Repeated-batch ethanol fermentation from sweet sorghum juice by free cells of Saccharomyces cerevisiae NP 01

Low-cost inoculum preparation (IP) media for ethanol production were developed. It was found that sweet sorghum juice (SSJ) containing 100 g l-1 of total sugar without nutrient supplement could be used as the low-cost IP medium instead of the typical IP medium or yeast extract malt extract (YM) medium. Ethanol production from the SSJ (total soluble solids of 24 °Bx) by the inoculum of Saccharomyces cerevisiae NP 01 in batch and repeated-batch fermentations was then investigated. The fermentations were carried out under static condition in 500 ml air-locked Erlenmeyer flasks at 30°C and the initial yeast cell concentration was 1×108 cells ml-1. In the batch fermentation, the concentration (P), productivity (Qp) and yield (Yp/s) of ethanol were 110.09 ± 0.81 g l-1, 2.29 ± 0.01 g l-1 h-1 and 0.51 ± 0.02, respectively. In the repeated-batch fermentation, the yeasts could be used at least eight successive batches without a marked decrease in ethanol production. The repeated-batch fermentation with fill and drain volume at 75% of the working volume gave higher ethanol production efficiencies than those at 50% of the working volume in terms of total ethanol production rate (g h-1). The average P, Qp and Yp/s of the eight successive batches at 75% fill and drain volume in a 2 L bioreactor at the agitation rate of 100 rev min-1 were 93.30 ± 9.44 g l-1, 1.21 ± 0.43 g l-1 h-1 and 0.48 ± 0.03, respectively.Key words: Repeated-batch, ethanol fermentation, low-cost nutrient, sweet sorghum juice, Saccharomyces cerevisiae

Improvement of gas chromatographic analysis for organic acids and solvents in acetone-butanolethanol fermentation from sweet sorghum juice

Modern development for gas chromatographic peak recognition of organic acids and organic solvents in acetone-butanol-ethanol (ABE) fermentation was investigated under different temperature programmes. Either propanol or iso-butanol was used as an internal standard. The results showed that short retention time and fair recognition peak of the compounds were obtained under the following column temperature programme: 10 min at 150°C, 15°C/min to 180°C and 20 min at 180°C. The appearance of the chromatograms showed that iso-butanol allowed higher resolution and satisfactory peak shape for the tested compounds than propanol. Calibration curve between ratios of standard peak area per internal standard peak area and concentrations of the organic acids and organic solvents under these conditions had a good linear correlation with R2 ≥ 0.998. When ABE fermentation by Clostridium beijerinckii JCM1390 from sweet sorghum juice was carried out in a 2-L fermenter, the highest butanol concentration was 7.56 g/l with the butanol yield of 0.33 g/g sugar utilized.Key words: Acetone-butanol-ethanol fermentation, column temperature programme, gas chromatography, sweet sorghum juice

Effect of glutaraldehyde biocide on laboratory-scale rotating biological contactors and biocide efficacy

The effect of glutaraldehyde, a commercial biocide widely used in paper and pulp industry, on the performance of laboratory-scale rotating biological contactors (RBCs) as well as biocide efficacy was studied. Biofilms were established on the RBCs and then exposed to 0 - 180 ppm glutaraldehyde at a dilution rate of 1.60 h-1. The results showed that the biofilms became acclimated to glutaraldehyde and eventually could degrade it. Acclimation to the biocide took longer at the higher biocide concentrations. The degree of biocide degradation and chemical oxygen demand (COD) removal depended on acclimation period, the presence of other organic matters and the amount of mineral salts available. Glutaraldehyde at up to 80 ppm had no effect on treatment efficiency and populations of biofilms and planktonic phase of the system whereas glutaraldehyde at 180 ppm caused a progressive decline in all measured values. However, no glutaraldehyde concentration used in the study was sufficiently high to kill microorganisms in the RBC system. The presence of biofilm provided additional resistance to glutaraldehyde to bacteria because the biocide had to penetrate through biofilm to reach bacteria. The increased resistance of bacteria to glutaraldehyde due to acclimation should be considered in biocide applications

The use of dried spent yeast as a low-cost nitrogen supplement in ethanol fermentation from sweet sorghum juice under very high gravity conditions

