scholarly journals Physiology of yeast strains isolated from Brazilian biomes in a minimal medium using fructose as the sole carbon source reveals potential biotechnological applications

3 Biotech ◽  
2019 ◽  
Vol 9 (5) ◽  
Author(s):  
Cinthia Aparecida de Andrade Silva ◽  
Marta Lígia Oka ◽  
Gustavo Graciano Fonseca
2014 ◽  
Vol 80 (21) ◽  
pp. 6677-6684 ◽  
Author(s):  
Youyun Liang ◽  
Tong Si ◽  
Ee Lui Ang ◽  
Huimin Zhao

ABSTRACTSeveral yeast strains have been engineered to express different cellulases to achieve simultaneous saccharification and fermentation of lignocellulosic materials. However, successes in these endeavors were modest, as demonstrated by the relatively low ethanol titers and the limited ability of the engineered yeast strains to grow using cellulosic materials as the sole carbon source. Recently, substantial enhancements to the breakdown of cellulosic substrates have been observed when lytic polysaccharide monooxygenases (LPMOs) were added to traditional cellulase cocktails. LPMOs are reported to cleave cellulose oxidatively in the presence of enzymatic electron donors such as cellobiose dehydrogenases. In this study, we coexpressed LPMOs and cellobiose dehydrogenases with cellobiohydrolases, endoglucanases, and β-glucosidases inSaccharomyces cerevisiae. These enzymes were secreted and docked onto surface-displayed miniscaffoldins through cohesin-dockerin interaction to generate pentafunctional minicellulosomes. The enzymes on the miniscaffoldins acted synergistically to boost the degradation of phosphoric acid swollen cellulose and increased the ethanol titers from our previously achieved levels of 1.8 to 2.7 g/liter. In addition, the newly developed recombinant yeast strain was also able to grow using phosphoric acid swollen cellulose as the sole carbon source. The results demonstrate the promise of the pentafunctional minicellulosomes for consolidated bioprocessing by yeast.


Microbiology ◽  
2011 ◽  
Vol 157 (11) ◽  
pp. 3180-3186 ◽  
Author(s):  
Sandeep K. Sharma ◽  
The Su Moe ◽  
Ranjana Srivastava ◽  
Deepak Chandra ◽  
Brahm S. Srivastava

The nonadhesive mutant CD11 of Vibrio cholerae El Tor, defective in expression of mannose-sensitive haemagglutinin, lacks a protein when compared with its parent strain. Determination of the amino acid sequence revealed the identity of the protein as the product of VC1929, which is annotated to encode a protein, DctP, involved in the transport of C4-dicarboxylates. We cloned the dctP gene in pUC19 vector and expressed it in mutant CD11. Expression of DctP in the resulting complemented strain restored virulence, adhesive and colonizing capabilities, mannose-sensitive haemagglutination (MSHA) and ability to grow in medium containing sialic acid as a sole carbon source. The mutation in CD11 was caused by insertion of an adenine nucleotide in the reading frame of dctP. Recombinant purified DctP protein showed MSHA of human red blood cells, and protected rabbits against infection by V. cholerae. The protein was localized in membrane and cell wall fractions. The mutant, recombinant CD11 expressing DctP and parent strains were grown in M9 minimal medium in the presence of various carbohydrates (glucose, malate, fumarate, succinate or N-acetylneuraminic acid). The mutant was unable to grow in minimal medium containing N-acetylneuraminic acid (sialic acid) as the sole carbon source whereas the recombinant and parent strains utilized all the sugars tested. It is concluded that DctP is a mannose-sensitive haemagglutinin and a virulence factor and is involved in the utilization of sialic acid.


2009 ◽  
Vol 61 (2) ◽  
pp. 159-164 ◽  
Author(s):  
B. Jovcic ◽  
Jelena Begovic ◽  
Jelena Lozo ◽  
L. Topisirovic ◽  
Milan Kojic

Pseudomonas sp. ATCC19151 harbors a gene encoding a putative alkylsulfatase (sdsA). Here we report a growth ability of this strain in minimal media containing 0.5, 0.75, and 1% sodium dodecyl sulfate as the sole carbon source. The most prominent growth was detected for the minimal medium with 0.5% SDS, so this concentration of SDS was used to monitor Pseudomonas sp. ATCC19151 SDS biodegradation dynamics. Bacterial growth coincided with the disappearance of SDS. Antibiotic susceptibility was tested as well. Pseudomonas sp. ATCC19151 was resistant to six out of nine tested antibiotics, including ampicillin, tetracycline, chloramphenicol, tobramycin, nalidixic acid, and gentamycin.


