scholarly journals Study on culture conditions of several strains of toluene-degrading bacteria isolated from common ornamental houseplants

2014 ◽  
Vol 6 (3) ◽  
pp. 201-207
Author(s):  
Due Thanh Phan ◽  
Thi Cuc Nguyen

This article studies the impact of some environmental conditions and the nutrition of culturing medium on the growth of bacteria and theirs capacity of toluene removal. The 5 bacterial strains isolated from leaf samples of three different common houseplants in Vietnam are Gram-negative, rod-shaped bacteria. The cells are single or arranged in chains. The cell size is relatively small and ranged from 0.7 to 2.5mm. These bacteria prefer the incubating temperature from 28°C to 32°C and a neutral pH 6.5 to 7.5. They are able to assimilate different nitrogen and carbon sources. In the liquid SH1 medium containing 200ppm toluene five selected strains have shown the ability to degrade toluene at a rate of 12.8 to 75.2% in comparison with the control at 30°C at a speed of 200rpm for over 120 hours. These 5 studied strains are potentially useful in bioremediation strategies to remove airborne toluene. 5 chủng vi khuẩn có khả năng phân giải toluene được phân lập từ lá một số cây cảnh phổ biến ở Việt Nam là vi khuẩn G (-), dạng trực khuẩn và kích thước tế bào từ 0,7 – 2,5m. Một số điều kiện môi trường nuôi cấy thích hợp cho 5 chủng vi khuẩn nghiên cứ gồm nhiệt độ 28°C-32°C, pH 6,5-7,5, có khả năng đồng hoá nhiều nguồn nitơ và ba nguồn carbon khác nhau. Trong điều kiện môi trường dịch SH1 chứa 200ppm toluene, 5 chủng vi khuẩn này cho thấy khả năng phân giải toluene từ 12,8 – 75,2%. Đây là các chủng vi khuẩn có tiềm năng ứng dụng để loại bỏ toluene từ không khí ô nhiễm.

2020 ◽  
Vol 3 (1) ◽  
pp. 520-529
Author(s):  
Pham Hong Hien ◽  
Tran Van Mau ◽  
Nguyen Thanh Huyen ◽  
Tran Thi Dao ◽  
Nguyen Van Giang ◽  
...  

In this study, with the aim of determining and assessing the influence of several culture conditions on the ligninolytic enzyme (LiP, MnP, and Lac) activity of bacteria, five lignin-degrading bacteria strains were isolated from two different soil samples and cultured on minimum salt medium agar containing alkaline lignin (MSML agar). Among the five isolated strains, DL1 and X3 expressed strong and stable ligninase enzyme activity at various temperature levels (30°C, 37°C, 50°C, and 60°C) and were selected for further study. Notably, at 60°C, the ligninase activity of both strains lasted until the seventh day before decreasing. The effects of the culture medium conditions, namely, carbohydrate sources, nitrogen sources, and pH, on the ligninolytic system illustrated that both X3 and DL1 were able to generate good enzymatic activity at a pH range of 3.0 to 7.0. These strains could use various sources of carbohydrates and nitrogen, derived from glucose, lactose, peptone, meat extract, and yeast extract. In addition, the analyses of biochemical characteristics revealed that X3 was capable of hydrolyzing starch and cellulose, while DL1 was not. Therefore, the results of this study suggested the potential of applying selected lignin-degrading bacterial strains on lignin treatments of agricultural wastes.


Author(s):  
Xuanjiang Yang ◽  
Panpan Guo ◽  
Miao Li ◽  
Hualong Li ◽  
Zelin Hu ◽  
...  

