Abstract:To obtain cellulose-decomposing strains, and to use them for decomposition of rice straw and rice hull. A cellulose-decomposing strain YN1 was isolated from cattle and sheep feces compost. Strain YN1 was identified by morphologic and phylogenetic analysis. Moreover, we performed the liquid and solid fermentation of YN1, and the degrading test of cellulose. In addition, scan electron microscope was used to observe the fixed propagation of YN1 on the cellulose and cellulose degradation. The morphologic and ITS gene sequence analysis suggested that YN1 was Aspergillus sp.. Through liquid fermentation, endoglucanases, exoglucanases, beta-glucosidases and the total cellulase activities reached to maximum at the 3th day, and they were 95.7, 14.6, 20.5 and 26.6 U/mL respectively. Though solid fermentation, the 4 kinds of cellulase activities reached to maximum at the 5th day, and they were 1192.2, 100.6, 136.9 and 210.7 U/g respectively. In the degrading experiment, YN1 could degrade 41.87% of rice straw, 31.59% of rice hull in weight in 7 days respectively. The remarkable phenomenon that YN1 degrading crude cellulose could be observed by scan electron microscope. YN1 showed value of practical applications in rice straw and rice hull decomposition.

Abstract:To research the effect of nitrogen-fixing bacteria on grow of cotton, we used the technique of ERIC-PCR and 16S rDNA sequencing analysis to study genetic diversity of 58 nitrogen-fixing bacteria isolated from Tarim cotton soils in Xinjiang province. Cluster analysis was used for ERIC-PCR results of these strains by UPGMA. The results showed that the tested strains formed 9 clusters when the Waston distance was about 0.65. The typic strains of 9 clusters were identified as Enterobacter, Bacillus, Acinetobacter, Pseudomonas, Serratia, Yersinia by 16S rRNA sequencing analysis.

Abstract:Methanogenic diversity was characterized in an anaerobic digester with chicken feces by using a culture-independent approach. 50 clones of a 16S rDNA gene library were randomly selected and their sequences were phylogenetically analyzed. 46 of them (92%) was determined belonging to Methanogenium with similarities to Methanogenium marinum strain AK-1 between 99% to 100%; 3 clones (6%), KD525, KD526, and KD567, belonging to Methanoculleus with similarities 99% to Methanoculleus sp. dm2; one clone (2%), KD519, belonging to Methanocorpusculum with a similarity 99% to Methanocorpusculum bavaricum. Further more, the phylogenetic analyse of alpha subunit A of methyl-coenzyme M reductase (mcrA) clones were also performed. Gas chromatography assay showed that the content of formic acid was 28.85 g/L, 81.7% of the total volatile fatty acid of the fresh fermentation slurry; and the produced biogas from the digester was also determined, mainly composing of methane (55.5%), carbon dioxide (41.1%), and hydrogen (3.2%).

Abstract:A composite microbial system MEG with high efficient and stable degradation of cotton stalks was screened through the method of multigeneration selection. This microbial system was inoculated to the cotton stalks, and then stationarily treated for 7 days. Afterwards, biogas fermentation was conducted. Compared to the condition of non-pretreatment, the gas production increased by 25%. DGGE analysis showed that the diversity of bacterial community structure in the biogas fermentation system of cotton stalks was more abundant compared to the condition of non-pretreatment. At the same time, comparison in the effects of inocula obtained from 6 kinds of domestication methods on daily and cumulative of biogas production of cotton stalks was conducted. The results showed that the inocula domesticated from the mixture of 5 kinds of activated sludge from river bed mud, sewage ditch, industrial wastewater bed, pond bed, and lake bed could be acted as effective inocula for biogas fermentation of cotton stalks. The daily gas production and cumulative gas production were higher compared to the inocula domesticated from one kind of activated sludge.

Abstract:This paper discusses the use of ultraviolet mutagenesis combined chemostat enrichment method to screen high-temperature resistent and high-yield lactic acid bacteria. Firstly, treated a strain of Lactobacillus rhamnosus with ultraviolet rays as mutagen, and then, before plate screening, used the chemostat continuous culture method to enrich high-temperature resistent and high-yield strains at 55oC. At last we obtained nine high-temperature strains. When fermented at 55oC, the highest production of L-Lactic acid was 62.9 g/L in 48 hours, which was 18.1 g/L higher than the starting strain. It was found that this method was more efficient than direct plate screening method by a comparing experiment, greatly reducing the workload of re-screening.

Abstract:A cellulose degrading strain DSH was isolated from the sediment of Dianshan Lake, Huangpu River, Shanghai. Basing on morphology, biochemical and physiological characterization, DSH was characterized as Bacillus cereus. A phylogenetic tree was constructed with the published 16S rRNA sequences of relative bacteria species. In the phylogenetic tree, the DSH strain is in a new branch which has the closest relative to Bacillus cereus strain JBE0004 with 99.78% sequence similarity. The generation of cellulose was closely correlated to its growth rate. The highest cellulose activity of DSH strain was 4.58 U/mL when grown at 37oC, pH 7.0 for 66 h.

