Journal of General and Applied Microbiology最新文献_第3页

Systematic promoter design for plasmid-encoded S-adenosylmethionine sensing systems. 质粒编码的 S-腺苷蛋氨酸传感系统的系统性启动子设计。

IF 0.8 4区生物学

Journal of General and Applied Microbiology Pub Date : 2024-07-20 Epub Date: 2024-01-29 DOI: 10.2323/jgam.2024.01.002

Taro Watanabe, Yuki Kimura, Daisuke Umeno

{"title":"Systematic promoter design for plasmid-encoded S-adenosylmethionine sensing systems.","authors":"Taro Watanabe, Yuki Kimura, Daisuke Umeno","doi":"10.2323/jgam.2024.01.002","DOIUrl":"10.2323/jgam.2024.01.002","url":null,"abstract":"S-adenosylmethionine (SAM) is an important biomolecule that mainly acts as a methyl donor and plays many roles in a variety of biological functions. SAM is also required for the biosynthesis of valuable methylated compounds, but its supply is a bottleneck for these biosynthetic pathways. To overcome this bottleneck and to reconfigure SAM homeostasis, a high-throughput sensing system for changes in intracellular SAM availability is required. We constructed a plasmid that can detect the factors that can alter SAM availability using minimal components. It does so by placing a fluorescent protein under a promoter controlled by endogenous MetJ, a transcription factor that represses its own regulons upon binding with SAM. Next, to validate SAM-responsive behavior, we systematically reconstructed 10 synthetic promoters with different positions and with different number of metbox sites. We found that a position between the -35 box and the -10 box was the most effective for repression and that this setup was suitable for detecting the genetic or environmental factors that can deplete and recover the intracellular SAM availability. Overall, the response patterns of the synthetic MetJ-regulated promoters characterized in this study may be useful for the development of better SAM biosensing systems.","PeriodicalId":15842,"journal":{"name":"Journal of General and Applied Microbiology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139570013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Identification of the Csr global regulatory system mediated by small RNA decay in Aeromonas salmonicida. 鉴定沙门氏菌中由小 RNA 降解介导的 Csr 全局调控系统。

IF 0.8 4区生物学

Journal of General and Applied Microbiology Pub Date : 2024-07-20 Epub Date: 2024-01-18 DOI: 10.2323/jgam.2023.12.004

Olga Gladyshchuk, Masaki Yoshida, Koume Togashi, Hayuki Sugimoto, Kazushi Suzuki

{"title":"Identification of the Csr global regulatory system mediated by small RNA decay in Aeromonas salmonicida.","authors":"Olga Gladyshchuk, Masaki Yoshida, Koume Togashi, Hayuki Sugimoto, Kazushi Suzuki","doi":"10.2323/jgam.2023.12.004","DOIUrl":"10.2323/jgam.2023.12.004","url":null,"abstract":"We investigated the presence and functionality of the carbon storage regulator (Csr) system in Aeromonas salmonicida SWSY-1.411. CsrA, an RNA-binding protein, shared 89% amino acid sequence identity with Escherichia coli CsrA. CsrB/C sRNAs exhibited a typical stem-loop structure, with more GGA motifs, which bind CsrA, than E. coli. CsrD had limited sequence identity with E. coli CsrD; however, it contained the conserved GGDEF and EAL domains. Functional analysis in E. coli demonstrated that the Csr system of A. salmonicida influences glycogen biosynthesis, biofilm formation, motility, and stability of both CsrB and CsrC sRNAs. These findings suggest that in A. salmonicida, the Csr system affects phenotypes like its E. coli counterpart. In A. salmonicida, defects in csr homologs affected biofilm formation, motility, and chitinase production. However, glycogen accumulation and protease production were unaffected. The expression of flagellar-related genes and chitinase genes was suppressed in the csrA-deficient A. salmonicida. Northern blot analysis indicated the stabilization of CsrB and CsrC in the csrD-deficient A. salmonicida. Similar to that in E. coli, the Csr system in A. salmonicida comprises the RNA-binding protein CsrA, the sRNAs CsrB and CsrC, and the sRNA decay factor CsrD. This study underscores the conservation and functionality of the Csr system and raises questions about its regulatory targets and mechanisms in A. salmonicida.","PeriodicalId":15842,"journal":{"name":"Journal of General and Applied Microbiology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139485641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Biodegradation of phthalic acid esters (PAEs) by Janthinobacterium sp. strain E1 under stress conditions. Janthinobacterium sp. 菌株 E1 在压力条件下对邻苯二甲酸酯 (PAE) 的生物降解。

