Isolation and characterization of chlorpyrifos-degrading bacteria in tea-growing soils

The excess use of pesticides in the agricultural sector has caused environmental pollution and affected the complete ecosystem. Among the various commonly used pesticides, chlorpyrifos (CPF) is widely used against multiple agrarian pests due to its effectiveness and higher insecticidal activities. However, along with its beneficial usage, CPF has various residual effects on the environment, causing multiple negative impacts on aquatic organisms and human health. Consequently, methods for eliminating CPF in the background are essential. Among the currently available approaches to CPF remediation, biological methods using microorganisms are eco-friendly and cost-effective. Therefore, this study was conducted to isolate and characterize chlorpyrifos-degrading bacteria from the tea-growing soil of Vietnam. For this, soil samples were collected from the 20 tea-growing areas of Vietnam. From the collected samples, three bacterial strains viz., Methylobacterium populi CNN2, Ensifer adhaerens VNN3, and Acinetobacter pittii CNN4 have been isolated by using streak plate method and identified based on 16S rRNA gene analysis. The study results showed that under laboratory conditions, E. adhaerens VNN3 had the highest CPF degradation ability and was followed by the strain M. populi CNN2. In liquid medium, CPF concentration (100 mg/L) was reduced by 95.2% and 81.4% by E.adhaerens VNN3 and M. populi CNN2, respectively, after 72 h. Further, under in-vitro conditions, the concentration of CPF was reduced from 500 mg/kg to 112 ± 1.73 (77.6%) and 197 ± 2.08 mg/kg (60.6%) by E. adhaerens VNN3 and M. populi CNN2, respectively. Based on the obtained results, it can be concluded that E. adhaerens VNN3 and M. populi CNN2 can be used for CPF-contaminated agricultural soil remediation

Characterization of arsenic-resistant endophytic Priestia megaterium R2.5.2 isolated from ferns in an arsenic-contaminated multi-metal mine in Vietnam

Bioremediation is a biological process to remove or neutralize environmental pollutants. This study was carried out to investing at the efficacy of arsenic resistant endophytic bacteria isolated from Pteris vittata, Pityrogramma calomelanos, Blenchum orientale, and Nephrolepis exaltata, which grow in a highly arsenic (As) contamination mining site in Vietnam. Their segmented roots, stems, and leaves were homogenized separately and inoculated on LB agar plates containing 5mM As(III) and As(V). A total of 31 arsenic resistant endophytic strains were selected, in which strain R2.5.2 isolated from the root of P. calomelanos had the highest arsenic resistant capability. Strain R2.5.2 tolerated up to 320 mM and 160 mM of arsenate and arsenite, respectively. The strain developed well on a media of 0.1 5% NaCl, at 20-40ºC and pH 5 9, and actively utilized most of the sugar sources. It had a high IAA biosynthesis capacity with an average concentration of 19.14 mg/L, tolerated to 0.5-16 mM concentration of Ag+, Hg2+, Co2+, Ni2+, Cu2+, Cr4+, and reduced As(V). Based on 16s rDNA, R2.5.2 was identified as Priestia megaterium. The ars C gene coding for arsenate reductase catalyzing reduction of As(V) was successfully amplified in P. megaterium R2.5.2.  The selected strain may have potential use for bioremediation practice

The impacts of lead recycling activities to human health and environment in Dong Mai craft village, Hung Yen, Vietnam

Lead (Pb) recycling activities in Dong Mai village, Chi Dao commune, Van Lam district, Hung Yen province have been taking place for more than 30 years. The development of recycling activities contributed to the improvement of the local economics. However, along with economic development, Dong Mai craft village is facing to serious pollution. Soil, air and water polluted by lead (Pb) caused food containing Pb at higher levels than allowed limit from 20 to 40 times. The pollution had the bad effect on human health in this village. The investigation results showed that 100 % of employee who participated on melting lead and 63.5 % of local children were poisoned by Pb. Besides, the local people got diseases relating to skin, eyes, etc. This situation requires the provincial authorities to find immediate solutions to reduce the impacts of Pb recycling activities to environment and human.Hoạt động tái chế chì của thôn Đông Mai, xã Chỉ Đạo, huyện Văn Lâm, tỉnh Hưng Yên đã diễn ra hơn 30 năm nay. Sự phát triển của nghề tái chế đã làm góp phần cải thiện kinh tế của địa phương. Tuy nhiên, cùng với sự phát triển kinh tế, làng nghề Đông Mai đã và đang đối mặt với ô nhiễm môi trường nghiêm trọng. Môi trường đất, nước không khí bị ô nhiễm bởi chì (Pb) dẫn đến thực phẩm nhiễm chì ở hàm lượng cao hơn mức cho phép từ 20- 40 lần. Sự ô nhiễm gây ra những ảnh hưởng xấu tới sức khỏe của người dân làng nghề. Kết quả điều tra cho thấy 100% công nhân tham gia nấu chì và 63.5% trẻ em địa phương bị nhiễm độc chì. Bên cạnh đó, người dân địa phương còn bị mắc của các loại bệnh ngoài da, bệnh về mắt, …. Tình trạng này đòi hỏi chính quyền địa phương phải tìm ra giải pháp khẩn cấp để giảm thiểu tác động của những hoạt động tái chế chì tới môi trường và con người