Abstract:The major organic acids produced in the fermentative hydrogen production by mixed cultures were acetic acid, propionic acid, lactate acid and butyric acid, etc. which had negative effect on hydrogen production. The acid tolerance of mixed cultures was improved by the metabolites stress and the sludge activities under different stresses were investigated through the dehydrogenase activity (DHA) determination in the work. The results showed that certain metabolite stress could increase the hydrogen production and the metabolite yield, especially when acetic acid and butyric acid were used for stress. Importantly, the cumulative hydrogen quantity nearly doubled compared with the control. Interestingly, the acetic acid production enhanced extensively regardless of the stress method of all groups.

Abstract:第十二次全国环境微生物学术研讨会于2009年11月在武汉华中科技大学顺利召开, 本次会议围绕“环境微生物与人类健康”的主题, 在环境微生物学前沿、微生物与环境健康及人类健康、环境微生物资源挖掘与利用, 以及环境微生物技术与环境污染防治、生态修复、废弃物资源化利用和再生能源等诸多领域展开深入研讨, 充分反映了我国环境微生物学界取得的最新进展, 为了展现国内环境微生物及相关交叉领域科研工作者取得的最新进展, 《微生物学通报》针对“第十二次全国环境微生物学术研讨会”组织出版了这期“环境微生物专刊”, 期望该专刊的出版有助于促进我国环境微生物学相关领域的交流和发展。

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Abstract:Native Acidithiobacillus ferrooxidans (A. f) and Acidithiobacillus thiooxidans (A. t) were isolated from excess activated sludge. Mixed and single cultures of them were used to bioleach for 9 days to remove heavy metals from activated sludge. The changes of pH and ORP (Oxidation Reduction Potential) were measured every day. Also, the changes of concentrations for heavy metals were measured. Results showed that the removing rate for mixed culture was the best in all runs. The removing rate for As, Cr, Cu, Ni, Zn is 96.09%, 93.47%, 98.32%, 97.88%, 98.60% respectively. The removing rate of Cd and Pb for mixed culture decreased rapidly after six days. However, the rates of removing Cd and Pb remained higher levels after leaching for 6 days by Acidithiobacillus thiooxidans.

Abstract:The continous cropping obstacle widely exists in cash crop cultivation, which usually result in a decline of the crop yield and quality. The origin of continous cropping obstacle is close related with the shift in soil environment, and the evolve of soil microorganism in continous cropping was important. This paper studied the effect of continous cropping on the rhizosphere bacterial using liriope (Liriope spicata var. prolifera Y. T.) as testing mertials. The diversity of liriope rhizosphere microbial communities was investigated by PCR-DGGE, the Shannon-Weaver indices of the continous cropping liriope rhizosphere microbial communities were 3.36-3.40-3.69 from seedling stage to rapid growing stage and to earthnut intumescentia stage, the richness indices were 55.0-61.5-63.5, the evenness indices were 0.84-0.82-0.89, those indices of normal liriope rhizosphere were 3.66-3.33-3.72, 67.5-53.5-63.5, and 0.87-0.84-0.90, respectively. The result shown that the trend of rhizosphere bacterial communities diversity variation in the continous cropping liriope was different with normal liriope. Furthermore, the Principal Components Analysis of DGGE profile of rhizosphere bacterial communities shown that the components of bacterial communities in continous cropping liriope were separated from normal liriope. That suggested continous cropping could alter the diversity variation trend and components of rhizosphere bacterial communities. Comparing the quantity of soil function bacteria at liriope tuberous intumescentia stage, the amount of amonifying bacteria and cellulose decomposition bacteria were increased while nitrobacteria and azotobacter were significant decreased after continous cropping. Besides, the yield of continous cropping was 70.6% of normal, it indicated that the decline in yield of liriope in continous cropping was related to the vary of soil bacterial community.

Abstract:Amorphophallus konjac, rich in konjac glucomannan and many other active components, has been used widely in food, medicine and biochemical field. However, konjac diseases caused by Erwinia bacterium become more and more serious, which is a devastating catastrophe to konjac production. Therefore, it is necessary to study the pathogenesis of konjac’s soft rot disease. In the present study, it mainly focused on the infection conditions and factors of the Erwinia bacterium. The main results showed that the appropriate temperature and humidity for infection was 25oC-30oC and 90%-95%, respectively. When the konjac was badly decomposed, the activities of cell wall-degrading enzymes including pectinase and cellulase increased rapidly, which reached the maximum value of 1.2473 U/mg on the 6 days and 1.0813 U/mg on the 9 days, respectively. The results indicated that the pectinase and cellulase were both important during the infection.

