Elżbieta Lalke-Porczyk

Chitinolytic activity of bacteria and fungi isolated from shrimp exoskeletons

Chitinolytic activity of bacteria and fungi isolated from shrimp exoskeletons Microbiological analysis of shrimp exoskeletons demonstrated considerable differences in abundance of heterotrophic bacteria and fungi. The number of heterotrophic bacteria was greater by two orders of magnitude than that of fungi. The survey, however, did not reveal significant differences in abundances of bacteria and fungi in samples collected during different months of the survey. The percent contribution of chitinolytic fungi in shrimp exoskeletons was greater than that of bacteria that hydrolyze chitin. The activity of chitinase bacteria was always higher than fungi. Chitinases produced by bacteria demonstrated the highest level of activity at 40°C and pH = 8. In contrast, fungal chitinases showed the highest activity at 50°C and pH = 5.

Influence of the Root System of the Common Osier (Salix viminalis L.) on Abundance of Heterotrophic Bacteria in the Willow Sewage Treatment System

The impact of the Common Osier (Salix viminalis L.) root system on number (CFU) of heterotrophic bacteria and their production in a soil-willow filter was examined. The Osier rhizosphere was found to be suitable habitat for growth of the examined microbial group, and the root system stimulated development of heterotrophic bacteria. The rhizosphere bacteria to control soil bacteria (R:C) ratio oscillated between 2.48 and 2.75 depending on the location of sample collection. The highest abundance of bacteria as well as highest bacterial production was observed at location I, near sewage discharge onto the plot. There was a significant positive correlation between the number of heterotrophic bacteria and the bacterial production.