1.Change of bacterial community structure during cellulose degradation by the microbial consortium.
Shiqi AI ; Yiquan ZHAO ; Zhiyuan SUN ; Yamei GAO ; Lei YAN ; Hongzhi TANG ; Weidong WANG
Chinese Journal of Biotechnology 2018;34(11):1794-1808
In order to clarify dynamic change of microbial community composition and to identify key functional bacteria in the cellulose degradation consortium, we studied several aspects of the biodegradation of filter papers and rice straws by the microbial consortium, the change of substrate degradation, microbial biomass and pH of fermentation broth. We extracted total DNA of the microbial consortium in different degradation stages for high-throughput sequencing of amplicons of bacterial 16 S rRNA genes. Based on the decomposition characteristics test, we defined the 12th, 72nd and 168th hours after inoculation as the initial stage, peak stage and end stage of degradation, respectively. The microbial consortium was mainly composed of 1 phylum, 2 classes, 2 orders, 7 families and 11 genera. With cellulose degradation, bacteria in the consortium showed different growth trends. The relative abundance of Brevibacillus and Caloramator decreased gradually. The relative abundance of Clostridium, Bacillus, Geobacillus and Cohnella increased gradually. The relative abundance of Ureibacillus, Tissierella, Epulopiscium was the highest in peak stage. The relative abundance of Paenibacillus and Ruminococcus did not change obviously in each stage. Above-mentioned 11 main genera all belonged to Firmicutes, which are thermophilic, broad pH adaptable and cellulose or hemicellulose degradable. During cellulose degradation by the microbial consortium, aerobic bacteria were dominant functional bacteria in the initial stage. However, the relative abundance of anaerobic bacteria increased gradually in middle and end stage, and replaced aerobic bacteria to become main bacteria to degrade cellulose.
Bacteria
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classification
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metabolism
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Biodegradation, Environmental
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Cellulose
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metabolism
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DNA, Bacterial
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genetics
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Microbial Consortia
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RNA, Ribosomal, 16S
;
genetics
2.Screening, domestication and identification of intestinal uric acid degrading bacteria in low uric acid population.
Tingting TIAN ; Wujin CHEN ; Meiting LIANG ; MAYINA KAHAER ; Rui LI ; Yuping SUN
Journal of Biomedical Engineering 2022;39(4):792-797
As the largest ecosystem of human body, intestinal microorganisms participate in the synthesis and metabolism of uric acid. Developing and utilizing intestinal bacteria to degrade uric acid might provide new ideas for the treatment of hyperuricemia. The fecal samples of people with low uric acid were inoculated into uric acid selective medium with the concentration of 1.5 mmol/L for preliminary screening, and the initially screened strains that may have degradation ability were domesticated by concentration gradient method, and the strains with high uric acid degradation rate were identified by 16S rRNA sequencing method. A strain of high-efficiency uric acid degrading bacteria was screened and domesticated from the feces of people with low uric acid. The degradation rate of uric acid could reach 50.2%. It was identified as Escherichia coli. The isolation and domestication of high efficient uric acid degrading strains can not only provide scientific basis for the study of the mechanism of intestinal microbial degradation of uric acid, but also reserve biological strains for the treatment of hyperuricemia and gout in the future.
Bacteria/metabolism*
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Domestication
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Ecosystem
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Escherichia coli/genetics*
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Humans
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Hyperuricemia
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RNA, Ribosomal, 16S/metabolism*
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Uric Acid/metabolism*
3.Structure and function of a novel thermostable pullulanase.
Jie ZHEN ; Zheng HU ; Shufang LI ; Jianyong XU ; Hui SONG
Chinese Journal of Biotechnology 2014;30(1):119-128
Research on novel pullulanase has major significance on the domestic industrialization of pullulanase and the breakdown of foreign monopoly. A thermophilic bacteria LM 18-11 producing thermostable pullulanase was isolated from Lunma hot springs of Yunnan province. It was identified as Anoxybacillus sp. by 16S rDNA phylogenetic analysis. Full-length pullulanase gene was cloned from Anoxybacillus sp. LM18-11. The optimum temperature of the pullulanase was between 55 and 60 degrees C with a half-life as long as 48 h at 60 degrees C; and its optimum pH was between 5.6 and 6.4. V(max) and K(m) of the pullulanase was measured as 750 U/mg and 1.47 mg/mL, which is the highest specific activity reported so far. The pullulanase crystals structure showed a typical alpha-amylase family structure. The N-terminal has a special substrate binding domain. Activity and substrate binding were decreased when the domain was deleted, the V(max) and K(m) were 324 U/mg and 1.95 mg/mL, respectively. The pullulanase was highly heterologous expressed in Bacillus subtilis by P43 promoter. The extracellular enzyme activity was 42 U/mL, which increased more than 40 times compared to the initial strain. This pullulanase has good application prospects.