(1) Objective: The objective of this study was to screen amoxicillin (AMX)-degrading bacterial strains in pig manure and optimize the fermentation conditions for these strains to achieve high fermentation rate, which can provide an effective way for the practical application of bacterial strains as antibiotic-degrading bacterial in treating livestock waste for antibiotic residues. (2) Methods: Antibiotic susceptibility tests and high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) were employed to screen AMX-degrading bacterial strains in pig manure. The culture conditions were optimized for AMX-degrading bacterial strains using Plackeet–Burman design (PBD), the steepest ascent design, and the response surface methods, coupled with the Box–Behnken design (BBD). The effects of culture time, temperature, rotator (mixing) speed, inoculum level, and initial pH value on the growth of AMX-degrading strains were investigated. Experimental data obtained from BBD were utilized to generate a second-order polynomial regression model for evaluating the effects of the tested variables on the optical density at 600 nm (OD600) of culture solutions as the growth indicator for the screened AMX-degrading strains. (3) Results: The initial pH, culture time, and the inoculum level had significant effects on the OD600 value (growth) of the screened AMX-degrading strains. The initial pH value was found to be the most critical factor influencing the growth of bacteria. The optimized culture condition for the bacterial growth determined by the response surface methodology was: the initial pH of 6.9, culture time of 52 h, and inoculum level of 2%. The average OD value of 12 different fermentation conditions in the initial fermentation tests in this study was 1.72 and the optimization resulted in an OD value of 3.00. The verification experiment resulted in an OD value of 2.94, which confirmed the adequacy of the optimization model for the determining the optimal culture condition. (4) Conclusions: The growth of the screened strain of AMX-degrading bacteria could be optimized by changing the fermentation conditions. The optimization could be achieved by using the Box–Behnken response surface method and Plackett–Burman experimental design.


2021 ◽  
Vol 9 (11) ◽  
pp. 2285
Author(s):  
Rafaela Perdigão ◽  
C. Marisa R. Almeida ◽  
Catarina Magalhães ◽  
Sandra Ramos ◽  
Ana L. Carolas ◽  
...  

This work aimed to develop a bioremediation product of lyophilized native bacteria to respond to marine oil spills. Three oil-degrading bacterial strains (two strains of Rhodococcus erythropolis and one Pseudomonas sp.), isolated from the NW Portuguese coast, were selected for lyophilization after biomass growth optimization (tested with alternative carbon sources). Results indicated that the bacterial strains remained viable after the lyophilization process, without losing their biodegradation potential. The biomass/petroleum ratio was optimized, and the bioremediation efficiency of the lyophilized bacterial consortium was tested in microcosms with natural seawater and petroleum. An acceleration of the natural oil degradation process was observed, with an increased abundance of oil-degraders after 24 h, an emulsion of the oil/water layer after 7 days, and an increased removal of total petroleum hydrocarbons (47%) after 15 days. This study provides an insight into the formulation and optimization of lyophilized bacterial agents for application in autochthonous oil bioremediation.


2019 ◽  
pp. 441-449
Author(s):  
Merike Merimaa ◽  
Eeva Heinaru ◽  
Merit Lehiste ◽  
Signe Viggor ◽  
Ain Heinaru

Successful bioaugmentation requires that bacterial strains introduced into the polluted area must be able to adapt to new environmental conditions and retain high enough catabolic activity. The strains should degrade pollutant present at high concentrations, while having high affinity for the pollutants for their thorough degradation. The transfer of genetic information from introduced donor strain to indigenous bacterial population increases the biodegradation potential. As laboratory-selected strains can be poor survivors and lose catabolic activity in mixed microbial ecosystems, the indigenous biodegradative strains isolated from the river water continuously polluted with phenolic compounds of oil shale leachate may serve as inoculants for bioaugmentation. We have shown that the native phenol- and p-cresol-degrading community could be grouped according to the presence of catabolic genes involved in catabolism of aromatic compounds. The selected representative strains of different catabolic types of degradation of phenol and p-cresol were identified as Pseudomonas mendocina (strain PCl) and P. jluorescens (strains PC! 8, PC24). Catabolic potential of these strains was studied on the basis of phenol hydroxylase, p-cresol methylhydroxylase and catechol 2,3-dioxygenase genes. The occurrence and conjugation of plasmid DNA were revealed in these strains. The ability of the selected strains to degrade several phenolic compounds in natural phenolic wastewater in which the compounds were present in multicomponent mixtures, was investigated through laboratory microcosm studies, To elucidate the extent of interactions among the used bacterial strains single and mixed cultures were set up. The biodegradation activity of strains in microcosms was examined through viable counts, consumption of phenolic compounds and detecting the presence of catabolic genes by hybridization, During the experiments (30 days) the introduced bacteria remained viable even when the substrates were depleted. The mixture of strains was more effective in the decomposition of phenolic compounds from the natural wastewater as compared with the single culture conditions and the metabolic activity and cell density of each strain were co-ordinated within a specific time scale. The behaviour of strains in the phenolic leachate depended on the growth kinetics of the strains (K,,µ).


