The Preliminary Study on Screening and Application of Phthalic Acid-Degrading Bacteria

Phthalic acid is a main pollutant, which is also an important reason for the continuous cropping effect of tobacco. In order to degrade the phthalic acid accumulated in the environment and relieve the obstacle effect of tobacco continuous cropping caused by the accumulation of phthalic acid in the soil. In this study, phthalate degrading bacteria B3 is screened from continuous cropping tobacco soil. The results of biochemical identification and 16sDNA comparison show that the homology between degrading bacterium B3 and Enterobacter sp. is 99%. At the same time, the growth of Enterobacter hormaechei subsp. B3 and the degradation of phthalic acid under different environmental conditions are studied. The results show that the environment with a temperature of 30˚C, PH of 7, and inoculation amount of not less than 1.2%, which is the optimal growth conditions for Enterobacter sp. B3. In an environment with a concentration of phthalic acid not exceeding 500 mg/L, Enterobacter sp. B3 has a better effect on phthalic acid degradation, and the degradation rate can reach 77% in 7 d. The results of indoor potting experiments on tobacco show that the degradation rate of phthalic acid by Enterobacter B3 in the soil is about 45%, which can reduce the inhibitory effect of phthalic acid on the growth of tobacco seedlings. This study enriches the microbial resources for degrading phthalic acid and provides a theoretical basis for alleviating tobacco continuous cropping obstacles.

Isolation,Identification and Characteristics of Cellulose-degrading Bacteria

[Objectives]To isolate and identify characteristics of the cellulose-degrading bacteria.[Methods]In view of the poor effect of crop straw composting,the strains which can degrade cellulose were isolated and purified from the soil piled with rice straw,and the strains A2 and A5 with high efficiency of cellulose degradation were finally screened through the transparent circle,cellulase activity and filter paper disintegration experiments.[Results]It was confirmed that the strains A2 and A5 could degrade cellulose well.The results of 16s rDNA showed that A2 was Pseudoxanthomonas mexicana and A5 was Bacillus cibi.[Conclusions]The results of this study are expected to provide high-quality strain resources for the degradation of cellulose in straw,and have important application value for improving the efficiency of straw composting.

Antarctic Psychrophile Bacteria Screening for Oil Degradation and Their Degrading Characteristics

Two hydrocarbon degrading bacteria NJ276 and NJ341 were screened from 385 Antarctic marine bacteria and their degrading characteristics were studied. Diesel oil as sole carbon source was used in this study. The results showed that the oil degradation rates of Antarctic psychrophile bacteria NJ276 and NJ341 were 23.47 % and 32.15 %, respectively, after 20 days culturation at 5 ℃, and the rates were 43.95 % and 62.47 % respectively after 20 days culturation at 15 ℃. The oil degradation abilities were enhanced remarkably with the increasing culture temperature. GC - MSs indicated the residual oil contained C15 - C21 7 alkyls after degradation by NJ276, and C16, C17 and C18 3 alkyls after degradation by NJ341. The 16S rDNA gene sequences homology and phylogenetic analysis of the two Antarctic psychrophile bacteria showed that NJ276 belonged to the described genus Pseudoalteromonas and NJ341 belonged to the genus Colwellia.

Improvement Effect of Bioaugmentation with Phenol Degrading Bacteria on Lurgi Coal Gasification Wastewater Treatment

The improvement effect of bioaugmentation with phenol degrading bacteria( PDB) on pollutants removal and chemicals consumption was investigated in a full-scale Lurgi coal gasification wastewater( LCGW)treatment plant. Bioaugmentation with PDB applied in biological contact oxidation tank( BCOT) was carried out in summer to prevent the limitation of low temperature on the bacteria activity. After augmentation,the removal of COD and total phenol(TPh) was significantly enhanced,with efficiencies from 78.5% and 80% to 82.3% and 86.6% in BCOT,respectively. The improvement could also be detected in further processes,including anoxic-oxic,coagulation sedimentation and biological aerated filter,with COD and TPh removal efficiencies increment from 70.1%,24. 7% and 53. 4% to 73. 9%,29. 1% and 55. 9%,from 67. 1%,20% and 25% to 72.5%,25% and 32%, respectively. In addition, chemicals used for denitrification and coagulation sedimentation showed considerable reduction after bioaugmentation,with methanol,coagulant,coagulant aid and bleaching dosage from 100. 0,100. 0,80. 0 and 60. 0 mg/L to 85. 0,70. 6,57. 8 and 45.7 mg/L,respectively. Therefore,bioaugmentation with PDB can be a viable alternative for LCGW treatment plant in pollutants removal and chemicals saving.

