Academia Journal of Biology

A discovery of the genus Philoplitis Nixon, 1965 (Hymenoptera: Braconidae: Microgastrinae) in Vietnam, with description of two new species

Dang Long Khuat — 2025-03-27

The small microgastrine genus Philoplitis Nixon, 1965 from Vietnam is newly recorded. As a result, two new species are described and fully illustrated, viz. Philoplitis ipunctatus Long, sp. nov. and Philoplitis cariniferus Long, sp. nov.. Additionally, the genus Philoplitis is recorded for the first time for Vietnam, and the comparative characters of Philoplitis species summarized in a table.

Phytochemical analysis, antioxidant, and antibacterial activities of crude and partially purified extracts of Portulaca oleracea leaves

EDWARD KEVIN BRAGAIS — 2025-03-27

The increasing antibiotic resistance among pathogens has driven the search for natural alternatives, particularly plant-based antimicrobials. This study investigates the antioxidant and antibacterial activities of Portulaca oleracea, a plant renowned for its polyphenolic constituents. The leaves were extracted using solvents of varying polarities to obtain different fractions for analysis. Qualitative phytochemical screening revealed a rich profile of polyphenolic compounds, including flavonoids, tannins, phenolic acids, and anthocyanins. The crude methanolic extract exhibited significant (p < 0.05) antioxidant activities against DPPH (50.08 ± 2.49%), superoxide (42.61 ± 0.56%), and hydroxyl (6.60 ± 0.94%). Furthermore, this extract demonstrated antibacterial efficacy, displaying zones of inhibition (ZOI) against Staphylococcus aureus (8.95 ± 0.19 mm) and Escherichia coli (7.18 ± 0.26 mm). Meanwhile, the polyphenol-rich aqueous fraction exhibited the highest antioxidant activities among the tested extracts (p < 0.05) with potent antibacterial activities against S. aureus (ZOI = 11.21 ± 0.11 mm) and E. coli (ZOI = 10.21 ± 0.18 mm). The bioactivities may be linked to polyphenolic compounds like quercetin, herbacetin, and rhamnetin, as identified by UPLC-MS. The high total phenolic content (181.58 ± 5.34 mg GAE/g) in the aqueous fraction aligns with its strong antioxidant and antibacterial effects (p < 0.05). These results suggest the potential of P. oleracea as a natural source of antibacterial agents and warrant further investigation into its mechanisms of action.

Expression of a drought-responsive helix-loop-helix transcription factor OsbHLH061 in rice (Oryza sativa ssp. japonica)

Thi Minh Thu Pham — 2025-03-27

Water scarcity poses a significant global challenge for agriculture, growing increasingly severe and widespread. Urgent measures are needed to develop crops that can withstand drought conditions. Recently, the method of transferring genes, particularly transcription factors, has emerged as a promising approach to enhance plant tolerance to stress. Genes are selected based on their differential expression patterns during stress, which can be identified through transcriptome analysis. In this research, the helix-loop-helix transcription factor OsbHLH061 was identified among up-regulated genes in microarray data derived from mRNA extracted from rice plants exposed to various abiotic stresses. The increased expression of OsbHLH061 under drought conditions was confirmed by quantitative real-time PCR (qRT-PCR). Its promoter analysis using the GUS reporter gene revealed spatial regulation of OsbHLH061 in germinating seeds, leaves, and root tips of young seedlings. Overexpression of OsbHLH061 was achieved by introducing the gene into rice plants under the control of the promoter of Rab21 in response to abscisic acid 21. However, transgenic plants did not exhibit any significant advantages in drought resistance compared to wild-type plants. These findings suggested the need for a different expression system. Moreover, the lack of significant changes in phenotype despite altering this transcription factor indicated a multi-locus nature of drought resistance associated with this gene.