IF 0.8 4区生物学

Journal of General and Applied Microbiology Pub Date : 2024-07-20 Epub Date: 2024-01-15 DOI: 10.2323/jgam.2023.12.002

Kailu Zhang, Hui Zhou, Juntao Ke, Hongli Feng, Cunlong Lu, Shaoxing Chen, Aimin Liu

{"title":"Biodegradation of phthalic acid esters (PAEs) by Janthinobacterium sp. strain E1 under stress conditions.","authors":"Kailu Zhang, Hui Zhou, Juntao Ke, Hongli Feng, Cunlong Lu, Shaoxing Chen, Aimin Liu","doi":"10.2323/jgam.2023.12.002","DOIUrl":"10.2323/jgam.2023.12.002","url":null,"abstract":"Phthalates esters (PAEs) are a kind of polymeric material additives widely been added into plastics to improve products' flexibility. It can easily cause environmental pollution which are hazards to public health. In this study, we isolated an efficient PAEs degrading strain, Janthinobacterium sp. E1, and determined its degradation effect of di-2-ethylhexyl phthalate (DEHP) under stress conditions. Strain E1 showed an obvious advantage in pollutants degradation under various environmental stress conditions. Degradation halo clearly occurred around the colony of strain E1 on agar plate supplemented with triglyceride. Strain E1's esterase is a constitutively expressed intracellular enzyme. The esterase purified from strain E1 showed a higher catalytic effect on short-chain PAEs than long-chain PAEs. The input of DEHP, DBP (dibutyl phthalate) and DMP (dimethyl phthalate) into the tested soil did not change the species composition of soil prokaryotic community, but altered the dominant species in specific environmental conditions. And the community diversity and richness decreased to a certain extent. However, the diversity and richness of the microbial community were improved after the contaminated soil was treated with the strain E1. Our results also suggested that strain E1 exhibited a tremendous potential in environmental bioremediation in the real environment, which provides a new insight into the elimination of the pollutants contamination in the urban environment.","PeriodicalId":15842,"journal":{"name":"Journal of General and Applied Microbiology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139466704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Zn solubilizing bacteria (ZSB) mitigate toxicity of silver and Titanium dioxide nanoparticles in Mung bean by increasing photosynthetic pigment content. 锌溶解菌（ZSB）通过增加光合色素含量来减轻纳米银和二氧化钛对绿豆的毒性。

IF 0.8 4区生物学

Journal of General and Applied Microbiology Pub Date : 2024-06-27 DOI: 10.2323/jgam.2024.05.005

Mahvash Haroon, Shams Tabrez Khan, Abdul Malik

{"title":"Zn solubilizing bacteria (ZSB) mitigate toxicity of silver and Titanium dioxide nanoparticles in Mung bean by increasing photosynthetic pigment content.","authors":"Mahvash Haroon, Shams Tabrez Khan, Abdul Malik","doi":"10.2323/jgam.2024.05.005","DOIUrl":"https://doi.org/10.2323/jgam.2024.05.005","url":null,"abstract":"Zn-deficiency, a global health challenge affects one-third of the world population. Zn-biofertilizer offer an efficient and cost-effective remedy. As Zn-biofertilizer can improve plant growth and grain's Zn-content ensuring improved dietary Zn-supply. This study sought to understand how silver and TiO2 nanoparticles in the rhizosphere affect the activity of Zn-solubilization bacteria (ZSB) and plant growth. Two ZSB strains Bacillus sp. D-7 and Pseudomonas sp. D-117 with excellent Zn-solubilization efficiency of 254 and 260%, respectively were isolated and characterized using polyphasic characterization including 16S rRNA gene sequencing to formulate an effective Zn-biofertilizer. The plant growth promoting activity of this biofertilizer in Mung bean was checked in the presence and absence of various doses of TiO2 and Ag-NPs and was compared with plant grown without biofertilizer. The change in rate of seed germination, vegetative growth (shoot and root length, fresh and dry weight), photosynthetic pigment and Zn-content was checked. Lower doses of nanomaterials (50 and 100 mg kg⁻¹ soil) slightly promoted the plant growth compared to control. While, higher doses (200 and 400 mg kg⁻¹ soil) inhibited the growth. A maximum decrease of shoot length, root length, fresh-weight, and dry-weight of 57.1, 53.9, 53.1, and 10.4% respectively was observed with 400 mg kg⁻¹ of Ag-NPs. However, in the presence of ZSB, the decrease at the same Ag-NP concentration was 41.6, 31.5, 27.4, and 6.6, respectively. These results strongly suggest that Zn-solubilizing bacteria improve resilience to nanoparticles toxicity and helps in Zn fortification in Mung bean even under nanomaterial stress.","PeriodicalId":15842,"journal":{"name":"Journal of General and Applied Microbiology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141457388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Development of conjugation-mediated versatile site-specific single-copy luciferase fusion system. 偶联介导的多功能位点特异性单拷贝萤光素酶融合系统的开发。

