Alternative Pathways of Carbohydrate Utilization in Pseudomonads

1984 ◽  
Vol 38 (1) ◽  
pp. 359-388 ◽  
Author(s):  
T G Lessie ◽  
P V Phibbs
Keyword(s):  
Carbohydrate Utilization ◽  
Alternative Pathways

scholarly journals Identification of a Gene Cluster Enabling Lactobacillus casei BL23 To Utilize myo-Inositol

2007 ◽  
Vol 73 (12) ◽  
pp. 3850-3858 ◽  
Author(s):  
Mar�a Jes�s Yebra ◽  
Manuel Z��iga ◽  
Sophie Beaufils ◽  
Gaspar P�rez-Mart�nez ◽  
Josef Deutscher ◽  
...  
Keyword(s):  
Lactobacillus Casei ◽  
Protein A ◽  
Transcriptional Repressor ◽  
Catabolic Pathway ◽  
Gene Encoding ◽  
Carbohydrate Utilization ◽  
Alternative Pathways ◽  
Semialdehyde Dehydrogenase ◽  
Catabolite Control Protein A ◽  
Dna Insertion

ABSTRACT Genome analysis of Lactobacillus casei BL23 revealed that, compared to L. casei ATCC 334, it carries a 12.8-kb DNA insertion containing genes involved in the catabolism of the cyclic polyol myo-inositol (MI). Indeed, L. casei ATCC 334 does not ferment MI, whereas strain BL23 is able to utilize this carbon source. The inserted DNA consists of an iolR gene encoding a DeoR family transcriptional repressor and a divergently transcribed iolTABCDG1G2EJK operon, encoding a complete MI catabolic pathway, in which the iolK gene probably codes for a malonate semialdehyde decarboxylase. The presence of iolK suggests that L. casei has two alternative pathways for the metabolism of malonic semialdehyde: (i) the classical MI catabolic pathway in which IolA (malonate semialdehyde dehydrogenase) catalyzes the formation of acetyl-coenzyme A from malonic semialdehyde and (ii) the conversion of malonic semialdehyde to acetaldehyde catalyzed by the product of iolK. The function of the iol genes was verified by the disruption of iolA, iolT, and iolD, which provided MI-negative strains. By contrast, the disruption of iolK resulted in a strain with no obvious defect in MI utilization. Transcriptional analyses conducted with different mutant strains showed that the iolTABCDG1G2EJK cluster is regulated by substrate-specific induction mediated by the inactivation of the transcriptional repressor IolR and by carbon catabolite repression mediated by the catabolite control protein A (CcpA). This is the first example of an operon for MI utilization in lactic acid bacteria and illustrates the versatility of carbohydrate utilization in L. casei BL23.

Gene expression during two alternative pathways of ovary development in Pisum sativum: fruit development and ovary senescence

1992 ◽  
Vol 85 (1) ◽  
pp. 69-76 ◽  
Author(s):  
Maria-Jose Sanchez-Beltran ◽  
Juan Carbonell ◽  
Jose L. Garcia-Martinez ◽  
Isabel Lopez-Diaz
Keyword(s):  
Gene Expression ◽  
Pisum Sativum ◽  
Fruit Development ◽  
Ovary Development ◽  
Alternative Pathways ◽  
Ovary Senescence

Neuroplasticity

2019 ◽  
pp. 230-260
Author(s):  
Judy S. Reilly ◽  
Lara R. Polse
Keyword(s):  
Neural Plasticity ◽  
Late Onset ◽  
Neural Substrates ◽  
Brain Regions ◽  
Developing Brain ◽  
Perinatal Stroke ◽  
Alternative Pathways ◽  
Affective Expression ◽  
Unilateral Brain ◽  
Irreparable Damage