Gut microbiota analysis of healthy and sacbrood virus-infected Apis mellifera reveals potential probiotic bacteria for honeybee health and disease resistance

Dong Van Quyen — 2025-03-27

This study aimed to determine the gut microbiota composition of adult Apis mellifera honeybees from bee farms in Bac Giang province, including both healthy colonies and those infected with Sacbrood virus (SBV). The gut microbiota of healthy and SBV-infected bees was assessed using next-generation sequencing (NGS) of the V3-V4 region in the 16S rRNA gene on the Illumina MiSeq system. As a result, NGS analysis identified 1,659 operational taxonomic units (OTUs) with a coverage of 99% and an average read length of 430 bp. The results revealed that SBV-infected bees harbored four microbial phyla: Proteobacteria (48.44%), Firmicutes (38.65%), Actinobacteria (1.57%), and Bacteria_uc (10.95%). In contrast, the healthy bee group consisted of three phyla: Proteobacteria (40.61%), Firmicutes (45.55%), and Bacteria_uc (13.37%). The species composition analysis showed that both healthy and SBV-infected bees shared common core bacterial species. However, Bifidobacterium_uc and Commensalibacter AY370188_s were more prevalent in SBV-infected bees and significantly reduced in healthy bees. Conversely, Fructobacillus fructosus and Lactobacillus kunkeei were found exclusively in healthy bees. These lactic acid bacteria (LAB) have been shown to inhibit the growth of pathogenic bacteria. Our findings provide a valuable scientific foundation for developing biological products to improve honeybee health and disease resistance.

Helminth parasites in wild rats from peninsular Malaysia oil palm plantation

Aidi Haidzil Johan — 2025-03-27

The presence of wild rats in oil palm plantations not only causes significant losses in crop production but also poses a potential threat to human health through the transmission of zoonotic diseases such as helminthiasis. This study determines the prevalence of helminths among the rat population in an oil palm plantation at Sungai Ara, Johor. By setting 100 metal live traps with baits, a total of 74 individual wild rats consisting of 6 species were successfully caught. Rats were euthanized and necropsied to examine internal organs for the presence of helminths. This study has revealed an overall infection rate of 91.9 %, (n = 68) and recorded several species from two groups of helminths: nematodes (Heterakis spumosa, Nippostrongylus brasiliensis, Syphacia muris, Hepatojarakus malayae, Angiostrongylus spp., Trichuris sp., and Capillaria hepatica) and cestodes (Cyst. Taenia taeniaeformis, Hymenolepis diminuta, and Hymenolepis nana). Among these helminths, several species have been identified as important zoonoses with the potential to infect humans such as taeniasis, hymenolepiasis and capillariasis.

Isolation and phylogenetic analysis of Staphylococcus aureus strains isolated from meat in traditional markets in Ha Noi

Dong Van Quyen — 2025-03-27

Staphylococcus aureus is a major cause of foodborne illness worldwide, causing diarrhea and vomiting. The rising number of S. aureus food poisoning cases in Vietnam underscores the urgent need for effective control strategies, particularly given the bacterium’s growing antibiotic resistance, complicating treatment options. This study investigates the public health risks posed by S. aureus in meat samples collected from traditional markets in Hanoi, Vietnam. A total of 30 bacterial isolates were obtained, of which six were identified as S. aureus using MALDI-TOF MS and confirmed through hemolysis testing and 16S rRNA sequencing. These isolates exhibited strong beta-hemolysis, indicating alpha-toxin production and their pathogenic potential. Notably, the antibiotic susceptibility test revealed that some isolated strains displayed varying levels of resistance to commonly used antibiotics, including aztreonam, streptomycin, amoxicillin, amikacin, and enrofloxacin. However, their uniform susceptibility to florfenicol, ceftiofur, doxycycline, and chloramphenicol suggests that these antibiotics remain effective for treating S. aureus infections in this region. Phylogenetic analysis revealed a high degree of genetic similarity between the isolated strains and globally distributed S. aureus strains associated with foodborne outbreaks in India, Korea, Japan, and Brazil, highlighting the potential for international transmission. These findings highlight the need for ongoing surveillance, improved food safety measures, and the development of updated antibiotic treatment protocols to manage the risks of S. aureus in the food supply.