Dried spent yeast (DSY) was used as a low-cost nitrogen supplement for ethanol fermentation from sweet sorghum juice under very high gravity (VHG) conditions by Saccharomyces cerevisiae NP 01. The fermentation was carried out at 30\ubaC in a 5-litre bioreactor. The results showed that DSY promoted ethanol production efficiencies. The ethanol concentration (P), productivity (Qp) and yield (Yp/s) of the sterile juice (total sugar of 280 g l-1) supplemented with 8 g l-1 of DSY were not different from those supplemented with yeast extract and/or peptone at the same amount. The initial yeast cell concentration of 5 x 107 cells ml-1 was found to be optimal for scale-up ethanol production. In addition, an increase in sugar concentration in inoculum preparation medium (from 10 to 100 g l-1) improved the ability of the inoculum to produce ethanol under the VHG conditions. When S. cerevisiae NP 01 grown in the juice containing 100 g l-1 of total sugar was used as the inoculum for ethanol fermentation, the P, Qp and Yp/s obtained were 108.98 \ub1 1.16 g l-1, 2.27 \ub1 0.06 g l-1 h-1 and 0.47 \ub1 0.01 g g-1, respectively. Similar results were also observed when the ethanol fermentation was scaled up to a 50-litre bioreactor under the same conditions. The cost of the sweet sorghum for ethanol production was US$ 0.63 per litre of ethanol. These results clearly indicate the high potential of using sweet sorghum juice supplemented with DSY under VHG fermentation for ethanol production in industrial applications

Ethanol production from sweet sorghum juice under very high gravity conditions: Batch, repeated-batch and scale up fermentation

Batch ethanol fermentations from sweet sorghum juice by Saccharomyces cerevisiae NP 01 were carried out in a 500 ml air-locked Erlenmeyer flask under very high gravity (VHG) and static conditions. The maximum ethanol production efficiency was obtained when 9 g l-1 of yeast extract was supplemented to the juice. The ethanol concentration (P), productivity (Qp) and yield (Yp/s) were 120.24 \ub1 1.35 g l-1, 3.01 \ub1 0.08 g l-1 h-1 and 0.49 \ub1 0.01, respectively. Scale up ethanol fermentation in a 5-litre bioreactor at an agitation rate of 100 rev min-1 revealed that P, Qp and Yp/s were 139.51 \ub1 0.11 g l-1, 3.49 \ub1 0.00 g l-1 h-1 and 0.49 \ub1 0.01, respectively, whereas lower P (119.53 \ub1 0.20 g l-1) and Qp (2.13 \ub1 0.01 g l-1 h-1) were obtained in a 50-litre bioreactor. In the repeated-batch fermentation in the 5-litre bioreactor with fill and drain volume of 50% of the working volume, lower P and Qp were observed in the subsequent batches. P in batch 2 to 8 ranged from 103.37 \ub1 0.28 to 109.53 \ub1 1.06 g l-1

Pregnancy and childbirth outcomes among adolescent mothers: A World Health Organization multicountry study

Tuvo como objetivo investigar el riesgo de resultados adversos del embarazo entre adolescentes en 29 países. El diseño utilizado fue un análisis secundario utilizando datos transversales basados en instalaciones de la Encuesta multipaís sobre salud materna y neonatal de la Organización Mundial de la Salud. Se tomó el análisis de veintinueve países de África, América Latina, Asia y Oriente Medio. La población estimada fue de mujeres ingresadas para el parto de 359 centros de salud durante 2 a 4 meses entre 2010 y 2011. Se utilizaron modelos de regresión logística multinivel para estimar la asociación entre la edad materna joven y los resultados adversos del embarazo. Se analizaron un total de 124 446 madres de ≤24 años y sus bebés. En comparación con las madres de 20 a 24 años, las madres adolescentes de 10 a 19 años tenían mayores riesgos de eclampsia, endometritis puerperal, infecciones sistémicas, bajo peso al nacer, parto prematuro y afecciones neonatales graves. El mayor riesgo de muerte neonatal temprana intrahospitalaria entre los bebés nacidos de madres adolescentes se redujo y fue estadísticamente insignificante después del ajuste por edad gestacional y peso al nacer, además de las características maternas, el modo de parto y la malformación congénita. La cobertura de los uterotónicos profilácticos, los antibióticos profilácticos para la cesárea y los corticosteroides prenatales para el parto prematuro a las 26 - 34 semanas fue significativamente menor entre las madres adolescentes. El embarazo adolescente se asoció con mayores riesgos de resultados adversos del embarazo. Las estrategias de prevención del embarazo y la mejora de las intervenciones de atención médica son cruciales para reducir los resultados adversos del embarazo entre las mujeres adolescentes en países de bajos y medianos ingresos

