited remarkably reduced intracellular autolysin activity. These results indicate that SMB_G3117 is a novel gene involved in cellular autolysis of C. acetobutylicum.
Autolysis
;
genetics
;
Clostridium acetobutylicum
;
genetics
;
metabolism
;
Computational Biology
;
Genes, Bacterial
;
N-Acetylmuramoyl-L-alanine Amidase
;
genetics
;
metabolism
;
Temperature
9.Expression and Activity of Catalases Is Differentially Affected by GpaA (Ga) and FlbA (Regulator of G Protein Signaling) in Aspergillus fumigatus.
Mycobiology 2013;41(3):145-148
Vegetative growth signaling of the opportunistic human pathogenic fungus Aspergillus fumigatus is mediated by GpaA (Galpha). FlbA is a regulator of G protein signaling, which attenuates GpaA-mediated growth signaling in this fungus. The flbA deletion (DeltaflbA) and the constitutively active GpaA (GpaA(Q204L)) mutants exhibit enhanced proliferation, precocious autolysis, and reduced asexual sporulation. In this study, we demonstrate that both mutants also show enhanced tolerance against H2O2 and their radial growth was approximately 1.6 fold higher than that of wild type (WT) in medium with 10 mM H2O2. We performed quantitative PCR (qRT-PCR) for examination of mRNA levels of three catalase encoding genes (catA, cat1, and cat2) in WT and the two mutants. According to the results, while levels of spore-specific catA mRNA were comparable among the three strains, cat1 and cat2 mRNA levels were significantly higher in the two mutants than in WT. In particular, the DeltaflbA mutant showed significantly enhanced and prolonged expression of cat1 and precocious expression of cat2. In accordance with this result, activity of the Cat1 protein in the DeltaflbA mutant was higher than that of gpaA(Q204L) and WT strains. For activity of the Cat2 protein, both mutants began to show enhanced activity at 48 and 72 hr of growth compared to WT. These results lead to the conclusion that GpaA activates expression and activity of cat1 and cat2, whereas FlbA plays an antagonistic role in control of catalases, leading to balanced responses to neutralizing the toxicity of reactive oxygen species.
Aspergillus fumigatus*
;
Aspergillus*
;
Autolysis
;
Catalase
;
Fungi
;
GTP-Binding Proteins*
;
Humans
;
Polymerase Chain Reaction
;
Reactive Oxygen Species
;
RNA, Messenger
10.Indol-3-Carbinol Regulated Tight Junction Permeability and Associated-Protein Level and Suppressed Cell Invasion in Human Colon Cancer Cell Line, HT-29.
Sung Ok KIM ; Yung Hyun CHOI ; Won Kyung CHOE
The Korean Journal of Nutrition 2008;41(1):13-21
To determine whether indol-3-carbinol (I3C, C9H9NO), an autolysis product of a glucosinolate and a glucobrassicin in vegetables, regulated tight junction proteins (TJ) and suppressed cell invasion in colon cancer cells,this experiment was performed. Our results indicate that I3C inhibit cell growth of HT-29 cells in a dose (0, 50, 100 micrometer) and time (0, 24 and 48 h) dependent manner. Using the wound healing and matrigel invasion study, respectively, I3C inhibits the cell motility and invasion of the ovarian cancer cell line. The TEER values were increased in HT-29 cells grown in transwells treated with I3C, reversely, paracellular permeability was decreased in those of condition. Claudin-1, claudin-5, ZO-1 and occuldin have been shown to be positively expressed in HT-29 coloncancer cells. I3C occurs concurrently with a significant decrease in the levels of those of proteins in HT-29 cells. But E-cadherin level in the HT-29 was increased by I3C. The reduction of claudin-1 and claudin-5 protein levels occurred post-transcriptionaly since their mRNA levels are no difference by I3C. Therefore, our results suggest that I3C may be expected to inhibit cancer metastasis and invasion by tighten the cell junction and restoring tight junction in colon cancer cell line, HT-29.
Autolysis
;
Cadherins
;
Cell Line
;
Cell Movement
;
Claudin-1
;
Claudin-5
;
Collagen
;
Colon
;
Colonic Neoplasms
;
Drug Combinations
;
Glucosinolates
;
HT29 Cells
;
Humans
;
Indoles
;
Intercellular Junctions
;
Laminin
;
Neoplasm Metastasis
;
Ovarian Neoplasms
;
Permeability
;
Proteins
;
Proteoglycans
;
RNA, Messenger
;
Tight Junction Proteins
;
Tight Junctions
;
Vegetables
;
Wound Healing

Result Analysis
Print
Save
E-mail