scholarly journals An Extremely Oligotrophic Bacterium, Rhodococcus erythropolis N9T-4, Isolated from Crude Oil

2007 ◽  
Vol 189 (19) ◽  
pp. 6824-6831 ◽  
Author(s):  
Naoko Ohhata ◽  
Nobuyuki Yoshida ◽  
Hiroshi Egami ◽  
Tohoru Katsuragi ◽  
Yoshiki Tani ◽  
...  
Keyword(s):  
Crude Oil ◽  
Aldehyde Dehydrogenase ◽  
Rhodococcus Erythropolis ◽  
Cell Extract ◽  
Minimal Salt Medium ◽  
Methylotrophic Bacteria ◽  
Salt Medium ◽  
Molecular Masses ◽  
Ribulose Monophosphate Pathway ◽  
Formaldehyde Metabolism

ABSTRACT Rhodococcus erythropolis N9T-4, which was isolated from crude oil, showed extremely oligotrophic growth and formed its colonies on a minimal salt medium solidified using agar or silica gel without any additional carbon source. N9T-4 did not grow under CO2-limiting conditions but could grow on a medium containing NaHCO3 under the same conditions, suggesting that the oligotrophic growth of N9T-4 depends on CO2. Proteomic analysis of N9T-4 revealed that two proteins, with molecular masses of 45 and 55 kDa, were highly induced under the oligotrophic conditions. The primary structures of these proteins exhibited striking similarities to those of methanol: N,N′-dimethyl-4-nitrosoaniline oxidoreductase and an aldehyde dehydrogenase from Rhodococcus sp. These enzyme activities were three times higher under oligotrophic conditions than under n-tetradecane-containing heterotrophic conditions, and gene disruption for the aldehyde dehydrogenase caused a lack of growth on the minimal salt medium. Furthermore, 3-hexulose 6-phosphate synthase and phospho-3-hexuloisomerase activities, which are key enzymes in the ribulose monophosphate pathway in methylotrophic bacteria, were detected specifically in the cell extract of oligotrophically grown N9T-4. These results suggest that CO2 fixation involves methanol (formaldehyde) metabolism in the oligotrophic growth of R. erythropolis N9T-4.

scholarly journals CRUDE OIL BIOREMEDIATION BY INDIGENOUS BACTERIA ISOLATED FROM OILY SLUDGE

2016 ◽  
Vol 78 (11-2) ◽  
Author(s):  
Nur Hafizah Azizan ◽  
Kasing Ak Apun ◽  
Lesley Maurice Bilung ◽  
Micky Vincent ◽  
Hairul Azman Roslan ◽  
...  
Keyword(s):  
Crude Oil ◽  
Enrichment Culture ◽  
Molecular Techniques ◽  
Oily Sludge ◽  
Minimal Salt Medium ◽  
Alkane Degradation ◽  
Growth Study ◽  
The Third ◽  
Cell Counts ◽  
Degrading Bacteria

Enrichment culture technique leads to the discovery of six presumptive TPH-degrading bacteria. Identification and characterization tests using morphological, biochemical and molecular techniques have successfully isolated Pseudomonas aeruginosa (UMAS1PF), Serratia marcescens (UMAS2SF) and Klebsiella spp. (UMAS3KF). All strains were able to use crude oil as sole carbon and energy source for their growth since they were able to survive in Minimal Salt medium supplemented with 1% (v/v) crude oil. Growth study showed that they produced the highest cell counts on the third or fourth day by 108 – 1011 CFU/ml. Six artificial consortium inoculums have been produced from the growth study. Gas chromatography analysis showed that all isolates had the ability to degrade aliphatic hydrocarbon with 100% degradation of nC19 – C24. Among the isolates, UMAS2SF was the best and fastest n-alkane degrader with degradation percentage between 55 – 90% of n-C14 – C18 in 14 days. This was followed by UMAS1PF and UMAS3KF with 11 – 82% and 1.3% degradation, respectively. Enhancement study showed that plot with inoculum and NPK addition successfully enhanced n-alkane degradation. Plot A2:B3+NPK degraded n-alkane the fastest followed by plot treated by C+NPK, A1:B2, B+NPK and A2:B3. Result showed that UMAS1PF was the best PAHs degrader as most of the high molecular weight PAHs was degraded. In the enhancement study, the plot amended with A2:B3 showed the highest PAHs degradation, followed by plots A1:B2, A3:B1:C2 and A1:C3 that was assigned as the third, fourth and fifth best in mineralizing PAHs, respectively.

scholarly journals Wild type Bacillus subtilis treated with ethyl methyl sulphonate produced catabolite insensitive mutants with improved cellulase production

2021 ◽  
Author(s):  
Oladipo Olaniyi
Keyword(s):  
Bacillus Subtilis ◽  
Carbon Source ◽  
Enzyme Production ◽  
Cellulase Activity ◽  
Cellulase Production ◽  
Minimal Salt Medium ◽  
Salt Medium ◽  
Production Medium ◽  
Wild Type ◽  
Ethyl Methyl