Pregnancy and childbirth outcomes among adolescent mothers: a World Health Organization multicountry study

Objective: To investigate the risk of adverse pregnancy outcomes among adolescents in 29 countries. Design: Secondary analysis using facility-based cross-sectional data of the World Health Organization Multicountry Survey on Maternal and Newborn Health. Setting: Twenty-nine countries in Africa, Latin America, Asia and the Middle East. Population: Women admitted for delivery in 359 health facilities during 2–4 months between 2010 and 2011. Methods: Multilevel logistic regression models were used to estimate the association between young maternal age and adverse pregnancy outcomes. Main outcome measures: Risk of adverse pregnancy outcomes among adolescent mothers. Results: A total of 124 446 mothers aged ≤24 years and their infants were analysed. Compared with mothers aged 20–24 years, adolescent mothers aged 10–19 years had higher risks of eclampsia, puerperal endometritis, systemic infections, low birthweight, preterm delivery and severe neonatal conditions. The increased risk of intra-hospital early neonatal death among infants born to adolescent mothers was reduced and statistically insignificant after adjustment for gestational age and birthweight, in addition to maternal characteristics, mode of delivery and congenital malformation. The coverage of prophylactic uterotonics, prophylactic antibiotics for caesarean section and antenatal corticosteroids for preterm delivery at 26–34 weeks was significantly lower among adolescent mothers. Conclusions: Adolescent pregnancy was associated with higher risks of adverse pregnancy outcomes. Pregnancy prevention strategies and the improvement of healthcare interventions are crucial to reduce adverse pregnancy outcomes among adolescent women in low- and middle-income countries

Use of antenatal corticosteroids and tocolytic drugs in preterm births in 29 countries: an analysis of the WHO Multicountry Survey on Maternal and Newborn Health

Background: Despite the global burden of morbidity and mortality associated with preterm birth, little evidence is available for use of antenatal corticosteroids and tocolytic drugs in preterm births in low-income and middle-income countries. We analysed data from the WHO Multicountry Survey on Maternal and Newborn Health (WHOMCS) to assess coverage for these interventions in preterm deliveries. Methods: WHOMCS is a facility-based, cross-sectional survey database of birth outcomes in 359 facilities in 29 countries, with data collected prospectively from May 1, 2010, to Dec 31, 2011. For this analysis, we included deliveries after 22 weeks’ gestation and we excluded births that occurred outside a facility or quicker than 3 h after arrival. We calculated use of antenatal corticosteroids in women who gave birth between 26 and 34 weeks’ gestation, when antenatal corticosteroids are known to be most beneficial. We also calculated use in women at 22–25 weeks’ and 34–36 weeks’ gestation. We assessed tocolytic drug use, with and without antenatal corticosteroids, in spontaneous, uncomplicated preterm deliveries at 26–34 weeks’ gestation. Findings: Of 303 842 recorded deliveries after 22 weeks’ gestation, 17 705 (6%) were preterm. 3900 (52%) of 7547 women who gave birth at 26–34 weeks’ gestation, 94 (19%) of 497 women who gave birth at 22–25 weeks’ gestation, and 2276 (24%) of 9661 women who gave birth at 35–36 weeks’ gestation received antenatal corticosteroids. Rates of antenatal corticosteroid use varied between countries (median 54%, range 16–91%; IQR 30–68%). Of 4677 women who were potentially eligible for tocolysis drugs, 1276 (27%) were treated with bed rest or hydration and 2248 (48%) received no treatment. β-agonists alone (n=346, 7%) were the most frequently used tocolytic drug. Only 848 (18%) of potentially eligible women received both a tocolytic drug and antenatal corticosteroids. Interpretation: Use of interventions was generally poor, despite evidence for their benefit for newborn babies. A substantial proportion of antenatal corticosteroid use occurred at gestational ages at which benefit is controversial, and use of less effective or potentially harmful tocolytic drugs was common. Implementation research and contextualised health policies are needed to improve drug availability and increase compliance with best obstetric practice