2006 ◽  
Vol 188 (18) ◽  
pp. 6622-6628 ◽  
Author(s):  
Andrew T. Anfora ◽  
Rodney A. Welch

ABSTRACTd-Serine is an amino acid present in mammalian urine that is inhibitory toEscherichia colistrains lacking a functionaldsdAgene. Counterintuitively, adsdAstrain ofE. coliclinical isolate CFT073 hypercolonizes the bladder and kidneys of mice relative to wild type during a coinfection in the murine model of urinary tract infection. We are interested in the mechanisms for uptake ofd-serine in CFT073.d-Serine entersE. coliK-12 via CycA, thed-alanine transporter andd-cycloserine sensitivity locus. CFT073cycAcan grow on minimal medium withd-serine as a sole carbon source. ThedsdXgene of thedsdCXAlocus is a likely candidate for an additionald-serine transporter based on its predicted amino acid sequence similarity to gluconate transporters. In minimal medium, CFT073dsdXcan grow ond-serine as a sole carbon source; however, CFT073dsdX cycAcannot. Additionally, CFT073dsdXA cycAis not sensitive to inhibitory concentrations ofd-serine during growth on glycerol andd-serine minimal medium.d-[14C]serine uptake experiments with CFT073dsdX cycAharboringdsdXorcycArecombinant plasmids confirm thatd-serine is able to enterE. colicells via CycA or DsdX. In whole-celld-[14C]serine uptake experiments, DsdX has an apparentKmof 58.75 μM and aVmaxof 75.96 nmol/min/mg, and CycA has an apparentKmof 82.40 μM and aVmaxof 58.90 nmol/min/mg. Onlyd-threonine marginally inhibits DsdX-mediatedd-serine transport, whereasd-alanine, glycine, andd-cycloserine inhibit CycA-mediatedd-serine transport. DsdX or CycA is sufficient to transport physiological quantities ofd-serine, but DsdX is ad-serine-specific permease.


2016 ◽  
Vol 26 (5) ◽  
pp. 320-332 ◽  
Author(s):  
Meriem Derkaoui ◽  
Ana Antunes ◽  
Jamila Nait Abdallah ◽  
Sandrine Poncet ◽  
Alain Mazé ◽  
...  

We identified the genes encoding the proteins for the transport of glucose and maltose in <i>Neisseria meningitidis</i> strain 2C4-3. A mutant deleted for <i>NMV_1892</i><i>(glcP)</i> no longer grew on glucose and deletion of <i>NMV_0424</i><i>(malY)</i> prevented the utilization of maltose. We also purified and characterized glucokinase and α-phosphoglucomutase, which catalyze early catabolic steps of the two carbohydrates. <i>N. meningitidis</i> catabolizes the two carbohydrates either via the Entner-Doudoroff (ED) pathway or the pentose phosphate pathway, thereby forming glyceraldehyde-3-P and either pyruvate or fructose-6-P, respectively. We purified and characterized several key enzymes of the two pathways. The genes required for the transformation of glucose into gluconate-6-P and its further catabolism via the ED pathway are organized in two adjacent operons. <i>N. meningitidis</i> also contains genes encoding proteins which exhibit similarity to the gluconate transporter <i>(NMV_2230)</i> and gluconate kinase <i>(NMV_2231)</i> of Enterobacteriaceae and Firmicutes. However, gluconate might not be the real substrate of <i>NMV_2230</i> because <i>N. meningitidi</i>s was not able to grow on gluconate as the sole carbon source. Surprisingly, deletion of <i>NMV_2230</i> stimulated growth in minimal medium in the presence and absence of glucose and drastically slowed the clearance of <i>N. meningitidis</i> cells from transgenic mice after intraperitoneal challenge.


Author(s):  
B. L. Soloff ◽  
T. A. Rado

Mycobacteriophage R1 was originally isolated from a lysogenic culture of M. butyricum. The virus was propagated on a leucine-requiring derivative of M. smegmatis, 607 leu−, isolated by nitrosoguanidine mutagenesis of typestrain ATCC 607. Growth was accomplished in a minimal medium containing glycerol and glucose as carbon source and enriched by the addition of 80 μg/ ml L-leucine. Bacteria in early logarithmic growth phase were infected with virus at a multiplicity of 5, and incubated with aeration for 8 hours. The partially lysed suspension was diluted 1:10 in growth medium and incubated for a further 8 hours. This permitted stationary phase cells to re-enter logarithmic growth and resulted in complete lysis of the culture.


Author(s):  
Vivek Kumar Ranjan ◽  
Shriparna Mukherjee ◽  
Subarna Thakur ◽  
Krutika Gupta ◽  
Ranadhir Chakraborty

2008 ◽  
Vol 5 (4) ◽  
pp. 367-374 ◽  
Author(s):  
Jing Wang ◽  
Guiwen Yan ◽  
Mingquan An ◽  
Jieli Liu ◽  
Houming Zhang ◽  
...  

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