IF 1.2 4区生物学

Journal of General and Applied Microbiology Pub Date : 2024-05-02 Epub Date: 2023-11-07 DOI: 10.2323/jgam.2023.10.001

Akinori Kato

{"title":"Development of conjugation-mediated versatile site-specific single-copy luciferase fusion system.","authors":"Akinori Kato","doi":"10.2323/jgam.2023.10.001","DOIUrl":"10.2323/jgam.2023.10.001","url":null,"abstract":"There are a number of reporter systems that are useful for gene expression analysis in bacteria. However, at least in Salmonella, a versatile and simple luciferase reporter system that can be integrated precisely behind a promoter or gene of interest on a chromosome is not currently available. The luciferase operon luxCDABE from Photorhabdus luminescens has several advantages, including brightness, wide linear range, absence in most bacteria, stability at high temperature, and no substrate addition required for the assay. Here, a conjugation-mediated site-specific single-copy luciferase fusion system is developed. A reporter plasmid containing the conditional replication origin R6Kgγ, FRT-luxCDABE, and KmR marker was designed to be incorporated into the FRT site behind the promoter or gene of interest on the chromosome in cells expressing FLP. However, when this reporter plasmid was electroporated directly into such a S. enterica strain, no colonies appeared, likely due to the low transformation efficiency of this relatively large plasmid DNA. Meanwhile, the same reporter plasmid was successfully introduced and launched as an insert of an FRT-containing conjugative transfer plasmid from a mating E. coli strain to the same recipient S. enterica strain, as well as Citrobacter koseri. RcsB-dependent inducible luminescence from the constructed wzc-luxCDABE strains was confirmed. This system is feasible for detecting very low levels of transcription, even in Gram-negative bacterial species that are relatively difficult to genetically manipulate.","PeriodicalId":15842,"journal":{"name":"Journal of General and Applied Microbiology","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71521730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Heterologous expression and characterization of an M4 family extracellular metalloprotease for detergent application. 用于洗涤剂应用的M4家族胞外金属蛋白酶的异源表达和表征。

IF 1.2 4区生物学

Journal of General and Applied Microbiology Pub Date : 2024-05-02 Epub Date: 2023-10-26 DOI: 10.2323/jgam.2023.09.002

Man Hao, Chaoshuo Shi, Weifeng Gong, Jia Liu, Xiangxin Meng, Fufeng Liu, Fuping Lu, Huitu Zhang

{"title":"Heterologous expression and characterization of an M4 family extracellular metalloprotease for detergent application.","authors":"Man Hao, Chaoshuo Shi, Weifeng Gong, Jia Liu, Xiangxin Meng, Fufeng Liu, Fuping Lu, Huitu Zhang","doi":"10.2323/jgam.2023.09.002","DOIUrl":"10.2323/jgam.2023.09.002","url":null,"abstract":"Proteolytic enzymes stand out as the most widely employed category utilized in manufacturing industry. A new protease was separated from Planococcus sp.11815 strain and named as nprS-15615 in this research. The gene of this protease has not been reported, and its enzymatic properties have been studied for the first time. To enhance enzyme production, the Planococcus sp. protease gene was expressed in Bacillus licheniformis 2709. The expression level of nprS-15615 was observed under the control of regulatory elements PaprE. nprS-15615 protease activity reached 1186.24±32.87 U/mL after 48 hours of cultivation in shake flasks which was nearly four times the output of the original bacteria (291.38±25.73U/mL). The optimum temperature and pH of the recombinant protease were 30 ℃ and 8.0, respectively.The enzyme exhibited the highest capacity for hydrolyzing casein and demonstrated resilience towards a NaCl concentration of 10.0% (wt/v). Furthermore, in the presence of 0.5% surfactants, the recombinant protease activity can maintain above 75%, and with the existence of 0.5% liquid detergents, there was basically no loss of enzyme activity which indicated that nprS-15615 had good compatibility with surfactants and liquid detergents. In addition, npS-15615 performed well in the washing experiment, and the washing effect at 20 ℃ can be significantly improved by adding crude enzyme solution in the washing process.","PeriodicalId":15842,"journal":{"name":"Journal of General and Applied Microbiology","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50161838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Metarhizium robertsii COH1 functionally complements Schizosaccharomyces pombe Ecl family proteins. 罗伯特绿僵菌COH1在功能上与pombe裂殖酵母Ecl家族蛋白互补。