Abstract The goal of this present investigation was to mutagenize Bacillus subtilis with Ethyl Methyl Sulphonate (EMS), screen the mutants for cellulase production and evaluate the influence of different glucose concentrations on their cellulase production potentials. The wild type B. subtilis was treated with 20, 40, 60 and 80 µl of EMS and the mutants generated were screened for cellulase production in minimal salt medium containing carboxylmethylcellulose (CMC) as the carbon source. Quantitatively, cellulase activity and protein contents were determined by dinitrosalicylic acid and Lowry methods respectively. Seven mutants were developed from each of the EMS concentration bringing the total to twenty-eight from all the concentrations. Approximately 14 and 57% of the mutants developed from 40 and 60µl of EMS had higher cellulase activities than the wild type, while none of the mutants developed from 20 and 80 µl of EMS had better activities than the wild type. The supplementation of 0.2, 0.5, 1.0 and 1.5% glucose in enzyme production medium caused approximately 100, 14, 29 and 14% cellulase repression respectively in the mutants developed from 60µl EMS. Mutants MSSS02 and MSSS05 were considered as catabolite insensitive mutants because their cellulase production were enhanced in comparison to wild type.

scholarly journals Evidence for Enhanced Dissipation of Chlorpyrifos in an Agricultural Soil Inoculated with Serratia Rubidaea Strain ABS 10

2021 ◽  
Author(s):  
Asma Ben Salem ◽  
Hanene Chaabane ◽  
Tesnime Ghazouani ◽  
Pierluigi Caboni ◽  
Valentina Coroneo ◽  
...  
Keyword(s):  
16S Rrna ◽  
Bacterial Strain ◽  
Agricultural Soil ◽  
Liquid Culture ◽  
Minimal Salt Medium ◽  
Salt Medium ◽  
Sterile Soil ◽  
Rrna Sequencing ◽  
Biochemical Analyses ◽  
Serratia Rubidaea

Abstract Important mineralization of 14C-chlorpyrifos was found in a Tunisian soil exposed repeatedly to this insecticide. A bacterial strain able to grow in minimal salt medium (MSM) supplemented with 25 mg L− 1 of chlorpyrifos was isolated from this soil. It was characterized as Serratia rubidaea strain ABS 10 using morphological and biochemical analyses, as well as 16S rRNA sequencing. In liquid culture S. rubidaea stain ABS 10 was able to almost entirely dissipate chlorpyrifos within 48 hours of incubation. Although, S. rubidaea strain ABS 10 was able to grow on MSM supplemented with chlorpyrifos and to dissipate it in liquid culture, it was not able to mineralize 14C-chlorpyrifos. Therefore, one can conclude that the dissipation capability of this bacteria might be attributed to its capacity to adsorb CHL. In both non-sterile and sterile soil inoculated with S. rubidaea strain ABS 10, chlorpyrifos was more rapidly dissipated than in respective controls.

Effects of Heat, Acid, and Freeze-Thaw Challenges on Survival of Starved Vibrio parahaemolyticus in Minimal Salt Medium, Tryptic Soy Broth, and Filtered Oyster Homogenate Medium

2004 ◽  
Vol 67 (6) ◽  
pp. 1243-1246 ◽  
Author(s):  
H.-C. WONG ◽  
C.-N. CHANG ◽  
M.-Y. CHEN
Keyword(s):  
Stress Resistance ◽  
Vibrio Parahaemolyticus ◽  
Minimal Salt Medium ◽  
Bacterial Cells ◽  
Salt Medium ◽  
Gram Negative ◽  
Freeze Thaw ◽  
Low Salinity ◽  
Medium Resistance

Vibrio parahaemolyticus is a ubiquitous gram-negative enteropathogenic bacterium. To evaluate the risk of stress-adapted V. parahaemolyticus cells in food, we investigated the survivability of starvation-adapted and starvation-low salinity–adapted cells of this pathogen in different media against different stresses. Logarithmically grown bacterial cells were starved at 25°C in a minimal salt medium with 0.5 or 3.0% NaCl for 24 h. Resistances against challenges of heat, acid, and freeze-thaw treatment exhibited by the starvation-adapted cells were similar to those exhibited by the starvation-low salinity–adapted cells but substantially higher than those of the unadapted control cells. The increased stress resistance of the adapted cells against freeze-thaw challenge was lower in tryptic soy broth than in the starving medium. Resistance of the adapted bacteria against heat and freeze-thaw treatment was completely eliminated in filter-sterilized oyster homogenate medium. Practically, these results help to assess the risk of stress-adapted V. parahaemolyticus in food.

scholarly journals Characterization of an Exceedingly Active NADH Oxidase from the Anaerobic Hyperthermophilic Bacterium Thermotoga maritima