With respect to language, it has long been observed that children who experience early unilateral brain injury do not show the same irreparable damage as do adults with homologous late-onset strokes. Neural plasticity has been proposed as the explanation for such differential linguistic profiles; that is, the plasticity of the young, developing brain allows the possibility for extensive adaptation and organization following a neural insult. Recent research, however, suggests that there are limits to this ability to adapt and organize. Results from a another communicative system, affect, suggest that children with unilateral pre- or perinatal stroke show similar (albeit subtler) effects to adults with homologous late-onset injuries. This chapter presents findings on language development in children who sustained a pre- or perinatal unilateral stroke, and complements these studies with a discussion of affective expression in these same children. These prospective studies of children with perinatal stroke provide a unique window into the development of the neural substrates for language and affect. Specifically, they afford a context to investigate the degree to which particular brain regions may be privileged for specific behavioral functions, as well as how the developing brain adapts to organize alternative pathways in the wake of an early insult.

scholarly journals Quantifying fluorescent glycan uptake to elucidate strain-level variability in foraging behaviors of rumen bacteria

Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Leeann Klassen ◽  
Greta Reintjes ◽  
Jeffrey P. Tingley ◽  
Darryl R. Jones ◽  
Jan-Hendrik Hehemann ◽  
...  
Keyword(s):  
Metabolic Pathways ◽  
Ex Vivo ◽  
Rapid Assessment ◽  
Vital Role ◽  
Strain Level ◽  
Metabolic Phenotype ◽  
Specific Cell ◽  
Bacterial Cells ◽  
Carbohydrate Utilization

AbstractGut microbiomes, such as the microbial community that colonizes the rumen, have vast catabolic potential and play a vital role in host health and nutrition. By expanding our understanding of metabolic pathways in these ecosystems, we will garner foundational information for manipulating microbiome structure and function to influence host physiology. Currently, our knowledge of metabolic pathways relies heavily on inferences derived from metagenomics or culturing bacteria in vitro. However, novel approaches targeting specific cell physiologies can illuminate the functional potential encoded within microbial (meta)genomes to provide accurate assessments of metabolic abilities. Using fluorescently labeled polysaccharides, we visualized carbohydrate metabolism performed by single bacterial cells in a complex rumen sample, enabling a rapid assessment of their metabolic phenotype. Specifically, we identified bovine-adapted strains of Bacteroides thetaiotaomicron that metabolized yeast mannan in the rumen microbiome ex vivo and discerned the mechanistic differences between two distinct carbohydrate foraging behaviors, referred to as “medium grower” and “high grower.” Using comparative whole-genome sequencing, RNA-seq, and carbohydrate-active enzyme fingerprinting, we could elucidate the strain-level variability in carbohydrate utilization systems of the two foraging behaviors to help predict individual strategies of nutrient acquisition. Here, we present a multi-faceted study using complimentary next-generation physiology and “omics” approaches to characterize microbial adaptation to a prebiotic in the rumen ecosystem.

scholarly journals Estrogens and Progestogens in Triple Negative Breast Cancer: Do They Harm?

Cancers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2506
Author(s):  
Mark van Barele ◽  
Bernadette A. M. Heemskerk-Gerritsen ◽  
Yvonne V. Louwers ◽  
Mijntje B. Vastbinder ◽  
John W. M. Martens ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Triple Negative ◽  
Hormone Replacement ◽  
Breast Cancers ◽  
Younger Women ◽  
Alternative Pathways ◽  
Increased Risk ◽  
History Of ◽  
Hormone Sensitive

