共查询到20条相似文献,搜索用时 31 毫秒
1.
Abhay Raj Ram Chandra M.M.K. Reddy Hemant J. Purohit Atya Kapley 《World journal of microbiology & biotechnology》2007,23(6):793-799
A kraft lignin-degrading bacterium (ITRC S
7
) was isolated from sludge of pulp and paper mill and characterized as Aneurinibacillus aneurinilyticus by biochemical tests and 16SrRNA gene sequencing. The bacterium did not utilize kraft lignin (KL) as the sole source of carbon
and energy. However, this strain reduced the color (58%) and lignin content (43%) from kraft lignin-mineral salt medium when
supplemented with glucose at pH 7.6 and 30°C after 6 days. The degradation on addition of glucose in culture medium is clear
evidence of co-metabolism of KL by A. aneurinilyticus. The analysis of lignin degradation products by GC-MS in ethyl acetate extract from an A. aneurinilyticus-inoculated sample revealed the formation of low molecular weight aromatic compounds such as guaiacol, acetoguaiacone, gallic
acid and ferulic acid, indicating that the bacterium can oxidize of the sinapylic (G units) and coniferylic (S units) alcohol
units which are the basic moieties that build the hardwood lignin structure. The low molecular weight aromatic compounds identified
in extracts of the inoculated sample favors the idea of biochemical modification of the KL to a single aromatic unit. 相似文献
2.
Xinghui Qiu Qiuzan Zhong Mei Li Wenqin Bai Baotong Li 《International biodeterioration & biodegradation》2007,59(4):297-301
Ochrobactrum sp. B2, a methyl parathion-degrading bacterium, was proved to be capable of using p-nitrophenol (PNP) as carbon and energy source. The effect of factors, such as temperature, pH value, and nutrition, on the growth of Ochrobactrum sp. B2 and its ability to degrade p-nitrophenol (PNP) at a higher concentration (100 mg l−1) was investigated in this study.The greatest growth of B2 was observed at a temperature of 30 °C and alkaline pH (pH 9–10). pH condition was proved to be a crucial factor affecting PNP degradation. Enhanced growth of B2 or PNP degradation was consistent with the increase of pH in the minimal medium, and acidic pH (6.0) did not support PNP degradation. Addition of glucose (0.05%, 0.1%) decreased the rate of PNP degradation even if increased cell growth occurred. Addition of supplemental inorganic nitrogen (ammonium chloride or ammonium sulphate) inhibited PNP degradation, whereas organic nitrogen (peptone, yeast extract, urea) accelerated degradation. 相似文献
3.
M. Vidyasagar S. Prakash S. K. Jayalakshmi K. Sreeramulu 《World journal of microbiology & biotechnology》2007,23(5):655-662
An extremely halophilic Chromohalobacter sp. TVSP101 was isolated from solar salterns and screened for the production of extracellular halothermophilic protease.
Identification of the bacterium was done based upon biochemical tests and the 16S rRNA sequence. The partially purified enzyme
displayed maximum activity at pH 8 and required 4.5 M of NaCl for optimum proteolytic activity. In addition, this enzyme was
thermophilic and active in broad range of temperature 60–80°C with 80°C as optimum. The Chromohalobacter sp. required 4 M NaCl for its optimum growth and protease secretion and no growth was observed below 1 M of NaCl. The initial
pH of the medium for growth and enzyme production was in the range 7.0–8.0 with optimum at pH 7.2. Various cations at 1 mM
concentration in the growth medium had no significant effect in enhancing the growth and enzyme production but 0.5 M MgCl2 concentration enhanced enzyme production. Casein or skim milk powder 1% (w/v) along with 1% peptone proved to be the best
nitrogen sources for maximum biomass and enzyme production. The carbon sources glucose and glycerol repressed the protease
secretion. Immobilization of whole cells in absence of NaCl proved to be useful for continuous production of halophilic protease. 相似文献
4.