Anoxybacillus
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classification
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enzymology
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China
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Glycoside Hydrolases
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metabolism
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Hydrogen-Ion Concentration
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Phylogeny
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RNA, Ribosomal, 16S
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genetics
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Temperature
4.Screening and identification of a polyurethane-degrading bacterium G-11 and its plastic degradation characteristics.
Zhitong JIANG ; Xue CHEN ; Jinhui LEI ; Huizhen XUE ; Bo ZHANG ; Xiaofan XU ; Huijing GENG ; Zhoukun LI ; Xin YAN ; Weiliang DONG ; Hui CAO ; Zhongli CUI
Chinese Journal of Biotechnology 2023;39(5):1963-1975
Polyurethane (PUR) plastics is widely used because of its unique physical and chemical properties. However, unreasonable disposal of the vast amount of used PUR plastics has caused serious environmental pollution. The efficient degradation and utilization of used PUR plastics by means of microorganisms has become one of the current research hotspots, and efficient PUR degrading microbes are the key to the biological treatment of PUR plastics. In this study, an Impranil DLN-degrading bacteria G-11 was isolated from used PUR plastic samples collected from landfill, and its PUR-degrading characteristics were studied. Strain G-11 was identified as Amycolatopsis sp. through 16S rRNA gene sequence alignment. PUR degradation experiment showed that the weight loss rate of the commercial PUR plastics upon treatment of strain G-11 was 4.67%. Scanning electron microscope (SEM) showed that the surface structure of G-11-treated PUR plastics was destroyed with an eroded morphology. Contact angle and thermogravimetry analysis (TGA) showed that the hydrophilicity of PUR plastics increased along with decreased thermal stability upon treatment by strain G-11, which were consistent with the weight loss and morphological observation. These results indicated that strain G-11 isolated from landfill has potential application in biodegradation of waste PUR plastics.
Plastics/metabolism*
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Polyurethanes/chemistry*
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RNA, Ribosomal, 16S
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Bacteria/genetics*
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Biodegradation, Environmental
5.Bioremediation of Hexavalent Chromium Pollution by Sporosarcina saromensis M52 Isolated from Offshore Sediments in Xiamen, China.
Ran ZHAO ; Bi WANG ; Qing Tao CAI ; Xiao Xia LI ; Min LIU ; Dong HU ; Dong Bei GUO ; Juan WANG ; Chun FAN ;
Biomedical and Environmental Sciences 2016;29(2):127-136
OBJECTIVECr(VI) removal from industrial effluents and sediments has attracted the attention of environmental researchers. In the present study, we aimed to isolate bacteria for Cr(VI) bioremediation from sediment samples and to optimize parameters of biodegradation.
METHODSStrains with the ability to tolerate Cr(VI) were obtained by serial dilution and spread plate methods and characterized by morphology, 16S rDNA identification, and phylogenetic analysis. Cr(VI) was determined using the 1,5-diphenylcarbazide method, and the optimum pH and temperature for degradation were studied using a multiple-factor mixed experimental design. Statistical analysis methods were used to analyze the results.
RESULTSFifty-five strains were obtained, and one strain (Sporosarcina saromensis M52; patent application number: 201410819443.3) having the ability to tolerate 500 mg Cr(VI)/L was selected to optimize the degradation conditions. M52 was found be able to efficiently remove 50-200 mg Cr(VI)/L in 24 h, achieving the highest removal efficiency at pH 7.0-8.5 and 35 °C. Moreover, M52 could completely degrade 100 mg Cr(VI)/L at pH 8.0 and 35 °C in 24 h. The mechanism involved in the reduction of Cr(VI) was considered to be bioreduction rather than absorption.
CONCLUSIONThe strong degradation ability of S. saromensis M52 and its advantageous functional characteristics support the potential use of this organism for bioremediation of heavy metal pollution.
Biodegradation, Environmental ; China ; Chromium ; metabolism ; Geologic Sediments ; microbiology ; RNA, Ribosomal, 16S ; genetics ; Sporosarcina ; genetics ; isolation & purification ; metabolism
6.Sequence analysis of 16S rDNA and pmoCAB gene cluster of trichloroethylene-degrading methanotroph.
