scholarly journals Characterization and molecular analysis of the viable but nonculturable state of a yeast Candida sp. strain LN1 induced by high phenol concentrations

2021 ◽  
Author(s):  
Mengqi Xie ◽  
Luning Xu ◽  
Rong Zhang ◽  
Yan Zhou ◽  
Yeyuan Xiao ◽  
...  
Keyword(s):  
Molecular Analysis ◽  
Yeast Strain ◽  
Environmental Remediation ◽  
Phenol Degradation ◽  
Surface Damage ◽  
Vbnc State ◽  
Molecular Changes ◽  
Survival Status ◽  
Candida Sp ◽  
Degrading Bacteria

Microbial degradation plays an important role in the environmental remediation. However, most microorganisms’ pollutant-degrading capability is weakened due to their entry into a viable but non-culturable (VBNC) state. Despite there is some evidence for the VBNC state of pollutant-degrading bacteria, limited studies have been conducted to investigate the VBNC state of pollutant degraders among fungi. In this work, the morphological, physiological and molecular changes of a phenol-degrading yeast strain LN1 exposed to high phenol concentrations were investigated. The results confirmed that Candida sp. strain LN1, which possessed highly efficient capability in degrading 1000 mg/L of phenol, as well as high potential for aromatic compounds degradation, entered into the VBNC state after 14 h of incubation at 6000 mg/L phenol. Resuscitation of VBNC cells can restore their phenol degradation performance. Compared to normal cells, significant dwarfing, surface damage and physiological changes of VBNC cells were observed. Molecular analysis indicated that the down-regulated genes were related to oxidative stress response, xenobiotics degradation, carbohydrate and energy metabolism, whereas the up-regulated genes were related to RNA polymerase, amino acid metabolism, DNA replication and repair. This report revealed that a pollutant-degrading yeast strain entered into the VBNC state under high concentrations of contaminants, providing new insights into its survival status and bioremediation potential under stress. Importance The viable but non-culturable (VBNC) state is known to affect the culturability and activity of microorganisms. However, limited studies have been conducted to investigate the VBNC state of other pollutant degraders such as fungi. In this study, the VBNC state of a phenol-degrading yeast strain was discovered. In addition, comprehensive analysis of the morphological, physiological and molecular changes of the VBNC cells were performed. This study provides new insight into the VBNC state of pollutant degraders, and how they restored the activities that was inhibited by stressful conditions. Enhanced bioremediation performance of indigenous microorganisms could be expected by preventing and controlling the formation of VBNC state.

scholarly journals Bioutilization of Chicken Feather Wastes by Newly Isolated Keratinolytic Bacteria Into Protein Hydrolysates With Improved Functionalities

2021 ◽  
Author(s):  
Saugat Prajapati ◽  
Sushil Koirala ◽  
Anil Kumar Anal
Keyword(s):  
Amino Acid ◽  
Soluble Protein ◽  
Environmental Remediation ◽  
Amino Acid Profile ◽  
Total Soluble Protein ◽  
Feather Degradation ◽  
Biochemical Tests ◽  
Box Behnken Design ◽  
Degrading Bacteria ◽  
Chicken Farm

Abstract In this study, a novel feather-degrading bacteria B. amyloliquefaciens KB1 was isolated from chicken farm bed (CFB), identified by morphological, physico-biochemical tests followed by 16s rDNA analysis. Among observed isolates, bacterial isolate (KB1) showed the highest degree of feather degradation (74.78 ± 2.94 %) and total soluble protein (205 ± 0.03 mg/ g). Using the same species of bacteria, the optimum fermentation condition was found at 40 oC, pH 9, and 1 % (w/v) feather concentration that produced 260 mg/ g of soluble protein and 86.16 % feather degradation using response surface methodology in a Box-Behnken design space. The obtained hydrolysates exhibited bioactive properties. The amino acid profile showed the increase in concentration of essential amino acid compared with feather meal broth. The selection of safe screening source of this new bacteria in CFB produced hydrolysates with enhanced bioactivity applicable for food, feed, and cosmetic applications along with environmental remediation.

scholarly journals Isolation and identification of a high-efficiency phenol-degrading bacteria and optimization of its degradation conditions

2021 ◽  
Vol 293 ◽  
pp. 01028
Author(s):  
Haili Sun ◽  
Tianpeng Gao ◽  
Guohua Chang ◽  
Xisheng Tai ◽  
Ruiqi Yang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Sodium Chloride ◽  
Low Temperature ◽  
High Efficiency ◽  
Phenol Degradation ◽  
Pcr Amplification ◽  
Toxic Substances ◽  
Isolation And Identification ◽  
Gram Staining ◽  
Degrading Bacteria

