Lipase Pseudomonas aeruginosa NR.22 (Ps.NR.22) in ethanol production by using agricultural waste: article

Ethanol is known as the most commonly used in biofuel, chemical solvents and preservatives. The demand of ethanol is rising due to the need for replacing fossil fuels in transportation sector. In this study, pineapple waste is used as an agricultural waste with Pseudomonas aeruginosa NR.22 as an active microorganism to produce ethanol. Unit operation that used in the study is Gas Chromatography (GC) and Fourier Transform Infrared Spectroscopy (FTIR). The objectives of the study are to produce ethanol from agricultural waste by lipase Pseudomonas aeruginosa NR.22 and to detect the concentration of ethanol. The study is conducted based on several method which is pretreatment of biomass, enzymatic hydrolysis, fermentation and product recovery. The whole fermentation process was carried out for 72 hours at 37℃ with initial pH of 6.8. Initial pH of the culture broth indicates as one of the most important environmental parameters that will affect production of lipase and bacterial growth. Initially, 5% (v/v) of 24 hours Pseudomonas aeruginosa NR.22 inoculum containing 5×106 cell/mL were used in this study. The value of lipase activity was 22.5±0.02U/mL with the oil removal recorded to be 58.2% with bacterial biomass of 5.95±0.001g/mL. From the result, it was found that the Pseudomonas aeruginosa NR.22 is able to utilize pineapple peels to produce ethanol without the need of supplying other nutrient. Ethanol yield at 72 hours fermentation reached 20.06 g/L with 31% purity. The untreated and treated substrates were analyzed by FTIR to check the modification of the structure appeared after this pretreatment which guides to efficient saccharification. The FTIR spectroscopic analysis of pineapple peels which classified under three conditions: untreated, treated and after saccharification of samples.