This study evaluated the ability of a dextranase from marine bacterium Catenovulum sp. (Cadex) to impede formation Streptococcus mutans biofilms, primary pathogen dental caries, one most common human infectious diseases. Cadex was purified 29.6-fold and had specific activity 2309 U/mg protein molecular weight 75 kDa. showed maximum at pH 8.0 40 °C stable temperatures under 30 ranging 5.0 11.0. A metal ion chemical dependency that Mn2+ Sr2+ exerted positive effects on Cadex, whereas Cu2+,...

Vibrio anguillarum is a bacterial pathogen that causes serious damage to aquatic fish, and its rapid detection prevention are critical. DNAzymes DNA-based catalysts with excellent stability. In this study, in vitro selection of was performed using the crude extracellular matrix (CEM) V. Anguillarum as target. Different from previous selections targeting CEM, work used an unmodified DNA library, allowing easier adoption technology. After seven rounds selection, DNAzyme named VAE-2 high...

A four-week feeding trial, followed by a challenge test, was conducted to evaluate the effects of Lactococcus lactis and astaxanthin on growth performance, digestive ability, antioxidant capacity, immunity, disease resistance Litopenaeus vannamei against Vibrio alginolyticus. Specifically, shrimp were randomly allocated into 12 tanks (100 per tank), divided 4 groups with 3 replicates. Shrimp fed either control (CK) or three other treatment diets supplementing L. at 1 × 108 CFU g−1 diet (L),...

Abstract A feasible and umpolung strategy for the synthesis of structurally diverse β ‐amino ketones has been achieved through TEMPO mediated C−N coupling cyclopropanols with nitrogen nucleophiles. Mechanism studies indicated that in situ generated enones derived from are key intermediates play multiple roles, including radical initiator, trapping reagent, a porter ‐hydrogen an base. This protocol features broad substrate scope, good scalability to excellent yields provides alternative...

Lactiplantibacillus pentosus 292 is a lactic acid bacterium (LAB) with significant probiotic potential, but large-scale production often limited by high costs and preservation challenges. This study aimed to develop cost-effective medium enhance establish feasible strategy support the strain's application. A low-cost containing glucose, yeast powder, K₂HPO₄, Tween-80 was formulated, enabling achieve yield of 16.24 g/L, representing an 83.48% increase compared traditional MRS medium....

Recently a series of triterpenoids were isolated from ganoderma spores and have drawn the attention chemists pharmacists. The aim this review is to summarize their bioactivities spores. chemical biological literatures dealing with structural analysis bioactivity assay selected. Triterpenoids showed significantly anti-HIV-1 protease, anti-tumor, anti-complement activities. are main active constituents show various for its medicinal use. In addition, activities still need further assessment...

The crystal structure of Dextranase from the marine bacterium Arthrobacter oxidans KQ11 (Aodex) was determined at a resolution 1.4 Å. conserved Aodex fragment (Ala52–Thr638) consisted an N-terminal domain N and C-terminal C. identified as β-sandwich, connected to right-handed parallel β-helix C-terminus. Sequence comparisons, cavity regions, key residues catalytic analysis all suggested that inverting enzyme, acid base were Asp439 Asp420, respectively. Asp440 not general in domain, Asp396...

Abstract Background Minqin is suffering from a serious desertification, whereas the knowledge about its bacterial community limited. Herein, based on Nitraria tangutorum and Haloxylon ammodendron Minqin, diversities in fixed sandy land, semi-fixed land shifting were investigated by combining with culture-dependent culture-independent methods. Results stressed high salinity poor nutrition an oligotrophic environment. Bacterial was shaped primarily presence of host plants, type plant had no...

Aquaculture is suffering from long-term water eutrophication in intensive models, whereas the knowledge of multi-strain/specie for improving quality extremely limited. Herein, we aimed to develop multi-strain tropical Bacillus spp. as a potential probiotic biocontrol agent large-scale enhancement mariculture quality. Given practical application, optimum (B. flexus QG-3, B. NS-4, and licheniformis XCG-6 with proportion 5: 4) was screened obtained, which effectively improved by removing...

Protease-producing bacteria play vital roles in degrading organic matter of aquaculture system, while the knowledge diversity and bacterial community structure protease-producing is limited this especially tropical region. Herein, 1,179 cultivable strains that belonged to Actinobacteria, Firmicutes, Proteobacteria were isolated from systems, which most abundant genus was Bacillus , followed by Vibrio . The relative abundance sediment generally higher than those water. Twenty-one genera 16...

Abstract Vibrio vulnificus is an important bacterial pathogen that causes serious infections in fish and also highly pathogenic to humans. Many effective detection methods targeting this have previously been designed, but many of these are time‐consuming, complicated expensive. Thus, approaches cannot be widely used by small aqacultural concerns. Although DNA aptamers detect bacteria, not applied marine including V. . Therefore, we developed a specific aptamer for using systematic evolution...

A GH49 dextranase gene DexKQ was cloned from marine bacteria Arthrobacter oxydans KQ11. It recombinantly expressed using an Escherichia coli system. Recombinant of 66 kDa exhibited the highest catalytic activity at pH 9.0 and 55 °C. kcat/Km recombinant optimum condition reached 3.03 s−1 μM−1, which six times that commercial (0.5 μM−1). possessed a Km value 67.99 µM against dextran T70 substrate with 70 molecular weight. Thin-layer chromatography (TLC) analysis showed main hydrolysis end...

In 1994, the first DNAzyme named GR5 was reported, which specifically requires Pb2+ for its RNA cleavage activity. Three years later, 8-17 isolated. The and related 17E are also most active with , although other divalent metals can work as well. have same substrate sequence, their catalytic loops in enzyme strands a few similar conserved nucleotides. Considering these, we hypothesized that might be special form of GR5. To test this hypothesis, performed systematic rational evolution...

Both cations and anions in salt strongly affect the activity of a classic Pb²⁺ specific DNAzyme, which turn can sensitivity related biosensors.