Aims: The aim was to obtain evidences for lignin degradation by unicellular bacterium Comamonas sp. B‐9. Methods and Results: Comamonas sp. B‐9 was inoculated into kraft lignin‐mineral salt medium (KL‐MSM) at pH 7·0 and 30°C for 7 days of incubation. The bacterial growth, chemical oxygen demand (COD) reduction, secretion of ligninolytic enzymes and productions of low‐molecular‐weight compounds revealed that Comamonas sp. B‐9 was able to degrade kraft lignin (KL). COD in KL‐MSM reduced by 32% after 7 days of incubation. The maximum activities of manganese peroxidase (MnP) of 2903·2 U l?1 and laccase (Lac) of 1250 U l?1 were observed at 4th and 6th day, respectively. The low‐molecular‐weight compounds such as ethanediol, 3, 5‐dimethyl‐benzaldehyde and phenethyl alcohol were formed in the degradation of KL by Comamonas sp. B‐9 based on GC‐MS analysis. Conclusions: This study confirmed that Comamonas sp. B‐9 could utilize KL as a sole carbon source and degrade KL to low‐molecular‐weight compounds. Significance and Impact of the Study: Comamonas sp. B‐9 may be useful in the utilization and bioconversion of lignin and lignin‐derived aromatic compounds in biotechnological applications. Meanwhile, using Comamonas sp. B‐9 in treatment of wastewater in pulp and paper industry is a meaningful work. 相似文献
5.
Three pentachlorophenol (PCP) degrading bacterial strains were isolated from sediment core of pulp and paper mill effluent
discharge site. The strains were continuously enriched in mineral salts medium supplemented with PCP as sole source of carbon
and energy. One of the acclimated strains with relatively high PCP degradation capability was selected and characterized in
this study. Based on morphology, biochemical tests, 16S rDNA sequence analysis and phylogenetic characteristics, the strains
showed greatest similarity with Acinetobacter spp. The strain was identified as Acinetobacter sp. ISTPCP-3. The physiological characteristics and optimum growth conditions of the bacterial strain were investigated.
The results of optimum growth temperature revealed that it was a mesophile. The optimum growth temperature for the strain
was 30°C. The preferential initial pH for the strain was ranging at 6.5–7.5, the optimum pH was 7. The bacterium was able
to tolerate and degrade PCP up to a concentration of 200 mg/l. Increase in PCP concentration had a negative effect on biodegradation
rate and PCP concentration above 250 mg/l was inhibitory to its growth. Acinetobacter sp. ISTPCP-3 was able to utilize PCP through an oxidative route with ortho ring-cleavage with the formation of 2,3,5,6-tetrachlorohydroquinone and 2-chloro-1,4-benzenediol, identified using gas chromatograph–mass
spectrometric (GC–MS) analysis. The degradation pathway followed by isolated bacterium is different from previously characterized
pathway. 相似文献
6.
Qiu Guan Zhou Fu Bo Zhou Hong Bo Liu Xi Gao Jian Liu Fei Fei Chen Xin Hua 《World journal of microbiology & biotechnology》2007,23(9):1217-1225
A moderately thermophilic and acidophilic sulfur-oxidizing bacterium named S2, was isolated from coal heap drainage. The bacterium was motile, Gram-negative, rod-shaped, measured 0.4 to 0.6 by 1 to 2 μm,
and grew optimally at 42–45°C and an initial pH of 2.5. The strain S2 grew autotrophically by using elemental sulfur, sodium thiosulfate and potassium tetrathionate as energy sources. The strain
did not use organic matter and inorganic minerals including ferrous sulfate, pyrite and chalcopyrite as energy sources. The
morphological, biochemical, physiological characterization and analysis based on 16S rRNA gene sequence indicated that the
strain S2 is most closely related to Acidithiobacillus caldus (>99% similarity in gene sequence). The combination of the strain S2 with Leptospirillum ferriphilum or Acidithiobacillus ferrooxidans in chalcopyrite bioleaching improved the copper-leaching efficiency. Scanning electron microscope (SEM) analysis revealed
that the chalcopyrite surface in a mixed culture of Leptospirillum ferriphilum and Acidithiobacillus caldus was heavily etched. The energy dispersive X-ray (EDX) analysis indicated that Acidithiobacillus caldus has the potential role to enhance the recovery of copper from chalcopyrite by oxidizing the sulfur formed during the bioleaching
progress. 相似文献
7.
Nur Koberber Kl 《International biodeterioration & biodegradation》2009,63(6):778-781
Ochrobactrum sp., was tested with regard to its phenol degradation capacity at different pH levels, and with different carbon sources (mineral salt medium with glucose (MSG) and the same medium with 0.5%, 1%, and 2% (v/v) molasses (MSM)) and phenol concentrations. The highest degradation was in mineral salt medium with 1% (v/v) molasses (45.9%), while degradation was 21.1% in mineral salt medium with 5 g l−1 glucose. These data show that the addition of molasses to mineral salt medium enhanced phenol degradation by Ochrobactrum sp. The bacterium can be used effectively to treat wastewaters containing phenol. 相似文献
8.
9.
