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 Steroid Metabolism In Thermophilic Actinobacteria Saccharopolyspora Hirsuta Subsp. Hirsuta VKM Ac-666T

2021 ◽  
Author(s):  
Tatyana Gennadyevna Lobastova ◽  
Victoria V. Fokina ◽  
Sergey V. Tarlachkov ◽  
Andrey A. Shutov ◽  
Eugeny Yu. Bragin ◽  
...  
Keyword(s):  
Structural Modification ◽  
Thermophilic Bacteria ◽  
Cholesterol Oxidase ◽  
Bioinformatic Analysis ◽  
Degradation Pathway ◽  
Side Chain ◽  
P450 Monooxygenase ◽  
Key Genes ◽  
Saccharopolyspora Hirsuta ◽  
Steroid Catabolism

Abstract Application of thermophile microorganisms opens new prospects in steroid biotechnology, however little is known on steroid catabolism by the thermophile strains.The thermophilic Saccharopolyspora hirsuta subsp. hirsuta strain VKM Ac-666T is capable of structural modification of different steroids, and fully degrades cholesterol. The intermediates of the cholesterol degradation pathway were identified as 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 by MS, and H1- and C13-NMR analyses. The data evidence sterol degradation by the strain occurs simultaneously through the aliphatic side chain hydroxylation at C26 and the A-ring modification that are putatively catalyzed by cytochrome P450 monooxygenase CYP125 and cholesterol oxidase, respectively.The genes orthologous to those related to the sterol side chain degradation, steroid core rings A/B and C/D disruption and the steroid uptake were revealed. Most of the genes related to steroid degradation are grouped in three clusters. The sets of the genes putatively involved in steroid catabolism and peculiarities of their organization in S. hirsuta are discussed.Despite steroids abundancy in the environments, the ability to degrade them is not widespread among thermophilic bacteria as follows from the bioinformatic analysis of 52 publicly available genomes. Only seven candidate strains were revealed to possess the key genes related to the only known 9(10)-seco pathway of steroid degradation.The results contribute to the knowledge on diversity of microbial steroid degraders, the features of sterol catabolism by thermophilic actinobacteria and could be useful for application in the pharmaceutical and environmental biotechnology.

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.

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 7-Ketocholesterol Catabolism by Rhodococcus jostii RHA1

2009 ◽  
Vol 76 (1) ◽  
pp. 352-355 ◽  
Author(s):  
Jacques M. Mathieu ◽  
William W. Mohn ◽  
Lindsay D. Eltis ◽  
Justin C. LeBlanc ◽  
Gord R. Stewart ◽  
...  
Keyword(s):  
Differentially Expressed Genes ◽  
Gene Clusters ◽  
Differentially Expressed ◽  
Large Gene ◽  
Key Genes ◽  
Rhodococcus Jostii Rha1 ◽  
Harmful Effects ◽  
Steroid Catabolism ◽  
Rhodococcus Jostii

ABSTRACT Oxysterols from steroid autooxidation have numerous harmful effects, but their biodegradation is poorly understood. Microarrays were used to study mineralization of the most common oxysterol, 7-ketocholesterol (7KC), by Rhodococcus jostii RHA1. Growth on 7KC versus growth on cholesterol resulted in 363 differentially expressed genes, including upregulation of two large gene clusters putatively encoding steroid catabolism. Despite this difference, 7KC degradation required key genes involved in cholesterol degradation, indicating a common catabolic route.

scholarly journals Reductive Power Generated by Mycobacterium leprae Through Cholesterol Oxidation Contributes to Lipid and ATP Synthesis

2021 ◽  
Vol 11 ◽  
Author(s):  
Thabatta L. S. A. Rosa ◽  
Maria Angela M. Marques ◽  
Zachary DeBoard ◽  
Kelly Hutchins ◽  
Carlos Adriano A. Silva ◽  
...  
Keyword(s):  
Ldl Cholesterol ◽  
Cholesterol Oxidase ◽  
Close Association ◽  
Atp Synthesis ◽  
Mycobacterium Leprae ◽  
Cholesterol Oxidation ◽  
Bacterial Survival ◽  
Catabolic Pathway ◽  
Oxidation Activity ◽  
Microscopy Analysis