Trifunctional Cu-Mesh/Cu_(2)O@FeO Nanoarrays for Highly Efficient Degradation of Antibiotic, Inactivation of Antibiotic-Resistant Bacteria, and Damage of Antibiotics Resistance Genes

Trifunctional Cu-mesh/Cu_(2)O@FeO nanoarrays heterostructure is designed and fabricated by integrating CuCu_(2)O@FeO nanoarrays onto Cu-mesh(CM)via an in situ growth and phase transformation process.It is successfully applied to efficiently mitigate the antibiotic pollution,including degradation of antibiotics,inactivation of antibiotic-resistant bacteria(ARB),and damage of antibiotics resistance genes(ARGs).Under visible-light irradiation,CM/CuCu_(2)O@FeO nanoarrays exhibit a superior degradation efficiency on antibiotics(e.g.,up to 99%in 25 min for tetracycline hydrochloride,TC),due to the generated reactive oxygen species(ROS),especially the dominant·O^(2−).It can fully inactivate E.coli(HB101)with initial number of~108 CFU mL^(−1) in 10 min,which is mainly attributed to the synergistic effects of 1D nanostructure,dissolved metal ions,and generated ROS.Meanwhile,it is able to damage ARGs after 180 min of photodegradation,including tetA(vs TC)of 3.3 log 10,aphA(vs kanamycin sulfate,KAN)of 3.4 log 10,and tnpA(vs ampicillin,AMP)of 4.4 log 10,respectively.This work explores a green way for treating antibiotic pollution under visible light.

Hydrocarbon-Degrading Bacteria and Paraffin from Polluted Seashores 9 Years after the Nakhodka Oil Spill in the Sea of Japan

Pollution of petroleum hydrocarbons, in particular oil spills, has attracted much attention in the past and recent decades. Oil spills influence natural microbial community, and physical and chemical properties of the affected sites. The biodegradation of hydrocarbons by microorganisms is one of the primary ways by which oil spill is eliminated from contaminated sites. One such spill was that of the Russian tanker the Nakhodka that spilled heavy oil into the Sea of Japan on January 2, 1997. The impact of the Nakhodka oil spill resulted in a viscous sticky fluid fouling the shores and affected natural ecosystems. This paper describes the weathering of hydrocarbon-degrading bacteria （genus Pseudomonas） and crystallized organic compounds from the Nakhodka oil spill-polluted seashores after nine years. The Nakhodka oil has hardened and formed crust of crystalline paraffin wax as shown by XRD analysis （0.422, 0.377, and 0.250 nm d-spacing） in association with graphite and calcite after 9 years of bioremediation. Anaerobic reverse side of the oil crust contained numerous coccus typed bacteria associated with halite. The finding of hydrocarbon-degrading bacteria and paraffin wax in the oil crust may have a significant effect on the weathering processes of the Nakhodka oil spill during the 9- year bioremediation.

Cultivating High Efficient Bacteria of Degrading Pulping Wastewater by Ultraviolet Mutagenic Technology

Instead of pure bacteria, induction mutation of activated sludge by ultraviolet (Uv) was studied and used to treat pulping wastewater by continuous- flow. The result showed the mutagenic activated sludge had remarkable effect and application potential in pulping wastewater treatment. Comparing with common activated sludge, the mutagenic activated sludge was more suitable for lignose decomposition and had high decomposing efficiency.

A Feasible Way of Degrading Malathion Pesticide under Laboratory Condition Using Phosphate Solubilizing Bacteria

An experiment was carried out for identification and determination of malathion degrading phosphate solubilizing bacteria isolated from the agricultural fields. In this study, malathion degrading phosphate solubilizing bacteria were identified using NBRIP (National Botanical Research Institute’s phosphate growth medium) media. A number of bacterial colonies were screened from agricultural fields. From primarily screened colonies 4 isolates were identified as phosphate solubilizing bacteria through qualitative and quantitative analysis. The isolated 4 bacterial colonies were inoculated in NBRIP broth media enriched with malathion pesticides to observe degradation of malathion pesticide under incubation study at three different temperatures (25°C, 30°C and 37°C). However, all the four isolates showed capability in degrading malathion pesticide. The study clearly revealed that phosphate solubilizing bacteria can be used in bioremediation of environmental pollution caused by malathion pesticide.

