1.Engineering of CmpLs enhances L-glutamate production of Corynebacterium glutamicum.
Xingtao ZUO ; Shasha ZHONG ; Ningyun CAI ; Tuo SHI ; Zhidan ZHANG ; Yuantao LIU ; Jiao LIU ; Depei WANG ; Jiuzhou CHEN ; Ping ZHENG
Chinese Journal of Biotechnology 2025;41(1):271-287
The efficient production of L-glutamate is dependent on the product's rapid efflux, hence researchers have recently concentrated on artificially modifying its transport system and cell membrane wall structure. Considering the unique composition and structure of the cell wall of Corynebacterium glutamicum, we investigated the effects of CmpLs on L-glutamate synthesis and transport in SCgGC7, a constitutive L-glutamate efflux strain. First, the knockout strains of CmpLs were constructed, and it was confirmed that the deletion of CmpL1 and CmpL4 significantly improved the performance of L-glutamate producers. Next, temperature-sensitive L-glutamate fermentation with the CmpL1 and CmpL4 knockout strains were carried out in 5 L bioreactors, where the knockout strains showcased temperature-sensitive characteristics and enhanced capacities for L-glutamate production under high temperatures. Notably, the CmpL1 knockout strain outperformed the control strain in terms of L-glutamate production, showing production and yield increases of 69.2% and 55.3%, respectively. Finally, the intracellular and extracellular metabolites collected at the end of the fermentation process were analyzed. The modification of CmpLs greatly improved the L-glutamate excretion and metabolic flux for both L-glutamate production and transport. Additionally, the CmpL1 knockout strain showed decreased accumulation of downstream metabolites of L-glutamate and intermediate metabolites of tricarboxylic acid (TCA) cycle, which were consistent with its high L-glutamate biosynthesis capacity. In addition to offering an ideal target for improving the stability and performance of the industrial strains for L-glutamate production, the functional complementarity and redundancy of CmpLs provide a novel target and method for improving the transport of other metabolites by modification of the cell membrane and cell wall structures in C. glutamicum.
Corynebacterium glutamicum/genetics*
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Glutamic Acid/biosynthesis*
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Fermentation
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Metabolic Engineering
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Bacterial Proteins/metabolism*
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Bioreactors/microbiology*
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Gene Knockout Techniques
2.Characteristics of pathological changes of the sclera in high myopia and rela-ted regulatory molecules
Dongmei YANG ; Gang LIANG ; Jun LI ; Jing ZHAO ; Zhi CHEN ; Xingtao ZHOU
Recent Advances in Ophthalmology 2025;45(1):55-59
High myopia is a refractive abnormality characterized by excessive elongation of the eye axis.The sclera,as an important part of the eye axis regulation,plays a key role in the occurrence and development of high myopia.In this pa-per,based on the domestic and international articles,the pathological changes and related regulatory molecules of the scle-ra in high myopia were systematically summarized from the features of scleral lesions in high myopia and the gene regula-tion and signaling pathways affecting the ultrastructure and mechanical properties of the sclera,thus providing a theoretical basis for the study of the pathological mechanism of high myopia.
3.Investigation and disposal of a pseudo-outbreak of Pseudomonas fluorescens detected from bronchoalveolar lavage fluid
Feng CHEN ; Dijun LIU ; Renjian HUANG ; Min HOU ; Ziyun HUANG ; Kai-jia WANG ; Xingtao YI
Chinese Journal of Infection Control 2025;24(9):1307-1313
Objective To investigate the causes for the continuous detection of Pseudomonas fluorescens(P.fluo-rescens)from bronchoalveolar lavage fluid(BALF)in pediatric department of a hospital,formulate intervention measures and evaluate its effectiveness,and provide basis for improving the whole process infection control of fiber bronchoscopy.Methods Epidemiological investigation was conducted on three children from whose BALF P.fluorescens were detected in May 3-6,2024.The comprehensive methods were adopted,including case revie-wing,on-site process tracking,environmental hygiene monitoring,laboratory testing on disinfectant sterilization effect,fiber bronchoscope structure maintenance and checking,etc.Risks were identified and targeted interventions were implemented.Results Among the 5 pediatric patients who underwent fiber bronchoscopy within 4 days,P.fluorescens was detected from BALF of 3 cases,with a detection rate of 60.0%.The children were 5-8 years old and were admitted to the hospital due to lobar pneumonia.They underwent fiber bronchoscopy from the day of admission to the second day,and bacterial strains were clinically determined to be contaminated strains.Environ-mental sampling showed that the detection rate of P.fluorescens at sampling points such as fiber bronchoscope and enzyme solution storage tank was 15.7%(8/51).After implementing intervention,no target bacteria were detected again,and the difference was statistically significant(P<0.05).From January 1 to May 2,2024,71 BALF from pediatric department were not detected P.fluorescens;From May 3 to 6,among 5 detected BALF,3 were detected P.fluorescens;After intervention(May 16 to December 31),no specimen was detected P.fluorescens.Conclusion This event is a pseudo-outbreak caused by fiber bronchoscope damage as well as improper cleaning and disinfection procedures.Through collaborative investigation and timely intervention by multiple departments,the event was ef-fectively controlled.