Biomolecules ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1057
Author(s):  
Stefan Freischem ◽  
Immanuel Grimm ◽  
Arancha López-Pérez ◽  
Dieter Willbold ◽  
Burkhard Klenke ◽  
...  

Novel antimicrobial strategies are urgently required because of the rising threat of multi drug resistant bacterial strains and the infections caused by them. Among the available target structures, the so-called penicillin binding proteins are of particular interest, owing to their good accessibility in the periplasmic space, and the lack of homologous proteins in humans, reducing the risk of side effects of potential drugs. In this report, we focus on the interaction of the innovative β-lactam antibiotic AIC499 with penicillin binding protein 3 (PBP3) from Escherichia coli and Pseudomonas aeruginosa. This recently developed monobactam displays broad antimicrobial activity, against Gram-negative strains, and improved resistance to most classes of β-lactamases. By analyzing crystal structures of the respective complexes, we were able to explore the binding mode of AIC499 to its target proteins. In addition, the apo structures determined for PBP3, from P. aeruginosa and the catalytic transpeptidase domain of the E. coli orthologue, provide new insights into the dynamics of these proteins and the impact of drug binding.


Author(s):  
Singh Gurvinder ◽  
Singh Prabhsimran ◽  
Dhawan R. K.

In order to develop new antimicrobial agents, a series of 3-formyl indole based Schiff bases were synthesized by reacting 3-formyl indole(indole-3-carboxaldehyde) with substituted aniline taking ethanol as solvent. The reaction was carried in the presence of small amount of p-toluene sulphonic acid as catalyst.All the synthesized compounds were characterized by IR, 1H-NMR spectral analysis. All the synthesized compounds were evaluated for antimicrobial activity against two gram positive bacterial strains (B. subtilisand S. aureus) and two gram negative bacterial strains (P. aeruginosaand E. coli) and one fungal strain (C. albicans). All the synthesized compounds were found to have moderate to good antimicrobial activity. The  standard drug amoxicillin, fluconazole were used for antimicrobial activity. Among the synthesized compounds, the maximum antimicrobial activity was shown by compounds GS04, GS07, GS08 and GS10.


Author(s):  
V.V. Zinchenko ◽  
◽  
E.S Fedorenko ◽  
A.V Gorovtsov ◽  
T.M Minkina ◽  
...  

As a result of the model experiment, an increase in the enzymatic activity of meadow chernozem of the impact zone of Ataman Lake with the introduction of a strains mixture of metal-resistant microorganisms into the soil was established. The experiment has shown that the application of bacterial strains increases the dehydrogenase activity of contaminated soil by 51.8% compared to the variant without remediation


2020 ◽  
Author(s):  
Nusrat Abedin ◽  
Abdullah Hamed A Alshehri ◽  
Ali M A Almughrbi ◽  
Olivia Moore ◽  
Sheikh Alyza ◽  
...  