Phylogenetically diverse,acetaldehyde-degrading bacterial community in the deep sea water of the West Pacific Ocean

As a major aldehyde pollutant widely existing in industry and our daily life, acetaldehyde is more and more harmful to human health. As characteristic habitat niche, bacteria from deep sea environments are abundant and distinctive in heredity, physiology and ecological functions. Thus, the development of acetaldehyde-degrading bacteria from deep sea provides a new method to harness acetaldehyde pollutant. Firstly, in this study,acetaldehyde-degrading bacteria in the deep sea water of the West Pacific Ocean were enriched in situ and in the laboratory respectively, and then the diversity of uncultured bacteria was studied by using 16 S r RNA genes. Then acetaldehyde-degrading strains were isolated from two samples, including enrichment in situ and enrichment in laboratory samples of deep sea water from the West Pacific Ocean using acetaldehyde as the sole carbon source,and then the ability of acetaldehyde degradation was detected. Our results showed that the main uncultured bacteria of two samples with different enrichment approaches were similar, including Proteobacteria,Actinobacteria, Firmicutes, Cyanobacteria, but the structure of bacterial community were significant different.Four subgroups, α, γ, δ and ε, were found in Proteobacteria group. The γ-Proteobacteria was dominant（63.5%clones in laboratory enriched sample, 75% clones in situ enriched sample）. The species belonged to γ-Proteobacteria and their proportion was nearly identical between the two enrichment samples, and Vibrio was the predominant genus（45% in laboratory enriched sample, 48.5% in situ enriched sample）, followed by Halomonas（9% in situ enriched sample） and Streptococcus（6% in laboratory enriched sample）. A total of 12 acetaldehyde-degrading strains were isolated from the two samples, which belonged to Vibrio, Halomonas,Pseudoalteromonas, Pseudomonas and Bacillus of γ-Proteobacteria. Strains ACH-L-5, ACH-L-8 and ACH-S-12,belonging to Vibrio and Halomonas, have strong ability of acetaldehyde degradation, which could tolerate 1.5 g/L acetaldehyde and degrade 350 mg/L acetaldehyde within 24 hours. Our results indicated that bacteria of γ-Proteobacteria may play an important role in carbon cycle of deep sea environments, especial the bacteria belonging to Vibrio and Halomonas and these strains was suggested for their potentials in government of aldehyde pollutants.

Mineralization of Petroleum Contaminated Wastewater by Co-Culture of Petroleum-Degrading Bacterial Community and Biosurfactant-Producing Bacterium

Activity of a crude biosurfactant extracted from the culture fluid of Serratia sp. that was isolated from riverbed soil was shown to increase in proportion to the cultivation time, and was higher at pH 8 than at pH 7. Serratia sp. grew in the mineral-based medium with soybean oil but was not with kerosene-diesel. The petroleum-degrading bacteria—Acinetobacter sp., Pseudomonas sp., Paracoccus sp., and Cupriavidus sp.—were isolated from a specially designed enrichment culture. The efficiency of mineralization of wastewater contaminated with kerosene and diesel (WKD) by the petroleum-degrading bacterial community (PDBC) was enhanced significantly by addition of the crude biosurfactant. The efficiency of mineralization of the WKD was also about 2 times boosted by co-culture of Serratia sp. and PDBC. Bacterial community of Serratia sp. and PDBC co-cultivated in the WKD was maintained for at least 8 days according to the TGGE pattern of 16S rDNA obtained from the bacterial culture. In conclusion, the co-culture of Serratia sp. and PDBC is an applicable technique for the mineralization of wastewater contaminated with petroleum, which may substitute for chemical or biological surfactant.

Cumulative Toxicity of Residue Degradation Products of Penicillin Bacteria

[Objective] The research aimed to discuss the accumulation of toxic slag of penicillin bacteria residue degradation products and explore its ability to meet the aquaculture industry as a protein feed into development and utilization conditions.[Method] Through the sub-acute toxicity tests in mice strains,which were fed by different doses of penicillin bacteria residue degradation products （3% and 6%） under continuous observation of 15 weeks,recording a weekly mouse weight and death,and sampling executed after the test,animal liver and kidney function were blood test,taking heart,liver,spleen,kidney weighing,as well as liver and kidney pathology observed in the optical microscope.[Result] There were no significant differences （P 0.05） between the test group mice body weight,mortality and liver and kidney function and the control group within 15 weeks.Low-dose test group could be seen the liver cells,renal tubular epithelial nuclei broken,and a small number of liver and kidney cells with mild edema.High-dose test group could be seen in liver tissue of mice nuclei fragmentation and a fat droplets,the majority of liver cells,edema,and only a small number of liver cells,there were no significant changes.Renal portal area showed inflammatory cell infiltration,renal tubular epithelial cells,edema and necrosis.[Conclusion] In this experimental condition,the degradation products of penicillin bacteria residue played a mild toxcity on organ parenchymal cells in mice.