Genetic variation of the D-loop region of the Kinh ethnic group from the northern, central, and southern Vietnam

Duy La — 2025-03-27

The displacement-loop (D-loop) region is the 1122 bp sequence of the mitochondrial DNA (mtDNA) that plays an important role in mtDNA replication and transcription. This region is also a hotspot for mutations, making it a good candidate for genetic diversity studies, especially when combined with other unique characteristics of the mitochondria. The Kinh, which accounts for approximately 90% of the Vietnamese population, has been extensively used as a representative of the Vietnamese population. In this study, we sampled and sequenced the mtDNA of 31 Kinh individuals from Central Vietnam and 33 Kinh individuals from Southern Vietnam. In combination with 50 Northern Kinh mtDNA sequences from a previous study, the present study analyzed the diversity of the Kinh across Vietnam through the D-loop region. After aligning to the reference mtDNA sequence RSRS (Reconstructed Sapiens Reference Sequence), 134 unique variants were found in the D-loop region, including 34 variants found in all three populations, 25 variants found in two populations, and 75 variants unique to one Kinh population. Haplogroup calling using Haplogrep3 identified 60 haplogroups, with 23 out of 60 being absent in the Northern Kinh population. Interestingly, despite the genetic diversity of the Kinh, four haplogroups were found in all three populations (F1a1a, F1a2, B5a, M7b1a1+(16192T)). The pairwise genetic distance analysis showed that the Northern Kinh is distinguishable from the Central Kinh while the other pairing experienced the opposite trend. By sampling the Kinh group in three different regions, our results provided the basis for further genetic diversity analysis of the Kinh across Vietnam.

Diversity and abundance of odonates (dragonflies and damselflies) and lepidopteran (butterflies) fauna of Kalyani Lake Park, Nadia district, West Bengal, India

Sayak Dolai — 2025-03-27

Butterflies, dragonflies and damselflies are indeed important for ecosystem productivity, playing roles in pollination and insect control, contributing to a balanced and thriving ecosystem. Their presence showcases the health and abundance of the ecosystem. Biodiversity protection and conservation are indeed essential aspects of both national and international agendas, as they contribute significantly to the sustainable development of regions and countries. Biodiversity ensures the health and stability of ecosystems, provides ecosystem services crucial for human survival and well-being, and supports various industries such as agriculture, fisheries, and tourism. Lepidoptera and Odonata assemblage along with Kalyani Lake Park of Nadia district in West Bengal has been investigated. The study on dragonflies, damselflies and butterfly species were conducted from August 2021 to September 2023. A modified “Pollard Walk” method was used to record species and abundance. In this survey, 25 species of dragonflies, 10 species of damselflies and 75 species of Butterflies were recorded. Among the odonate species, Libelluidae and Coenagrionidae were the dominant families with the maximum number of species being 23 and 08, respectively. In the case of butterflies, Nymphalidae was the dominant family with 27 species while others have fewer representatives. Relative abundance and diversity indices were calculated for all species groups. However, in the case of the urban forest area, the observed high anthropogenic disturbances create significant biotic pressure on the Kalyani Lake Park. Given the significance of understanding the insect diversity in this study area, a detailed list of recorded Odonata and Lepidoptera from the study would provide valuable insights into the specific species present, their distribution, and their potential interactions with the environment.

Role of yeast HAP4 gene in mitochondrial function, oxidative phosphorylation, and apoptosis in response to dna damage

