Continuous citric acid secretion by a high specific pH dependent active transport system in yeast Candida oleophila ATCC 20177

The pH influence on continuous citric acid secretion was investigated in Candida oleophila ATCC 20177 (var.) under NH4+ limiting state steady conditions, using glucose. Highest citric acid concentration of 57.8 g/l, citrate/isocitrate ratio of 15.6, space-time yield of 0.96 g/(l x hr) and biomass specific productivity of 0.041 g/(g x hr) were obtained at pH 5 and 60 hrs residence time. Only 22.8 g/l (39.4%) and a ratio of 9.9 were achieved at pH 6 pH and 12.4 g/l (21.5%) and a ratio of 3.7 at pH 3. Under non producing conditions, in excess of nitrogen, biomass concentration increased at raising pH. An iron concentration of 200 ppm was determined in biomass of C. oleophila at pH 5, compared with only 26 ppm found at pH 3 (factor 7.7). Intra- and extracellular concentrations of citrates and glucose confirmed the existence of a high specific, pH dependent active transport system for citrate secretion, while isocitrate isn't a high-affine substrate, displaying a strong correlation with ATP/ADP ratio. Differences between extra- and intracellular concentration of citrate higher than 1 and up to about 60 were determined. The active transport systemfor citrate excretion appears to be the main speed-determining factor in citrate overproduction by yeasts

Oxygen and temperature effect on continuous citric acid secretion in Candida oleophila

The influence of air saturation and temperature on continuous citric acid secretion was studied in chemostat cultures of Candida oleophila ATCC 20177 (var.). Simultaneous measurements of intra- and extracellular concentration of glucose, citric and isocitric acid confirmed the involvement of a specific active transport system in citrate secretion, favouring citric acid over isocitrate. An optimum air oxygen saturation of 20% and temperature of 30-31\ub0C were determined for the continuous citric acid secretion. The highest values of citric acid concentration (98 g/L), citrate to isocitrate ratio (33.3:1), volumetric citric productivity (1.8 g/(L x h)), and specific citric acid productivity (0.1 g/(g x h)), were reached at 20% air saturation at a residence time of 54 hrs by the experiment's lowest biomass of 18 g/L. The highest isocitic acid volumetric productivity (55.6 mg/(L x h)) and specific productivity (0.99 mg/(g x h)) were identified at 50%, instead. The fastest citrate excretion rate of the generic product of 0.046 g/(g*h) was found at 30-31\ub0C. A concentration ratio between extra- and intracellular concentration of citrate of up to 9 was identified. The highest extra-/intracellular ratio of citrate and lowest intracellular concentrations of glucose, citric and isocitric acid were determined at optimum air saturation as a consequence of active citrate export

Continuous gluconic acid production by Aureobasidium pullulans with and without biomass retention

New alternative processes for the continuous production of gluconic acid by Aureobasidium pullulans , using biomass retention by cell immobilization or cross over filtration, are described in the present work. 315 g/l gluconic acid was continuously produced in chemostat cultures at 21 hrs residence time without any biomass retention. 260 g/l gluconic acid was produced in fluidized bed reactor at 21 hrs residence time. The support carrier was overgrown resulting in limitations of oxygen transfer towards the inner layers of immobilized biomass. 375 g/l gluconic acid was produced under continuous cultivation at 22 hrs of residence time with a formation rate for the generic product of 17 g/(l x h) and a specific gluconic acid productivity of only 0.74 g/(g x h), using biomass retention by cross over filtration. 370 g/l were obtained at 19 hrs RT and 100% conversion with 25 g/l biomass and a formation rate of 19 g/(l x h). At 100% conversion, a selectivity of only 78% was determined at 22 hrs and of 77% at 19 hrs RT, because of the very high biomass concentration. Biomass retention makes it possible to break the existing link between growth and residence time

Citric acid production from glucose by yeast Candida oleophila ATCC 20177 under batch, continuous and repeated batch cultivation

The effect of air saturation on citric acid production in batch, repeated batch and chemostat cultures has been studied. It was shown that, under continuous fermentation (chemostat mode), the highest concentration of citric acid equal of 98 g/l was produced at 20% of air saturation. In contrary to continuous fermentation, displaying an optimum at 20%, 80% air saturation yielded higher values in repeated batch fermentation process. 167 g/l citric acid were produced continuously with the fill and drain technique at 4.85 days, at 80% air saturation, compared with 157.6 g/l achieved within 5.4 days at 20%. Under repeated batch fermentation, the formation rate of the generic product (Rj) as well as the specific citric acid productivity (mp) reached a maximum of 1.283 g/(l x hr) at 4.01 days and of 0.0375 g/(g x hr) at 4.58 days, respectively. The glucose consumption rate (Rx) reached a maximum value of 3.33 g/(l x hr) entering stationary phase after 2.56 days at a glucose concentration of 131.2 g/l

Alcohol dependence and treatment utilization in Europe - a representative cross-sectional study in primary care

Alcohol dependence (AD) in Europe is prevalent and causes considerable health burden. Recognition by general practitioners (GPs) and provision of or referral to treatment may contribute to reduce this burden. This paper studied AD prevalence in varying European primary care settings and examined who received treatment