Aromatic compound degradation by iron reducing bacteria isolated from irrigated tropical paddy soils

Forty-six candidate phenol/benzoate degrading-iron reducing bacteria were isolated from long term irrigated tropical paddy soils by enrichment procedures.Pure cultures and some prepared mixed cultures were examined for ferric oxide reduction and phenol/benzoate degradation.All the isolates were iron reducers,but only 56.5%could couple iron reduction to phenol and/or benzoate degradation,as evidenced by depletion of phenol and benzoate after one week incubation.Analysis of degradative capability using Biolog...

Straw bio-degradation by acidogenic bacteria and composite fungi

A composite microbial system, including a strain of Candida tropicalis(W3), a strain of Lactobacillus plantarm(WY3) and three strains of basidiomycete pL104, pL113 and C33, was chosen to degrade corn straw. The final pH was acid owing to the inoculation of acidogenic bacteria, and under this condition the composite fungi system could produce complex enzyme to destroy the compact structure of corn straw. The experimental results showed that the biomass of composite fungi could reach up to maximum when the pH value was 4.5. Through the bio-degradation by combining acidogenic bacteria with the composite fungi system, the cellulose, hemi-cellulose and lignin degradation rates of corn straw powder were 26.36%, 43.30% and 26.96%, respectively. And the gross crude protein content increased 60.41%. This study provided the evidence for the feasibility of developing a composite microbial system with high capability of degrading straw lignocelluloses in order to make reasonable use of straw resource and protect rural eco-environment.

Exploring the Degradation Potential of Halomonas Bacteria from Oil-contaminated Marine Environment

The degradation potential of a diesel-degrading bacteria(HDMP1) isolated from the oil-contaminated marine environment was explored systematically by analyzing the environmental conditions and synergistic action with other dieseldegrading bacteria. The result indicated that HDMP1 was confirmed as a strain of Halomonas by the method of strain identification. And, HDMP1 showed good diesel degradation performance with a diesel degradation rate of up to 79.59%after 7 days. By analyzing the effect of environmental conditions on HDMP1, the best carbon and nitrogen sources were found to be lactose and peptone, respectively, at a pH value of 7.5 and a salinity of 4 g/(100 mL). Additionally, the synergistic effect of HDMP1 combined with other diesel-degrading bacteria was analyzed by orthogonal experimental design. The inocula of HDMP1, HDMP2, HDMP3 and HDMB3 were optimized, with the best results equating to 0.4%, 0.1%, 0.4% and0.9% in 100 mL of MSM, respectively, while the degradation rate of diesel was identified to be 73.5% within 5 days in the presence of optimum inocula.

Wetland bacteria isolated from Huangpu River-Yangtze River estuary and its degradation on diesel

Oil contaminated soil was collected from Huangpu River-Yangtze River estuary wetland, with the aim of isolating oil-degrading microorganisms and evaluating their ability to degrade diesel. Three bacterial strains were discovered and identified by sequencing their 16S rDNA genes, two were Pseudomonas and one was Alcaligcnes. The proper growth conditions of each bacterium were measured and presented for diesel biodegradation. Biodegradation assays revealed that the degradation rates of three bacterial strains were 42.5%, 14.6% and 15.9% in 7 d respectively. They all play an important role on the nalkanes within the range of C16-C25 components of diesel. The results indicated that the oil-degraders can adapt to degrade diesel. The bacterial strains can be used in wetland diesel pollution control.

Effects of different acclimations on high solution bacteria in coal-gas wastewater degradation

To make microbial community be applied more easily in practical biotreatment engineering,three acclimation processes were carried out in lab scale. Three kinds of mixed microorganism cultures with degradability for a gas-making plant wastewater were obtained. The degradation experiments results of coal-gas wastewater indicated that different acclimation processes had obviously impacted on degradability of microbial community,and under high sludge loading rate,mixed microorganism cultureⅠ(obtained by H.S.B as bacteria source and raw wastewater as alone carbon and energy source)presented stronger degradability for coal gasification wastewater than the others. COD removal rate of mixed cultureⅠcan reach 57.6% under very low MLSS when the influent COD is 900 mg/L. Meanwhile,the results of microscopic examination showed that Protozoa,mainly epistylis and Vorticella species,were stronger activity and larger quantities in mixed cultureⅠ.