Yunru ZHANG ; Huaqing CHEN ; Yanhui GAO ; Zhilin XING ; Tiantao ZHAO
Chinese Journal of Biotechnology 2014;30(12):1912-1923
Methanotrophs could degrade methane and various chlorinated hydrocarbons. The analysis on methane monooxygenase gene cluster sequence would help to understand its catalytic mechanism and enhance the application in pollutants biodegradation. The methanotrophs was enriched and isolated with methane as the sole carbon source in the nitrate mineral salt medium. Then, five chlorinated hydrocarbons were selected as cometabolic substrates to study the biodegradation. The phylogenetic tree of 16S rDNA using MEGE5.05 software was constructed to identify the methanotroph strain. The pmoCAB gene cluster encoding particulate methane monooxygenase (pMMO) was amplified by semi-nested PCR in segments. ExPASy was performed to analyze theoretical molecular weight of the three pMMO subunits. As a result, a strain of methanotroph was isolated. The phylogenetic analysis indicated that the strain belongs to a species of Methylocystis, and it was named as Methylocystis sp. JTC3. The degradation rate of trichloroethylene (TCE) reached 93.79% when its initial concentration was 15.64 μmol/L after 5 days. We obtained the pmoCAB gene cluster of 3 227 bp including pmoC gene of 771 bp, pmoA gene of 759 bp, pmoB gene of 1 260 bp and two noncoding sequences in the middle by semi-nested PCR, T-A cloning and sequencing. The theoretical molecular weight of their corresponding gamma, beta and alpha subunit were 29.1 kDa, 28.6 kDa and 45.6 kDa respectively analyzed using ExPASy tool. The pmoCAB gene cluster of JTC3 was highly identical with that of Methylocystis sp. strain M analyzed by Blast, and pmoA sequences is more conservative than pmoC and pmoB. Finally, Methylocystis sp. JTC3 could degrade TCE efficiently. And the detailed analysis of pmoCAB from Methylocystis sp. JTC3 laid a solid foundation to further study its active sites features and its selectivity to chlorinated hydrocarbon.
Methylocystaceae
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classification
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metabolism
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Multigene Family
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Oxygenases
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genetics
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Phylogeny
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Polymerase Chain Reaction
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RNA, Ribosomal, 16S
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genetics
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Sequence Analysis, DNA
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Trichloroethylene
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metabolism
7.Isolation and characterization of a new heterotrophic nitrifying Bacillus sp. strain.
Yan LIN ; Hai-Nan KONG ; Yi-Liang HE ; Bin-Bin LIU ; Yuhie INAMORI ; Li YAN
Biomedical and Environmental Sciences 2007;20(6):450-455
OBJECTIVETo characterize the heterotrophic nitrifying bacteria.
METHODSThe bacteria were isolated from membrane bioreactor for treating synthetic wastewater using the method newly introduced in this study. Fluorescence in situ hybridization (FISH) was used to validate the nonexistence of autotrophic ammonia oxidizers and nitrite oxidizers. Batch tests were carried out to investigate the capability of heterotrophic nitrification by the pure culture. Phylogenetic analysis of the pure culture was performed.
RESULTSA heterotrophic nitrifier, named Bacillus sp. LY, was newly isolated from the membrane bioreactor system in which the efficiency of TN removal was up to 80%. After 24-day, incubation, the removal efficiency of COD by Bacillus sp. LY was 71.7%. The ammonium nitrogen removal rate after assimilation nearly ceased by Bacillus sp. LY was 74.7%. The phylogenetic tree of Bacillus sp. LY and the neighbouring nitrifiers were given.
CONCLUSIONSThe batch test results indicate that Bacillus sp. LY can utilize the organic carbon as the source of assimilation when it grows on glucose and ammonium chloride medium accompanying the formation of oxidized-nitrogen. It also can denitrify nitrate while nitrifying. Bacillus sp. LY may become a new bacterial resource for heterotrophic nitrification and play a bioremediation role in nutrient removal.
Bacillus ; classification ; genetics ; isolation & purification ; metabolism ; Base Sequence ; DNA Primers ; DNA, Ribosomal ; genetics ; Environmental Restoration and Remediation ; methods ; Nitrates ; metabolism ; Phylogeny ; RNA, Ribosomal, 16S ; genetics
8.Expressions of bacterial 16S rRNA, IL-1beta, TNF-alpha and NGF in prostate tissues.
Hui XIE ; Hui-Cong HUANG ; Yi-Rong YANG ; Qiu-Xiang HE ; Qi-Jian ZHU ; Jian-Ou CHEN
National Journal of Andrology 2010;16(1):40-43
OBJECTIVETo investigate the role of bacteria in the etiology of chronic prostatitis.