2007 ◽  
Vol 189 (8) ◽  
pp. 3312-3317 ◽  
Author(s):  
Xianqin Yang ◽  
Kesen Ma
Keyword(s):  
Nadh Oxidase ◽  
Specific Activity ◽  
Ph Value ◽  
Thermotoga Maritima ◽  
Cell Extract ◽  
Hyperthermophilic Bacterium ◽  
Its Gene ◽  
Molecular Masses ◽  
New Type

ABSTRACT An NADH oxidase from the anaerobic hyperthermophilic bacterium Thermotoga maritima was purified. The enzyme was very active in catalyzing the reduction of oxygen to hydrogen peroxide with an optimal pH value of 7 at 80°C. The Vmax was 230 ± 14 μmol/min/mg (k cat/Km = 548,000 min−1 mM−1), and the Km values for NADH and oxygen were 42 ± 3 and 43 ± 4 μM, respectively. The NADH oxidase was a heterodimeric flavoprotein with two subunits with molecular masses of 54 kDa and 46 kDa. Its gene sequences were identified, and the enzyme might represent a new type of NADH oxidase in anaerobes. An NADH-dependent peroxidase with a specific activity of 0.1 U/mg was also present in the cell extract of T. maritima.

scholarly journals Biosurfactant production by Trichoderma sp. MK116452 and its possible application in oil recovery

2020 ◽  
Author(s):  
Nur Bazilah Afifah Matussin ◽  
Pooja Shivanand ◽  
Lee Hoon Lim
Keyword(s):  
Crude Oil ◽  
Oil Recovery ◽  
Artemia Salina ◽  
Culture Broth ◽  
Minimal Salt Medium ◽  
Filling Station ◽  
Brunei Darussalam ◽  
Trichoderma Sp ◽  
A Cell ◽  
Red Bean

Abstract Surfactants are amphiphatic compounds containing both hydrophilic and hydrophobic groups, which are capable of lowering surface or interfacial tension. Considering the advantages of using biosurfactants produced by microorganisms, the aim of this study was to develop and characterise a biosurfactant produced by Trichoderma sp. MK116452 isolated from Seri Cermin filling station, Brunei Darussalam, and to examine its potential application in microbial enhanced oil recovery (MEOR). The microorganism was cultured in a minimal salt medium containing 1% crude oil as a carbon source and a cell-free culture broth was used to screen its efficiency in producing biosurfactants. Characterisation of the biosurfactant showed the presence of glycosides and fatty acids, suggesting its glycolipidic nature. The isolated biosurfactant showed no toxicity to the micro-crustacean Artemia salina or to red bean ( Vigna angularis ). The extracted biosurfactant was effective at recovering up to 60% of crude oil from sand using the sand pack column method, which is similar to the recovery rate for a chemical surfactant (SDS) (65%). These findings highlight the potential use of Trichoderma sp. MK116452 biosurfactant in the oil industry.

scholarly journals Molecular identification of insecticide degradation by gut bacteria isolated from Helicoverpa armigera of Cotton plants

2021 ◽  
Vol 13 (2) ◽  
pp. 641-653
Author(s):  
Madhusudhan S ◽  
S.K. Jalali ◽  
Sibi G
Keyword(s):  
Insecticide Resistance ◽  
Helicoverpa Armigera ◽  
Gut Bacteria ◽  
Rrna Gene ◽  
Minimal Salt Medium ◽  
Salt Medium ◽  
Bacterial Isolates ◽  
Insecticide Degradation ◽  
Helicoverpa Armígera ◽  
Rhodococcus Sp

The cotton bollworm Helicoverpa armigera occurs as a major pest in many economically important crops, including cotton, pigeon pea, chickpea, pea, cowpea, sunflower, tomato, sorghum, pearl millet and other crops. Intestinal microorganisms play important role in the degradation of diet components of insects. In order to know the role of gut bacteria in insecticide resistance five   insecticides Chlorpyriphos (20% EC), Cypermethrin (25% EC), Malathion (50% EC), Quinalphos (25% EC), Triazophos (40% EC), were selected for the insecticide degradation studies. All the bacterial isolates from the gut of lab and field populations of H. armigera were identified using 16S rRNA gene-based identification and tested for their growth on minimal salt medium (MSM) along with the selected insecticides. A total of 11 bacterial isolates were tested and among them, isolate CL4 (Rhodococcus sp.) was found to grow on minimal salt medium (MSM) and with chlorpyriphos and isolate CL2 (Enterococcus casseliflavus) was able to grow in MSM with chloropyriphos (C22H19Cl2NO3) and malathion (C10H19O6PS2) and no growth was seen in MSM without insecticide (control).  Gas Chromatography analysis of the positive bacterial isolate cultures in MSM showed that the isolate CL4 (Rhodococcus sp.) was able to utilize 43.9% of chlorpyriphos and isolate CL2 (E.casseliflavus) was able to utilize 26% of chlorpyriphos and 57.1% of malathion in MSM broth cultures with comparison with the respective control cultures. Findings of the current work suggested that gut bacteria in the field populations of H. armigera plays a role in insecticide resistance

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