scholarly journals Characterization of extracellular polymeric substances produced during nitrate removal by a thermophilic bacterium Chelatococcus daeguensis TAD1 in batch cultures

RSC Advances ◽  
2017 ◽  
Vol 7 (70) ◽  
pp. 44265-44271 ◽  
Author(s):  
Zhendong Wei ◽  
Shaobin Huang ◽  
Yongqing Zhang ◽  
Han Li ◽  
Shaofeng Zhou
Keyword(s):  
Removal Efficiency ◽  
Extracellular Polymeric Substances ◽  
Nitrate Removal ◽  
Thermophilic Bacterium ◽  
Aerobic Denitrification ◽  
Batch Cultures ◽  
Positive Correlation

Positive correlation was observed between EPS production and nitrate removal efficiency during aerobic denitrification byChelatococcus daeguensisTAD1.

scholarly journals Denitrification performance of Pseudomonas fluorescens Z03 immobilized by graphene oxide-modified polyvinyl-alcohol and sodium alginate gel beads at low temperature

2020 ◽  
Vol 7 (3) ◽  
pp. 191542 ◽  
Author(s):  
Meizhen Tang ◽  
Jie Jiang ◽  
Qilin Lv ◽  
Bin Yang ◽  
Mingna Zheng ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Low Temperature ◽  
Polyvinyl Alcohol ◽  
Pseudomonas Fluorescens ◽  
Sodium Alginate ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Extracellular Polymeric Substances ◽  
Aerobic Denitrification ◽  
Gel Beads

Improving the effect of microbial denitrification under low-temperature conditions has been a popular focus of research in recent years. In this study, graphene oxide (GO)-modified polyvinyl-alcohol (PVA) and sodium alginate (SA) (GO/PVA–SA) gel beads were used as a heterotrophic nitrification–aerobic denitrification (HN–AD) bacteria ( Pseudomonas fluorescens Z03) carrier to enhance nitrogen removal efficiency levels at low temperatures (6–8°C). The removal efficiency of N H 4     + -N and N O 3       − -N and the variations in concentrations of extracellular polymeric substances (EPS) under different GO doses (0.03–0.15 g l −1 ) were studied. The results indicated that the addition of GO can improve the efficiency of nitrogen removal, and the highest removal efficiency level and highest carbohydrate, protein, and total EPS content levels (50.28 mg, 132.78 mg and 183.06 mg (g GO/PVA–SA gel) −1 , respectively) were obtained with 0.15 g l −1 GO. The simplified Monod model accurately predicted the nitrogen removal efficiency level. These findings suggested that the application of GO serves as an effective means to enhance nitrogen removal by stimulating the activity of HN–AD bacteria.

Optimal operations for groundwater denitrification of drinking water using heterotrophic biological denitrification process

2006 ◽  
Vol 6 (2) ◽  
pp. 125-130
Author(s):  
C.-H. Hung ◽  
K.-H. Tsai ◽  
Y.-K. Su ◽  
C.-M. Liang ◽  
M.-H. Su ◽  
...  
Keyword(s):  
Drinking Water ◽  
Removal Efficiency ◽  
Nitrate Removal ◽  
Drinking Water Treatment ◽  
Nitrate Content ◽  
Source Water ◽  
Nitrogen Gas ◽  
Negative Effect ◽  
Denitrification Process ◽  
Heterotrophic Denitrification

Due to the extensive application of artificial nitrogen-based fertilizers on land, groundwater from the central part of Taiwan faces problems of increasing concentrations of nitrate, which were measured to be well above 30 mg/L all year round. For meeting the 10 mg/L nitrate standard, optimal operations for a heterotrophic denitrification pilot plant designed for drinking water treatment was investigated. Ethanol and phosphate were added for bacteria growing on anthracite to convert nitrate to nitrogen gas. Results showed that presence of high dissolved oxygen (around 4 mg/L) in the source water did not have a significantly negative effect on nitrogen removal. When operated under a C/N ratio of 1.88, which was recommended in the literature, nitrate removal efficiency was measured to be around 70%, sometimes up to 90%. However, the reactor often underwent severe clogging problems. When operated under C/N ratio of 1.0, denitrification efficiency decreased significantly to 30%. Finally, when operated under C/N ratio of 1.5, the nitrate content of the influent was almost completely reduced at the first one-third part of the bioreactor with an overall removal efficiency of 89–91%. Another advantage for operating with a C/N ratio of 1.5 is that only one-third of the biosolids was produced compared to a C/N value of 1.88.

Characterization of a Thermostable Xylanase from the Extremely Thermophilic Bacterium Thermotoga hypogea

2013 ◽  
Vol 2 (4) ◽  
pp. 325-333 ◽  
Author(s):  
Jasleen Dhanjoon ◽  
Xiangxian Ying ◽  
Fariha Salma ◽  
Kesen Ma
Keyword(s):  
Thermophilic Bacterium ◽  
Thermostable Xylanase

Characterization of a Thermostable Xylanase from the Extremely Thermophilic Bacterium Thermotoga hypogea

2013 ◽  
Vol 999 (999) ◽  
pp. 7-8
Author(s):  
Jasleen Dhanjoon ◽  
Xiangxian Ying ◽  
Fariha Salma ◽  
Kesen Ma
Keyword(s):  
Thermophilic Bacterium ◽  
Thermostable Xylanase

scholarly journals Biofilm Formation in Xanthomonas arboricola pv. pruni: Structure and Development

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 546
Author(s):  
Pilar Sabuquillo ◽  
Jaime Cubero
Keyword(s):  
Biofilm Formation ◽  
Extracellular Polymeric Substances ◽  
Environmental Changes ◽  
Nutrient Content ◽  
Infection Process ◽  
Bacterial Attachment ◽  
Key Factors ◽  
Cell Structures ◽  
Microscopy Techniques

Xanthomonasarboricola pv. pruni (Xap) causes bacterial spot of stone fruit and almond, an important plant disease with a high economic impact. Biofilm formation is one of the mechanisms that microbial communities use to adapt to environmental changes and to survive and colonize plants. Herein, biofilm formation by Xap was analyzed on abiotic and biotic surfaces using different microscopy techniques which allowed characterization of the different biofilm stages compared to the planktonic condition. All Xap strains assayed were able to form real biofilms creating organized structures comprised by viable cells. Xap in biofilms differentiated from free-living bacteria forming complex matrix-encased multicellular structures which become surrounded by a network of extracellular polymeric substances (EPS). Moreover, nutrient content of the environment and bacterial growth have been shown as key factors for biofilm formation and its development. Besides, this is the first work where different cell structures involved in bacterial attachment and aggregation have been identified during Xap biofilm progression. Our findings provide insights regarding different aspects of the biofilm formation of Xap which improve our understanding of the bacterial infection process occurred in Prunus spp and that may help in future disease control approaches.

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