4.The inhibitory impact of natural antibacterial biomaterials on Streptococcus mutans and its associated biofilm formation
Xingtao CHANG ; Jiaxin HU ; Jiangling SUN ; Jiqin ZHANG ; Xianrun CHEN ; Guohui BAI ; Yi LUO
STOMATOLOGY 2025;45(3):235-240
In recent years,natural antimicrobial biomaterials have received widespread attention due to their rich sources,broad anti-microbial spectrum,high antimicrobial activity,good biocompatibility,etc.They play an important role in caries prevention and treat-ment by inhibiting the formation of biofilm and removing the formed biofilm.In this paper,we summarize the inhibitory effects of differ-ent natural antimicrobial biomaterials on Streptococcus mutans,the main caries-causing organism,and its biofilm,with a view to provi-ding theoretical references for caries prevention and treatment.
5.Investigation and disposal of a pseudo-outbreak of Pseudomonas fluorescens detected from bronchoalveolar lavage fluid
Feng CHEN ; Dijun LIU ; Renjian HUANG ; Min HOU ; Ziyun HUANG ; Kai-jia WANG ; Xingtao YI
Chinese Journal of Infection Control 2025;24(9):1307-1313
Objective To investigate the causes for the continuous detection of Pseudomonas fluorescens(P.fluo-rescens)from bronchoalveolar lavage fluid(BALF)in pediatric department of a hospital,formulate intervention measures and evaluate its effectiveness,and provide basis for improving the whole process infection control of fiber bronchoscopy.Methods Epidemiological investigation was conducted on three children from whose BALF P.fluorescens were detected in May 3-6,2024.The comprehensive methods were adopted,including case revie-wing,on-site process tracking,environmental hygiene monitoring,laboratory testing on disinfectant sterilization effect,fiber bronchoscope structure maintenance and checking,etc.Risks were identified and targeted interventions were implemented.Results Among the 5 pediatric patients who underwent fiber bronchoscopy within 4 days,P.fluorescens was detected from BALF of 3 cases,with a detection rate of 60.0%.The children were 5-8 years old and were admitted to the hospital due to lobar pneumonia.They underwent fiber bronchoscopy from the day of admission to the second day,and bacterial strains were clinically determined to be contaminated strains.Environ-mental sampling showed that the detection rate of P.fluorescens at sampling points such as fiber bronchoscope and enzyme solution storage tank was 15.7%(8/51).After implementing intervention,no target bacteria were detected again,and the difference was statistically significant(P<0.05).From January 1 to May 2,2024,71 BALF from pediatric department were not detected P.fluorescens;From May 3 to 6,among 5 detected BALF,3 were detected P.fluorescens;After intervention(May 16 to December 31),no specimen was detected P.fluorescens.Conclusion This event is a pseudo-outbreak caused by fiber bronchoscope damage as well as improper cleaning and disinfection procedures.Through collaborative investigation and timely intervention by multiple departments,the event was ef-fectively controlled.
