Neste trabalho objetivou-se a produção de ácido cítrico por fermentação submersa utilizando meio sintético enriquecido com sacarose utilizando o fungo Aspergillus niger além de diferentes fontes de nitrogênio como o sulfato de amônio, a uréia e a peptona. A fermentação foi conduzida em frascos erlenmeyer e em estufa bacteriológica. Através dos resultados obtidos, constatou-se a produção de ácido cítrico em todos os meios fermentados testados. O uso de peptona associado a utilização do sulfato de amônio para o meio sintético de Prescott & Dunn, apresentou melhor produção (62,9 g/L.dia de ácido cítrico) sob as condições estudadas. Em relação ao tempo para a fermentação, foi constatado que o tempo de 24h é o ideal para maior produtividade no processo.

Inhibition of spoilage mold of common contaminant of bakery goods in modal agar system by potassium sorbate and calcium propionate in wide range of concentration (0 - 2000 ppm) at different pH (5.5 - 7) was investigated. All Samples were examined daily for mold growth. Results showed that both potassium sorbate and calcium propionate can be used effectively to inhibit mold growth and the effectiveness of these preservatives is enhanced by increasing the concentration and decreasing the pH. The effect of modified atmosphere packaging (MAP) comprised of 60% or 80% CO₂ (balance N₂) and oxygen absorbents on the growth of mold was also studied on the agar system. The results indicated that mold growth was prevented up to 42 days in packs flushed with 60% or 80% CO₂ (balance N₂). It was also evident that all samples did not show mold growth for >40 days when packaged in the presence of oxygen scavenger sachet

Background: Due to advancement of endourology, percutaneous nephrolithotomy (PCNL) is a common procedure for removal of renal stones. Intravascular absorption of normal saline during the PCNL may result in fluid overload, electrolyte imbalance and cardiovascular instability. Objective: To evaluate the changes in cardiovascular status and serum electrolyte levels in patients undergoing percutaneous nephrolithotomy. Method: Sixty adults underwent percutaneous nephrolithotomy were studied. Among them male female ratio was 13:7 and age ranging from 20-50 years. Heart rate, blood pressure and serum electrolytes were monitored before irrigation, during irrigation and post operatively. Stone size, duration of irrigation, volumes of irrigation fluid used and amount of absorption of irrigation fluid were recorded. Result: The mean heart rate, systolic and diastolic blood pressure levels were significantly higher (p<0.05) during PCNL compared to base line values. Serum sodium, potassium levels were decreased during the operation compared to the baseline levels (p < 0.005) but mean chloride concentration increased gradually compared to baseline but it was significantly higher at 120th min of irrigation and postoperatively (p<0.05). There was no significant change of serum bicarbonate concentration compared to base line value (p>0.05). The volume of irrigation fluid varied from 10000 ml to 24000 ml with mean volume 17045(±3383) ml. Total duration of irrigation varied from 30 min to 120 min. Total absorbed irrigant varied from 200-1000 ml with mean volume absorbed 526.27(±215) ml. Conclusion: In conclusion, these changes in cardiovascular status and serum electrolyte levels during percutaneous nephrolithotomy (PCNL) may be due to the invasive nature of the intervention to the kidney and the continuous irrigation of this vital organ. Bangladesh Journal of Urology, Vol. 22, No. 1, January 2019 p.3-7