Phosphorus treatment in wastewater by microorganisms isolated from cassava starch production waste

In waste water, phosphorous (P) can exist in inorganic or organic forms. Depending on the concentration, P can cause eutrophication and severe environmental pollution. Microorganisms have the ability to use and accumulate P, so microorganisms are studied to treat P in waste water in general and wastewater from cassava starch processing plants in particular. Research results show that in the 20 samples of waste water and sludge of the plant has selected three strains of bacteria that can accumulate P in the form of granules in the cell. Among them, SHV22 has the highest P accumulation capacity, reaching 3.05x10-11 mg/cell, P removal efficiency in wastewater from cassava starch processing factory is 82.1%. The strain was identified as Bacillus amyloliquefaciens.Trong nước thải P có thể tồn tại dưới dạng vô cơ hoặc hữu cơ. Tùy thuộc vào nồng độ, P có thể gây phú dưỡng và ô nhiễm môi trường nghiêm trọng. Vi sinh vật có khả năng sử dụng và tích lũy P, do đó vi sinh vật là đối tượng được nghiên cứu để xử lý P trong nước thải nói chung và nước thải của nhà máy chế biến tinh bột sắn nói riêng. Kết quả nghiên cứu cho thấy, trong 20 mẫu nước và bùn thải của nhà máy đã chọn lựa được 3 chủng vi khuẩn có khả năng tích lũy P dưới dạng hạt trong tế bào. Trong số đó, chủng SHV22 có khả năng tích lũy P cao nhất, đạt tới 3,05x10-11 mg/tế bào, hiệu quả loại bỏ P trong nước thải của nhà máy chế biến tinh bột sắn đạt 82,1%. Chủng đã được định danh là Bacillus amyloliquefaciens

Effects of some microelements on antifungal activity and biomass of the Actinomyces producing Validamycin-A

Validamycin A (Val-A) is an aminoglycoside's antibiotic with anti-fungal activity. Val-A synthesized by Streptomyces hygroscopicus strain depending on the growth and development of this actinomyces. In this study, the effects of Mn and Zn on the antifungal activity and biomass of the Streptomyces hygroscopicus were conducted. The results showed that micronutrients Mn, Zn had significant effects on biomass as well as antifungal activity of strain Streptomyces hygroscopicus- DA15. With the addition of Mn at a concentration of 1μg/l of the nutrient medium, biomass of Streptomyces hygroscopicus was 2.85±0.02g/ml, the anti-fungal Rhizoctoniasolani (R. solani) round diameter reached 3.5±0.2cm. With the addition of Zn=3μg/l of the nutrient medium, biomass of Streptomyces hygroscopicus DA15 was 4.5±0.02g/ml, the anti-fungal R. solani round diameter reached 3.4±0.2cm.Validamycin A (val-A) là một loại kháng sinh có khả năng kháng nấm, được tổng hợp bởi xạ khuẩn Streptomyces hygroscopicus và phụ thuộc vào quá trình sinh trưởng, phát triển của xạ khuẩn. Bài báo này đánh giá ảnh hưởng của nguyên tố vi lượng Mn, Zn đến hoạt tính kháng nấm Rhizoctonia solani (R. solani) và sinh khối của chủng Streptomyces hygroscopicus DA15. Khi bổ sung Mn vào môi trường nuôi cấy với nồng độ 1μg/l, sinh khối của Streptomyces hygroscopicus- DA15 đạt 2,85±0,02g/ml, đường kính vòng kháng nấm đạt 3,5±0,2cm. Bổ sung Zn vào môi trường nuôi cấy với hàm lượng Zn=3μg/l, sinh khối của Streptomyces hygroscopicus DA15 đạt 4,5±0,02g/ml và đường kính vòng kháng nấm đạt 3,4±0,2cm

Occurrence of antibiotic residues and antibiotic-resistant bacteria in effluents of pharmaceutical manufacturers and other sources around Hanoi, Vietnam

