The Cat Ba Biosphere Reserve is internationally renowned for its spectacular karst landscape. It covers a large area with hundreds of limestone islands and various ecosystems including caves, tropical forests, and mangroves. However, previous surveys were only conducted in terrestrial ecosystems on Cat Ba Island. Therefore, bats inhabiting mangroves and the remaining islands did not receive attention from scientists up to 2014. To initially fill in the gaps, we conducted ten bat surveys between 2015 and 2020 with an emphasis on mangroves and previously unsurveyed islands. Bats were captured using mist nets and harp traps. Twenty-three species belonging to 13 genera of six families were recorded during the surveys. Of these, four species (Macroglossus minimus, Myotis hasselti, Phoniscus jagorii, Tylonycteris fulvida) are new to the reserve. Remarkably, 15 species belonging to seven genera of five families were captured in mangrove, which is the highest species diversity for bats reported from any mangrove area in mainland Southeast Asia. Based on results from the surveys and literature review, we here provide the most updated bat diversity of the reserve with confirmed records of 32 bat species belonging to 16 genera of six families. Historical records of each species in the literature were reviewed. Two species, Scotophilus heathi and Scotophilus kuhlii, are unconfirmed because of unclear evidence in previous publications. Results of this study indicated that the mangrove ecosystem is important for bats but still poorly studied in Cat Ba Biosphere Reserve and Vietnam as a whole. In addition, morphological measurements, echolocation data, distributional records, and conservation status of each species are also given in this paper for potential research and conservation campaigns in the future.

Blumea lanceolaria (Roxb.) Druce, a flowering plant, is used for treating cancer and inflammatory diseases. In this study, we determined the chemical composition of the EOs extracted from the leaves (LBEO), stem (SBEO), and roots (RBEO) of B. lanceolaria and analyzed their anti-inflammation potential. Overall, 30 compounds representing 99.12%, 98.44%, and 96.89% of total EO constituents of the leaves, stem, and roots, respectively, were identified using GC-MS. ELISA, Western blotting, and qRT-PCR studies showed that LBEO, SBEO, and RBEO inhibited multiple steps in the inflammatory responses in the RAW 264.7 cell model, including NO production; TNF-α, IL-6, iNOS, and COX-2 transcription and translation; and phosphorylation of IκBα and p65 of the NF-κB pathway. In the carrageenan-induced paw edema model, all three EOs inhibited paw edema at both early and delayed phases. Molecular docking studies indicated that the main components of B. lanceolaria EOs (BEOs) targeted and inhibited major components of inflammation-related pathways, including the arachidonic acid metabolic pathway, NF-κB pathway, and MAPK pathway. We present the first study to characterize the chemical composition of BEOs and confirm their potent anti-inflammatory effects in in vitro, in vivo, and in silico analysis. These results can facilitate the development of effective anti-inflammatory drugs with limited side effects in the future.

Mangrove ecosystems play important ecological roles, including the mitigation of global climate change and biodiversity conservation. However, they have received little attention from scientists for the research and conservation of bats and general biodiversity. In Vietnam, bat species inhabiting mangroves have been relatively unstudied, while this ecosystem is located along the country’s coastal zones and has declined dramatically due to the development of agriculture, wind energy and other threats. To initially fill this gap, five bat surveys were conducted between September 2019 and November 2021 within Ha Long Bay and Ben Tre province, which contain representative mangrove areas of northern and southern regions of Vietnam, respectively. Bats were captured using mist nets, mobile nets and hand nets. Their echolocation calls were recorded and analyzed using the PCTape system and Selena software, respectively. Five species were captured and recorded: Cynopterus brachyotis, Macroglossus minimus, Myotis hasselti, Myotis pilosus and Taphozous melanopogon. They are all new to both Ha Long Bay and Ben Tre province. Four species (C. brachyotis, M. minimus, M. hasselti and M. pilosus) have been rarely documented from other ecosystems in Vietnam but have commonly been recorded and captured in mangrove areas. Of these species, M. pilosus is a globally “Vulnerable” species. While searching for prey, Myotis hasselti emitted high energy echolocation calls sweeping from about 96 to about 24 kHz with a signal duration of about 5 ms. This species sometimes uses social calls of a horseshoe-shaped structure, which last about 15 ms and are emitted about 26 ms in front of a search call. Results from our surveys indicated the importance and potential of mangroves for bat research and conservation.

Pwo DNA polymerase is an enzyme that is widely used in PCR due to its thermal stability and proofreading activity (3′-5′ exonuclease activity) with high accuracy. Optimizing the expression and purification of the protein is crucial to reducing the cost of production for this important enzyme. In this study, the higher expression level of the gene encoding Pwo DNA polymerase in bacteria strain E. coli BL21(DE3) was achieved by optimizing codon usage. The parameters of the gene encoding Pwo DNA polymerase obtained from the optimization: Number of Codons (ENc) = 28; Codon Adaptation Index (CAI) = 0.94; %GC = 48.4%. The codon-optimized gene was cloned into a pET-M expression vector and successfully expressed the Pwo DNA polymerase protein with a 6xHis-tag in E. coli BL21(DE3) cells. The recombinant protein was purified through a simple and rapid process involving two steps: cell lysis at high temperature combined with affinity chromatography using a Nickel column. The amount of Pwo DNA polymerase enzyme obtained from 1 liter of cell culture reached 32 mg. The protein yield in this study is higher than that of previous research while maintaining activity comparable to commercial enzymes. The activity of the Pwo DNA polymerase enzyme was tested at concentrations ranging from 60-150 µg/ml which showed to be equivalent or better than the commercially available Taq DNA polymerase from Promega. This result actively contributes to the production of the Pwo DNA polymerase enzyme and the study of its variants in the future.