Bioleaching of Aluminum Slags with Thermophilic Bacteria

2015 ◽  
Vol 1130 ◽  
pp. 414-417
Author(s):  
R.E. Rivera Santillan ◽  
F. Patricio Ramirez ◽  
V.D. Aguilar Perez
Keyword(s):  
Redox Potential ◽  
Bacterial Growth ◽  
Nutrient Medium ◽  
Industrial Waste ◽  
Thermophilic Bacteria ◽  
Metallic Aluminum ◽  
Secondary Aluminum ◽  
Thermophilic Microorganisms ◽  
Lack Of Information ◽  
Smelting Slag

The recovery of metallic aluminum from the waste generated in the production of secondary aluminum by bioleaching process using the nutrient medium MKM was investigated. The development of this project was carried out due to the need to treat waste foundry which have a major impact on the environment, using environmentally friendly techniques, such as bioleaching. At work, bioleaching of smelting slag of aluminum generated in the laboratories of the Department of Metallurgy, Faculty of Chemistry, UNAM, was reported. Tests were conducted using thermophilic microorganisms at 70°C in an orbital incubator at natural pH, obtaining metallic clean aluminum, aluminum in solution and salts solution. The pH, bacterial growth and redox potential were monitored daily. We conclude that bioleaching of aluminum slags is feasible. The lack of information about the treatment of this type of industrial waste, makes this research is pioneer in this field.

scholarly journals Cadmium Ion Biosorption by the Thermophilic Bacteria Geobacillus stearothermophilus and G. thermocatenulatus

2006 ◽  
Vol 72 (6) ◽  
pp. 4020-4027 ◽  
Author(s):  
Adrian Hetzer ◽  
Christopher J. Daughney ◽  
Hugh W. Morgan
Keyword(s):  
Metal Ion ◽  
Functional Group ◽  
Thermophilic Bacteria ◽  
Toxicity Tests ◽  
Ion Adsorption ◽  
Geobacillus Stearothermophilus ◽  
Cadmium Ion ◽  
Thermophilic Microorganisms ◽  
Gram Positive Bacteria ◽  
Metal Ion Adsorption

ABSTRACT This study reports surface complexation models (SCMs) for quantifying metal ion adsorption by thermophilic microorganisms. In initial cadmium ion toxicity tests, members of the genus Geobacillus displayed the highest tolerance to CdCl2 (as high as 400 to 3,200 μM). The thermophilic, gram-positive bacteria Geobacillus stearothermophilus and G. thermocatenulatus were selected for further electrophoretic mobility, potentiometric titration, and Cd2+ adsorption experiments to characterize Cd2+ complexation by functional groups within and on the cell wall. Distinct one-site SCMs described the extent of cadmium ion adsorption by both studied Geobacillus sp. strains over a range of pH values and metal/bacteria concentration ratios. The results indicate that a functional group with a deprotonation constant pK value of approximately 3.8 accounts for 66% and 80% of all titratable sites for G. thermocatenulatus and G. stearothermophilus, respectively, and is dominant in Cd2+ adsorption reactions. The results suggest a different type of functional group may be involved in cadmium biosorption for both thermophilic strains investigated here, compared to previous reports for mesophilic bacteria.

Protein Metabolism in Trematode Parasites

1958 ◽  
Vol 32 (3) ◽  
pp. 119-124 ◽  
Author(s):  
M. M. Goil
Keyword(s):  
Uric Acid ◽  
Bacterial Growth ◽  
Protein Metabolism ◽  
Nutrient Medium ◽  
Dry Weight ◽  
Fasciola Gigantica ◽  
Starvation Period ◽  
Gastrothylax Crumenifer ◽  
Suitable Temperature ◽  
Trematode Parasites