Abstract:Screening seven strains of efficient phenol degradation bacterium in activated sludge from Harbin Taiping sewage treatment plant. These strains can use phenol as the only available carbon sources and energy. Based on inspects the growth and degradation of phenol in different temperature, pH value, and different phenol concentration. We can determine that the optimal temperature of seven bacterias is 10oC, the optimal pH value is 7.5, the lagest concentration of degradation of phenol is 3000 mg/L. From the study of degradation performance by these seven bacteriums shows that it has strong ability of phenol degradation. In the condition of 10°C, pH 7.5, fluid for 50 mL, vaccination is 15%, vibration velocity wave 160 r/min, degradation rate of 500 mg/L phenol can reach more than 90% after 48 h in the training. Glucose to the growth of bacteria and phenol degradation ability all have certain effects, when glucose concentration is 500 mg/L, the degradation rate of phenol is still more than 80%. The study on treatment contain other carbon sources of hydroxyl benzene wastewater has certain significance. Through the analysis DGGE strip map shows that the brightness can explain these bacteria are advantage bacterium in each system, and strong activityin sewage, its dominant position can be exist steadily. Rich strips are 2, 4, 24, 28, and it is showing its diversity in sewage system.

Abstract:At the present time, probiotics used in recovering sea culture wastewater has some defects, such as no good counter, adaptation and relationship of these strains, so the applying effect is not satisfying. In our experiment, nitrosobacteria ZW38, denitrobacteria ZL5 and secreting proteinase strain ZS7, which were isolated from wastewater of marine culture, were mixed according the nitrogen cycle of seawater culture, the number of various strain and the content of NH4-N, NO2-N were determined. The results showed that these strains grow well each other when the ratio of ZW38, ZL5 and ZS7 is 3:2:1, and the total inoculating numer is 109 CFU/L. After 5 d for treating, the decomposed rate of resoluble protein and NH4-N is 94.0% and 77.5% respectively.

Abstract:A new kind of high flocculants-producing bacteria JX18 was isolated from sludge samples. It was identified as a Pseudomonas fluorescens based on its morphological, physiological characteristics and the partial sequences of its 16S rRNA. The bacteria reached stationary phase after culturing 40 h, and had a maximum ?occulating activity after culturing 48 h. The further investigation indicated that the optimum flocculants-producing conditions obtained were initial pH 7.0, temperature 30oC, rotation speed 160 r/min, glucose and peptone were chosen as the optimum carbon and nitrogen sources. Optimum cultivation conditions, the flocculation efficiency toward a gaolin clay suspension reached 90.56%.

Abstract:Influences of several different kinds of flocculating agent on photosynthetic bacteria Rhodobacter sphaeroides were assessed by analyzing settling performances and strength of bioflocculates. From the results, polychlorinated alumina (PAC) was finally selected as a flocculating agent to accelerate formation of granular sludge of Rhodobacter sphaeroides. Tests gave the dose of PAC in the range of 140-160 mg/L. When the dose of PAC was 150 mg/L, granulation was the most effective. The degradation efficiency and reaction parameters were investigated on treating chlorobenzene in water by granular sludge of Rhodobacter sphaeroides. The results showed that the optimal conditions of treatment for chlorobenzene in water by granular sludge of Rhodobacter sphaeroides were aerobic condition, temperature 30oC and pH 7.0.

Abstract:De-odorizing microbe F468 was used to reduce N nutrient losses and enhance the innocuous process of chicken manures. From its 1st to 80th subculture cycle, F468 showed stable ability to reduce NH3 emission from chicken manures. The total N nutrient losses were reduced by 79% by the addition of F468, compared with that without F468. Moreover, F468 could accelerate the innocent process of chicken manures by reducing Ascaris eggs and Fecal coliforms. Without adding F468, it took 25 days and 20 days for the dead rate of Ascaris eggs and the number of Fecal coliforms in chicken manure to reach the national standard of NY884-2004, respectively. While adding F468, it took 15 days and 10 days for the dead rate of Ascaris eggs and the number of Fecal coliforms to reach the national standard, respectively.

Abstract:A bacterial strain ADZ1 that demonstrated higher efficient in the aerobic denitrification was isolated from the sewage of urban rivers on the selective medium, Bromothymol Blue (BTB), after enriched in the shaking flasks. The reduction efficiency for nitrate and the total nitrogen reached 93.1% and 34.7% within 48 hours respectively. Sequence of 16S rRNA suggested that strain ADZ1 belongs to the genus of Pseudamonas, and further was identified as Pseudomonas putida by VITE K? 2 systems. With the growth conditions that the ethanol served as the carbon source and C/N ratio was 12:1, the efficiency for nitrate and the total nitrogen reduction reached 98% and 41.3% respectively. Due to the broad adaptability to dissolved oxygen and pH, together with the high activity for aerobic denitrification, this strain showed the potential application in the future.