[Bere problematico e problemi di salute in Toscana e in Friuli Venezia Giulia: uno studio epidemiologico attraverso i medici di medicina generale]

"OBJECTIVES: to identify the differences among patients of general practictioners (GPs) in both Tuscany Region (Central Italy) and Friuli Venezia Giulia (FVG) Region (Northern Italy), which are different for drinking cultures, as to motivation of consultation, hazardous drinking and alcohol dependence, health problems, and use of health services

The post-COVID era : challenges in the treatment of substance use disorder (SUD) after the pandemic

Abstract Background Citizens affected by substance use disorders are high-risk populations for both SARS-CoV-2 infection and COVID-19-related mortality. Relevant vulnerabilities to COVID-19 in people who suffer substance use disorders are described in previous communications. The COVID-19 pandemic offers a unique opportunity to reshape and update addiction treatment networks. Main body Renewed treatment systems should be based on these seven pillars: (1) telemedicine and digital solutions, (2) hospitalization at home, (3) consultation-liaison psychiatric and addiction services, (4) harm-reduction facilities, (5) person-centered care, (6) promote paid work to improve quality of life in people with substance use disorders, and (7) integrated addiction care. The three “best buys” of the World Health Organization (reduce availability, increase prices, and a ban on advertising) are still valid. Additionally, new strategies must be implemented to systematically deal with (a) fake news concerning legal and illegal drugs and (b) controversial scientific information. Conclusion The heroin pandemic four decades ago was the last time that addiction treatment systems were updated in many western countries. A revised and modernized addiction treatment network must include improved access to care, facilitated where appropriate by technology; more integrated care with addiction specialists supporting non-specialists; and reducing the stigma experienced by people with SUDs

Alcohol dependence in the Italian general population: diagnostic criteria according to general practitioners and to the Composite International Diagnostic Interview (CIDI)

OBIETTIVI: identificare i criteri utilizzati dai medici di medicina ge- nerale (MMG) per le diagnosi di alcoldipendenza (AD) e confron- tarli con quelli dell\u2019intervista Composite International Diagnostic Interview (CIDI). DISEGNO: studio correlazionale trasversale. SETTING E PARTECIPANTI: i 55 MMG delle regioni Friuli Venezia Giulia e Toscana che hanno preso parte alla ricerca hanno effettuato una valutazione clinica dei primi 40 pazienti che si presentavano da loro per una visita medica. PRINCIPALI MISURE DI OUTCOME: tassi di alcoldipendenza diagnosti- cati dai MMG e dall\u2019intervista CIDI e loro relazione con le variabili sociodemografi la presenza di altre patologie e il consumo di alcol. RISULTATI: i MMG hanno diagnosticato l\u2019AD nel 5,4% dei casi e l\u2019intervista CIDI nel 4,4% dei casi, con una sovrapposizione del 26% circa. Rispetto al CIDI, i MMG hanno identifi come AD pa- zienti di et\ue0 pi\uf9 avanzata e affetti da malattie epatiche e ipertensione. CONCLUSIONI: la limitata sovrapposizione tra diagnosi di AD fatte dai MMG e dal CIDI \ue8 problematica. I MMG sembrano indivi- duare prevalentemente le forme di AD pi\uf9 gravi, in cui il consu- mo eccessivo di alcol \ue8 associato alla presenza di patologie epatiche, mentre il CIDI permette di individuare anche pazienti pi\uf9 giovani che non hanno ancora sviluppato patologie. L\u2019efficacia dell\u2019indivi- duazione dell\u2019AD tra gli assistiti da parte dei MMG potrebbe essere incrementata usando congiuntamente la competenza dei MMG e quella dei questionari standardizzati sul consumo di alco

General practitioners recognizing alcohol dependence: a large cross-sectional study in 6 European countries

PURPOSE Although alcohol dependence causes marked mortality and disease burden in Europe, the treatment rate is low. Primary care could play a key role in reducing alcohol-attributable harm by screening, brief interventions, and initiating or referral to treatment. This study investigates identification of alcohol dependence in European primary care settings. METHODS Assessments from 13,003 general practitioners, and 9,098 interviews (8,476 joint number of interviewed patients with a physician\u2019s assessment) were collected in 6 European countries. Alcohol dependence, comorbidities, and health service utilization were assessed by the general practitioner and independently using the Composite International Diagnostic Interview (CIDI) and other structured interviews. Weighted regression analyses were used to compare the impact of influencing variables on both types of diagnoses. RESULTS The rate of patients being identified as alcohol dependent by the CIDI or a general practitioner was about equally high, but there was not a lot of overlap between cases identified. Alcohol-dependent patients identified by a physician were older, had higher rates of physicial comorbidity (liver disease, hypertension), and were socially more marginalized, whereas average consumption of alcohol and mental comorbidity were equally high in both groups. CONCLUSION General practitioners were able to identify alcohol dependence, but the cases they identified differed from cases identified using the CIDI. The role of the CIDI as the reference standard should be reexamined, as older alcohol- dependent patients with severe comorbidities seemed to be missed in this assessment