scholarly journals Biosynthesis of Extracellular Polymeric Substances by the Marine BacteriumSaccharophagus degradansunder Different Nutritional Conditions

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Yolanda González-García ◽  
Alejandra Heredia ◽  
Juan Carlos Meza-Contreras ◽  
Froylán M. E. Escalante ◽  
Rosa María Camacho-Ruiz ◽  
...  
Keyword(s):  
Carbon Source ◽  
Synergistic Effect ◽  
Maximum Concentration ◽  
Marine Bacterium ◽  
Extracellular Polymeric Substances ◽  
Mineral Medium ◽  
Saccharophagus Degradans ◽  
First Report ◽  
Nutritional Conditions ◽  
New Feature

The effect of carbon source, carbon to nitrogen (C/N) ratio, and limitation in nutrients (N, P, K, Ca, Mg, and Fe) on extracellular polymeric substances (EPS) synthesis by the marine bacteriumSaccharophagus degradanswas studied. This strain was able to grow in mineral medium and produce EPS with different efficiency according to the C source used (g EPS/L): glucose or starch (1.5 ± 0.2); galactose, sucrose, or xylose (0.7 ± 0.2); and fructose (0.3 ± 0.1). The C/N ratio (glucose/ammonium) had a significant effect on EPS biosynthesis due to its production rise as the C/N ratio increased from 3 to 100 (0.7 to 2.1 g EPS/L). It was also observed that limitation in nutrients such as N, P, K, Ca, Mg, and Fe also favored EPS biosynthesis. When taking into account both factors (C/N ratio, 100; nutrients limitation, 50%) a positive synergistic effect was noted on EPS production since under these conditions the maximum concentration obtained was 4.12 ± 0.3 g/L after 72 h of culture. The polymer was found to be a polysaccharide of mainly glucose, mannose, and galactose. This is the first report on EPS production byS. degradanswhich is a new feature of this versatile marine bacterium.

scholarly journals A Novel Glycoside Hydrolase Family 5 β-1,3-1,6-Endoglucanase from Saccharophagus degradans 2-40Tand Its Transglycosylase Activity

2016 ◽  
Vol 82 (14) ◽  
pp. 4340-4349 ◽  
Author(s):  
Damao Wang ◽  
Do Hyoung Kim ◽  
Nari Seo ◽  
Eun Ju Yun ◽  
Hyun Joo An ◽  
...  
Keyword(s):  
Glycoside Hydrolase ◽  
Marine Bacterium ◽  
Enzymatic Reaction ◽  
Glycoside Hydrolase Family ◽  
Reaction Products ◽  
Brown Macroalgae ◽  
Fungal Cell ◽  
Content Type ◽  
Saccharophagus Degradans ◽  
Hydrolase Family

ABSTRACTIn this study, we characterized Gly5M, originating from a marine bacterium, as a novel β-1,3-1,6-endoglucanase in glycoside hydrolase family 5 (GH5) in the Carbohydrate-Active enZyme database. Thegly5Mgene encodes Gly5M, a newly characterized enzyme from GH5 subfamily 47 (GH5_47) inSaccharophagus degradans2-40T. Thegly5Mgene was cloned and overexpressed inEscherichia coli. Through analysis of the enzymatic reaction products by thin-layer chromatography, high-performance liquid chromatography, and matrix-assisted laser desorption ionization–tandem time of flight mass spectrometry, Gly5M was identified as a novel β-1,3-endoglucanase (EC 3.2.1.39) and bacterial β-1,6-glucanase (EC 3.2.1.75) in GH5. The β-1,3-endoglucanase and β-1,6-endoglucanase activities were detected by using laminarin (a β-1,3-glucan with β-1,6-glycosidic linkages derived from brown macroalgae) and pustulan (a β-1,6-glucan derived from fungal cell walls) as the substrates, respectively. This enzyme also showed transglycosylase activity toward β-1,3-oligosaccharides when laminarioligosaccharides were used as the substrates. Since laminarin is the major form of glucan storage in brown macroalgae, Gly5M could be used to produce glucose and laminarioligosaccharides, using brown macroalgae, for industrial purposes.IMPORTANCEIn this study, we have discovered a novel β-1,3-1,6-endoglucanase with a unique transglycosylase activity, namely, Gly5M, from a marine bacterium,Saccharophagus degradans2-40T. Gly5M was identified as the newly found β-1,3-endoglucanase and bacterial β-1,6-glucanase in GH5. Gly5M is capable of cleaving glycosidic linkages of both β-1,3-glucans and β-1,6-glucans. Gly5M also possesses a transglycosylase activity toward β-1,3-oligosacchrides. Due to the broad specificity of Gly5M, this enzyme can be used to produce glucose or high-value β-1,3- and/or β-1,6-oligosaccharides.