Paramphistomum explanation, Gastrothylax crumenifer, and Fasciola gigantica were maintained for periods of twelve hours in a non-nutrient medium containing streptomycin and penicillin to prevent bacterial growth. They were kept under aerobic conditions at a suitable temperature of 37%C. The protein content in P. explanatum ranged from 50·0% to 54·7% with an average of 52·96%±0·23 of the dry weight of the tissue. In G. crumenifer it ranged from 43·5% to 51·5% with an average of 48·8%±0·56 of d.w.t. In F. gigantica it ranged from 63·8% to 68·3% with an average of 66·5%±0·26 of d.w.t. The nitrogen content of the P. explanation excreted as ammonia after a starvation period of twelve hours was 3·95% and as uric acid it was 0·077%. In G. crumenifer the ammonia was 2·91% and uric acid 0·033%. In F. gigantica ammonia was 2·51% and uric acid 0·1%.

Molybdenite Bioleaching by Thermophilic Bacteria in a RELVA-ARBP Bioreactor

2013 ◽  
Vol 825 ◽  
pp. 418-422
Author(s):  
Rosa Elva Rivera-Santillán ◽  
Felipe Patricio-Ramírez ◽  
Francisco Artuto López-López
Keyword(s):  
Necessary Conditions ◽  
Thermophilic Bacteria ◽  
Optimal Growth ◽  
Bacterial Strains ◽  
Chemical Parameters ◽  
Thermophilic Microorganisms ◽  
Solubility In Water ◽  
Physical Chemical ◽  
Difficult Condition ◽  
Nutrients Concentration

The biological technologies application in sulfide minerals leaching to the recovery of valuables metal is a very important technological advance. They are environmental friendly and favor the sustainability of metals production in the mining and metals industry. Nowadays there is not enough basic information on molybdenite bioleaching, as well as there isn`t equip capable to obtain efficient molybdenum extractions. The difficulty depends in part on microorganisms tolerance to the molybdenum. An 85% molybdenum extraction in 6 months has been reported. This work assesses the molybdenite bioleaching from a concentrate (MoS2) with thermophilic microorganisms, at a temperature of 65 °C, on a new reactor designed at the Faculty of Chemistry of the Universidad Nacional Autónoma de México, to obtain higher extractions of molybdenum. Since bioleaching an aerobic process, the oxygen transference is a difficult condition to achieve because its solubility in water is very low and in the air 20.9 %. In addition to homogenize and maintain constant the nutrients concentration, in this new bioreactor could be established the physical, chemical and biological conditions that lead to the microorganisms optimal growth, due to these are environmental sensitive. This new equip allows us mix the nutrients in a homogeneous way. Also is able maintain constant the nutrients concentration, and all controlled physical, biological and chemical parameters. Finally does not cause any microorganisms damage. The RELVA-ARBP bioreactor allows us the control of necessary conditions for a growth more efficient of the bacterial strains. This will allow leach more rapidly the ore, increasing the molybdenum extraction kinetics. The tests results of bioleaching molybdenite with a mixed strain of extreme thermophiles carried out at 65 °C in an orbital incubator and in the RELVA-ARBP bioreactor, show a better efficiency of the bioreactor used.

scholarly journals Steroid Metabolism in Thermophilic Actinobacterium Saccharopolyspora hirsuta VKM Ac-666T

2021 ◽  
Vol 9 (12) ◽  
pp. 2554
Author(s):  
Tatyana Lobastova ◽  
Victoria Fokina ◽  
Sergey Tarlachkov ◽  
Andrey Shutov ◽  
Eugeny Bragin ◽  
...  
Keyword(s):  
Thermophilic Bacteria ◽  
Cholesterol Oxidase ◽  
Cascade Reactions ◽  
Cholesterol Oxidation ◽  
P450 Monooxygenase ◽  
Thermophilic Microorganisms ◽  
Mycobacterium Tuberculosis H37rv ◽  
Rhodococcus Jostii Rha1 ◽  
Saccharopolyspora Hirsuta ◽  
Steroid Catabolism

