Volume 4, Issue 5 (Supplementary Issue - 2015)
Abstract
In this study, the effect of carbon and nitrogen sources, on production of yeast biomass was determined as well as the efficacy of various formulations of Candida membranifaciens to decrease blue mold on apple. The media containing sugar cane molasses as carbon sources caused more yeast growth than the media supplemented with permeate powder. Yeast extract as nitrogen source produced higher biomass than urea and Corn steep liquor (CSL). The best growth was obtained in medium that composed of sugar cane molasses, yeast extract and CSL. Viability of C. membranifaciens differed in various carriers significantly (p < 0.01). The number of viable cells in Kaolin and Talc-based formulations was gradually reduced whereas the viability in wheat bran based formulations increased in 4 months and then gradually declined. In general, the formulations stored at 4 °C had longer shelf life than those stored at 24 °C. The antagonistic efficacy of prepared formulations of C. membranifaciens was evaluated against Penicillium expansum on apple at storage conditions. There were no significant differences among Talc-based, Kaolin-based and Wheat bran-based formulations of C. membranifaciens in reduction of blue mold.
Maryam Mehdizadeh, Mojgan sheykhpour, Iman Salahshourifar, Seyed Davar Siadat, Parvaneh Saffarian,
Volume 12, Issue 2 (1-2022)
Abstract
Klebsiella pneumoniae is a gram-negative bacillus of the Enterobacteriaceae family. Despite being part of the natural human microflora, this is an opportunistic pathogen and a major cause of nosocomial infections. The increased emergence of multidrug resistance in Klebsiella pneumoniae has limited the treatment options for this bacterium. Carbon nanotubes (CNT), by improving the stability and solubulity of drugs, could increase the effectiveness of drugs for treatment. The aim of this study is to investigate the antibacterial effect of nanofluid containing functionalized multi-walled carbon nanotubes (f-CNT-NF) on Klebsiella pneumoniae isolated from clinical specimens. For the strain confirmation, biochemical ,API20E kit, and additional differential tests were performed, and antibiotic susceptibility test was performed by the disk diffusion method. The studied strain showed a resistance to all antibiotics such as cefepime.The minimum inhibitory concentration (MIC) was determined using the antibiotic micro dilution method. The MIC was determined in five effect modes including antibiotic (Ab), nanofluid containing functionalized multi-walled carbon nanotubes (f-CNT-NF) , nanofluid containing multi-walled carbon nanotubes (CNT-NF) ,Ab in combination with f-CNT-NF and Ab with CNT-NF. Nevertheless the individual effects of 10 µg mL-1 cefepime or 80 µg of nanofluid with f-CNT-NF did not inhibit the growth of the bacteria, but the co-administration of 10 µg mL-1 cefepime with 80 µg of the f-CNT-NF could inhibit the bacteria`s growth. It was concluded that f-CNT-NF could be more effective in drug delivery at lower concentrations than the free state, which could be used as a tool for optimal drug delivery.