scholarly journals Synergistic PAHs biodegradation by a mixed bacterial community: Based on a multisubstrate enrichment approach

2021 ◽  
Author(s):  
Kang Li ◽  
Yanzehua Liu ◽  
Yangda Li ◽  
Dan Li ◽  
Na Liu ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Aromatic Hydrocarbons ◽  
High Throughput Sequencing ◽  
Rrna Gene ◽  
Community Based ◽  
Ph Values ◽  
Intermediate Metabolites ◽  
Polycyclic Aromatic ◽  
Environmental Variations ◽  
Degradation Ability

Abstract Polycyclic aromatic hydrocarbons (PAHs) are highly hard-biodegradable compounds. Therefore, in this work, a multisubstrate enrichment approach was proposed to develop a bacterial community named MBF from activated sludge of coking wastewater plant capable of degrading mixed-PAHs consisting of phenanthrene and pyrene (50 mg/L of each) by 98.8% and 73.3% within 5 days, respectively. The bacterial community could maintain its degradation ability to mixed PAHs relatively under temperatures (20°C–35°C), pH values (5.0–9.0), and salinities (0–10 g/L NaCl). Additionally, the bacterial community MBF degraded 58.9%, 79.9%, and 80.7% of mixed PAHs in the presence of catechol, salicylic acid, and phthalic acid, respectively within 5 days. High-throughput sequencing of 16S rRNA gene amplicon analysis showed that the bacterial community MBF was dominated by Pseudomonas in most treatments, and Burkholderia was predominant under both acidic condition and high salt concentrations. Furthermore, the composition of microbial communities of the bacterial community was significantly different with/without addition of pathway intermediate metabolites after biodegradation of mixed PAHs, revealing the metabolic burden may be distributed between members of this bacterial community. Those results demonstrate that the biodegradation ability of MBF could be maintained with the bacterial community structure altering when facing environmental variations or changes in composition of target contaminants.

scholarly journals Correlation of Breed, Growth Performance, and Rumen Microbiota in Two Rustic Cattle Breeds Reared Under Different Conditions

2021 ◽  
Vol 12 ◽  
Author(s):  
Matteo Daghio ◽  
Francesca Ciucci ◽  
Arianna Buccioni ◽  
Alice Cappucci ◽  
Laura Casarosa ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Growth Performance ◽  
Community Composition ◽  
Lipid Composition ◽  
High Throughput Sequencing ◽  
Bacterial Community Composition ◽  
Daily Weight Gain ◽  
Rrna Gene ◽  
Rumen Microbiota ◽  
Cattle Breeds

The use of rustic cattle is desirable to face challenges brought on by climate change. Maremmana (MA) and Aubrac (AU) are rustic cattle breeds that can be successfully used for sustainable production. In this study, correlations between two rearing systems (feedlot and grazing) and the rumen microbiota, the lipid composition of rumen liquor (RL), and the growth performance of MA and AU steers were investigated. Bacterial community composition was characterized by high-throughput sequencing of 16S rRNA gene amplicons, and the RL lipid composition was determined by measuring fatty acid (FA) and the dimethyl acetal profiles. The main factor influencing bacterial community composition was the cattle breed. Some bacterial groups were positively correlated to average daily weight gain for the two breeds (i.e., Rikenellaceae RC9 gut group, Fibrobacter and Succiniclasticum in the rumen of MA steers, and Succinivibrionaceae UCG-002 in the rumen of AU steers); despite this, animal performance appeared to be influenced by short chain FAs production pathways and by the presence of H2 sinks that divert the H2 to processes alternative to the methanogenesis.

scholarly journals Effects of Salinity on the Biodegradation of Polycyclic Aromatic Hydrocarbons in Oilfield Soils Emphasizing Degradation Genes and Soil Enzymes

2022 ◽  
Vol 12 ◽  
Author(s):  
Yang Li ◽  
Wenjing Li ◽  
Lei Ji ◽  
Fanyong Song ◽  
Tianyuan Li ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Soil Salinity ◽  
Aromatic Hydrocarbons ◽  
Enzyme Activities ◽  
Soil Enzyme ◽  
Saline Soils ◽  
Soil Enzyme Activities ◽  
Pah Degradation ◽  
Pah Biodegradation ◽  
Polycyclic Aromatic