Pharmaceutical manufacturers in Vietnam are producing a wide variety of antibiotics for human and veterinary use. Consequently, the water discharged from those facilities can contain residues of antibiotics, which could have adverse impact on the environment. However, studies on the occurrence of antibiotics in the wastewater from pharmaceutical manufacturers in Vietnam are almost non-existent. In this study, water samples were collected at around the outlets of four pharmaceutical manufacturing plants as well as from a hospital and an aquaculture farm around Hanoi in 2016 and 2017. Fifteen antibiotics from four major classes (β-lactam, quinolones, macrolides, sulfonamides) were monitored, using a validated LC-MS/MS method, based on their number of registrations at the Ministry of Health. Ten antibiotics, ampicillin, cefuroxime, cefotaxime, clarithromycin, azithromycin, sulfamethoxazole, trimethoprim, ofloxacin, norfloxacin, and ciprofloxacin were detected in the samples at different concentrations. Notably, sulfonamides and quinolones were occasionally detected at very high concentration, such as sulfamethoxazole (252 μg/L), trimethoprim (107 μg/L), ofloxacin (85 μg/L), and ciprofloxacin (41 μg/L). In this study, concentrations of antibiotic residues in effluent of pharmaceutical plants were higher than those from other sources. The antibiotic-resistance tests indicated the widespread resistance to common antibiotics like quinolone and sulfonamides in the collected samples. This finding suggests that wastewater from pharmaceutical manufacturers could be an important source of antibiotics and antibiotic-resistant bacteria in the aquatic environment of Vietnam

Study on the possibility of using microorganisms as biological agents to control fungal pathogens Neoscytalidium dimidiatum causing disease of brown spots on the dragon fruit: Research article

Research and application of microbial control of brown spot disease on the dragon fruit caused by fungi Neoscytalidium dimetiatum have important implications towards the safe and sustainable dragon fruit production. In this article, the research team has identified two strains of microorganisms capable of inhibiting fungi Neoscytalidium dimitiatum denoted A3, B7. Classification results determined that A3 belongs to Actinomyces group 3 with similarities of 100% (1500/1500 bp) with 16S rDNA segment of Streptomyces fradiae; B7 with similarities of 100% (1414/1414 bp) with 16S rDNA segment of bacteria Bacillus polyfermenticus and ensure biosafety when released into the environment.Nghiên cứu ứng dụng vi sinh vật kiểm soát bệnh đốm nâu trên cây thanh long do nấm Neoscytalidium dimetiatum gây ra có ý nghĩa quan trọng hướng tới ngành sản xuất thanh long an toàn và bền vững. Trong bài viết này nhóm nghiên cứu đã xác định được hai chủng vi sinh vật có khả năng ức chế nấm Neoscytalidium dimitiatum cao kí hiệu là A3, B7. Kết quả phân loại xác định chủng A3 thuộc nhóm xạ khuẩn 3 tương đồng 100% (1500/1500 bp) với đoạn 16S rDNA của Streptomyces fradiae; chủng B7 tương đồng 100% (1414/1414 bp) với đoạn 16S của vi khuẩn Bacillus polyfermenticus và đảm bảo an toàn sinh học khi phóng thích ra môi trường

Status of heavy metal (Pb, Cd) pollution in agricultural soil in Dong Mai lead recycling craft village in Hung Yen, Vietnam

The newly planned lead recycling zone in Dong Mai village has been operating with primary treatment systems using lime to neutralize acid in wastewater is a good sign for the local environment, yet the real problem that needs further attention and proper solutions is the accumulation of heavy metals typically lead (Pb) and cadmium (Cd) in agricultural land near the old Pb recycling area. In this context, 27 soil samples were collected and analyzed by AAS method to assess the situation and the quality of the agricultural soil. The results showed that the levels of Cd in the soil were still in acceptable level according to National Regulation. However, the lead contents in all of the soil samples exceeded National Regulation. The level of Pb pollution in soil was inversely proportional to the distance with old lead melting zone. The lead content in the soil sample collected at the distance of 50 m radius to the old melting zone reached 7070 ppm, which was 100 times higher than the allowable value of National Regulation.Khu tái chế chì mới tại thôn Đông Mai đã được quy hoạch và đi vào hoạt động cùng hệ thống xử lý sơ bộ với vôi bột là một tín hiệu đáng mừng cho môi trường nơi đây, nhưng vấn đề cần quan tâm và giải quyết triệt để là sự tích lũy một lượng lớn kim loại nặng điển hình là chì (Pb) và cađimi (Cd) trong đất nông nghiệp gần những khu tái chế chì cũ. 27 mẫu đất đã được thu thập và phân tích bằng phương pháp AAS để đánh giá tình trạng, chất lượng đất nông nghiệp tại đây. Kết quả cho thấy hàm lượng Cd trong đất vẫn trong mức độ cho phép theo Quy chuẩn quốc gia. Tuy nhiên, 100% các mẫu đất đều có hàm lượng chì vượt quá mức cho phép theo Quy chuẩn quốc gia. Mức độ ô nhiễm Pb trong đất tỷ lệ nghịch với khoảng cách tới khu lò nấu chì cũ. Mẫu đất cách 50 m so với khu vực lò cũ có hàm lượng chì lên tới 7070 ppm, gấp hơn 100 lần so với Quy chuẩn quốc gia