ROS-responsive organosilica nanocarrier for targeting-delivery of metformin against cancer with synergistic effect of hypoglycemia

2021 ◽  
Author(s):  
Yefei Yu ◽  
Jifeng Chen ◽  
Shuang Liu ◽  
Cheng Du
Keyword(s):  
Synergistic Effect ◽  
Silica Nanoparticles ◽  
Anticancer Therapy ◽  
First Report ◽  
Targeting Delivery ◽  
Controllable Degradation

The controllable degradation of silica nanoparticles in anticancer therapy remains challenging. Here, we offer the first report that thioketal (TK)-bond-containing bridge-organoakloxysilane has been synthesized. This allows for the fabrication of...

scholarly journals Isolation and Characterization of a Mutant of the Marine Bacterium Alcanivorax borkumensis SK2 Defective in Lipid Biosynthesis

2010 ◽  
Vol 76 (9) ◽  
pp. 2884-2894 ◽  
Author(s):  
Efraín Manilla-Pérez ◽  
Alvin Brian Lange ◽  
Stephan Hetzler ◽  
Marc Wältermann ◽  
Rainer Kalscheuer ◽  
...  
Keyword(s):  
Carbon Source ◽  
Sole Carbon Source ◽  
Marine Bacterium ◽  
Neutral Lipids ◽  
Nile Red ◽  
Dry Weight ◽  
Wax Ester ◽  
Gene Encoding ◽  
Isolation And Characterization ◽  
Key Enzyme

ABSTRACT In many microorganisms, the key enzyme responsible for catalyzing the last step in triacylglycerol (TAG) and wax ester (WE) biosynthesis is an unspecific acyltransferase which is also referred to as wax ester synthase/acyl coenzyme A (acyl-CoA):diacylglycerol acyltransferase (WS/DGAT; AtfA). The importance and function of two AtfA homologues (AtfA1 and AtfA2) in the biosynthesis of TAGs and WEs in the hydrocarbon-degrading marine bacterium Alcanivorax borkumensis SK2 have been described recently. However, after the disruption of both the AtfA1 and AtfA2 genes, reduced but substantial accumulation of TAGs was still observed, indicating the existence of an alternative TAG biosynthesis pathway. In this study, transposon-induced mutagenesis was applied to an atfA1 atfA2 double mutant to screen for A. borkumensis mutants totally defective in biosynthesis of neutral lipids in order to identify additional enzymes involved in the biosynthesis of these lipids. At the same time, we have searched for a totally TAG-negative mutant in order to study the function of TAGs in A. borkumensis. Thirteen fluorescence-negative mutants were identified on Nile red ONR7a agar plates and analyzed for their abilities to synthesize lipids. Among these, mutant 2 M131 was no longer able to synthesize and accumulate TAGs if pyruvate was used as the sole carbon source. The transposon insertion was localized in a gene encoding a putative cytochrome c family protein (ABO_1185). Growth and TAG accumulation experiments showed that the disruption of this gene resulted in the absence of TAGs in 2 M131 but that growth was not affected. In cells of A. borkumensis SK2 grown on pyruvate as the sole carbon source, TAGs represented about 11% of the dry weight of the cells, while in the mutant 2 M131, TAGs were not detected by thin-layer and gas chromatography analyses. Starvation and lipid mobilization experiments revealed that the lipids play an important role in the survival of the cells. The function of neutral lipids in A. borkumensis SK2 is discussed.

scholarly journals Draft Genome Sequence of Sphingobacterium sp. CZ-UAM, Isolated from a Methanotrophic Consortium

2017 ◽  
Vol 5 (33) ◽  
Author(s):  
José Luis Steffani-Vallejo ◽  
Cristal Zuñiga ◽  
Pablo Cruz-Morales ◽  
Luis Lozano ◽  
Marcia Morales ◽  
...  
Keyword(s):  
Carbon Source ◽  
Genome Sequence ◽  
Draft Genome ◽  
Mineral Medium ◽  
Draft Genome Sequence

ABSTRACT Sphingobacterium sp. CZ-UAM was isolated from a methanotrophic consortium in mineral medium using methane as the only carbon source. A draft genome of 5.84 Mb with a 40.77% G+C content is reported here. This genome sequence will allow the investigation of potential methanotrophy in this isolated strain.