METHODSA total of 162 complete prostate specimens were obtained at autopsy from organ donors (aged 20 -38 yr) who died of non-prostatic diseases. Each of the samples from the peripheral zone of the prostate was divided into two parts, one for routine pathological examination and immunohistochemical studies of interleukin (IL)-1beta, tumor necrosis factor-alpha (TNF-alpha) and the nerve growth factor (NGF), and the other for PCR assay to detect the bacterial 16S rRNA gene (16S rDNA).
RESULTSFifty-one (31.5%) of the total specimens presented pathological changes of chronic prostatitis, of which 44 had mild focal stromal, 5 mild focal stromal and periglandular and 2 mild focal periglandular inflammation. The positive rate of 16S rDNA was 19.1% (31/162), 51.0% (26/51) in the chronic prostatitis and 4.5% (5/111) in the non-prostatitis specimens (chi2 = 29.783, P < 0.01). In the specimens with chronic prostatitis, the expressions of IL-1beta, TNF-alpha and NGF were significantly higher in the 16S rDNA positive than in the 16S rDNA negative group (P < 0.01).
CONCLUSIONBacterial inflammation may play an important role in the etiology of chronic prostatitis.
Adult ; Chronic Disease ; Genes, rRNA ; Humans ; Interleukin-1beta ; metabolism ; Male ; Nerve Growth Factor ; metabolism ; Prostate ; metabolism ; microbiology ; pathology ; Prostatitis ; metabolism ; microbiology ; pathology ; RNA, Bacterial ; genetics ; RNA, Ribosomal ; RNA, Ribosomal, 16S ; genetics ; Tumor Necrosis Factor-alpha ; metabolism ; Young Adult
9.Isolation and identification of a methanogen from the high temperature oil reservoir water.
Haichang LIU ; Guihong LAN ; Quanquan LIU ; Wenjing ZHANG ; Yi CAO ; Yu DENG ; Hui ZHANG
Chinese Journal of Biotechnology 2010;26(7):1009-1013
To explore new microbial resources in deep subsurface oil reservoirs, strain DL-7 was isolated with Hungate technology from oil reservoir water sampled from Dagang oilfield, China. Physiological and biochemical examinations showed that H2/CO2 is the unique substrate of the strain, which cannot metabolize formate, methanol, trimethylamine, acetate and other secondary alcohols. The optimum growth conditions were further identified to be 60 degrees C, pH 7.0-7.5 and 0.25% NaCl. Moreover, the strain cannot grow without yeast extract. Analysis of its 16S rRNA sequence indicated that a similarity of 99.7% presents between the strain and the model species M. marburgensis DSM2133T (X15364).
Hot Temperature
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Methanobacteriaceae
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classification
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genetics
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isolation & purification
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metabolism
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Methanol
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metabolism
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Methanomicrobiaceae
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genetics
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isolation & purification
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Petroleum
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microbiology
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Phylogeny
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RNA, Ribosomal, 16S
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genetics
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Water Microbiology
10.Screening and evaluation of saline-alkali-tolerant and growth-promoting bacteria.
Xue SUN ; Yonghua DONG ; Na WANG ; Wenhui CUI ; Xianyan LIAO ; Li LIU
Chinese Journal of Biotechnology 2020;36(7):1356-1364
Salinity is the most important factor for the growth of crops. It is an effective method to alleviate the toxic effect caused by salt stress using saline-alkali-tolerant and growth-promoting bacteria in agriculture. Seven salt-tolerant bacteria were screened from saline-alkali soil, and the abilities of EPS production, alkalinity reduction and IAA production of the selected strains were investigated. A dominant strain DB01 was evaluated. The abilities of EPS production, alkalinity reduction and IAA production of strain DB01 were 0.21 g/g, 8.7% and 8.97 mg/L, respectively. The isolate was identified as Halomonas aquamarina by partial sequencing analysis of its 16S rRNA genes, and had the ability to inhibit the growth of Fusarium oxysporum f. sp., Alternaria solani, Phytophthora sojae and Rhizoctonia cerealis. It also could promote root length and germination rate of wheat seedlings under salt stress. Halomonas aquamarina can provide theoretical basis for the development of soil microbial resources and the application in saline-alkali soil improvement.
Alkalies
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metabolism
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Bacteria
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drug effects
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genetics
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Halomonas
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genetics
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Plant Roots
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microbiology
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RNA, Ribosomal, 16S
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genetics
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Salt Tolerance
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genetics
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Seedlings
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growth & development
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microbiology
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Soil
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chemistry
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Soil Microbiology
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Triticum
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microbiology