CSDL Bài trích Báo - Tạp chí
chủ đề: Biological science
1 Evaluation on the Zn2+ ion adsorption capacity in water of Spirulina platensis biomaterial / Hoang Thi Quynh, Duong Thi Thuy, Doan Thi Oanh, Nguyen Thi Nhu Huong, Le Phuong Thu, Nguyen Mai Lan, Bui Nguyen Minh Thu, Nguyen Duc Dien // Công nghệ sinh học - Vietnam Journal of Biotechnology .- 2022 .- Vol 20 .- P. 565-572 .- 363
In this study, the bioadsorption of Zn2+ ions in an assumed aqueous solution by the dry biomass of S. platensis TH was investigated. The Zn2+ ion adsorption of biomaterials was evaluated under different conditions, including pH, contact time, temperature, and adsorbent mass. The optimal Zn2+ ion removal efficiency reached 90.32 ± 0.29% at Zn2+ ion concentration of 100 mg/L, pH 5.0, a temperature of 26oC, and a dry biomass dose of 1.5 g/L for 90 min. Langmuir and Freundlich's isothermal models were used to describe the adsorption isotherm of Zn2+ ions on S. platensis TH. Equilibrium data fitted well with the Langmuir model as well as the Freundlich model, with a maximum adsorption capacity of 34.56 mg Zn2+/g S. platensis TH under the reaction conditions of 1.5 g/L biomass dosage, the contact time of 90 min, pH 5.0, at 26oC.
2 Effects of augmentation with Bacillus sp. DT1 on carbonfuran degradation and bacterial community in soil / Ha Danh Duc, Tran Dat Huy, Nguyen Thi Thanh, Ha Huynh Hong Vu, Nguyen Thanh Hung, Tran Ngoc Chau // Academia Journal of Biology .- 2022 .- Vol 44 - N2 .- P. 13-20 .- 570
Carbofuran is frequently applied to crop fields to combat insects globally causing serious environmental pollution. In this study, the enhanced degradation of carbofuran in soil by augmentation with Bacillus sp. DT1 was determined. The results showed that the augmentation with the bacterial strain increased the degradation by almost 30% compared to attenuation after 30 days at an initial concentration of 10 mg/kg dry soil. The half-life values of the insecticide were 41.6 and 17.9 days for attenuation and augmentation, respectively. Moreover, the augmentation with Bacillus sp. DT1 significantly increased sequence numbers of 16 S rRNA in soil compared to the initial stage. However, α-diversity indices, i.e., values of OTUs, ACE, Chao1 and Shannon showed no statistical differences in soil with and without the insecticide addition, with and without augmentation after 30 days. These results showed that carbofuran did not inhibit or stimulate the growth of soil bacteria at 10 mg/kg dry soil.
3 Trematode larval infections in snails collected from aquaculture ponds in Ha Noi and Yen Bai, Vietnam / Nguyen Manh Hung // Academia Journal of Biology .- 2022 .- Vol 44 - N2 .- P. 43-52 .- 570
The hot-spots of transmission of food-borne zoonotic trematodes in northern Vietnam have been known as the integrated fish-livestock (VAC- Garden, Fish pond, Poultry shed) ponds. A cross-sectional study was conducted in Ha Noi capital and Yen Bai province to investigate the trematode larval infections (cercariae) in freshwater snails in these areas. Snails were collected from 35 VAC ponds, including 25 grow-out and 10 nursery ponds. A total of 13,895 specimens of 12 snail species were examined for cercariae shedding. Six of 12 snail species including Melanoides tuberculata, Tarebia granifera, Radix auriculata, Gyraulus convexiusculus, Bithynia fuchsiana and Parafosarulus manchouricus, shed cercariae. Seven cercarial types were detected. The amount of snails and the prevalent infection in nursery ponds were 1.14 and 1.3 times higher than in grow-out ponds, respectively. Thus, VAC ponds in northern Vietnam are still the hot-spot for trematode larval infection.
4 N-alkanol stress-induced cell envelope injury of σE promoter in Escherichia coli / Huong Thi Bui // Academia Journal of Biology .- 2022 .- Vol 44 - N2 .- P. 91-104 .- 570
To characterize the cellular stress by n-alkanols with different alkyl chain lengths in Escherichia coli, we investigated how n-alkanols damage cell envelope permeability and whether they enhance the promoter activity of the envelope stress response regulator, σE, by using variants of green fluorescent protein (GFP). By using E. coli cells having GFPuv expressing and localizing in the cytoplasm, the inner membrane, and the periplasm, after exposure to n-alkanols, the fluorescent intensity of GFPuv released from cells was examined. Our data showed that at the similar levels of cell death of about 90–97%, ethanol, a short-chain alkanol, at a concentration of 20% damaged the outer membrane more greatly than the inner membrane, whereas a longer-chain alkanol of pentanol at a concentration of 1.125% damaged both of the outer and inner membranes. Then we investigated the envelope stress response to n-alkanols by σE factor by ratiometric analysis of rpoE promoter activity for the downstream GFPuv expression referenced to that of housekeeping sigma 70 (σ70 ) recognizing lacUV5 promoter for red fluorescent protein (RFP) expression. The results indicated that the relative activity of rpoE promoter by pentanol was much greater than that of ethanol. The degree of its sensitization by rpoE deficiency was much more remarkable for cells treated with pentanol than for those with ethanol. The results suggest that the response of the σE plays a significant role in the membrane integrity and survival of E. coli cells treated with n-alkanols depending on the alkyl chain length of the molecule.