IF 1.2 4区生物学

Journal of General and Applied Microbiology Pub Date : 2024-05-02 Epub Date: 2023-10-06 DOI: 10.2323/jgam.2023.09.001

Hokuto Ohtsuka, Sawa Kawai, Yoko Otsubo, Takafumi Shimasaki, Akira Yamashita, Hirofumi Aiba

引用次数: 0

Purification and characterization of moderately thermostable raw-starch digesting α-amylase from endophytic Streptomyces mobaraensis DB13 associated with Costus speciosus. 从内生链霉菌（Streptomyces mobaraensis DB13）中纯化和表征与木薯（Costus speciosus）相关的中等恒温生淀粉消化α-淀粉酶。

IF 1.2 4区生物学

Journal of General and Applied Microbiology Pub Date : 2024-05-02 Epub Date: 2023-08-25 DOI: 10.2323/jgam.2023.08.001

Dina Barman, Mamtaj S Dkhar

{"title":"Purification and characterization of moderately thermostable raw-starch digesting α-amylase from endophytic Streptomyces mobaraensis DB13 associated with Costus speciosus.","authors":"Dina Barman, Mamtaj S Dkhar","doi":"10.2323/jgam.2023.08.001","DOIUrl":"10.2323/jgam.2023.08.001","url":null,"abstract":"Endophytic actinobacteria are known to produce various enzymes with potential industrial applications. Alpha-amylase is an important class of industrial enzyme with a multi-dimensional utility. The present experiment was designed to characterize a moderately thermostable α-amylase producing endophytic Streptomyces mobaraensis DB13 isolated from Costus speciosus (J. Koenig) Sm. The enzyme was purified using 60% ammonium sulphate precipitation, dialysis, and Sephadex G-100 column chromatography. Based on 12% SDS-PAGE, the molecular weight of the purified α-amylase was estimated to be 55 kDa. The maximum α-amylase activity was achieved at pH 7.0, 50°C and it retained 80% of its activity at both pH 7.0 and 8.0 after incubation for 2 h. The α-mylase activity is strongly enhanced by Ca2+, Mg2+, and inhibited by Ba2+. The activity remains stable in the presence of Tween-80, SDS, PMSF, and Triton X-100; however, β-mercaptoethanol, EDTA, and H2O2 reduced the activity. The kinetic parameters Km and Vmax values for this α-amylase were calculated as 2.53 mM and 29.42 U/mL respectively. The α-amylase had the ability to digest various raw starches at a concentration of 10 mg/mL at pH 7.0, 50°C, where maize and rice are the preferred substrates. The digestion starts after 4 h of incubation, which reaches maximum after 48 h of incubation. These results suggest that S. mobaraensis DB13 is a potential source of moderately thermostable α-amylase enzyme, that effciently hydrolyzes raw starch. It suggesting that this α-amylase is a promising candidate to be use for industrial purposes.","PeriodicalId":15842,"journal":{"name":"Journal of General and Applied Microbiology","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10074957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Inhibition and biocontrol potential of Ochrobactrum pseudogrignonense NC1 against four Phytophthora species. 伪绿僵杆菌NC1对4种疫霉的抑制作用及其生物防治潜力。

IF 1.2 4区生物学

Journal of General and Applied Microbiology Pub Date : 2024-05-02 Epub Date: 2023-11-21 DOI: 10.2323/jgam.2023.11.001

