Hp 8452a

The optical transparency of films was studied by UV-vis spectroscopy according to the ASTM D1746-09 recommendations. Specifically, film samples were cut into rectangles and placed in a spectrophotometer cell. The absorbance spectrum (420–640 nm) was recorded for each sample using a diode array spectrophotometer (HP8452A, Hewlett Packard, Palo Alto, CA, USA). Absorbance value at 550 nm wavelength was used to calculate the transmittance percentage (T%), the index of film transparency, according to the following equation: $A=\log \frac{100}{T\%}=2-\log T\%$
For each sample, the analysis was repeated five times.

The absorbance of the samples was determined at 555 nm using an Ektachem DT 60 clinical chemistry analyzer (Eastman Kodak, Rochester, NY, USA) to analyze plasma lactate levels. Plasma MDA levels were analyzed using a BIOXYTECH LPO-586 kit (Oxis International, Beverly Hills, CA, USA). A 200-μL aliquot of plasma or standard was mixed with 640 μL of diluted N-methyl-2-phenylindole. Thereafter, 150 μL of concentrated hydrochloric acid was added, mixed, and incubated at 45 °C (60 min). After cooling, the absorbance values of the standards and samples were read at 586 nm using a spectrophotometer (HP 8452A; Hewlett-Packard, Palo Alto, CA, USA). Plasma SOD activity was analyzed using a tetrazolium-based kit (IBL, Hamburg, Germany). A 200 μL sample of the diluted radical detector and 10 μL plasma sample were added to prepared standard wells. Next, 20 μL of diluted xanthine oxidase was divided into the wells, mixed for several seconds, and incubated at 18–20 °C for 20 min. The absorbance was measured at 450 nm using a spectrophotometer (Tecan Sunrise; TECAN GmbH, Salzburg, Austria).

Sterile 300 mL Erlenmeyer flasks closed with bacteriological plug containing 100 mL of LB media were inoculated with E. coli ARL1 from agar plate. Kanamycin stock solution was added in amount of 0.5 mL to get final concentration of 50 mg/L. The flask was placed on a rotary shaker and incubated overnight at 37 °C, 200 rpm. Overnight culture (3 mL) was inoculated into a fresh LB medium with kanamycin and incubated at the same conditions as the overnight culture to the approximate absorbance of A₆₀₀ = 0.35 (~0.6 × 10⁸ CFU·mL⁻¹) in order to get bacteria in exponential growth phase. OD was determined in 1 cm cuvette at 600 nm by UV-VIS spectrophotometer HP8452A (Hewlett-Packard, Palo Alto, CA, USA). The bacterial cells were centrifuged for 10 min at 2264× g (Hettich Universal 32R, Andreas Hettich, Tuttlingen, Germany), the pellet was resuspended in PBS with glucose (40 mmol·L⁻¹) and tryptone (10 g/L) to a cell concentration of 1.2 × 10⁸ CFU·mL⁻¹. This suspension was used for bioluminescence induction as soon as possible (within less than 10 min).

Saccharomyces cerevisiae was obtained from Collection of microorganisms of the Institute of Biochemistry and Microbiology UCT Prague. Overnight culture (50 mL) was added into the bioreactor. Optical density (OD) of the overnight culture (3× diluted) was 0.5.
OD was determined in 1 cm cuvette at 600 nm by UV–VIS spectrophotometer HP8452A (Hewlett-Packard, Palo Alto, CA, USA).