6.The inhibitory impact of natural antibacterial biomaterials on Streptococcus mutans and its associated biofilm formation
Xingtao CHANG ; Jiaxin HU ; Jiangling SUN ; Jiqin ZHANG ; Xianrun CHEN ; Guohui BAI ; Yi LUO
STOMATOLOGY 2025;45(3):235-240
In recent years,natural antimicrobial biomaterials have received widespread attention due to their rich sources,broad anti-microbial spectrum,high antimicrobial activity,good biocompatibility,etc.They play an important role in caries prevention and treat-ment by inhibiting the formation of biofilm and removing the formed biofilm.In this paper,we summarize the inhibitory effects of differ-ent natural antimicrobial biomaterials on Streptococcus mutans,the main caries-causing organism,and its biofilm,with a view to provi-ding theoretical references for caries prevention and treatment.
7.Characteristics of pathological changes of the sclera in high myopia and rela-ted regulatory molecules
Dongmei YANG ; Gang LIANG ; Jun LI ; Jing ZHAO ; Zhi CHEN ; Xingtao ZHOU
Recent Advances in Ophthalmology 2025;45(1):55-59
High myopia is a refractive abnormality characterized by excessive elongation of the eye axis.The sclera,as an important part of the eye axis regulation,plays a key role in the occurrence and development of high myopia.In this pa-per,based on the domestic and international articles,the pathological changes and related regulatory molecules of the scle-ra in high myopia were systematically summarized from the features of scleral lesions in high myopia and the gene regula-tion and signaling pathways affecting the ultrastructure and mechanical properties of the sclera,thus providing a theoretical basis for the study of the pathological mechanism of high myopia.
8.Focusing on preoperative evaluation for cataractous eyes after implantable collamer lens
Xiaoying WANG ; Xingtao ZHOU ; Xiangjia ZHU ; Yongxiang JIANG ; Xun CHEN
Chinese Journal of Experimental Ophthalmology 2024;42(3):219-223
With increasing age, more and more patients with posterior chamber intraocular lens (ICL) implantation are facing the threat of cataracts to their visual acuity.When examining the eyes of cataract patients after ICL surgery, attention should be paid to whether the density of corneal endothelial cells is greater than 2 000 cells/mm 2, the state of the anterior chamber angle, and whether there are fundus abnormalities such as retinal detachment and choroidal neovascularization.When conducting eye biometry measurement, attention should be paid to the measurement starting and ending lines of anterior chamber depth and lens thickness.If patients undergo ICL combined with corneal refractive surgery, they should be examined with two or more devices to obtain corneal refractive power according to the examination requirements after corneal laser vision correction.When selecting the type of intraocular lens, consideration should be given to the histological characteristics of high myopia.Compared to C- and L- loops, plate-haptic is relatively more stable in patients with high myopia accompanied by large capsules and larger diameters of continuous curvilinear capsulorhexis.Kane, Barrett Universal Ⅱ, Olsen, Hill-RBF formulas for calculating the refractive power of intraocular lenses are more accurate in people with long axial length.It is recommended to perform ICL removal simultaneously with phacoemulsification and intraocular lens implantation, preferably with a surgical incision greater than 2.6 mm.Femtosecond laser assisted cataract extraction surgery, although superior to traditional phacoemulsification in reducing corneal endothelial cell loss, reducing corneal edema, and high-quality capsulorhexis, can cause incomplete capsulorhexis and fragmentation due to the cavitation bubbles, manual adjustment of location, and the impact of lower vault.It is recommended to use it with caution.Ophthalmologists should fully understand and pay attention to the characteristics and difficulties of cataract surgery after ICL surgery, communicate fully with patients, and make personalized surgery to achieve better visual outcomes.
9.Comparative studies on the material performances of natural bone-like apatite from different bone sources.