Triple-negative breast cancers (TNBC) occur more frequently in younger women and do not express estrogen receptor (ER) nor progesterone receptor (PR), and are therefore often considered hormone-insensitive. Treatment of premenopausal TNBC patients almost always includes chemotherapy, which may lead to premature ovarian insufficiency (POI) and can severely impact quality of life. Hormone replacement therapy (HRT) is contraindicated for patients with a history of hormone-sensitive breast cancer, but the data on safety for TNBC patients is inconclusive, with a few randomized trials showing increased risk-ratios with wide confidence intervals for recurrence after HRT. Here, we review the literature on alternative pathways from the classical ER/PR. We find that for both estrogens and progestogens, potential alternatives exist for exerting their effects on TNBC, ranging from receptor conversion, to alternative receptors capable of binding estrogens, as well as paracrine pathways, such as RANK/RANKL, which can cause progestogens to indirectly stimulate growth and metastasis of TNBC. Finally, HRT may also influence other hormones, such as androgens, and their effects on TNBCs expressing androgen receptors (AR). Concluding, the assumption that TNBC is completely hormone-insensitive is incorrect. However, the direction of the effects of the alternative pathways is not always clear, and will need to be investigated further.

scholarly journals Effects of carbon concentration, oxygen, and controlled pH on the engineering strain Lactiplantibacillus casei E1 in the production of bioethanol from sugarcane molasses

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Song Wang ◽  
Ran Tian ◽  
Buwei Liu ◽  
Hongcai Wang ◽  
Jun Liu ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
High Performance ◽  
Ethanol Yield ◽  
Starter Culture ◽  
Market Price ◽  
Sugarcane Molasses ◽  
Engineering Strain ◽  
Carbohydrate Utilization ◽  
Cane Molasses

AbstractSugarcane molasses are considered a potential source for bioethanol’s commercial production because of its availability and low market price. It contains high concentrations of fermentable sugars that can be directly metabolized by microbial fermentation. Heterofermentative lactic acid bacteria, especially Lactiplantibacillus casei, have a high potential to be a biocatalyst in ethanol production that they are characterized by strong abilities of carbohydrate metabolism, ethanol synthesis, and high alcohol tolerance. This study aimed to evaluate the feasibility of producing ethanol by Lactiplantibacillus casei used the ethanologen engineering strain L. casei E1 as a starter culture and cane molasses as substrate medium. The effects of environmental factors on the metabolism of L. casei E1 were analyzed by high-performance liquid chromatography (HPLC) system, and the gene expression of key enzymes in carbon source metabolism was detected using quantitative real-time PCR (RT–qPCR). Results showed that the strain could grow well, ferment sugar quickly in cane molasses. By fermenting this bacterium anaerobically at 37 °C for 36 h incubation in 5 °BX molasses when the fermenter’s pH was controlled at 6.0, ethanol yield reached 13.77 g/L, and carbohydrate utilization percentage was 78.60%. RT-qPCR results verified the strain preferentially ferment glucose and fructose of molasses to ethanol at the molecular level. In addition, the metabolism of sugars, especially fructose, would be inhibited by elevating acidity. Our findings support the theoretical basis for exploring Lactic acid bacteria as a starter culture for converting sugarcane molasses into ethanol.

Preparing African students with refugee backgrounds for transition: School practices

2021 ◽  
pp. 000494412199746
Author(s):  
Tebeje Molla
Keyword(s):  
Career Planning ◽  
Life Course Perspective ◽  
Student Agency ◽  
Government Schools ◽  
Institutional Practices ◽  
African Students ◽  
Career Support ◽  
School Practices ◽  
Alternative Pathways ◽  
Career Trajectories

For young people, the end of secondary school represents a critical transition point. This article aims at understanding how schools support a particular group of disadvantaged students to transition into education, training, or employment. Drawing on a life-course perspective and with refugee-background African students as an empirical focus, this qualitative case study documents career support practices in nine government schools in the State of Victoria. The findings show that schools provide transition opportunities that support African students to envision their post-school educational and career trajectories. The arrangements include career planning, alternative pathways, and employment of community engagement officers. However, there are persisting challenges that impede this group of students from fully benefiting from these arrangements. The main barriers identified here are academic disengagement, doxic aspirations, misconceptions about qualifications, and low self-efficacy. The article also argues that the persistence of these challenges is attributable at least in part to such overlooked factors of engagement as institutional practices, student agency, and home environment.

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