Phenol is widely used in China, it not only pollutes the environment, but also accumulates toxic substances in the human body through the food chain, further harming humans. In this experiment, a strain of high-efficiency low-temperature degradation phenol bacteria B5 was selected from the soil contaminated by organic matter of Lanzhou. Through research methods such as Gram staining observation, DNA extraction, PCR amplification, sequencing and comparison, it was found that this strain was Pantoea agglomerans. Through the subsequent optimization of degradation conditions, it was found that the B5 strain can degrade 500mg/L of phenol to 24.8mg/L in 36h. The ability to degrade phenol is stronger between pH5.5-pH6.0, and the ability to degrade phenol is higher in a medium containing 4-8g/L sodium chloride. This research can provide certain theoretical guidance for phenol degradation.

scholarly journals Isolation and Identification of Phenol-Degrading Bacteria from Oil-Contaminated Sites

2021 ◽  
Vol 38 (1) ◽  
pp. 160-165
Author(s):  
Z.M. Usman ◽  
M.A. Said ◽  
F.A. Shehu ◽  
K. Abdussalam ◽  
T.M. Abdulrazak ◽  
...  
Keyword(s):  
Proteus Mirabilis ◽  
System Analysis ◽  
Bacterial Species ◽  
Phenol Degradation ◽  
Contaminated Sites ◽  
Isolation And Identification ◽  
Selective Enrichment ◽  
Enrichment Technique ◽  
Degrading Bacteria ◽  
Cupriavidus Pauculus

This work is aimed at isolating and identifying phenol-degrading bacteria from oil-contaminated sites. Five soil samples from three auto-mechanic workshops within Katsina metropolis were collected. The samples were analyzed by selective enrichment technique, which resulted in the isolation of four bacterial species. The species were further subjected to the Vitek 2 compact microbiological system analysis. Cupriavidus pauculus, Pontoea spp, Proteus mirabilis 1 and Proteus mirabilis 2 were identified. Result from the present study showed that the bacteria could utilize phenol as their carbon source. Proteus mirabilis 1 and Proteus mirabilis 2 showed lower phenol degradation potential, under similar conditions. Cupriavidus pauculus and Pontoea sp. showed significant increases (p<0.05) in their optical densities. The optical density increment is strongly correlated with increase in colony forming units of the bacteria. This study further showed that the isolates could tolerate high phenol concentrations and may serve as strong putative isolates in bioremediation of phenol-contaminated sites.

scholarly journals Investigation of Two Evolutionarily Unrelated Halocarboxylic Acid Dehalogenase Gene Families

1999 ◽  
Vol 181 (8) ◽  
pp. 2535-2547 ◽  
Author(s):  
Katja E. Hill ◽  
Julian R. Marchesi ◽  
Andrew J. Weightman
Keyword(s):  
Amino Acid ◽  
Molecular Analysis ◽  
Phylogenetic Trees ◽  
Gene Families ◽  
Amino Acid Sequences ◽  
Group I ◽  
Silent Genes ◽  
Degrading Bacteria ◽  
Group Ii ◽  
Almost All

ABSTRACT Dehalogenases are key enzymes in the metabolism of halo-organic compounds. This paper describes a systematic approach to the isolation and molecular analysis of two families of bacterial α-halocarboxylic acid (αHA) dehalogenase genes, called group I and group II deh genes. The two families are evolutionarily unrelated and together represent almost all of the αHAdeh genes described to date. We report the design and evaluation of degenerate PCR primer pairs for the separate amplification and isolation of group I and II dehgenes. Amino acid sequences derived from 10 of 11 group Ideh partial gene products of new and previously reported bacterial isolates showed conservation of five residues previously identified as essential for activity. The exception, DehD from a Rhizobium sp., had only two of these five residues. Group II deh gene sequences were amplified from 54 newly isolated strains, and seven of these sequences were cloned and fully characterized. Group II dehalogenases were stereoselective, dechlorinating l- but not d-2-chloropropionic acid, and derived amino acid sequences for all of the genes exceptdehII°P11 showed conservation of previously identified essential residues. Molecular analysis of the twodeh families highlighted four subdivisions in each, which were supported by high bootstrap values in phylogenetic trees and by enzyme structure-function considerations. Group Ideh genes included two putative cryptic or silent genes, dehI°PP3 anddehI°17a, produced by different organisms. Group II deh genes included two cryptic genes and an active gene, dehII PP3, that can be switched off and on. All αHA-degrading bacteria so far described were Proteobacteria, a result that may be explained by limitations either in the host range fordeh genes or in isolation methods.

scholarly journals Assembly of CaIn2S4 on Defect-Rich BiOCl for Acceleration of Interfacial Charge Separation and Photocatalytic Phenol Degradation via S-Scheme Electron Transfer Mechanism

Catalysts ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1130
Author(s):  
Zhuangzhuang Zhang ◽  
Yuanyuan Zhang ◽  
Xuanxuan Han ◽  
Li Guo ◽  
Danjun Wang ◽  
...  
Keyword(s):  
Charge Separation ◽  
Environmental Remediation ◽  
Oxygen Vacancies ◽  
Phenol Degradation ◽  
Superior Performance ◽  
The Novel ◽  
Electron Transfer Mechanism ◽  
Synthetic Strategy ◽  
Interfacial Charge ◽  
High Temperature Calcination

