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The biodegradation of phenol, m-cresol and 4-chlorophenol by the pure and mixed culture of Pseudomonas putida and Candida tropicalis was investigated. The results showed that,with the initial concentrations of 100, 50 and 60 mg x L(-1) for phenol, m-cresol and 4-chlorophenol, respectively,and an increase in the absolute value of the kinetic constant k of 19.0%, 2.6% and 46.4% for the degradation of phenol, m-cresol and 4-chlorophenol, respectively, was reached by dual culture compared with pure culture. The activity assays of phenol hydroxylase and catechol 1, 2-dioxygenase demonstrated phenol was degraded via the ortho-cleavage pathway in both of the two species. Further experiments via high performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry techniques (LC-MS) suggested the degradation of three phenolic compounds could be accelerated due to co-metabolism by Pseudomonas putida of cis, cis-muconic acid, and 4-carboxymethylenebut-2-en-4-olide accumulated in phenol and 4-chlorophenol degradation, respectively, 3, 4-dihydroxybenzoic acid, 2-maleylacetate, and 3-oxoadipate in the degradation of m-cresol by Candida tropicalis in dual culture.

Objective: To investigate the epidemiological features of patients with nosocomial invasive fungal infection., Methods: Fungi in blood were identified by BacT ALERT 3D, other clinical samples were cultured by Sabouraud's dextrose agar (SDA) medium. Candidas were isolated and identified by CHRO Magar candida color medium. Fungus-cultured positive cases from Jan. 2004 to Nov. 2007 were analyzed on items as patients' age, underlying disease, sample, strain, and species distribution. All statistical analyses were carried out by SPSS 13.0., Results: The overall incidence rate of invasive fungal infections was 4.12%. The average age of patients was 7 - 96 with most patients were male, with geriatric problems and different kinds of underlying diseases. Lower respiratory tract infection was the most frequent infection site, followed by urinary tract, gastrointestinal tract. The main pathogens of invasive fungal infections were Candidas (93.80%). Strains of Candida albicans were the most frequent organisms which accounted for 67.29% of all the isolates. Mould fungus infections accounted for only 6.20%. During the 4 years of observation, the detection rate of fungi, specimen sources and the distribution of species and compartment were different with significant differences (P < 0.0083)., Conclusion: The epidemiological properties such as the source of specimen, the distribution of species and composition sections of invasive fungal infections were changing. Candida spp. were still the main pathogens of invasive fungal infections but the sections of fungi changed. The incidence of Aspergillus infections had been increasing recently.