Degradation Performance and Biodiversity of an Anaerobic Polyvinyl Alcohol-Degrading Microbial Community

Polyvinyl alcohol( PVA) is a water-soluble synthetic polymer that is hard to biodegrade. PVA-degrading microorganisms were previously reported as unitary bacteria and most of them have been identified as aerobes. In this work,a microbial community was cultured anaerobically and its degradation performance and biodiversity were analyzed. The microbial community was cultured for more than 40 d,which represents a highly efficient degradation performance with a chemical oxygen demand removal efficiency of 88. 48%. Operational taxonomic unit-based analysis of the sequences revealed a highly diverse community in the reactor. To note,metagenome 16s rDNA sequencing delineated 19 phyla and 41 classes. Specifically, proteobacteria, chlamydiae, bacteroidetes,firmicutes,and planctomycetes play key roles in the biodegradation processes. Moreover,the betaproteobacteria class belonging to the proteobacteria phylum was the predominant bacterial members in this community. Our results demonstrated that anaerobic treatment of PVA wastewater is feasible and confers degradation by a highly diverse microbial community.

Evaluation of the Biotechnological Potential of Isolated Bacteria of the Soil in the Degradation of Residues of Skin Swine

The degradation of industrial residues is of great importance for the maintenance of the environment. Therefore, the objective of this study is to verify the proteases production for bacteria of the gender isolated Bacillus of soil. The samples of skin residue were collected in industries of the area west of Santa Catarina, using residue of skin rude swine and residue of skin processed swine. The verification of the biotechnological potential consisted of the use of these residues in middle of culture and inoculation of the respective species of bacteria. The results were more expressive in the samples of skin processed swine, where it showed a degradation average around 43.55% (p/p). While, in the samples of residue of skin rude swine, an average of degradation of 20.60% (p/p) happened. In this way, the residue of skin processed swine is more sensitive than the catalytic activity of the bacterial enzymes.

Application of Uniform Design and SVR for Culture Medium Optimization of Organophosphorus Degradation Bacteria

In order to improve the degradation activity of organophosphorus degradation bacterial strains, uniform design and support vector regression(SVR) are used to optimize the formula of mineral salt medium for the strains based on single factor experiment. The formula being used after SVR optimization is glucose 1.24 g/L,NH4 NO3 0.73 g, KH2 PO4 0.96 g, KCl 0.50 g, MgSO4·7 H2 O 0.50 g, MnSO4 0.02 g, CaCl2 0.04 g, distilled water 1 000 mL;the highest degradation rate is obtained at pH7.0(SVR, 76.68%), superior to that of the QSAR model(74.67%). The formula optimization method based on uniform design and SVR is very promising to apply in various multiple-factor and multiple-level formula optimization experiments.

全面供光策略调控废水培养光合细菌产单细胞蛋白

为拓展蛋白质来源,缓解中国饲料蛋白资源短缺现状,该研究通过供光策略调控强化了沼泽红假单胞菌(R.palustris)从废水中回收菌体资源及单细胞蛋白(single cell protein, SCP)的效果,并解析了不同供光策略下物质合成与污染物降解之间的相关性。结果表明:在白炽灯、120μmol/(m^(2)·s)的光强及18 h光/6 h暗(L/D)的光周期条件下菌体的生物量及日产量可达(1 140.56±19.72) mg/L及(0.32±0.02) g/(L·d),相较于24 L/0 D、 3 L/21 D及9 L/15 D组分别提高了17.06%~93.21%、54.43%~299.93%(P<0.05);在白炽灯、120 μmol/(m^(2)·s)的光强及3 h光/21 h暗的光周期条件下,菌体的蛋白质质量分数最高,为67.47%,相较于其他所有试验组提高了21.96%~44.54%(P<0.05)。化学需氧量(chemical oxygen demand, COD)和氨氮(ammonia nitrogen, NH_(4)^(+)-N)去除率在白炽灯、120 μmol/(m^(2)·s)的光强及18 h光/6 h暗的光周期条件下可达72.03%~78.40%。相关性分析表明,光强、光质分别与蛋白质含量及浓度呈显著负相关;而光周期与蛋白质浓度呈显著正相关,因此,光周期是R. palustris从废水体系中提升SCP产量的有效调控方法。该研究为提高废水体系中光合细菌合成SCP提供了新的方法与思路。