Jinming Liu, Shiyu Zhang, Haikun Ma, Jun Huang, Meichun Xiang, Xingzhong Liu

{"title":"Inhibition and biocontrol potential of Ochrobactrum pseudogrignonense NC1 against four Phytophthora species.","authors":"Jinming Liu, Shiyu Zhang, Haikun Ma, Jun Huang, Meichun Xiang, Xingzhong Liu","doi":"10.2323/jgam.2023.11.001","DOIUrl":"10.2323/jgam.2023.11.001","url":null,"abstract":"Phytophthora species are highly destructive soilborne oomycetes pathogens that spread through infested soil and water. Ochrobactrum pseudogrignonense NC1 has been shown to inhibit plant parasitic nematodes via volatile organic compounds (VOCs). In this study, we investigated the inhibitory effect of O. pseudogrignonense NC1 against four Phytophthora species on agar plates and in vivo bioassay. We found that NC1 significantly inhibited the mycelial growth and zoospore production of all four species of Phytophthora in a dose-dependent manner. The half maximal inhibitory concentration (IC50) values for inhibition of mycelial growth (or zoospore production) were 26% (14.8%), 18.9% (14.2%), 20.3% (8.3%) and 46.9% (4%) for Phytophthora capsici Leonian, Phytophthora infestans, Phytophthora parasitica var. nicotiana and Phytophthora sojae, respectively. The biocontrol efficiency of NC1 was 46.3% in pepper seedlings against P. capsici, almost 100% in potato tubers against P. infestans, 60% in tomato leave against P. parasitica and 100% in soybean leave against P. sojae, respectively. Our findings suggest that O. pseudogrignonense NC1 has great potential as a biocontrol agent for managing Phytophthora diseases.","PeriodicalId":15842,"journal":{"name":"Journal of General and Applied Microbiology","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138291158","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Gallic acid fermentation by metabolically engineered Escherichia coli producing p-hydroxybenzoate hydroxylase from Hylemonella gracilis NS1. 代谢工程大肠杆菌产生来自 Hylemonella gracilis NS1 的对羟基苯甲酸羟化酶发酵没食子酸。

IF 1.2 4区生物学

Journal of General and Applied Microbiology Pub Date : 2024-05-02 Epub Date: 2023-08-30 DOI: 10.2323/jgam.2023.08.004

Nozomi Katsuki, Shunsuke Masuo, Noriyuki Nukui, Hajime Minakawa, Naoki Takaya

{"title":"Gallic acid fermentation by metabolically engineered Escherichia coli producing p-hydroxybenzoate hydroxylase from Hylemonella gracilis NS1.","authors":"Nozomi Katsuki, Shunsuke Masuo, Noriyuki Nukui, Hajime Minakawa, Naoki Takaya","doi":"10.2323/jgam.2023.08.004","DOIUrl":"10.2323/jgam.2023.08.004","url":null,"abstract":"Plant-derived phenolic gallic acid (GA) is an important raw material for antioxidants and food additives. Efforts to ferment GA using microbial processes have aimed at minimizing production costs and environmental load using enzymes that hydroxylate p-hydroxybenzoate and protocatechuate (PCA). Here, we found a p-hydroxybenzoate hydroxylase (PobA) in the bacterium Hylemonella gracilis NS1 (HgPobA) with 1.5-fold more hydroxylation activity than that from Pseudomonas aeruginosa PAO1 and thus converted PCA to GA more efficiently. The PCA hydroxylation activity of HgPobA was improved by introducing the amino acid substitutions L207V/Y393F or T302A/Y393F. These mutants had 2.9- and 3.7-fold lower Kmapp for PCA than wild-type HgPobA. An Escherichia coli strain that reinforces shikimate pathway metabolism and produces HgPobA when cultured for 60 h generated 0.27 g L-1 of GA. This is the first report of fermenting glucose to generate GA using a natural enzyme from the PobA family. The E. coli strain harboring the HgPobA L207V/Y393F mutant increased GA production to 0.56 g L-1. During the early stages of culture, GA was fermented at a 10-fold higher rate by a strain producing either HgPobA L207V/Y393F or T302A/Y393F compared with wild-type HgPobA, which agreed with the high kcatapp/Kmapp PCA values of this mutant. We enhanced a PobA isozyme and its PCA hydroxylating function to efficiently and cost-effectively ferment GA.","PeriodicalId":15842,"journal":{"name":"Journal of General and Applied Microbiology","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10120794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0