Time to Update and Quantitative Changes in the Results of Cochrane Pregnancy and Childbirth Reviews

BACKGROUND: The recommended interval between updates for systematic reviews included in The Cochrane Library is 2 years. However, it is unclear whether this interval is always appropriate. Whereas excessive updating wastes time and resources, insufficient updating allows out-of-date or incomplete evidence to guide clinical decision-making. We set out to determine, for Cochrane pregnancy and childbirth reviews, the frequency of updates, factors associated with updating, and whether updating frequency was appropriate. METHODOLOGY/PRINCIPAL FINDINGS: Cochrane pregnancy and childbirth reviews published in Issue 3, 2007 of the Cochrane Database of Systematic Reviews were retrieved, and data were collected from their original and updated versions. Quantitative changes were determined for one of the primary outcomes (mortality, or the outcome of greatest clinical significance). Potential factors associated with time to update were assessed using the Cox proportional hazard model. Among the 101 reviews in our final sample, the median time before the first update was 3.3 years (95% CI 2.7-3.8). Only 32.7% had been updated within the recommended interval of 2 years. In 75.3% (76/101), a median of 3 new trials with a median of 576 additional participants were included in the updated versions. There were quantitative changes in 71% of the reviews that included new trials (54/76): the median change in effect size was 18.2%, and the median change in 95% CI width was 30.8%. Statistical significance changed in 18.5% (10/54) of these reviews, but conclusions were revised in only 3.7% (2/54). A shorter time to update was associated with the same original review team at updating. CONCLUSIONS/SIGNIFICANCE: Most reviews were updated less frequently than recommended by Cochrane policy, but few updates had revised conclusions. Prescribed time to update should be reconsidered to support improved decision-making while making efficient use of limited resources

Caesarean section without medical indications is associated with an increased risk of adverse short-term maternal outcomes: the 2004-2008 WHO Global Survey on Maternal and Perinatal Health

<p>Abstract</p> <p>Background</p> <p>There is worldwide debate about the appropriateness of caesarean sections performed without medical indications. In this analysis, we aim to further investigate the relationship between caesarean section without medical indication and severe maternal outcomes.</p> <p>Methods</p> <p>This is a multicountry, facility-based survey that used a stratified multistage cluster sampling design to obtain a sample of countries and health institutions worldwide. A total of 24 countries and 373 health facilities participated in this study. Data collection took place during 2004 and 2005 in Africa and the Americas and during 2007 and 2008 in Asia. All women giving birth at the facility during the study period were included and had their medical records reviewed before discharge from the hospital. Univariate and multilevel analysis were performed to study the association between each group's mode of delivery and the severe maternal and perinatal outcome.</p> <p>Results</p> <p>A total of 286,565 deliveries were analysed. The overall caesarean section rate was 25.7% and a total of 1.0 percent of all deliveries were caesarean sections without medical indications, either due to maternal request or in the absence of other recorded indications. Compared to spontaneous vaginal delivery, all other modes of delivery presented an association with the increased risk of death, admission to ICU, blood transfusion and hysterectomy, including antepartum caesarean section without medical indications (Adjusted Odds Ratio (Adj OR), 5.93, 95% Confidence Interval (95% CI), 3.88 to 9.05) and intrapartum caesarean section without medical indications (Adj OR, 14.29, 95% CI, 10.91 to 18.72). In addition, this association is stronger in Africa, compared to Asia and Latin America.</p> <p>Conclusions</p> <p>Caesarean sections were associated with an intrinsic risk of increased severe maternal outcomes. We conclude that caesarean sections should be performed when a clear benefit is anticipated, a benefit that might compensate for the higher costs and additional risks associated with this operation.</p