APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
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2024
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IF 3.1
Li Keyan,Deng Fuli,Wang Yonghua,Wang Fanghua
Activation of fatty acids as acyl-adenylates by fatty acid-AMP ligase (FAAL) is a well-established process contributing to the formation of various functional natural products. Enzymatic characterization of FAALs is pivotal for unraveling both the catalytic mechanism and its role in specific biosynthetic pathways. In this study, we recombinantly expressed and characterized a novel FAAL derived from marine Pseudoalteromonas citrea ( Pc FAAL). Pc FAAL was a cold-adapted neutral enzyme, demonstrating optimal activity at 30 °C and pH 7.5. Notably, its specific activity relied on the presence of Mg 2+ ; however, higher concentrations exceeding 10 mM resulted in inhibition of enzyme activity. Various organic solvents, especially water-immiscible organic solvents, demonstrated an activating effect on the activity of Pc FAAL on various fatty acids. The specific activity exhibited a remarkable 50-fold increase under 4% (v/v) n-hexane compared to the aqueous system. Pc FAAL displayed a broad spectrum of fatty acid substrate selectivity, with the highest specific activity for octanoic acid (C8:0), and the catalytic efficiency ( k cat / K m ) for octanoic acid was determined to be 1.8 nM −1 ·min −1 . Furthermore, the enzyme demonstrated biocatalytic promiscuity in producing a class of N-acyl amino acid natural products, as verified by LC-ESI MS. Results indicated that the Pc FAAL exhibits promiscuity towards 10 different kinds of amino acids and further demonstrated their potential value in the biosynthesis of corresponding functional N-acyl amino acids.
研究领域:
海洋微生物学
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酶学
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生物化学
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DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2020
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IF 5.162
Xiaoyi Qu,Bo Ding,Jing Li,Meng Liang,Liqin Du,Yutuo Wei,Ribo Huang,Hao Pang
A novel β-glucosidase gene was isolated from Pseudoalteromonas sp. GXQ-1 and heterologously expressed in Escherichia coli . The activity of the encoded enzyme, PABGL, toward p -nitrophenyl-β-D-glucopyranoside was increased 8.74-fold by the presence of 3 M NaCl relative to the absence of added NaCl. PABGL hydrolyzed a variety of soy isoflavone substrates. For the conversion of daidzin to daidzein, the production rate was 1.44 mM/h. The addition of NaCl enhanced the hydrolytic activity of PABGL toward daidzin and genistein; the maximum activation by NaCl was 3.48- and 6.79-fold, respectively. This is the first report of a halophilic β-glucosidase from Pseudoalteromonas spp., and represents the β-glucosidase with the highest multiple of activation by NaCl. PABGL exhibits strong potential for applications in food processing and industrial production.
研究领域:
生物化学
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酶学
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微生物学
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食品科学
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生物技术
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DOI
PubMed
高影响因子
ENZYME AND MICROBIAL TECHNOLOGY
·
2023
·
IF 3.4
Tao Hong,Liufei Long,Yuyan Sang,Zedong Jiang,Hui Ni,Mingjing Zheng,Lijun Li,Qingbiao Li,Yanbing Zhu
κ-Carrageenase provides an attractive enzymatic approach to preparation of κ-carrageenan oligosaccharides . Pseudoalteromonas tetraodonis κ-carrageenase is active at the alkaline conditions but displays low thermostability . To further improve its enzymatic performance, two mutants of Q42V and I51H exhibiting both improved thermostability and enzyme activity were screened by the PoPMuSiC algorithm. Compared with the wild-type κ-carrageenase (WT), Q42V and I51H increased the enzyme activity by 20.9% and 25.4%, respectively. After treatment at 50 ℃ for 40 min, Q42V and I51H enhanced the residual activity by 31.1% and 25.9%, respectively. The T m values of Q42V, I51H, and WT determined by differential scanning calorimetry were 58.2 ℃, 54.8 ℃, and 51.2 ℃, respectively. Compared with untreated and HCl-treated κ-carrageenans, Q42V-treated κ-carrageenan exhibited higher pancreatic lipase inhibitory activity. Molecular docking analysis indicated that the additional pi-sigma force and hydrophobic interaction in the enzyme-substrate complex could account for the increased catalytic activity of Q42V and I51H, respectively. Molecular dynamics analysis indicated that the improved thermostability of mutants Q42V and I51H could be attributed to the less structural deviation and the flexible changes of enzyme conformation at high temperature. This study provides new insight into κ-carrageenase performance improvement and identifies good candidates for their industrial applications.