The biodegradation of organic pollutants is the main pathway for the natural dissipation and anthropogenic remediation of polycyclic aromatic hydrocarbons (PAHs) in the environment. However, in the saline soils, the PAH biodegradation could be influenced by soil salts through altering the structures of microbial communities and physiological metabolism of degradation bacteria. In the worldwide, soils from oilfields are commonly threated by both soil salinity and PAH contamination, while the influence mechanism of soil salinity on PAH biodegradation were still unclear, especially the shifts of degradation genes and soil enzyme activities. In order to explain the responses of soils and bacterial communities, analysis was conducted including soil properties, structures of bacterial community, PAH degradation genes and soil enzyme activities during a biodegradation process of PAHs in oilfield soils. The results showed that, though low soil salinity (1% NaCl, w/w) could slightly increase PAH degradation rate, the biodegradation in high salt condition (3% NaCl, w/w) were restrained significantly. The higher the soil salinity, the lower the bacterial community diversity, copy number of degradation gene and soil enzyme activity, which could be the reason for reductions of degradation rates in saline soils. Analysis of bacterial community structure showed that, the additions of NaCl increase the abundance of salt-tolerant and halophilic genera, especially in high salt treatments where the halophilic genera dominant, such as Acinetobacter and Halomonas. Picrust2 and redundancy analysis (RDA) both revealed suppression of PAH degradation genes by soil salts, which meant the decrease of degradation microbes and should be the primary cause of reduction of PAH removal. The soil enzyme activities could be indicators for microorganisms when they are facing adverse environmental conditions.

Molecular characterization and structure of intestinal micro flora for postmortem interval estimation in SD rats

2019 ◽  
Author(s):  
Huan Li ◽  
Lu Yuan ◽  
Ruina Liu ◽  
Siruo Zhang ◽  
E Yang ◽  
...  
Keyword(s):  
Bacterial Community ◽  
High Throughput Sequencing ◽  
Interval Estimation ◽  
Pcr Amplification ◽  
Postmortem Interval ◽  
The Body ◽  
Rrna Gene ◽  
Variable Regions ◽  
Time Points ◽  
Almost All

Abstract Background The human rectum flora consists of a huge variety of bacteria and the association between individuals and their rectum bacterial community begins presently after birth and continues the whole lifetime. Once the body dies, the inherent microbes begin to break down from the inside and play a key role thereafter. Results The aim of this study was to investigate the probable shift of the rectum flora at different time intervals up to 15 days after death and to characterize the contribution for of this shift to estimate the time of death. The rectum of rats was wiped with a sterile cotton swab and the samples were proceeded for DNA extraction, PCR amplification of the 16S rRNA gene with the V3+V4 variable regions, and high throughput sequencing carried out on IonS5TMXL platform. The results were analyzed for intra-group and inter-group diversity, similarity and difference at different time points. At phylum level, Proteobacteria and Firmicutes showed major shifts, checked at 11 different intervals and emerged in the most of postmortem intervals. At the genus level, Enterococcus appeared in all groups except alive samples, Lactobacillus and Proteus appeared in most time points, and the latter showed an increasing trend after 3 days postmortem samples. At the species level, Enterococcus_faecalis and Proteus_mirabilis existed in most postmortem intervals, and the former had a downward trend after day 5 postmortem, while the latter had an upward trend. Corynebacterium_amycolatum , Entero_isolate_group_2 , Bacteroides_uniformis , Enterococcus_faecalis , Streptococcus_gallolyticus_subsp_macedonics , Clostridium_sporogenes were more abundant in 0-hour, day 1, 3, 5, 7, 13 postmortem intervals, respectively, while Proteus_mirabilis and Vagococcus_lutrae were abundant in day 15 postmortem. In addition, functional capacity analysis of Membrane_Transport, Amino_Acid_Metabolism, Nucleotide_Metabolism and Energy_Metabolism showed significant differences between alive and almost all other time points after death ( P <0.05). Conclusions All in all, bacteria at different levels (phylum, genera, species) showed different characteristic during the process of decomposition and possessed entirely different relative abundance and the structure of bacterial community in each time point shifted obviously, which suggested that the specific bacteria might imply the specific postmortem interval during decomposition.