Flocculation of Botryococcus Braunii with Glycine

2014 ◽  
Vol 1004-1005 ◽  
pp. 877-880 ◽  
Author(s):  
Xin Miao Xu ◽  
Chao Zhou Chen ◽  
Ying Shen
Keyword(s):  
Carbon Source ◽  
Extracellular Polymeric Substances ◽  
Mixing Time ◽  
Biomass Productivity ◽  
Botryococcus Braunii ◽  
Culture Period ◽  
Solid Concentration ◽  
Organic Carbon Source ◽  
Biomass Recovery ◽  
Low Levels

The objective of this paper was to optimize the flocculation and biomass productivity of Botryococcus braunii by using an organic carbon source glycine. The effects of culture period and glycine dose with high, medium and low levels on both solid concentration achieved and biomass productivity were conducted. It was found that extracellular polymeric substances (EPS), which promotes flocculation, was produced not only by bacterial but also by microalgae. The productivity of EPS was affected by culture period, glycine dose and mixing time. The maximum EPS of 103.3 mg/L obtained with 11 day culture period and 0.1 g/L glycine, leading to the maximum solid concentration achieved of 51 g/L, the biomass recovery rate 72%.

scholarly journals Engineering of a Xylose Metabolic Pathway in Corynebacterium glutamicum

2006 ◽  
Vol 72 (5) ◽  
pp. 3418-3428 ◽  
Author(s):  
Hideo Kawaguchi ◽  
Alain A. Vert�s ◽  
Shohei Okino ◽  
Masayuki Inui ◽  
Hideaki Yukawa
Keyword(s):  
Carbon Source ◽  
Corynebacterium Glutamicum ◽  
Xylose Isomerase ◽  
Mineral Medium ◽  
Gene Encoding ◽  
Xylose Consumption ◽  
E Coli ◽  
High Copy Number Plasmid ◽  
Sugar Mixture ◽  
Pentose Sugar

ABSTRACT The aerobic microorganism Corynebacterium glutamicum was metabolically engineered to broaden its substrate utilization range to include the pentose sugar xylose, which is commonly found in agricultural residues and other lignocellulosic biomass. We demonstrated the functionality of the corynebacterial xylB gene encoding xylulokinase and constructed two recombinant C. glutamicum strains capable of utilizing xylose by cloning the Escherichia coli gene xylA encoding xylose isomerase, either alone (strain CRX1) or in combination with the E. coli gene xylB (strain CRX2). These genes were provided on a high-copy-number plasmid and were under the control of the constitutive promoter trc derived from plasmid pTrc99A. Both recombinant strains were able to grow in mineral medium containing xylose as the sole carbon source, but strain CRX2 grew faster on xylose than strain CRX1. We previously reported the use of oxygen deprivation conditions to arrest cell replication in C. glutamicum and divert carbon source utilization towards product production rather than towards vegetative functions (M. Inui, S. Murakami, S. Okino, H. Kawaguchi, A. A. Vert�s, and H. Yukawa, J. Mol. Microbiol. Biotechnol. 7:182-196, 2004). Under these conditions, strain CRX2 efficiently consumed xylose and produced predominantly lactic and succinic acids without growth. Moreover, in mineral medium containing a sugar mixture of 5% glucose and 2.5% xylose, oxygen-deprived strain CRX2 cells simultaneously consumed both sugars, demonstrating the absence of diauxic phenomena relative to the new xylA-xylB construct, albeit glucose-mediated regulation still exerted a measurable influence on xylose consumption kinetics.

Anaerobic Degradation of PCP and Phenol in Fixed-Film Reactors: The Influence of an Additional Substrate

1991 ◽  
Vol 24 (3-4) ◽  
pp. 431-436 ◽  
Author(s):  
H. V. Hendriksen ◽  
S. Larsen ◽  
B. K. Ahring
Keyword(s):  
Sewage Sludge ◽  
Carbon Source ◽  
Anaerobic Degradation ◽  
Degradation Products ◽  
Phenol Degradation ◽  
Treatment Plant ◽  
Continuous Operation ◽  
Mineral Medium ◽  
Fixed Film ◽  
Digested Sewage Sludge

The anaerobic degradation of pentachlorophenol (PCP) and phenol was examined in two lab-scale fixed-film reactors. Anaerobic digested sewage sludge from a municipal treatment plant was used as inoculum. The reactors were fed a mineral medium containing PCP (1-2 mg/l) and phenol (4-6 mg/l). In addition one of the reactors received 1 g/l glucose as an easily degradable carbon source. After 6 months of continuous operation, the removal of PCP in the reactor with no glucose added was approximately 60%, whereas the removal in the reactor with glucose reached 98%. Tetrachlorophenol (TeCP) and trichloro-phenol (TCP) were found as degradation products and the removal of these compounds was also significantly enhanced by the presence of glucose. Phenol degradation was approximately 70% with glucose added and 95% without glucose.

Biosynthesis and characterization of polyhydroxyalkanoates in the polysaccharide-degrading marine bacterium Saccharophagus degradans ATCC 43961

2008 ◽  
Vol 35 (6) ◽  
pp. 629-633 ◽  
Author(s):  
Yolanda González-García ◽  
Jesús Nungaray ◽  
Jesús Córdova ◽  
Orfil González-Reynoso ◽  
Martin Koller ◽  
...  
Keyword(s):  
Marine Bacterium ◽  
Saccharophagus Degradans
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