Biotransformation of germacranolide from Onopordon leptolepies by Aspergillus niger

Terpenes are present in the essential oils obtained from herbs and spices. They are produced by these plant species as a chemical defense mechanism against phytopathogenic microorganisms. Therefore, terpenes have attracted great attention in the food industry, e.g., they have been used in foods such as cheese as natural preservatives to prevent fungal growth. Herein, we describe the microbial transformation of onopordopicrin [1] by Aspergillus niger. Four product 11alpha H-dihydroonopordopicrin [2], 11beta H-dihydroonopordopicrin [3], 3beta-hydroxy-11beta Hdihydroonopordopicrin [4], and 14-hydroxy-11 beta H-dihydroonopordopicrin [5] were obtained. Their structures were identified on the basis of chemical and spectroscopic data. All the four compounds were novel

Screening of urease production by Aspergillus niger strains

In this study, urease production was investigated among thirteen strains of Aspergillus niger; seven strains isolated from soils of Semnan province in Iran and six strains obtained from Persian Type Culture Collection [PTCC]. The enzyme production was screened in two submerged media quantitatively. The registered PTCC 5011 and the native S31 strains showed more urease production than the other eleven strains. The maximum enzyme productions by PTCC 5011 and S31 strains were 106 and 109 U.g-1dry mass in submerged culture, respectively. Also, we used two solid media for screening all of the strains for urease production semi quantitatively. Due to the acceptable correlations between the two methods, the latter can be used as an ancillary method to mass screening of urease production by filamentous fungi

Bacteria due to catheterization in hospitalized patients

In this survey, made to determine instances of bacteriuria occurring in hospitalized patients who had undergone catheterization, 259 urine specimens were taken from 103 patients admitted to three hospitals in Tehran. Of the 73 patients who had no urinary tract infection or contamination, 40 [54.8%] developed bacteriuria at the end of catheterization. Incidence of bacteriuria in patients under age 40 was 55.5%, and 53.5% in patients over age 40. The organisms that were isolated from the urine cultures of the patients were most often gram negative bacilli of Enterobacteriaceae, among which E. coli [38%] and Klebsiella pneumoniae [17%] had the highest frequency