Abstract:Five manganese-resistant and manganese-removing bacterial strains were isolated from soil samples of a Zn-Mn mine in Hunan and manganese storage of Xi Qingma steel factory in Tianjin and named as J2-3, J4-3, J12-1, JM3-2 and JD. Based on morphological, physiological/biochemical tests and 16S rRNA gene analysis, these strains were identified as Hydrogenophaga, Mycobacterium, Rhodococcus, Acinetobacter and Bacillus respectively. The minimal inhibitory concentration (MIC) of JM3-2 and JD were 2 mmol/L while MIC of J2-3, J4-3, and J12-1 reached 12 mmol/L. The X-ray diffraction analysis showed that the precipitate formed by the Mn(Ⅱ)-removal bacteria was MnCO3. All of the 5 strains could remove manganese effectively ( > 85%). Strains JD and JM3-2 removed 94.28% ± 0.1% and 93.10% ± 3.1% Mn(Ⅱ) from the medium, respectively. During the removing process, the pH increased from 7.0 to more than 8.5. This indicated the mechanism of manganese removing may caused by the metabolism of the Mn(Ⅱ)-removing bacteria to transform of soluble Mn(Ⅱ) into the insoluble MnCO3 when pH increased. Here we report a new-type of manganese-removing bacteria, which is different from the maganese-oxidizing bacteria reported before.

Abstract:Growth and de-emulsification efficiency of Bacillus subtilis under different carbon and nitrogen sources were investigated. The fermentation conditions were also optimized with orthogonal tests. The results showed that medium containing glucose as sole carbon source and compound medium containing glucose and liquid paraffin as carbon sources could enhance the fermentation production of the Bacillus subtilis. Higher de-emulsification efficiency was obtain with medium utilized glucose as sole carbon source, compound medium utilizes glucose and gasoline as carbon source as well as medium utilized ammonium nitrate and yeast extract as nitrogen sources. The orthogonal tests showed that the incubation temperature was the most influential factor for the fermentation production of the Bacillus subtilis. The optimal combination for fementation was as follows: incubation temperature 25oC, shaker revolution 140 r/min, pH 7.0, inoculum concentration 6 mL and incubation time 24 h. The most influential factor for the de-emulsification efficiency of the fermentation products of the Bacillus subtilis’s fermentation products was the shaker revolution. The optimal combination for de-emulsification efficiency was as follows: incubation temperature 25oC, shaker revolution 140 r/min, pH 7.0 and incubation time 24 h.

Abstract:Nitrite (NO2-) exists in the biological phosphorus and nitrogen removal system as an intermediate in the biological oxidation of ammonia to nitrate and reduction of nitrate to nitrogen. In enhanced biological phosphorus removal (EBPR) processes, nitrite is an electron acceptor used by denitrifying phosphorous removal bacteria and also an inhibitor to biological phosphorus removal process. This paper reviews metabolic mechanism of phosphorus accumulating organisms (PAOs) under anaerobic, aerobic and anoxic conditions separately. The effect of nitrite on biological phosphorus removal as well as inhibition mechanism of nitrite was introduced. The personal opinions were also suggested.

Abstract:Sulfonylurea herbicides are a kind of high efficiency, low toxicity and good crop selective herbicides, such herbicides can be used to control of broadleaf weeds effectively, some varieties even can inhibit grass weeds efficiently. Because of this class herbicides’ residual toxicity to crop rotation and also to surface water, thus people should pay more attention to their persistence and environmental safety. This paper reviews the general application, the mode of action of sulfonylurea herbicides and the variety of microorganisms capable of degrading sulfonylurea herbicides, the factors that affect the efficiency of microbial degradation, finally prospect that the best ways to resolve herbicide residues are microbial remediation technology and herbicide-resistant transgenic crops.

Abstract:Rhizobia, which are symbiotes of leguminous plants, are of considerable environmental and agricultural importance due to their nitrogen fixation properties. With the development of new molecular biological techniques, new methods are applied to the rhizobia classification, with the polyphasic approach being the most reliable. This advancement has led to the reorganization of already classified species of rhizobia, as well as to the identification of new species from an array of as yet unexplored legume plants from various environments. Here we discuss the progress made in the evolutionary systematics of Rhizobia, as well as the disputes associated therewith.

Abstract:Adsorption of bacteria to mineral surface is the premise of deep interaction of bacteria and mineral, and is also the fundamental application research of bacteria in mineral processing as reagents. The environmental factors influencing adsorption of bacteria to mineral surface, interaction between bacteria and mineral, effect of bacterial surface groups, surface components and its extracellular polymer substance on adsorption were summarized in this article, and the research direction of microbe applying in mineral processing is proposed.