研究领域:
酶学
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生物技术
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海洋生物学
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食品科学
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DOI
PubMed
高影响因子
ACS Omega
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2025
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IF 4.3
Songzhi Li,Yang Guo,Hong Jiang,Huan Zhang,Jiayu Li,Yanli Chen,Jie Li,Xiangzhao Mao,Minxiao Wang
Arylsulfatase catalyzes the cleavage of sulfate ester bonds and plays a role in agar desulfation, thereby enhancing agar gel strength and quality. While studying the desulfurization pathway in Pseudoalteromonassp. SR43-6, a sequence encoding a potential arylsulfatase─Pseudoalteromonas Ars (Ps-Ars)─was found. The enzyme, with p-nitrophenyl sulfate as a substrate, exhibited optimal activity at 35 °C and pH 8.0. Its relative activity (206 U/mg) exceeded that of the recently identified arylsulfatases. Four hundred units of the enzyme removed 86.4% of sulfate groups from Gelidium amansii agar in 4 h, whereas 800 U of the enzyme removed 71.3% of sulfate groups from Gracilaria lemaneiformis agar in 8 h. After enzymatic treatment, G. amansii agar gel strength was enhanced by 32%, and a similar improvement was observed in G. lemaneiformis agar gel strength. Enzymatic agar desulfurization offers mild, quality-retaining, and environmentally friendly advantages, augmenting industrial application prospects.
研究领域:
生物化学
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海洋微生物学
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食品科学
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DOI
PubMed
高影响因子
Marine Drugs
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2023
·Vol. 21
·期 2
·133
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IF 5.4
Congling Liu,Gong Chen,Hailian Rao,Xun Xiao,Yidan Chen,Cuiling Wu,Fei Bian,Hailun He
Crude enzymes produced by a marine bacteriumPseudoalteromonassp. JS4-1 were used to hydrolyze phycobiliprotein. Enzymatic productions showed good performance on DPPH radical and hydroxyl radical scavenging activities (45.14 ± 0.43% and 65.11 ± 2.64%, respectively), especially small peptides with MWCO <3 kDa. Small peptides were fractioned to four fractions using size-exclusion chromatography and the second fraction (F2) had the highest activity in hydroxyl radical scavenging ability (62.61 ± 5.80%). The fraction F1 and F2 both exhibited good antioxidant activities in oxidative stress models in HUVECs and HaCaT cells. Among them, F2 could upregulate the activities of SOD and GSH-Px and reduce the lipid peroxidation degree to scavenge the ROS to protectCaenorhabditis elegansunder adversity. Then, 25 peptides total were identified from F2 by LC-MS/MS, and the peptide with the new sequence of INSSDVQGKY as the most significant component was synthetized and the ORAC assay and cellular ROS scavenging assay both illustrated its excellent antioxidant property.Keywords:phycobiliprotein;antioxidant peptide;bacterial extracellular protease;enzymatic hydrolyzation;C. elegans
研究领域:
生物化学
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分子生物学
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海洋生物学
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DOI
PubMed
高影响因子
ENVIRONMENTAL MICROBIOLOGY
·
2015
·Vol. 17
·期 10
·3795-3806
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IF 6.201
Zi-Hao Mi,Zi-Chao Yu,Hai-Nan Su,Lei Wang,Xiu-Lan Chen,Xiuhua Pang,Qi-Long Qin,Bin-Bin Xie,Xi-Ying Zhang,Bai-Cheng Zhou,Yu-Zhong Zhang
Summary Although bacteriobenthos play a major role in the degradation of particulate organic matter in marine sediment, knowledge of the sediment-adapted lifestyles of bacteriobenthos is still scarce. Here, the particle-associated, swimming and swarming lifestyles of the benthonic bacterium P seudoalteromonas sp. SM9913 (SM9913) were illustrated. SM9913 had a clay particle-associated lifestyle, and its exopolysaccharide played an important role in this lifestyle. SM9913 also had swimming and swarming motilities, indicating that it may have swimming and swarming lifestyles in the sediment. The lateral flagella were responsible for the swarming motility, and the polar flagella were responsible for the swimming motility. Iron limitation was an indispensable inductive signal of the swarming motility. An analysis of the motilities of SM9913 and its mutants in clay demonstrated that SM9913 moved in clay by both swimming and swarming motilities. Genomic analysis suggests that having two flagella systems is most likely a common adaptation of some bacteriobenthos to the sediment environment. Our results reveal the lifestyles of benthonic SM9913, providing a better understanding of the environmental adaptation of benthonic bacteria.