Kang-Hyeong Lee Rae-Hyun Koh Hong-Gyu Song 《Journal of microbiology (Seoul, Korea)》2008,46(6):641-646
A greenhouse test was carried out to examine the effects on tomato growth of application of purple non-sulfur bacterium Rhodopseudomonas sp. which had enhanced germination and growth of tomato seed under axenic conditions. The shoot length of tomato plant inoculated
by Rhodopseudomonas sp. KL9 increased by 34.6% compared to that of control in 8 weeks of cultivation. During the same period, this strain increased
120.6 and 78.6% of dry weight of shoot and root of tomato plants, respectively. The formation ratio of tomato fruit from flower
was also raised by inoculation of KL9. In addition, Rhodopseudomonas sp. KL9 treatment enhanced the fresh weight and lycopene content in the harvested tomato fruits by 98.3 and 48.3%, respectively
compared to those of the uninoculated control. When the effect on the indigenous bacterial community and fate of the inoculated
Rhodopseudomonas sp. KL9 were monitored by denaturing gradient gel electrophoresis analysis, its application did not affect the native bacterial
community in tomato rhizosphere soil, but should be repeated to maintain its population size. This bacterial capability may
be applied as an environment-friendly biofertilizer to cultivation of high quality tomato and other crops including lycopene-containing
vegetables and fruits. 相似文献
10.
A soil bacterium SW4, capable of degrading the sulfonylurea herbicide ethametsulfuron-methyl (ESM), was isolated from the
bottom soil of a herbicide factory. Based on physiological characteristics, biochemical tests and phylogenetic analysis of
the 16S rRNA gene sequence, the strain was identified as a Pseudomonas sp. The total degradation of ESM in the medium containing glucose was up to 84.6% after 6 days of inoculation with SW4 strain.
The inoculation of strain SW4 to soil treated with ESM resulted in a higher degradation rate than in noninoculated soil regardless
of the soil sterilized or nonsterilized. Five metabolites of ESM degradation were analyzed by liquid chromatography/mass spectrometry.
Based on the identified products, strain SW4 seemed to degrade ESM after two separate and different pathways: one leads to
the cleavage of the sulfonylurea bridge, whereas the other to the dealkylation and opening of the triazine ring of ESM. 相似文献
11.
S. Vishnuvardhan Reddy M. Thirumala S. K. Mahmood 《Journal of industrial microbiology & biotechnology》2009,36(6):837-843
The objective of this paper was to report a bacterium designated as 88D, capable of producing poly (3-hydroxybutyrate-co-3-hydroxyvalerate)
[P (3HB-co-3HV)] copolymer from a single carbon source, which was isolated from a municipal sewage treatment plant in Hyderabad,
India. This microorganism, based on the phenotypical features and genotypic investigations, was identified as Bacillus sp. The optimal growth of Bacillus sp. 88D occurred between 28 and 30°C and at pH 7. The strain yielded a maximum of 64.62% dry cell weight (DCW) polymer in
the medium containing glucose as carbon source, which was followed by 60.46% DCW polymer in glycerol containing medium. Bacillus sp. 88D produced P (3HB-co-3HV) from glucose or glycerol, when they were used as a single carbon substrate. This bacterium
produced polyhydrxybutyrate (PHB) when sodium acetate was used as sole carbon substrate. The viscosity average molecular mass
(Mv) of the copolymers ranged from 523 to 627 kDa. The physical, chemical and mechanical properties of the biopolymers were
characterized. 相似文献
12.
Yan Shi Liyuan Chai Chongjian Tang Zhihui Yang Huan Zhang Runhua Chen Yuehui Chen Yu Zheng 《Biotechnology for biofuels》2013,6(1):1-14
Background
Lignin materials are abundant and among the most important potential sources for biofuel production. Development of an efficient lignin degradation process has considerable potential for the production of a variety of chemicals, including bioethanol. However, lignin degradation using current methods is inefficient. Given their immense environmental adaptability and biochemical versatility, bacterial could be used as a valuable tool for the rapid degradation of lignin. Kraft lignin (KL) is a polymer by-product of the pulp and paper industry resulting from alkaline sulfide treatment of lignocellulose, and it has been widely used for lignin-related studies.Results
Beta-proteobacterium Cupriavidus basilensis B-8 isolated from erosive bamboo slips displayed substantial KL degradation capability. With initial concentrations of 0.5–6 g L-1, at least 31.3% KL could be degraded in 7 days. The maximum degradation rate was 44.4% at the initial concentration of 2 g L-1. The optimum pH and temperature for KL degradation were 7.0 and 30°C, respectively. Manganese peroxidase (MnP) and laccase (Lac) demonstrated their greatest level of activity, 1685.3 U L-1 and 815.6 U L-1, at the third and fourth days, respectively. Many small molecule intermediates were formed during the process of KL degradation, as determined using GC-MS analysis. In order to perform metabolic reconstruction of lignin degradation in this bacterium, a draft genome sequence for C. basilensis B-8 was generated. Genomic analysis focused on the catabolic potential of this bacterium against several lignin-derived compounds. These analyses together with sequence comparisons predicted the existence of three major metabolic pathways: β-ketoadipate, phenol degradation, and gentisate pathways.Conclusion
These results confirmed the capability of C. basilensis B-8 to promote KL degradation. Whole genomic sequencing and systematic analysis of the C. basilensis B-8 genome identified degradation steps and intermediates from this bacterial-mediated KL degradation method. Our findings provide a theoretical basis for research into the mechanisms of lignin degradation as well as a practical basis for biofuel production using lignin materials. 相似文献13.
