Bacterial cellulose (BC) is a type of biopolymer produced as primary metabolism product by many genera of bacteria such as Acetobacter, Rhizobium, Agrobacterium, Psuedomonas and Sarcina. This article aimed to study the effect of some factors on cellulose production from Rhizobium leguminosarum bv. viciae which isolated from root nodules of Vicia faba plant collected from Abu-Ghraib in Baghdad. Some environmental and nutritional factors were examined including : carbon and nitrogen sources, pH, temperature and incubation period. Results showed that maximum production of cellulose was gained by Hestrin-Schram medium (HS medium) containing 2% fructose as carbon source, 1% yeast extract as nitrogen source, as well as optimum pH, temperature, and incubation period were (5, 30°C for 7 days) respectively .Cellulose dry weight was analyzed by Fourier transform infrared spectroscopy (FTIR) technique and the results showed the presence of the functional groups of bacterial cellulose.

Introduction and Aim: Klebsiella pneumoniae is a Gram-negative bacterium responsible for a wide range of infections, including respiratory tract infections (RTIs). This research was aimed to study the antibacterial and anti-biofilm effect of AgNPs produced by Gram positive and negative bacteria on RTIs associated with K. pneumoniae.   Materials and Methods: The biofilm formation of K.  pneumoniae was determined by tube method qualitatively from select bacterial species characterized by UV-Visible spectroscopy. The antibacterial susceptibility of the bacteria AgNPs was tested for their antibacterial and antibiofilm activity on a clinical isolate of K. pneumoniae.   Results: K. pneumoniae isolated from RTIs were strong biofilm producers.  The antibacterial activity of AgNPs synthesized from bacterial spp in this study had good antibacterial activity against K. pneumoniae. P. aeruginosa and P. mirabilis AgNPs had the strongest anti-biofilm effect, with 84% and 83%, respectively, while A. baumanii's AgNPs had the lowest (79%). AgNPs of P. aeruginosa and P. luteola showed the highest (80%) anti-biofilm action against the development of pre- and post-mature biofilms formed by K. pneumoniae, while AgNPs from S. mitis exhibited the lowest levels (69%).   Conclusion: AgNPs generated by Gram positive and Gram-negative bacteria, when exposed to K. pneumoniae isolated from RTIs had a good antibacterial impact and inhibited the formation of biofilm by K. pneumonia and hence could be used as an antibacterial agent against K. pneumoniae infecting the respiratory tract.