The application of thermophilic microorganisms opens new prospects in steroid biotechnology, but little is known to date on steroid catabolism by thermophilic strains. The thermophilic strain Saccharopolyspora hirsuta VKM Ac-666T has been shown to convert various steroids and to fully degrade cholesterol. Cholest-4-en-3-one, cholesta-1,4-dien-3-one, 26-hydroxycholest-4-en-3-one, 3-oxo-cholest-4-en-26-oic acid, 3-oxo-cholesta-1,4-dien-26-oic acid, 26-hydroxycholesterol, 3β-hydroxy-cholest-5-en-26-oic acid were identified as intermediates in cholesterol oxidation. The structures were confirmed by 1H and 13C-NMR analyses. Aliphatic side chain hydroxylation at C26 and the A-ring modification at C3, which are putatively catalyzed by cytochrome P450 monooxygenase CYP125 and cholesterol oxidase, respectively, occur simultaneously in the strain and are followed by cascade reactions of aliphatic sidechain degradation and steroid core destruction via the known 9(10)-seco-pathway. The genes putatively related to the sterol and bile acid degradation pathways form three major clusters in the S. hirsuta genome. The sets of the genes include the orthologs of those involved in steroid catabolism in Mycobacterium tuberculosis H37Rv and Rhodococcus jostii RHA1 and related actinobacteria. Bioinformatics analysis of 52 publicly available genomes of thermophilic bacteria revealed only seven candidate strains that possess the key genes related to the 9(10)-seco pathway of steroid degradation, thus demonstrating that the ability to degrade steroids is not widespread among thermophilic bacteria.

scholarly journals ISOLATION OF THERMOPHILIC LIPASE PRODUCING BACTERIUM FROM HOT SPRINGS AT THE EAST COAST OF PENINSULAR MALAYSIA

2021 ◽  
Vol 11 (1) ◽  
pp. 1-10
Author(s):  
Tengku Hamid ◽  
◽  
Nur Abidin ◽  
Nurmusfirah Hasan ◽  
◽  
...  
Keyword(s):  
Hot Springs ◽  
East Coast ◽  
Hot Spring ◽  
Thermophilic Bacteria ◽  
Natural Habitat ◽  
Primary Source ◽  
Industrial Applications ◽  
Peninsular Malaysia ◽  
Thermostable Enzymes ◽  
Thermophilic Microorganisms

Hot spring is a natural habitat for thermophilic bacteria and the primary source of thermostable enzymes useful in industrial applications. In Malaysia, the search for thermophilic organisms has been focused on hot springs, especially on the peninsular West coast. In this work, lipase or esterase producing thermophilic microorganisms were isolated from East coast hot springs in Pahang and Terengganu's states. Morphological and biochemical analysis were carried out on Isolates LH1, LH2, LH3, LH4, LH5, B2B2 and S1B4, which showed that they are gram positive, aerobic, spore forming, and motile organisms. All of the seven isolates showed the ability to grow at 45°C and formed hydrolysis zones on tributyrin agar plates. However, only isolate B2B2 and S1B4 were able to thrive at higher temperatures of up to 65°C. The genotypic characterisation was carried out using 16S rRNA sequencing. Bacillus and Geobacillus species were found to be the dominant bacteria isolated from these hot springs. From La hot spring, isolate LH1 (MT 645486), Isolates LH2 (MT645483), LH3 (MT645484), LH4 (MT 645485) and LH5 (MT 645487) were all closely related to Bacillus sp. (at 97.3-97.9%). Meanwhile, from Bentong and Sungai Lembing hot springs, isolates B2B2 (MT668631) and S1B4 (MT668632) were near related to either Geobacillus kaustophilus or Geobacillus thermoleovorans; each at 98.5% and 97.9% similarity, respectively. These strains from Geobacillus sp. were able to thrive at higher temperature and their thermostable esterases or lipases have properties useful for biotechnological applications.