Van Ngoc Bui — 2025-03-27

Apoptosis plays a crucial role in the normal development and differentiation of multicellular organisms and is essential for embryogenesis, metamorphosis, and elimination of unwanted cells. Like mammalian cells, yeast cells have evolved a number of cellular surveillance mechanisms including DNA damage checkpoint, stimulation of DNA repair, tolerance of DNA damage, and initiation of apoptosis. In Saccharomyces cerevisiae, the HAP4 gene encodes the Hap4 protein which is a subunit of the heme-activated, glucose-repressed Hap2p/3p/4p/5p complex. This complex plays a crucial role in controlling the TCA cycle, the mitochondrial electron transport chain, ATP production and mitochondria biogenesis. Thus, the purpose of this study is to investigate the role of the HAP4 gene by using the BY4742 (wild type) and specific knock-out yeast strains (∆hap4) to elucidate the role of this gene in mitochondrial function and respiration, ATP synthesis, and apoptosis in response to DNA damage triggered by methyl methanesulfonate (MMS) treatment. The findings suggested that the fully functional mitochondria enhanced oxygen consumption and mitochondrial activity, attenuated ROS accumulation, and enabled efficient electron transport and ATP synthesis. High mitochondrial activity is performed as a cellular protective mechanism against oxidative stress. In contrast, deletion of the HAP4 gene (∆hap4), the main regulatory gene for the expression of respiratory proteins, caused a block of the electron transport chain, persistent inhibition of mitochondrial activity, thereby leading to a reduction of oxygen consumption. Low mitochondrial activity resulted in the development of oxidative stress, enhancement of sensitivity to DNA damaging agents. High intracellular ROS levels in ∆hap4 cells posed a significant threat to mitochondrial DNA damage, impairment of mitochondrial respiration, inhibition of glycolytic enzymes (GAPDH, PYK), repression of ATP synthesis, and subsequent induction of cell death (apoptosis).

Genetic diversity of the tall-stilt mangrove (Rhizophora apiculata Blume) in Southern Central Coast of Vietnam using SSR markers

Nhung Hong Nguyen — 2025-03-27

Rhizophora apiculata is one of the important mangrove species for coastal communities and the global ecosystem. However, it has been threatening due to land clearing and over-exploitation, particularly in the Southern Central Coast of Vietnam. The SSR-PCR analysis indicated low levels of genetic diversity in R. apiculata populations distributed in the Southern Central regions of Vietnam. The observed number of alleles (N_A) was 1.933 indicating a low polymorphism for surveyed overall loci in tested populations. The observed heterozygosity (H_O) was also less than 0.5 indicating low heterozygosity at the species level. The interpopulation genetic diversity for each locus ranged from 0.000 to 0.188 demonstrating a moderate genetic differentiation among tested populations. Results of AMOVA analysis indicated that genetic variation almost occurred within the population (88%). Moreover, genetic distances of R. apiculata populations were low (drifted less than 0.05) indicating the gene pool exchange. At the overall population level, two different groups were observed and confirmed from UPGMA analysis and genetic distance matrix data. To gain a comprehensive understanding of the genetic diversity of R. apiculata in the Southern Central Coast of Vietnam, it would be necessary to utilize more molecular markers and investigate the matter further in other coastline regions. This would provide recommendations for mangrove tree breeding and restoring the mangrove forests in Vietnam as well as support for coping with the change of global climate.

Chemical constituents of essential oil of the endemic zingiber species (Zingiberaceae) in Vietnam, and its activity

Hanh Nguyen Phuong — 2025-03-27

vvv

In vitro Litsea cubeba (Lour.) Pers development under indole-3-butyric acid and 6-benzylaminopurine effect via stem node culture

Thi Le Tho Luong — 2025-03-27

Litsea cubeba (Lour.) Pers. is a vital medicinal plant in traditional medicine. Despite its high economic efficiency, L. cubeba is grown mainly based on experience; the area is fragmented and small, L. cubeba cultivation has relied on methods such as cuttings or grafting, with limited research on in vitro tissue culture propagation. This study aims to create a clean in vitro bud material source for micropropagation of L. cubeba by adding indole-3-butyric acid (IBA) and
6-benzylaminopurine (6-BA) to the cultured medium. Research results show that sterilising
L. cubeba stems with HgCl₂ is more effective than NaClO. After 4 weeks of culture, adding IBA 1.0 mg.L^-1 gave the best shoot development results. In MS medium supplemented with 6-BA
2.0 mg.L^-1 gave the best growth results. The bud formation rate reached 100%, the bud colour was green, the buds were fat, and the stem and internodes were divided. The research results serve as a basis for building a process for quickly multiplying the L. cubeba from stem sections and creating a source of disease-free seeds to supply to the people.