Status of heavy metal (Pb, Cd) pollution in agricultural soil in Dong Mai lead recycling craft village in Hung Yen, Vietnam

The newly planned lead recycling zone in Dong Mai village has been operating with primary treatment systems using lime to neutralize acid in wastewater is a good sign for the local environment, yet the real problem that needs further attention and proper solutions is the accumulation of heavy metals typically lead (Pb) and cadmium (Cd) in agricultural land near the old Pb recycling area. In this context, 27 soil samples were collected and analyzed by AAS method to assess the situation and the quality of the agricultural soil. The results showed that the levels of Cd in the soil were still in acceptable level according to National Regulation. However, the lead contents in all of the soil samples exceeded National Regulation. The level of Pb pollution in soil was inversely proportional to the distance with old lead melting zone. The lead content in the soil sample collected at the distance of 50 m radius to the old melting zone reached 7070 ppm, which was 100 times higher than the allowable value of National Regulation.Khu tái chế chì mới tại thôn Đông Mai đã được quy hoạch và đi vào hoạt động cùng hệ thống xử lý sơ bộ với vôi bột là một tín hiệu đáng mừng cho môi trường nơi đây, nhưng vấn đề cần quan tâm và giải quyết triệt để là sự tích lũy một lượng lớn kim loại nặng điển hình là chì (Pb) và cađimi (Cd) trong đất nông nghiệp gần những khu tái chế chì cũ. 27 mẫu đất đã được thu thập và phân tích bằng phương pháp AAS để đánh giá tình trạng, chất lượng đất nông nghiệp tại đây. Kết quả cho thấy hàm lượng Cd trong đất vẫn trong mức độ cho phép theo Quy chuẩn quốc gia. Tuy nhiên, 100% các mẫu đất đều có hàm lượng chì vượt quá mức cho phép theo Quy chuẩn quốc gia. Mức độ ô nhiễm Pb trong đất tỷ lệ nghịch với khoảng cách tới khu lò nấu chì cũ. Mẫu đất cách 50 m so với khu vực lò cũ có hàm lượng chì lên tới 7070 ppm, gấp hơn 100 lần so với Quy chuẩn quốc gia

Ezetimibe added to statin therapy after acute coronary syndromes

BACKGROUND: Statin therapy reduces low-density lipoprotein (LDL) cholesterol levels and the risk of cardiovascular events, but whether the addition of ezetimibe, a nonstatin drug that reduces intestinal cholesterol absorption, can reduce the rate of cardiovascular events further is not known. METHODS: We conducted a double-blind, randomized trial involving 18,144 patients who had been hospitalized for an acute coronary syndrome within the preceding 10 days and had LDL cholesterol levels of 50 to 100 mg per deciliter (1.3 to 2.6 mmol per liter) if they were receiving lipid-lowering therapy or 50 to 125 mg per deciliter (1.3 to 3.2 mmol per liter) if they were not receiving lipid-lowering therapy. The combination of simvastatin (40 mg) and ezetimibe (10 mg) (simvastatin-ezetimibe) was compared with simvastatin (40 mg) and placebo (simvastatin monotherapy). The primary end point was a composite of cardiovascular death, nonfatal myocardial infarction, unstable angina requiring rehospitalization, coronary revascularization ( 6530 days after randomization), or nonfatal stroke. The median follow-up was 6 years. RESULTS: The median time-weighted average LDL cholesterol level during the study was 53.7 mg per deciliter (1.4 mmol per liter) in the simvastatin-ezetimibe group, as compared with 69.5 mg per deciliter (1.8 mmol per liter) in the simvastatin-monotherapy group (P<0.001). The Kaplan-Meier event rate for the primary end point at 7 years was 32.7% in the simvastatin-ezetimibe group, as compared with 34.7% in the simvastatin-monotherapy group (absolute risk difference, 2.0 percentage points; hazard ratio, 0.936; 95% confidence interval, 0.89 to 0.99; P = 0.016). Rates of pre-specified muscle, gallbladder, and hepatic adverse effects and cancer were similar in the two groups. CONCLUSIONS: When added to statin therapy, ezetimibe resulted in incremental lowering of LDL cholesterol levels and improved cardiovascular outcomes. Moreover, lowering LDL cholesterol to levels below previous targets provided additional benefit