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Transformation of Natural Products by Marine-Derived Microorganisms
Published in Se-Kwon Kim, Marine Biochemistry, 2023
Thayane Melo de Queiroz, André Luiz Meleiro Porto
De Lise and co-workers (2016) described the isolation, recombinant expression in E. coli, and partial characterisation of a α-L-rhamnosidase (α-RHA) obtained from the marine bacteria Novosphingobium sp. PP1Y, which was isolated from surface seawater (Italy). In this study, the α-RHA enzyme was used in the hydrolysis of the flavonoids naringin, rutin, and neohesperidin dihydrochalcone into their glycosylated derivatives. The reactions were performed in Na-phosphate buffer (pH 7.0) under magnetic stirring at 40°C for 1–3 hours (Figure 5.9).
Cholestatic liver diseases
Published in Nizar Zein, Bret Lashner, The Year in Gastroenterology and Hepatology, 2005
B A C K G R o u N D Infectious agents and environmental toxins have been proposed as immunologicaltriggers for primary biliary cirrhosis (PBC) through molecular mimicry, the sharing of epitopes on proteins from unrelated species, resulting in the disruption of tolerance to self-antigens. The purpose of this study was to examine the immunological reactivity of a group of PBC patients to the bacterium Novosphingobium aromaticivorans in order to investigate whether this organism may play a role in the development of PBC. I N T E R P R E T A T I o N The authors concluded, on the basis o protein homology and the f ability to metabolize xenobiotics and to modulate oestrogen, the presence of the organism in faeces, and a specific immunological response in PBC patients, that N. aromaticivorans may play a role in the induction of PBC.
Distribution and Diversity of Ocular Microbial Communities in Diabetic Patients Compared with Healthy Subjects
Published in Current Eye Research, 2018
Baknoon Ham, Hyung Bin Hwang, Sang Hoon Jung, Sungyul Chang, Kui Dong Kang, Man Jae Kwon
To analyze the significance of the difference in the bacterial distribution between the diabetic patients and control subjects, linear discriminant analysis effect size (LEfse)29 analysis was used (at a P-value of 0.05). An LDA score > 2.6 was considered a significant result. At the phylum level, Proteobacteria were overrepresented in the diabetic group (LDA score = 5.3), whereas Firmicutes and Cyanobacteria were overrepresented in the control group (LDA score = 5.0 and 4.9) (Figure 5A). At the genus level, Acinetobacter, Burkholderia, Rheinheimera, and Micrococcus were overrepresented in the diabetic group (LDA score > 3.6), and Staphylococcus, Bradyrhizobiaceae, Streptophyta, and Novosphingobium were more prevalent in the healthy subjects (LDA score > 3.0) (Figure 5B).
Completion of the gut microbial epi-bile acid pathway
Published in Gut Microbes, 2021
Heidi L. Doden, Patricia G. Wolf, H. Rex Gaskins, Karthik Anantharaman, João M. P. Alves, Jason M. Ridlon
The sequence WP_007678535.1 from Novosphingobium sp. AP12, whose recombinant enzyme product did not exhibit bile acid 12β-HSDH activity with the substrates tested, may be specific for aerobic bile acid degradation products. Environmental microorganisms, such as Comamonas testosteroni TA441 and Pseudomonas sp. strain Chol1, encode a CA degradation pathway involving conversion of a 12-oxo-intermediate to 7α,12β-dihydroxy-androsta-1,4-diene-3,17-dione (12β-DHADD).63,64 Thus, sequences in the extension of the subtree may have 12β-HSDH activity, but with specificity for side-chain cleaved steroids rather than bile acids.
Intraguild predation between Pristionchus pacificus and Caenorhabditis elegans: a complex interaction with the potential for aggressive behaviour
Published in Journal of Neurogenetics, 2020
Kathleen T. Quach, Sreekanth H. Chalasani
Presented with an excess of larval C. elegans in the absence of bacteria, the standard P. pacificus laboratory strain PS312 readily bites larval prey, with about 34\% of bites resulting in killed corpses (Wilecki et al., 2015). However, the same study noted that only about half of larvae corpses were eaten and surmised that surplus killing by P. pacificus may serve to eliminate competition. Although intraguild predation was not explicitly mentioned in (Wilecki et al., 2015), the metric of uneaten killed prey once again raises the question of whether a non-predatory component is behind the motivation for killing prey. It still remains to be demonstrated whether or not competition is in fact the non-predatory motivation in question. Recent findings reveal that the level of surplus killing by P. pacificus is influenced by the nutrient composition of its bacterial diet (Akduman et al., 2019). Specifically, B12 derived from the bacterial strain Novosphingobium L76 was found to double the killing efficiency of P. pacificus without co-ordinately increasing feeding rate. Pristionchus pacificus raised on a Novosphingobium L76 diet versus an E. coli OP50 diet exhibited differential expression of genes involved in fatty acid metabolism. Thus, in addition to bacterial preference, physiological changes induced by bacterial diet also affect predatory behaviour. In order to design contexts that may potentially discourage predation for eating prey and instead promote competition against C. elegans for bacteria, multiple bacterial variables such as abundance, preference, caloric value, and nutrient composition can be individually manipulated. How killing efficiency and surplus killing changes across bacterial conditions may provide answers to the question of whether competition can motivate P. pacificus to bite C. elegans in conditions that exacerbate competition for bacterial food.