scholarly journals POTENSI TIGA ISOLAT BAKTERI INDIGEN DARI KABUPATEN SIAK PROVINSI RIAU DALAM MENDEGRADASI NAFTALENA

Jurnal Kimia ◽  
2020 ◽  
pp. 94
Author(s):  
R. Novianty ◽  
B. Antika ◽  
. Saryono ◽  
A. Awaluddin ◽  
N. W. Pratiwi
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Optical Density ◽  
Aromatic Hydrocarbons ◽  
Growth Response ◽  
Final Concentration ◽  
Pseudomonas Sp ◽  
Joint Operation ◽  
Polycyclic Aromatic ◽  
Degradation Ability

Naphthalene is a group of Polycyclic Aromatic Hydrocarbons (PAHs) which is carcinogenic when presents in the environment. The purpose of this study was to determine the growth response and test the effectiveness of three isolates of indigen bacteria from the Joint Operation Agency area of ??PT. Siak Bumi Pusako-Pertamina Hulu (BOB BSP-PHE) in degrading naphthalene. The three isolates were tested in a Minimum Media (MM) liquid containing naphthalene with a final concentration of 0.2 mM and was incubated for 7 days. Optical Density (OD) and the degradation ability were analyzed using a UV-Vis spectrophotometer. The results showed that Pseudomonas sp. LBKURCC149 was able to grow in media containing naphthalene. Naphthalene is used as the only source of carbon and is able to degrade naphthalene by 21.98%.   Keywords: biodegradation, indigenous, naphthalene, Pseudomonas sp.

scholarly journals Rice SST Variation Shapes the Rhizosphere Bacterial Community, Conferring Tolerance to Salt Stress through Regulating Soil Metabolites

mSystems ◽  
2020 ◽  
Vol 5 (6) ◽  
Author(s):  
Tengxiang Lian ◽  
Yingyong Huang ◽  
Xianan Xie ◽  
Xing Huo ◽  
Muhammad Qasim Shahid ◽  
...  
Keyword(s):  
Salt Stress ◽  
Bacterial Community ◽  
Management Practices ◽  
High Throughput Sequencing ◽  
Crop Productivity ◽  
Soil Salinization ◽  
Rrna Gene ◽  
Content Type ◽  
Rice Mutant ◽  
Rhizosphere Bacterial Community

ABSTRACT Some plant-specific resistance genes could affect rhizosphere microorganisms by regulating the release of root exudates. In a previous study, the SST (seedling salt tolerant) gene in rice (Oryza sativa) was identified, and loss of SST function resulted in better plant adaptation to salt stress. However, whether the rice SST variation could alleviate salt stress via regulating soil metabolites and microbiota in the rhizosphere is still unknown. Here, we used transgenic plants with SST edited in the Huanghuazhan (HHZ) and Zhonghua 11 (ZH11) cultivars by the CRISPR/Cas9 system and found that loss of SST function increased the accumulation of potassium and reduced the accumulation of sodium ions in rice plants. Using 16S rRNA gene amplicon high-throughput sequencing, we found that the mutant material shifted the rhizobacterial assembly under salt-free stress. Importantly, under salt stress, the sst, HHZcas, and ZH11cas plants significantly changed the assembly of the rhizobacteria. Furthermore, the rice SST gene also affected the soil metabolites, which were closely related to the dynamics of rhizosphere microbial communities, and we further determined the relationship between the rhizosphere microbiota and soil metabolites. Overall, our results show the effects of the rice SST gene on the response to salt stress associated with the soil microbiota and metabolites in the rhizosphere. This study reveals a helpful linkage among the rice SST gene, soil metabolites, and rhizobacterial community assembly and also provides a theoretical basis for improving crop adaptation through soil microbial management practices. IMPORTANCE Soil salinization is one of the major environmental stresses limiting crop productivity. Crops in agricultural ecosystems have developed various strategies to adapt to salt stress. We used rice mutant and CRISPR-edited lines to investigate the relationships among the Squamosa promoter Binding Protein box (SBP box) family gene (SST/OsSPL10), soil metabolites, and the rhizosphere bacterial community. We found that during salt stress, there are significant differences in the rhizosphere bacterial community and soil metabolites between the plants with the SST gene and those without it. Our findings provide a useful paradigm for revealing the roles of key genes of plants in shaping rhizosphere microbiomes and their relationships with soil metabolites and offer new insights into strategies to enhance rice tolerance to high salt levels from microbial and ecological perspectives.

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