Combination Of Biochemical Characteristics Research Articles

Analysis of Phenol Biodegradation in Antibiotic and Heavy Metal Resistant Acinetobacter lwoffii NL1.

Phenol is a common environmental contaminant. The purpose of this study was to isolate phenol-degrading microorganisms from wastewater in the sections of the Chinese Medicine Manufactory. The phenol-degrading Acinetobacter lwoffii NL1 was identified based on a combination of biochemical characteristics and 16S rRNA genes. To analyze the molecular mechanism, the whole genome of A. lwoffii NL1 was sequenced, yielding 3499 genes on one circular chromosome and three plasmids. Enzyme activity analysis showed that A. lwoffii NL1 degraded phenol via the ortho-cleavage rather than the meta-cleavage pathway. Key genes encoding phenol hydroxylase and catechol 1,2-dioxygenase were located on a megaplasmid (pNL1) and were found to be separated by mobile genetic elements; their function was validated by heterologous expression in Escherichia coli and quantitative real-time PCR. A. lwoffii NL1 could degrade 0.5 g/L phenol within 12 h and tolerate a maximum of 1.1 g/L phenol, and showed resistance against multiple antibiotics and heavy metal ions. Overall, this study shows that A. lwoffii NL1 can be potentially used for efficient phenol degradation in heavy metal wastewater treatment.

Сравнительный анализ питательных сред для определения биохимических свойств энтеробактерий

The stage of identification of microorganisms is one of the most important and time-consuming stages of conducting bacteriological studies. On nutrient media with primary isolation by a combination of biochemical characteristics, several genera of enterobacteria can be detected simultaneously. Therefore, an important condition for the effectiveness of bacteriological studies to isolate representatives of the Enterobacteriaceae family is an adequate selection and quality of culture media. This allows you to determine the phenotypic properties of the grown cultures of microorganisms and correctly identify them. A comparative assessment of the biological properties of a number of modern nutrient media was carried out to determine the cultural-morphological and biochemical properties of enterobacteria. Key words: nutrient media, enterobacteria, phenotypic features, biochemical properties, differentiating properties, selectivity