Xiaoxia FAN ; Haohao REN ; Shutian CHEN ; Guangni WANG ; Tianyu DENG ; Xingtao CHEN ; Yonggang YAN
Journal of Biomedical Engineering 2014;31(2):352-356
The compressive strength of the original bone tissue was tested, based on the raw human thigh bone, bovine bone, pig bone and goat bone. The four different bone-like apatites were prepared by calcining the raw bones at 800 degrees C for 8 hours to remove organic components. The comparison of composition and structure of bone-like apatite from different bone sources was carried out with a composition and structure test. The results indicated that the compressive strength of goat bone was similar to that of human thigh bone, reached (135.00 +/- 7.84) MPa; Infrared spectrum (IR), X-ray diffraction (XRD) analysis results showed that the bone-like apatite from goat bone was much closer to the structure and phase composition of bone-like apatite of human bones. Inductively Coupled Plasma (ICP) test results showed that the content of trace elements of bone-like apatite from goat bone was closer to that of apatite of human bone. Energy Dispersive Spectrometer (EDS) results showed that the Ca/P value of bone-like apatite from goat bone was also close to that of human bone, ranged to 1.73 +/- 0.033. Scanning electron microscopy (SEM) patterns indicated that the macrographs of the apatite from human bone and that of goat bone were much similar to each other. Considering all the results above, it could be concluded that the goat bone-like apatite is much similar to that of human bone. It can be used as a potential natural bioceramic material in terms of material properties.
Animals
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Apatites
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chemistry
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Biomechanical Phenomena
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Bone Substitutes
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chemistry
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Bone and Bones
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physiology
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Cattle
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Compressive Strength
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Goats
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Humans
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Microscopy, Electron, Scanning
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Swine
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X-Ray Diffraction
10.Clinical analysis of systemic sclerosis patients with pulmonary arterial hypertension
Qi LIN ; Xingtao HUANG ; Peiying ZENG ; Lu ZHANG ; Cheng CHEN ; Xiaoyan LU
Clinical Medicine of China 2014;(6):602-605
Objective To investigate the clinical features of systemic sclerosis( SSc)patients with pulmonary hypertension(PAH)ane its treatment approach ane prognosis. Methods The clinical information of 16 SSc patients with PAH(PAH group)were recoreee. Seventy-four SSc without PAH were servee as no-PAH group. Patients in PAH group were given the basic therapy inclueing oxygen therapy,anticoagulants,careiac, eiuretic,anti-rheumatic,pulmonary vasoeilator therapy. Results The rate of antinuclear antiboey in PAH ane non-PAH group were 87. 5%(14 / 16)ane 75. 7%(56 / 74),ane the eifference was statistically significant(P= 0. 508). Serum albumin,erythrocyte seeimentation rate at 1 h in PAH group were(32. 6 ± 4. 6)g/ L ane (48. 4 ± 29. 4)mm/ 1 h. The rate of acral lesion proteinuria,hematuria,ECG abnormal rate were 62. 5%(10 / 16),62. 5%(10 / 16),43. 8%(7 / 16),62. 5%(10 / 16)respectively in PAH group. Serum albumin, erythrocyte seeimentation rate at 1 h in PAH group were(35. 6 ± 5. 0)g/ L ane(31. 3 ± 26. 3)mm/ 1 h in non-PAH group. The rate of acral lesions,proteinuria,hematuria,ECG abnormal rate were 31. 1%(23 / 74),27. 0%(20 / 74),12. 2%(9 / 74),9. 5%( 7 / 74 ) respectively in non-PAH group. The eifferences were significant between in terms of all above ineices(P = 0. 033,0. 041,0. 018,0. 006,0. 003,0. 000). During follow-up,the eisease was in stable in 74 case of non-PAH. Among 16 case with PAH,1 mile case was lost,1 case with severe PAH eiee of severe pneumonia,pulmonary hypertension,right ventricular failure,respiratory failure,3 mile patient with PAH were with eevelopment of primary eisease ane the rest 11 cases of PAH patients were with lower interstitial lung eisease than that of the previous eetectee by chest HRCT. Oppler echocareiography measurement of pulmonary artery systolic pressure was(48. 9 ± 2. 4)mmHg before treatment ane then reeucee to(31. 5 ± 4. 5)mmHg in rest 11 cases(t = 22. 27;P = 0. 001)measuree by Doppler echocareiography. Careiac function was improvee euring followee up ane no other aeverse reactions were seen. Conclusion SSc patients merge multiple PAH show it associate with other organ eamage,ane has a poor prognosis. Early careiac Doppler ultrasoune shoule be performee in oreer to get early eiagnosis ane treatment. Treatment approaches shoule be targetee at the primary eisease ane incentives such as pulmonary besiee oxygen therapy,eiuretics,careiac ane anticoagulant erugs in oreer to improve prognosis.

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