The novel 2D/2D S-scheme heterostructure of BiOCl nanosheets coupled with CaIn2S4 nanosheets (CaIn2S4/BiOCl-SOVs), which contains surface oxygen vacancies (SOVs), has been successfully prepared by high-temperature calcination combined with a solvothermal synthetic strategy. Under visible-light irradiation, the apparent rate constant (Kapp/mim−1) for phenol degradation on the 1 wt% CaIn2S4/BiOCl-SOVs photocatalyst is about 32.8 times higher than that of pure BiOCl. The superior performance was attributed to the synergistic effect between the SOVs, CaIn2S4, and BiOCl, which can effectively narrow the bandgap and accelerate the interfacial charge separation of CaIn2S4/BiOCl-SOVs heterojunctions. Subsequently, it significantly promotes the generation of superoxide radicals (O2−), hydroxyl radicals, and h+, which participate in the photodegradation process of phenol. The catalyst still maintained a relatively high activity after repeated tests as a demonstration of its photostability. This work successfully proposed an efficient method to design a new 2D/2D S-scheme heterostructure with SOVs as possible photocatalysts in the field of environmental remediation.

Diversity of polyester-degrading bacteria in compost and molecular analysis of a thermoactive esterase from Thermobifida alba AHK119

2010 ◽  
Vol 87 (2) ◽  
pp. 771-779 ◽  
Author(s):  
Xiaoping Hu ◽  
Uschara Thumarat ◽  
Xian Zhang ◽  
Ming Tang ◽  
Fusako Kawai
Keyword(s):  
Molecular Analysis ◽  
Degrading Bacteria

scholarly journals Characterization of Phenol Degrading Bacteria from Buntal Lake of Central Kalimantan

2001 ◽  
Vol 3 (2) ◽  
pp. 24-31
Author(s):  
Nursaadah . ◽  
Dwi Andreas Santosa ◽  
Maggy T Suhartono
Keyword(s):  
Energy Source ◽  
Yeast Extract ◽  
Specific Activity ◽  
Phenol Degradation ◽  
Bacterial Isolates ◽  
Central Kalimantan ◽  
Degrading Bacteria ◽  
Optimum Ph ◽  
Degradation Ability

Three bacterial isolates (ICBB 1168, ICBB 1169, ICBB 1170), being capable to utilizing phenol as sole carbon and energy source, were isolated from Buntal Lake of Central Kalimantan. Growth of all isolates were optimum at 37OC. Optimum pH for growth and phenol degradation of ICBB 1168, lCBB 1169, and ICBB 1170 were 7-8, 6, and 6-7, respectively. Among the isolates, ICBB 1170 showed best phenol degrading activity. ICBB 1170 able to degrade 16 mM phenol to 0.71 mM in 4days. Phenol degradation ability of ICBB 1170 could be increased by adding 0.01-0.1% yeast extract. Addition of 0.05-0.1% glucose in medium inhibited phenol degradation by ICBB 1170. Cell-free extracts of ICBB 1170 had specific activity 2.92 Ulmg. Degradation of benzoate by ICBB 1170 wasstudied. However, the ability to degrade phenol were higher than that of benzoate.

Immobilization of halophilic yeast for effective removal of phenol in hypersaline conditions

2017 ◽  
Vol 77 (3) ◽  
pp. 706-713 ◽  
Author(s):  
Yu Jiang ◽  
Kai Yang ◽  
Tao Deng ◽  
Bin Ji ◽  
Yu Shang ◽  
...  
Keyword(s):  
Immobilized Cells ◽  
Phenol Degradation ◽  
Phenol Removal ◽  
Phenol Biodegradation ◽  
Nano Sio2 ◽  
Candida Sp ◽  
Halotolerant Yeast ◽  
Effective Removal ◽  
Degradation Rates ◽  
Effects Of Ph

Abstract A halotolerant yeast strain of Candida sp. was purified for phenol biodegradation and was immobilized in alginate and nano-SiO2. The concentration of nanoscale SiO2 was optimized and phenol degradation performance with different initial phenol concentrations was evaluated. Three common kinetic models were used to correlate the experimental data. The effects of pH and salinity on phenol biodegradation were also investigated. It was found that 1.0% (w/v) was the optimal nano-SiO2 concentration and the immobilized cells had a better phenol removal performance compared to free cells. More than 99% of 600 mg l−1 phenol was removed by the immobilized strains within 48 h. The immobilized cells also showed highest phenol degradation rates when pH and salinity were 6.5 and 0%, respectively. The high removal efficiency of phenol in reusability tests indicated the promising application of the immobilized Candida strain in phenol degradation under hypersaline conditions over a long period.

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