Antimicrobial resistance (AMR) has become one of the more serious threats to the global health. The emergence of bacteria resistant to antimicrobial substances decreases the potencies of current antibiotics. Consequently, there is an urgent and growing need for the developing of new classes of antibiotics. Three prepared novel iron complexes have a broad-spectrum antimicrobial activity with minimum bactericidal concentration (MBC) values ranging from 3.5 to 10 mM and 3.5 to 40 mM against Gram-positive and Gram-negative bacteria with antimicrobial resistance phenotype, respectively. Time-kill studies and quantification of the extracellular DNA confirmed the bacteriolytic mode of action of the iron-halide compounds. Additionally, the novel complexes showed significant antibiofilm activity against the tested pathogenic bacterial strains at concentrations lower than the MBC. The cytotoxic effect of the complexes on different mammalian cell lines show sub-cytotoxic values at concentrations lower than the minimum bactericidal concentrations.


2020 ◽  
Vol 36 (4) ◽  
pp. 126-135
Author(s):  
T.V. Shushkova ◽  
D.O. Epiktetov ◽  
S.V. Tarlachkov ◽  
I.T. Ermakova ◽  
A.A. Leontievskii

The degradation of persistent organophosphorus pollutants have been studied in 6 soil bacterial isolates and in 3 bacterial strains adapted for utilization of glyphosate herbicide (GP) under laboratory conditions. Significant differences in the uptake of organophosphonates were found in taxonomically close strains possessing similar enzymatic pathways of catabolism of these compounds, which indicates the existence of unknown mechanisms of activity regulation of these enzymes. The effect of adaptation for GP utilization as a sole phosphorus source on assimilation rates of several other phosphonates was observed in studied bacteria. The newly found efficient stains provided up to 56% of GP decomposition after application to the soil in the laboratory. The unresolved problems of microbial GP metabolism and the trends for further research on the creation of reliable biologicals capable of decomposing organophosphonates in the environment are discussed. organophosphonates, glyphosate, biodegradation, bioremediation, C-P lyase, phosphonatase, degrading bacteria Investigation of phosphonatase and genome sequencing were supported by Russian Science Foundation Grant no. 18-074-00021.


2020 ◽  
Vol 36 (2) ◽  
pp. 86-98
Author(s):  
A.A. Sergeeva ◽  
G.V. Ovechkina ◽  
A.Yu. Maksimov

Bacterial strains capable of degradation of 0.8-15.8 g/1 pyridine hydrochloride have been isolated from activated sludge of municipal biological treatment plants in Perm (BOS) and local treatment facilities of the LUKOIL-Permnefteorgsintez enterprise (PNOS). The strains were identified as Achromobacter pulmonis and Burkholderia dolosa. The optimal pyridine concentration for the growth of the isolated strains was 4.0 g/1. The pyridine degradation during the A. pulmonis PNOS and B. dolosa BOS cultivation on a medium with ammonium chloride and glucose and without additional nitrogen or carbon sources was studied. It was shown that the strains are able to accumulate biomass in a medium with pyridine as the sole carbon and nitrogen source; the addition of glucose to the medium (1 g/L) accelerated the pyridine degradation by A. pulmonis PNOS, but inhibited the process carried out by B. dolosa BOS. B. dolosa BOS and A. pulmonis PNOS biofilms efficiently utilized pyridine during growth on basalt and carbon fibers; the highest rate of pyridine utilization (1.8 g /(L day)) was observed in A. pulmonis PNOS biofilms on basalt fibers. pyridine, biodegradation, activated sludge, biofilms, Achromobacter pulmonis, Burkholderia dolosa The authors grateful to Dr. I.I. Tchaikovsky, Head of the Laboratory of Geology of Mineral Deposits of the Mining Institute, a branch of the Perm Federal Research Center, for help with electron microscopy of the samples. This work was carried out as part of a state assignment on the topic « Study of the Functional and Species Diversity of Microorganisms Useful for Ecocenoses and Human Practical Activity», registration number R&D AAAA-A19-119112290008-4.


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