Hyperexpression of two Aspergillus niger xylanase genes in Escherichia coli and characterization of the gene products

The analysis of individual gene product should enable to clarify the role of a particular enzyme in a complex xylanase system of A. niger. The two genes encoding precursors of co-produced endo-1,4-¥â-D-xylanases, xynA1 and xynB, were isolated from Aspergillus niger SCTCC 400264 (SCTCC, China) by using RT-PCR technique and then successfully expressed in Escherichia coli BL21. The nucleotide sequences of the xynA1 and xynB genes revealed that they were only 52.5 percent homology to each other. Characterization of the recombinant enzymes revealed the different properties: the specific activity of recombinant XYNA1 was 16.58 U/mg compared to 1201.7 U/mg for recombinant XYNB; The optimum temperature and pH of the recombinant XYNA1 were 35 ¨¬C and 3.0, respectively, whereas the corresponding values for the recombinant XYNB were 55 ¨¬C and 5.0, respectively; The recombinant XYNB showed much more thermostability than recombinant XYNA1; The recombinant XYNB showed 94 percent of maximal activity after incubating in water for 60 min at 60 ¨¬C compared to no activity for recombinant XYNA1. Various metal ions had different effects on activity between the two recombinant xylanases.

Un caso de otomicosis causada por Aspergillus niger, Aspergillus sp. y Candida albicans / One case of otomicosis by Aspergullus niger, Aspergillus sp and Candida albins

se registra un caso de otitis crónica no asociada a infección bacteriana, rebelde al tratamiento convencional, causada por Aspergillus niger, Aspergillus sp. y Candida albicans.

Chronic Endopath thelitis after extract Sular cataract extraction caused by Aspergillus niger

Chronic postoperative endophthalmitis is a distinct clinical entity that describes eridophthalmitis that presents one or more months after cataract surgery and which is associated with micro organisms of low-grade virulence. This study concerns the case of a 65-year-old man in whom chronic endophthalmitis developed three months after extracapsular cataract extraction with implantation of a posterior chamber intraocular lens. Aspergillus niger was isolated and identified from the infiltrate which was recovered from the anterior chamber of the left eye. The infection responded to combined medical and surgical treatment

Aislamiento de diversas especies del género aspergillus de la tierra de plantas ornamentales intrahospitalarias / Isolation of different aspergillus strains fron the soil of ornamental plants located at hospital

The earth of ornamental plants is one of the main reservoirs of Aspergillus type of fungi in hospital areas. We studied 174 ornamental interior plants from a hospital at Santiago. Samples were obtained from the soil surface and sowed in Sabouraud-glucose agar, adding streptomycin and G-penicillin. After 72 h of culture, at least one strain of Aspergillus was isolated from 140 samples (80.5 percent). The most frequently isolated strain was A fumigatus (129 samples), followed by A miger (75 samples). A fumigatus and A niger were the only isolated strains in 65 and 11 samples respectively. These findings confirm that ornamental plants can be important reservoirs of Aspergillus strains, a potential infectious agent for immunocompromised patients in hospital areas

Chenopodium oil: a new topical antifungal agent in otomycosis- [1] in vitro study

The search for new antifungal drugs for treatment of otomycosis is still continuing as there is currently no widely accepted, effective drug for eradication of otomycosis. The idea of investigating the antifungal effect of chenopodium oil was based on the observation that the plant extract was successfully used by natives to treat oral thrush in children. The study aimed at in vitro evaluation of the effect of chenopodium oil on the most common fungi causing otomycosis. Seventy patients [82 ears] with otomycosis were subjected to mycological study. The most commonly isolated fungi were Aspergillus niger [67%], Aspergillus flavus [14.6%], Candida albicans [9.8%], Aspergillus fumigates [6.1%]. These four fungi were used in this in vitro study. The results of this study indicated that chenopodium oil has got a definite fungicidal effect on the four tested fungi. The minimal inhibitory concentration [MIC] was 0.09% for A. niger, A. flavus and A. fumigates, while it was 0.08% for C. albicans effects