Metabolomics of the bio-degradation process of aflatoxin B1 by actinomycetes at an initial pH of 6.0

Contamination of food and feed by Aflatoxin B1 (AFB1) is a cause of serious economic and health problems. Different processes have been used to degrade AFB1. In this study, biological degradation of AFB1 was carried out using three Actinomycete species, Rhodococcus erythropolis ATCC 4277, Streptomyces lividans TK 24, and S. aureofaciens ATCC 10762, in liquid cultures. Biodegradation of AFB1 was optimised under a range of temperatures from 25 to 40 °C and pH values of 4.0 to 8.0. An initial concentration of 20 µg/mL of AFB1 was used in this study. The amount of AFB1 remaining was measured against time by thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC), coupled with UV and mass spectrometry (LC-MS). All species were able to degrade the AFB1, and no significant difference was found between them. AFB1 remained in the liquid culture for R. erythropolis, S. lividans and S. aureofaciens were 0.81 µg/mL, 2.41 µg/mL and 2.78 µg/mL respectively, at the end of the first 24 h. Degradation occurred at all incubation temperatures and the pH with the optimal conditions for R. erythropolis was achieved at 30 °C and pH 6, whereas for S. lividans and S. aureofaciens the optimum conditions for degradation were 30 °C and pH 5. Analysis of the degradative route indicated that each microorganism has a different way of degrading AFB1. The metabolites produced by R. erythropolis were significantly different from the other two microorganisms. Products of degradation were identified through metabolomic studies by utilizing high-resolution mass spectral data. Mass spectrometric analysis indicated that the degradation of AFB1 was associated with the appearance of a range of lower molecular weight compounds. The pathway of degradation or chemical alteration of AFB1 was followed by means of high resolution Fourier transform mass spectrometry (HR-FTMS) analysis as well as through the MS2 fragmentation to unravel the degradative pathway for AFB1. AFB1 bio-degradation was coupled with the accumulation of intermediates of fatty acid metabolism and glycolysis. A plausible mechanism of degradation of AFB1 by Rhodococcus was hypothesized

The Pichia pastoris transmembrane protein GT1 is a glycerol transporter and relieves the repression of glycerol on AOX1 expression

Promoter of alcohol oxidase I (PAOX1) is the most efficient promoter involved in the regulation of recombinant protein expression in Pichia pastoris (P. pastoris). PAOX1 is tightly repressed by the presence of glycerol in the culture medium; thus, glycerol must be exhausted before methanol can be taken up by P. pastoris and the expression of the heterologous protein can be induced. In this study, a candidate glycerol transporter (GT1, GeneID: 8197545) was identified, and its role was confirmed by further studies (e.g. bioinformatics analysis, heterologous complementation in Schizosaccharomyces pombe (S. pombe)). When GT1 is co-expressed with enhanced green fluorescent protein (EGFP), it localizes to the membrane and S. pombe carrying gt1 but not the wild-type strain can grow on medium containing glycerol as the sole carbon source. The present study is the first to report that AOX1 in the X-33gt1 mutant can achieve constitutive expression in medium containing glycerol; thus, knocking down gt1 can eliminate the glycerol repression of PAOX1 in P. pastoris. These results suggest that the glycerol transporter may participate in the process of PAOX1 inhibition in glycerol medium

Antimicrobial properties and cytotoxicity of sulfated (1,3)-β-D-glucan from the mycelium of the mushroom Ganoderma lucidum

Ganoderma lucidum BCCM 31549 has a long established role for its therapeutic activities. In this context, much interest has focused on the possible functions of the (1,3)-β-D-glucan (G) produced by these cultures in a stirred-tank bioreactor and extracted from their underutilized mycelium. In the existing study, we report on the systematic production of G, and its sulfated derivative (GS). The aim of this study was to investigate the G and its GS from G. lucidum in terms of antibacterial properties, and cytotoxicity spectrum against Human-Prostate-Cell (PN2TA) and Human-Caucasian-Histiocytic-Lymphoma (U937). (1)H NMR for both G and GS compounds showed β-glycosidic linkages and structural similarities when compared with two standards (Laminarin and Fucoidan). The existence of characteristic absorptions at 1,170 and 867 cm(-1) in the FTIR for GS demonstrated the successful sulfation of G. Only GS exhibited antimicrobial activity against a varied range of test bacteria of relevance to foodstuffs and human health. Moreover, both G and GS did not show any cytotoxic effects on PN2TA cells, thus helping demonstrate the safety on these polymers. Also, GS shows 40% antiproliferation against cancerous U937 cells at low concentration (60 µg/mL) applied in this study compared to G (10%). Together, this demonstrates that sulfation clearly improved the solubility and therapeutic activities of G. The water-soluble GS demonstrates the potential multi-functional effects of these materials in foodstuffs

Rate of Decline in Nontreponemal Antibody Titers and Seroreversion After Treatment of Early Syphilis

Syphilis management is complex and demonstration of treatment response requires monitoring of nontreponemal antibody titers for a ≥ 4-fold decline and/or seroreversion to nonreactive titers

A Perceptual Comparison of Prosodic Features in Apraxia of Speech and Conduction Aphasia

TB

Consistency, Variability, and Target Approximation for Successive Speech Repetitions Among Apraxic, Conduction Aphasic, and Ataxic Dysarthric Speakers

TB

Exploring the Ambulatory Transitional Care Experience from Residential Aged Care Facilities (RACF) to Ambulatory Care Services

Objective(s): To explore the transitional care journey through Ambulatory care Services (ACS) for older residents from Residential Aged Care Facilities (RACF). To develop a clearer understanding of older residents needs and any gaps in current services provided; and to inform the development of a model of care to improve the resident’s transitional care journey Study Design: A qualitative project design using extensive stakeholder engagement Method: The Ambulatory Care (AC) experience was explored through semi-structured interviews with residents and their carers to determine gaps in transitional care continuity. Focus groups with RACF and ACS staff were also utilized. Journey mapping was used to support anecdotal evidence. Results: Three residents and 2 carers were interviewed and a total of 40 RACF and ACS staff attended 5 focus groups. Principal Findings: Qualitative data analysis identified four main themes across the transition journey: Inconsistent and adhoc communication; Just waiting around; Is it doing more harm than good?; and Unmet expectations.Conclusion: The results of this study have highlighted shortcomings in the provision of quality care in this transitional care group of older clients. A collaborative approach across organizational boundaries is necessary to ensure the development of an integrated person centered model to ensure the best transition to ambulatory care for RACF residents exists

Application of pharmacogenomics and bioinformatics to exemplify the utility of human <i>ex vivo</i> organoculture models in the field of precision medicine

Here we describe a collaboration between industry, the National Health Service (NHS) and academia that sought to demonstrate how early understanding of both pharmacology and genomics can improve strategies for the development of precision medicines. Diseased tissue ethically acquired from patients suffering from chronic obstructive pulmonary disease (COPD), was used to investigate inter-patient variability in drug efficacy using ex vivo organocultures of fresh lung tissue as the test system. The reduction in inflammatory cytokines in the presence of various test drugs was used as the measure of drug efficacy and the individual patient responses were then matched against genotype and microRNA profiles in an attempt to identify unique predictors of drug responsiveness. Our findings suggest that genetic variation in CYP2E1 and SMAD3 genes may partly explain the observed variation in drug response