Navrátilová J Tvrzová L Durnová E Spröer C Sedlácek I Neca J Nemec M 《Antonie van Leeuwenhoek》2005,87(2):149-153
The bacterial strain J3 was isolated from soil by selective enrichment on mineral medium containing 4-nitrocatechol as the sole carbon and energy source. This strain was identified as Rhodococcus wratislaviensis on the basis of morphology, biochemical, physiological and chemotaxonomic characterization and complete sequencing of the 16S rDNA gene. The isolated bacterium could utilize 4-nitrocatechol, 3-nitrophenol and 5-nitroguaiacol as sole carbon and energy sources. Stoichiometric release of nitrites was measured during degradation of 4-nitrocatechol both in growing cultures and for stationary phase cells. The J3 strain was unable to degrade 4-nitroguaiacol, 2-nitrophenol, 4-nitrophenol, 2,4-dinitrobenzoic acid, 4,5-dimethoxy-2-nitrobenzoic acid and 2,3-difluoro-6-nitrophenol. The J3 strain is deposited in the Czech Collection of Microorganisms as CCM 4930. 相似文献
14.
Neelakanteshwar K. Patil T. B. Karegoudar 《World journal of microbiology & biotechnology》2005,21(8-9):1493-1498
Summary Di-n-butylphthalate (DBP) is one of the phthalate esters (PAEs) used in the manufacture of plasticizers, insect repellents and
synthetic fibres and contributes to environmental pollution. We report a novel bacterium belonging to the genus, Bacillus (NCIM 5220), which has the ability to utilize DBP as the sole source of carbon and energy. This bacterium was immobilized
in alginate. The degradation of DBP by immobilized cells was compared with free cells. The effects on the degradation of DBP
of different factors like gel (alginate) concentration, gel bead size, temperature, and pH were investigated. Oxygen uptake
in the presence of DBP by free and immobilized cells was also studied. The results showed that the degradation of DBP by immobilized
cells was more efficient than by free cells. Further, the effect of various factors tested on the degradation of DBP by alginate-immobilized
cells showed that the degradation of DBP was remarkably affected by alginate concentration between 2 and 5% and drastically
decreased between bead size 2 and 5 mm. A change of 10 °C of reaction temperature from 30 to 40 °C did not alter the degradation
of DBP, and maximum degradation was appeared to be favoured over a broad pH range of 6.5–7.5 for immobilized cells as compared
to free cells, which showed an optimum temperature of about 35 °C and pH of 7.0. The immobilized cells showed higher oxidation
of DBP than free cells. Thus more efficient degradation of DBP could be achieved by immobilizing Bacillus sp. in alginate beads. 相似文献
15.
An aerobic microorganism with an ability to utilize phenol as carbon and energy source was isolated from a hydrocarbon contamination
site by employing selective enrichment culture technique. The isolate was identified as Arthrobacter citreus based on morphological, physiological and biochemical tests. This mesophilic organism showed optimal growth at 25°C and at
pH of 7.0. The phenol utilization studies with Arthrobacter citreus showed that the complete assimilation occurred in 24 hours. The organism metabolized phenol up to 22 mM concentrations whereas
higher levels were inhibitory. Thin layer chromatography, UV spectral and enzyme analysis were suggestive of catechol, as
a key intermediate of phenol metabolism. The enzyme activities of phenol hydroxylase and catechol 2,3-dioxygenase in cell
free extracts of Arthrobacter citreus were indicative of operation of a meta-cleavage pathway for phenol degradation. The organism had additional ability to degrade catechol, cresols and naphthol. The
degradation rates of phenol by alginate and agar immobilized cells in batch fermentations showed continuous phenol metabolism
for a period of eight days. 相似文献
16.