Effect of redox potential on bioleaching of chalcopyrite by moderately thermophilic bacteria: An emphasis on solution compositions

2015 ◽  
Vol 151 ◽  
pp. 141-150 ◽  
Author(s):  
Hongbo Zhao ◽  
Jun Wang ◽  
Congren Yang ◽  
Minghao Hu ◽  
Xiaowen Gan ◽  
...  
Keyword(s):  
Redox Potential ◽  
Thermophilic Bacteria ◽  
Moderately Thermophilic

scholarly journals Isolation, characterization and molecular identification of protease producing bacteria from Tashkooh mountain located in Ahvaz, Iran

2015 ◽  
Vol 9 (2) ◽  
pp. 39-42 ◽  
Author(s):  
Arezoo Ebrahimpour ◽  
Ashraf Kariminik
Keyword(s):  
Proteolytic Activity ◽  
Thermophilic Bacteria ◽  
Skim Milk ◽  
Subtilis Strain ◽  
Industrial Enzymes ◽  
Thermophilic Microorganisms ◽  
Rrna Sequencing ◽  
Extracellular Protease Activity ◽  
Phenotypic Tests ◽  
G 13

Thermophilic microorganisms have gained worldwide importance due to their remarkable potential to produce thermostable and thermoactive enzymes that have wide applications in pharmaceuticals and industries. Therefore, the isolation of thermophilic bacteria from natural sources and their identification are very important in terms of discovering new industrial enzymes. The aim of this research was therefore the isolation of protease producing thermophilic bacteria from Tashkooh or firing mount located in Ahvaz, Iran. 8 bacterial isolates were screened. These strains were examined for the existence of extracellular protease activity. All 8 isolated bacteria showed proteolytic activity on nutrient agar with skim-milk. 3 bacteria showed their optimum growth at alkaline pH and grew maximally at different temperature in the thermophilic range and had proteolytic activity at pH 11 in 70?C and pH 9 in 55?C.The best carbon source for proteolytic activity was starch. After performing some phenotypic tests determined that all the isolates were Gram positive, endospore forming rods, aerobic, capable to produce catalase, amylase and gelatinase enzymes and they were identified as Bacillus sp. The best isolated bacteria was identified molecularly with the aid of 16S rRNA sequencing and data revealed that the Bacillus subtilis strain G-13 (GenBank accession No. KJ139434.1).The investigation confirmed that the isolate to be a true thermophile and could be a source of thermostable protease which can be exploited for pharmaceutical and industrials applications.DOI: http://dx.doi.org/10.3126/ijls.v9i2.12054 International Journal of Life Sciences 9 (2) : 2015; 39-42

Prevention of bacterial growth in a long-distance water supply system: control of disinfection capacity

2003 ◽  
Vol 3 (1-2) ◽  
pp. 223-225
Author(s):  
R. Fischeder ◽  
W. Weber
Keyword(s):  
Drinking Water ◽  
Surface Water ◽  
Redox Potential ◽  
Bacterial Growth ◽  
Chlorine Dioxide ◽  
System Control ◽  
Water Production ◽  
Long Distance ◽  
Growth Measurement ◽  
Drinking Water Production

Drinking water has to be wholesome and clean, free from chemical and, most of all, microbiological contaminants. The German Landeswasserversorgung (LW), a long distance water supplier, uses surface water and water influenced by surface water as well as groundwater for drinking water production. A combination of several treatment steps including flocculation, sedimentation, ozonation, in-line filtration and, finally, disinfection with chlorine dioxide guarantees a drinking water of perfect quality. Since the water transport through several main and subsidiary pipes of an overall length of about 500 kilometres can take up to four days, the disinfection capacity must be sufficient to prevent bacterial growth. Measurement of the redox potential in addition to measurement of chlorine dioxide concentrations has proved to be a helpful parameter for the surveillance of the disinfection capacity. Many years of experience show that keeping the redox potential above a level of 650 mV guarantees the prevention of bacterial growth and an efficient disinfection.

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