BIOSURFACTANT PRODUCTION USING LIGNOCELLULOSIC MATERIAL FOR BIOPESTICIDE ACTIVE COMPOUND

• Main Author: Setia Adiandri, Resa
• Format: Dissertations
• Language: Indonesia
• Subjects: Teknik kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/79250
• Institution: Institut Teknologi Bandung

Biosurfactants are amphiphilic compounds with hydrophilic and hydrophobic groups within a single molecule. Biosurfactants exhibit antimicrobial, antifungal, and insecticidal properties. These biosurfactant capabilities are highly relevant in the control of plant pest organisms (PPOs). In the production of biosurfactants, the product yield is greatly influenced by various factors, including the type and productivity of microorganisms, inducers, and raw materials/substrates, which affect biosurfactants' production costs. The research aims to study biosurfactant production using lignocellulosic materials for biopesticide active compounds. Meanwhile, the specific research objectives are: (1) identifying biosurfactant-producing bacteria of the genus Bacillus on glucose and xylose substrates, (2) assessing the performance of selected Bacillus bacteria for biosurfactant production on glucose and xylose substrates with the addition of palm oil as a hydrophobic inducer, (3) evaluating the performance of selected Bacillus bacteria for biosurfactant production on lignocellulosic corncob substrates, and (4) determining the parameter values of Monod and Contois's kinetic models combined with Luedeking-Piret in the biosurfactant production process from corncob lignocellulosic material. Based on the research results, it is concluded that four out of six bacterial isolates used in biosurfactant production can produce biosurfactants in media containing glucose and xylose carbon sources. These bacteria are Bacillus subtilis ITBCC46 (B. subtilis ITBCC46), B. subtilis ITBCC40, B. subtilis ITBCC31, and B. siamensis ITBCC36. All biosurfactants produced by these Bacillus species reduced the surface tension to below 40 mN/m (ranging from 32.70?39.15 mN/m) and had emulsification stability exceeding 50%. Three selected bacteria, B. subtilis ITBCC46, B. subtilis ITBCC40, and B. subtilis ITBCC31, were tested for biosurfactant production by adding palm oil as a hydrophobic inducer. The results showed that these three Bacillus species could produce biosurfactants in media containing glucose and xylose substrates by adding 1?5% palm oil as a hydrophobic inducer. The produced biosurfactants belong to the lipopeptide group and are anionic. GC-MS analysis revealed that the biosurfactants contained thiazole or thiazolyl groups. Fatty acids, with palmitic acid as the primary component, were also identified in the biosurfactants. With these compound contents, biosurfactants have the potential to be applied in biopesticide formulations as fungicides and bactericides targeting plant pests such as fungi and bacteria. B. subtilis ITBCC31 was selected to test the biosurfactant production performance on lignocellulosic corncob hydrolysate substrates. The testing results indicated hydrolysate from enzymatic lignocellulosic corncob material could be used as a carbon source for biosurfactant production. This was demonstrated by the increased cell concentration, biosurfactant production, and decreased substrate concentration in the hydrolysate. The biosurfactant produced belongs to the anionic biosurfactant group and can reduce surface tension to 39.80 mN/m while maintaining emulsion stability. GC-MS analysis revealed that the dominant compound in this biosurfactant is 3,4-dihydroxy acetophenone, which is known to have antimicrobial activity, especially against gram-positive bacteria. The kinetic reaction model based on the research data indicates that the Monod and Contois kinetic models combined with the Luedeking-Piret (LP) model can describe the kinetic characteristics of the biosurfactant production process, whether with a single substrate or multiple substrates. Based on the obtained values of ? and ?, the growth-associated product relationship is established for the growth of cells and the biosurfactant product synthesized by B. subtilis ITBCC31.