Upon infection, Mycobacterium leprae, an obligate intracellular bacillus, induces accumulation of cholesterol-enriched lipid droplets (LDs) in Schwann cells (SCs). LDs are promptly recruited to M. leprae-containing phagosomes, and inhibition of this process decreases bacterial survival, suggesting that LD recruitment constitutes a mechanism by which host-derived lipids are delivered to intracellular M. leprae. We previously demonstrated that M. leprae has preserved only the capacity to oxidize cholesterol to cholestenone, the first step of the normal cholesterol catabolic pathway. In this study we investigated the biochemical relevance of cholesterol oxidation on bacterial pathogenesis in SCs. Firstly, we showed that M. leprae increases the uptake of LDL-cholesterol by infected SCs. Moreover, fluorescence microscopy analysis revealed a close association between M. leprae and the internalized LDL-cholesterol within the host cell. By using Mycobacterium smegmatis mutant strains complemented with M. leprae genes, we demonstrated that ml1942 coding for 3β-hydroxysteroid dehydrogenase (3β-HSD), but not ml0389 originally annotated as cholesterol oxidase (ChoD), was responsible for the cholesterol oxidation activity detected in M. leprae. The 3β-HSD activity generates the electron donors NADH and NADPH that, respectively, fuel the M. leprae respiratory chain and provide reductive power for the biosynthesis of the dominant bacterial cell wall lipids phthiocerol dimycocerosate (PDIM) and phenolic glycolipid (PGL)-I. Inhibition of M. leprae 3β-HSD activity with the 17β-[N-(2,5-di-t-butylphenyl)carbamoyl]-6-azaandrost-4-en-3one (compound 1), decreased bacterial intracellular survival in SCs. In conclusion, our findings confirm the accumulation of cholesterol in infected SCs and its potential delivery to the intracellular bacterium. Furthermore, we provide strong evidence that cholesterol oxidation is an essential catabolic pathway for M. leprae pathogenicity and point to 3β-HSD as a prime drug target that may be used in combination with current multidrug regimens to shorten leprosy treatment and ameliorate nerve damage.

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.

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 Localization of cholesterol in sphingomyelinase-treated fibroblasts

1995 ◽  
Vol 308 (1) ◽  
pp. 269-274 ◽  
Author(s):  
M I Pörn ◽  
J P Slotte
Keyword(s):  
Plasma Membrane ◽  
Cell Surface ◽  
Staining Pattern ◽  
Cholesterol Oxidase ◽  
Cholesterol Oxidation ◽  
Cellular Cholesterol ◽  
Hypotonic Buffer ◽  
Induced Changes ◽  
Kinetics Of

The distribution of cellular unesterified cholesterol was studied in fibroblasts, which had been depleted of plasma membrane sphingomyelin by exposure to exogenous sphingomyelinase. This treatment has previously been shown to induce an increase in cholesterol esterification, a decrease in the biosynthesis of cholesterol, and a decreased susceptibility of cell cholesterol to oxidation with cholesterol oxidase. When the cellular localization of cholesterol was studied with fluorescent filipin staining, sphingomyelin depletion did not cause any visible changes in the filipin-cholesterol staining pattern, suggesting that the major part of cellular cholesterol was retained in the plasma membrane after sphingomyelinase treatment. After the oxidation of cell-surface cholesterol with cholesterol oxidase, the plasma membrane was no longer stained by filipin, but the plasma membrane cholesterol of sphingomyelin-depleted cells appeared to be resistant to oxidation with cholesterol oxidase when sphingomyelinase was used as an oxidation-promoting agent. However, the use of hypotonic buffer or phosphatidylcholine-specific phospholipase C together with cholesterol oxidase resulted in a complete oxidation of the cell-surface cholesterol in sphingomyelin-depleted cells, as evidenced by the filipin-cholesterol staining pattern. Similar results were obtained when [3H]cholesterol-labelled fibroblasts were used for determination of the susceptibility to cholesterol oxidation. The kinetics of [3H]cholesterol oxidation in sphingomyelin-depleted cells with cholesterol oxidase in hypotonic buffer indicated that approximately 85% of the cellular cholesterol still resided in the plasma membrane after sphingomyelin depletion. These results are contradictory to earlier reports on sphingomyelinase-induced changes in cellular cholesterol distribution and suggest that minor changes in the kinetics of cholesterol transport from the plasma membrane to the endoplasmic reticulum may be responsible for the sphingomyelinase-induced changes in the rates of cholesterol metabolism. Whereas the use of phospholipases to promote the oxidation of cholesterol in some instances might lead to misinterpretations, the use of hypotonic buffer together with cholesterol oxidase proved to be a more reliable method for the determination of cellular cholesterol distribution.

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