Curvularia lunata var.aeria was grown in YPD (yeast extract, peptone, and dextrose) medium (pH 6.5) at 28°C with varying concentrations (10–40 g/L) of glucose for the production of rifamycin oxidase. Enzyme activity and glucose concentration were found to be indirectly related to the production of black intracellular pigment by the organism. Depletion of glucose level and rise of culture pH initiate the synthesis of pigment. Carboxymethylcellulose (CMC) was used as a carbon source to improve the enzyme yield, but utilization of the substrate in the reactor was much less. Compared with 10 g/L of CMC in the medium, low or high concentrations of CMC did not yield any better result. Addition of glucose in YPC (yeast extract, peptone, and CMC) medium did not increase the enzyme activity, and glucose was rapidly utilized byC. lunata, forming pellets rather than mycelia. 相似文献
17.
Gluconacetobacter diazotrophicus was grown in chemostat under N2-fixing conditions at different culture pH values (from 2.5 to 7.5) with glucose as the C-source. Maximum glucose and oxygen
utilization yields were observed at pH values between 5.0 and 6.5. Yields, although lower, were not severely affected at acidic
(2.5–4.5) and moderate alkaline (7.5) pH values. But, at pH values just over 7.5, cultures became unstable and washed out.
Maximum biomass yields coincided with optimal activity (and minimal synthesis) of pyrroloquinoline quinone (PQQ)-linked glucose
dehydrogenase (PQQ-GDH). At external pH values of 7.0 and above, whereas PQQ-GDH was actively synthesized, a very low in situ
activity could be detected. The lack of PQQ-GDH activity at moderate alkaline pH values seems to be the cause of lack of growth
of this organism under these conditions. 相似文献
18.
Kim HS Golyshin PN Timmis KN 《Journal of industrial microbiology & biotechnology》2007,34(11):715-721
A metalloprotease induced by chitin in a new chitinolytic bacterium Serratia sp. Strain KCK was purified and characterized. Compared with other Serratia enzymes, it exhibited a rather broad pH activity
range (pH 5.0–8.0), and thermostability. The cognate ORF, mpr, was cloned and expressed. Its deduced amino acid sequence showed high similarity to those of bacterial zinc-binding metalloproteases
and a well-conserved serralysin family motif. Pretreatment of chitin with the Mpr protein promoted chitin degradation by chitinase
A, which suggests that Mpr participates in, and facilitates, chitin degradation by this microorganism. 相似文献
19.
Li-Jian Xu Yuan-Shuai Liu Li-Gang Zhou Jian-Yong Wu 《Biotechnology and Bioprocess Engineering》2010,15(3):460-466
Beauvericin (BEA) is a proven and potent antibiotic compound useful for bio-control and a potential antifungal and anticancer
agent for human. This study was to evaluate and optimize the nutrient medium for BEA production in mycelial liquid culture
of a high BEA-producing fungus Fusarium redolens Dzf2 isolated from a medicinal plant. Among various organic and inorganic carbon and nitrogen sources, glucose and peptone
were found the most favorable for the F. redolens Dzf2 mycelial growth and BEA production. Through a Plackett-Burman screening test on a basal medium, glucose, peptone, and
medium pH were identified as the significant factors for mycelial growth and BEA production. These factors were optimized
through central composite design of experiments and response surface methodology, as 49.0 g/L glucose, 13.0 g/L peptone and
pH 6.6, yielding 198 mg/L BEA (versus 156 mg/L in the basal medium). The BEA yield was further increased to 234 mg/L by feeding
10 g/L glucose to the culture during exponential phase. The results show that F. redolens Dzf2 mycelial fermentation is a feasible and promising process for production of BEA. 相似文献
20.
P. S. Apte M. V. Deshpande V. Shankar 《World journal of microbiology & biotechnology》1993,9(2):205-209
A strain of Rhizopus stolonifer produced a high activity of extracellular DNAase when grown on YPG (yeast extract peptone glucose) medium. The source of peptone had a marked effect on the enzyme yield and only one peptone (i.e. from Sarabhai M. Chemicals Ltd, India) supported enzyme production. Maximum enzyme activity (88 U/ml) was obtained after 4 days' growth under submerged conditions in YPG medium containing 100 M Mn2+, Co2+ or Mg2+, and glucose as the sole carbon source. The unpurified enzyme was optimally active at pH 7.5 and 45°C. It had a higher activity with sonicated and heat-denatured DNA than native DNA. 相似文献