研究领域:
微生物学
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海洋生物学
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基因组学
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环境科学
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DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2023
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IF 5.2
Jinyan Tan,Jinsong Wang,Jinlong Yang,Jie Wang,Taijiang Gui,Limin Wu,Shuxue Zhou
The current zwitterionic antifouling (AF) coatings generally have limited broad-spectrum AF ability, poor compatibility with coating matrixes and weak mechanical properties due to high water adsorption. In this work, we tried to incorporate zwitterionic component, namely, ( N -methoxyacylethyl)-3-aminopropyltriethoxysilane (MAPS) and ZnO nanoparticles into a moisture-curable polyacrylate (MCP) to fabricate marine AF coatings. AF behaviors were examined by laboratory and field assays towards different target foulants. Laboratory anti-protein ability towards bovine serum albumin promoted with the increase of MAPS and/or ZnO contents, verifying their synergistic AF effect towards the earliest pollutant in biofouling process. Laboratory AF test towards bacterium Pseudoalteromonas marina and diatom Cylindrotheca closterium also exhibited the synergistic AF effect between zwitterions and ZnO nanoparticles, however, depending on their concentrations. Under the highest contents of MAPS ( i.e., 30 %) and ZnO nanoparticles ( i.e., 50 %), the coatings showed the best laboratory AF properties, with the antibacterial rate, sterilization rate and anti-diatom rate of 86.7 %, 71.8 % and 87.6 %, respectively. As for the marine field AF performance, the ZnO nanoparticles content had a significant effect on improving the field antibacterial ability, while the effect of MAPS was not obvious. But for the field anti-diatom assay, MAPS and ZnO nanoparticles depicted synergistic effect on diatom resistance. After field exposure for 52 d, the coatings with 30 % MAPS and 50 % ZnO nanoparticles revealed the best comprehensive AF performance, i.e., 82.4 %, 95.0 % and 95.5 % reductions towards bacteria, diatoms and mussels, respectively, and moreover, maintained pencil hardness of 2 H after immersed in ASW for 9 months. Besides, the coatings were capable of restoring their original oleophobicity and AF capability after mechanical abrasion.
研究领域:
材料科学
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海洋生物学
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涂料技术
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纳米技术
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产品关联
DOI
高影响因子
FOOD RESEARCH INTERNATIONAL
·
2026
·
IF 8.8
Du Qi,Yu Mijia,Ruyi Dong,Daodong Pan,Shanshan Shui,Bin Zhang
Crabs are highly susceptible to quality deterioration during chilled storage, primarily due to protein degradation and flavor changes. To systematically evaluate this spoilage process, we stored swimming crab at 4 °C for 5 d and conducted a comprehensive analysis. This included measuring sensory attributes and key physicochemical indices, such as centrifugal loss and trimethylamine (TMA) content, as well as the sulfhydryl content of myofibrillar protein. We also profiled free amino acids (FAAs) and volatile organic compounds (VOCs) and characterized the microbial community composition. The sensory score dropped below the acceptable threshold of 6, centrifugal loss increased by more than 200%, while TMA content exceeded 8 mg/100 g after chilled storage. Additionally, the sulfhydryl content of myofibrillar protein decreased significantly, by 68% in the pincer muscle and 92% in the cephalothorax muscle; the total variable count in both regions increased. Shifts in FAA profiles and an increase in undesirable VOCs were documented. Furthermore, microbial analysis demonstrated that bacterial community succession culminated in dominance by the genus Pseudoalteromonas , which also showed significant positive correlations with VOCs (e.g., 1-octen-3-one and 1-penten-3-one), FAAs (e.g., Met and Tyr), and the deterioration of physicochemical characteristics (e.g., centrifuge loss and TMA content). In conclusion, this integrated study provides a potential scientific foundation for developing targeted strategies to preserve quality and extend shelf life.
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PubMed
高影响因子
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